Egg maturation by the glassy-winged sharpshooter (Hemiptera: Cicadellidae); a vector of Xylella fastidiosa

USDA-ARS?s Scientific Manuscript database

Rates of spread of insect-transmitted plant pathogens are a function of vector abundance. Despite this, factors affecting population growth rates of insects that transmit plant pathogens have received limited attention. The glassy-winged sharpshooter (Homalodisca vitripennis) feeds on xylem-sap and ...

Regulator of G-protein signaling 2 (RGS2) suppresses premature calcium release in mouse eggs

PubMed Central

Bernhardt, Miranda L.; Lowther, Katie M.; Padilla-Banks, Elizabeth; McDonough, Caitlin E.; Lee, Katherine N.; Evsikov, Alexei V.; Uliasz, Tracy F.; Chidiac, Peter; Williams, Carmen J.; Mehlmann, Lisa M.

2015-01-01

During oocyte maturation, capacity and sensitivity of Ca2+ signaling machinery increases dramatically, preparing the metaphase II (MII)-arrested egg for fertilization. Upon sperm-egg fusion, Ca2+ release from IP3-sensitive endoplasmic reticulum stores results in cytoplasmic Ca2+ oscillations that drive egg activation and initiate early embryo development. Premature Ca2+ release can cause parthenogenetic activation prior to fertilization; thus, preventing inappropriate Ca2+ signaling is crucial for ensuring robust MII arrest. Here, we show that regulator of G-protein signaling 2 (RGS2) suppresses Ca2+ release in MII eggs. Rgs2 mRNA was recruited for translation during oocyte maturation, resulting in ∼20-fold more RGS2 protein in MII eggs than in fully grown immature oocytes. Rgs2-siRNA-injected oocytes matured to MII; however, they had increased sensitivity to low pH and acetylcholine (ACh), which caused inappropriate Ca2+ release and premature egg activation. When matured in vitro, RGS2-depleted eggs underwent spontaneous Ca2+ increases that were sufficient to cause premature zona pellucida conversion. Rgs2−/− females had reduced litter sizes, and their eggs had increased sensitivity to low pH and ACh. Rgs2−/− eggs also underwent premature zona pellucida conversion in vivo. These findings indicate that RGS2 functions as a brake to suppress premature Ca2+ release in eggs that are poised on the brink of development. PMID:26160904

Egg production and oviposition in the tobacco budworm: effect of age at mating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Proshold, F.I.; Karpenko, C.P.; Graham, C.K.

1982-01-01

Female tobacco budworms, Heliothis virescens (F.) (Lepidoptera: Noctuidae), that emerged in the laboratory contained no mature eggs, although ooecyte development had proceeded as far as yolk deposition in the ultimate egg of each ovariole. After 18 h, ca. one mature egg per ovariole was present. If the females subsequently remained unmated, maturation of additional eggs was curvilinear with age and leveled off at ca. 500 eggs per female at 120 h. If the females mated, there was an inverse relationship between egg production and age mated; maximal production occurred when females mated the first night postemergence (ca. 30 h), andmore » production then diminished until females mating at 5 days or more laid only slightly more eggs than virgin females. However, there was also a direct relationship between length of life and age of mating. Females that mated at 1 or 2 days showed a signficant correlation between numbers of eggs produced and longevity and between numbers of eggs and pupal weight. Virgin females and females that mated at 3 days showed a significant correlation between eggs and longevity but not between eggs and pupal weight. There was no significant correlation between eggs and pupal weight or longevity for females that mated at 5 days or later.« less

Evaluation of jojoba meal as a potential supplement in the diet of broiler breeder females during laying.

PubMed

Vermaut, S; De Coninck, K; Bruggeman, V; Onagbesan, O; Flo, G; Cokelaere, M; Decuypere, E

1999-05-01

1. This study was undertaken to investigate whether jojoba meal can be used as a food supplement during the laying period of chickens. 2. The size of eggs laid were smaller and the overall production rate was lower compared to control birds on food without jojoba meal supplementation. Furthermore, both ovary and oviduct weights were lower in jojoba fed birds. 3. This lowering of egg size and production rate was caused by factors present in jojoba which interfere with follicle growth, yolk deposition, progesterone production and the follicular maturation processes, resulting in the ovulation of smaller follicles and a lower ovulation rate.

Differential immunosuppression by Campoletis chlorideae eggs and ichnovirus in larvae of Helicoverpa armigera and Spodoptera exigua.

PubMed

Han, Li-Bin; Yin, Li-Hong; Huang, Ling-Qiao; Wang, Chen-Zhu

2015-09-01

The ichneumonid wasp, Campoletis chlorideae Uchida, successfully develops in the cotton bollworm Helicoverpa armigera (Hübner), but rarely survives in the beet armyworm Spodoptera exigua (Hübner) due to the encapsulation by host immunity. In this study, we investigated the role of C. chlorideae ichnovirus (CcIV) and eggs in the evasion of the host immune system. Washed eggs of different types, immature, mature, newly laid, or pretreated with protease K, were injected alone or with the calyx fluid containing CcIV into the larvae of H. armigera and S. exigua. In H. armigera, when injected with washed eggs alone, only 9.5% of the mature eggs were encapsulated at 24h post-injection. This is much lower than that of the immature eggs (100%), mature eggs pretreated with protease K (100%) and newly laid eggs (54.4%). No encapsulation was observed when the washed eggs were co-injected with calyx fluid at 24h post-injection. Conversely, the eggs in all treatments were encapsulated in S. exigua. Electron microscopic observations of parasitoid eggs showed structural differences between the surfaces of the mature and other kinds of eggs. The injected CcIV decreased the numbers of host hemocytes and suppressed the spreading ability of plasmatocytes and granulocytes in H. armigera, but had little effect on the hemocytes from S. exigua. In conclusion, the C. chlorideae egg provides a passive protection against encapsulation by itself, and CcIV supplies an active protection through disrupting host immune responses. These coordinated protections are host-specific, implying their role in host range determination. Copyright © 2015 Elsevier Inc. All rights reserved.

ELASTICITY ANALYSIS OF AMPHIBIAN LIFE HISTORIES

EPA Science Inventory

By comparing life history parameters (e.g., age at metamorphosis, age at sexual maturation, egg number, longevity) and phenology of different species, we gain valuable insight into why growth rates differ across populations. Although the demography of most amphibians is lacking, ...

EGG-HATCHING MECHANISM OF HUMAN LIVER FLUKE, OPISTHORCHIS VIVERRINI: A ROLE FOR LEUCINE AMINOPEPTIDASES FROM THE SNAIL HOST, BITHYNIA SIAMENSIS GONIOMPHALOS.

PubMed

Tesana, Smarn; Khampoosa, P; Piratae, S; Prasopdee, S; Sripanidkulchai, B

2018-05-08

The human liver fluke Opisthorchis viverrini (Platyhelminthes, Trematoda, Digenea) uses snails of the genus Bithynia as first intermediate host. Peculiarly among trematodes, the eggs of O. viverrini hatch within the digestive tract of its snail host. It remains uncertain whether hatching in this species is mediated through mechanical fracture of the eggshell or by digestion with specific digestive enzymes. This study aimed to characterize enzymes with specific inhibitor and factors involved in the hatching activity of O. viverrini eggs. For measuring egg hatching in vivo, 50 O. viverrini mature eggs were fed to individual Bithynia siamensis goniomphalos snail at various temperature conditions for 24 hrs. Ex vivo, mature eggs were incubated with crude snail extract and commercial leucine aminopeptidase (LAP). Egg-hatching of O. viverrini was temperature dependent, with optimal hatching occurring at 24-28 C, with a peak of hatching of 93.54% in vivo and 30.55% ex vivo occurring at these temperatures. Ex vivo hatching rates increased to 45.87% under anaerobic conditions at 28 C. Some 22.70% and 16.21% of heat-killed eggs also hatched within the snail digestive tract and snail extract, respectively, indicating that host molecules are involved in the hatching response. Most eggs hatch in the anterior regions of the digestive tract. Hatching was completely inhibited in the presence of bestatin, an inhibitor of leucine aminopeptidase (LAP), but not in the presence of phosphatase inhibitors. Bestatin inhibition of hatching was reversible. Finally, egg hatching could be induced by addition of a porcine LAP. The results indicate that this digenean utilizes both LAP of the snail host and movement of miracidia for hatching.

Kisspeptin as a promising oocyte maturation trigger for in vitro fertilisation in humans.

PubMed

Kasum, Miro; Franulić, Daniela; Čehić, Ermin; Orešković, Slavko; Lila, Albert; Ejubović, Emina

2017-08-01

The aim of this review is to analyse the effectiveness of exogenous kisspeptin administration as a novel alternative of triggering oocyte maturation, instead of currently used triggers such as human chorionic gonadotropin (hCG) or gonadotropin releasing hormone (GnRH) agonist, in women undergoing in vitro fertilisation (IVF) treatment. Kisspeptin has been considered a master regulator of two modes of GnRH and hence gonadotropin secretion, pulses and surges. Administration of kisspeptin-10 and kisspeptin-54 induces the luteinising hormone (LH) surge required for egg maturation and ovulation in animal investigations and LH release during the preovulatory phase of the menstrual cycle and hypothalamic amenorrhoea in humans. Exogenous kisspeptin-54 has been successfully administered as a promising method of triggering oocyte maturation, following ovarian stimulation with gonadotropins and GnRH antagonists in women undergoing IVF, due to its efficacy considering achieved pregnancy rates compared to hCG and GnRH agonists. Also, its safety in patients at high risk of developing ovarian hyperstimulation syndrome is noteworthy. Nevertheless, further studies would be desirable to establish the optimal trigger of egg maturation and to improve the reproductive outcome for women undergoing IVF treatment.

Unfertilized frog eggs die by apoptosis following meiotic exit

PubMed Central

2011-01-01

Background A characteristic feature of frog reproduction is external fertilization accomplished outside the female's body. Mature fertilization-competent frog eggs are arrested at the meiotic metaphase II with high activity of the key meiotic regulators, maturation promoting factor (MPF) and cytostatic factor (CSF), awaiting fertilization. If the eggs are not fertilized within several hours of ovulation, they deteriorate and ultimately die by as yet unknown mechanism. Results Here, we report that the vast majority of naturally laid unfertilized eggs of the African clawed frog Xenopus laevis spontaneously exit metaphase arrest under various environmental conditions and degrade by a well-defined apoptotic process within 48 hours after ovulation. The main features of this process include cytochrome c release, caspase activation, ATP depletion, increase of ADP/ATP ratio, apoptotic nuclear morphology, progressive intracellular acidification, and egg swelling. Meiotic exit seems to be a prerequisite for execution of the apoptotic program, since (i) it precedes apoptosis, (ii) apoptotic events cannot be observed in the eggs maintaining high activity of MPF and CSF, and (iii) apoptosis in unfertilized frog eggs is accelerated upon early meiotic exit. The apoptotic features cannot be observed in the immature prophase-arrested oocytes, however, the maturation-inducing hormone progesterone renders oocytes susceptible to apoptosis. Conclusions The study reveals that naturally laid intact frog eggs die by apoptosis if they are not fertilized. A maternal apoptotic program is evoked in frog oocytes upon maturation and executed after meiotic exit in unfertilized eggs. The meiotic exit is required for execution of the apoptotic program in eggs. The emerging anti-apoptotic role of meiotic metaphase arrest needs further investigation. PMID:22195698

Effect of tributyltin on reproduction in Japanese whiting, Sillago japonica.

PubMed

Shimasaki, Yohei; Oshima, Yuji; Inoue, Suguru; Inoue, Yoshiyuki; Kang, Ik Joon; Nakayama, Kei; Imoto, Hisaya; Honjo, Tsuneo

2006-07-01

We examined the effect of tributyltin (TBT) on reproduction in the Japanese whiting, Sillago japonica. Mature fish were placed in indoor 500-L polyethylene tanks (five males and three females per tank) with a flow-through system and received dietary exposure to tributyltin oxide at concentrations of 2, 20, or 200 microg/g for 30 days during the active spawning period. Eggs spawned from the fish were collected daily, and the floating egg rate, larval deformity, hatchability, and viable hatch were monitored. TBT concentration in eggs of 200-microg/g group ranged from 85.0 to 159.6 ng/g in the evaluation period (days 5-30). In this period, the floating egg rate (83.2%), viable hatchability (82.2%), and total number of viable larvae (422,000 larvae per 100 g of female) were all significantly decreased in the 200-microg/g group compared with the control group (93.0%, 91.9%, and 709,000 larvae, respectively). The rate of deformity (2.6%) in the 200-microg/g group was about three times that in the control group (0.8%), although this difference was not significant. From these results, the lowest observed effect concentration of TBT in eggs on reproduction in Japanese whiting was estimated to be less than 159.6 ng/g-eggs.

Quantitative Aspects of the Development of Meloidogyne arenaria Larvae in Grapevine Varieties and Rootstocks.

PubMed

Ferris, H; Hunt, W A

1979-04-01

The development and productivity of parasitic stages of Meloidogyne arenaria were quantitatively defined in 14 varieties or rootstocks of grapevine. Mean development to maturity was related linearly to the number of degree-hours above 10 C temperature experienced from the time of penetration in all cultivars in which nematode adulthood was achieved. Averaged across varieties, 13,142 heat units were required for development of the mean individual to maturity. The standard deviation of the developing individuals about the mean, expressed as a proportion with 1 representing adulthood, did not differ with time or among varieties after 7,000 degree-hours had elapsed. Earliest egg production was observed after 7,662 degree-hours, averaged across varieties, considerably before mean development to maturity. Varieties were also ranked relative to the number of larvae establishing infection sites, and the rate of egg production per adult female. Varieties could he grouped according to their levels of horizontal resistance.

Ciona intestinalis as an emerging model organism: its regeneration under controlled conditions and methodology for egg dechorionation.

PubMed

Liu, Li-ping; Xiang, Jian-hai; Dong, Bo; Natarajan, Pavanasam; Yu, Kui-jie; Cai, Nan-er

2006-06-01

The ascidian Ciona intestinalis is a model organism of developmental and evolutionary biology and may provide crucial clues concerning two fundamental matters, namely, how chordates originated from the putative deuterostome ancestor and how advanced chordates originated from the simplest chordates. In this paper, a whole-life-span culture of C. intestinalis was conducted. Fed with the diet combination of dry Spirulina, egg yolk, Dicrateria sp., edible yeast and weaning diet for shrimp, C. intestinalis grew up to average 59 mm and matured after 60 d cultivation. This culture process could be repeated using the artificially cultured mature ascidians as material. When the fertilized eggs were maintained under 10, 15, 20, 25 degrees C, they hatched within 30 h, 22 h, 16 h and 12 h 50 min respectively experiencing cleavage, blastulation, gastrulation, neurulation, tailbud stage and tadpole stage. The tadpole larvae were characterized as typical but simplified chordates because of their dorsal nerve cord, notochord and primordial brain. After 8 - 24 h freely swimming, the tadpole larvae settled on the substrates and metamorphosized within 1- 2 d into filter feeding sessile juvenile ascidians. In addition, unfertilized eggs were successfully dechorionated in filtered seawater containing 1% Tripsin, 0.25% EDTA at pH of 10.5 within 40 min. After fertilization, the dechorionated eggs developed well and hatched at normal hatching rate. In conclusion, this paper presented feasible methodology for rearing the tadpole larvae of C. intestinalis into sexual maturity under controlled conditions and detailed observations on the embryogenesis of the laboratory cultured ascidians, which will facilitate developmental and genetic research using this model system.

Parthenogenesis in unfertilized eggs of Coturnix chinensis, the Chinese painted quail, and the effect of egg clutch position on embryonic development.

PubMed

Parker, H M; McDaniel, C D

2009-04-01

Parthenogenesis, embryonic development of an unfertilized egg, was studied for many years in turkeys. In fact, as many as 49% of unfertilized Beltsville Small White turkey eggs develop embryos. However, no research exists on parthenogenesis in quail. The Chinese painted quail is a close relative of the more common Japanese quail and, unlike turkeys or chickens, the small Chinese painted quail reaches sexual maturity rapidly, making it a great candidate for further research on parthenogenesis. Obviously, a better understanding of avian parthenogenesis should increase our knowledge of avian fertilization and early embryonic development. Therefore, we determined if unfertilized Chinese painted quail hens produce embryos. Second, we explored the possibility that position of the egg within the clutch influences parthenogenesis. When initial secondary sexual plumage was apparent at 4 wk of age, male chicks were separated from females to prevent fertilization. Hens were placed in individual cages near sexual maturity, at approximately 6 wk of age. Individual eggs were collected daily and labeled with hen number and date. Eggs were stored for 0 to 3 d at 20 degrees C before incubation at 37.5 degrees C. After 10 d of incubation, approximately 4,000 eggs from 300 laying hens were examined for embryonic development under a magnifying lamp. On average, 4.8% of the unfertilized eggs contained an abortive form of embryonic development consisting of undifferentiated cells and unorganized membranes. Approximately 27% of the laying hens produced at least 1 egg with parthenogenic development. However, about 10% (30) of these hens exhibited a predisposition for parthenogenesis by producing 2 or more unfertilized eggs with embryonic development. Twenty percent of the eggs from 2 hens produced embryonic development. Additionally, the first egg laid in a clutch was most likely to produce embryonic development, with a steady decline in the percentage of eggs with embryonic development as position in the clutch increased. In conclusion, the Chinese painted quail does exhibit parthenogenesis and clutch position influences the rate of naturally occurring parthenogenesis.

Biological variation in two Anopheles vestitipennis populations with different feeding preferences in southern Mexico.

PubMed

Ulloa, Armando; Rodríguez, Mario H; Arredondo-Jimenez, Juan I; Fernandez-Salas, Ildefonso

2005-12-01

The lengths of gonotrophic cycle and egg development and survival rate were studied in Anopheles vestitipennis collected in horse and human-baited traps in southern Mexico. The gonotrophic cycle duration was estimated using cross-correlation analysis, whereas the survival rate was assessed using a vertical method. Daily changes of parity rates gave significant correlation indices at 3 and 4 days in the zoophilic and anthropophilic populations, respectively. The minimum time required to develop mature eggs after blood feeding was 54 and 60 h, and the survival rate was 0.93 and 0.88 in zoophilic and anthropophilic female mosquito populations, respectively. These biological differences provide additional support for the existence of subpopulations with distinctive feeding preferences within An. vestitipennis in southern Mexico.

Effects of Xylem-Sap Composition on Glassy-Winged Sharpshooter (Hemiptera: Cicadellidae) Egg Maturation on High- and Low-Quality Host Plants.

PubMed

Sisterson, Mark S; Wallis, Christopher M; Stenger, Drake C

2017-04-01

Glassy-winged sharpshooters must feed as adults to produce mature eggs. Cowpea and sunflower are both readily accepted by the glassy-winged sharpshooter for feeding, but egg production on sunflower was reported to be lower than egg production on cowpea. To better understand the role of adult diet in egg production, effects of xylem-sap chemistry on glassy-winged sharpshooter egg maturation was compared for females confined to cowpea and sunflower. Females confined to cowpea consumed more xylem-sap than females held on sunflower. In response, females held on cowpea produced more eggs, had heavier bodies, and greater lipid content than females held on sunflower. Analysis of cowpea and sunflower xylem-sap found that 17 of 19 amino acids were more concentrated in cowpea xylem-sap than in sunflower xylem-sap. Thus, decreased consumption of sunflower xylem-sap was likely owing to perceived lower quality, with decreased egg production owing to a combination of decreased feeding and lower return per unit volume of xylem-sap consumed. Examination of pairwise correlation coefficients among amino acids indicated that concentrations of several amino acids within a plant species were correlated. Principal component analyses identified latent variables describing amino acid composition of xylem-sap. For females held on cowpea, egg maturation was affected by test date, volume of excreta produced, and principal components describing amino acid composition of xylem-sap. Principal component analyses aided in identifying amino acids that were positively or negatively associated with egg production, although determining causality with respect to key nutritional requirements for glassy-winged sharpshooter egg production will require additional testing. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Membrane junctions in Xenopus eggs: their distribution suggests a role in calcium regulation.

PubMed

Gardiner, D M; Grey, R D

1983-04-01

We have observed the presence of membrane junctions formed between the plasma membrane and cortical endoplasmic reticulum of mature, unactivated eggs of xenopus laevis. The parallel, paired membranes of the junction are separated by a 10-mn gap within which electron-dense material is present. This material occurs in patches with an average center-to-center distance of approximately 30 nm. These junctions are rare in immature (but fully grown) oocytes (approximately 2 percent of the plasma membrane is associated with junctions) and increase dramatically during progesterone-induced maturation. Junctions in the mature, unactivated egg are two to three times more abundant in the animal hemisphere (25-30 percent of the plasma membrane associated with junction) as compared with the vegetal hemisphere (10-15 percent). Junction density decreases rapidly to values characteristic of immature oocytes in response to egg activation. The plasma membrane-ER junctions of xenopus eggs are strikingly similar in structure to membrane junctions in muscle cells thought to be essential in the triggering of intracellular calcium release from the sarcoplasmic reticulum. In addition, the junctions' distinctive, animal-vegetal polarity of distribution, their dramatic appearance during maturation, and their disapperance during activation are correlated with previously documented patterns of calcium-mediated events in anuran eggs. We discuss several lines of evidence supporting the hypothesis that these junctions in xenopus eggs are sites that transduce extracellular events into intracellular calcium release during fertilization and activation of development.

Poor response cycles: when should we cancel? Comparison of outcome between egg collection, intrauterine insemination conversion, and follow-up cycles after abandonment.

PubMed

Nicopoullos, James D M; Abdalla, Hossam

2011-01-01

To determine optimal management with one or two mature follicles after stimulation. Retrospective analysis. Lister fertility clinic. A total of 1,350 IVF/intracytoplasmic sperm injection cycles (7.3% of total) during 1998-2009 were found to have one or two mature follicles. Group 1 (n = 807) comprised those who proceeded to vaginal egg collection (VEC) (59.8%; outcome per egg collection), group 2 (n=248) those who converted to IUI (18.4%; outcome per insemination) and group 3 (n=259) those who abandoned the current cycle (21.9%; outcome per abandoned cycle in first subsequent cycle). Live birth rate, clinical pregnancy rate, and biochemical pregnancy rate. Biochemical pregnancy rates of 13.1%, 4.9%, and 9.7%, clinical pregnancy rates of 8.1%, 3.6%, and 7.2%, and ongoing pregnancy rates of 6.8%, 2.0%, and 5.5% were achieved in groups 1, 2, and 3, respectively. All pregnancy outcomes were significantly higher after VEC (group 1) than for those converted to IUI (group 2), and all pregnancy outcomes were higher with borderline significance in group 3 vs. group 2. There was no significant difference in outcome between groups 1 and 3. Our data suggest that for such poor responders, proceeding to VEC may represent their best chance of successful outcome. Conversion to IUI offers the poorest outcome, and despite the potential for improvements in cycle protocol, abandoning and a further attempt does not improve outcome (using abandoned cycle as the denominator). Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Overwintering Stages of Meloidogyne incognita in Vitis vinifera.

PubMed

Melakeberhan, H; Ferris, H; McKenry, M V; Gaspard, J T

1989-01-01

The overwintering of Meloidogyne incognita in and around Vitis vinifera cv. French Colombard roots was studied in a naturally infested vineyard at the Kearney Agricultural Center, in a growth chamber, in inoculated vines in microplots at the University of California, Davis, and in a greenhouse. Infected roots were sampled at intervals from onset of vine dormancy until plants accumulated about 800 degree days (DD - base 10 C). Embryogenesis within eggs, classified as less than or more than 16 cells and fully differentiated, and numbers of juveniles (second to fourth stage) and preovipositional and mature (egg-laying) adult stages in roots were determined. All stages were present at the onset of dormancy. Juveniles and immature females were not recovered during the dormant period. Mature females and eggs were always present in roots, although the number of mature females generally decreased with time after onset of dormancy. In contrast, in a greenhouse experiment that accumulated comparable DD without the host plant going through dormancy, the number of mature females increased. After bud break, the number of eggs per female increased and all nematode stages were found in host roots. Eggs in all stages of embryogenesis were observed at all times of sampling, indicating that females overwinter and are capable of laying eggs when conditions improve in the spring and need to be considered in nematode management decisions.

Genetic parameters of egg defects and egg quality in layer chickens.

PubMed

Wolc, A; Arango, J; Settar, P; O'Sullivan, N P; Olori, V E; White, I M S; Hill, W G; Dekkers, J C M

2012-06-01

Genetic parameters were estimated for egg defects, egg production, and egg quality traits. Eggs from 11,738 purebred brown-egg laying hens were classified as salable or as having one of the following defects: bloody, broken, calcium deposit, dirty, double yolk, misshapen, pee-wee, shell-less, and soft shelled. Egg quality included albumen height, egg weight, yolk weight, and puncture score. Body weight, age at sexual maturity, and egg production were also recorded. Heritability estimates of liability to defects using a threshold animal model were less than 0.1 for bloody and dirty; between 0.1 and 0.2 for pee-wee, broken, misshapen, soft shelled, and shell-less; and above 0.2 for calcium deposit and double yolk. Quality and production traits were more heritable, with estimates ranging from 0.29 (puncture score) to 0.74 (egg weight). High-producing hens had a lower frequency of egg defects. High egg weight and BW were associated with an increased frequency of double yolks, and to a lesser extent, with more shell quality defects. Estimates of genetic correlations among defect traits that were related to shell quality were positive and moderate to strong (0.24-0.73), suggesting that these could be grouped into one category or selection could be based on the trait with the highest heritability or that is easiest to measure. Selection against defective eggs would be more efficient by including egg defect traits in the selection criterion, along with egg production rate of salable eggs and egg quality traits.

Host status of Meyer and Eureka lemons for Anastrepha ludens.

PubMed

Mangan, Robert L; Moreno, Aleena Tarshis

2012-04-01

Host status for Mexican fruit fly (Anastrepha ludens (Loew)) was examined under laboratory conditions in cage infested Eureka and Meyer lemons. Our approach was to allow females to oviposit on the two cultivars in separate laboratory cages with aluminum foil covering to restrict the areas where females had access to fruit surface. Fruit of each cultivar were placed in covered trays for incubations and at approximately weekly intervals, fruit were removed, dissected, and live and dead eggs and larvae tabulated in each tissue of the fruit. Infestation and survival were tabulated and analyzed for the effects of harvest date, fruit color and brix indices, postoviposition period, and cultivar. Infestation rate, determined by counts of total eggs and larvae was significantly higher in Meyer lemons. In both cultivars, females deposited eggs into both albedo and pulp tissue but not into flavedo. Both cultivars showed high resistance (> 90% mortality) to egg and first instars survival in albedo and pulp. Second and third instars surviving in the pulp had high survival rates (> 60%) in both cultivars in fruit dissected at weeks 2-4 after infestation. Total adults produced were slightly higher, and total second and third stage larvae were also higher for Meyer lemons. Numbers of adults and total second and third stage larvae increased in Eureka lemons in more mature fruit, but the higher numbers in Meyer lemons were not associated with fruit maturity, at time of infestation. Numbers of second and third stage larvae were significantly correlated with some fruit color indices in Eureka but not in Meyer lemons. Application of these results to quarantine risk analysis is discussed.

Mechanisms of lipid mobilization towards egg formation in broiler breeder hens using stable isotopes.

PubMed

Salas, C; Ekmay, R D; England, J A; Cerrate, S; Coon, C N

2017-02-01

The contribution of dietary, mobilized, or newly synthesized fatty acids in yolk formation at different periods of egg production was determined. In an initial experiment, a single dose of 13 C-linoleic acid was administered to pullets at the onset of egg production and their presence in follicles determined over the subsequent 10 days. In a second experiment, pullets were fed a daily 15 mg dose of U- 13 C-glucose beginning 2 wk prior to sexual maturity through the end of the experimental period. A 50 mg meal of U- 13 C-linoleic acid was orally administered approximately 10 d prior to sexual maturity (defined as first egg) representing body linoleic acid. Upon each hen's first egg, each bird received a 25 mg meal of 2 D 31 -linoleic acid representing dietary linoleic acid. All eggs were collected for the next 10 days. The incorporation of labeled linoleic acid and palmitic acid in egg yolk was then determined using GC-MS. This process was repeated at peak production and at 45 wk of age. At sexual maturity, the deposition of labeled palmitic acid in the yolk was higher compared with its deposition at peak production and 45 wk of age. The deposition of both 13 C- and 2 D 31 -linoleic acid increased with hen age. These results suggest that dietary and tissue linoleic acid is utilized to a greater extent in older hens and that lipogenesis (synthesis of palmitic acid) plays a larger role at sexual maturity in the young hen. © 2016 Poultry Science Association Inc.

Effect of climate region and stocking density on ostrich (Struthio camelus) productive performances.

PubMed

Bouyeh, M; Seidavi, A; Mohammadi, H; Sahoo, A; Laudadio, V; Tufarelli, V

2017-02-01

The effects of three climates (hot and dry, mild and humid and Alpine) and three flock densities (<100, 100-300 and >300 m 2 ) on ostrich reproductive and productive traits were studied. Data were compared with the benchmark target sets by the World Ostrich Association (Ostrich benchmark Performance Targets. Version 2, May, 2008) for reproductive qualifications of ostrich. No significant difference was observed on egg production, weight, fertility, hatchability and day-old chicks weight among the three climate conditions; however, the Alpine climate had a lower performance trend. Mild and humid climates had a significant effect of age at sexual maturity for both males and females as well as on the duration of egg production season. Stocking density did not show significant difference on egg production, hatchability, age of male and female at sexual maturity and on duration of egg production season, while an area >300 m 2 showed a reduction in egg weight and day-old chick weight. Further, an area <100 m 2 led to a weaker ostrich fertility rate. Results showed that the ostrich would have a better performance under hot and dry and mild and humid climates as compared to Alpine climate with a stocking density of 100-300 m 2 area per breeder bird. Thus, climatic intervention strategies at Alpine regions may be carried out for maintaining optimal reproductive qualification of ostrich so as to improve the productivity in this sector. © 2016 Blackwell Verlag GmbH.

TRPV3 channels mediate strontium-induced mouse egg activation

PubMed Central

Carvacho, Ingrid; Lee, Hoi Chang; Fissore, Rafael A.; Clapham, David E.

2014-01-01

SUMMARY In mammals, calcium influx is required for oocyte maturation and egg activation. The molecular identities of the calcium-permeant channels that underlie the initiation of embryonic development are not established. Here, we describe a Transient Receptor Potential (TRP) ion channel current activated by TRP agonists that is absent in TrpV3−/− eggs. TRPV3 current is differentially expressed during oocyte maturation, reaching a peak of maximum density and activity at metaphase of meiosis II (MII), the stage of fertilization. Selective activation of TRPV3 channels provokes egg activation by mediating massive calcium entry. Widely used to activate eggs, strontium application is known to yield normal offspring in combination with somatic cell nuclear transfer. We show that TRPV3 is required for strontium influx, as TrpV3−/− eggs failed to permeate Sr2+ or undergo strontium-induced activation. We propose that TRPV3 is the major mediator of calcium influx in mouse eggs and is a putative target for artificial egg activation. PMID:24316078

Seasonal Reproductive Biology of Drosophila suzukii (Diptera: Drosophilidae) in Temperate Climates.

PubMed

Grassi, Alberto; Gottardello, Angela; Dalton, Daniel T; Tait, Gabriella; Rendon, Dalila; Ioriatti, Claudio; Gibeaut, David; Rossi Stacconi, M Valerio; Walton, Vaughn M

2018-02-08

Drosophila suzukii (Matsumura; Diptera: Drosophilidae) is a key pest of sweet cherry and small fruits worldwide. The present studies were designed to describe the reproductive physiology in both sexes, through dissections of their reproductive organs. We extensively dissected female D. suzukii throughout the season from 2013 to 2016 and classified the reproductive status flies based on five recognizable ovarian maturation stages: 1) no ovaries; 2) unripe ovaries 3) ripening eggs in ovarioles; 4) mature eggs in ovarioles; and 5) mature eggs in the abdomen. Development was examined as a function of calendar days as well as degree-days (DD). Results obtained from winter collections revealed that females collected from November to March contained a lower percentage of mature eggs than females collected from April to September. These data suggest that environmental conditions during the dormant period induce reproductive diapause. Oogenesis likely increased with an increase in mean monthly temperatures and DD. The first overwintered females with mature eggs were dissected as early as 21 February 2014 in Trento (7 DD). Additionally, we found that a low proportion of males (less than 50%) had sperm in their testes between January and March, yet during the same period females already have sperm stored in their spermathecal. Ivy berries was an alternative but unfavorable non-crop host during the late dormant period, as evidenced by emergence of smaller adults when compared to individuals emerging from cherry fruits. This study showed that D. suzukii females have great potential for oviposition early in the season, posing a risk to early season maturing crop hosts. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Captive Rearing Program for Salmon River Chinook Salmon, 2002 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Venditti, David; Willard, Catherine; James, Chris

2003-11-01

During 2002, the Idaho Department of Fish and Game continued to develop techniques to rear Chinook salmon Oncorhynchus tshawytscha to sexual maturity in captivity and to monitor their reproductive performance under natural conditions. Eyed-eggs were hydraulically collected from redds in the East Fork Salmon River (EFSR; N = 328) and the West Fork Yankee Fork Salmon River (WFYF; N = 308) to establish brood year 2002 culture cohorts. The eyed-eggs were incubated and reared at the Eagle Fish Hatchery, Eagle, Idaho (Eagle). Juveniles collected in 2000 were PIT and elastomer tagged and vaccinated against vibrio Vibrio spp. and bacterial kidneymore » disease prior to being transferred to the NOAA Fisheries, Manchester Marine Experimental Station, Manchester, Washington (Manchester) for saltwater rearing through maturity. Smolt transfers included 203 individuals from the WFYF and 379 from the EFSR. Maturing fish transfers from Manchester to Eagle included 107 individuals from the LEM, 167 from the WFYF, and 82 from the EFSR. This was the second year maturing adults were held on chilled water at Eagle to test if water temperature manipulations could advance spawn timing. Adults from the LEM and WFYF were divided into chilled ({approx} 9 C) and ambient ({approx} 13.5 C) temperature groups while at Eagle. Forty-seven mature females from the LEM (19 chilled, 16 ambient, and 12 ambient not included in the temperature study) were spawned at Eagle with 42 males in 2002. Water temperature group was not shown to affect the spawn timing of these females, but males did mature earlier. Egg survival to the eyed stage averaged 66.5% and did not differ significantly between the temperature groups. Personnel from the Shoshone-Bannock Tribe placed a total of 47,977 eyed-eggs from these crosses in in-stream incubators. Mature adults (N = 215 including 56 precocial males) were released into the WFYF to evaluate their reproductive performance. After release, fish distributed themselves throughout the study section and displayed a progression of habitat associations and behavior consistent with progressing maturation and the onset of spawning. Twenty-six captive-reared females constructed 33 redds in the WFYF in 2002. Eighteen of these were hydraulically sampled, and eggs were collected from 17. The percentage of live eggs ranged from 0-100% and averaged 34.6%. No live eggs were found in redds spawned by brood year 1997 females. Expanding these results to the remaining redds gives an estimate of 22,900 eyed-eggs being produced by captive-reared fish in the WFYF. Additionally, 130 mature adults (including 41 precocial males) were released into the EFSR. Almost all of these fish moved out of the areas shoreline observers had access to, so no spawning behavior was observed. Radio-telemetry indicated that most of these fish initially moved downstream (although three females moved upstream as far as 7 km) and then held position.« less

Life History Attributes of Asian Carps in the Upper Mississippi River System

DTIC Science & Technology

2007-05-01

Mature ovary of a female silver carp. Each small white spherical structure is a mature egg 4 ERDC/TN ANSRP-07-1 May 2007 Silver carp in the...weight/fish weight), and fecundity (number of eggs per female ) of each silver and bighead carp were quantified. Diets of silver carp from the MMR also...through November, with gonads ranging from 1 to 13 percent of body weight. Females with mature ovaries (Figure 3) were present as early as age 2 years

Identification of a novel C1q family member in color crucian carp (Carassius auratus) ovary.

PubMed

Chen, Bo; Gui, Jianfang

2004-07-01

Potential roles of C1q/tumor necrosis factor (TNF) superfamily proteins have been observed in vertebrate oogenesis and oocyte maturation, but no ovary-specific member has been identified so far. In this study, we have cloned and identified a novel member of C1q family with a C1q domain in the C-terminal from fully grown oocyte cDNA library of color crucian carp and demonstrated that the gene might be specifically expressed in ovary and therefore designated as Carassius auratus ovary-specific C1q-like factor, CaOC1q-like factor. It encodes a 213 amino acid protein with a 17 amino acid signal peptide. There is only one protein band of about 24.5 kDa in the extracts from phase I to phase IV oocytes, but two positive protein bands are detected in the extracts of mature eggs and fertilized eggs. Furthermore, the mobility shift of the smaller target protein band cannot be eliminated by phosphatase treatment, but the larger protein band increases its mobility on the gel after phosphatase treatment, suggesting that the larger protein might be a phosphorylated form. Immunofluorescence localization indicates that the CaOC1q-like proteins localize in cytoplasm, cytoplasm membrane and egg envelope of the oocytes at cortical granule stage and vitellogenesis stage, whereas they were compressed to cytoplasm margin in ovulated mature eggs and discharged into perivitelline space between cytoplasm membrane and egg envelope after egg fertilization. Further studies on distribution and translocation mechanism of the CaOC1q-like factor will be benefit to elucidate the unique function in oogenesis, oocyte maturation and egg fertilization.

Exposure to tris(1,3-dichloro-2-propyl) phosphate for Two generations decreases fecundity of zebrafish at environmentally relevant concentrations.

PubMed

Zhang, Yongkang; Li, Meng; Li, Shuying; Wang, Qiangwei; Zhu, Guonian; Su, Guanyong; Letcher, Robert J; Liu, Chunsheng

2018-05-14

Previous studies reported that exposure to environmentally relevant concentrations of TDCIPP significantly decreased the number of cumulative eggs in zebrafish, but effects on the quantity of eggs and sperms remained unknown. Therefore, in this study, effects of TDCIPP on yolk diameter, surface morphology of eggs, sperm density and total motility were evaluated. First generation (F0) zebrafish larvae (Danio rerio) were exposed to 0, 50, 500 or 5000 ng/L tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) from 14 days post fertilization (dpf) to 120 dpf. The F0 generation of zebrafish were paired and F1 generation of embryos were collected and continuously exposed to the same concentrations of TDCIPP until 150 dpf. TDCIPP bioconcentration in the whole body as well as effects on survival and fecundity were evaluated in F1 generation. Exposure to TDCIPP resulted in an accumulation of the chemical and decreased survival of F1 generation of zebrafish. TDCIPP decreased cumulative production and changed surface morphology of eggs in females. In males, TDCIPP decreased total motility of sperm but did not affect sperm density. These effects on quality of egg and sperm might be responsible for the decreased hatching rates observed in cross mating experiments. Furthermore, TDCIPP exposure resulted in down-regulated gene expression related to gonadal development and maturation of germ cells in females or/and males, and the down-regulation was correlated to decreased fecundity. Taken together, the results suggested that exposure to TDCIPP could decrease the quantity of eggs and sperms by down-regulating the expression of genes related to gonadal development and maturation of germ cells in zebrafish. Copyright © 2018 Elsevier B.V. All rights reserved.

New insights into the amphibious life of Biomphalaria glabrata and susceptibility of its egg masses to fungal infection.

PubMed

Duarte, Glennyha F; Rodrigues, Juscelino; Fernandes, Éverton K K; Humber, Richard A; Luz, Christian

2015-02-01

The air-breathing snail Biomphalaria glabrata proliferates in stagnant freshwater, and nothing is known about the survival of eggs in intermittently (rather than perpetually) wet habitats. In the present study their egg masses matured, and juveniles subsequently eclosed and were mobile in a stable water film of transitory habitats simulated by two different simple test devices described here. The viability of eggs maintained in an unstable film however, was diminished. The maturation of egg masses in a water film or in water was significantly prevented by the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae. The efficiency depended on the fungal propagule and test environment. Hyphal bodies were more effective against egg masses than conidia. This appears to be a first report of activity of either entomopathogen against a mollusc. Both devices offer accurate and reproducible conditions to test both biological questions and the effects of substances or pathogens against B. glabrata egg masses in water films. Copyright © 2015 Elsevier Inc. All rights reserved.

When Isolated at Full Receptivity, in Vitro Fertilized Wheat (Triticum aestivum, L.) Egg Cells Reveal [Ca2+]cyt Oscillation of Intracellular Origin

PubMed Central

Pónya, Zsolt; Corsi, Ilaria; Hoffmann, Richárd; Kovács, Melinda; Dobosy, Anikó; Kovács, Attila Zoltán; Cresti, Mauro; Barnabás, Beáta

2014-01-01

During in vitro fertilization of wheat (Triticum aestivum, L.) in egg cells isolated at various developmental stages, changes in cytosolic free calcium ([Ca2+]cyt) were observed. The dynamics of [Ca2+]cyt elevation varied, reflecting the difference in the developmental stage of the eggs used. [Ca2+]cyt oscillation was exclusively observed in fertile, mature egg cells fused with the sperm cell. To determine how [Ca2+]cyt oscillation in mature egg cells is generated, egg cells were incubated in thapsigargin, which proved to be a specific inhibitor of the endoplasmic reticulum (ER) Ca2+-ATPase in wheat egg cells. In unfertilized egg cells, the addition of thapsigargin caused an abrupt transient increase in [Ca2+]cyt in the absence of extracellular Ca2+, suggesting that an influx pathway for Ca2+ is activated by thapsigargin. The [Ca2+]cyt oscillation seemed to require the filling of an intracellular calcium store for the onset of which, calcium influx through the plasma membrane appeared essential. This was demonstrated by omitting extracellular calcium from (or adding GdCl3 to) the fusion medium, which prevented [Ca2+]cyt oscillation in mature egg cells fused with the sperm. Combined, these data permit the hypothesis that the first sperm-induced transient increase in [Ca2+]cyt depletes an intracellular Ca2+ store, triggering an increase in plasma membrane Ca2+ permeability, and this enhanced Ca2+ influx results in [Ca2+]cyt oscillation. PMID:25535074

Reproductive Strategies of the Insidious Fish Ectoparasite, Neobenedenia sp. (Capsalidae: Monogenea)

PubMed Central

Dinh Hoai, Truong; Hutson, Kate S.

2014-01-01

Fish monogeneans are lethal parasites in aquaculture. We provide the first experimental evidence that a notorious fish monogenean, Neobenedenia sp., can produce viable eggs in isolation for three consecutive generations. We infected individual, isolated, farmed barramundi, Lates calcarifer (Bloch) with a single oncomiracidium (larva) of the hermaphroditic monogenean Neobenedenia sp. Isolated parasites reached sexual maturity at day 10 post-hatch (24°C, 35‰) and laid ∼3,300 embryonated eggs over 17 days. Egg production rapidly increased following sexually maturity on day 10 (58±15 eggs) and peaked on day 15 (496±68 eggs) before gradually decreasing. Neobenedenia sp. exhibited egg laying and egg hatching rhythms. Parasites laid eggs continuously, but egg production increased in periods of darkness (64.3%), while the majority of oncomiracidia (81%) emerged from eggs in the first three hours of light. Eggs laid by isolated ‘parent’ parasites hatched and individual emerging oncomiracidia were used to infect more individual, isolated fish, with three consecutive, isolated, parasite generations (F1, F2 and F3) raised in the laboratory. Infection success and egg hatching success did not differ between generations. Our data show that one parasite, in the absence of a mate, presents a severe threat to captive fish populations. PMID:25264931

Spatial Distribution of Megacopta cribraria (Hemiptera: Plataspidae) Adults, Eggs and Parasitism by Paratelenomus saccharalis (Hymenoptera: Platygastridae) in Soybean.

PubMed

Knight, Ian A; Roberts, Phillip M; Gardner, Wayne A; Oliver, Kerry M; Reay-Jones, Francis P F; Reisig, Dominic D; Toews, Michael D

2017-12-08

Since 2014, populations of the kudzu bug, Megacopta cribraria (F.) (Hemiptera: Plataspidae), have declined in the southeastern United States and seldom require treatment. This decline follows the discovery of Paratelenomus saccharalis (Dodd; Hymenoptera: Platygastridae), a non-native egg parasitoid. The objective of this project was to observe the temporal and spatial dynamics of P. saccharalis parasitism of kudzu bug egg masses in commercial soybean fields. Four fields were sampled weekly for kudzu bugs and egg masses at a density of one sample per 0.6 ha. Sampling commenced when soybean reached the R2 maturity stage and continued until no more egg masses were present. Responses including kudzu bugs, egg masses, and parasitism rates were analyzed using ANOVA, Spatial Analysis by Distance Indices (SADIE), and SaTScan spatial analysis software. Egg masses were collected from the field, held in the lab and monitored for emergence of kudzu bug nymphs or P. saccharalis. Kudzu bug populations were generally lower than previously reported in the literature and spatial aggregation was not consistently observed. Egg parasitism was first detected in early July and increased to nearly 40% in mid-August. Significant spatial patterns in parasitism were observed with spatio-temporal clusters being loosely associated with clusters of egg masses. There were no significant differences in parasitism rates between field margins and interiors, suggesting that P. saccharalis is an effective parasitoid of kudzu bug egg masses on a whole-field scale. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

On gonadic maturation and reproductive strategy in deep-sea benthic octopus Graneledone macrotyla

NASA Astrophysics Data System (ADS)

Guerra, Ángel; Sieiro, María Pilar; Roura, Álvaro; Portela, Julio M.; del Río, José Luís

2013-09-01

The new information reported in this paper is based on five maturing and mature females of the large-tuberculate octopus Graneledone macrotyla. These specimens were caught in bottom trawl surveys ATLANTIS 2009 (February 24 to April 1, 2009) and ATLANTIS 2010 (March 9 to April 5, 2010) carried out off the Argentinean Economic Exclusive Zone. Capture depth ranged from 475 to 921 m and sea bottom temperature between 2.8 and 3.1 °C. Development of the complex ovary, oviducts, and oviducal glands during gonadic maturation is described. The absence of spermathecae in the oviducal glands and the presence of fertilized eggs inside the ovary suggested that fertilization took place within the ovary. Histological techniques showed the presence of four types of oocytes. Maturing oocyte size-frequency distribution was polymodal. Fluorescence reaction showed that atresia occurred in both early and later oocyte maturation stages. Atresia affected 48-55 % of the initial number of oocytes. The maximum observed potential fecundity was estimated at 250-300 eggs. G. macrotyla showed a group-synchronous ovulation pattern, regulative atresia, and a batching spawning pattern with a few egg batches spawned intermittently over an extended period of spawning.

High Serum FSH is Associated with Brown Oocyte Formation and a Lower Pregnacy Rate in Human IVF Parctice.

PubMed

Xu, Hongyi; Deng, Kai; Luo, Qingbing; Chen, Juan; Zhang, Xin; Wang, Xiaoyan; Diao, Honglu; Zhang, Changjun

2016-01-01

To investigate whether brown zona pellucida (ZP) of oocytes affects the outcome of fertilization, embryo quality and pregnancy rate in in vitro fertilization-embryo transfer (IVF-ET). Based on the ZP color of their oocytes, a total number of 703 patients dated from 2012 to 2014 were divided into a normal egg group (group A) and a brown oocyte group (group B), with 629 and 74 cases, respectively. Clinical characteristics, gonadotropin (Gn) days, Gn dosage, serum hormone levels on the day of human chorionic gonadotropin (HCG) injection, ZP thickness (ZPT) of the eggs, fertilization rate, rescue intracytoplasmic sperm injection (rICSI) rate, good-quality embryo rate and pregnancy rate were compared between the two groups. No significant differences were found in the duration and the causes of infertility, and their basal level of endocrine hormone before IVF-ET between normal egg group and brown egg group. The level of serum hormone including estradiol, progesterone and luteinizing hormone on the day of HCG injection were again similar. Moreover, there were no differences in number of mature oocytes, oocyte fertilization rates and rICSI rates after IVF between the two groups. However, we observed that the ZPT of brown oocytes (group B) was higher than that of normal oocytes (group A). Moreover, the Gn dosage and FSH levels on the day of HCG injection were significantly higher in group B than in group A and the good-quality embryo rate and pregnancy rate in group B were lower than those in group A. Compared with normal eggs, oocytes with a brown ZP were found to have a higher ZPT, lower embryo quality and lower pregnancy rate, which might be due to a high Gn dosage injection and high serum FSH levels during IVT-ET cycles. © 2016 The Author(s) Published by S. Karger AG, Basel.

[Reproductive behavior of Opistognathus rosenblatti (Perciformes: Opistognathidae) in captivity].

PubMed

Contreras, Mauricio; Anguas, Benjamín; González, Pedro G; Martínez, Rodolfo E

2012-09-01

The Blue Spotted Jawfish O. rosenblatti, is an endemic species from the Gulf of California, included in the local list of protected species. With few biological reports, this species is appreciated in the aquarium industry due to its coloration and digging behaviour, and has a considerable value. With the aim to generate valuable biological information, eight fishes were caught at Loreto Natural Marine Protected Area. Captured fishes were juveniles, and just three of them were kept in an aquarium conditioned with gravel, pieces of shells and coral as substrata. Temperature and photoperiod conditions were stable, and they were supplied with a variety of live and inert feeds. Fishes reached maturity in eight months, according to literature reports, displaying mature male courtship coloration and upward movements in the water column. Fishes spawned several times over more than two years in captivity. Presences of egg masses, or some evidence of egg shell or larvae, were registered in 50 occasions. Male took care of eggs in his shelter, but never in his mouth. Egg masses had an average of 3 592 eggs, with a hatching rate close to 99%. Eggs were apparently rounded having three diameter measurements with significant differences (1.17mm mean higher diameter, SD=0.054; 1.13mm mean lower diameter, 0.058; 0.99mm mean height, 0.045; n=125). Most of corion eggs had four, rarely six filaments; with a single oil drop (0.30mm mean diameter, 0.021, n=59). Incubation lasted 10.4 days (9-14), depending on water temperature (21.0-25.3 degrees C). Egg hatching occurred after darkness, emerging newly hatched larvae of 4.51mm mean notochord length (0.082, n=30), with reserves exhausted, eyes pigmented and mouth opened, ready to eat. This study represents the first report on this species courtship displaying, spawning and some basic characteristics of eggs masses and larvae in captivity. Also, their flexibility and adaptability of individual behaviour to particular environment conditions, lead to consider worth their commercial culture, as already occur with other species of this family.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santella, Luigia, E-mail: santella@szn.it; Limatola, Nunzia; Chun, Jong T.

The interaction of the spermatozoon with the egg at fertilization remains one of the most fascinating mysteries of life. Much of our scientific knowledge on fertilization comes from studies on sea urchin and starfish, which provide plenty of gametes. Large and transparent, these eggs have served as excellent model systems for studying egg activation and embryo development in seawater, a plain natural medium. Starfish oocytes allow the study of the cortical, cytoplasmic and nuclear changes during the meiotic maturation process, which can also be triggered in vitro by hormonal stimulation. These morphological and biochemical changes ensure successful fertilization of the eggsmore » at the first metaphase. On the other hand, sea urchin eggs are fertilized after the completion of meiosis, and are particularly suitable for the study of sperm–egg interaction, early events of egg activation, and embryonic development, as a large number of mature eggs can be fertilized synchronously. Starfish and sea urchin eggs undergo abrupt changes in the cytoskeleton and ion fluxes in response to the fertilizing spermatozoon. The plasma membrane and cortex of an egg thus represent “excitable media” that quickly respond to the stimulus with the Ca{sup 2+} swings and structural changes. In this article, we review some of the key findings on the rapid dynamic rearrangements of the actin cytoskeleton in the oocyte/egg cortex upon hormonal or sperm stimulation and their roles in the modulation of the Ca{sup 2+} signals and in the control of monospermic fertilization. - Highlights: • Besides microtubules, microfilaments may anchor the nucleus to oocyte surface. • The cortical Ca{sup 2+} flash and wave at fertilization mirror electrical membrane change. • Artificial egg activation lacks microvilli extension in the perivitelline space. • Calcium is necessary but not sufficient for cortical granules exocytosis. • Actin cytoskeleton modulates Ca{sup 2+} release at oocyte maturation and fertilization.« less

The growth and development of Schistosoma mansoni in mice exposed to sublethal doses of radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aitken, R.; Wilson, R.A.

1989-12-01

The maturation of Schistosoma mansoni was studied in mice exposed to various sublethal doses of radiation. Although the treatment of mice with 500 rads of radiation prior to infection did not alter parasite maturation, doses in excess of 500 rads led to a reduction in worm burden. This could not be attributed to a delay in the arrival of parasites in the hepatic portal system. Worms developing in mice treated with 800 rads commenced egg-laying about 1 wk later than worms in intact mice, and the rate of egg deposition appeared to be lower in irradiated hosts. The data demonstratemore » that exposure of C57BL/6 mice to doses of radiation in excess of 500 rads impairs their ability to carry infections of S. mansoni. The findings do not support the hypothesis that primary worm burdens in the mouse are controlled by a host immune response.« less

Reproductive biology of the brown tree snake, Boiga irregularis (Reptilia: Colubridae), during colonization of Guam and comparison with that in their native range

USGS Publications Warehouse

Savidge, J.A.; Qualls, F.J.; Rodda, G.H.

2007-01-01

Since their introduction to Guam shortly after World War II, brown tree snakes, Boiga irregularis (Merrem), have seriously impacted the biota and human population of the island. Understanding the biology of this exotic species will likely be important to the success of control programs. We compared the reproductive biology of 782 B. irregularis caught on Guam during the 1980s with results from published studies of native-range populations. Average and maximum sizes of mature snakes on Guam were larger than those from Australian populations. The majority of female brown tree snakes matured at snoutvent lengths (SVLs) of 910-1,025 mm, and most males matured at SVLs of 940-1,030 mm. on Guam. Based on growth rates from the early 1990s on Guam, sexual maturity is estimated to occur during a snake's third or fourth year. Only one female (0.3%) in our data set had oviductal eggs. Clutch size was estimated at 4.3 (SD = 2.2), based on large vitellogenic ovarian follicle (???30 mm in length) and oviductal egg counts. Unlike their Australian counterparts, the Guam population reproduced year-round. Our data offer insights into the likely reproductive patterns of brown tree snakes should they infest other islands in the Pacific region. ?? 2007 by University of Hawai'i Press. All rights reserved.

Near infrared spectrometers determine stage maturity in channel catfish

USDA-ARS?s Scientific Manuscript database

Maturation is not synchronized in channel catfish and hence, individual fish are frequently handled and manually stage for maturation based on a selective subjective method. Fully matured fish are more responsive to hormone-induced spawning, and often result in better egg quality, higher relative f...

Downregulation of surface sodium pumps by endocytosis during meiotic maturation of Xenopus laevis oocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmalzing, G.; Eckard, P.; Kroener, S.P.

1990-01-01

During meiotic maturation, plasma membranes of Xenopus laevis oocytes completely lose the capacity to transport Na and K and to bind ouabain. To explore whether the downregulation might be due to an internalization of the sodium pump molecules, the intracellular binding of ouabain was determined. Selective permeabilization of the plasma membrane of mature oocytes (eggs) by digitonin almost failed to disclose ouabain binding sites. However, when the eggs were additionally treated with 0.02% sodium dodecyl sulfate (SDS) to permeabilize inner membranes, all sodium pumps present before maturation were recovered. Phosphorylation by (gamma-32P)ATP combined with SDS-polyacrylamide gel electrophoresis (PAGE) and autoradiographymore » showed that sodium pumps were greatly reduced in isolated plasma membranes of eggs. According to sucrose gradient fractionation, maturation induced a shift of sodium pumps from the plasma membrane fraction to membranes of lower buoyant density with a protein composition different from that of the plasma membrane. Endocytosed sodium pumps identified on the sucrose gradient from (3H)ouabain bound to the cell surface before maturation could be phosphorylated with inorganic (32P)phosphate. The findings suggest that downregulation of sodium pumps during maturation is brought about by translocation of surface sodium pumps to an intracellular compartment, presumably endosomes. This contrasts the mechanism of downregulation of Na-dependent cotransport systems, the activities of which are reduced as a consequence of a maturation-induced depolarization of the membrane without a removal of the corresponding transporter from the plasma membrane.« less

Fish as vectors in the dispersal of Bythotrephes cederstroemi: Diapausing eggs survive passage through the gut

USGS Publications Warehouse

Jarnagin, S.T.; Swan, B.K.; Kerfoot, W.C.

2000-01-01

1. Bythotrephes cederstroemi (Crustacea: Onychopoda: Cercopagidae) is an introduced invertebrate predator currently spreading through the Laurentian Great Lakes region of North America. We examined a previously unsuspected way in which B. cederstroemi may be dispersed by fish by their consumption of diapausing eggs. 2. Ninety-four percentage of the mature B. cederstroemi diapausing eggs consumed by fish were egested apparently intact. This proportion is considerably above previous estimates for the ephippial eggs of Daphnia. The hatching success of diapausing eggs was compared among four categories: (a) eggs released naturally by B. cederstroemi (control, 73% hatched (b) eggs released during 'stressful confinement' (46% hatched) (c) eggs dissected from dead females (13% hatched) and (d) eggs recovered from faecal pellets following consumption by fish (viable gut passage experiment, 41% hatched). 3. Samples of small fish and B. cederstroemi were collected simultaneously. Examination of gut contents revealed that fish contained B. cederstroemi diapausing eggs and that B. cederstroemi bearing resting eggs were consumed selectively over those without eggs. Moreover, fish selected B. cederstroemi bearing mature rather than immature diapausing eggs. 4. The fact that diapausing eggs survive gut passage is important for the dispersal of B. cederstroemi. Fish often move between the pelagic and littoral zones of lakes and may thus disperse diapausing eggs widely. Fish may also move between lakes connected by river systems and can be caught and passively dispersed by anglers or piscivorous birds. Our results demonstrate the potential for fish to act as vectors in the spread of B. cederstroemi.

The Acp26Aa seminal fluid protein is a modulator of early egg hatchability in Drosophila melanogaster.

PubMed

Chapman, T; Herndon, L A; Heifetz, Y; Partridge, L; Wolfner, M F

2001-08-22

Drosophila melanogaster male accessory gland proteins (Acps) that are transferred in the ejaculate with sperm mediate post-mating competition for fertilizations between males. The actions of Acps include effects on oviposition and ovulation, receptivity and sperm storage. Two Acps that modulate egg production are Acp26Aa (ovulin) and Acp70A (the sex peptide). Acp26Aa acts specifically on the process of ovulation (the release of mature eggs from the ovaries), which is initiated 1.5 h after mating. In contrast, sperm storage can take as long as 6-9 h to complete. Initial ovulations after matings by virgin females will therefore occur before all sperm are fully stored and the extra eggs initially laid as a result of Acp26Aa transfer are expected to be inefficiently fertilized. Acp26Aa-mediated release of existing eggs should not cause a significant energetic cost or lead to a decrease in female lifespan assuming, as seems likely, that the energetic cost of egg laying comes from de novo egg synthesis (oogenesis) rather than from ovulation. We tested these predictions using Acp26Aa(1) mutant males that lack Acp26Aa but are normal for other Acps and Acp26Aa(2) males that transfer a truncated but fully functional Acp26Aa protein. Females mating with Acp26Aa(2) (truncation) males that received functional Acp26Aa produced significantly more eggs following their first matings than did mates of Acp26Aa(1) (null) males. However, as predicted above, these extra eggs, which were laid as a result of Acp26Aa transfer to virgin females, showed significantly lower egg hatchability. Control experiments indicated that this lower hatchability was due to lower rates of fertilization at early post-mating times. There was no drop in egg hatchability in subsequent non-virgin matings. In addition, as predicted above, females that did or did not receive Acp26Aa did not differ in survival, lifetime fecundity or lifetime progeny, indicating that Acp26Aa transfer does not represent a significant energetic cost for females and does not contribute to the survival cost of mating. Acp26Aa appears to remove a block to oogenesis by causing the clearing out of existing mature eggs and, thus, indirectly allowing oogenesis to be initiated immediately after mating. The results show that subtle processes coordinate the stimulation of egg production and sperm storage in mating pairs.

Evaluation of methods to estimate lake herring spawner abundance in Lake Superior

USGS Publications Warehouse

Yule, D.L.; Stockwell, J.D.; Cholwek, G.A.; Evrard, L.M.; Schram, S.; Seider, M.; Symbal, M.

2006-01-01

Historically, commercial fishers harvested Lake Superior lake herring Coregonus artedi for their flesh, but recently operators have targeted lake herring for roe. Because no surveys have estimated spawning female abundance, direct estimates of fishing mortality are lacking. The primary objective of this study was to determine the feasibility of using acoustic techniques in combination with midwater trawling to estimate spawning female lake herring densities in a Lake Superior statistical grid (i.e., a 10′ latitude × 10′ longitude area over which annual commercial harvest statistics are compiled). Midwater trawling showed that mature female lake herring were largely pelagic during the night in late November, accounting for 94.5% of all fish caught exceeding 250 mm total length. When calculating acoustic estimates of mature female lake herring, we excluded backscattering from smaller pelagic fishes like immature lake herring and rainbow smelt Osmerus mordax by applying an empirically derived threshold of −35.6 dB. We estimated the average density of mature females in statistical grid 1409 at 13.3 fish/ha and the total number of spawning females at 227,600 (95% confidence interval = 172,500–282,700). Using information on mature female densities, size structure, and fecundity, we estimate that females deposited 3.027 billion (109) eggs in grid 1409 (95% confidence interval = 2.356–3.778 billion). The relative estimation error of the mature female density estimate derived using a geostatistical model—based approach was low (12.3%), suggesting that the employed method was robust. Fishing mortality rates of all mature females and their eggs were estimated at 2.3% and 3.8%, respectively. The techniques described for enumerating spawning female lake herring could be used to develop a more accurate stock–recruitment model for Lake Superior lake herring.

Eggshell and Histology Provide Insight on the Life History of a Pterosaur with Two Functional Ovaries.

PubMed

Wang, Xiaolin; Kellner, Alexander W A; Cheng, Xin; Jiang, Shunxing; Wang, Qiang; Sayão, Juliana M; Rodrigues, Taissa; Costa, Fabiana R; Li, Ning; Meng, X I; Zhou, Zhonghe

2015-09-01

The counterpart of a previously described non-pterodactyloid pterosaur with an egg revealed the presence of a second egg inside the body cavity of this gravid female. It clearly shows that pterosaurs had two functional oviducts and demonstrates that the reduction of one oviduct was not a prerequisite for developing powered flight, at least in this group. Compositional analysis of one egg suggests the lack of a hard external layer of calcium carbonate. Histological sections of one femur lack medullary bone and further demonstrate that this pterosaur reached reproductive maturity before skeletal maturity. This study shows that pterosaurs laid eggs even smaller than previously thought and had a reproductive strategy more similar to basal reptiles than to birds. Whether pterosaurs were highly precocial or needed parental care is still open to debate.

Adult pollen diet essential for egg maturation by a solitary osmia bee

USDA-ARS?s Scientific Manuscript database

Reproduction is a nutritionally costly activity for many insects, as their eggs are rich in lipids and proteins. Non-social bees lay especially large eggs. Adult female bees visit flowers to collect pollen and nectar, or sometimes oils, to feed their progeny. For adult bees, benefits of pollen feedi...

Reproduction of the giant jellyfish, Nemopilema nomurai (Scyphozoa: Rhizostomeae), in 2006-2008 as peripherally-transported populations

NASA Astrophysics Data System (ADS)

Iguchi, Naoki; Lee, Hye Eun; Yoon, Won Duk; Kim, Suam

2010-06-01

This study investigated the sexual maturation process, release of spermatozoa or eggs and oocyte diameter of the rhizostomid medusae Nemopilema nomurai using samples collected from August 2006 to June 2008 from the waters around Korea and Japan, including peripheral areas outside the species’ usual habitat. Immature medusae were observed from June to October only in the western sector of the study area. The onset of spermatozoa and egg release occurred in September and October, respectively, and peaked in December and January. Medusae migrated eastward from source areas with the Tsushima Warm Current, where they formed gametes and spawned. Peak position and maximum oocyte diameter increased as the gonads developed according to the size-frequency distribution of oocytes. No fertilized eggs or embryos were found in the gonads. The correlation was analyzed with bell diameter, maximum oocyte diameter, sampling date, surface water temperature and gonad color to estimate which environmental factors and maturation indices were related to the maturation stage of females. Maturation stage correlated well with maximum oocyte diameter, which correlated negatively with surface water temperature. There was no significant correlation between bell diameter and maturation stage. Therefore, bell diameter was inappropriate for determining maturation index. Sex could not be distinguished clearly by gonad color. However, light pink gonads were more prevalent in males and various deep colors such as orange and brown were more frequent in female medusae.

Response of broiler breeder females to feed restriction below recommended levels. 1. Growth and reproductive performance.

PubMed

Fattori, T R; Wilson, H R; Harms, R H; Miles, R D

1991-01-01

Arbor Acre broiler breeders were used to determine the effects on growth and reproductive performance of quantitative feed restriction below breeder recommended levels. Feed treatments were: 8% above standard (+8%); standard feeding program (STD); and 8 (-8%), 16 (-16%), and 24% (-24%) below standard. Proportional decreases in feed allocation resulted in corresponding decreases in body weight, frequency of double-yolked eggs, and number of days in production. Egg weight, fertility, hatchability, and female mortality to 64 wk of age were not significantly (P greater than or equal to .05) affected by the reduction in feed intake. Shell quality was significantly improved with the -16 and -24% feed treatments. A delay in sexual maturity caused a significant (P less than or equal to .05) decrease in average rate of lay (%hen-day) but not in total settable eggs for treatments -16 and -24% to 64 wk of age.

Calcium and actin in the saga of awakening oocytes.

PubMed

Santella, Luigia; Limatola, Nunzia; Chun, Jong T

2015-04-24

The interaction of the spermatozoon with the egg at fertilization remains one of the most fascinating mysteries of life. Much of our scientific knowledge on fertilization comes from studies on sea urchin and starfish, which provide plenty of gametes. Large and transparent, these eggs have served as excellent model systems for studying egg activation and embryo development in seawater, a plain natural medium. Starfish oocytes allow the study of the cortical, cytoplasmic and nuclear changes during the meiotic maturation process, which can also be triggered in vitro by hormonal stimulation. These morphological and biochemical changes ensure successful fertilization of the eggs at the first metaphase. On the other hand, sea urchin eggs are fertilized after the completion of meiosis, and are particularly suitable for the study of sperm-egg interaction, early events of egg activation, and embryonic development, as a large number of mature eggs can be fertilized synchronously. Starfish and sea urchin eggs undergo abrupt changes in the cytoskeleton and ion fluxes in response to the fertilizing spermatozoon. The plasma membrane and cortex of an egg thus represent "excitable media" that quickly respond to the stimulus with the Ca(2+) swings and structural changes. In this article, we review some of the key findings on the rapid dynamic rearrangements of the actin cytoskeleton in the oocyte/egg cortex upon hormonal or sperm stimulation and their roles in the modulation of the Ca(2+) signals and in the control of monospermic fertilization. Copyright © 2015 Elsevier Inc. All rights reserved.

When to care for, abandon, or eat your offspring: the evolution of parental care and filial cannibalism.

PubMed

Klug, Hope; Bonsall, Michael B

2007-12-01

Parental care and filial cannibalism (the consumption of one's own offspring) co-occur in many animals. While parental care typically increases offspring survival, filial cannibalism involves the killing of one's young. Using an evolutionary ecology approach, we evaluate the importance of a range of factors on the evolution of parental care and filial cannibalism. Parental care, no care/total abandonment, and filial cannibalism evolved and often coexisted over a range of parameter space. While no single benefit was essential for the evolution of filial cannibalism, benefits associated with adult or offspring survival and/or reproduction facilitated the evolution of cannibalism. Our model highlights the plausibility of a range of alternative hypotheses. Specifically, the evolution of filial cannibalism was enhanced if (1) parents could selectively cannibalize lower-quality offspring, (2) filial cannibalism increased egg maturation rate, (3) energetic benefits of eggs existed, or (4) cannibalism increased a parent's reproductive rate (e.g., through mate attractiveness). Density-dependent egg survivorship alone did not favor the evolution of cannibalism. However, when egg survival was density dependent, filial cannibalism invaded more often when the density dependence was relatively more intense. Our results suggest that population-level resource competition potentially plays an important role in the evolution of both parental care and filial cannibalism.

The chemosensitivity of labellar sugar receptor in female Phormia regina is paralleled with ovary maturation: Effects of serotonin.

PubMed

Solari, Paolo; Stoffolano, John G; De Rose, Francescaelena; Barbarossa, Iole Tomassini; Liscia, Anna

2015-11-01

Oogenesis in most adult insects is a nutrient-dependent process involving ingestion of both proteins and carbohydrates that ultimately depends on peripheral input from chemoreceptors. The main goal of this study was to characterize, in the female blowfly Phormia regina, the responsive changes of the labellar chemoreceptors to carbohydrates and proteins in relation to four different stages along the ovarian cycle: (1) immature ovaries, (2) mid-mature ovaries, (3) mature ovaries and ready for egg-laying and (4) post egg-laying ovaries. Then, the possible effects exerted by exogenous serotonin on the chemoreceptor sensitivity profiles were investigated. Our results show that ovary length, width and contraction rate progressively increase from stage 1 to 3, when all these parameters reach their maximum values, before declining in the next stage 4. The sensitivity of the labellar "sugar" chemoreceptors to both sucrose and proteins varies during the ovarian maturation stages, reaching a minimum for sucrose in stage 3, while that to proteins begins. Exogenous 5-HT supply specifically increases the chemoreceptor sensitivity to sugar at the stages 3 and 4, while it does not affect that to proteins. In conclusion, our results provide evidence that in female blowflies the cyclic variations in the sensitivity of the labellar chemosensilla to sugars and proteins are time-related to ovarian development and that during the stages 3 and 4 the responsiveness of the sugar cell to sucrose is under serotonergic control. Copyright © 2015 Elsevier Ltd. All rights reserved.

New insights into the amphibious life of Biomphalaria glabrata and susceptibility of its egg masses to fungal infection

USDA-ARS?s Scientific Manuscript database

Egg masses of an aquatic snail, Biomphalaria glabrata, matured, and juveniles subsequently eclosed and were mobile in a stable water film of transitory habitats simulated by two different simple test devices described here. The viability of eggs maintained in an unstable film due to low ambient mois...

Cytoplasmic regionalization in starfish oocyte occurrence and localization of cytoplasmic determinants responsible for the formation of archenteron and primary mesenchyme in starfish ( asterias amurensis) oocytes

NASA Astrophysics Data System (ADS)

Zhang, Shicui; Wu, Xianhan; Zhou, Jing; Wang, Renxue; Wu, Shangqin

1990-09-01

Starfish oocytes with intact germinal vesicles (GVs) were cut along desired planes with glass needles or ligated using silk thread loops into two parts and allowed to mature in vitro, and inseminated. The experimental results showed that (1) only the parts with GVs or partial GV contents (PGVCs) cleaved, those without any GV materials did not; but nucleated and non-nucleated fragments cut from mature eggs were able to divide; (2) the development of animal parts of oocytes containing GVs or PGVCs was like that of animal fragments of matured oocytes with female pronuclei; most of them gave rise to permanent blastulae, and just a few formed ectodermal vesicles with a little primary mesenchyme; (3) a large part of vegetal fragments with GVs or PGVCs, and the vegetal parts of mature eggs without female pronuclei developed into small but normal embryos; (4) the fragments containing GVs or PGVCs obtained from the oocytes along a plane parallel to the animal-vegetal (A-V) axis developed as normally as the halves (with or without female pronuclei) severed from mature eggs along the same axis. Based on the data above, it was concluded that (1) the non-chromatin materials in the oocyte GVs are indispensable for successful fertilization and cleavage of starfish eggs; (2) some factor (s) located asymmetrically in the vegetal hemispheres of starfish oocytes is (are) responsible for formation of the archenteron and primary mesenchyme. It is evident from the above findings that the oocyte cytoplasm of the starfish had already regionalized before the GV break-down.

Maturation and fecundity of a stock-enhanced population of striped bass in the Savannah River Estuary, U.S.A.

USGS Publications Warehouse

Will, T.A.; Reinert, T.R.; Jennings, C.A.

2002-01-01

The striped bass Morone saxatilis population in the Savannah River (south-eastern U.S.A.) collapsed in the 1980s, and recent efforts to restore the population have resulted in increased catch-per-unit-effort (CPUE) of striped bass in the Savannah River Estuary (SRE). The abundance of eggs and larvae, however, remain well below historic levels. The primary cause of the population decline was remedied, and environmental conditions seem suitable for striped bass spawning. Regression analysis of data derived from ultrasonic imaging of 31 striped bass resulted in a statistical model that predicted ovary volume well (r2=0.95). The enumeration of oocytes from ovarian tissue samples and the prediction of ovary volume allowed fecundity to be estimated without sacrificing the fish. Oocyte maturation in Savannah River striped bass seemed to progress normally, with oocytes developing to final stages of maturity in larger fish (>750 mm LT). Additionally, fecundity estimates were comparable to a neighbouring striped bass population. The environmental cues needed to trigger development and release of striped bass oocytes into the SRE appeared to be present. If most of the striped bass females in the SRE are still young (<7 years), the ability to produce large numbers of eggs will be limited. As these young fish mature, egg production probably will increase and the density of striped bass eggs eventually will approach historic levels, provided suitable habitat and water quality are maintained. ?? 2002 The Fisheries Society of the British Isles.

Dynamic distribution of spindlin in nucleoli, nucleoplasm and spindle from primary oocytes to mature eggs and its critical function for oocyte-to-embryo transition in gibel carp.

PubMed

Sun, Min; Li, Zhi; Gui, Jian-Fang

2010-10-01

Spindlin (Spin) was thought as a maternal-effect factor associated with meiotic spindle. Its role for the oocyte-to-embryo transition was suggested in mouse, but its direct evidence for the function had been not obtained in other vertebrates. In this study, we used the CagSpin-specific antibody to investigate CagSpin expression pattern and distribution during oogenesis of gibel carp (Carassius auratus gibelio). First, the oocyte-specific expression pattern and dynamic distribution was revealed in nucleoli, nucleoplasm, and spindle from primary oocytes to mature eggs by immunofluorescence localization. In primary oocytes and growth stage oocytes, CagSpin accumulates in nucleoli in increasing numbers along with the oocyte growth, and its disassembly occurs in vitellogenic oocytes, which implicates that CagSpin may be a major component of a large number of nucleoli in fish growth oocytes. Then, co-localization of CagSpin and β-tubulin was revealed in meiotic spindle of mature egg, indicating that CagSpin is one spindle-associated factor. Moreover, microinjection of CagSpin-specific antibody into the fertilized eggs blocked the first cleavage, and found that the CagSpin depletion resulted in spindle assembly disturbance. Thereby, our study provided the first direct evidence for the critical oocyte-to-embryo transition function of Spin in vertebrates, and confirmed that Spin is one important maternal-effect factor that participates in oocyte growth, oocyte maturation, and oocyte-to-embryo transition.

Attempted surgical correction of single- and multiyear post-ovulatory egg stasis in yellow and red Irish lords, Hemilepidotus jordani (Bean) and Hemilepidotus hemilepidotus (Tilesius)

USGS Publications Warehouse

Goertz, C.E.C.; Mulcahy, Daniel M.

2011-01-01

Egg stasis ('egg-binding', 'post-ovulatory stasis') is a poorly characterized syndrome characterized by an inability of female fish to complete ovulation and to naturally expel mature eggs. Although it occurs in a variety of fish species, no definitive studies of the causation, prevalence, prevention and treatment have been done. The cause of egg stasis appears to be multifactorial to include aspects of a captive environment not suitable for the completion of spawning.

Parthenogenetic embryos from unfertilized Chinese painted quail eggs alter albumen pH, gases, and ion concentrations during incubation.

PubMed

Santa Rosa, P; Parker, H M; Kiess, A S; McDaniel, C D

2016-01-15

Parthenogenesis is a form of embryonic development that occurs without fertilization. Recently, parthenogenesis has been reported in Chinese painted quail eggs. In Japanese quail, it has been shown that albumen pH of incubated fertile eggs is lower than that of incubated infertile eggs. However, it is unknown if alterations, similar to those in incubated fertile eggs, occur in albumen pH, gases, or ion concentrations from unfertilized eggs exhibiting parthenogenetic development. Therefore, the objective of this study was to determine if any differences in pH, gases, or ion concentrations exist between incubated unfertilized eggs exhibiting parthenogenetic development versus unfertilized eggs with no development over incubation. In this study, eggs were collected daily from Chinese painted quail hens that were separated from males at 4 weeks of age, before sexual maturity. Eggs were stored for 0 to 3 days at 20 °C and incubated at 37.5 °C for 12 days. Eggs were weighed before and after incubation to obtain percentage egg weight loss. After incubation, embryo size and albumen O2, CO2, Ca(2+), Na(+), and Cl(-) concentrations as well as pH were obtained from each incubated egg. Over incubation, albumen from unfertilized eggs exhibiting parthenogenetic development had a lower pH as well as less O2 and Cl(-), yet a higher Ca(2+) and Na(+) concentration as compared with the albumen of unfertilized eggs with no development. Also, eggs exhibiting parthenogenetic development had a higher albumen CO2 concentration as compared with eggs without development. The rate of egg weight loss was much lower in eggs exhibiting parthenogenetic development as compared with eggs without development. Also, as parthenogen size increased, there was a decrease in albumen pH, O2, and Cl(-), yet an increase in CO2 and Ca(2+). In conclusion, it appears that, over incubation, parthenogenetic development from unfertilized eggs alters the composition of albumen as compared with the albumen from unfertilized eggs with no parthenogenetic development. Published by Elsevier Inc.

Maturation of Shark Single-Domain (IgNAR) Antibodies: Evidence for Induced-Fit Binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanfield, R.L.; Dooley, H.; Verdino, P.

2007-07-13

Sharks express an unusual heavy-chain isotype called IgNAR, whose variable regions bind antigen as independent soluble domains. To further probe affinity maturation of the IgNAR response, we structurally characterized the germline and somatically matured versions of a type II variable (V) region, both in the presence and absence of its antigen, hen egg-white lysozyme. Despite a disulfide bond linking complementarity determining regions (CDRs) 1 and 3, both germline and somatically matured V regions displayed significant structural changes in these CDRs upon complex formation with antigen. Somatic mutations in the IgNAR V region serve to increase the number of contacts withmore » antigen, as reflected by a tenfold increase in affinity, and one of these mutations appears to stabilize the CDR3 region. In addition, a residue in the HV4 loop plays an important role in antibody-antigen interaction, consistent with the high rate of somatic mutations in this non-CDR loop.« less

The reproduction of lake trout in southern Lake Superior

USGS Publications Warehouse

Eschmeyer, Paul H.

1955-01-01

Thirteen fish identified by commercial fishermen as siscowets (Salvelinus namaycush siscowet) also showed extensive individual variation in numbers of eggs, although egg production tended to increase with increasing length and weight of the fish. A mature female siscowet as small as 16.5 inches long and a 15.7-inch mature male were collected about 45 miles north of Grand Marais, Michigan. Combined data from all collections showed that spawning of lake trout or siscowets may occur during at least 6 months of the year (June to November).

The effect of the addition of cow brain powder in commercial feed on the gonadal maturity of comet goldfish (Carassius auratus auratus)

NASA Astrophysics Data System (ADS)

Andriani, Y.; Subhan, U.; Rosidah; Iskandar; Zidni, I.; Abdillah, A. M.

2018-04-01

The aim of this research was to analysis the effect of addition bovine’s brain meal in artificial feed on gonad maturity and to find out the best time of gonad maturity in comet fish.This research was conducted at Fourth Building Hatchery Faculty of Fisheries and Marine Sciences Padjadjaran University on November 2014 until Januari 2015. Freeze drying of bovine brain was conducted at Research Center Inter University Bandung Institute of Technology. The research was using Completely Randomized Design (CRD) with four treatments and three replications.The treatment were 20 mg/kg, 35 mg/kg, 50mg/kg and control. The parameters of this research are Gonado Somatic Index (GSI) and egg maturity level. Addition of bovine brain meal in feed with the dose of 50 mg/kg are giving the best result until 45 days of the care time against gonad maturity of comet fish with GSI result 12.93 %, egg maturity level ripe phase 21.115 and fecundity 1520 grain/g.

Transfer of intracolonial genetic variability through gametes in Acropora hyacinthus corals

NASA Astrophysics Data System (ADS)

Schweinsberg, M.; González Pech, R. A.; Tollrian, R.; Lampert, K. P.

2014-03-01

In recent years, the new phenomenon of intracolonial genetic variability within a single coral colony has been described. This connotes that coral colonies do not necessarily consist of only a single genotype, but may contain several distinct genotypes. Harboring more than one genotype could improve survival under stressful environmental conditions, e.g., climate change. However, so far it remained unclear whether the intracolonial genetic variability of the adult coral is also present in the gametes. We investigated the occurrence of intracolonial genetic variability in 14 mature colonies of the coral Acropora hyacinthus using eight microsatellite loci. A grid was placed over each colony before spawning, and the emerging egg/sperm bundles were collected separately in each grid. The underlying tissues as well as the egg/sperm bundles were genotyped to determine whether different genotypes were present. Within the 14 mature colonies, we detected 10 colonies with more than one genotype (intracolonial genetic variability). Four out of these 10 mature colonies showed a transfer of different genotypes via the eggs to the next generation. In two out of these four cases, we found additional alleles, and in the two other cases, we found only a subset of alleles in the unfertilized eggs. Our results suggest that during reproduction of A. hyacinthus, more than one genotype per colony is able to reproduce. We discuss the occurrence of different genotypes within a single coral colony and the ability for those to release eggs which are genetically distinct.

Alteration of the Cortical Actin Cytoskeleton Deregulates Ca2+ Signaling, Monospermic Fertilization, and Sperm Entry

PubMed Central

Puppo, A.; Chun, Jong T.; Gragnaniello, Giovanni; Garante, Ezio; Santella, Luigia

2008-01-01

Background When preparing for fertilization, oocytes undergo meiotic maturation during which structural changes occur in the endoplasmic reticulum (ER) that lead to a more efficient calcium response. During meiotic maturation and subsequent fertilization, the actin cytoskeleton also undergoes dramatic restructuring. We have recently observed that rearrangements of the actin cytoskeleton induced by actin-depolymerizing agents, or by actin-binding proteins, strongly modulate intracellular calcium (Ca2+) signals during the maturation process. However, the significance of the dynamic changes in F-actin within the fertilized egg has been largely unclear. Methodology/Principal Findings We have measured changes in intracellular Ca2+ signals and F-actin structures during fertilization. We also report the unexpected observation that the conventional antagonist of the InsP3 receptor, heparin, hyperpolymerizes the cortical actin cytoskeleton in postmeiotic eggs. Using heparin and other pharmacological agents that either hypo- or hyperpolymerize the cortical actin, we demonstrate that nearly all aspects of the fertilization process are profoundly affected by the dynamic restructuring of the egg cortical actin cytoskeleton. Conclusions/Significance Our findings identify important roles for subplasmalemmal actin fibers in the process of sperm-egg interaction and in the subsequent events related to fertilization: the generation of Ca2+ signals, sperm penetration, cortical granule exocytosis, and the block to polyspermy. PMID:18974786

Influence of fertilizing water pH on the hatching success of stripped channel catfish eggs on channel x blue hybrid catfish embryo production in hatcheries

USDA-ARS?s Scientific Manuscript database

Variable egg quality is one of the most important constrains to the development of aquaculture. The quality of eggs that are manually stripped from channel catfish are affected by variation in parental genetics, maturity, type and dose of hormone, age and pre-spawning stress of female fish. Furthe...

Role of Caspase-3 Cleaved IP3R1 on Ca2+ Homeostasis and Developmental Competence of Mouse Oocytes and Eggs

PubMed Central

Zhang, Nan; Fissore, Rafael. A.

2014-01-01

Apoptosis in most cell types is accompanied by altered Ca2+ homeostasis. During apoptosis, caspase-3 mediated cleavage of the type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) generates a 95-kDa C-terminal fragment (C-IP3R1), which represents the channel domain of the receptor. Aged mouse eggs display abnormal Ca2+ homeostasis and express C-IP3R1, although whether or not C-IP3R1 expression contributes to Ca2+ misregulation or a decrease in developmental competency is unknown. We sought to answer these questions by injecting in mouse oocytes and eggs cRNAs encoding CIP3R1. We found that: 1) expression of C-IP3R1 in eggs lowered the Ca2+ content of the endoplasmic reticulum (ER), although, as C-IP3R1 is quickly degraded at this stage, its expression did not impair pre-implantation embryo development; 2) expression of CIP3R1 in eggs enhanced fragmentation associated with aging; 3) endogenous IP3R1 is required for aging associated apoptosis, as its down-regulation prevented fragmentation, and expression of C-IP3R1 in eggs with downregulated IP3R1 partly restored fragmentation; 4) C-IP3R1 expression in GV oocytes resulted in persistent levels of protein, which abolished the increase in the ER releasable Ca2+ pool that occurs during maturation, undermined the Ca2+ oscillatory ability of matured eggs and their activation potential. Collectively, this study supports a role for IP3R1 and C-IP3R1 in regulating Ca2+ homeostasis and the ER Ca2+ content during oocyte maturation. Nevertheless, the role of C-IP3R1 on Ca2+ homeostasis in aged eggs seems minor, as in MII eggs the majority of endogenous IP3R1 remains intact and C-IP3R1 undergoes rapid turnover. PMID:24692207

Mature Oocyte Cryopreservation for Fertility Preservation.

PubMed

Liang, Tina; Motan, Tarek

2016-01-01

In recent decades, advances in cancer treatment have led to a dramatic improvement in long term survival. This has led to an increasing focus on quality of life after surviving cancer treatment, with fertility being an important aspect. Given the known reproductive risks of cancer therapies, there has been a growing interest in the field of fertility preservation (also referred to as oncofertility). Mature oocyte cryopreservation is no longer considered experimental and has become a realistic option for reproductive aged women prior to undergoing cancer treatment. Additionally, as cryopreservation techniques improve, mature oocyte cryopreservation is increasing being marketed to healthy women without cancer wishing to delay child bearing, also termed "social egg freezing". This chapter provides a review of the current technology, use, and outcomes of mature oocyte cryopreservation. It also outlines the ethical debate surrounding social egg freezing and directions for future research in female fertility preservation.

Temperature-independent energy expenditure in early development of the African clawed frog Xenopus laevis.

PubMed

Nagano, Yatsuhisa; Ode, Koji L

2014-08-01

The thermal dissipation of activated eggs and embryos undergoing development from cleavage to the tailbud stage of the African clawed frog Xenopus laevis was measured as a function of incubation time at temperatures ranging from T = 288.2 K to 295.2 K, using a high-precision isothermal calorimeter. A23187-mediated activation of mature eggs induced stable periodic thermal oscillations lasting for 8-34 h. The frequency agreed well with the cell cycle frequency of initial cleavages at the identical temperature. In the developing embryo, energy metabolism switches from embryonic to adult features during gastrulation. The thermal dissipation after gastrulation fit well with a single modified Avrami equation, which has been used for modeling crystal-growth. Both the oscillation frequency of the activated egg and the growth rate of the embryo strongly depend on temperature with the same apparent activation energy of approximately 87 kJ mole(-1). This result suggests that early development proceeds as a single biological time, attributable to a single metabolic rate. A temperature-independent growth curve was derived by scaling the thermogram to the biological time, indicating that the amount of energy expenditure during each developmental stage is constant over the optimal temperature range.

Life history of Milnesium tardigradum Doyère (tardigrada) under a rearing environment.

PubMed

Suzuki, Atsushi C

2003-01-01

A strain of carnivorous tardigrade, Milnesium tardigradum, was reared in water on agar plates at 25 degrees C. The monogonont rotifer Lecane inermis was presented as a food source. This rearing system permitted detailed observation of tardigrade behaviour. Daily measurements of body length allowed the growth rate and moulting cycle of this species to be determined. The life history of M. tardigradum raised under these conditions included up to seven periods of moult. The first and second moults occurred at intervals of 4-5 days, and individuals reached reproductive maturity at the 3rd-instar stage; the first period of egg laying accompanied the third moult. The most rapidly developing animal in the study population laid eggs 12 days after hatching. The egg-laying intervals or moulting intervals of adult animals were around 6-10 days. The mean clutch size was 6.9 eggs. All tardigrades in this laboratory population were female and reproduced by parthenogenesis. The duration of the embryonic stage ranged from 5-16 days. The most long-lived female survived for 58 days after hatching, and laid a total of 41 eggs in 5 separate clutches. The entire life cycle of tardigrades reared under these conditions was recorded and photographed. A brief description of the embryonic development of M. tardigradum was also reported.

Deposition and maturation of eggs of Schistosoma mansoni in vitro: importance of fatty acids in serum-free media.

PubMed

Newport, G R; Weller, T H

1982-03-01

A serum-free medium which supports miracidial development in some eggs deposited by adult Schistosoma mansoni in vitro is described. Derivation of the medium involved examination of the supportiveness of nine chemically defined media, selection of one promoting the highest degree of worm oviposition, and supplementation of the latter with various serum fractions. The serum fraction supporting egg maturation was nondialyzable, and precipitated at 50-60% ammonium sulfate saturation. This fraction could be replaced by bovine serum albumin; however, the supportive activity disappeared if this material was delipidated. Addition of soybean lecithin, or stearic acid, to fatty-acid-free, albumin-supplemented media yielded intermediate results, while similar addition of other nonesterified fatty acids proved non stimulatory. A fatty acid mixture, rich in stearic acid, was then developed which, when added to delipidated-albumin supplemented media, supported a degree of egg development comparable to that obtained with media supplemented with 8% newborn calf serum.

Husbandry and care of quail

USGS Publications Warehouse

Ottinger, M.A.; Rattner, B.A.

1999-01-01

Both the Japanese and Bobwhite quail are important species for biomedical, toxicological and basic biological research. In view of their rapid maturation, high reproductive rate in captivity, and other physiological characteristics, these species have been and will continue to be used successfully as model avian species. This short reviews describes caging, environmental, and feed requirements for Japanese and Bobwhite quail maintained in captivity. Information on egg collection, incubation, care of young, handling, blood collection and common diseases are discussed.

Within-plant distribution of onion thrips (Thysanoptera: Thripidae) in onions.

PubMed

Mo, Jianhua; Munro, Scott; Boulton, Alan; Stevens, Mark

2008-08-01

Two aspects of the within-plant distribution of Thrips tabaci Lindeman (Thysanoptera: Thripidae) on onion, Allium cepa L., plants were investigated: 1) diurnal variations in the distribution of adults and larvae between basal and upper sections of onion leaves, and 2) between-leaf and within-leaf distribution of the eggs. The diurnal investigations showed that higher proportions of larvae than of adults congregated at the basal sections of plants, particularly when plants were young and thrips density was low. As plants matured and thrips density increased, the larvae became more dispersed. Regardless of plant size, there were always more adults in the upper than basal plant sections. There were no clear time-windows during the 24-h diurnal cycle when more thrips were in the upper plant parts. T. tabaci eggs were laid everywhere in the plant. Leaves of intermediate ages had more eggs than older or younger leaves. Within leaves, the white leaf sheath received the least eggs and leaf tips received slightly more eggs than leaf sheaths. The highest egg density was found between the green leaf base and the leaf tips. Regardless of plant size, more than half of all eggs were laid above the basal sections. The percentage increased to >95% in mature plants. Except when plants were small the outer leaves were preferred over inner leaves and upper leaf sections preferred over lower leaf sections as egg-laying sites by adults. Implications of the results in the management of T. tabaci are discussed.

Fertilizability of Superovulated Eggs by Estrous Stage-independent PMSG/hCG Treatment in Adult Wistar-Imamichi Rats

PubMed Central

Kon, Hiroe; Hokao, Ryoji; Shinoda, Motoo

2014-01-01

We investigated the fertilization and developmental ability of superovulated eggs obtained from adult Wistar-Imamichi (WI) rats, by using pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) treatment. Female WI rats, 11–13 weeks of age, were divided into four groups by estrous stage (metestrus [ME], diestrus [DE], proestrus [PE], or estrus [E]). PMSG (150 IU/kg) and hCG (75 IU/kg) were injected at an interval of 48 or 55 h and the female rats were mated with mature male rats. The ovulated eggs were collected 20, 24, and 27 h after hCG injection. Regardless of the estrous stage at the time of PMSG injection, the treated rats mated and ovulated similar to the untreated spontaneously ovulated rats (S group). Although the proportion of fertilized eggs in the E- and PE-treated groups was less than the S group 20 h after hCG injection, the proportion was not different among all treated and S groups 24 h after hCG injection. The proportion of fertilized eggs using in vitro fertilization and the proportion of offspring obtained from 2-cell stage embryo transfer did not differ among the treated and S groups. In comparison with PMSG/hCG-treated immature rats, mating and ovulation rate of adult rats were significantly higher. The proportion of fertilized eggs obtained from mated rats did not differ between immature and adult rats. These results demonstrate that adult WI rats are good egg donors for reproductive biotechnological studies using unfertilized or fertilized eggs. PMID:24770643

Maturation capacity, morphology and morphometric assessment of human immature oocytes after vitrification and in-vitro maturation

PubMed Central

Nazari, Saeedeh; Khalili, Mohammad Ali; Esmaielzadeh, Forouzan; Mohsenzadeh, Mehdi

2011-01-01

Background: In general, 15% of oocytes collected in ART cycles are immature. These oocytes may be cryopreserved further for use in in-vitro maturation (IVM) program. Objective: The aim of this study was to determine maturation capacity, morphometric parameters and morphology of human immature oocytes in both fresh IVM (fIVM) and vitrified-IVM (vIVM) oocytes. Materials and Methods: 93 women who underwent controlled ovarian stimulation for ART were included. The immature oocytes (n=203) were divided into two groups: the first group (n=101) directly matured in vitro; and the second group (n=102) first vitrified, then matured in vitro. All oocytes underwent IVM in Ham’s F10 supplemented with LH+FSH and human follicular fluid. After 48h of incubation, the oocyte maturation rates, as well as morphometric and morphologic characteristics were assessed using cornus imaging and were compared. Results: Oocyte maturation rates were reduced in vIVM, (40.4%), in comparison with fIVM (59.4%, p<0.001). Following morphometric assessment, there was no difference in the mean oocyte diameters (µm) between fIVM and vIVM, 156.3±6.8 and 154.07±9.9, respectively. Other parameters of perimeters, egg areas, as well as oocyte and ooplasm volumes were similar in two groups. In addition, more morphologic abnormalities, such as, vacuole, and dark oocyte were observed in vIVM oocytes. Conclusion: fIVM was more successful than vIVM groups. No statistical differences were noticed in morphometry assessment in two groups. This suggests that morphometric parameters can not be applied as prognosis factor in oocyte maturation outcome in IVM program. PMID:26396566

An Electron Microscope Study of the Rat Ovum

PubMed Central

Sotelo, J. Roberto; Porter, Keith R.

1959-01-01

This paper reports on the fine structure of rat oocytes at stages before ovulation, during maturation, fertilization, and early cleavage. The study includes parallel observations on light and electron microscope preparations with attempted correlations. The follicular cells of the ovarian egg are described as sending long processes through the zona pellucida to the egg surface where they mingle with thin projections from the egg itself. No open communication between follicle cell cytoplasm and egg cytoplasm was observed. During maturation and fertilization both types of processes are withdrawn from the zona. The germinal vesicle and later the pronuclei of the fertilized egg are characterized by numerous large nucleoli. These have the form of thick walled vesicles with diameters as great as 8 to 10 µ. The wall is dense in the EM image and appears to consist in part of small granules. The cytoplasm shows several inclusions including mitochondria of usual form and a Golgi component which has the typical fine structure and the distribution described by earlier light studies. Small dense particles, presumably RNP particles, are distributed throughout the cytoplasmic matrix and show no preference for membranes. The endoplasmic reticulum of the oocyte is represented by a scattering only of vesicles, but begins a more extensive and elaborate development with the onset of segmentation. One inclusion of the ooplasm, similar in size to mitochondria, receives special attention. It is a vesicular structure, containing a large number of small vesicles (10 to 50 mµ in diameter) and frequently a central density or nucleoid. They are referred to as multivesicular bodies. Such bodies are found in small number in the ovarian egg, but increase greatly in number during maturation and fertilization. It appears from the micrographs of eggs in these latter stages that these vesicular bodies break down and liberate their content of small vesicles to the surrounding ooplasm. Comments are provided on the apparent significance of the various observations. PMID:13654454

Effects of Schistosoma haematobium infection on reproductive success and male outcrossing ability in the simultaneous hermaphrodite, Bulinus truncatus (Gastropoda: Planorbidae).

PubMed

Schrag, S J; Rollinson, D

1994-01-01

The schistosome intermediate snail host, Bulinus truncatus (Mollusca: Planorbidae), has two reproductive (phally) morphs. Both aphallics and euphallics can self-fertilize, but aphallics cannot donate sperm because they do not develop a functional penis and prostate. This study investigated the interactions between phally and fitness consequences of Schistosoma haematobium infection in B. truncatus. Snails which developed patent infections produced 26% fewer eggs than controls and 35% fewer eggs than exposed snails which did not develop infections. This reduction was due to a lower lifetime production of egg masses and a smaller mean number of eggs/mass in infected snails relative to control or exposed snails. However, there was no evidence of increased mortality in infected snails. Contrary to reports of fecundity compensation in other intermediate host snails, egg production post-exposure during the pre-patent period did not increase relative to that of controls in either infected or exposed snails. Phally did not influence susceptibility to infection or length of the prepatent period. Furthermore, lifetime egg, egg mass and hatchling production, as well as mean eggs/mass and number of hatchlings reaching maturity, did not differ significantly between aphallics and euphallics within control of exposed experimental groups. However, within the infected group euphallics produced 38% fewer eggs, smaller egg masses, and fewer hatchlings reaching maturity than aphallics, supporting the prediction of a cost to the growth and maintenance of a full male tract. This cost was detectable only when snails were under the stress of infection. The proportion of euphallic offspring produced did not differ across experimental groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental evidence of a dual endocrine control of biosynthesis in the main nidamental glands of Sepia officinalis L. by factors from the central nervous system and the ovary.

PubMed

Henry, J; Boucaud-Camou, E

1993-12-01

1. A rapid, reliable and quantitative in vitro bioassay was developed to study the endocrine control of the biosynthesis of the egg capsule: incorporation of 14C-labelled D-glucose in polysaccharides and glycoproteins increased in dispersed-cell suspensions of main nidamental glands from maturing females. 2. Brain, optic lobes (OL) and ovary extracts from mature and maturing females stimulated the incorporation of 14C-labelled D-glucose in polysaccharidic and glycoproteic fractions of a nidamental cell suspension, whereas optic gland (OG) had no effect. 3. These results bring the first experimental evidence that one of the spawning events (egg-capsule edification) is controlled by the central nervous system and the ovary in a cephalopod.

Effects of sexual maturation and Salmonella infection on the expression of Toll-like receptors in the chicken vagina.

PubMed

Michailidis, G; Theodoridis, A; Avdi, M

2011-02-01

Toll-like receptors (TLRs) are a critical component of the innate immune response in many vertebrates, including avian species. The recent findings of chicken TLRs (cTLRs) expression in ovarian follicles and in the chicken ovary in vivo, as well as the changes in their expression in response to lipopolysaccharide or Salmonella enteritidis (SE) infection, have broad implications for reproductive physiology and for the prevention of transmission of zoonotic diseases to humans through the consumption of contaminated poultry eggs. Because the main route of egg contamination is from infection of the oviduct and mainly from the vagina, the aim of this study was to investigate the expression of the ten cTLRs identified to date in the chicken oviduct in vivo, to determine whether sexual maturation affects their mRNA abundance and to investigate whether SE infection alters the expression of TLRs in the chicken vagina. RNA was extracted from the vagina of healthy prepubertal, sexually mature and aged birds, and from sexually mature and aged SE infected birds. RT-PCR analysis revealed that all types of cTLRs apart from TLR1-1 were expressed in the vagina of sexually mature birds. Quantitative real-time PCR analysis revealed that the mRNA abundance of TLR2-1, 2-2 and 4 differ with respect to sexual maturation in the chicken vagina. SE infection resulted in a significant induction of TLR5 and 15 in the vagina of sexually mature birds, and in a significant induction of TLR2-1, 4 and 15 in the vagina of aged birds, while a significant down-regulation was observed for TLR7 in the vagina of sexually mature birds. These findings suggest that a TLR mediated immune response mechanism exists in the chicken vagina, playing a crucial role in preventing microbial pathogens from being incorporated into newly forming eggs. Copyright © 2011 Elsevier B.V. All rights reserved.

Reproductive physiology

USGS Publications Warehouse

Gee, G.F.; Russman, S.E.; Ellis, David H.; Gee, George F.; Mirande, Claire M.

1996-01-01

Conclusions: Although the general pattern of avian physiology applies to cranes, we have identified many physiological mechanisms (e.g., effects of disturbance) that need further study. Studies with cranes are expensive compared to those done with domestic fowl because of the crane's larger size, low reproductive rate, and delayed sexual maturity. To summarize, the crane reproductive system is composed of physiological and anatomical elements whose function is controlled by an integrated neural-endocrine system. Males generally produce semen at a younger age than when females lay eggs. Eggs are laid in clutches of two (1 to 3), and females will lay additional clutches if the preceding clutches are removed. Both sexes build nests and incubate the eggs. Molt begins during incubation and body molt may be completed annually in breeding pairs. However, remiges are replaced sequentially over 2 to 3 years, or abruptly every 2 to 3 years in other species. Most immature birds replace their juvenal remiges over a 2 to 3 year period. Stress interferes with reproduction in cranes by reducing egg production or terminating the reproductive effort. In other birds, stress elevates corticosterone levels and decreases LHRH release. We know little about the physiological response of cranes to stress.

An autosomal dwarfism in the domestic fowl.

PubMed

Cole, R K

2000-11-01

A mutation in the Cornell K-strain of White Leghorns, first recognized when two adult males in a pedigreed family were definitely smaller than their two other brothers, proved to be an autosomal recessive mutation and gave rise to the autosomal dwarf stock. The effect of this gene (adw) can be recognized during embryonic development and leads to a normal adult, except for a 30% reduction in body weight. Selection for small size, egg production, and egg weight over a period of 15 yr yielded an efficient layer. Production for 11 mo from first egg was at a rate of 70%, with egg weight at 56 g and body weight at 1,160 g at 10 to 11 mo of age, based on data for the last four generations. Viability of the caged hens averaged over 95% for the 13 generations involved. Sexual maturity was delayed by about 2 wk, and good incubation (85+%) required 18+/- more hours than normal. When an autosomal dwarf male is used as a sire and mated to sex-linked dwarf (dw) females, all progeny are of normal size. Compared with problems of mating normal size males with dwarf females, the use of the two types of dwarfism can yield good fertility.

Prophase I Mouse Oocytes Are Deficient in the Ability to Respond to Fertilization by Decreasing Membrane Receptivity to Sperm and Establishing a Membrane Block to Polyspermy1

PubMed Central

Kryzak, Cassie A.; Moraine, Maia M.; Kyle, Diane D.; Lee, Hyo J.; Cubeñas-Potts, Caelin; Robinson, Douglas N.; Evans, Janice P.

2013-01-01

ABSTRACT Changes occurring as the prophase I oocyte matures to metaphase II are critical for the acquisition of competence for normal egg activation and early embryogenesis. A prophase I oocyte cannot respond to a fertilizing sperm as a metaphase II egg does, including the ability to prevent polyspermic fertilization. Studies here demonstrate that the competence for the membrane block to polyspermy is deficient in prophase I mouse oocytes. In vitro fertilization experiments using identical insemination conditions result in monospermy in 87% of zona pellucida (ZP)-free metaphase II eggs, while 92% of ZP-free prophase I oocytes have four or more fused sperm. The membrane block is associated with a postfertilization reduction in the capacity to support sperm binding, but this reduction in sperm-binding capacity is both less robust and slower to develop in fertilized prophase I oocytes. Fertilization of oocytes is dependent on the tetraspanin CD9, but little to no release of CD9 from the oocyte membrane is detected, suggesting that release of CD9-containing vesicles is not essential for fertilization. The deficiency in membrane block establishment in prophase I oocytes correlates with abnormalities in two postfertilization cytoskeletal changes: sperm-induced cortical remodeling that results in fertilization cone formation and a postfertilization increase in effective cortical tension. These data indicate that cortical maturation is a component of cytoplasmic maturation during the oocyte-to-egg transition and that the egg cortex has to be appropriately primed and tuned to be responsive to a fertilizing sperm. PMID:23863404

Generation of eggs from mouse embryonic stem cells and induced pluripotent stem cells.

PubMed

Hayashi, Katsuhiko; Saitou, Mitinori

2013-08-01

Oogenesis is an integrated process through which an egg acquires the potential for totipotency, a fundamental condition for creating new individuals. Reconstitution of oogenesis in a culture that generates eggs with proper function from pluripotent stem cells (PSCs) is therefore one of the key goals in basic biology as well as in reproductive medicine. Here we describe a stepwise protocol for the generation of eggs from mouse PSCs, such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). ESCs and iPSCs are first induced into primordial germ cell-like cells (PGCLCs) that are in turn aggregated with somatic cells of female embryonic gonads, the precursors for adult ovaries. Induction of PGCLCs followed by aggregation with the somatic cells takes up to 8 d. The aggregations are then transplanted under the ovarian bursa, in which PGCLCs grow into germinal vesicle (GV) oocytes in ∼1 month. The PGCLC-derived GV oocytes can be matured into eggs in 1 d by in vitro maturation (IVM), and they can be fertilized with spermatozoa by in vitro fertilization (IVF) to obtain healthy and fertile offspring. This method provides an initial step toward reconstitution of the entire process of oogenesis in vitro.

Bemisia tabaci females from the Mediterranean (Q) species detect and avoid laying eggs in the presence of pyriproxyfen, a juvenile hormone analogue.

PubMed

Moshitzky, Pnina; Morin, Shai

2014-10-01

Pyriproxyfen, a juvenile hormone analogue, disrupts embryogenesis, metamorphosis and adult formation in Bemisia tabaci, but does not directly affect adult females. The effect of pyriproxyfen on egg-laying preference and performance of B. tabaci females and the influence of resistance to pyriproxyfen on these reproductive behaviours were studied. Choice experiments utilising cotton plants treated and not treated with pyriproxyfen revealed a significant preference for egg laying on non-treated plants both by resistant and susceptible females. No-choice assays indicated a reduction of ∼60% in the number of eggs laid on pyriproxyfen-treated plants by both resistant and susceptible females. The reduction in oviposition on treated plants was not accompanied with reduced expression of the vitellogenin gene or a delay in oocyte maturation, but significant accumulation of mature oocytes in the ovaries was observed, and could be reversed by transferring the females to non-treated plants. Pyriproxyfen caused reduced oviposition and enhanced mature oocyte accumulation in pyriproxyfen-resistant and pyriproxyfen-susceptible females. These findings can be explained by two alternative mechanisms: pyriproxyfen-regulated physiological arrest of oviposition, involving hormonal regulation of myotrophic factors, or the hierarchy-threshold behavioural theory of host choice, in which pyriproxyfen-treated plants are defined as low-quality hosts. Aspects of application are discussed. © 2013 Society of Chemical Industry.

MicroRNAs Are Involved in the Regulation of Ovary Development in the Pathogenic Blood Fluke Schistosoma japonicum.

PubMed

Zhu, Lihui; Zhao, Jiangping; Wang, Jianbin; Hu, Chao; Peng, Jinbiao; Luo, Rong; Zhou, Chunjing; Liu, Juntao; Lin, Jiaojiao; Jin, Youxin; Davis, Richard E; Cheng, Guofeng

2016-02-01

Schistosomes, blood flukes, are an important global public health concern. Paired adult female schistosomes produce large numbers of eggs that are primarily responsible for the disease pathology and critical for dissemination. Consequently, understanding schistosome sexual maturation and egg production may open novel perspectives for intervening with these processes to prevent clinical symptoms and to interrupt the life-cycle of these blood-flukes. microRNAs (miRNAs) are key regulators of many biological processes including development, cell proliferation, metabolism, and signal transduction. Here, we report on the identification of Schistosoma japonicum miRNAs using small RNA deep sequencing in the key stages of male-female pairing, gametogenesis, and egg production. We identified 38 miRNAs, including 10 previously unknown miRNAs. Eighteen of the miRNAs were differentially expressed between male and female schistosomes and during different stages of sexual maturation. We identified 30 potential target genes for 16 of the S. japonicum miRNAs using antibody-based pull-down assays and bioinformatic analyses. We further validated some of these target genes using either in vitro luciferase assays or in vivo miRNA suppression experiments. Notably, suppression of the female enriched miRNAs bantam and miR-31 led to morphological alteration of ovaries in female schistosomes. These findings uncover key roles for specific miRNAs in schistosome sexual maturation and egg production.

Oviposition Preference and Survival of the Mexican Rice Borer (Lepidoptera: Crambidae) in Bioenergy and Conventional Sugarcane and Sorghum.

PubMed

VanWeelden, M T; Wilson, B E; Beuzelin, J M; Reagan, T E; Way, M O

2017-08-01

Oviposition preference and host suitability of the Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), on bioenergy and conventional cultivars of sugarcane, Saccharum spp., and sorghum, Sorghum spp., were examined in a series of greenhouse experiments. Two energycane cultivars, two sugarcane cultivars, two high-biomass sorghum cultivars, and one sweet sorghum cultivar were assessed at two phenological stages (immature and mature). Mature plants possessed greater availability of dry leaf material compared with immature plants, and all E. loftini eggs were observed exclusively on dry leaves. Oviposition did not vary among host combinations (cultivar by phenological stage); however, eggs per plant and eggs per oviposition event were numerically greater on mature plants than immature plants. In a no-choice experiment, survival from egg to adult did not vary among host combinations, with <2.0% of E. loftini larvae surviving to adulthood. Failed establishment by neonates on plants was 13.4- to 53.9-fold greater than successful establishment across all host combinations. Results from this study suggest that plant physical characteristics continue to play an important role in host selection, but further evaluations will be needed to quantify other characteristics which influence host suitability. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

MicroRNAs Are Involved in the Regulation of Ovary Development in the Pathogenic Blood Fluke Schistosoma japonicum

PubMed Central

Hu, Chao; Peng, Jinbiao; Luo, Rong; Zhou, Chunjing; Liu, Juntao; Lin, Jiaojiao; Jin, Youxin; Davis, Richard E.; Cheng, Guofeng

2016-01-01

Schistosomes, blood flukes, are an important global public health concern. Paired adult female schistosomes produce large numbers of eggs that are primarily responsible for the disease pathology and critical for dissemination. Consequently, understanding schistosome sexual maturation and egg production may open novel perspectives for intervening with these processes to prevent clinical symptoms and to interrupt the life-cycle of these blood-flukes. microRNAs (miRNAs) are key regulators of many biological processes including development, cell proliferation, metabolism, and signal transduction. Here, we report on the identification of Schistosoma japonicum miRNAs using small RNA deep sequencing in the key stages of male-female pairing, gametogenesis, and egg production. We identified 38 miRNAs, including 10 previously unknown miRNAs. Eighteen of the miRNAs were differentially expressed between male and female schistosomes and during different stages of sexual maturation. We identified 30 potential target genes for 16 of the S. japonicum miRNAs using antibody-based pull-down assays and bioinformatic analyses. We further validated some of these target genes using either in vitro luciferase assays or in vivo miRNA suppression experiments. Notably, suppression of the female enriched miRNAs bantam and miR-31 led to morphological alteration of ovaries in female schistosomes. These findings uncover key roles for specific miRNAs in schistosome sexual maturation and egg production. PMID:26871705

First observations of fertilized eggs and preleptocephalus larvae of Rhinomuraena quaesita in the Vienna Zoo.

PubMed

Preininger, D; Halbauer, R; Bartsch, V; Weissenbacher, A

2015-01-01

For the first time worldwide, fertilized eggs of ribbon eels (Rhinomuraena quaesita) hatched into feeding preleptocephali and could be kept alive for a period of seven days in the Vienna Zoo. The study reports on husbandry, behavioral observations and dimensions of eggs and preleptocephalus larvae. Furthermore, body color variations of ribbon eels in captivity do not reflect its sex or sexual maturity. © 2014 Wiley Periodicals, Inc.

Histological study on maturation, fertilization and the state of gonadal region following spawning in the model sea anemone, Nematostella vectensis

PubMed Central

Moiseeva, Elizabeth; Rabinowitz, Claudette; Rinkevich, Baruch

2017-01-01

The starlet sea-anemone Nematostella vectensis has emerged as a model organism in developmental biology. Still, our understanding of various biological features, including reproductive biology of this model species are in its infancy. Consequently, through histological sections, we study here key stages of the oogenesis (oocyte maturation/fertilization), as the state of the gonad region immediately after natural spawning. Germ cells develop in a secluded mesenterial gastrodermal zone, where the developing oocytes are surrounded by mucoid glandular cells and trophocytes (accessory cells). During vitellogenesis, the germinal vesicle in oocytes migrates towards the animal pole and the large polarized oocytes begin to mature, characterized by karyosphere formation. Then, the karyosphere breaks down, the chromosomes form the metaphase plate I and the eggs are extruded from the animal enclosed in a sticky, jelly-like mucoid mass, along with numerous nematosomes. Fertilization occurs externally at metaphase II via swimming sperm extruded by males during natural spawning. The polar bodies are ejected from the eggs and are situated within a narrow space between the egg’s vitelline membrane and the adjacent edge of the jelly coat. The cortical reaction occurs only at the polar bodies’ ejection site. Several spermatozoa can penetrate the same egg. Fertilization is accompanied by a strong ooplasmatic segregation. Immediately after spawning, the gonad region holds many previtellogenic and vitellogenic oocytes, though no oocytes with karyosphere. Above are the first histological descriptions for egg maturation, meiotic chromosome’s status at fertilization, fertilization and the gonadal region’s state following spawning, also documenting for the first time the ejection of the polar body. PMID:28796817

Impacts of metformin and aspirin on life history features and longevity of crickets: trade-offs versus cost-free life extension?

PubMed

Hans, Harvir; Lone, Asad; Aksenov, Vadim; Rollo, C David

2015-01-01

We examined the impacts of aspirin and metformin on the life history of the cricket Acheta domesticus (growth rate, maturation time, mature body size, survivorship, and maximal longevity). Both drugs significantly increased survivorship and maximal life span. Maximal longevity was 136 days for controls, 188 days (138 % of controls) for metformin, and 194 days (143 % of controls) for aspirin. Metformin and aspirin in combination extended longevity to a lesser degree (163 days, 120 % of controls). Increases in general survivorship were even more pronounced, with low-dose aspirin yielding mean longevity 234 % of controls (i.e., health span). Metformin strongly reduced growth rates of both genders (<60 % of controls), whereas aspirin only slightly reduced the growth rate of females and slightly increased that of males. Both drugs delayed maturation age relative to controls, but metformin had a much greater impact (>140 % of controls) than aspirin (~118 % of controls). Crickets maturing on low aspirin showed no evidence of a trade-off between maturation mass and life extension. Remarkably, by 100 days of age, aspirin-treated females were significantly larger than controls (largely reflecting egg complement). Unlike the reigning dietary restriction paradigm, low aspirin conformed to a paradigm of "eat more, live longer." In contrast, metformin-treated females were only ~67 % of the mass of controls. Our results suggest that hormetic agents like metformin may derive significant trade-offs with life extension, whereas health and longevity benefits may be obtained with less cost by agents like aspirin that regulate geroprotective pathways.

Characteristics and incidence of large eggs in Trichuris muris.

PubMed

Koyama, Koichi

2013-05-01

The production of small numbers of large eggs among the standard-sized eggs of Trichuris trichiura is well known. Large eggs have also been observed in Trichuris muris, but they have not been studied previously. This paper compares the characteristics of the large eggs (LEs, ≥74.5 μm long) and standard-sized eggs (SEs, <74.5 μm long) in cultures of T. muris. Among 112,554 cultured eggs, LEs occurred at very low frequency (0.03 %, i.e., about three large eggs per 10(4) cultured eggs). Embryonated eggs represented 93.72 % of SEs, but only 25.00 % of LEs were embryonated. Embryonated LEs and SEs contained fully matured larvae. An atypical category of unembryonated egg, which contained an incompletely developed larva, an abnormal larva, or granular components, was common among the LEs. However, similar atypical unembryonated SEs were rarely observed. These observations suggest that the LEs that occur very infrequently in T. muris result from an abnormality of embryonation (larval development).

Acute exposure to gas-supersaturated water does not affect reproductive success of female adult chinook salmon late in maturation

USGS Publications Warehouse

Gale, William L.; Maule, A.G.; Postera, A.; Peters, M.H.

2004-01-01

At times, total dissolved gas concentrations in the Columbia and Snake rivers have been elevated due to involuntary spill from high spring runoff and voluntary spill used as a method to pass juvenile salmonids over dams. The goal of this project was to determine if acute exposure to total dissolved gas supersaturation (TDGS) affects the reproductive performance of female chinook salmon late in their maturation. During this study, adult female spring chinook salmon were exposed to mean TDGS levels of 114.1 % to 125.5%. We ended exposures at first mortality, or at the appearance of impending death. Based on this criterion, exposures lasted from 10 to 68 h and were inversely related to TDGS. There was no effect of TDGS on pre-spawning mortality or fecundity when comparing treatment fish to experimental controls or the general hatchery population four to six weeks after exposures. Egg quality, based on egg weight and egg diameter, did not differ between treatment and control fish. Fertilization rate and survival to eyed-stage was high (>94%) for all groups. With the exception of Renibacterium salmoninarum (the causative agent of bacterial kidney disease; BKD), no viral or bacterial fish pathogens were isolated from experimental fish. The prevalence (about 45%) and severity of R. salmoninarum did not differ among the groups or the general hatchery population. We conclude that these acute exposures to moderate levels of gas-supersaturated water-perhaps similar to that experienced by immigrating adult salmon as they approach and pass a hydropower dam on the Columbia River-did not affect reproductive success of female chinook salmon late in their maturation. These results are most applicable to summer and fall chinook salmon, which migrate in the summer/fall and spawn shortly after reaching their natal streams. Published in 2004 by John Wiley and Sons, Ltd.

Assigning sex and reproductive stage to adult Lake Sturgeon using ultrasonography and common morphological measurements

USGS Publications Warehouse

Chiotti, Justin A.; Boase, James C.; Hondorp, Darryl W.; Briggs, Andrew S.

2016-01-01

Sex determination of fish species is difficult to assess when sexual dimorphism and gametes are not apparent. For threatened and endangered fish species, noninvasive techniques are needed when determining sex to minimize stress and the potential for mortality. We evaluated the use of a portable ultrasound unit to determine sex of Lake Sturgeon Acipenser fulvescens in the field. Ultrasound images were collected from 9 yellow-egg (F2, F3), 32 black-egg (F4, F5), and 107 fully developed male (M2) Lake Sturgeon. Two readers accurately assigned sex to 88–96% of fish, but accuracy varied in relation to maturity stage. Black-egg females and fully developed males were correctly identified for 89–100% of the fish sampled, while these two readers identified yellow-egg females only 33% and 67% of the time. Time spent collecting images ranged between 2 and 3 min once the user was comfortable with operating procedures. Discriminant analysis revealed the total length : girth ratio was a strong predictor of sex and maturity, correctly classifying 81% of black-egg females and 97% of the fully developed males. However, yellow-egg females were incorrectly classified on all occasions. This study shows the utility of using ultrasonography and a total length : girth ratio for sex determination of Lake Sturgeon in later reproductive stages around the spawning season.

Steroidogenic follicular response differences to LH and FSH treatment in low and high egg producing turkey hens

USDA-ARS?s Scientific Manuscript database

Low egg production in turkey hens is correlated with decreased ovulation frequency. Ovulation frequency is governed at the ovarian level by the steroid hormones progesterone and estradiol. The avian ovary is comprised of follicles in varying stages of maturation, which serve specialized roles in ste...

Organochlorine pesticides and thiamine in eggs of largemouth bass and American alligators and their relationship with early life-stage mortality

USGS Publications Warehouse

Sepulveda, M.S.; Wiebe, J.J.; Honeyfield, D.C.; Rauschenberger, H.R.; Hinterkopf, J.P.; Johnson, W.E.; Gross, T.S.

2004-01-01

Thiamine deficiency has been linked to early mortality syndrome in salmonids in the Great Lakes. This study was conducted to compare thiamine concentrations in American alligators (Alligator mississippiensis) and Florida largemouth bass (Micropterus salmoides floridanus) eggs from sites with high embryo mortality and high exposure to organochlorine pesticides (OCPs) (Lakes Apopka and Griffin, and Emeralda Marsh, Florida, USA) to those from sites that have historically exhibited low embryo mortality and low OCPs (Lakes Woodruff and Orange, Florida). During June-July 2000, 20 alligator clutches were collected from these sites, artificially incubated, and monitored for embryo mortality. Thiamine and OCPs were measured in one egg/clutch. During February 2002, 10 adult female bass were collected from Emeralda Marsh and Lake Woodruff and mature ovaries analyzed for thiamine and OCP concentrations. Although ovaries from the Emeralda Marsh bass contained almost 1,000-fold more OCPs compared with the reference site, Lake Woodruff, there were no differences in thiamine concentrations between sites (11,710 vs. 11,857 pmol/g). In contrast, alligator eggs from the reference site had five times the amount of thiamine compared with the contaminated sites (3,123 vs. 617 pmol/g). Similarly, clutches with > 55% hatch rates had significantly higher concentrations of thiamine compared with clutches with <54% hatch rates (1,119 vs. 201 pmol/g). These results suggest that thiamine deficiency might be playing an important role in alligator embryo survival but not in reproductive failure and recruitment of largemouth bass. The cause(s) of this thiamine deficiency are unknown but might be related to differences in the nutritional value of prey items across the sites studied and/or to the presence of high concentration of contaminants in eggs. ?? Wildlife Disease Association 2004.

Comparing sugar type supplementation for cryopreservation of boar semen in egg yolk based extender.

PubMed

Malo, C; Gil, L; Gonzalez, N; Cano, R; de Blas, I; Espinosa, E

2010-08-01

Cryopreservation of boar semen is still considered suboptimal due to lower fertility when compared to fresh semen. The aim of this study was to evaluate the effects of the addition of different sugars (lactose, trehalose and glucose) on boar spermatozoa cryopreserved in an egg yolk based extender. Ejaculates were collected from a boar previously selected and semen samples were processed using the straw freezing procedure. In experiment 1, subsamples of semen were frozen in three different extenders: recommended lactose egg yolk extender (LEY); trehalose egg yolk extender (TEY) and glucose egg yolk extender (GEY). Sperm quality was assessed for motility, viability, acrosome integrity and hypoosmotic swelling test response upon collection, after freezing and thawing and then every hour for 3h. Results showed that total motility at 1 and 3h, progressive motility at 3h, positive hypoosmotic response at 2 and 3h and acrosome integrity at all times were significantly improved when trehalose was added to the extender. In experiment 2, sugar influence was also demonstrated in vitro fertilization. A total of 1691 oocytes were in vitro matured and inseminated with frozen-thawed sperm at 2000:1 sperm:oocyte ratio and coincubated for 6h. Presumptive zygotes were cultured in NCSU-23 medium to assess fertilization parameters and embryo development. Both penetration and monospermy rates were significantly higher for trehalose frozen semen. A significant increase was observed in efficiency and blastocyst formation rates from TEY to the other groups. Our results demonstrated that trehalose extender enhances spermatozoa viability and its in vitro fertilization parameters in boar ejaculates with good sperm freezability. Further studies are necessary to assess the impact of sugars on the entire population. (c) 2010 Elsevier Inc. All rights reserved.

Organochlorine pesticides and thiamine in eggs of largemouth bass and American alligators and their relationship with early life-stage mortality.

PubMed

Sepúlveda, Maria S; Wiebe, Jon J; Honeyfield, Dale C; Rauschenberger, Heath R; Hinterkopf, Joy P; Johnson, William E; Gross, Timothy S

2004-10-01

Thiamine deficiency has been linked to early mortality syndrome in salmonids in the Great Lakes. This study was conducted to compare thiamine concentrations in American alligators (Alligator mississippiensis) and Florida largemouth bass (Micropterus salmoides floridanus) eggs from sites with high embryo mortality and high exposure to organochlorine pesticides (OCPs) (Lakes Apopka and Griffin, and Emeralda Marsh, Florida, USA) to those from sites that have historically exhibited low embryo mortality and low OCPs (Lakes Woodruff and Orange, Florida). During June-July 2000, 20 alligator clutches were collected from these sites, artificially incubated, and monitored for embryo mortality. Thiamine and OCPs were measured in one egg/clutch. During February 2002, 10 adult female bass were collected from Emeralda Marsh and Lake Woodruff and mature ovaries analyzed for thiamine and OCP concentrations. Although ovaries from the Emeralda Marsh bass contained almost 1,000-fold more OCPs compared with the reference site, Lake Woodruff, there were no differences in thiamine concentrations between sites (11,710 vs. 11,857 pmol/g). In contrast, alligator eggs from the reference site had five times the amount of thiamine compared with the contaminated sites (3,123 vs. 617 pmol/g). Similarly, clutches with >55% hatch rates had significantly higher concentrations of thiamine compared with clutches with <54% hatch rates (1,119 vs. 201 pmol/g). These results suggest that thiamine deficiency might be playing an important role in alligator embryo survival but not in reproductive failure and recruitment of largemouth bass. The cause(s) of this thiamine deficiency are unknown but might be related to differences in the nutritional value of prey items across the sites studied and/or to the presence of high concentration of contaminants in eggs.

[PKA-regulated phosphorylation status of S149 and S321 sites of CDC25B inhibits mitosis of fertilized mouse eggs].

PubMed

Xiao, Jian-Ying; Liu, Chao; Sun, Xiao-Han; Yu, Bing-Zhi

2012-02-25

To further test whether protein kinase A (PKA) can affect the mitotic cell cycle, one-cell stage mouse embryos at S phase (22 h after hCG injection) were incubated in M16 medium containing various concentrations of H-89, a PKA inhibitor. With increasing concentrations of H-89 (0-50 μmol/L), the G(2) phase of eggs was decreased and the cleavage rate was accelerated. A concentration of 40 μmol/L H-89 led to all of the mouse eggs entering the M phase of mitosis. Furthermore, to study the role of PKA in regulating the phosphorylation status of S149 and S321 sites of cell division cycle 25B (CDC25B) on one-cell stage fertilized mouse eggs, pBSK-CDC25B-WT, pBSK-CDC25B-S149A, pBSK-CDC25B-S321A and pBSK-CDC25B-S149A/S321A were transcribed into mRNAs in vitro, then mRNAs were microinjected into S phase of mouse fertilized eggs and cultured in M16 medium pretreated with H-89. Then, the cleavage of fertilized eggs, maturation promoting factor (MPF) activity and phosphorylation status of CDC2-Tyr15 were observed. In the presence of 40 μmol/L H-89, the cleavage rate of fertilized eggs in CDC25B-S/A-mRNAs and CDC25B-WT-mRNA injected groups was significantly higher than that in the control groups, and the peak of MPF activity appeared in the CDC25B-S/A-mRNAs and CDC25B-WT-mRNA injected groups earlier than that in the control groups. CDC2-Tyr15 phosphorylation state was consistent with MPF activity. In conclusion, the present study suggests that PKA regulates the early development of mouse embryos by phosphorylation of S149 and S321 of CDC25B, which plays an important role in the regulation of G(2)/M transition in the mitotic cell cycle of fertilized mouse eggs.

Oocyte size, egg index, and body lipid content in relation to body size in the solitary bee Megachile rotundata.

PubMed

O'Neill, Kevin M; Delphia, Casey M; O'Neill, Ruth P

2014-01-01

Females of solitary, nest-provisioning bees have relatively low fecundity, but produce large eggs as part of their overall strategy of investing substantially in each offspring. In intraspecific comparisons of several species of solitary, nest-provisioning bees and wasps, the size of the mature eggs produced increases with female body size. We further examined oocyte size-body size correlations in the solitary bee Megachile rotundata (F.), an important crop pollinator. We hypothesized that larger females carry larger basal oocytes (i.e., those next in line to be oviposited) but that body size-oocyte size correlations would be absent soon after emergence, before their first eggs fully matured. Because egg production is likely affected by the quantity of stored lipids carried over from the bees' immature stages, we also tested the hypothesis that female body size is correlated with the body lipid content at adult emergence, the time during which oocyte growth accelerates. We found significant correlations of body size with oocyte size variables chosen to reflect: (1) the magnitude of the investment in the next egg to be laid (i.e., the length and volume of the basal oocyte) and (2) the longer term potential to produce mature oocytes (i.e., the summed lengths and volumes of the three largest oocytes in each female). Positive correlations existed throughout the nesting season, even during the first week following adult emergence. The ability to produce and carry larger oocytes may be linked to larger females starting the nesting season with greater lipid stores (which we document here) or to greater space within the abdomen of larger females. Compared to other species of solitary bees, M. rotundata appears to have (1) smaller oocytes than solitary nest-provisioning bees in general, (2) comparable oocyte sizes relative to congeners, and (3) larger oocytes than related brood parasitic megachilids.

Factors affecting broiler breeder performance. 5. Effects of preproduction feeding regimens on reproductive performance.

PubMed

McDaniel, G R

1983-10-01

Three preproduction feeding regimens were used to determine their effects on reproductive performance of broiler breeder females. Three hundred 16-week-old Arbor Acre females were divided into three treatment groups. Treatment 1 was placed on full feed at 17 weeks of age and remained on this schedule for 5 weeks. At 22 weeks of age they were placed on a diet consisting of 136 g of feed per bird per day and remained on this schedule until the experiment was terminated at 60 weeks of age. Treatments 2 and 3 reached peak feed intake at 26 and 30 weeks of age, respectively. Age at maturity, eggs per hen housed, and feed conversion were significantly affected by preproduction feeding regimens. Treatment 1 matured significantly earlier than Treatments 2 and 3; however, feed conversion was significantly higher (grams of feed per egg) than in Treatments 2 and 3. In general, shell quality; and egg weights were lower in Treatment 1 than in Treatments 2 and 3 throughout most of the experiment. There were no differences in shell quality or egg weights between Treatments 2 or 3. There was a significant difference in egg production among all treatments at the 60-week production period, Treatment 1 being the lowest and Treatment 3 being the highest.

Temperature-dependent sex determination modulates cardiovascular maturation in embryonic snapping turtles Chelydra serpentina.

PubMed

Alvine, Travis; Rhen, Turk; Crossley, Dane A

2013-03-01

We investigated sex differences in cardiovascular maturation in embryos of the snapping turtle Chelydra serpentina, a species with temperature-dependent sex determination. One group of eggs was incubated at 26.5°C to produce males. Another group of eggs was incubated at 26.5°C until embryos reached stage 17; eggs were then shifted to 31°C for 6 days to produce females, and returned to 26.5°C for the rest of embryogenesis. Thus, males and females were at the same temperature when autonomic tone was determined and for most of development. Cholinergic blockade increased resting blood pressure (P(m)) and heart rate (f(H)) in both sexes at 75% and 90% of incubation. However, the magnitude of the f(H) response was enhanced in males compared with females at 90% of incubation. β-adrenergic blockade increased P(m) at 75% of incubation in both sexes but had no effect at 90% of incubation. β-adrenergic blockade reduced f(H) at both time points but produced a stronger response at 90% versus 75% of incubation. We found that α-adrenergic blockade decreased P(m) in both sexes at 75% and 90% of incubation and decreased f(H) at 75% of incubation in both sexes. At 90% of incubation, f(H) decreased in females but not males. Although these data clearly demonstrate sexual dimorphism in the autonomic regulation of cardiovascular physiology in embryos, further studies are needed to test whether differences are caused by endocrine signals from gonads or by a hormone-independent temperature effect.

Analysis of ovary-specific genes in relation to egg maturation and female nutritional condition in the mosquitoes Georgecraigius atropalpus and Aedes aegypti (Diptera: Culicidae)

PubMed Central

Telang, Aparna; Rechel, Julie A.; Brandt, Jessica R.; Donnell, David M.

2013-01-01

Analysis of the reproductive physiology of anautogenous mosquitoes at the molecular level is complicated by the simultaneity of ovarian maturation and the digestion of a blood meal. In contrast to anautogenous mosquitoes, autogenous female mosquitoes can acquire greater nutrient stores as larvae and exhibit higher ovarian production of ecdysteroids at adult eclosion. These features essentially replace the role of a blood meal in provisioning the first batch of eggs and initiating egg development. To gain insight into the process of ovary maturation we first performed a transcript analysis of the obligatory autogenous mosquito Georgecraigius atropalpus (formerly Ochlerotatus atropalpus). We identified ESTs using suppressive subtractive hybridization (SSH) of transcripts from ovaries at critical times during oogenesis in the absence of blood digestion. Preliminary expression studies of genes such as apolipophorin III (APO) and oxysterol binding protein (OSBP) suggested these genes might be cued to female nutritional status. We then applied our findings to the medically important anautogenous mosquito Aedes aegypti. RNAi-based analyses of these genes in Ae. aegypti revealed a reduction in APO transcripts leads to reduced lipid levels in carcass and ovaries and that OSBP may play a role in overall lipid and sterol homeostasis. In addition to expanding our understanding of mosquito ovarian development, the continued use of a comparative approach between autogenous and anautogenous species may provide novel intervention points for the regulation of mosquito egg production. PMID:23238126

Analysis of ovary-specific genes in relation to egg maturation and female nutritional condition in the mosquitoes Georgecraigius atropalpus and Aedes aegypti (Diptera: Culicidae).

PubMed

Telang, Aparna; Rechel, Julie A; Brandt, Jessica R; Donnell, David M

2013-03-01

Analysis of the reproductive physiology of anautogenous mosquitoes at the molecular level is complicated by the simultaneity of ovarian maturation and the digestion of a blood meal. In contrast to anautogenous mosquitoes, autogenous female mosquitoes can acquire greater nutrient stores as larvae and exhibit higher ovarian production of ecdysteroids at adult eclosion. These features essentially replace the role of a blood meal in provisioning the first batch of eggs and initiating egg development. To gain insight into the process of ovary maturation we first performed a transcript analysis of the obligatory autogenous mosquito Georgecraigius atropalpus (formerly Ochlerotatus atropalpus). We identified ESTs using suppressive subtractive hybridization (SSH) of transcripts from ovaries at critical times during oogenesis in the absence of blood digestion. Preliminary expression studies of genes such as apolipophorin III (APO) and oxysterol binding protein (OSBP) suggested these genes might be cued to female nutritional status. We then applied our findings to the medically important anautogenous mosquito Aedes aegypti. RNAi-based analyses of these genes in Ae. aegypti revealed a reduction in APO transcripts leads to reduced lipid levels in carcass and ovaries and that OSBP may play a role in overall lipid and sterol homeostasis. In addition to expanding our understanding of mosquito ovarian development, the continued use of a comparative approach between autogenous and anautogenous species may provide novel intervention points for the regulation of mosquito egg production. Copyright © 2012 Elsevier Ltd. All rights reserved.

Betaine is accumulated via transient choline dehydrogenase activation during mouse oocyte meiotic maturation.

PubMed

McClatchie, Taylor; Meredith, Megan; Ouédraogo, Mariame O; Slow, Sandy; Lever, Michael; Mann, Mellissa R W; Zeisel, Steven H; Trasler, Jacquetta M; Baltz, Jay M

2017-08-18

Betaine ( N,N,N -trimethylglycine) plays key roles in mouse eggs and preimplantation embryos first in a novel mechanism of cell volume regulation and second as a major methyl donor in blastocysts, but its origin is unknown. Here, we determined that endogenous betaine was present at low levels in germinal vesicle (GV) stage mouse oocytes before ovulation and reached high levels in the mature, ovulated egg. However, no betaine transport into oocytes was detected during meiotic maturation. Because betaine can be synthesized in mammalian cells via choline dehydrogenase (CHDH; EC 1.1.99.1), we assessed whether this enzyme was expressed and active. Chdh transcripts and CHDH protein were expressed in oocytes. No CHDH enzyme activity was detected in GV oocyte lysate, but CHDH became highly active during oocyte meiotic maturation. It was again inactive after fertilization. We then determined whether oocytes synthesized betaine and whether CHDH was required. Isolated maturing oocytes autonomously synthesized betaine in vitro in the presence of choline, whereas this failed to occur in Chdh -/- oocytes, directly demonstrating a requirement for CHDH for betaine accumulation in oocytes. Overall, betaine accumulation is a previously unsuspected physiological process during mouse oocyte meiotic maturation whose underlying mechanism is the transient activation of CHDH. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Grande Ronde Basin Spring Chinook Salmon Captive Broodstock Program, 2008 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffnagle, Timothy L.; Hair, Donald; Gee, Sally

2009-03-31

The Grande Ronde Basin Spring Chinook Salmon Captive Broodstock Program is designed to rapidly increase numbers of Chinook salmon in stocks that are in imminent danger of extirpation in Catherine Creek (CC), Lostine River (LR) and upper Grande Ronde River (GR). Natural parr are captured and reared to adulthood in captivity, spawned (within stocks) and their progeny reared to smoltification before being released into the natal stream of their parents. This program is co-managed by ODFW, National Marine Fisheries Service, Nez Perce Tribe and Confederated Tribes of the Umatilla Indian Reservation. Presmolt rearing was initially conducted at Lookingglass Fish Hatcherymore » (LFH) but parr collected in 2003 and later were reared at Wallowa Fish Hatchery (WFH). Post-smolt rearing is conducted at Bonneville Fish Hatchery (BOH - freshwater) and at Manchester Research Station (MRS - saltwater). The CC and LR programs are being terminated, as these populations have achieved the goal of a consistent return of 150 naturally spawning adults, so the 2005 brood year was the last brood year collected for theses populations. The Grande Ronde River program continued with 300 fish collected each year. Currently, we are attempting to collect 150 natural parr and incorporate 150 parr collected as eggs from females with low ELISA levels from the upper Grande Ronde River Conventional Hatchery Program. This is part of a comparison of two methods of obtaining fish for a captive broodstock program: natural fish vs. those spawned in captivity. In August 2007, we collected 152 parr (BY 2006) from the upper Grande Ronde River and also have 155 Grande Ronde River parr (BY 2006) that were hatched from eyed eggs at LFH. During 2008, we were unable to collect natural parr from the upper Grande Ronde River. Therefore, we obtained 300 fish from low ELISA females from the upper Grande Ronde River Conventional Program. In October 2008 we obtained 170 eyed eggs from the upper Grande Ronde river Conventional Hatchery Program. We will attempt to collect natural parr in August 2009. This year 752 fish were removed from the captive population: 629 fish survived to gamete production and 123 fish died from various causes prior to spawning. Growth of the Captive Broodstock fish was similar to previous years. The saltwater fish have grown more slowly than those reared in freshwater. A total of 720 fish were sorted as maturing and 629 (87.4%) of them survived to spawn. We collected gametes from 273 females and 350 males from the 2002-2006 brood years in 2008, using 111 spawning matrices and collected 474,187 green eggs (1,737 eggs/female). All ripe males were spawned and no semen was collected for cryo-preservation. Of the 474,187 eggs collected for the BY 2008 F1 generation, 448,373 (94.6%) survived to the eyed stage. 68,612 (15.3%) were culled from females with high ELISA OD values for BKD prevention. For BY 2007, we collected a total of 477,048 eggs from all three populations and 407,369 (85.4%) reached the eyed stage, while 95,024 eyed eggs (23.3%) were culled for BKD prevention. Eyed eggs were hatched at Lookingglass Fish Hatchery, producing 267,131 fry. As parr, 153,371 fish were coded-wire tagged (CWT). For the 2006 F1 brood year, we collected 177,890 eggs and 149,073 (83.8%) reached the eyed stage. 83,826 eyed eggs (56.2%) were culled at the eyed stage for BKD prevention. 61,044 fry were produced (93.6%), 53,688 (88 %) survived to smolt. There were 54 bacterial kidney disease (BKD) mortalities at BOH and MRS, combined in this reporting period. Overall, there were fewer BKD mortalities in 2008 due to a reduced number of fish coming into the Captive Broodstock Program and a shift away from collecting wild parr to using eyed eggs from low ELISA females from the Conventional Hatchery Program. Unknown causes of death accounted for 32 deaths at MRS and BOH, combined in 2008. We continually examine and modify the operations of the Captive Broodstock Program to make improvements wherever possible. We continue to have difficulty with prevention and treatment of BKD outbreaks and continue to use erythromycin and azithromycin to treat this disease. We are also continuing to investigate other possible treatments and prophylactic measures. To reduce the incidence of BKD in offspring of the Captive Broodstock Program, we continue to allow culling of eyed eggs from females with high BKD ELISA values (generally >0.800 OD units but the cull level varies annually, depending on the distribution of ELISA values, number of eggs collected, and management considerations). We are also using ultrasound to determine maturity and sex of fish early in the maturation process and are now able to determine maturity and sex of most maturing fish in early April. This allows us to transfer maturing fish from saltwater to freshwater at a more natural time, which should improve fecundity and egg quality of saltwater-reared fish.« less

Blood clots in the cumulus-oocyte complex predict poor oocyte quality and post-fertilization development.

PubMed

Ebner, T; Moser, M; Shebl, O; Sommergruber, M; Yaman, C; Tews, G

2008-06-01

Assessment of oocyte maturity and quality (morphological appearance) at the time of retrieval is difficult as the egg is obscured by a large cumulus mass that hinders adequate scoring. Since no data are available on the possible relationship between the cumulus-oocyte complex (COC) and oocyte morphology, this prospective intracytoplasmic sperm injection study was set up in 87 consecutive patients. COC were grouped according to expansion of both corona radiata and cumulus matrix. Special emphasis was placed on recording morphological anomalies of COC (inclusion of blood clots and amorphous clumps). For all mature ovae, quality was assessed and preimplantation development followed up to blastocyst stage if fertilized. The risk of not harvesting an oocyte was higher in COC with blood clots compared with normal cumulus matrices (P = 0.004). COC expansion did not allow for prediction of either nuclear status or quality of the egg. The presence of blood clots within the cumulus matrix was associated with reduced oocyte quality (dense central granulation), fertilization rate and blastocyst formation, compared with unaffected COC (P < 0.05). It may be postulated that COC showing blood inclusions derive from poor quality follicles, which has a detrimental effect on oocyte quality and further cleavage to blastocyst stage. Consequently, mechanical removal of blood clots cannot rescue the corresponding embryo.

Spawning strategy in Atlantic bobtail squid Sepiola atlantica (Cephalopoda: Sepiolidae)

NASA Astrophysics Data System (ADS)

Rodrigues, Marcelo; Garcí, Manuel E.; Troncoso, Jesús S.; Guerra, Ángel

2011-03-01

This study aimed to determine the spawning strategy in the Atlantic bobtail squid Sepiola atlantica, in order to add new information to the knowledge of its reproductive strategy. A total of 12 females that spawned in aquaria were examined. Characteristics of the reproductive traits and egg clutches were similar to those of other known Sepiolidae. Clutch size varied from 31 up to 115 eggs. Females of this species had incorporated up to 1.58 times of their body weight into laid eggs. The size of laid eggs showed a positive correlation with maternal body size, supporting the idea that female size is a determinant of egg size. Our data suggest that S. atlantica is an intermittent terminal spawner , and that its spawning strategy comprises group-synchronous ovary maturation, multiple egg laying, and deposition of egg clutches in different locations. The obtained data provide insights for future comparative studies on reproductive allocation.

[Elucidation of the mechanism of fertilization and clinical application of assisted reproductive technology].

PubMed

Hiroi, M

1996-08-01

Fertilization is the process including many events such as maturation of egg and sperm, attachment, binding, acrosomal reaction, penetration, fusion, cortical reaction, zona reaction and nuclear fusion of both gamete, whereby individual gametes from the female and male unite to create offspring. Although the reason for mechanism of fertilization is still not clearly understood, this process may accelerate the rate adaptation in evolution. In this special lecture, I would like to present our experimental and clinical results especially concerning with morphological, physiological, biochemical and molecular approach on the mechanism of fertilization. 1. Development and maturation of follicles and oocytes. It is well known that pituitary FSH, LH control the ovarian function. Follicular development and ovum maturation are also controlled by both pituitary gonadotropins and local factors such as autocrine and paracrine agents. When hMG is injected during 1-6 day of menstrual cycle, several dominant follicles are developed. If hMG is injected after selection of dominant follicles, only one dominant follicle develop in the ovary. When PMS-treated immature rats were injected with immature or mature follicle fluids, rats injected with mature follicular fluid showed strongly suppress in the ovarian weights and numbers of ovulated follicles. Also mature follicle suppress aromatization from and androstenedione to estradiol. These findings mean that mature follicular fluid contains inhibitory factors. Apoptosis of granulosa cells and follicular steroids are related to fertilization. 2. Intracellular calcium of oocyte. Intracellular calcium concentration is known to start to increase in a periodic manner after fertilization in oocytes of mammalians. In 65% of tested mouse oocytes, fertilization occurred during 4 hours observation after sperm insemination in vitro. An initial long lasting intracellular calcium concentration was observed and followed by periodic manner. This calcium oscillation is inhibited by calcium blockers such as verpamil and nifedipine, but increased by high concentration of extracellular calcium concentration in the medium. Role of increase of intracellular calcium are understood to prevent polysperm and activate metabolism of oocytes. 3. Glucose metabolism of oocytes. Mouse embryo utilizes pyruvate as an essential nutrient until the 8-cell stage, and glucose thereafter. We have devised non-radiometrie and enzymatic microassay method to measure glucose, deoxyglucose, deoxyglucose 6-phosphate incorporated into individual mouse oocytes and preimplantation embryo. In parallel, the activities of several enzymes of glycolytic pathway were also determined. In this study, glucose metabolism is necessary to develop in fertilized ova with changing activity of enzymes. 4. Molecular bases of ovarian fluid. The zona pellucida ZP is involved in a number of events in fertilization, all these fertilization events occur in the oviduct. Oviductal glycoprotein 200-240 KD has been identified from oviductal zona pellucida. Monoclonal antibody of oviductal glycoprotein reacted with ZP of oviductal egg but not with the ovarian egg. Anti-ZPO antibody inhibit to bind sperm to ZP. Sequences in mouse and hamster oviduct specific glycoprotein are estimated, this glycoprotein mRNA was observed in only oviduct by northern blotting method. These molecular gene expression was observed by in situ hybridization in the oviduct of estrous cycle of hamster. 5. Microinsemination of sperm. Microinsemination of sperm into oocyte is widely used in clinical medicine. Sperm penetration assay (hamster test) is useful method to estimate fertilization capacity of sperm. But immotile sperm cannot estimate it. So modified micro sperm penetration assay was established to estimate fertilization capacity of sperm by using micro-manipulator. Subzonal sperm injection (SUZI) and intracytoplasmic sperm injection (ICSI) promotes fertilization and cleavage rate in immotile

MicroRNA-276 promotes egg-hatching synchrony by up-regulating brm in locusts

PubMed Central

He, Jing; Chen, Qianquan; Wei, Yuanyuan; Jiang, Feng; Yang, Meiling; Hao, Shuguang; Guo, Xiaojiao; Chen, Dahua; Kang, Le

2016-01-01

Developmental synchrony, the basis of uniform swarming, migration, and sexual maturation, is an important strategy for social animals to adapt to variable environments. However, the molecular mechanisms underlying developmental synchrony are largely unexplored. The migratory locust exhibits polyphenism between gregarious and solitarious individuals, with the former displaying more synchronous sexual maturation and migration than the latter. Here, we found that the egg-hatching time of gregarious locusts was more uniform compared with solitarious locusts and that microRNA-276 (miR-276) was expressed significantly higher in both ovaries and eggs of gregarious locusts than in solitarious locusts. Interestingly, inhibiting miR-276 in gregarious females and overexpressing it in solitarious females, respectively, caused more heterochronic and synchronous hatching of progeny eggs. Moreover, miR-276 directly targeted a transcription coactivator gene, brahma (brm), resulting in its up-regulation. Knockdown of brm not only resulted in asynchronous egg hatching in gregarious locusts but also impaired the miR-276–induced synchronous egg hatching in solitarious locusts. Mechanistically, miR-276 mediated brm activation in a manner that depended on the secondary structure of brm, namely, a stem-loop around the binding site of miR-276. Collectively, our results unravel a mechanism by which miR-276 enhances brm expression to promote developmental synchrony and provide insight into regulation of developmental homeostasis and population sustaining that are closely related to biological synchrony. PMID:26729868

Comparative reproductive biology of three dominant myctophids of the genus Diaphus on the slope region of the East China Sea

NASA Astrophysics Data System (ADS)

Sassa, Chiyuki; Tanaka, Hiroshige; Ohshimo, Seiji

2016-09-01

We examined the reproductive biology of three dominant pseudoceanic myctophids, Diaphus garmani, D. chrysorhynchus, and D. watasei, on the slope region of the East China Sea. Overall, females were more abundant in D. garmani and D. chrysorhynchus, while males were more abundant in D. watasei. The gonadosomatic index (GSI) at 50% sexual maturity of females of D. garmani, D. chrysorhynchus, and D. watasei was 3.65, 3.92, and 6.27, respectively. Based on these criteria, females of each species can mature at sizes larger than 42, 71, and 120 mm standard length (SL), respectively. In all three species, GSI of females showed high values during summer, i.e. the primary spawning season, and occurrence of females with hydrated ovaries was restricted to the daytime (0600-1530 h) in the mesopelagic layer of 270-450 m depth. Oocytes at various sizes were found in mature ovaries, indicating that they are multiple spawners. Spawning frequencies were estimated to be approximately 3-9 days. Mean egg size at hydration and batch fecundity was respectively smallest and lowest in D. garmani (0.60 mm and 612-2200 eggs) and largest and highest in D. watasei (0.65 mm and 10,356-44,879 eggs). Batch fecundity increased linearly with SL in all species, with a steeper slope in D. watasei. Diaphus garmani is characterized by early maturation at a smaller size, while D. watasei channels a larger part of the energy budget into somatic growth during the juvenile and later immature stages (<120 mm SL) than the other two species and subsequently reproduces at a larger size as mature adults.

Cell Death and Reproductive Regression in Female Schistosoma mansoni

PubMed Central

Galanti, Sarah E.; Huang, Stanley Ching-Cheng; Pearce, Edward J.

2012-01-01

The vitellarium is a highly proliferative organ, producing cells which are incorporated along with a fertilized ovum into the schistosome egg. Vitellarial growth fails to occur in virgin female schistosomes in single sex (female-only) infections, and involution of this tissue, which is accompanied by physical shrinkage of the entire worm, occurs when mature females sexually regress upon removal from their male partners. We have found that upon removal from their hosts into tissue culture, female parasites regress whether they are mated or not, but that cessation of egg production and a decline in expression of the vitelline gene p14 is delayed by mating. We used BrdU labeling to investigate whether there was a loss of proliferation in the vittelarium that might account for regression and found that the proliferation rate declined equally in paired and singled females once placed into culture. However, TUNEL staining and Caspase 3 activity measurements indicate that the loss of vitrellarial cellularity associated with regression is associated with profound apoptotic vitelline cell death, which is not apparent in the vitellaria of paired females immediately ex vivo, and which develops in vitro regardless of whether males are present or not. Furthermore, primordial vitellaria in virgin females have a high frequency of apoptotic cells but are characterized by a proliferation rate that is indistinguishable from that in fully developed vitellaria in mature paired females. Taken together, our data suggest that the vitelline proliferation rate is independent of pairing status. In contrast, the survival of vitelline cells, and therefore the development of the vitellarium, is highly male-dependent. Both processes are negatively affected by removal from the host regardless of whether male worms are present or not, and are unsustainable using standard tissue culture approaches. PMID:22363825

[Comparison of human chorionic gonadotropin (Pregnyl 10 000 IU i.m.) versus GnRH agonist (triptorelin 0,2 mg s.c.) for final oocytes maturation in the same egg donors--clinical and embryological characteristics].

PubMed

Streda, R; Mardesic, T; Sobotka, V; Koryntová, D; Hybnerová, L; Jindra, M; Paseková, V; Slámová, J; Stevíková, M; Voboril, J; Jelínková, L; Vilímová, S; Ichová, J; Mádrová, J; Tersová, H; Masata, M; Sobotková, J

2011-04-01

To compare clinical and embryological characteristics in donor cycles triggered for final oocytes maturation with Pregnyl 10 000 IU i.m. versus triptorelin 0.2 mg s.c. in the same patients in two sequential stimulation cycles. The aim of the study is to decrease the risk of the development of ovarian hyperstimulation syndrome (OHSS) at high response donors by the replacement of Pregnyl 10 000 IU i.m. vs. triptorelin 0.2 mg s.c. The administration of a single dose of gonadotropin-releasing hormone agonist (triptorelin 0.2 mg s.c.) induces release of LH from the pituitary gland similarly to a spontaneous LH surge. Prospective cross-over trial. Sanatorium Pronatal, Praha. From August 2009 to July 2010 we analysed 24 stimulation cycles in 12 egg donors treated with GnRH antagonist protocol with recombinant FSH (follitropin beta). We identified patients with more than 15 follicles during examination by transvaginal ultrasound. When at least 3 leading follicles reached 17 mm in diameter we administrated Pregnyl 10 000 IU i.m. for final oocytes maturation and triptorelin 0.2 mg s.c in the subsequent treatment cycle. The primary outcome measure was number of oocytes, proportion mature oocytes and fertilized oocytes. The secondary outcome were duration of FSH stimulation, total dose of gonadotropins and mean daily dose of gonadotropins. Data was analysed by paired t-test. We retrieved 17.2 +/- 8.6 vs. 15.8 +/- 5.3 (ns) oocytes, 12.6 +/- 7.3 vs. 13.0 +/- 5.4 (ns) metaphase II oocytes, proportion of metaphase II oocytes (%) was 73 vs. 83 (ns), number of fertilized oocytes 11.5 +/- 6.7 vs. 11.7 +/- 4.5 (ns), fertilization rate (%) 91 vs. 90 (ns) in Pregnyl's vs. triptorelin's group, resp. Duration of FSH stimulation (days) 12.2 +/- 0.8 vs. 12.4 +/- 0.7 (ns), total dose of gonadotropins (IU) 1744 +/- 277 vs. 1740 +/- 276 (ns), mean daily dose of gonadotropins (IU) 238 +/- 43 vs. 221 +/- 36 (ns), were not statistically different in both groups. Number of mature oocytes and subsequent embryonic cleavage is comparable to standard hCG treatment. There are no differences in clinical and embryological characteristics in both groups. Only one patient with administration of Pregnyl 10 000 IU i.m. was treated for OHSS grade II by vaginal paracentesis. Administration of triptorelin 0.2 mg s.c. is a safe and effective approach to achieve mature oocytes in egg donation programme, where we do not take care of implantation, which has got some limitations based on several studies.

Growth, reproduction & population structure of the freshwater crab Sinopotamon yangtsekiense bott, 1967, from Zhejiang, China

NASA Astrophysics Data System (ADS)

Chen, Tao; Lai, Wei; Du, Nan-Shan

1994-03-01

Monthly investigations were mae on the population of Chinese freshwater crab, Sinopotamon yangtsekiense Bott, 1967 from April, 1984 to March, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature. During the April to November growth period, the crabs' major development occurred from June through October. One year was required for a fine white oocyte to develop into a mature egg. The reproduction period was June October. Females bearing eggs were taken from June August, and crabs with young were found from July October. The females reproduced once a year but could for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from 30 to 100 eggs. New-born crabs become mature after 1 2 years. The sex ratio was approximately 1∶1 in the overall population. However, the larger crabs are predominantly male. The age distribution of S. yangtsekinese was estimated from size frequency histograms. There were more adult crabs (over 70%) from June to October and more immature crabs (over 50%) from November to May.

Intake of Erythrocytes Required for Reproductive Development of Female Schistosoma japonicum.

PubMed

Wang, Jipeng; Wang, Shuqi; Liu, Xiufeng; Xu, Bin; Chai, Riyi; Zhou, Pan; Ju, Chuan; Sun, Jun; Brindley, Paul J; Hu, Wei

2015-01-01

The reproductive development and maturation of female schistosomes are crucial since their released eggs are responsible for the host immunopathology and transmission of schistosomiasis. However, little is known about the nutrients required by female Schistosoma japonicum during its sexual maturation. We evaluated the promoting effect of several nutrients (calf serum, red blood cells (RBCs), ATP and hypoxanthine) on the reproductive development of pre-adult females at 18 days post infection (dpi) from mixed infections and at 50 dpi from unisexual infections of laboratory mice in basic medium RPMI-1640. We found RBCs, rather than other nutrients, promoted the female sexual maturation and egg production with significant morphological changes. In 27% of females (18 dpi) from mixed infections that paired with males in vitro on day 14, vitelline glands could be positively stained by Fast Blue B; and in 35% of females (50 dpi) from unisexual infections on day 21, mature vitelline cells were observed. Infertile eggs were detected among both groups. To analyze which component of mouse RBCs possesses the stimulating effect, RBCs were fractionated and included in media. However, the RBC fractions failed to stimulate development of the female reproductive organs. In addition, bovine hemoglobin hydrolysate, digested by neutral protease, was found to exhibit the promoting activity instead of untreated bovine hemoglobin. The other protein hydrolysate, lactalbumin hydrolysate, exhibited a similar effect with bovine hemoglobin hydrolysate. Using quantitative RT-PCR, we found the expression levels of four reproduction-related genes were significantly stimulated by RBCs. These data indicate that RBCs provide essential nutrients for the sexual maturation of female S. japonicum and that the protein component of RBCs appeared to constitute the key nutrient. These findings would improve laboratory culture of pre-adult schistosomes to adult worms in medium with well-defined components, which is important to investigate the function of genes related to female sexual maturation.

Intake of Erythrocytes Required for Reproductive Development of Female Schistosoma japonicum

PubMed Central

Wang, Jipeng; Wang, Shuqi; Liu, Xiufeng; Xu, Bin; Chai, Riyi; Zhou, Pan; Ju, Chuan; Sun, Jun; Brindley, Paul J.; Hu, Wei

2015-01-01

The reproductive development and maturation of female schistosomes are crucial since their released eggs are responsible for the host immunopathology and transmission of schistosomiasis. However, little is known about the nutrients required by female Schistosoma japonicum during its sexual maturation. We evaluated the promoting effect of several nutrients (calf serum, red blood cells (RBCs), ATP and hypoxanthine) on the reproductive development of pre-adult females at 18 days post infection (dpi) from mixed infections and at 50 dpi from unisexual infections of laboratory mice in basic medium RPMI-1640. We found RBCs, rather than other nutrients, promoted the female sexual maturation and egg production with significant morphological changes. In 27% of females (18 dpi) from mixed infections that paired with males in vitro on day 14, vitelline glands could be positively stained by Fast Blue B; and in 35% of females (50 dpi) from unisexual infections on day 21, mature vitelline cells were observed. Infertile eggs were detected among both groups. To analyze which component of mouse RBCs possesses the stimulating effect, RBCs were fractionated and included in media. However, the RBC fractions failed to stimulate development of the female reproductive organs. In addition, bovine hemoglobin hydrolysate, digested by neutral protease, was found to exhibit the promoting activity instead of untreated bovine hemoglobin. The other protein hydrolysate, lactalbumin hydrolysate, exhibited a similar effect with bovine hemoglobin hydrolysate. Using quantitative RT-PCR, we found the expression levels of four reproduction-related genes were significantly stimulated by RBCs. These data indicate that RBCs provide essential nutrients for the sexual maturation of female S. japonicum and that the protein component of RBCs appeared to constitute the key nutrient. These findings would improve laboratory culture of pre-adult schistosomes to adult worms in medium with well-defined components, which is important to investigate the function of genes related to female sexual maturation. PMID:25978643

Effect of 17β-trenbolone on male and female reproduction in Japanese quail (Coturnix japonica)

USGS Publications Warehouse

Henry, Paula F.P.; Akuffo, Valorie G.; Chen, Yu; Karouna-Renier, Natalie K.; Sprague, Daniel T.; Bakst, Murray R.

2012-01-01

The anabolic steroid 17β trenbolone (17β-TB), a known endocrine disrupting chemical, may influence reproductive functions in avian wildlife. We evaluated the effects of dietary exposure to 17β-TB at 5 and 20 ppm on reproductive functional endpoints in Japanese quail during and after sexual maturation. In the male, 5 and 20 ppm treatments revealed no differences in body and testes weight, testes histology, plasma testosterone concentrations, or size and weight of the foam glands. However, the onset of foam production was significantly earlier (days of age) in the 20 ppm males. In females, dietary 17β-TB at 20 ppm caused a reduction in the number of maturing yellow yolk follicles and overall egg production. Plasma testosterone concentrations were reduced compared to controls. Histology of the oviductal sperm storage tubules was normal in all treatments. The number of sperm holes, sites on the perivitelline layer (PVL) where sperm bound and hydrolyzed a path through the PVL, was significantly greater in the 10th egg laid compared to the 1st egg laid in the 20 ppm treatment. Potential effects, albeit transient, on endpoints associated with male maturation warrant further investigation into the sensitivity of these measures in the event of embryonic and/or trans-generational exposure to 17β-TB.

Life history of the Glanville fritillary butterfly in fragmented versus continuous landscapes

PubMed Central

Duplouy, Anne; Ikonen, Suvi; Hanski, Ilkka

2013-01-01

Habitat loss and fragmentation threaten the long-term viability of innumerable species of plants and animals. At the same time, habitat fragmentation may impose strong natural selection and lead to evolution of life histories with possible consequences for demographic dynamics. The Baltic populations of the Glanville fritillary butterfly (Melitaea cinxia) inhabit regions with highly fragmented habitat (networks of small dry meadows) as well as regions with extensive continuous habitat (calcareous alvar grasslands). Here, we report the results of common garden studies on butterflies originating from two highly fragmented landscapes (FL) in Finland and Sweden and from two continuous landscapes (CL) in Sweden and Estonia, conducted in a large outdoor cage (32 by 26 m) and in the laboratory. We investigated a comprehensive set of 51 life-history traits, including measures of larval growth and development, flight performance, and adult reproductive behavior. Seventeen of the 51 traits showed a significant difference between fragmented versus CL. Most notably, the growth rate of postdiapause larvae and several measures of flight capacity, including flight metabolic rate, were higher in butterflies from fragmented than CL. Females from CL had shorter intervals between consecutive egg clutches and somewhat higher life-time egg production, but shorter longevity, than females from FL. These results are likely to reflect the constant opportunities for oviposition in females living in continuous habitats, while the more dispersive females from FL allocate more resources to dispersal capacity at the cost of egg maturation rate. This study supports theoretical predictions about small population sizes and high rate of population turnover in fragmented habitats selecting for increased rate of dispersal, but the results also indicate that many other life-history traits apart from dispersal are affected by the degree of habitat fragmentation. PMID:24455144

Are all eggs created equal? A case study from the Hawaiian reef-building coral Montipora capitata

NASA Astrophysics Data System (ADS)

Padilla-Gamiño, Jacqueline L.; Bidigare, Robert R.; Barshis, Daniel J.; Alamaru, Ada; Hédouin, Laetitia; Hernández-Pech, Xavier; Kandel, Frederique; Leon Soon, Sherril; Roth, Melissa S.; Rodrigues, Lisa J.; Grottoli, Andrea G.; Portocarrero, Claudia; Wagenhauser, Stephanie A.; Buttler, Fenina; Gates, Ruth D.

2013-03-01

Parental effects have been largely unexplored in marine organisms and may play a significant role in dictating the phenotypic range of traits in coral offspring, influencing their ability to survive environmental challenges. This study explored parental effects and life-stage differences in the Hawaiian reef-building coral Montipora capitata from different environments by examining the biochemical composition of mature coral colonies and their eggs. Our results indicate that there are large biochemical differences between adults and eggs, with the latter containing higher concentration of lipids (mostly wax esters), ubiquitinated proteins (which may indicate high turnover rate of proteins) and antioxidants (e.g., manganese superoxide dismutase). Adults displayed high phenotypic plasticity, with corals from a high-light environment having more wax esters, lighter tissue δ13C signatures and higher Symbiodinium densities than adults from the low-light environment who had higher content of accessory pigments. A green-algal pigment (α-carotene) and powerful antioxidant was present in eggs; it is unclear whether this pigment is acquired from heterotrophic food sources or from endolithic green algae living in the adult coral skeletons. Despite the broad phenotypic plasticity displayed by adults, parental investment in the context of provisioning of energy reserves and antioxidant defense was the same in eggs from the different sites. Such equality in investment maximizes the capacity of all embryos and larvae to cope with challenging conditions associated with floating at the surface and to disperse successfully until an appropriate habitat for settlement is found.

Reproductive toxicity assessment of benzo[a]pyrene in the marine polychaete Perinereis nuntia

NASA Astrophysics Data System (ADS)

Wu, Qingyang; Wang, Shuqi; Chen, Xiaopeng; Li, Ping

2017-07-01

Benzo[a]pyrene (B[a]P) is an increasingly present marine environmental pollutant, yet our understanding of the long-term consequences of reproductive toxicity in marine benthic polychaetes remains limited. To test the reproductive toxicity of B[a]P on polychaetes, Perinereis nuntia was exposed to B[a]P-contaminated artificial seawater and sexual maturation, the sex ratio, number of eggs spawned, fertilization and hatching rated, as well as vitellogenin (VTG) mRNA expression levels were analyzed. A low concentration of B[a]P (2.5 μg/L) had no effects on the rate of sexual maturation, spawning, or fertilization but significantly increased the sex ratio (female: male) from 1.6±0.15:1 to 2.3±0.18:1, inhibited hatching rate by 27%, and significantly increased VTG mRNA expression level by 3.7-fold following a 60-day exposure, compared with those in the solvent controls. A higher concentration of B[a]P (25 μg/L) caused more serious effects; sexual maturation, fertilization success, and hatching decreased by 31%, 17% and 46%, respectively, and the sex ratio (female: male) and VTG mRNA gene expression level increased by 54% and 7.1-fold, respectively. These results demonstrate that sublethal concentrations of B[a]P negatively affect reproductive performance of the sandworm P. nuntia.

Origin, differentiation and functional ultrastructure of egg envelopes in the cestode Echinococcus multilocularis Leuckart, 1863 (Cyclophyllidea: Taeniidae).

PubMed

Świderski, Zdzisław; Miquel, Jordi; Azzouz-Maache, Samira; Pétavy, Anne-Françoise

2017-07-01

The origin, differentiation and functional ultrastructure of oncospheral or egg envelopes in Echinococcus multilocularis Leuckart, 1863 were studied by transmission electron microscopy (TEM) and cytochemistry. The purpose of our study is to describe the formation of the four primary embryonic envelopes, namely vitelline capsule, outer envelope, inner envelope and oncospheral membrane, and their transformation into the oncospheral or egg envelopes surrounding the mature hexacanth. This transformation takes place in the preoncospheral phase of embryonic development. The vitelline capsule and oncospheral membrane are thin membranes, while the outer and inner envelopes are thick cytoplasmic layers formed by two specific types of blastomeres: the outer envelope by cytoplasmic fusion of two macromeres and the inner envelope by cytoplasmic fusion of three mesomeres. Both outer and inner envelopes are therefore cellular in origin and syncytial in nature. During the advanced phase of embryonic development, the outer and inner envelopes undergo great modifications. The outer envelope remains as a metabolically active layer involved in the storage of glycogen and lipids for the final stages of egg development and survival. The inner envelope is the most important protective layer because of its thick layer of embryophoric blocks that assures oncospheral protection and survival. This embryophore is the principal layer of mature eggs, affording physical and physiological protection for the differentiated embryo or oncosphere, since the outer envelope is stripped from the egg before it is liberated. The embryophore is very thick and impermeable, consisting of polygonal blocks of an inert keratin-like protein held together by a cementing substance. The embryophore therefore assures extreme resistance of eggs, enabling them to withstand a wide range of environmental temperatures and physicochemical conditions.

Correlated responses to selection for increased intramuscular fat in a Chinese quality chicken line.

PubMed

Zhao, G P; Chen, J L; Zheng, M Q; Wen, J; Zhang, Y

2007-11-01

The correlated response in traits encompassing meat quality, carcass, sexual maturity, egg production, and egg quality traits arising from selection for increased intramuscular fat (IMF) content of breast muscle were investigated in the fifth generation of a selection experiment including a line (F) selected for increased IMF and a randombred control line (C). The results showed that breast muscle IMF content in the F line (4.25%) was significantly higher (P < 0.001) than that in the C line (3.80%) after 5 generations of selection. The same trend was observed in IMF content in thigh muscle (20.03 vs. 19.41%, P < 0.05). The shear force of breast muscle in the F line was lower than that in the C line (1.82 vs. 2.12 kg, P < 0.01), whereas increases occurred in BW (P < 0.05), carcass weight (P < 0.05), breast muscle weight (P < 0.001), breast muscle percentage of live weight (P < 0.05), abdominal fat weight (P < 0.001), ovarian weight at 90 d of age (P < 0.05), and egg weight (P < 0.05) in the F line, relative to the C line. Age at first lay in the F line was 4.84 d earlier than that in the C line (P < 0.001). No differences were found between the 2 lines (P > 0.05) in the following traits: drip loss, meat color (L*, a*, and b*), carcass percentage, thigh muscle weight, thigh muscle percentage, abdominal fat percentage, first egg weight, egg number (until 43 wk), Haugh units, shell thickness, and egg shape. The results of the present study demonstrated that selection for breast muscle IMF leads to desirable changes in meat quality, carcass, sexual maturity, and egg production traits.

Egg production of turbot, Scophthalmus maximus, in the Baltic Sea

NASA Astrophysics Data System (ADS)

Nissling, Anders; Florin, Ann-Britt; Thorsen, Anders; Bergström, Ulf

2013-11-01

In the brackish water Baltic Sea turbot spawn at ~ 6-9 psu along the coast and on offshore banks in ICES SD 24-29, with salinity influencing the reproductive success. The potential fecundity (the stock of vitellogenic oocytes in the pre-spawning ovary), egg size (diameter and dry weight of artificially fertilized 1-day-old eggs) and gonad dry weight were assessed for fish sampled in SD 25 and SD 28. Multiple regression analysis identified somatic weight, or total length in combination with Fulton's condition factor, as main predictors of fecundity and gonad dry weight with stage of maturity (oocyte packing density or leading cohort) as an additional predictor. For egg size, somatic weight was identified as main predictor while otolith weight (proxy for age) was an additional predictor. Univariate analysis using GLM revealed significantly higher fecundity and gonad dry weight for turbot from SD 28 (3378-3474 oocytes/g somatic weight) compared to those from SD 25 (2343 oocytes/g somatic weight), with no difference in egg size (1.05 ± 0.03 mm diameter and 46.8 ± 6.5 μg dry weight; mean ± sd). The difference in egg production matched egg survival probabilities in relation to salinity conditions suggesting selection for higher fecundity as a consequence of poorer reproductive success at lower salinities. This supports the hypothesis of higher size-specific fecundity towards the limit of the distribution of a species as an adaptation to harsher environmental conditions and lower offspring survival probabilities. Within SD 28 comparisons were made between two major fishing areas targeting spawning aggregations and a marine protected area without fishing. The outcome was inconclusive and is discussed with respect to potential fishery induced effects, effects of the salinity gradient, effects of specific year-classes, and effects of maturation status of sampled fish.

Sex steroid levels, oocyte maturation and spawning performance in Waigieu seaperch (Psammoperca waigiensis) exposed to thyroxin, human chorionic gonadotropin, luteinizing hormone releasing hormone and carp pituitary extract.

PubMed

Pham, Hung Quoc; Nguyen, Anh Tuong; Nguyen, Mao Dinh; Arukwe, Augustine

2010-02-01

In the present study, we have investigated the sex steroid hormone levels, oocyte maturation and spawning performance in Waigieu seaperch (Psammoperca waigiensis) exposed to different doses (0, (control), 0.05, 0.25 and 0.5 mg/kg fish) of thyroxin (T(4)) both through diet (continuously) and injection (single injection). In addition, we also studied plasma steroid hormone levels and spawning performances in female fish injected with a single dose of D-Ala(6), Pro(9)-Net-mGnRH (LHRHa: 50 microg/kg), human chronic gonadotropin (HCG: 1,500 IU/kg) and carp pituitary extract (CPE: 10 mg/kg). In all experiments, samples were collected at 0, 6, 12, 24 and 48 h after exposure. T4 exposure via dietary route produced differential and enhanced effects, compared with when the compound was injected to the broodstock. A significant association between exposure to dietary T4, elevated plasma steroid hormone levels, maturation-, spawning-, fertilization- and hatching rate, egg diameter, embryogenesis and larval growth were observed. Interestingly, we observed that broodstock groups fed with T4 doses spawned 20 days earlier than the control group. Thus, we propose that these differences may be attributed to higher systemic availability of T4 due to dietary exposure that is easily transferable to eggs and embryos, as opposed to injection that require absorption to increase bioavailability. Furthermore, our results show that LHRHa, CPE and HCG produced significant increase in spawning rate, but significantly reduced fertilization- and hatching rates. Waigieu seaperch is a new candidate for marine aquaculture in Vietnam and relatively little is known about the reproductive biology and endocrinology of this species. Therefore, the present study forms an integral basis for understanding the reproductive endocrinology of a tropical marine finfish with increasing aquaculture prospects and may also contribute in the development of sustainable aquaculture of this species in a developing country such as Vietnam. 2009 Elsevier Inc. All rights reserved.

Effect of microwave exposure on the ovarian development of Drosophila melanogaster.

PubMed

Panagopoulos, Dimitris J

2012-06-01

In the present experiments the effect of GSM radiation on ovarian development of virgin Drosophila melanogaster female insects was studied. Newly emerged adult female flies were collected and divided into separate identical groups. After the a lapse of certain number of hours-different for each group-the insects (exposed and sham-exposed) were dissected and their intact ovaries were collected and photographed under an optical microscope with the same magnification. The size of the ovaries was compared between exposed and sham-exposed virgin female insects, during the time needed for the completion of oogenesis and maturation of the first eggs in the ovarioles. Immediately after the intact ovaries were photographed, they were further dissected into individual ovarioles and treated for TUNEL and acridine-orange assays to determine the degree of DNA damage in the egg chamber cells. The study showed that the ovarian size of the exposed insects is significantly smaller than that of the corresponding sham-exposed insects, due to destruction of egg chambers by the GSM radiation, after DNA damage and consequent cell death induction in the egg chamber cells of the virgin females as shown in previous experiments on inseminated females. The difference in ovarian size between sham-exposed and exposed virgin female flies becomes most evident 39-45 h after eclosion when the first eggs within the ovaries are at the late vitellogenic and post-vitellogenic stages (mid-late oogenesis). More than 45 h after eclosion, the difference in ovarian size decreases, as the first mature eggs of the sham-exposed insects are leaving the ovaries and are laid.

Seasonal variation in reproductive traits of the oriental shrimp Palaemon macrodactylus (Crustacea: Caridea: Palaemonidae) in a non-native population

NASA Astrophysics Data System (ADS)

Vázquez, M. Guadalupe; Bas, Claudia C.; Spivak, Eduardo D.

2013-12-01

The magnitude of variations in reproductive traits of Palaemon macrodactylus females throughout a breeding season was studied in a non-native population at Mar del Plata harbor, Argentina. Fecundity, egg size, reproductive output, weight and elemental composition of eggs, and larvae were analyzed in females collected at the beginning, in the mid point, and near the end of a reproductive season and designated as early, middle season, and late females. The highest reproductive output was observed in early females, while the highest fecundity and egg volume occurred in middle season females. Eggs and larvae showed larger body mass in early than in late females. Embryos from early females contained and consumed more carbon during development than embryos from late females, and they also used part of the available nitrogen. Differences in reproduction were observed among the three groups of females. On the one hand, late females matured early but had a poor first reproduction, with few embryos and high egg loss; however, they had longer reproductive life and an enhanced reproductive output in the following season when they became early females. On the other hand, females collected at the midpoint in the reproductive season matured later and had the highest fecundity and egg volume. In addition, larvae with different characteristics resulted from each type of female and were presumably well adapted to the conditions prevailing at the moment they hatched. The extended reproductive period and the diversity of embryos and larvae produced may favor the invading ability of the species.

Egg turning behavior and incubation temperature in Forster’s terns in relation to mercury contamination

USGS Publications Warehouse

Taylor, Gregory T.; Ackerman, Joshua T.; Shaffer, Scott A.

2018-01-01

Egg turning behavior is an important determinant of egg hatchability, but it remains relatively understudied. Here, we examined egg turning rates and egg temperatures in Forster’s terns (Sterna forsteri). We used artificial eggs containing a data logger with a 3-D accelerometer, a magnetometer, and a temperature thermistor to monitor parental incubation behavior of 131 tern nests. Overall, adults turned their eggs an average (±SD) of 3.8 ± 0.8 turns h-1, which is nearly two times higher than that of other seabirds. Egg turning rates increased with nest initiation date. We also examined egg turning rates and egg temperatures in relation to egg mercury contamination. Mercury contamination has been shown to be associated with reduced egg hatchability, and we hypothesized that mercury may decrease egg hatchability via altered egg turning behavior by parents. Despite the high variability in egg turning rates among individuals, the rate of egg turning was not related to mercury concentrations in sibling eggs. These findings highlight the need for further study concerning the potential determinants of egg turning behavior.

Egg turning behavior and incubation temperature in Forster's terns in relation to mercury contamination.

PubMed

Taylor, Gregory T; Ackerman, Joshua T; Shaffer, Scott A

2018-01-01

Egg turning behavior is an important determinant of egg hatchability, but it remains relatively understudied. Here, we examined egg turning rates and egg temperatures in Forster's terns (Sterna forsteri). We used artificial eggs containing a data logger with a 3-D accelerometer, a magnetometer, and a temperature thermistor to monitor parental incubation behavior of 131 tern nests. Overall, adults turned their eggs an average (±SD) of 3.8 ± 0.8 turns h-1, which is nearly two times higher than that of other seabirds. Egg turning rates increased with nest initiation date. We also examined egg turning rates and egg temperatures in relation to egg mercury contamination. Mercury contamination has been shown to be associated with reduced egg hatchability, and we hypothesized that mercury may decrease egg hatchability via altered egg turning behavior by parents. Despite the high variability in egg turning rates among individuals, the rate of egg turning was not related to mercury concentrations in sibling eggs. These findings highlight the need for further study concerning the potential determinants of egg turning behavior.

Egg turning behavior and incubation temperature in Forster’s terns in relation to mercury contamination

PubMed Central

Ackerman, Joshua T.; Shaffer, Scott A.

2018-01-01

Egg turning behavior is an important determinant of egg hatchability, but it remains relatively understudied. Here, we examined egg turning rates and egg temperatures in Forster’s terns (Sterna forsteri). We used artificial eggs containing a data logger with a 3-D accelerometer, a magnetometer, and a temperature thermistor to monitor parental incubation behavior of 131 tern nests. Overall, adults turned their eggs an average (±SD) of 3.8 ± 0.8 turns h-1, which is nearly two times higher than that of other seabirds. Egg turning rates increased with nest initiation date. We also examined egg turning rates and egg temperatures in relation to egg mercury contamination. Mercury contamination has been shown to be associated with reduced egg hatchability, and we hypothesized that mercury may decrease egg hatchability via altered egg turning behavior by parents. Despite the high variability in egg turning rates among individuals, the rate of egg turning was not related to mercury concentrations in sibling eggs. These findings highlight the need for further study concerning the potential determinants of egg turning behavior. PMID:29447185

Transcriptome Analysis of Thermal Parthenogenesis of the Domesticated Silkworm.

PubMed

Liu, Peigang; Wang, Yongqiang; Du, Xin; Yao, Lusong; Li, Fengbo; Meng, Zhiqi

2015-01-01

Thermal induction of parthenogenesis (also known as thermal parthenogenesis) in silkworms is an important technique that has been used in artificial insemination, expansion of hybridization, transgenesis and sericultural production; however, the exact mechanisms of this induction remain unclear. This study aimed to investigate the gene expression profile in silkworms undergoing thermal parthenogenesis using RNA-seq analysis. The transcriptome profiles indicated that in non-induced and induced eggs, the numbers of differentially expressed genes (DEGs) for the parthenogenetic line (PL) and amphigenetic line (AL) were 538 and 545, respectively, as determined by fold-change ≥ 2. Gene ontology (GO) analysis showed that DEGs between two lines were mainly involved in reproduction, formation of chorion, female gamete generation and cell development pathways. Upregulation of many chorion genes in AL suggests that the maturation rate of AL eggs was slower than PL eggs. Some DEGs related to reactive oxygen species removal, DNA repair and heat shock response were differentially expressed between the two lines, such as MPV-17, REV1 and HSP68. These results supported the view that a large fraction of genes are differentially expressed between PL and AL, which offers a new approach to identifying the molecular mechanism of silkworm thermal parthenogenesis.

Transcriptome Analysis of Thermal Parthenogenesis of the Domesticated Silkworm

PubMed Central

Du, Xin; Yao, Lusong; Li, Fengbo; Meng, Zhiqi

2015-01-01

Thermal induction of parthenogenesis (also known as thermal parthenogenesis) in silkworms is an important technique that has been used in artificial insemination, expansion of hybridization, transgenesis and sericultural production; however, the exact mechanisms of this induction remain unclear. This study aimed to investigate the gene expression profile in silkworms undergoing thermal parthenogenesis using RNA-seq analysis. The transcriptome profiles indicated that in non-induced and induced eggs, the numbers of differentially expressed genes (DEGs) for the parthenogenetic line (PL) and amphigenetic line (AL) were 538 and 545, respectively, as determined by fold-change ≥ 2. Gene ontology (GO) analysis showed that DEGs between two lines were mainly involved in reproduction, formation of chorion, female gamete generation and cell development pathways. Upregulation of many chorion genes in AL suggests that the maturation rate of AL eggs was slower than PL eggs. Some DEGs related to reactive oxygen species removal, DNA repair and heat shock response were differentially expressed between the two lines, such as MPV-17, REV1 and HSP68. These results supported the view that a large fraction of genes are differentially expressed between PL and AL, which offers a new approach to identifying the molecular mechanism of silkworm thermal parthenogenesis. PMID:26274803

Role of lipids for the reproductive success of the Arctic copepod Calanus glacialis

NASA Astrophysics Data System (ADS)

Hatlebakk, M. K.; Graeve, M.; Niehoff, B.; Johnsen, G.; Søreide, J.

2016-02-01

Extensive energy storage is common among polar animals, and a range of reproductive strategies have evolved from pure capital breeders, relying on stored energy only, to 100% income breeders where freshly ingested food fuel reproduction. The Arctic calanoid copepod Calanus glacialis is primarily a grazer that accumulates large lipid stores during spring and summer. The breeding strategy to this relatively large and lipid-rich copepod is somewhere on the continuum from pure capital to 100% income breeder. To investigate the importance of stored lipids versus freshly ingested food for the reproductive success of this key copepod we conducted a combined laboratory and field study on a high-Arctic population of C. glacialis in Svalbard from January to May. Total lipids, lipid composition, gonad maturation, egg production and egg hatching success were carefully followed for starved and algal fed females in the laboratory and for females in situ. Lipid stores decreased significantly over time even when food was available, both in laboratory and in field, suggesting that the females largely depended on stored resources for reproduction no matter of the food availability. Lipid reduction was most rapid during gonad maturation prior to first egg production. Almost all fed females spawned compared to only half of the starved ones, and number of eggs and the egg hatching success were significantly improved for fed females. When food was scarce, females produced fewer but more lipid-rich eggs as opposed to more eggs with less lipids when food was abundant - a strategy not previously described for C. glacialis. The fatty acid composition appeared to be more important than the total lipid content for ensuring high egg hatching success, and the polyunsaturated fatty acids 20:5(n-3) and 22:6(n-3), as well as the saturated fatty acids 16:0 and 18:0 seemed to be particularly important. We conclude that C. glacialis is capable of capital breeding, but primarily rely on fresh food for successful reproduction.

Effects of incubation temperature on growth and performance of the veiled chameleon (Chamaeleo calyptratus).

PubMed

Andrews, Robin M

2008-10-01

I evaluated the effect of incubation temperature on phenotypes of the veiled chameleon, Chamaeleo calyptratus. I chose this species for study because its large clutch size (30-40 eggs or more) allows replication within clutches both within and among experimental treatments. The major research objectives were (1) to assess the effect of constant low, moderate, and high temperatures on embryonic development, (2) to determine whether the best incubation temperature for embryonic development also produced the "best" hatchlings, and (3) to determine how a change in incubation temperature during mid-development would affect phenotype. To meet these objectives, I established five experimental temperature regimes and determined egg survival and incubation length and measured body size and shape, selected body temperatures, and locomotory performance of lizards at regular intervals from hatching to 90 d, or just before sexual maturity. Incubation temperature affected the length of incubation, egg survival, and body mass, but did not affect sprint speed or selected body temperature although selected body temperature affected growth in mass independently of treatment and clutch. Incubation at moderate temperatures provided the best conditions for both embryonic and post-hatching development. The highest incubation temperatures were disruptive to development; eggs had high mortality, developmental rate was low, and hatchlings grew slowly. Changes in temperature during incubation increased the among-clutch variance in incubation length relative to that of constant temperature treatments. Copyright 2008 Wiley-Liss, Inc.

Oviposition in Sweet Cherry by Reproductively Mature Western Cherry Fruit Fly (Tephritidae:Diptera) Fed Spinosad and Neonicotinoid Insecticide Baits

USDA-ARS?s Scientific Manuscript database

Western cherry fruit fly, Rhagoletis indifferens Curran, is a major pest of cherry, Prunus avium (L.) L., in the Pacific Northwest of the U.S. Spinosad bait is applied weekly to kill flies before they develop eggs, but its effects on oviposition by flies that are reproductively mature are unknown. ...

Reproductive biology of cuckoo ray Leucoraja naevus.

PubMed

Maia, C; Erzini, K; Serra-Pereira, B; Figueiredo, I

2012-09-01

The present study is the first to provide data on the reproductive biology of cuckoo ray Leucoraja naevus in Portuguese continental waters. No difference in size at maturity was detected between sexes, which was estimated as 56 cm total length. Spawning occurs all year round, but maximum activity was during winter months. Maximum fecundity is c. 63 eggs female(-1) year(-1). Encapsulated eggs are released in batches, nine in total with a mean number of seven extruded eggs in each batch. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Potential effects of global warming on the distribution of a temperate univoltine insect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rooney, T.P.; Hurd, L.E.

1993-06-01

Poleward migration to remain within temperature tolerance ranges as the earth warms poses a problem for species with limited dispersal abilities. The life cycle of a typical temperate univoltine insect, Tenodera sinensis (Mantodea: Mantidae), is constrained by degree-days per season: too few prevent maturation before killing frost in the fall; too many allow egg hatch prior to killing frost. We combined field observations of dispersal ability with laboratory measurements of the relationship between temperature and maturation rate, and applied these to a global warming model to predict the effect of climate change on regional distribution of this insect by 2100more » A.D. Based on the simplified biological assumptions of our model, T, sinensis would be reduced to local populations in the northern portions and higher elevations of its present broadly contiguous range, and species with similar life histories may face regional or total extinction.« less

Differential precocious sexual development of Proctoeces lintoni (Digenea: Fellodistomidae) in three sympatric species of keyhole limpets Fissurella spp. may affect transmission to the final host.

PubMed

Balboa, L; George-Nascimento, M; Ojeda, F P

2001-10-01

The prevalence, abundance, and developmental status of the digenetic trematode Proctoeces lintoni Siddiqui et Cable 1960 were compared in 3 species of keyhole limpets Fissurella. A total of 197 limpets was collected at Caleta Chome, south-central Chile. Fissurella picta and F. costata had the highest prevalence of infection, whereas F. picta showed the greatest abundance of parasites, which increased with host shell length. However, the frequency of P. lintoni specimens with eggs in the uterus was greatest in F. costata. These results suggest that an increased rate of development of a parasite in the intermediate host may shorten the residence time necessary for maturation in the final host. Thus, faster development of the parasite in F. costata suggests the possibility that the parasites transmitted through this host species have shorter maturation times in clingfishes than individuals transmitted via other limpet species.

Plasma steroid hormone profiles and reproductive biology of the epaulette shark, Hemiscyllium ocellatum.

PubMed

Heupel, M R; Whittier, J M; Bennett, M B

1999-10-01

Examination of the reproductive biology of the oviparous epaulette shark, Hemiscyllium ocellatum, was conducted on a wild population. Male sharks were found to reach maturity at between 55-60 cm total length (TL) and female sharks mature around 55 cm TL. Blood samples collected from mature male and female sharks were analyzed for sex steroid hormones to examine seasonal hormone patterns. Plasma samples were analyzed via radioimmunoassay techniques with female samples measured for estradiol, progesterone, and androgen concentrations, and male samples measured for androgen concentrations. Male androgen concentrations showed a single broad peak from July to October with maximum hormone concentrations (60 ng/ml) occurring in August. Male androgen concentrations were lowest in December-February (<20 ng/ml), and appeared to correlate with reproductive activity and water temperature. Female androgen concentrations were an order of magnitude lower than those for males and showed peaks in June (6 ng/ml) and December (8 ng/ml). Estradiol concentrations in females peaked during the months of September-November (0.5 ng/ml) coinciding with the egg laying period. Progesterone concentrations ranged up to 0.5 ng/ml prior to the mating season. Observations of ova size and egg production showed eggs develop in pairs and ova are ovulated at a size of 25-27 mm. Females lay eggs from August to January. Males were observed with swollen claspers from July through December, with the highest amount of sperm storage in the epididymis occurring between August through November. Our observations indicate that epaulette sharks in the waters near Heron Island mate from July through December. J. Exp. Zool. 284:586-594, 1999. Copyright 1999 Wiley-Liss, Inc.

The relationship of spectral sensitivity with growth and reproductive response in avian breeders (Gallus gallus)

PubMed Central

Yang, Ye-Feng; Jiang, Jing-Song; Pan, Jin-Ming; Ying, Yi-Bin; Wang, Xiao-Shuang; Zhang, Ming-Li; Lu, Min-Si; Chen, Xian-Hui

2016-01-01

A previous study demonstrated that birds that are exposed to light at night develop advanced reproductive systems. However, spectrum might also affect the photoperiodic response of birds. The present study was aimed to investigate the effects of spectral composition on the growth and reproductive physiology of female breeders, using pure light-emitting diode spectra. A total of 1,000 newly hatched female avian breeders (Gallus gallus) were equally allocated to white-, red-, yellow-, green- and blue-light treated groups. We found that blue-light treated birds had a greater and faster weight gain than did red- and yellow-light treated birds (P = 0.02 and 0.05). The red light expedited the sexual maturation of the chicks, whose age at sexual maturity was 7 and 14 days earlier than that of the green- and blue-light treated birds, respectively. The accumulative egg production of the red-light treated birds was 9 and 8 eggs more than that of the blue- and green-light treated birds. The peak lay rate of the red-light treated groups was significantly greater than the blue-light treated birds (P = 0.028). In conclusion, exposure to short-wavelength light appears to promote growth of female breeder birds, whereas exposure to long-wavelength light appears to accelerate reproductive performance. PMID:26765747

Sperm nuclear expansion and meiotic maturation in normal and gynogenetic eggs of the scallop, Chlamys farreri

NASA Astrophysics Data System (ADS)

Pan, Ying; Li, Qi; Yu, Ruihai; Wang, Rucai

2008-02-01

Sperm nuclear expansion, meiosis and the association of the male and female pronuclei leading to the four-cell stage in normal Chlamys farreri eggs were observed under a fluorescence microscope. The effects of ultraviolet (UV) irradiation on the fertilizing sperm were also examined. Both normal and UV-irradiated sperm nuclei enlarged at three distinct phases (phase A, metaphase I; phase B, polar body formation; and phase C, female pronuclear development and expansion) that were temporally correlated with meiotic process of the maternal chromosomes. Sperm nuclei underwent a rapid, initial enlargement during phase A, but condensed slightly during phase B, then re-enlarged during phase C. The effects of UV irradiation were not apparent during transformation of the sperm nucleus into a male pronucleus, and there was not any apparent effect on meiotic maturation and development of the female pronucleus. However, the rate of expansion of the UV-irradiated sperm nuclei and the size of male pronuclei were reduced apparently. Unlike the female pronucleus, the male pronucleus derived from sperm genome inactivated by UV irradiation did not form chromosomes, but became a dense chromatin body (DCB). At mitotic anaphase, DCB did not participate in the karyokinesis of the first cleavage as evidenced by chromosomal nondisjunction, demonstrating the effectiveness of using UV irradiation to induce gynogenetic scallop embryos.

Age-associated increase in aneuploidy and changes in gene expression in mouse eggs

PubMed Central

Pan, Hua; Ma, Pengpeng; Zhu, Wenting; Schultz, Richard M.

2008-01-01

An increase in the incidence of aneuploidy is well documented with increasing maternal age, in particular in human females. Remarkably, little is known regarding the underlying molecular basis for the age-associated increase in aneuploidy, which is a major source of decreased fertility in humans. Using mouse as a model system we find that eggs obtained from old mice (60–70 weeks of age) display a six-fold increase in the incidence of hyperploidy as assessed by chromosome spreads. Expression profiling of transcripts in oocytes and eggs obtained from young and old mice reveals that ~5% of the transcripts are differentially expressed in oocytes obtained from old females when compared to oocytes obtained from young females (6–12 weeks of age) and that this fraction increases to ~33% in eggs. The latter finding indicates that the normal pattern of degradation of maternal mRNAs that occurs during oocyte maturation is dramatically altered in eggs obtained from old mice and could therefore be a contributing source to the decline in fertility. Analysis of the differentially expressed transcripts also indicated that the strength of the spindle assembly checkpoint is weakened and that higher errors of microtubule-kinetochore interactions constitute part of molecular basis for the ageassociated increase in aneuploidy in females. Last, BRCA1 expression is reduced in oocytes obtained from old females and RNAi-mediated reduction of BRCA1 in oocytes obtained from young females results in perturbing spindle formation and chromosome congression following maturation. PMID:18342300

Effect of parental exposure to trenbolone and the brominated flame retardant BDE-47 on fertility in rainbow trout (Oncorhynchus mykiss)

PubMed Central

Schultz, Irv; Brown, Kim H.; Nagler, James J.

2008-01-01

We exposed sexually maturing male rainbow trout (Oncorhynchus mykiss) to BDE-47 (a polybrominated diphenyl ether) and female rainbow trout to trenbolone (an anabolic steroid). Male trout were orally exposed for 17 days to 55 μg/kg/day BDE-47 and female trout continuously exposed for 60–77 days to a measured trenbolone water concentration of 35 ng/L. After the exposure, eggs and semen were collected and in vitro fertilization trials performed using a sperm:egg ratio of 300,000:1. In the BDE-47 study, eggs from control females were fertilized with semen from exposed males, while in the trenbolone study, eggs from exposed females were fertilized with semen from control males. All treatments were evaluated at two–three early developmental time-points representing first cleavage (0.5 day), embryonic keel (9 days), and eyed stages (19 days), respectively. The results indicated that BDE-47 exposure did not alter fertility as embryonic survival was similar between control and exposed groups. Trenbolone exposure also did not alter embryo survival. However, in the embryos fertilized with eggs from trenbolone exposed females, a noticeable delay in developmental progress was observed. On day 19 when eye development is normally complete, the majority of the embryos either lacked eyes or displayed under-developed eyes, in contrast to control embryos. This finding suggests steroidal androgen exposure in sexually maturing female rainbow trout can impact developmental timing of F1 offspring. PMID:18397801

Effect of parental exposure to trenbolone and the brominated flame retardant BDE-47 on fertility in rainbow trout (Oncorhynchus mykiss).

PubMed

Schultz, Irv; Brown, Kim H; Nagler, James J

2008-07-01

We exposed sexually maturing male rainbow trout (Oncorhynchus mykiss) to BDE-47 (a polybrominated diphenyl ether) and female rainbow trout to trenbolone (an anabolic steroid). Male trout were orally exposed for 17 days to 55 microg/kg/day BDE-47 and female trout continuously exposed for 60-77 days to a measured trenbolone water concentration of 35 ng/L. After the exposure, eggs and semen were collected and in vitro fertilization trials performed using a sperm:egg ratio of 300,000:1. In the BDE-47 study, eggs from control females were fertilized with semen from exposed males, while in the trenbolone study, eggs from exposed females were fertilized with semen from control males. All treatments were evaluated at two-three early developmental time-points representing first cleavage (0.5 day), embryonic keel (9 days), and eyed stages (19 days), respectively. The results indicated that BDE-47 exposure did not alter fertility as embryonic survival was similar between control and exposed groups. Trenbolone exposure also did not alter embryo survival. However, in the embryos fertilized with eggs from trenbolone exposed females, a noticeable delay in developmental progress was observed. On day 19 when eye development is normally complete, the majority of the embryos either lacked eyes or displayed under-developed eyes, in contrast to control embryos. This finding suggests steroidal androgen exposure in sexually maturing female rainbow trout can impact developmental timing of F1 offspring.

In-vitro maturation of germinal vesicle and metaphase I eggs prior to cryopreservation optimizes reproductive potential in patients undergoing fertility preservation.

PubMed

Lee, Joseph A; Sekhon, Lucky; Grunfeld, Lawrence; Copperman, Alan B

2014-06-01

To evaluate current and previous findings related to a timely implementation of in-vitro maturation (IVM) of germinal vesicle, metaphase I and metaphase II oocytes with an optimal cryopreservation to determine whether IVM should be attempted prior to (fresh IVM) or IVM after cryopreservation (postthaw IVM). Mitochondrion, chromatin and spindle formation in both groups were interpreted from referenced studies to establish best management of all oocytes. The postthaw survival of germinal vesicle, metaphase I, fresh IVM-metaphase II and control metaphase II oocytes did not differ significantly [83.3% (n=9), 86.7% (n=12), 83% (n=57) and 86% (n=68), respectively]. Overall, combined survival and maturation were significantly higher (P<0.05) in the fresh IVM group at 63.8% (44 of 69) compared with the postthaw IVM group at 33.3% (nine of 27). Conservation of retrieved immature oocytes after vaginal oocyte retrieval has become a major concern for patients, as they strive to maximize the reproductive viability of all oocytes obtained during treatment. Oocyte cryopreservation is important for patients at risk of ovarian cancer, elective fertility preservation and potentially for ovum donation. The superior maturation rate of germinal vesicle and metaphase I oocytes in the fresh IVM vs. postthaw groups provides strong impetus to mature oocytes to the metaphase II stage prior to cryopreservation.

Spermatogenesis, the mature sperm, and sperm egg association in Nematospiroides dubius

NASA Technical Reports Server (NTRS)

Clark, W. H., Jr.

1974-01-01

Nematode spermatogenesis was investigated using the strongyloid Nematospiroides dubius. The primary spermatocytes, development of spermatids, and changes in the sperm in the female tract are described.

Coffee and its waste repel gravid Aedes albopictus females and inhibit the development of their embryos.

PubMed

Satho, Tomomitsu; Dieng, Hamady; Ahmad, Muhammad Hishamuddin Itam; Ellias, Salbiah Binti; Hassan, Ahmad Abu; Abang, Fatimah; Ghani, Idris Abd; Miake, Fumio; Ahmad, Hamdan; Fukumitsu, Yuki; Zuharah, Wan Fatma; Majid, Abdul Hafiz Ab; Kassim, Nur Faeza Abu; Hashim, Nur Aida; Ajibola, Olaide Olawunmi; Al-Khayyat, Fatima Abdulla; Nolasco-Hipolito, Cirilo

2015-05-14

Dengue is a prevalent arboviral disease and the development of insecticide resistance among its vectors impedes endeavors to control it. Coffee is drunk by millions of people daily worldwide, which is associated with the discarding of large amounts of waste. Coffee and its waste contain large amounts of chemicals many of which are highly toxic and none of which have a history of resistance in mosquitoes. Once in solution, coffee is brownish in colour, resembling leaf infusion, which is highly attractive to gravid mosquitoes. To anticipate the environmental issues related to the increasing popularity of coffee as a drink, and also to combat insecticide resistance, we explored the deterrence potentials of coffee leachates against the ovipositing and embryonic stages of the dengue vector, Aedes albopictus. In a series of choice, no-choice, and embryo toxicity bioassays, we examined changes in the ovipositional behaviours and larval eclosion of Ae. albopictus in response to coffee extracts at different concentrations. Oviposition responses were extremely low when ovicups holding highly concentrated extract (HCE) of coffee were the only oviposition sites. Gravid females retained increased numbers of mature eggs until 5 days post-blood feeding. When provided an opportunity to oviposit in cups containing coffee extracts and with water, egg deposition occurred at lower rates in those containing coffee, and HCE cups were far less attractive to females than those containing water only. Females that successfully developed in a coffee environment preferentially oviposited in such cups when in competition with preferred oviposition sites (water cups), but this trait did not continue into the fourth generation. Larval eclosion occurred at lower rates among eggs that matured in a coffee environment, especially among those that were maintained on HCE-moistened substrates. The observations of the present study indicate a pronounced vulnerability of Ae. albopictus to the presence of coffee in its habitats during the early phases of its life cycle. The observations that coffee repels gravid females and inhibits larval eclosion provide novel possibilities in the search for novel oviposition deterrents and anti-larval eclosion agents against dengue vectors.

Identification of Promising Mutants Associated with Egg Production Traits Revealed by Genome-Wide Association Study.

PubMed

Yuan, Jingwei; Sun, Congjiao; Dou, Taocun; Yi, Guoqiang; Qu, LuJiang; Qu, Liang; Wang, Kehua; Yang, Ning

2015-01-01

Egg number (EN), egg laying rate (LR) and age at first egg (AFE) are important production traits related to egg production in poultry industry. To better understand the knowledge of genetic architecture of dynamic EN during the whole laying cycle and provide the precise positions of associated variants for EN, LR and AFE, laying records from 21 to 72 weeks of age were collected individually for 1,534 F2 hens produced by reciprocal crosses between White Leghorn and Dongxiang Blue-shelled chicken, and their genotypes were assayed by chicken 600 K Affymetrix high density genotyping arrays. Subsequently, pedigree and SNP-based genetic parameters were estimated and a genome-wide association study (GWAS) was conducted on EN, LR and AFE. The heritability estimates were similar between pedigree and SNP-based estimates varying from 0.17 to 0.36. In the GWA analysis, we identified nine genome-wide significant loci associated with EN of the laying periods from 21 to 26 weeks, 27 to 36 weeks and 37 to 72 weeks. Analysis of GTF2A1 and CLSPN suggested that they influenced the function of ovary and uterus, and may be considered as relevant candidates. The identified SNP rs314448799 for accumulative EN from 21 to 40 weeks on chromosome 5 created phenotypic differences of 6.86 eggs between two homozygous genotypes, which could be potentially applied to the molecular breeding for EN selection. Moreover, our finding showed that LR was a moderate polygenic trait. The suggestive significant region on chromosome 16 for AFE suggested the relationship between sex maturity and immune in the current population. The present study comprehensively evaluates the role of genetic variants in the development of egg laying. The findings will be helpful to investigation of causative genes function and future marker-assisted selection and genomic selection in chickens.

Preliminary results of the Artemia salina experiments in biostack on LDEF

NASA Technical Reports Server (NTRS)

Graul, E. H.; Ruether, W.; Hiendl, C. O.

1992-01-01

The mosaic egg of the brine shrimp, Artemia salina, resting in blastula or gastrula state represents a system that during further development, proceeds without any further development to the larval stage, the free swimming nauplius. Therefore, injury to a single cell of the egg will be manifest in the larvae. In several experiments, it was shown that the passage of a single heavy ion through the shrimp egg damaged a cellular area large enough to disturb either embryogenesis or further development of the larvae, or the integrity of the adult individual. Emergence from the egg shell was heavily disturbed by the heavy ions as was hatching. Additional late effects, due to a hit by a heavy ion, are delayed of growth and of sexual maturity, and reduced fertility. Anomalies in the body and the extremities could be observed more frequently for the nauplii which had developed from eggs hit by heavy ions.

Costs of reproduction can explain the correlated evolution of semelparity and egg size: theory and a test with salmon.

PubMed

Kindsvater, Holly K; Braun, Douglas C; Otto, Sarah P; Reynolds, John D

2016-06-01

Species' life history traits, including maturation age, number of reproductive bouts, offspring size and number, reflect adaptations to diverse biotic and abiotic selection pressures. A striking example of divergent life histories is the evolution of either iteroparity (breeding multiple times) or semelparity (breed once and die). We analysed published data on salmonid fishes and found that semelparous species produce larger eggs, that egg size and number increase with salmonid body size among populations and species and that migratory behaviour and parity interact. We developed three hypotheses that might explain the patterns in our data and evaluated them in a stage-structured modelling framework accounting for different growth and survival scenarios. Our models predict the observation of small eggs in iteroparous species when egg size is costly to maternal survival or egg number is constrained. By exploring trait co-variation in salmonids, we generate new hypotheses for the evolution of trade-offs among life history traits. © 2016 John Wiley & Sons Ltd/CNRS.

Blood Feeding Status, Gonotrophic Cycle and Survivorship of Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) Caught in Churches from Merida, Yucatan, Mexico.

PubMed

Baak-Baak, C M; Ulloa-Garcia, A; Cigarroa-Toledo, N; Tzuc Dzul, J C; Machain-Williams, C; Torres-Chable, O M; Navarro, J C; Garcia-Rejon, J E

2017-12-01

Blood-feeding status, gonotrophic cycle, and survival rates of Aedes (Stegmyia) aegypti (L.) was investigated in catholic churches from Merida, Yucatan. Female Ae. aegypti were caught using backpack aspirator during 25 consecutive days in rainy (2015) and dry season (2016). Blood-feeding status was determined by external examination of the abdomen and classified as unfed, fed, and gravid. Daily changes in the parous-nulliparous ratio were recorded, and the gonotrophic cycle length was estimated by a time series analysis. Also, was observed the vitellogenesis to monitoring egg maturity. In total, 408 females Ae. aegypti were caught, and there was a significant difference in the number of females collected per season (Z = -6.729, P ≤ 0.05). A great number was caught in the rainy season (n = 329). In the dry season, 79 females were caught, which the fed females were twice greatest than the unfed. The length of gonotrophic cycle was estimated on the base of a high correlation coefficient value appearing every 4 days in rainy at 26.7 ± 1.22°C, and 3 days in dry season at 29.8 ± 1.47°C. The daily survival rate of the Ae. aegypti population was higher in both seasons, 0.94 and 0.93 for the rainy and dry season, respectively. The minimum time estimated for developing mature eggs after blood feeding was similar in both seasons (3.5 days in rainy versus 3.25 days in dry). The measurement of the vectorial capacity of Ae. aegypti in catholic churches could help to understand the dynamics of transmission of arboviruses in sites with high human aggregation.

Ejaculate and type of freezing extender affect rates of fertilization of horse oocytes in vitro.

PubMed

Roasa, L M; Choi, Y H; Love, C C; Romo, S; Varner, D D; Hinrichs, K

2007-09-01

In vitro fertilization (IVF) was performed on in vitro-matured equine oocytes in three experiments. Frozen-thawed sperm were prepared using swim-up separation and heparin treatment. In Experiment 1, fertilization was achieved with sperm from only one frozen ejaculate of four obtained from the same stallion. Within this ejaculate, fertilization rates were higher with fresh media, as compared to media held for 6-8 days before use (39.6% versus 7.3%, respectively; P<0.001). The type of bovine serum albumin used affected fertilization rates (4% versus 39.6%; P<0.001). To determine if IVF rates were influenced by factors associated with the freezing process (Experiment 2), a single ejaculate from a second stallion was frozen using eight variations in timing of steps in the freezing protocol. There were no differences among treatments in fertilization rates (range, 0-3%). In Experiment 3, fertilization rates of semen frozen in an extender containing 21.5% egg yolk were lower than fertilization rates of semen from the same ejaculate but frozen with a 3% egg-yolk extender (0% versus 15%, respectively; P<0.01). We inferred that rates of equine IVF with frozen-thawed sperm were influenced by ejaculate, the composition and age of the media used, and freezing extender. To our knowledge, this is the first report of ejaculate or extender differences affecting in vitro fertilization in this species. These factors may help to explain the great variability in fertilization rates reported with equine IVF, both among and within laboratories.

Nutrient Content of Brown Marmorated Stink Bug Eggs and Comparisons Between Experimental Uses

PubMed Central

Skillman, Victoria P

2017-01-01

Abstract Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), the brown marmorated stink bug (BMSB), has become a major pest. Seven experiments examined the nutrient content of their eggs in the context of female reproductive investment and use for experiments. Among 542 clusters examined, an average egg contained 23.50 ± 0.561 µg lipid, 3.17 ± 0.089 µg glycogen, and 3.08 ± 0.056 µg sugar. Mature eggs within a female’s ovary can make up 61% of her total lipid, 35% of glycogen, and 20% of sugar levels. Eggs obtained from a colony reared on a steady diet are expected to have consistent nutrient content. The age of a parental female only slightly affected the lipid level of oviposited eggs but did not affect glycogen or sugar levels. However, egg nutrient content can differ substantially by the source of the parental females; wild eggs had higher lipid but lower sugar content than colony-produced eggs. Further, the length of time that eggs are frozen influenced egg nutrient content. Freshly laid eggs had higher lipid and lower sugar levels than eggs frozen for 1 or 2 yr. Whether an egg turned grey following removal from cold storage did not affect nutrient content, nor did being frozen within 1 or 3 d of oviposition. The temperature at which eggs were left exposed did not impact egg nutrient content, but glycogen decreased and sugar increased with deployment time. This information combined with how factors affect host selection by natural enemies will help refine future experiments that use BMSB egg clusters.

Changes in the number of eggs loaded in Pantala flavescens females with age from mass flights (Odonata: Libellulidae).

PubMed

Ichikawa, Yuta; Watanabe, Mamoru

2014-11-01

The wandering glider dragonfly Pantala flavescens migrates to Japan every spring, where the population increases until autumn, in which mass flights often occur, followed by death in the winter. There have been no reports to date on the maturation process of this species throughout its lifespan in Japan. We collected females from mass flights when the flight height was low, and classified them into seven age stages by examining their wing condition. Very few females of the older stage were collected from the mass flights. The wing condition corresponded with the change in body color and with the egg production process in the ovaries. While pre-reproductive-stage females did not release eggs when treated with our artificial oviposition technique, each reproductive-stage female released about 640 eggs. Nearly all eggs released were fertilized. The ovaries developed with the stage, and reproductive-stage females had about 1100 ovarioles. The estimated maximum fecundity was about 29,000 eggs. The lifetime number of eggs laid of P. flavescens should be revealed by dissection.

Estimation of the rate of egg contamination from Salmonella-infected chickens.

PubMed

Arnold, M E; Martelli, F; McLaren, I; Davies, R H

2014-02-01

Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent causes for human gastroenteritis and is by far the predominant Salmonella serovar among human cases, followed by Salmonella Typhimurium. Contaminated eggs produced by infected laying hens are thought to be the main source of human infection with S. Enteritidis throughout the world. Although previous studies have looked at the proportion of infected eggs from infected flocks, there is still uncertainty over the rate at which infected birds produce contaminated eggs. The aim of this study was to estimate the rate at which infected birds produce contaminated egg shells and egg contents. Data were collected from two studies, consisting of 15 and 20 flocks, respectively. Faecal and environmental sampling and testing of ovaries/caeca from laying hens were carried out in parallel with (i) for the first study, testing 300 individual eggs, contents and shells together and (ii) for the second study, testing 4000 eggs in pools of six, with shells and contents tested separately. Bayesian methods were used to estimate the within-flock prevalence of infection from the faecal and hen post-mortem data, and this was related to the proportion of positive eggs. Results indicated a linear relationship between the rate of contamination of egg contents and the prevalence of infected chickens, but a nonlinear (quadratic) relationship between infection prevalence and the rate of egg shell contamination, with egg shell contamination occurring at a much higher rate than that of egg contents. There was also a significant difference in the rate of egg contamination between serovars, with S. Enteritidis causing a higher rate of contamination of egg contents and a lower rate of contamination of egg shells compared to non-S. Enteritidis serovars. These results will be useful for risk assessments of human exposure to Salmonella-contaminated eggs. © 2013 Crown copyright. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

Calcium at fertilization and in early development

PubMed Central

Whitaker, Michael

2012-01-01

Fertilization calcium waves are introduced and the evidence from which we can infer general mechanisms of these waves is presented. The two main classes of hypothesis put forward to explain the generation of the fertilization calcium wave are set out and it is concluded that initiation of the fertilization calcium wave can be most generally explained in inverterbrates by a mechanism in which an activating substance enters the egg from the sperm on sperm-egg fusion, activating the egg by stimulating phospholipase C activation through a src family kinase pathway and in mammals by the diffusion of a sperm-specific phospholipase C from sperm to egg on sperm-egg fusion. The fertilization calcium wave is then set into the context of cell cycle control and the mechanism of repetitive calcium spiking in mammalian eggs is investigated. Evidence that calcium signals control cell division in early embryos is reviewed, and it is concluded that calcium signals are essential at all three stages of cell division in early embryos. Evidence that phosphoinositide signalling pathways control the resumption of meiosis during oocyte maturation is considered. It is concluded on balance that the evidence points to a need for phosphoinositide/calcium signalling during resumption of meiosis. Changes to the calcium signalling machinery occur during meiosis to enable the production of a calcium wave in the mature oocyte when it is fertilized; evidence that the shape and structure of the endoplasmic reticulum alters dynamically during maturation and after fertilization is reviewed and the link between ER dynamics and the cytoskeleton is discussed. There is evidence that calcium signalling plays a key part in the development of patterning in early embryos. Morphogenesis in ascidian, frog and zebrafish embryos is briefly described to provide the developmental context in which calcium signals act. Intracellular calcium waves that may play a role in axis formation in ascidian are discussed. Evidence that the Wingless/calcium signalling pathway is a strong ventralizing signal in Xenopus, mediated by phoshoinositide signalling is adumbrated. The central role that calcium channels play in morphogenetic movements during gastrulation and in ectodermal and mesodermal gene expression during late gastrulation is demonstrated. Experiments in zebrafish provide a strong indication that calcium signals are essential for pattern formation and organogenesis. PMID:16371595

Female maturation, egg characteristics and fatty acids profile in the seahorse Hippocampus guttulatus.

PubMed

Planas, M; Quintas, P; Chamorro, A; Silva, C

2010-10-01

Knowledge of the biology and ecology of seahorses (Hippocampus spp.) is scarce, but has been increasing in recent years due to their conservation status. Captivity breeding programmes can be a valuable source of information on the reproductive biology of seahorses. A captive broodstock of Hippocampus guttulatus Cuvier 1829 was established in 2006 and kept under natural-like photoperiod and temperature. Female maturation was studied during the whole reproductive season in 2007. Most egg clutches were released from May (17°C; 15L:9D) to October (18°C; 13L:11D), with peak releases occurring in June-August (20°C; 16L:8D-14L:10D). Throughout the study, four egg morphotypes were found; two regression equations were proposed for estimating egg/yolk volume based on measurements of egg and yolk biometrics. Female weight was positively correlated with yolk volume/egg volume ratio (Y(v)/E(v)) (r(s)=0.523, n=21, P<0.05) but not with E(v) or Y(v). Egg dry weight (567±141μg) was correlated with Y(v) (r(s)=0.384, n=31, P<0.05). Mean clutch size and clutch biomass were 242±142 eggs and 137±87mg dry weight, respectively. Clutch size was positively correlated to female weight (r(s)=0.479, n=25, P<0.05). Inter-clutch intervals (days) were affected by temperature (°C) as described by the following equation: Interval=357.55e(-0.1283 Temp). Estimated inter-clutch intervals at 16, 18 and 20°C were 45.9, 35.5 and 27.5 days, respectively. Egg total lipids accounted for 31.9±3.1% dry weight. Absolute lipid content in eggs was correlated with egg dry weight (r(s)=0.907, n=41, P<0.001) and Y(v) (r(s)=0.384, n=41, P<0.5). In decreasing order of relative percentage, the most important fatty acids, were 18:1n9, 16:0, 18:2n6, 20:5n3, 18:0 and 22:6n-3. The level of n-3 HUFA was 18.5±0.7% (38.4±3.3mg/g dry weight). The profile of fatty acids in eggs resembled that displayed by the broodstock diet (enriched adult Artemia). Copyright © 2010 Elsevier B.V. All rights reserved.

Different routes lead to apoptosis in unfertilized sea urchin eggs.

PubMed

Philippe, Laetitia; Tosca, Lucie; Zhang, Wen Ling; Piquemal, Marion; Ciapa, Brigitte

2014-03-01

Results obtained in various species, from mammals to invertebrates, show that arrest in the cell cycle of mature oocytes is due to a high ERK activity. Apoptosis is stimulated in these oocytes if fertilization does not occur. Our previous data suggest that apoptosis of unfertilized sea urchin eggs is the consequence of an aberrant short attempt of development that occurs if ERK is inactivated. They contradict those obtained in starfish, another echinoderm, where inactivation of ERK delays apoptosis of aging mature oocytes that are nevertheless arrested at G1 of the cell cycle as in the sea urchin. This suggests that the cell death pathway that can be activated in unfertilized eggs is not the same in sea urchin and in starfish. In the present study, we find that protein synthesis is necessary for the survival of unfertilized sea urchin eggs, contrary to starfish. We also compare the effects induced by Emetine, an inhibitor of protein synthesis, with those triggered by Staurosporine, a non specific inhibitor of protein kinase that is widely used to induce apoptosis in many types of cells. Our results indicate that the unfertilized sea urchin egg contain different mechanisms capable of leading to apoptosis and that rely or not on changes in ERK activity, acidity of intracellular organelles or intracellular Ca and pH. We discuss the validity of some methods to investigate cell death such as measurements of caspase activation with the fluorescent caspase indicator FITC-VAD-fmk or acidification of intracellular organelles, methods that may lead to erroneous conclusions at least in the sea urchin model.

Artificial activation of mature unfertilized eggs in the malaria vector mosquito, Anopheles stephensi (Diptera, Culicidae).

PubMed

Yamamoto, Daisuke S; Hatakeyama, Masatsugu; Matsuoka, Hiroyuki

2013-08-01

In the past decade, many transgenic lines of mosquitoes have been generated and analyzed, whereas the maintenance of a large number of transgenic lines requires a great deal of effort and cost. In vitro fertilization by an injection of cryopreserved sperm into eggs has been proven to be effective for the maintenance of strains in mammals. The technique of artificial egg activation is a prerequisite for the establishment of in vitro fertilization by sperm injection. We demonstrated that artificial egg activation is feasible in the malaria vector mosquito, Anopheles stephensi (Diptera, Culicidae). Nearly 100% of eggs dissected from virgin females immersed in distilled water darkened, similar to normally oviposited fertilized eggs. It was revealed by the cytological examination of chromosomes that meiotic arrest was relieved in these eggs approximately 20 min after incubation in water. Biochemical examinations revealed that MAPK (mitogen-activated protein kinase)/ERK (extracellular signal-regulated protein kinase) and MEK (MAPK/ERK kinase) were dephosphorylated similar to that in fertilized eggs. These results indicate that dissected unfertilized eggs were activated in distilled water and started development. Injection of distilled water into body cavity of the virgin blood-fed females also induced activation of a portion of eggs in the ovaries. The technique of artificial egg activation is expected to contribute to the success of in vitro fertilization in A. stephensi.

Egg-laying behavior and morphological and chemical characterization of egg surface and egg attachment glue of the digger wasp Ampulex compressa (Hymenoptera, Ampulicidae).

PubMed

Gnatzy, Werner; Volknandt, Walter; Dzwoneck, Anja

2018-01-01

For providing their offspring females of the digger wasp species Ampulex compressa hunt cockroaches, paralyze them and attach as a rule one egg to the coxa of one of the mid legs of their prey. We observed the egg-laying behavior and examined with light- and scanning microscopy (i) nearly mature eggs from ovaries of freshly dissected females and (ii) eggs immediately after their deposition on the coxae of their prey. The length of the white bean-shaped eggs varied between 2.2 and 3.0 mm, their diameter between 0.66 and 0.72 mm, and their weight between 345 and 832 μg. The surface of fresh, untreated eggs shows even at higher magnifications (>20.000×) a smooth appearance. However, after conventional fixation, dehydration with ethyl-alcohol and critical-point drying the egg-surface exhibited a little bit texture. The eggs are at two-third of their underside glued to the coxa of the prey. With the naked eye the glue appears as a compact mass. The eggs may be mechanically removed from the substrate (their attachment site); however, in doing so the viscous attachment glue appears in a more fibrous consistence. The polypeptide composition washed off the egg surface and the glue revealed no similarities, whereas the molecular mass of two polypeptides were similar between glue and the Dufour's gland contents. Copyright © 2017. Published by Elsevier Ltd.

Growth and development of Gymnophalloides seoi in immunocompetent and immunosuppressed C3H/HeN mice

PubMed Central

Chung, Won-Jae; Kook, Jina; Seo, Min; Park, Yun-Kyu; Guk, Sang-Mee; Choi, Min-Ho; Lee, Soon-Hyung

1999-01-01

The growth and development of Gymnophalloides seoi were studied in C3H/HeN mice and effects of immunosuppression of the host on the worm development were observed. Two hundred metacercariae of G. seoi were orally administered to each mouse, and worms were recovered on days 1, 3, 5, 7, 14 and 21 post-infection (PI). The worm recovery rate was significantly higher in immunosuppressed (ImSP) mice than in immunocompetent (ImCT) mice except on days 1 and 3 PI. The worms attained sexual maturity by day 3 PI with eggs in the uterus, and worm dimensions and the number of uterine eggs continuously increased until day 14 PI in ImSP mice. Worms recovered from ImSP mice were significantly larger in size than those from ImCT mice on days 1 and 3 PI, and the number of uterine eggs was significantly larger in ImSP mice on days 5 and 7 PI. Genital organs such as the ovary, testes, and vitellaria, that were already developed in the metacercarial stage, grew a little in size until day 14 PI. The results show that the C3H/HeN mouse is, though not excellent, a suitable laboratory host for G. seoi. PMID:10188379

Characterization of Tolypocladium cylindrosporum (Hypocreales: Ophiocordycipitaceae) and Its Impact Against Aedes aegypti and Aedes albopictus Eggs at Low Temperature.

PubMed

Flor-Weiler, Lina B; Rooney, Alejandro P; Behle, Robert W; Muturi, Ephantus J

2017-09-01

We examined the growth characteristics of Tolypocladium cylindrosporum IBT 41712 and its potential to infect eggs of Aedes aegypti and Ae. albopictus at a low temperature (15°C). When grown on Sabouraud dextrose agar supplemented with yeast extract, the IBT 41712 formed white colonies turning to a slightly darker, off-white color when mature. The mycelia bore swollen conidiophores producing smooth-walled, oblong to cylindrical conidia with varying sizes, ranging from 1.5 to 3.5 μm long. To determine the optimum temperature for the fungus, we cultured the fungus at eight temperatures (4°C, 12°C, 15°C, 21°C, 28°C, 33°C, 37°C, and 40°C) and measured the diametric growth. The optimum temperature for growth was 28°C since it had the highest diametric growth rate (2.1 ± 0.05 mm/day) and the fastest sporulation period (within 8-10 days of incubation). There was no fungal growth at the 3 highest temperatures (33°C, 37°C, and 40°C) but plates incubated at 33°C, when shifted to optimal temperature (28°C), showed visible growth indicating that following incubation at 33°C, the fungus remained viable. The IBT 41712 successfully infected mosquito eggs at 15°C. Fungal treatment induced egg hatch on moist seed-germination paper and this effect was more pronounced in Ae. aegypti compared to Ae. albopictus. When treated eggs were immersed in dH 2 O 21 days posttreatment, larval hatch of both Ae. aegypti (control = 91%, 1 × 10 7 conidia/ml, fungal treatment = 0%) and Ae. albopictus (control = 85%, fungal treatment = 28%) was significantly lower in fungal treatment compared to the controls. The ability of the strain to grow in a wide temperature range, and effectively infect mosquito eggs and induce egg hatch at a low temperature warrants further investigation for its potential as a mosquito control agent targeting eggs that overwinter or undergo long diapause.

Frequent baked egg ingestion was not associated with change in rate of decline in egg skin prick test in children with challenge confirmed egg allergy.

PubMed

Tey, D; Dharmage, S C; Robinson, M N; Allen, K J; Gurrin, L C; Tang, M L K

2012-12-01

It is controversial whether egg-allergic children should strictly avoid all forms of egg, or if regular ingestion of baked egg will either delay or hasten the resolution of egg allergy. This is the first study to examine the relationship between frequency of baked egg ingestion and rate of decline in egg skin prick test size in egg-allergic children. This was a retrospective clinical cohort study. All children with challenge-proven egg allergy who attended the Royal Children's Hospital Allergy Department 1996-2005 and had at least two egg skin prick tests performed in this period were included (n = 125). Frequency of baked egg ingestion was assessed by telephone questionnaire as follows: (a) frequent (> once per week), (b) regular (> once every 3 months, up to ≤ once per week) or (c) strict avoidance (≤ once every 3 months). The relationship between frequency of baked egg ingestion and rate of decline in egg skin prick test size was examined by multiple linear regression, adjusting for potential confounders. Mean rate of decline in egg skin prick test size in all children was 0.7 mm/year (95% CI 0.5-1.0 mm/year). There was no evidence (P = 0.57) that the rate of decline in egg skin prick test size differed between children who undertook frequent ingestion (n = 21, mean 0.4 mm/year, 95% CI -0.3-1.2 mm/year), regular ingestion (n = 37, mean 0.9 mm/year, 95% CI 0.4-1.4 mm/year) or strict avoidance (n = 67, mean 0.7 mm/year, 95% CI 0.4-1.1 mm/year) of baked egg. Compared with strict dietary avoidance, frequent consumption of baked egg was not associated with a different rate of decline in egg skin prick test size in egg-allergic children. Given that dietary restrictions can adversely impact on the family, it is reasonable to consider liberalizing baked egg in the diet of egg-allergic children. © 2012 Blackwell Publishing Ltd.

Optimal egg size in a suboptimal environment: reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) in central Arizona, USA

USGS Publications Warehouse

Lovich, Jeffrey E.; Madrak, Sheila V.; Drost, Charles A.; Monatesti, Anthony J.; Casper, Dennis; Znari, Mohammed

2012-01-01

We studied the reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) at Montezuma Well, a chemically-challenging natural wetland in central Arizona, USA. Females matured between 115.5 and 125 mm carapace length (CL) and 36-54% produced eggs each year. Eggs were detected in X-radiographs from 23 April-28 September (2007-2008) and the highest proportion (56%) of adult females with eggs occurred in June and July. Clutch frequency was rarely more than once per year. Clutch size was weakly correlated with body size, ranged from 1-8 (mean = 4.96) and did not differ significantly between years. X-ray egg width ranged from 17.8-21.7 mm (mean 19.4 mm) and varied more among clutches than within. Mean X-ray egg width of a clutch did not vary significantly with CL of females, although X-ray pelvic aperture width increased with CL. We observed no evidence of a morphological constraint on egg width. In addition, greater variation in clutch size, relative to egg width, suggests that egg size is optimized in this hydrologically stable but chemically-challenging habitat. We suggest that the diversity of architectures exhibited by the turtle pelvis, and their associated lack of correspondence to taxonomic or behavioral groupings, explains some of the variation observed in egg size of turtles.

Tapeworm eggs in a 270 million-year-old shark coprolite.

PubMed

Dentzien-Dias, Paula C; Poinar, George; de Figueiredo, Ana Emilia Q; Pacheco, Ana Carolina L; Horn, Bruno L D; Schultz, Cesar L

2013-01-01

Remains of parasites in vertebrates are rare from the Mesozoic and Paleozoic. Once most parasites that live in - or pass through - the gastrointestinal tract of vertebrates, fossil feces (coprolites) or even intestinal contents (enterolites) can eventually preserve their remains. Here we announce the discovery of a spiral shark coprolite from the Paleozoic bearing a cluster of 93 small oval-elliptical smooth-shelled structures, interpreted as eggs of a tapeworm.The eggs were found in a thin section of an elasmobranch coprolite. Most of the eggs are filled by pyrite and some have a special polar swelling (operculum), suggesting they are non-erupted eggs. One of the eggs contains a probable developing larva. The eggs are approximately 145-155 µm in length and 88-100 µm in width and vary little in size within the cluster. The depositional and morphological features of the eggs closely resemble those of cestodes. Not only do the individual eggs have features of extant tapeworms, but their deposition all together in an elongate segment is typical to modern tapeworm eggs deposited in mature segments (proglottids). This is the earliest fossil record of tapeworm parasitism of vertebrates and establishes a timeline for the evolution of cestodes. This discovery shows that the fossil record of vertebrate intestinal parasites is much older than was hitherto known and that the interaction between tapeworms and vertebrates occurred at least since the Middle-Late Permian.

Reproductive characteristics and population decline of four species of skate (Rajidae) off the eastern coast of Canada.

PubMed

Mcphie, R P; Campana, S E

2009-07-01

Four of the most common species of skate (Rajidae) were studied off eastern Canada to determine if their reproductive characteristics were linked to their population trajectories. The fecundity of the winter skate Leucoraja ocellata, the little skate Leucoraja erinacea, the thorny skate Amblyraja radiata and the smooth skate Malacoraja senta averaged between 41 and 56 egg cases per year for each species. For all species but L. ocellata, males matured at larger sizes and at later ages than females. Theoretical rates of population increase for non-equilibrium populations of L. ocellata (c. 0.07), M. senta (c. 0.14) and L. erinacea and A. radiata (c. 0.20) were low compared to most fishes, indicating that north-west Atlantic skates are intrinsically unproductive, yet are theoretically capable of supporting low-level fisheries. Nevertheless, the results of 36 years of research surveys indicate that the abundance of mature L. ocellata, A. radiata and M. senta all decreased by >90% since 1970, indicating that past fishing mortality (both directed and undirected) has outstripped the net productivity of the skate populations on the eastern Scotian Shelf. The relationship between maximum age (t(max)) and age of maturity (t(mat)) was a better predictor of population growth rate than was body size, with the species exhibiting the highest ratios of t(mat) :t(max) (L. ocellata = 0.68, M. senta = 0.66) having the lowest predicted population growth rates. L. ocellata appears to have the lowest productivity and has experienced the greatest population decline, thus raising concerns over its future status.

How dietary plant nectar affects the survival, growth, and fecundity of a cursorial spider Cheiracanthium inclusum (Araneae: Miturgidae).

PubMed

Taylor, R M; Pfannenstiel, R S

2009-10-01

We measured the effects of plant nectar consumption on Cheiracanthium inclusum (Hentz) (Miturgidae), an agriculturally important spider. Newly emerged spiderlings were reared on the eggs of Helicoverpa zea (Boddie) at four prey densities, 1, 5, 25, or 125 eggs, three times a week, with or without nectar. Nectar came from the extrafloral nectaries of Indian almond, Terminalia cattapa L. (Combretaceae). The addition of nectar to prey (1) allowed spiderlings on the 1-egg diet to survive longer and molt many more times; (2) allowed virtually all of the spiderlings on the 5-egg diet to become small adults and 50% to mate and reproduce versus those without nectar, none of which matured to adulthood; and (3) increased fecundity of females on 5-egg and 25-egg diets to the level of females fed five times the amount of prey. These results show that spiders that feed on nectar increase their fitness with increased survival, growth, and fecundity, particularly when density of prey is inadequate or marginal.

75 FR 55292 - Amendment to Egg Research and Promotion Order and Regulations To Increase the Rate of Assessment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-10

...] Amendment to Egg Research and Promotion Order and Regulations To Increase the Rate of Assessment and.... SUMMARY: This proposed rule would amend the Egg Research and Promotion Order (Order) to increase the assessment rate on egg producers paying assessments to the American Egg Board (AEB) from 10 cents to 15 cents...

Juvenile exposure to predator cues induces a larger egg size in fish

PubMed Central

Segers, Francisca H. I. D.; Taborsky, Barbara

2012-01-01

When females anticipate a hazardous environment for their offspring, they can increase offspring survival by producing larger young. Early environmental experience determines egg size in different animal taxa. We predicted that a higher perceived predation risk by juveniles would cause an increase in the sizes of eggs that they produce as adults. To test this, we exposed juveniles of the mouthbrooding cichlid Eretmodus cyanostictus in a split-brood experiment either to cues of a natural predator or to a control situation. After maturation, females that had been confronted with predators produced heavier eggs, whereas clutch size itself was not affected by the treatment. This effect cannot be explained by a differential female body size because the predator treatment did not influence growth trajectories. The observed increase of egg mass is likely to be adaptive, as heavier eggs gave rise to larger young and in fish, juvenile predation risk drops sharply with increasing body size. This study provides the first evidence that predator cues perceived by females early in life positively affect egg mass, suggesting that these cues allow her to predict the predation risk for her offspring. PMID:21976689

Homochiral Asymmetric Triacylglycerol Isomers in Egg Yolk.

PubMed

Nagai, Toshiharu; Ishikawa, Keiko; Yoshinaga, Kazuaki; Yoshida, Akihiko; Beppu, Fumiaki; Gotoh, Naohiro

2017-12-01

The composition of triacylglycerol (TAG) positional isomer (-PI) and enantiomer (-E) in immature chicken egg yolk, mature chicken yolk, and chicken meat was examined. POO (consisting of one palmitic acid (P) and two oleic acids (Os)), PPO (consisting of two Ps and one O), and PPL (consisting of two Ps and one linoleic acid (L)) were treated as representative TAG molecular species in all the analytical samples because P, O, and L were the major fatty acids comprising egg and chicken meat. sn-POO (binding P at sn-1 position) was predominant in egg yolks, while sn-OOP and sn-OPO were present in chicken meat. This difference was ascribed to the different roles of these isomers as nutrients, because TAG in egg yolk is important for new born organisms and TAG in chicken meat is used for fat accumulation. The compositions of the TAG isomers in PPO and PPL in egg yolk were similar, and O and L did not bind at the sn-1 position. In contrast, all the isomers of PPO and PPL were found in chicken meat. These results imply that the TAG structure could be modified so that the nutrient requirement is fulfilled in egg yolk and chicken meat.

Growth and fatbody cycles in feral populations of the African clawed frog, Xenopus laevis (Pipidae), in California with comments on reproduction

USGS Publications Warehouse

McCoid, M.J.; Fritts, T.H.

1989-01-01

Feral populations of the African clawed frog (Xenopus laevis) exist in several areas of southern California. By following the first cohort of progeny produced by African clawed frogs at a recently colonized site, data on the growth rates and age at first maturity were obtained in field conditions. Females reached maturity at an earlier age than males, grew faster than males, and attained body lengths up to 25% larger than males. Larger females were capable of producing larger numbers of eggs than small females and, therefore, had greater reproductive potential. The relatively stable ambient temperatures of southern California contributed to the possibility of reproduction of clawed frogs during all but the coolest periods of the year. Cycles detected in the mass of fatbodies suggested that nutrients were mobilized from fat prior to and during ovulation. The amount of fat in females varied widely, but fat in males tended to accumulate as the males grew during the study period.

Growth and fat-body cycles in feral populations of the African clawed frog, Xenopus laevis (Pipidae), in California with comments on reproduction

USGS Publications Warehouse

McCoid, Michael J.; Fritts, Thomas H.

1989-01-01

Feral populations of the African clawed frog (Xenopus laevis) exist in several areas of southern California. By following the first cohort of progeny produced by African clawed frogs at a recently colonized site, data on the growth rates and age at first maturity were obtained in field conditions. Females reached maturity at an earlier age than males, grew faster than males, and attained body lengths up to 25% larger than males. Larger females were capable of producing larger numbers of eggs than small females and, therefore, had greater reproductive potential. The relatively stable ambient temperatures of southern California contributed to the possibility of reproduction of clawed frogs during all but the coolest periods of the year. Cycles detected in the mass of fatbodies suggested that nutrients were mobilized from fat prior to and during ovulation. The amount of fat in females varies widely, but fat in males tended to accumulate as the males grew during the study period.

Host selection and gonotrophic cycle length of Anopheles punctimacula in southern Mexico.

PubMed

Ulloa, Armando; Gonzalez-Cerón, Lilia; Rodríguez, Mario H

2006-12-01

The host preference, survival rates, and length of the gonotrophic cycle of Anopheles punctimacula was investigated in southern México. Mosquitoes were collected in 15-day separate experiments during the rainy and dry seasons. Daily changes in the parous-nulliparous ratio were recorded and the gonotrophic cycle length was estimated by a time series analysis. Anopheles punctimacula was most abundant during the dry season and preferred animals to humans. The daily survival rate in mosquitoes collected in animal traps was 0.96 (parity rate = 0.86; gonotrophic cycle = 4 days). The length of gonotrophic cycle of 4 days was estimated on the base of a high correlation coefficient value appearing every 4 days. The minimum time estimated for developing mature eggs after blood feeding was 72 h. The proportion of mosquitoes living enough to transmit Plasmodium vivax malaria during the dry season was 0.35.

Parthenogenesis and somatic cell nuclear transfer in sheep oocytes using Polscope.

PubMed

Nandedkar, Pandit; Chohan, Parul; Patwardhan, Archana; Gaikwad, Santosh; Bhartiya, Deepa

2009-07-01

Parthenogenesis and Somatic cell nuclear transfer (SCNT) techniques, offer a unique approach to manipulate the genetic composition of derived human embryonic stem cells - an essential step if the full opportunities for disease modeling, drug discovery or individualized stem cell therapy are to be realized. The present study describes the use of sheep oocytes to acquire expertise and establish methods to reconstruct embryos for obtaining blastocysts before venturing into human SCNT where the oocytes are a very precious starting material. Maturation of sheep eggs in vitro for 20-24 hr resulted in 65% metaphase II (MII) eggs which were either parthenogenetically activated using calcium ionomycin or ethanol or subjected to SCNT using cumulus cell as somatic cell. Sixteen blastocysts were produced by parthenogenetic activation of 350 eggs whereas reconstructed embryos, after SCNT carried out in 139 eggs, progressed only up to morula stage. The procedure of parthenogenesis and SCNT will be useful to generate autologous ES cells using human eggs.

Reproductive traits of tropical deep-water pandalid shrimps ( Heterocarpus ensifer) from the SW Gulf of Mexico

NASA Astrophysics Data System (ADS)

Briones-Fourzán, Patricia; Barradas-Ortíz, Cecilia; Negrete-Soto, Fernando; Lozano-Álvarez, Enrique

2010-08-01

Heterocarpus ensifer is a tropical deep-water pandalid shrimp whose reproductive features are poorly known. We examined reproductive traits of a population of H. ensifer inhabiting the continental slope (311-715 m in depth) off the Yucatan Peninsula, Mexico (SW Gulf of Mexico). Size range of the total sample ( n=816) was 10.4-38.9 mm carapace length. Females grow larger than males, but both sexes mature at 57% of their maximum theoretical size and at ˜30% of their total lifespan. Among adult females, the proportion of ovigerous females was high in all seasons, indicating year-round reproduction. Most females carrying embryos in advanced stages of development had ovaries in advanced stages of maturation, indicating production of successive spawns. In the autumn, however, the proportion of ovigerous females and the condition index of these females were lower compared to other seasons. This pattern potentially reflects a reduction in food resources following the summer minimum in particulate organic carbon flux to the deep benthos, as reported in previous studies. Spawns consisting of large numbers (16024±5644, mean±SD) of small eggs (0.045±0.009 mm 3) are consistent with extended planktotrophic larval development, an uncommon feature in deep-water carideans. Egg number increased as a power function of female size but with substantial variability, and egg size varied widely within and between females. There was no apparent trade-off between egg number and egg size and neither of these two variables was influenced by female condition. These results indicate iteroparity and a high and variable reproductive effort, reflecting a reproductive strategy developed to compensate for high larval mortality. The present study provides a baseline to compare reproductive traits between Atlantic populations of this tropical deep-water pandalid.

In Vitro Cultivation of Cymatocarpus solearis (Brachycoeliidae) Metacercariae to Obtain the Adult Stage without the Marine Turtle Definitive Host

PubMed Central

Álvarez-Cadena, José

2010-01-01

In vitro cultivation of trematodes would assist studies on the basic biology of the parasites and their hosts. This is the first study to use the yolk of unfertilized chicken eggs as a simple and successful method of ovocultivation and the first time to obtain the adult-stage of the trematode Cymatocarpus solearis Braun, 1899 (Digenea: Brachycoeliidae). Chicken eggs were inoculated with metacercariae from the muscle of the spiny lobster, Panulirus argus (Latreille, 1804). The metacercariae were excysted and incubated for 576 hr (24 days) at 38℃ to obtain the adult stage. Eggs in utero were normal in shape and light brown color. The metacercariae developed into mature parasites that have been identified as the adult-stage found in marine turtles. The adult lobsters collected in Quintana Roo State, Mexico, showed the prevalence of 49.4% and the mean intensity of 26.0 per host (n = 87). A statistical study was performed to determine that no parasitic preference was detected for male versus female parasitized lobsters. Morphometric measurements of the adult-stage of C. solearis obtained in our study have been deposited in the National Helminths Collection of the Institute of Biology of the National Autonomous University of Mexico. This study is significant because it is the first time that a digenean of the family Brachycoeliidae has been demonstrated to develop in vitro from metacercariae into adults capable of producing eggs using the yolk of unfertilized chicken eggs. Secondly, this technique allows to obtain the adult stage of C. solearis without the presence of its marine turtle host, allows us to describe the mature parasites, and thus contribute to our understanding of the biology of C. solearis. PMID:20333285

Oocyte membrane localization of vitellogenin receptor coincides with queen flying age, and receptor silencing by RNAi disrupts egg formation in fire ant virgin queens.

PubMed

Lu, Hsiao-Ling; Vinson, S B; Pietrantonio, Patricia V

2009-06-01

In ant species in which mating flights are a strategic life-history trait for dispersal and reproduction, maturation of virgin queens occurs. However, the specific molecular mechanisms that mark this transition and the effectors that control premating ovarian growth are unknown. The vitellogenin receptor (VgR) is responsible for vitellogenin uptake during egg formation in insects. In the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), virgin queens have more abundant VgR transcripts than newly mated queens, but limited egg formation. To elucidate whether the transition to egg production involved changes in VgR expression, we investigated both virgin and mated queens. In both queens, western blot analysis showed an ovary-specific VgR band (approximately 202 kDa), and immunofluorescence analysis of ovaries detected differential VgR localization in early- and late-stage oocytes. However, the VgR signal was much lower in virgin queens ready to fly than in mated queens 8 h post mating flight. In virgin queens, the receptor signal was first observed at the oocyte membrane beginning at day 12 post emergence, coinciding with the 2 weeks of maturation required before a mating flight. Thus, the membrane localization of VgR appears to be a potential marker for queen mating readiness. Silencing of the receptor in virgin queens through RNA interference abolished egg formation, demonstrating that VgR is involved in fire ant ovary development pre mating. To our knowledge, this is the first report of RNA interference in any ant species and the first report of silencing of a hymenopteran VgR.

In vitro cultivation of Cymatocarpus solearis (Brachycoeliidae) metacercariae to obtain the adult stage without the marine turtle definitive host.

PubMed

Grano-Maldonado, Mayra; Alvarez-Cadena, José

2010-03-01

In vitro cultivation of trematodes would assist studies on the basic biology of the parasites and their hosts. This is the first study to use the yolk of unfertilized chicken eggs as a simple and successful method of ovocultivation and the first time to obtain the adult-stage of the trematode Cymatocarpus solearis Braun, 1899 (Digenea: Brachycoeliidae). Chicken eggs were inoculated with metacercariae from the muscle of the spiny lobster, Panulirus argus (Latreille, 1804). The metacercariae were excysted and incubated for 576 hr (24 days) at 38 to obtain the adult stage. Eggs in utero were normal in shape and light brown color. The metacercariae developed into mature parasites that have been identified as the adult-stage found in marine turtles. The adult lobsters collected in Quintana Roo State, Mexico, showed the prevalence of 49.4% and the mean intensity of 26.0 per host (n = 87). A statistical study was performed to determine that no parasitic preference was detected for male versus female parasitized lobsters. Morphometric measurements of the adult-stage of C. solearis obtained in our study have been deposited in the National Helminths Collection of the Institute of Biology of the National Autonomous University of Mexico. This study is significant because it is the first time that a digenean of the family Brachycoeliidae has been demonstrated to develop in vitro from metacercariae into adults capable of producing eggs using the yolk of unfertilized chicken eggs. Secondly, this technique allows to obtain the adult stage of C. solearis without the presence of its marine turtle host, allows us to describe the mature parasites, and thus contribute to our understanding of the biology of C. solearis.

Broodstock management and hormonal manipulations of fish reproduction.

PubMed

Mylonas, Constantinos C; Fostier, Alexis; Zanuy, Silvia

2010-02-01

Control of reproductive function in captivity is essential for the sustainability of commercial aquaculture production, and in many fishes it can be achieved by manipulating photoperiod, water temperature or spawning substrate. The fish reproductive cycle is separated in the growth (gametogenesis) and maturation phase (oocyte maturation and spermiation), both controlled by the reproductive hormones of the brain, pituitary and gonad. Although the growth phase of reproductive development is concluded in captivity in most fishes-the major exemption being the freshwater eel (Anguilla spp.), oocyte maturation (OM) and ovulation in females, and spermiation in males may require exogenous hormonal therapies. In some fishes, these hormonal manipulations are used only as a management tool to enhance the efficiency of egg production and facilitate hatchery operations, but in others exogenous hormones are the only way to produce fertilized eggs reliably. Hormonal manipulations of reproductive function in cultured fishes have focused on the use of either exogenous luteinizing hormone (LH) preparations that act directly at the level of the gonad, or synthetic agonists of gonadotropin-releasing hormone (GnRHa) that act at the level of the pituitary to induce release of the endogenous LH stores, which, in turn act at the level of the gonad to induce steroidogenesis and the process of OM and spermiation. After hormonal induction of maturation, broodstock should spawn spontaneously in their rearing enclosures, however, the natural breeding behavior followed by spontaneous spawning may be lost in aquaculture conditions. Therefore, for many species it is also necessary to employ artificial gamete collection and fertilization. Finally, a common question in regards to hormonal therapies is their effect on gamete quality, compared to naturally maturing or spawning broodfish. The main factors that may have significant consequences on gamete quality-mainly on eggs-and should be considered when choosing a spawning induction procedure include (a) the developmental stage of the gonads at the time the hormonal therapy is applied, (b) the type of hormonal therapy, (c) the possible stress induced by the manipulation necessary for the hormone administration and (d) in the case of artificial insemination, the latency period between hormonal stimulation and stripping for in vitro fertilization. Copyright 2009 Elsevier Inc. All rights reserved.

Adaptation of the Egg of the Desert Beetle, Microdera punctipennis (Coleoptera: Tenebrionidae), to Arid Environment

PubMed Central

Wang, Yan; Shi, Meng; Hou, Xiaojuan; Meng, Shanshan; Zhang, Fuchun; Ma, Ji

2014-01-01

Abstract Microdera punctipennis Kaszab (Coleoptera: Tenebrionidae) is an endemic species in Guerbantonggut desert in China. To explore the ways that M. punctipennis egg adapts to dry desert environment, morphological characteristics of the egg was investigated along with the egg of the nondesert beetle Tenebrio molitor (Coleoptera: Tenebrionidae). Water loss rate and survival rate of these eggs under different dry treatments (relative humidity0, 10, and 20%) were measured to evaluate the desiccation resistance of the eggs at different developmental stages (day 0, 2, and 5 eggs). Our results showed that the 50-egg weight in T. molitor was heavier than M. punctipennis , while the 50-first-instar larva weight in T. molitor was almost the same as in M. punctipennis . The water loss rate of M. punctipennis egg under dry conditions was significantly lower than T. molitor , and the egg survival rate was significantly higher than T. molitor . The estimated developmental threshold temperature of M. punctipennis egg was 18.30°C, and the critical thermal maximum of M. punctipennis egg is above 39°C. These features partly account for the adaptability of M. punctipennis to desert environment in egg stage. PMID:25525108

Calcium and Egg Activation in Drosophila

PubMed Central

Sartain, Caroline V.; Wolfner, Mariana F.

2012-01-01

Summary In many animals, a rise in intracellular calcium levels is the trigger for egg activation, the process by which an arrested mature oocyte transitions to prepare for embryogenesis. In nearly all animals studied to date, this calcium rise, and thus egg activation, is triggered by the fertilizing sperm. However in the insects that have been examined, fertilization is not necessary to activate their oocytes. Rather, these insects’ eggs activate as they transit through the female’s reproductive tract, regardless of male contribution. Recent studies in Drosophila have shown that egg activation nevertheless requires calcium and that the downstream events and molecules of egg activation are also conserved, despite the difference in initial trigger. Genetic studies have uncovered essential roles for the calcium-dependent enzyme calcineurin and its regulator calcipressin, and have hinted at roles for calmodulin, in Drosophila egg activation. Physiological and in vitro studies have led to a model in which mechanical forces that impact the Drosophila oocyte as it moves through the reproductive tract triggers the influx of calcium from the external environment, thereby initiating egg activation. Future research will aim to test this model, as well as to determine the spatiotemporal dynamics of cytoplasmic calcium flux and mode of signal propagation in this unique system. PMID:23218670

Translational control by cytoplasmic polyadenylation during Xenopus oocyte maturation: characterization of cis and trans elements and regulation by cyclin/MPF.

PubMed

McGrew, L L; Richter, J D

1990-11-01

The expression of certain maternal mRNAs during oocyte maturation is regulated by cytoplasmic polyadenylation. To understand this process, we have focused on a maternal mRNA from Xenopus termed G10. This mRNA is stored in the cytoplasm of stage 6 oocytes until maturation when the process of poly(A) elongation stimulates its translation. Deletion analysis of the 3' untranslated region of G10 RNA has revealed that two sequence elements, UUUUUUAU and AAUAAA were both necessary and sufficient for polyadenylation and polysomal recruitment. In this communication, we have defined the U-rich region that is optimal for polyadenylation as UUUUUUAUAAAG, henceforth referred to as the cytoplasmic polyadenylation element (CPE). We have also identified unique sequence requirements in the 3' terminus of the RNA that can modulate polyadenylation even in the presence of wild-type cis elements. A time course of cytoplasmic polyadenylation in vivo shows that it is an early event of maturation and that it requires protein synthesis within the first 15 min of exposure to progesterone. MPF and cyclin can both induce polyadenylation but, at least with respect to MPF, cannot obviate the requirement for protein synthesis. To identify factors that may be responsible for maturation-specific polyadenylation, we employed extracts from oocytes and unfertilized eggs, the latter of which correctly polyadenylates exogenously added RNA. UV crosslinking demonstrated that an 82 kd protein binds to the U-rich CPE in egg, but not oocyte, extracts. The data suggest that progesterone, either in addition to or through MPF/cyclin, induces the synthesis of a factor during very early maturation that stimulates polyadenylation.(ABSTRACT TRUNCATED AT 250 WORDS)

Infection of the reproductive tract and eggs with Salmonella enterica serovar pullorum in the chicken is associated with suppression of cellular immunity at sexual maturity.

PubMed

Wigley, Paul; Hulme, Scott D; Powers, Claire; Beal, Richard K; Berchieri, Angelo; Smith, Adrian; Barrow, Paul

2005-05-01

Salmonella enterica serovar Pullorum causes persistent infections in laying hens. Splenic macrophages are the main site of persistence. At sexual maturity, numbers of bacteria increase and spread to the reproductive tract, which may result in vertical transmission to eggs or chicks. In this study we demonstrate that both male and female chickens may develop a carrier state following infection but that the increases in bacterial numbers and spread to the reproductive tract are phenomena restricted to hens, indicating that such changes are likely to be related to the onset of egg laying. The immunological responses during the carrier state and through the onset of laying in hens were determined. These indicate that chickens produce both humoral and T-cell responses to infection, but at the onset of laying both the T-cell response to Salmonella and nonspecific responses to mitogenic stimulation fall sharply in both infected and noninfected birds. The fall in T-cell responsiveness coincided with the increase in numbers of Salmonella serovar Pullorum and its spread to the reproductive tract. Three weeks after the onset of egg laying, T-cell responsiveness began to increase and bacterial numbers declined. Specific antibody levels changed little at the onset of laying but increased following the rise in bacterial numbers in a manner reminiscent of a secondary antibody response to rechallenge. These findings indicate that a nonspecific suppression of cellular responses occurs at the onset of laying and plays a major role the ability of Salmonella serovar Pullorum to infect the reproductive tract, leading to transmission to eggs. The loss of T-cell activity at the point of laying also has implications for Salmonella enterica serovar Enteritidis infection and transmission to eggs, along with its control by vaccination offering a "window of opportunity" in which infection may occur.

Biological characteristics of crucian by quantitative inspection method

NASA Astrophysics Data System (ADS)

Chu, Mengqi

2015-04-01

Biological characteristics of crucian by quantitative inspection method Through quantitative inspection method , the biological characteristics of crucian was preliminary researched. Crucian , Belongs to Cypriniformes, Cyprinidae, Carassius auratus, is a kind of main plant-eating omnivorous fish,like Gregarious, selection and ranking. Crucian are widely distributed, perennial water all over the country all have production. Determine the indicators of crucian in the experiment, to understand the growth, reproduction situation of crucian in this area . Using the measured data (such as the scale length ,scale size and wheel diameter and so on) and related functional to calculate growth of crucian in any one year.According to the egg shape, color, weight ,etc to determine its maturity, with the mean egg diameter per 20 eggs and the number of eggs per 0.5 grams, to calculate the relative and absolute fecundity of the fish .Measured crucian were female puberty. Based on the relation between the scale diameter and length and the information, linear relationship between crucian scale diameter and length: y=1.530+3.0649. From the data, the fertility and is closely relative to the increase of age. The older, the more mature gonad development. The more amount of eggs. In addition, absolute fecundity increases with the pituitary gland.Through quantitative check crucian bait food intake by the object, reveals the main food, secondary foods, and chance food of crucian ,and understand that crucian degree of be fond of of all kinds of bait organisms.Fish fertility with weight gain, it has the characteristics of species and populations, and at the same tmes influenced by the age of the individual, body length, body weight, environmental conditions (especially the nutrition conditions), and breeding habits, spawning times factors and the size of the egg. After a series of studies of crucian biological character, provide the ecological basis for local crucian's feeding, breeding, proliferation, fishing, resources protection and management of specific plans.

Initial experience with a donor egg bank.

PubMed

Akin, James W; Bell, Katrina A; Thomas, Diana; Boldt, Jeffrey

2007-08-01

To report on the establishment of a commercial donor egg bank (CryoEggs International, LP) and to present our initial experience from the first four patients to receive eggs. Case report. Private fertility clinic. The four recipient women were aged 43, 43, 40, and 33 years. All had cycle day FSH levels greater than 25 mIU/mL. All were given the option of fresh donor egg IVF but opted to use frozen donor oocytes. Purchased and quarantined frozen donor eggs were thawed and inseminated using intracytoplasmic sperm injection (ICSI). Subsequent embryos were transferred on day 3. Clinical pregnancy as defined by presence of cardiac activity. There was a thawed egg survival rate of 76%, a fertilization rate of 74%, a pregnancy rate (PR) of 50%, with an average of 2.75 embryos per transfer and an implantation rate of 27%. Although very preliminary, these results indicate that more widespread use of frozen donor eggs obtained from a commercial egg bank may be feasible in the future, changing the landscape of donor egg IVF.

Cell cycle in ascidian eggs and embryos.

PubMed

McDougall, Alex; Chenevert, Janet; Lee, Karen W; Hebras, Celine; Dumollard, Remi

2011-01-01

In ascidians the cell cycle machinery has been studied mainly in oocytes while ascidian embryos have been used to dissect the mechanism that controls asymmetric cell division (ACD). Here we overview the most specific and often exceptional points and events in cell cycle control in ascidian oocytes and early embryos. Mature stage IV eggs are arrested at metaphase I due to cytostatic factor (CSF). In vertebrates, unfertilized eggs are arrested at metaphase II by CSF. Meta II-CSF is mediated by the Mos/MEK/MAPK/Erp1 pathway, which inhibits the ubiquitin ligase APC/C(cdc20) preventing cyclin B destruction thus stabilizing MPF activity. CSF is inactivated by the fertilization Ca(2+) transient that stimulates the destruction of Erp1 thus releasing APC/C(cdc20) from inhibition. Although many of the components of CSF are conserved between the ascidian and the vertebrates, the lack of Erp1 in the ascidians (and indeed other invertebrates) is notable since the Mos/MAPK pathway nonetheless mediates Meta I-CSF. Moreover, since the fertilization Ca(2+) transient targets Erp1, it is not clear how the sperm-triggered Ca(2+) transient in ascidians (and again other invertebrates) stimulates cyclin B destruction in the absence of Erp1. Nonetheless, like mammalian eggs, sperm trigger a series of Ca(2+) oscillations that increases the rate of cyclin B destruction and the subsequent loss of MAPK activity leading to meiotic exit in ascidians. Positive feedback from MPF maintains the Ca(2+) oscillations in fertilized ascidian eggs ensuring the eventual loss of MPF stimulating the egg-to-embryo transition. Embryonic cell cycles in the ascidian are highly stereotyped where both the rate of cell division and the orientation of cell division planes are precisely controlled. Three successive rounds of ACD generate two small posterior germ cell precursors at the 64 cell stage. The centrosome-attracting body (CAB) is a macroscopic cortical structure visible by light microscopy that causes these three rounds of ACD. Entry into mitosis activates the CAB causing the whole mitotic spindle to rotate and migrate toward the cortical CAB leading to a highly ACD whereby one small cell is formed that inherits the CAB and approximately 40 maternal postplasmic/PEM RNAs including the germ cell marker vasa.

Insect water-specific aquaporins in developing ovarian follicles of the silk moth Bombyx mori: role in hydration during egg maturation.

PubMed

Maruyama, Mariya; Kambara, Kohei; Naka, Hideshi; Azuma, Masaaki

2015-08-01

Egg formation in terrestrial insects is an absorptive process, accommodated not only by packing proteins and lipids into yolk but also by filling chorions with water. An osmotic swelling of ovarian follicles takes place during oocyte maturation. This study investigated the role of the aquaporin (AQP) water channel in the osmotic uptake of water during oogenesis in the silk moth Bombyx mori Linnaeus, 1758. Using the antibodies that specifically recognize previously characterized AQPs, two water-specific subtypes-AQP-Bom1 and AQP-Bom3-belonging to the Drosophila integral protein (DRIP) and Pyrocoelia rufa integral protein (PRIP) subfamilies of the insect AQP clade, respectively, were identified in the developing ovaries of B. mori. During oocyte growth, Bombyx PRIP was distributed at the oocyte plasma membrane, where it likely plays a role in water uptake and oocyte swelling, and may be responsible for oocyte hydration during fluid absorption by ovarian follicles. During the transition from vitellogenesis to choriogenesis during oocyte maturation, Bombyx DRIP expression became abundant in peripheral yolk granules underlying the oocyte plasma membrane. The restricted DRIP localization was not observed in non-diapause-destined follicles, where DRIP was evenly distributed in medullary yolk granules. There was no difference in PRIP distribution between diapause- and non-diapause-destined follicles. The diapause-destined oocytes encase DRIP protein in the peripheral yolk granules, where DRIP might be inert. This would be reflected in the metabolic arrest associated with diapause after fertilization and egg oviposition. © 2015 Marine Biological Laboratory.

Developmental study of mercury effects on the fruit fly (Drosophila melanogaster).

PubMed

Abnoos, Hamideh; Fereidoni, Masoud; Mahdavi-Shahri, Naser; Haddad, Farhang; Jalal, Razieh

2013-03-01

Environmental pollution caused by heavy metals such as mercury is one of the most important human problems. It might have severe teratogenic effects on embryonic development. Some pharmacological and physiological aspects of fruit flies (Drosophila melanogaster) are similar to humans. So the stages of egg to adult fruit fly, as a developmental model, were employed in the study. Wild adult insects were maintained in glass dishes containing standard medium at 25 °C in complete darkness. Five pairs of 3-day old flies were then transferred to standard culture dishes containing different concentrations of mercury ion. They were removed after 8 hours. We considered the following: The rate of larvae becoming pupae and pupae to adults; the time required for the development; the hatching rate in the second generation without mercury in the culture; the morphometric changes during development in both length and width of the eggs through two generations; larvae, pupae and adult thorax length and width. The results showed that mercury in culture (20-100 mg/l) increase the duration of larvae (p<0.01) and pupae (p<0.01) development, the rate of larvae becoming pupae (p<0.001); pupae maturation (p<0.05), the hatching rate (p<0.01), the length (p<0.05) and width of larvae (p<0.01) and pupae (p<0.001) and the length in the adult thorax (p<0.01) decreased significantly. There was no effect upon the size of eggs. There were also no larvae hatching in concentrations of 200 mg/l of mercury. Negative effects of mercury as a heavy metal are possibly due to the interference of this metal in cellular signaling pathways, such as: Notch signaling and protein synthesis during the period of development. Since it bonds chemically with the sulfur hydride groups of proteins, it causes damage to the cell membrane and decreases the amount of RNA. This is the cause of failure of many enzyme mechanisms.

[Ovarian development and analysis of mating effects on ovary maturation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae)].

PubMed

Dossi, Fábio C A; Cônsoli, Fernando L

2010-01-01

As many other insects with a restricted diet, the citrus psyllid Diaphorina citri Kuwayama, which vector the causing agent of the Huanglongbing, the bacteria Candidatus Liberibacter spp., is intimately associated with symbiotic microorganisms. These mutualist symbionts play a key role on their host nutritional ecology, and are vertically transmitted to the progeny. However, despite the role symbionts play on host development and reproduction, and the growing opportunities of exploitation of the association insect-symbiont to control insect vectored-pathogens, there are very few studies on the host reproductive biology and on the symbiont transovarial transmission. Therefore, we aimed at analyzing the ovary development during D. citri adulthood, and at verifying for the mating requirement as a trigger to initiate ovary development. Newly-emerged D. citri females were grouped as virgin or mated and ovary development was observed during adulthood. Newly-emerged females have immature ovaries, and ovaries remain without any mature eggs until females mate. Once female mates, the vitellogenesis synthesis and uptake are estimulated, and oocytes are quickly developed. Oocytes maturation in ovarioles is metachronic, with only one oocyte developing at a time in each oogenic cycle. Morphological observations of the reproductive system including the ovaries and spermatheca, after the first cluster of eggs is laid, indicated D. citri is polyandrous, and may require multiple mating to develop additional oogenic maturation cycles.

Calcium Signaling enhancement during oocyte maturation

NASA Astrophysics Data System (ADS)

Jung, Peter; Ullah, Ghanim; Machaca, Khaled

2006-03-01

A Ca2+ signal with a special spatial and temporal characteristic universally removes cell-cycle arrest after fertilization of a mature egg cell. The Ca2+ signal is characterized by a fast rise of intracellular Ca2+ and a slow decay on the time scale of minutes. We use computational modeling of Ca2+ release on the microscale (Ca2+ puffs) and cell-scale in conjunction with experimental knowledge of the changes in the Ca2+ signaling apparatus during oocyte maturation and changing signaling patterns to explore the relationship between organization and sensitivity of IP3 receptors and SERCA pumps and the resulting signaling patterns. We hypothesize that potentiation of the IP3 receptors during oocyte maturation is the main cause for the differentiation in the signaling patterns.

Egg positive rate of Enterobius vermicularis of primary school children in Geoje island

PubMed Central

Kim, Bong Jin; Lee, Bo Young; Chung, Hyun Kee; Lee, Young Sun; Lee, Kun Hee; Chung, Hae Jin

2003-01-01

The status of pinworm (Enterobius vermicularis) egg positive rate of primary school children in Geoje island was investigated by using adhesive cellotape anal swap method, in September, 2002. Total egg positive rates of E. vermicularis were 9.8% (74/754) and those of male and female were 10.8% and 8.7%, respectively. Among three schools examined, Myeongsa primary school showed the highest egg positive rate (12.6%) followed by Yeoncho [9.8% (26/266)] and Geoje [9.1% (35/385)]. As for the age groups, the 2nd grade had the highest egg positive rate (15.3%), whereas the 5th grade showed the lowest egg positive rate (2.6%). The above result led us to confirm that the egg positive rates of E. vermicularis in primary school children in Geoje island were not significantly different from the those in the whole country including urban and rural areas, showing more than 10%. PMID:12666734

The role of the actin cytoskeleton in calcium signaling in starfish oocytes.

PubMed

Santella, Luigia; Puppo, Agostina; Chun, Jong Tai

2008-01-01

Ca2+ is the most universal second messenger in cells from the very first moment of fertilization. In all animal species, fertilized eggs exhibit massive mobilization of intracellular Ca2+ to orchestrate the initial events of development. Echinoderm eggs have been an excellent model system for studying fertilization and the cell cycle due to their large size and abundance. In preparation for fertilization, the cell cycle-arrested oocytes must undergo meiotic maturation. Studies of starfish oocytes have shown that Ca2+ signaling is intimately involved in this process. Our knowledge of the molecular mechanism of meiotic maturation and fertilization has expanded greatly in the past two decades due to the discovery of cell cycle-related kinases and Ca2+-mobilizing second messengers. However, the molecular details of their actions await elucidation of other cellular elements that assist in the creation and transduction of Ca2+ signals. In this regard, the actin cytoskeleton, the receptors for second messengers and the Ca2+-binding proteins also require more attention. This article reviews the physiological significance and the mechanism of intracellular Ca2+ mobilization in starfish oocytes during maturation and fertilization.

Scrambled eggs: Proteomic portraits and novel biomarkers of egg quality in zebrafish (Danio rerio)

PubMed Central

Yilmaz, Ozlem; Patinote, Amélie; Nguyen, Thao Vi; Com, Emmanuelle; Lavigne, Regis; Pineau, Charles; Sullivan, Craig V.; Bobe, Julien

2017-01-01

Egg quality is a complex biological trait and a major determinant of reproductive fitness in all animals. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading biomedical model for early development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were sampled immediately after spawning and used to create pooled or replicated sample sets whose protein extracts were subjected to different levels of fractionation before liquid chromatography and tandem mass spectrometry. Obtained spectra were searched against a zebrafish proteome database and detected proteins were annotated, categorized and quantified based on normalized spectral counts. Manually curated and automated enrichment analyses revealed poor quality eggs to be deficient of proteins involved in protein synthesis and energy and lipid metabolism, and of some vitellogenin products and lectins, and to have a surfeit of proteins involved in endo-lysosomal activities, autophagy, and apoptosis, and of some oncogene products, lectins and egg envelope proteins. Results of pathway and network analyses suggest that this aberrant proteomic profile results from failure of oocytes giving rise to poor quality eggs to properly transit through final maturation, and implicated Wnt signaling in the etiology of this defect. Quantitative comparisons of abundant proteins in good versus poor quality eggs revealed 17 candidate egg quality markers. Thus, the zebrafish egg proteome is clearly linked to embryo developmental potential, a phenomenon that begs further investigation to elucidate the root causes of poor egg quality, presently a serious and intractable problem in livestock and human reproductive medicine. PMID:29145436

Scrambled eggs: Proteomic portraits and novel biomarkers of egg quality in zebrafish (Danio rerio).

PubMed

Yilmaz, Ozlem; Patinote, Amélie; Nguyen, Thao Vi; Com, Emmanuelle; Lavigne, Regis; Pineau, Charles; Sullivan, Craig V; Bobe, Julien

2017-01-01

Egg quality is a complex biological trait and a major determinant of reproductive fitness in all animals. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading biomedical model for early development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were sampled immediately after spawning and used to create pooled or replicated sample sets whose protein extracts were subjected to different levels of fractionation before liquid chromatography and tandem mass spectrometry. Obtained spectra were searched against a zebrafish proteome database and detected proteins were annotated, categorized and quantified based on normalized spectral counts. Manually curated and automated enrichment analyses revealed poor quality eggs to be deficient of proteins involved in protein synthesis and energy and lipid metabolism, and of some vitellogenin products and lectins, and to have a surfeit of proteins involved in endo-lysosomal activities, autophagy, and apoptosis, and of some oncogene products, lectins and egg envelope proteins. Results of pathway and network analyses suggest that this aberrant proteomic profile results from failure of oocytes giving rise to poor quality eggs to properly transit through final maturation, and implicated Wnt signaling in the etiology of this defect. Quantitative comparisons of abundant proteins in good versus poor quality eggs revealed 17 candidate egg quality markers. Thus, the zebrafish egg proteome is clearly linked to embryo developmental potential, a phenomenon that begs further investigation to elucidate the root causes of poor egg quality, presently a serious and intractable problem in livestock and human reproductive medicine.

Adaptation of the egg of the desert beetle, Microdera punctipennis (Coleoptera: Tenebrionidae), to arid environment.

PubMed

Wang, Yan; Shi, Meng; Hou, Xiaojuan; Meng, Shanshan; Zhang, Fuchun; Ma, Ji

2014-01-01

Microdera punctipennis Kaszab (Coleoptera: Tenebrionidae) is an endemic species in Guerbantonggut desert in China. To explore the ways that M. punctipennis egg adapts to dry desert environment, morphological characteristics of the egg was investigated along with the egg of the nondesert beetle Tenebrio molitor (Coleoptera: Tenebrionidae). Water loss rate and survival rate of these eggs under different dry treatments (relative humidity0, 10, and 20%) were measured to evaluate the desiccation resistance of the eggs at different developmental stages (day 0, 2, and 5 eggs). Our results showed that the 50-egg weight in T. molitor was heavier than M. punctipennis, while the 50-first-instar larva weight in T. molitor was almost the same as in M. punctipennis. The water loss rate of M. punctipennis egg under dry conditions was significantly lower than T. molitor, and the egg survival rate was significantly higher than T. molitor. The estimated developmental threshold temperature of M. punctipennis egg was 18.30°C, and the critical thermal maximum of M. punctipennis egg is above 39°C. These features partly account for the adaptability of M. punctipennis to desert environment in egg stage. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Activation of dormant ovarian follicles to generate mature eggs.

PubMed

Li, Jing; Kawamura, Kazuhiro; Cheng, Yuan; Liu, Shuang; Klein, Cynthia; Liu, Shu; Duan, En-Kui; Hsueh, Aaron J W

2010-06-01

Although multiple follicles are present in mammalian ovaries, most of them remain dormant for years or decades. During reproductive life, some follicles are activated for development. Genetically modified mouse models with oocyte-specific deletion of genes in the PTEN-PI3K-Akt-Foxo3 pathway exhibited premature activation of all dormant follicles. Using an inhibitor of the Phosphatase with TENsin homology deleted in chromosome 10 (PTEN) phosphatase and a PI3K activating peptide, we found that short-term treatment of neonatal mouse ovaries increased nuclear exclusion of Foxo3 in primordial oocytes. After transplantation under kidney capsules of ovariectomized hosts, treated follicles developed to the preovulatory stage with mature eggs displaying normal epigenetic changes of imprinted genes. After in vitro fertilization and embryo transfer, healthy progeny with proven fertility were delivered. Human ovarian cortical fragments from cancer patients were also treated with the PTEN inhibitor. After xeno-transplantation to immune-deficient mice for 6 months, primordial follicles developed to the preovulatory stage with oocytes capable of undergoing nuclear maturation. Major differences between male and female mammals are unlimited number of sperm and paucity of mature oocytes. Thus, short-term in vitro activation of dormant ovarian follicles after stimulation of the PI3K-Akt pathway allows the generation of a large supply of mature female germ cells for future treatment of infertile women with a diminishing ovarian reserve and for cancer patients with cryo-preserved ovaries. Generation of a large number of human oocytes also facilitates future derivation of embryonic stem cells for regenerative medicine.

Maternal characteristics versus egg size and energy density: do stocked lake trout in Lake Ontario experience premature reproductive senescence?

USGS Publications Warehouse

Lantry, B.F.; O'Gorman, R.; Machut, L.S.

2008-01-01

Observations from September 1994 and 1997 collections of hatchery-origin, mature female lake trout (Salvelinus namaycush) from Lake Ontario indicated that egg mass decreased with age, fueling the notion that stocked fish experienced premature reproductive senescence. Supplemental collections during September 2002 and November 2002-2004 were combined with the 1994 and 1997 samples to examine whether sample date or maternal age, body mass, condition (K), egg count, or strain were related to egg mass or energy content (percentage dry mass [%DM]). Body mass was correlated with egg mass for age ≥ 8 lake trout sampled in September, and egg count was correlated with egg mass for September age-6 lake trout only. Within each month, egg mass was not related to K or egg %DM, however, egg %DM was 1.52% greater (P ≤ 0.0247) in November than in September which is equivalent to a 110 cal/g difference. Samples were grouped for the three most abundant strains (Seneca, Superior, and Ontario) after finding no strain or year effects from our 1994 and 1997 samples and based on life history data from the literature and our assessment sampling. Further analysis indicated that September egg masses were greater for fish ages ≤ 6 than for fish ages ≥ 8. The age effect disappeared in November when mean egg mass across all ages (0.078 g) was greater than September means (P < 0.0005) for ages -5 (0.054 g), -6 (0.057 g) and ≥ 8 (0.041 g). Our results indicate that the decrease in egg mass with female age in September was not due to senescence, but to oogenesis being closer to completion in young age-5 and -6 fish than in older individuals.

Predation and Parasitism Rates on Sentinel and Naturally Occurring Egg Masses of the Squash Bug (Hemiptera: Coreidae) in Maryland

USDA-ARS?s Scientific Manuscript database

Seasonal changes in egg predation and parasitism rates on sentinel and naturally occurring (wild) egg masses of the squash bug, Anasa tristis (DeGeer), were evaluated in squash fields in Maryland from June through September in 2013 and 2014. Rates of egg predation and parasitism were significantly ...

Hatching the Cleidoic Egg: The Role of Thyroid Hormones

PubMed Central

De Groef, Bert; Grommen, Sylvia V.H.; Darras, Veerle M.

2013-01-01

A major life stage transition in birds and other oviparous sauropsids is the hatching of the cleidoic egg. Not unlike amphibian metamorphosis, hatching in these species can be regarded as a transition from a relatively well-protected “aqueous” environment to a more hazardous and terrestrial life outside the egg, a transition in which thyroid hormones (THs) (often in concert with glucocorticoids) play an important role. In precocial birds such as the chicken, the perihatch period is characterized by peak values of THs. THs are implicated in the control of muscle development, lung maturation and the switch from chorioallantoic to pulmonary respiration, yolk sac retraction, gut development and induction of hepatic genes to accommodate the change in dietary energy source, initiation of thermoregulation, and the final stages of brain maturation as well as early post-hatch imprinting behavior. There is evidence that, at least for some of these processes, THs may have similar roles in non-avian sauropsids. In altricial birds such as passerines on the other hand, THs do not rise significantly until well after hatching and peak values coincide with the development of endothermy. It is not known how hatching-associated processes are regulated by hormones in these animals or how this developmental mode evolved from TH-dependent precocial hatching. PMID:23755041

Medullary bone in fossils: function, evolution and significance in growth curve reconstructions of extinct vertebrates.

PubMed

Prondvai, E

2017-03-01

Medullary bone (MB) is a special endosteal tissue forming in the bones of female birds during egg laying to serve as a labile calcium reservoir for building the hard eggshell. Therefore, the presence of MB reported in multiple nonavian dinosaurs is currently considered as evidence that those specimens were sexually mature females in their reproductive period. This interpretation has led to further inferences on species-specific growth strategies and related life-history aspects of these extinct vertebrates. However, a few studies questioned the reproductive significance of fossil MB by either regarding the tissue pathological or attributing alternative functions to it. This study reviews the general inferences on extinct vertebrates and discusses the primary role, distribution, regulation and adaptive significance of avian MB to point out important but largely overlooked uncertainties and inconsistencies in this matter. Emerging discordancy is demonstrated when the presence of MB vs. trade-off between growth and reproduction is used for interpreting dinosaurian growth curves. Synthesis of these data suggests that fossil MB was related to high calcium turnover rates but not exclusively to egg laying. Furthermore, revised application of Allosaurus growth data by modelling individual-based growth curves implies a much higher intraspecific variability in growth strategies, including timing of sexual maturation, than usually acknowledged. New hypotheses raised here to resolve these incongruences also propose new directions of research on the origin and functional evolution of this curious bone tissue. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Hypoxia Treatment of Callosobruchus maculatus Females and Its Effects on Reproductive Output and Development of Progeny Following Exposure.

PubMed

Yan, Yan; Williams, Scott B; Baributsa, Dieudonne; Murdock, Larry L

2016-06-17

Modified atmospheres present a residue-free alternative to fumigants for controlling postharvest pests of grain during storage. How sub-lethal applications of this method affects the reproductive fitness of target pests, however, is still not fully understood. We examined how low levels of ambient oxygen influence the reproduction of the female cowpea bruchid (Callosobruchus maculatus), a pest of cowpea. We used three low-oxygen atmospheres-2%, 5% and 10% (v/v) oxygen-and observed their effects on: (1) the number of eggs laid by bruchids compared to insects held in normoxic (~20% oxygen) conditions; (2) the total number of eggs laid; and (3) the number of progeny that reached maturity. Low oxygen did not significantly affect the number of eggs laid during 48 or 72 h of exposure, but 2% and 5% oxygen did negatively affected total egg production. Increasing the exposure time from 48 to 72 h further depressed lifetime reproductive output. Maternal and egg exposure to hypoxia reduced the number of progeny that reached adulthood. Lower adult emergence was observed from eggs laid under low oxygen and longer exposure times. These data demonstrate that hermetic conditions depress the egg-laying behavior of cowpea bruchids and the successful development of their progeny.

Hypoxia Treatment of Callosobruchus maculatus Females and Its Effects on Reproductive Output and Development of Progeny Following Exposure

PubMed Central

Yan, Yan; Williams, Scott B.; Baributsa, Dieudonne; Murdock, Larry L.

2016-01-01

Modified atmospheres present a residue-free alternative to fumigants for controlling postharvest pests of grain during storage. How sub-lethal applications of this method affects the reproductive fitness of target pests, however, is still not fully understood. We examined how low levels of ambient oxygen influence the reproduction of the female cowpea bruchid (Callosobruchus maculatus), a pest of cowpea. We used three low-oxygen atmospheres—2%, 5% and 10% (v/v) oxygen—and observed their effects on: (1) the number of eggs laid by bruchids compared to insects held in normoxic (~20% oxygen) conditions; (2) the total number of eggs laid; and (3) the number of progeny that reached maturity. Low oxygen did not significantly affect the number of eggs laid during 48 or 72 h of exposure, but 2% and 5% oxygen did negatively affected total egg production. Increasing the exposure time from 48 to 72 h further depressed lifetime reproductive output. Maternal and egg exposure to hypoxia reduced the number of progeny that reached adulthood. Lower adult emergence was observed from eggs laid under low oxygen and longer exposure times. These data demonstrate that hermetic conditions depress the egg-laying behavior of cowpea bruchids and the successful development of their progeny. PMID:27322332

Increase of fecundity by probiotic administration in zebrafish (Danio rerio).

PubMed

Gioacchini, Giorgia; Maradonna, Francesca; Lombardo, Francesco; Bizzaro, Davide; Olivotto, Ike; Carnevali, Oliana

2010-12-01

It is well known established that reproduction is sensitive to the state of energy reserves, and that there is a balance between energy homeostasis and fertility. In this view, this study examined the effects of the probiotic Lactobacillus rhamnosus, as a feed additive, on zebrafish (Danio rerio) fecundity. Ten days of probiotic treatment modulate the gene expression of neuropeptide hormones and metabolic signals, such as kiss1, kiss2 and leptin both at the CNS level and at the peripheral level. The increase in fecundity brought about by the probiotic was demonstrated by the higher number of ovulated eggs in vivo and by the higher germinal vesicle breakdown rate obtained with the in vitro maturation assay. The increase in oocyte maturation was associated with increased transcription of genes coding for signals which induce the maturation phase, such as lhcgr, cbr1l, and paqr8 genes, concomitant with a decreased transcription of genes coding for local factors which prevent oocyte maturation, such as tgfb1, gdf9, and bmp15. In conclusion, all these findings highlight the action of L. rhamnosus both on the endocrine system and at the local level by inducing oocyte maturation. The significance of the results herein obtained underlined the importance of diet in the reproductive process, supporting the hypothesis that feed additives can improve fecundity. Considering that the zebrafish has been clearly established as a vertebrate model for biomedical research, these results support the potentiality of feed additives such as probiotics, frequently used in the human diet, as a new technology to improve reproduction in all vertebrates, including humans.

Progressive chorion morphology during egg development in Samia ricini (Donovan).

PubMed

Renthlei, Collin Z; Raghuvarman, Arumugam; Kharbuli, Besterwell; Dey, Sudip

2010-03-01

The egg of Samia ricini (Donovan), is oval or laterally flattened ellipsoid, freshly laid eggs are candid white while the chorion is colorless and semi-transparent. The surface of the chorion is covered with network patterns of polygons and their shapes are common in the whole surface region. The boundaries between polygons made ridges had distinct acropyles at three-cell junctions. The numbers of aeropyles are variable according to their structures both in the lateral flat and marginal regions. During the course of egg development, no significant structural changes were observed in either the polygonal structures or the overall morphology of the egg. However, the size of the aeropyles kept on changing as the egg matures. The aeropyle increases initially upto day-9 of egg development and then decreases as it approach hatching. Lines of weaknesses were not observed at time of hatching or close to it. Hatching process of the newly emerge larvae are through gnawing. The larva eats their way out through the chorion membrane mostly from the anterior region. Egg buster or spine which aid in hatching are not present in the newly emerge larvae.This article was published online on 25 September 2009. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 6 January 2010.

Dungeness crab, Cancer magister, do not extrude eggs annually in southeastern Alaska: An in situ study

USGS Publications Warehouse

Swiney, K.M.; Shirley, Thomas C.; Taggart, S. James; O'Clair, Charles E.

2003-01-01

The reproductive biology of female Dungeness crabs was studied with crab-pot and dive-transect sampling in five bays within or near Glacier Bay National Park and Preserve, southeastern Alaska, in April and September yearly from 1992 to 1998. A large percentage of nonovigerous, mature females was found in April, a time when females were expected to be brooding eggs that hatch in May and June. Our study examined differences between ovigerous and nonovigerous females collected in April and September samples to corroborate our previous laboratory study in which we found nonannual egg extrusion among Dungeness crabs. Seasonal differences in the catches of ovigerous and nonovigerous females, crab sizes, shell condition, and appendage injury were examined. Additionally, all crabs collected from two bays were tagged beginning in the fall of 1995; tagging was conducted twice annually. Our pot and dive data indicate that females, particularly larger ones, do not extrude eggs annually. Larger females have lower molting probabilities, which limits mating potential and increases reliance on stored sperm. The tagging study confirmed that at least some females do not extrude eggs in one year and then extrude eggs at a later time without molting, thus skipping at least one reproductive season. A reproductive cycle of Dungeness crabs in Alaska is introduced which includes earlier egg extrusion by larger females and nonannual egg extrusion.

In vitro storage of unfertilized eggs of the Eurasian perch and its effect on egg viability rates and the occurrence of larval malformations.

PubMed

Samarin, A M; Żarski, D; Palińska-Żarska, K; Krejszeff, S; Blecha, M; Kucharczyk, D; Policar, T

2017-01-01

Ova ageing is the most important factor affecting fish egg quality after ovulation. Long-term storage of fish ova, using cryopreservation and vitrification techniques, has been unsuccessful to date. Instead, short-term in vitro ova storage has been used successfully and optimized in some cultured fish species. In vitro ova storage can drastically improve mass production of larvae and juveniles in the hatcheries by providing the possibility of the synchronous artificial fertilization for different females. To study how long unfertilized eggs of Eurasian perch (Perca fluviatilis L.) can retain their fertilizing ability after stripping, eggs were stored at temperatures of 4°C, 8°C and 12°C for 72 h post-stripping (HPS). The stored eggs of four female perch were separately fertilized at 0 h (i.e. control eggs fertilized before storage) and at 6-hour intervals during the experimental period of 72 h. The embryos reaching the eyed-egg and hatched-larvae stages, eyed-egg mortality and larval malformation rates were recorded as indices of egg quality. The results indicated that the maximum eyed eggs and hatched larvae (86% and 63%, respectively) were observed for eggs fertilized immediately after stripping, whereas the storage of the eggs at 4°C for 48 HPS decreased the eyed-egg and hatched-larvae rates to 46% and 17%, respectively. The use of a higher storage temperature resulted in a more rapid decrease in egg viability: eyed-egg and hatched-larvae rates of 23% and 9%, respectively, were obtained after 48 HPS storage at 8°C and 2% and 1% for eggs stored at 12°C. Eyed-egg mortality and larval malformation rates were not significantly affected by post-stripping ova ageing for at least up to 36 h. Thereafter, both values increased significantly and were measured to be the highest in the most aged ova. The present study demonstrated that stripped Eurasian perch eggs can be stored for at least 12 h at 4°C to 12°C without a significant reduction in their quality.

Field infestation of rambutan fruits by internal-feeding pests in Hawaii.

PubMed

McQuate, G T; Follett, P A; Yoshimoto, J M

2000-06-01

More than 47,000 mature fruits of nine different varieties of rambutan (Nephelium lappaceum L.) were harvested from orchards in Hawaii to assess natural levels of infestation by tephritid fruit flies and other internal feeding pests. Additionally, harvested, mature fruits of seven different rambutan varieties were artificially infested with eggs or first-instars of Mediterranean fruit fly, Ceratitis capitata (Wiedemann), or oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) to assess host suitability. When all varieties were combined over two field seasons of sampling, fruit infestation rates were 0.021% for oriental fruit fly, 0.097% for Cryptophlebia spp. (Lepidoptera: Tortricidae), and 0.85% for pyralids (Lepidoptera). Species of Cryptophlebia included both C. illepida (Butler), the native Hawaiian species, and C. ombrodelta (Lower), an introduced species from Australia. Cryptophlebia spp. had not previously been known to attack rambutan. The pyralid infestation was mainly attributable to Cryptoblabes gnidiella (Milliere), a species also not previously recorded on rambutan in Hawaii. Overall infestation rate for other moths in the families Blastobasidae, Gracillariidae, Tineidae, and Tortricidae was 0.061%. In artificially infested fruits, both species of fruit fly showed moderately high survivorship for all varieties tested. Because rambutan has such low rates of infestation by oriental fruit fly and Cryptophlebia spp., the two primary internal-feeding regulatory pests of rambutan in Hawaii, it may be amenable to the alternative treatment efficacy approach to postharvest quarantine treatment.

Multiple vitellogenins and product yolk proteins in European sea bass (Dicentrarchus labrax): Molecular characterization, quantification in plasma, liver and ovary, and maturational proteolysis.

PubMed

Yilmaz, Ozlem; Prat, Francisco; Ibáñez, A Jose; Köksoy, Sadi; Amano, Haruna; Sullivan, Craig V

2016-01-01

Three complete vitellogenin (Vtg) polypeptides of European sea bass (Dicentrarchus labrax), an acanthomorph teleost spawning pelagic eggs in seawater, were deduced from cDNA and identified as VtgAa, VtgAb and VtgC based on current Vtg nomenclature and phylogeny. Label free quantitative mass spectrometry verified the presence of the three sea bass Vtgs or their product yolk proteins (YPs) in liver, plasma and ovary of postvitellogenic females. As evidenced by normalized spectral counts, VtgAb-derived protein was 2- to 5-fold more abundant, depending on sample type, than for VtgAa, while VtgC-derived protein was less abundant, albeit only 3-fold lower than for VtgAb in the ovary. Western blotting with Vtg type-specific antisera raised against corresponding gray mullet (Mugil cephalus) lipovitellins (Lvs) detected all three types of sea bass Vtg in the blood plasma of gravid females and/or estrogenized males and showed that all three forms of sea bass Lv undergo limited partial degradation during oocyte maturation. The comparatively high levels of VtgC-derived YPs in fully-grown oocytes and the maturational proteolysis of all three types of Lv differ from what has been reported for other teleosts spawning pelagic eggs in seawater but are similar to recent findings for two species of North American Moronidae, the striped bass (Morone saxatilis) and white perch (Morone americana), which spawn pelagic and demersal eggs, respectively in fresh water. Together with the high Vtg sequence homologies and virtually identical structural features of each type of Vtg between species, these findings indicate that the moronid multiple Vtg systems do not substantially vary with reproductive environment. Copyright © 2015 Elsevier Inc. All rights reserved.

Reproductive ecology, spawning behavior, and juvenile distribution of Mountain Whitefish in the Madison River, Montana

USGS Publications Warehouse

Boyer, Jan K.; Guy, Christopher S.; Webb, Molly A. H.; Horton, Travis B.; McMahon, Thomas E.

2017-01-01

Mountain Whitefish Prosopium williamsoni were historically common throughout much of the U.S. Intermountain West. However, within the last decade Mountain Whitefish have exhibited population-level declines in some rivers. In the Madison River, Montana, anecdotal evidence indicates Mountain Whitefish abundance has declined and the population is skewed toward larger individuals, which is typically symptomatic of recruitment problems. Describing reproductive development, spawning behavior, and juvenile distribution will form a foundation for investigating mechanisms influencing recruitment. We collected otoliths and gonadal samples from fish of all size-classes to characterize fecundity, age at maturity, and spawning periodicity. We implanted radio tags in mature Mountain Whitefish and relocated tagged fish in autumn 2012–2014. Timing of spawning was determined from spawning status of captured females and from density of eggs collected on egg mats. In spring 2014, we seined backwater and channel sites to describe age-0 whitefish distribution. Mountain Whitefish were highly fecund (18,454 eggs/kg body weight) annual spawners, and age at 50% maturity was 2.0 years for males and 2.6 years for females. In 2013 and 2014, spawning occurred between the third week of October and first week of November. During spawning, spawning adults and collected embryos were concentrated in the downstream 26 km of the study site, a reach characterized by a complex, braided channel. This reach had the highest CPUE of age-0 Mountain Whitefish, and the percentage of spawning adults in the 25 km upstream from a sampling site was positively associated with juvenile CPUE. Within this reach, age-0 Mountain Whitefish were associated with silt-laden backwater and eddy habitats. Future investigations on mechanisms influencing recruitment should be focused on the embryological phase and age-0 fish.

Improvements in IVF in women of advanced age.

PubMed

Gleicher, Norbert; Kushnir, Vitaly A; Albertini, David F; Barad, David H

2016-07-01

Women above age 40 years in the US now represent the most rapidly growing age group having children. Patients undergoing in vitro fertilization (IVF) are rapidly aging in parallel. Especially where egg donations are legal, donation cycles, therefore, multiply more rapidly than autologous IVF cycles. The donor oocytes, however, are hardly ever a preferred patient choice. Since with use of own eggs, live birth rates decline with advancing age but remain stable (and higher) with donor eggs, older patients always face the difficult and very personal choice between poorer chances with own and better chances with donor oocytes. Physician contribution to this decision should in our opinion be restricted to accurate outcome information for both options. Achievable pregnancy and live birth rates in older women are, however, frequently underestimated, thereby mistakenly biasing fertility providers, private insurance companies and even regulatory government agencies. Restriction on access to IVF for older women is then often the consequence. In this review, we summarize the limited published data on best treatments of 'older' ovaries, while also addressing treatment approaches that should be avoided in older women. This focused review, therefore, to a degree is subjective. Research addressing aging ovaries in IVF has been disappointingly sparse, and has in our opinion too heavily concentrated on methods of embryo selection (ES), which, especially in older women, not only fail to improve IVF outcomes, but actually, negatively affect live birth chances. We conclude that, aside from breakthroughs in gamete creation, only pharmacological interventions into early (small growing follicle stages) follicle maturation will offer new potential to positively impact oocyte and embryo quality and, therefore, IVF outcomes. Research, therefore, should be accordingly redirected. © 2016 Society for Endocrinology.

Influence of the indirect effects of guppies on life-history evolution in Rivulus hartii.

PubMed

Walsh, Matthew R; Reznick, David N

2010-06-01

Early theories of life-history evolution predict that increased predation on young/small individuals selects for delayed maturation and decreased reproductive effort, but such theory only considers changes in mortality. Predators reduce prey abundance and increase food to survivors. Theory that incorporates such indirect effects yields different predictions. Trinidadian killifish, Rivulus hartii, inhabit communities with and without guppies. Guppies prey on young Rivulus and Rivulus densities decline and growth rates increase when guppies are present. Prior work showed that Rivulus phenotypes from communities with guppies matured earlier and had higher fecundity, consistent with theories that incorporate indirect effects. Here we examined the genetic basis of these differences by rearing 2nd generation, laboratory-born Rivulus from sites with and without guppies under two food levels that match natural differences in growth. Many locality x food interactions were significant, often reversing the relationship between communities. Such interactions imply that there are fitness trade-offs associated with adaptation to high or low resource environments. On high food, Rivulus from localities with guppies matured earlier, produced many small eggs, and exhibited increased reproductive investment; these differences reversed on low food. Our results suggest that indirect effects mold Rivulus evolution and thereby highlight connections between community processes and evolutionary change.

The efficiency of a donor-recipient program using infertile donors' egg cryo-banking: a Brazilian reality.

PubMed

Figueira, Rita de Cássia Sávio; Setti, Amanda S; Braga, Daniela P A F; Iaconelli, Assumpto; Borges, Edson

2014-08-01

To determine whether Brazilian egg donation treatment outcomes with oocytes donated from infertile couples are equivalent to those obtained worldwide with oocytes donated from fertile egg-donors. In this descriptive study, egg-donation cycles from 259 women, performed from January 2009 to July 2013, were evaluated. Oocytes were obtained from patients undergoing ICSI who decided to donate their surplus oocytes. We described the survival, fertilization, blastocyst, implantation and pregnancy rates obtained in our infertile donor-recipient program. In addition, we described the results obtained in previous published studies. In our egg-donation program we obtained a fertilization rate of 72.9 %, a blastocyst formation rate of 53.2 %, an implantation rate of 31.1 % and the estimated clinical pregnancy rate per warmed oocyte was 5.4 %. The analyzed studies, performed between 2008 and 2013, included varying numbers of egg-donors (range: 20-600), warmed oocytes (range: 123-3826) and survival rates (range: 85.6-92.5 %). Fertilization rates ranged from 74.2 to 87.0 %, blastocyst formation rate ranged from 41.3 % to 68.0 %, implantation rates ranged from 24.7 % to 55.3 % and the clinical pregnancy rate per warmed oocyte ranged from 3.9 % to 9.8 %. New and reassuring information derived from our egg-donation program demonstrates outcomes similar to those reported for other egg donation programs.

Impact of the egg parasitoid, gryon pennsylvanicum (Hymenoptera: Scelionidae), on sentinel and wild egg masses of the squash bug (Hemiptera: Coreidae) in Maryland

USDA-ARS?s Scientific Manuscript database

Seasonal changes in egg predation and parasitism rates on sentinel and naturally occurring (wild) egg masses of the squash bug, Anasa tristis (DeGeer), were evaluated in squash fields in Maryland from June through September in 2013 and 2014. Rates of egg predation and parasitism were significantly...

Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction.

PubMed

Brosset, Pablo; Lloret, Josep; Muñoz, Marta; Fauvel, Christian; Van Beveren, Elisabeth; Marques, Virginie; Fromentin, Jean-Marc; Ménard, Frédéric; Saraux, Claire

2016-10-01

Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy ( Engraulis encrasicolus ) and sardine ( Sardina pilchardus ) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions.

Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction

PubMed Central

Lloret, Josep; Muñoz, Marta; Fauvel, Christian; Van Beveren, Elisabeth; Marques, Virginie; Fromentin, Jean-Marc; Ménard, Frédéric; Saraux, Claire

2016-01-01

Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions. PMID:27853538

Energy allocation during the maturation of adults in a long-lived insect: implications for dispersal and reproduction.

PubMed

David, G; Giffard, B; van Halder, I; Piou, D; Jactel, H

2015-10-01

Energy allocation strategies have been widely documented in insects and were formalized in the context of the reproduction process by the terms 'capital breeder' and 'income breeder'. We propose here the extension of this framework to dispersal ability, with the concepts of 'capital disperser' and 'income disperser', and explore the trade-off in resource allocation between dispersal and reproduction. We hypothesized that flight capacity was sex-dependent, due to a trade-off in energy allocation between dispersal and egg production in females. We used Monochamus galloprovincialis as model organism, a long-lived beetle which is the European vector of the pine wood nematode. We estimated the flight capacity with a flight mill and used the number of mature eggs as a proxy for the investment in reproduction. We used the ratio between dry weights of the thorax and the abdomen to investigate the trade-off. The probability of flying increased with the adult weight at emergence, but was not dependent on insect age or sex. Flight distance increased with age in individuals but did not differ between sexes. It was also positively associated with energy allocation to thorax reserves, which increased with age. In females, the abdomen weight and the number of eggs also increase with age with no negative effect on flight capacity, indicating a lack of trade-off. This long-lived beetle has a complex strategy of energy allocation, being a 'capital disperser' in terms of flight ability, an 'income disperser' in terms of flight performance and an 'income breeder' in terms of egg production.

Etheostoma brevirostrum (Holiday Darter)

USGS Publications Warehouse

Burkhead, Noel M.

2015-01-01

The life history of the Holiday Darter is incompletely known. Only reproductive behavior (Johnston and Shute 1997; Anderson 2009), habitat use, and spawning seasons (Anderson 2009) have been studied. However, based on similarity of life history attributes among snubnose darters (Carney and Burr 1989; Johnston and Haag 1996; Khudamrongsawat et al. 2005), the Holiday darter probably lives 3+ years and matures in the first year. It is likely a benthic omnivore, feeding primarily on chironomid (midge) larvae and other common orders of aquatic insects and occasional microcrustaceans. Spawning occurs from late March to early June, with most activity occurring in April. Based on four females from the Amicalola Creek system, fecundity ranged from 50 to 150 mature eggs, egg sizes ranged from 1.2mm to 1.6mm diameter. The Holiday Darter is an “egg attacher” (sensu Page and Swofford 1984). A spawning female is courted by multiple males, but a dominant (alpha) male aggressively rebuts encroaching males and defends a “roving territory” of the receptive female. The alpha male is the principal spawning partner although satellite males often rush a spawning pair. The receptive female slowly swims along the stream bottom, frequently stopping, apparently to assess substrate attributes, and selects each spawning site where only one or two eggs are spawned. The process is repeated and often covers several meters of stream bottom until the courted female finishes spawning and is abandoned by the alpha male. Water temperatures during spawning in Amicalola Creek and the upper Etowah River ranged 10 to 17° C (Anderson 2009).

Predicting the likelihood of live birth for elective oocyte cryopreservation: a counseling tool for physicians and patients.

PubMed

Goldman, R H; Racowsky, C; Farland, L V; Munné, S; Ribustello, L; Fox, J H

2017-04-01

Can a counseling tool be developed for women desiring elective oocyte cryopreservation to predict the likelihood of live birth based on age and number of oocytes frozen? Using data from ICSI cycles of a population of women with uncompromised ovarian reserve, an evidence-based counseling tool was created to guide women and their physicians regarding the number of oocytes needed to freeze for future family-building goals. Elective oocyte cryopreservation is increasing in popularity as more women delay family building. By undertaking elective oocyte freezing at a younger age, women hope to optimize their likelihood of successful live birth(s) using their thawed oocytes at a future date. Questions often arise in clinical practice regarding the number of cryopreserved oocytes sufficient to achieve live birth(s) and whether or not additional stimulation cycles are likely to result in a meaningful increase in the likelihood of live birth. As relatively few women who have electively cryopreserved oocytes have returned to use them, available data for counseling patients wishing to undergo fertility preservation are limited. A model was developed to determine the proportion of mature oocytes that fertilize and then form blastocysts as a function of age, using women with presumably normal ovarian reserve based on standard testing who underwent ICSI cycles in our program from January, 2011 through March, 2015 (n = 520). These included couples diagnosed exclusively with male-factor and/or tubal-factor infertility, as well as cycles utilizing egg donation. Age-specific probabilities of euploidy were estimated from 14 500 PGS embryo results from an external testing laboratory. Assuming survival of thawed oocytes at 95% for women <36 y and for egg donors, and 85% for women ≥36 y, and 60% live birth rate per transferred euploid blastocyst, probabilities of having at least one, two or three live birth(s) were calculated. First fresh male-factor and/or tubal-factor only autologous ICSI cycles (n = 466) were analyzed using Poisson regression to calculate the probability that a mature oocyte will become a blastocyst based on age. Egg donation cycles (n = 54) were analyzed and incorporated into the model separately. The proportion of blastocysts expected to be euploid was determined using PGS results of embryos analyzed via array comparative genomic hybridization. A counseling tool was developed to predict the likelihood of live birth, based on individual patient age and number of mature oocytes. This study provides an evidence-based model to predict the probability of a woman having at least one, two or three live birth(s) based on her age at egg retrieval and the number of mature oocytes frozen. The model is derived from a surrogate population of ICSI patients with uncompromised ovarian reserve. A user-friendly counseling tool was designed using the model to help guide physicians and patients. The data used to develop the prediction model are, of necessity, retrospective and not based on patients who have returned to use their cryopreserved oocytes. The assumptions used to create the model, albeit reasonable and data-driven, vary by study and will likely vary by center. Centers are therefore encouraged to consider their own blastocyst formation and thaw survival rates when counseling patients. Our model will provide a counseling resource that may help inform women desiring elective fertility preservation regarding their likelihood of live birth(s), how many cycles to undergo, and when additional cycles would bring diminishing returns. None. Not applicable. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Toxicity of pesticide and fertilizer mixtures simulating corn production to eggs of snapping turtles (Chelydra serpentina).

PubMed

de Solla, Shane Raymond; Martin, Pamela Anne; Mikoda, Paul

2011-09-15

Many reptiles oviposit in soils associated with agricultural landscapes. We evaluated the toxicity of a pesticide and fertilizer regime similar to those used in corn production in Ontario on the survivorship of exposed snapping turtle (Chelydra serpentina) eggs. The herbicides atrazine, dimethenamid, and glyphosate, the pyrethroid insecticide tefluthrin, and the fertilizer ammonia, were applied to clean soil, both as partial mixtures within chemical classes, as well as complete mixtures. Eggs were incubated in the soil in a garden plot in which these mixtures were applied at a typical field application rate, and higher rates. Otherwise, the eggs were unmanipulated and were subject to ambient temperature and weather conditions. Eggs were also exposed at male producing temperatures in the laboratory in covered bins in the same soil, where there was less opportunity for loss through volatilization or leaching. Egg mortality was 100% at 10× the typical field application rate of the complete mixture, both with and without tefluthrin. At typical field application rates, hatching success ranged between 91.7 and 95.8%. Eggs exposed only to herbicides were not negatively affected at any application rates. Although fertilizer treatments at typical field application rates did not affect eggs, mortality was remarkably higher at three times this rate, and 100% at higher rates. The frequency of deformities of hatchlings was elevated at the highest application rate of the insecticide tefluthrin. The majority of the toxicity of the mixture was not due to the herbicides or insecticide, but was due to the ammonia fertilizer. At typical field application rates, the chemical regime associated with corn production does not appear to have any detrimental impacts upon turtle egg development; however toxicity dramatically increases if this threshold is passed. Copyright © 2011. Published by Elsevier B.V.

A parasitism-mutualism-predation model consisting of crows, cuckoos and cats with stage-structure and maturation delays on crows and cuckoos

USGS Publications Warehouse

Luo, Yantao; Zhang, Long; Teng, Zhidong; DeAngelis, Donald L.

2018-01-01

In this paper, a parasitism-mutualism-predation model is proposed to investigate the dynamics of multi-interactions among cuckoos, crows and cats with stage-structure and maturation time delays on cuckoos and crows. The crows permit the cuckoos to parasitize their nestlings (eggs) on the crow chicks (eggs). In return, the cuckoo nestlings produce a malodorous cloacal secretion to protect the crow chicks from predation by the cats, which is apparently beneficial to both the crow and cuckoo population. The multi-interactions, i.e., parasitism and mutualism between the cuckoos (nestlings) and crows (chicks), predation between the cats and crow chicks are modeled both by Holling-type II and Beddington-DeAngelis-type functional responses. The existence of positive equilibria of three subsystems of the model are discussed. The criteria for the global stability of the trivial equilibrium are established by the Krein-Rutman Theorem and other analysis methods. Moreover, the threshold dynamics for the coexistence and weak persistence of the model are obtained, and we show, both analytically and numerically, that the stabilities of the interior equilibria may change with the increasing maturation time delays. We find there exists an evident difference in the dynamical properties of the parasitism-mutualism-predation model based on whether or not we consider the effects of stage-structure and maturation time delays on cuckoos and crows. Inclusion of stage structure results in many varied dynamical complexities which are difficult to encompass without this inclusion.

Distributed Egg Production Functions for Meloidogyne arenaria in Grape Varieties and Consideration of the Mechanistic Relationship between Plant and Parasite.

PubMed

Ferris, H; Schneider, S M; Semenoff, M C

1984-04-01

Nematode egg production rates, as mediated by environmental conditions and host status, are important determinants of population development. Rates of egg production by Meloidogyne arenaria varied from 0.48 to 1.0 egg per female per DD (degree days above 10 C) in different grape varieties. The length of the egg production period ranged from 550 to 855 DD where measurable, and was generally longer in those varieties where the production rate was slow. We hypothesize that if a successful infection site is established, a constant number of eggs is produced if favorable environmental conditions prevail. Mechanistic coupling structures between plant growth and nematode population models are formulated. The nematode population influences metabolite supply through its effect on physiological efficiency and also acts as a metabolic sink; the degree of plant physiological stress influences nematode population development by affecting the sex ratio and egg production rates.

Release from meiotic arrest in ascidian eggs requires the activity of two phosphatases but not CaMKII

PubMed Central

Levasseur, Mark; Dumollard, Remi; Chambon, Jean-Philippe; Hebras, Celine; Sinclair, Maureen; Whitaker, Michael; McDougall, Alex

2013-01-01

The fertilising sperm triggers a transient Ca2+ increase that releases eggs from cell cycle arrest in the vast majority of animal eggs. In vertebrate eggs, Erp1, an APC/Ccdc20 inhibitor, links release from metaphase II arrest with the Ca2+ transient and its degradation is triggered by the Ca2+-induced activation of CaMKII. By contrast, many invertebrate groups have mature eggs that arrest at metaphase I, and these species do not possess the CaMKII target Erp1 in their genomes. As a consequence, it is unknown exactly how cell cycle arrest at metaphase I is achieved and how the fertilisation Ca2+ transient overcomes the arrest in the vast majority of animal species. Using live-cell imaging with a novel cyclin reporter to study cell cycle arrest and its release in urochordate ascidians, the closest living invertebrate group to the vertebrates, we have identified a new signalling pathway for cell cycle resumption in which CaMKII plays no part. Instead, we find that the Ca2+-activated phosphatase calcineurin (CN) is required for egg activation. Moreover, we demonstrate that parthenogenetic activation of metaphase I-arrested eggs by MEK inhibition, independent of a Ca2+ increase, requires the activity of a second egg phosphatase: PP2A. Furthermore, PP2A activity, together with CN, is required for normal egg activation during fertilisation. As ascidians are a sister group of the vertebrates, we discuss these findings in relation to cell cycle arrest and egg activation in chordates. PMID:24194472

A minimally invasive method for extraction of sturgeon oocytes

USGS Publications Warehouse

Candrl, James S.; Papoulias, Diana M.; Tillitt, Donald E.

2010-01-01

Fishery biologists, hatchery personnel, and caviar fishers routinely extract oocytes from sturgeon (Acipenseridae) to determine the stage of maturation by checking egg quality. Typically, oocytes are removed either by inserting a catheter into the oviduct or by making an incision in the body cavity. Both methods can be time-consuming and stressful to the fish. We describe a device to collect mature oocytes from sturgeons quickly and effectively with minimal stress on the fish. The device is made by creating a needle from stainless steel tubing and connecting it to a syringe with polyvinyl chloride tubing. The device is filled with saline solution or water, the needle is inserted into the abdominal wall, and eggs are extracted from the fish. Using this device, an oocyte sample can be collected in less than 30 s. Such sampling leaves a minute wound that heals quickly and does not require suturing. The extractor device can easily be used in the field or hatchery, reduces fish handling time, and minimizes stress.

Variation in incubation periods and egg metabolism in mallards: Intrinsic mechanisms to promote hatch synchrony

USGS Publications Warehouse

MacCluskie, Margaret C.; Flint, Paul L.; Sedinger, James S.

1997-01-01

We investigated factors affecting incubation time and metabolic rates of Mallard (Anas platyrhynchos) eggs incubated under constant environmental conditions. Time required to reach the star-pipped stage of hatch varied significantly among females, but not with laying sequence or egg size. Metabolic rate of eggs varied positively with position in the laying sequence and tended to vary among females. Metabolic rate did not vary with egg volume or incubation length. Our results indicate metabolic rate may act as one synchronization mechanism for hatch. The role of maternal effects in development time should be considered in subsequent studies of incubation time in ducks.

Life history of the deep-sea cephalopod family Histioteuthidae in the western Mediterranean

NASA Astrophysics Data System (ADS)

Quetglas, Antoni; de Mesa, Aina; Ordines, Francesc; Grau, Amàlia

2010-08-01

The life cycle of the two species of the deep-sea family Histioteuthidae inhabiting the Mediterranean Sea ( Histioteuthis reversa and Histioteuthis bonnellii) was studied from monthly samples taken throughout the year during daytime hours by bottom trawl gears. A small sample of individuals found floating dead on the sea surface was also analyzed. Both species were caught exclusively on the upper slope at depths greater than 300 m. Their frequency of occurrence increased with depth and showed two different peaks, at 500-600 m and 600-700 m depth in H. bonnellii and H. reversa, respectively, which might indicate spatial segregation. Maturity stages were assigned using macroscopic determination and confirmed with histological analyses. Although mature males were caught all year round, no mature females were found, which suggests that their sexual maturation in the western Mediterranean takes place deeper than the maximum depth sampled (800 m). In fact, the increase in mean squid size with increasing depth in H. reversa indicates an ontogenetic migration to deeper waters. The individuals of both species found floating dead on the sea surface were spent females which had a relatively large cluster of small atresic eggs and a small number of remaining mature eggs scattered in the ovary and mantle cavity. The sizes of these females were clearly larger than the largest individuals caught with bottom trawls. A total of 12 and 7 different types of prey, belonging to three major taxonomic groups (crustaceans, osteichthyes and cephalopods), were identified in the stomach contents of H. reversa and H. bonnellii, respectively. In both species fishes were by far the main prey followed by crustaceans, whereas cephalopods were found only occasionally. The preys identified, mainly myctophids and natantian crustaceans, indicate that both histioteuthids base their diet on pelagic nictemeral migrators.

Life-history evolution when Lestes damselflies invaded vernal ponds.

PubMed

De Block, Marjan; McPeek, Mark A; Stoks, Robby

2008-02-01

We know little about the macroevolution of life-history traits along environmental gradients, especially with regard to the directionality compared to the ancestral states and the associated costs to other functions. Here we examine how age and size at maturity evolved when Lestes damselflies shifted from their ancestral temporary pond habitat (i.e., ponds that may dry once every decade or so) to extremely ephemeral vernal ponds (ponds that routinely dry completely each year). Larvae of three species were reared from eggs until emergence under different levels of photoperiod and transient starvation stress. Compared to the two temporary-pond Lestes, the phylogenetically derived vernal-pond Lestes dryas developed more rapidly across photoperiod treatments until the final instar, and only expressed plasticity in development time in the final instar under photoperiod levels that simulated a later hatching date. The documented change in development rate can be considered adaptive and underlies the success of the derived species in vernal ponds. Results suggest associated costs of faster development are lower mass at maturity and lower immune function after transient starvation stress. These costs may not only have impeded further evolution of the routine development rate to what is physiologically maximal, but also maintained some degree of plasticity to time constraints when the habitat shift occurred.

Effects of different storage time on hatching results and some egg quality characteristics of rock partridge (A. graeca) (management and production).

PubMed

Günhan, S; Kirikçi, K

2017-06-01

In this research, partridge eggs were stored during zero to 7, 8 to 14, 15 to 21, 22 to 28, 29 to 35 and 36 to 42 d, respectively. The effect of different egg storage periods on egg protein and moisture rates, mineral contents, and some egg quality and hatching characteristics were investigated. The extension of egg storage times didn't affect the external quality features like shell weight, shell thickness, and albumen rate, but it affected the yolk weight, yolk index, albumen index, and Haugh unit (P < 0.05). Yolk weight was increased and yolk index, albumen index, and Haugh unit values were decreased with the extension of storage time. Different storage times of partridge eggs did not have important effects on the protein rates. Protein and humidity rate of the eggs were 14.21 and 67.64%, respectively. There were some elements such as S, P, Na, K, and Ca, but Al, Cd, Co, Mo, and Pb could not be found in the partridge eggs. There is no effect of the storage time on the mineral content of the egg. Storage time had negative effect on fertility and hatchability after 21 d of storage d, but no effect on hatchability of fertile eggs. As this study showed, partridge eggs are resistant to long storage times, as partridge egg proteins can resist degradation in the optimum storage times. To determine egg degradation, the study should be focused on partridge eggshell features, which are responsible for degradation. As a result of this research, partridge eggs can be stored for 21 d under optimum storage conditions without any negative hatchability results. © 2017 Poultry Science Association Inc.

Infection rates of Enterobius vermicularis and Clonorchis sinensis of primary school children in Hamyang-gun, Gyeongsangnam-do (Province), Korea

PubMed Central

Kim, Bong Jin; Yeon, Je Wook

2001-01-01

The egg positive rate of Enterobius vermicularis and Clonorchis sinensis of school children in the rural area was studied in Hamyang-gun. Gyeongsangnam-do in Korea. Cellotape anal swab and formalin ether concentration methods were performed one time to 720 primary school children. The total egg positive rate of E. vermicularis was 12.6% in two schools (Baekjeon and Wiseong). In the Baekjeon and Wiseong primary school, the egg positive rate of E. vermicularis was 4.6% and 13.4%, respectively. Pinworm egg positive rate was 17.6% in the lower grades (1st. 2nd and 3rd), and 7.7% in higher grades (4th, 5th and 6th). The total egg positive rate of male and female was 12.6% and 12.7%, respectively. The egg positive rate of C. sinensis of Baekjeon and Wiseong primary school was 1.5% and 0.46%, respectively. The total egg positive rate of C. sinensis was 0.56%. This survey showed that continuous education and chemotherapy is necessary to treat and prevent reinfection of E. vermicularis. In the case of C. sinensis, health education for school children is recommended to prevent potential infection of adolescents. PMID:11775334

Modeling Honey Bee Populations.

PubMed

Torres, David J; Ricoy, Ulises M; Roybal, Shanae

2015-01-01

Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population.

Modeling Honey Bee Populations

PubMed Central

Torres, David J.; Ricoy, Ulises M.; Roybal, Shanae

2015-01-01

Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population. PMID:26148010

IVF versus ICSI for the fertilization of in-vitro matured human oocytes.

PubMed

Walls, M; Junk, S; Ryan, J P; Hart, R

2012-12-01

Traditional dogma suggests that intracytoplasmic sperm injection (ICSI) should be performed to ensure successful oocyte fertilization in an in-vitro maturation (IVM) cycle. This study postulated that there would be no difference in the fertilization rate when ICSI was compared with IVF. This hypothesis was tested in a randomized trial of IVF versus ICSI in IVM. A total of 150 immature oocytes were collected in eight cycles of IVM for patients diagnosed with polycystic ovarian syndrome (PCOS). Patients were primed with minimal FSH before transvaginal oocyte aspiration. Sibling oocytes were inseminated by 50% IVF and 50% ICSI. There was no significant difference in fertilization, useable or total blastocyst development between the two insemination technique groups. Clinical pregnancy results for combined fresh and cryopreserved transfers were identical between the two insemination techniques with a total of two fresh and five cryopreserved IVF-inseminated embryos resulting in three clinical pregnancies (42.9%) and five fresh and two cryopreserved ICSI-derived embryos resulting in three clinical pregnancies (42.9%). This research has shown IVF to be a legitimate fertilization technique for IVM oocytes in PCOS patients and provides a greater awareness of the use of a fertilization method previously not utilized with IVM. In-vitro maturation (IVM) is an alternative treatment method to traditional IVF. Due to the minimal use of stimulating hormones in this treatment, IVM has a lower risk of ovarian hyperstimulation syndrome, it can be used for fertility preservation in cancer patients and it is more cost conservative. Early research into the effects of IVM showed a hardening effect on the membrane surrounding the egg (the zona pellucida). It was initially believed that, to overcome this hardening in order to allow the egg to be fertilized, spermatozoa would need to be injected into the egg using intracytoplasmic sperm injection. Due to recent advances in hormonal stimulation protocols (FSH priming) and culture conditions, we postulated that, for patients suffering from polycystic ovarian syndrome (PCOS), fertilization, embryo development and clinical pregnancy would not be superior in the injected oocytes compared with those inseminated by IVF. We found that by using the two insemination techniques on sibling oocytes from eight PCOS patients, there was no significant difference in fertilization, useable or total blastocyst development (day 5 or 6 embryos) and that clinical pregnancy results were identical. This research provides a greater awareness of a fertilization technique which is not normally utilized for IVM treatment, providing a less invasive, more cost-effective approach for the patient. Copyright © 2012 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Report of the Insect Development Group

NASA Technical Reports Server (NTRS)

Rockstein, M.

1985-01-01

Drosophila metanogaster was chosen as the insect species of choice, in regard to gravity response experiments involving normal reproduction and develop different strains. The specific gravity responses which might be affected by microgravity and are exhibited in normal reproduction and development include normal flight for courtship, mating and oviposition, tropisms for pupating or emergency of the adult, and crawling for gettering food by the larval instars at the organismic level. At the suborganismic elevel, it is believed that maturation of developing eggs in the virgin female and embryonic development of the developing egg could be affected by microgravity and warrant study.

Laying traits and underlying transcripts, expressed in the hypothalamus and pituitary gland, that were associated with egg production variability in chickens.

PubMed

Chen, Chih-Feng; Shiue, Yow-Ling; Yen, Cheng-Ju; Tang, Pin-Chi; Chang, Hui-Chiu; Lee, Yen-Pai

2007-12-01

The objective was to characterize the potential laying traits and underlying transcripts expressed in the hypothalamus and pituitary gland that were associated with egg production variability in five genetic stocks of chickens: two commercial lines, Red- (n=12) and Black-feather (n=14) Taiwan country chickens (TCCs); two selected lines of TCCs, B (high body weight/comb size; n=17) and L2 (high-egg production; n=14); and a commercial single comb White Leghorn (WL; n=17). Six laying traits, age at first egg, clutch length, pause length, oviposition lag within clutch, follicle rapid growth period, and rate of yolk accumulation were measured. The significance of differential values among five chicken stocks and correlation coefficients between laying traits and number of eggs to 50 weeks of age or laying rate after first egg, and the expression level of 33 transcripts were determined. Longer clutch length and shorter oviposition lag within clutch contributed to a higher number of eggs to 50 weeks of age or laying rate after first egg in L2 (P<0.05) and WL strains (P<0.05). However, their rate of yolk accumulation (P<0.05) and follicle rapid growth period (P<0.05) were different, indicating the accumulation of different alleles after long-term, independent selection. Across all five strains, numbers of eggs to 50 weeks of age were positive correlated with average clutch length (P<0.05) as well as the rate of yolk accumulation (P<0.05). Expressions of PLAG1, STMN2, PGDS, PARK7, ANP32A, PCDHA@, SCG2, BDH and SAR1A transcripts contributed to number of eggs to 50 weeks of age (P<0.05) or laying rate after first egg (P<0.05). Analysis of correlation coefficients indicated that PLAG1 additionally played roles in decreasing average pause length. Two transcripts, PRL and GARNL1, specifically contributed to number of eggs to 50 weeks of age or laying rate after first egg by reducing oviposition lag within clutch (P<0.05) and/or increasing average clutch length (P<0.05), respectively. Expression level of NCAM1, contributed to laying rate after first egg by association with a shorter oviposition lag within clutch (P<0.05). The current study attributed egg production phenotype in five strains into several laying traits; correlations between these traits and expression levels of underlying transcripts expressed in the hypothalamus and pituitary gland were also established.

Food Irradiation Research and Technology

USDA-ARS?s Scientific Manuscript database

Food Irradiation is a safe and effective U.S. Food and Drug Administration (FDA) approved process that can be used to disinfest or delay the maturation of fruits and vegetables, improve the microbiological safety of shellfish, eggs, raw meat and poultry, spices, and seeds used for sprouting. FDA ap...

Food irradiation research and technology

USDA-ARS?s Scientific Manuscript database

Food Irradiation is a safe and effective U.S. Food and Drug Administration (FDA) approved process that can be used to disinfest or delay the maturation of fruits and vegetables, improve the microbiological safety of shellfish, eggs, raw meat and poultry, spices, and seeds used for sprouting. FDA ap...

OPTIMIZATION OF A PRECISION-CUT TROUT LIVER TISSUE SLICE ASSAY AS A SCREEN FOR VITELLOGENIN INDUCTION: COMPARISON OF SLIDE INCUBATION TECHNIQUES

EPA Science Inventory

The egg-yolk precursor protein vitellogenin (VTG) is normally only produced in the liver of female rainbow trout (RBT) in response to increasing 17B-estradiol (E2) during sexual maturation. However, its...

N-hexane alters the maturation of oocytes and induces apoptosis in mice.

PubMed

Liu, Jin; Huang, Lei; Sun, Yan; Li, Yu Chen; Zhu, Jian Lin; Wang, Wen Xiang; Zhang, Wen Chang

2013-09-01

This study was aimed to determine the effects of n-hexane on the maturation of mouse oocytes. Cell culture was used to observe the maturation of mouse oocytes and CLSM was employed to determine their apoptosis. Germinal vesicle breakdown (GVBD) and extrusion of the first polar body in mouse oocytes were significantly inhibited by n-hexane. After fertilization, the number of eggs in the mouse was significantly reduced by n-hexane. Mitochondrial membrane potentials (ΔΨm) were altered in mouse oocytes that were leading to apoptosis of the oocytes. N-hexane might have affected the maturation of oocytes, causing alteration of ΔΨm and leading to apoptosis which maybe one of the most important mechanisms. Copyright © 2013 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Enterobius vermicularis egg positive rate of pre-school children in Chunchon, Korea (1999)

PubMed Central

Yoon, Hyung-Jun; Choi, Ye-Jong; Lee, Soo-Ung; Park, Hyun-Young; Yang, Yong-Sang

2000-01-01

Pre-school children were examined for the presence of Enterobius vermicularis egg by perianal swab method. We visited 67 nurseries and 25 kindergartens between January, 1999 and April, 1999 in Chunchon, Korea. Of the 4,711 children examined, 434 (9.2%) were found to be positive for E. vermicularis egg. The egg positive rates of boys and girls were 10.1% and 8.1%, respectively. The rates were 7.8% in kindergartens and 9.7% in nurseries. Positive rate of 50 institutions was less than 10%. Rate in 35 institutions was from 10% to less than 20%. Rate in 7 institutions was equal to or over 20%. Out of 1,113 children examined twice, 28 (2.5%) children were positive consecutively, 53 (4.8%) were positive with negative conversion, 47 (4.2%) were negative with positive conversion, and 985 (88.5%) were consecutively negative. It means that in the low endemic area of enterobiasis with around 10% positive rate, the two consecutive examinations may increase the egg detection rate of 4.2-4.8%. The small number of consecutive egg positive children also suggests that the worm burden of the positive children might be low. Since the egg positive rate of that age group in this City increased from 1.85% (1997), and 3.0% (1998), the more intensive regular control should be executed. PMID:11138323

Gonotrophic cycle and survivorship of Anopheles vestitipennis (Diptera: Culicidae) in two different ecological areas of southern Mexico.

PubMed

Arredondo-Jiménez, J I; Rodríguez, M H; Washino, R K

1998-11-01

The duration of the gonotrophic cycle and survivorship of Anopheles vestitipennis Dyar & Knab was estimated in 2 malarious areas of Chiapas, Mexico: the Lacandon Forest and the Pacific Ocean Coastal Plain. Blood-engorged females held in an outdoor cage required 2.75 d for egg maturation, and 3.75 d for the duration of the gonotrophic cycle. Duration of the gonotrophic cycle also was estimated by parous-nulliparous dynamics for 20 consecutive days and autocorrelation time-series analysis, and by mark-recapture techniques. These methods depicted differences between the Lacandon Forest (3-d cycle) and the Coastal Plain (2-3 d cycles). Daily survival rates were estimated vertically and were generally higher in the Lacandon Forest (0.68) than in the Coastal Plain (0.45-0.58). The probability of mosquitoes surviving the sporogonic cycle was 10-100 times greater in the Lacandon Forest. The pregravid rate was 8.2%, and 29.3% of females with primary follicles beyond Christophers' stage III had traces of red blood in the gut. The 1st statistic indicated that 8.2% of females required > 1 blood meal for initial egg development, the 2nd statistic indicated that 29.3% of females take > 1 blood meal during a gonotrophic cycle. In summary, the enhanced vectorial role of this species is explained partially by high longevity and multiple blood-feeding habits.

Dietary lufenuron reduces egg hatch and influences protein expression in the fruit fly Bactrocera latifrons (Hendel).

PubMed

Chang, Chiou Ling; Geib, Scott; Cho, Il Kyu; Li, Qing X; Stanley, David

2014-08-01

Lufenuron (LFN), a chitin synthase inhibitor, impacts the fertility of Ceratitis capitata, Bactrocera dorsalis, B. cucurbitae, and B. latifrons. We posed the hypothesis that LFN curtails egg hatch in the solanaceous fruit fly, B. latifrons. In this study, newly emerged virgin adults were sexed and fed for 12 days with varying concentrations of LFN-laced agar diets until sexual maturation. Eggs were collected from 12-d-old adults and the egg hatch was assessed. Egg hatch decreased in adults reared on LFN-treated diets. LFN-treated media did not influence fertility after one gender was reared on experimental and the other on control media before mating. Exposure to LFN-treated medium after mating led to reduced egg hatch. We infer that LFN is not a permanent sterilant, and reduced egg hatch depends on continuous exposure to dietary LFN after mating. Proteomic analysis identified two differentially expressed proteins, a pheromone binding protein and a chitin binding protein, between adults maintained on LFN-treated and control diets. Expression of two genes encoding chitin synthase 2, and chitin binding protein, was altered in adults exposed to dietary LFN. LFN treatments also led to increased expression of two odorant binding proteins one in females and one in males. We surmise these data support our hypothesis and provide insight into LFN actions. © 2014 Wiley Periodicals, Inc.

Long-term reproductive and behavioral toxicity of anthracene to fish in the presence of solar ultraviolet radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, A.T.; Oris, J.T.

1994-12-31

The long-term, low-level effects of anthracene in the presence of solar ultraviolet radiation (SUVR) were examined in the fathead minnow (Pimephales promelas). Adult fish exposed to anthracene exhibited reduced egg laying capacity, with altered oocyte maturation as a potential mechanism of action. Eggs and larvae maternally exposed to anthracene exhibited reduced hatching success and severe developmental abnormalities when incubated under SUVR. The combination of reduced egg output and developmental effects resulted in an inhibition in reproductive capacity in the range of 70--100%. Maternal transfer of anthracene to eggs was efficient; the BCF was 717 for maternally exposed eggs. However, anthracenemore » deputation from eggs after oviposition with only maternal PAH exposure was rapid; anthracene half-life from eggs equaled 1.3 days. Exposure to anthracene under SUVR altered locomotor activity patterns in fathead minnows by inducing hyperactivity or hypoactivity during the light or dark phases of the photoperiod, respectively. Altered activity patterns indicated potential effects of anthracene on the nervous system and/or pineal gland. These alterations disrupted normal activity patterns and reproductive behaviors, and thus have major implications on a fish`s ability to survive and reproduce. Anthracene, a model phototoxic PAH, has many potential sites of toxic action, and any organism exposed to such contaminants will be an considerable SUVR-enhanced risk in the environment.« less

Involvement of Mos-MEK-MAPK pathway in cytostatic factor (CSF) arrest in eggs of the parthenogenetic insect, Athalia rosae.

PubMed

Yamamoto, Daisuke S; Tachibana, Kazunori; Sumitani, Megumi; Lee, Jae Min; Hatakeyama, Masatsugu

2008-01-01

Extensive survey of meiotic metaphase II arrest during oocyte maturation in vertebrates revealed that the mitogen-activated protein kinase (MAPK) pathway regulated by the c-mos proto-oncogene product, Mos, has an essential role in cytostatic activity, termed cytostatic factor (CSF). In contrast, little is known in invertebrates in which meiotic arrest occurs in most cases at metaphase I (MI arrest). A parthenogenetic insect, the sawfly Athalia rosae, in which artificial egg activation is practicable, has advantages to investigate the mechanisms of MI arrest. Both the MAPK/extracellular signal-regulated protein kinase kinase (MEK) and MAPK were phosphorylated and maintained active in MI-arrested sawfly eggs, whereas they were dephosphorylated soon after egg activation. Treatment of MI-arrested eggs with U0126, an inhibitor of MEK, resulted in dephosphorylation of MAPK and MI arrest was resumed. The sawfly c-mos gene orthologue encoding a serine/threonine kinase was cloned and analyzed. It was expressed in nurse cells in the ovaries. To examine CSF activity of the sawfly Mos, synthesized glutathione S-transferase (GST)-fusion sawfly Mos protein was injected into MI-resumed eggs in which MEK and MAPK were dephosphorylated. Both MEK and MAPK were phosphorylated again upon injection. In these GST-fusion sawfly Mos-injected eggs subsequent mitotic (syncytial) divisions were blocked and embryonic development was ceased. These results demonstrated that the MEK-MAPK pathway was involved in maintaining CSF arrest in sawfly eggs and Mos functioned as its upstream regulatory molecule.

Oxygen uptake by embryos and ovigerous females of two intertidal crabs, Heterozius rotundifrons (Belliidae) and Cyclograpsus lavauxi (Grapsidae): scaling and the metabolic costs of reproduction.

PubMed

Taylor, H H; Leelapiyanart, N

2001-03-01

Heterozius rotundifrons and Cyclograpsus lavauxi are crabs of similar size, whose intertidal habitats overlap. They differ in the number and size of their eggs. A 2 g ovigerous H. rotundifrons incubates 675 large yolky eggs (mean single-egg mass 269 microg; egg clutch 9.15 % of mass of female crab; increasing to 435 microg and 13.4 % at hatching). The egg clutch of a 2 g C. lavauxi is larger (15.4 % of crab mass increasing to 18.9 % at hatching) and contains more numerous (28 000), smaller (10.9 microg increasing to 20.3 microg) eggs. The longer development time of the larger eggs (194 days versus 56 days at 15 degrees C) results from a delayed increase in metabolic rate (diapause) and not metabolic scaling. On the basis of the total mass of single eggs, the mass-specific metabolic rates of early embryonic stages of H. rotundifrons (0.72 micromol g(-1 )h(-1) for the blastula stage at 15 degrees C) and C. lavauxi (1.13 micromol g(-1 )h(-1)) were similar to those of the adult female crabs (0.70 micromol g(-1 )h(-1) for H. rotundifrons and 0.91 micromol g(-1 )h(-1) for C. lavauxi) and increased 13- and 10-fold, respectively, by the time of hatching. Thus, early embryonic metabolic rates were much lower than expected from their mass, but the metabolic rates of pre-hatching embryos were consistent with the allometry of juveniles and adults. Possible interpretations of this apparently anomalous scaling of embryonic metabolic rates are discussed. Mass-specific rates of oxygen consumption by ovigerous females (including the eggs) of both species were higher than for non-ovigerous crabs, in water and in air, and increased greatly during the development of the eggs. This difference was attributable mainly to the increasing metabolic rates of the attached embryos, but early ovigerous crabs (blastula stage) of both species also demonstrated a small elevation in metabolic rate by the crab itself, i.e. a metabolic cost of egg-bearing. In contrast, the elevation of the rate of oxygen consumption by late ovigerous females of C. lavauxi was less than predicted from the metabolic rate of eggs in a stirred respirometer. This suggests that, towards the end of development in C. lavauxi, the oxygen supply to the eggs in situ may be diffusion-limited by unstirred layers, an effect not observed for the larger eggs and more open egg clutch of H. rotundifrons. The cost of development, in terms of total oxygen consumption of single eggs, from extrusion to hatching, was 3.34 micromol O2 (approximately 1.5 J) for H. rotundifrons and 0.105 micromol O2 (approximately 0.05 J) for C. lavauxi. This 30-fold ratio approximates the ratios of their initial masses and yolk contents but represents only approximately one-third of the initial energy contents of the eggs.

Mortality of Eggs and Newly Hatched Larvae of Lobesia botrana (Lepidoptera: Tortricidae) Exposed to High Temperatures in the Laboratory.

PubMed

Kiaeian Moosavi, F; Cargnus, E; Pavan, F; Zandigiacomo, P

2017-06-01

The hypothesis that bunch-zone leaf removal reduces infestations of the European grapevine moth, Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae), by increasing egg and larval mortality owing to sunlight exposure was evaluated in the laboratory by subjecting different egg stages (white, red-eyes, and black-head) and newly hatched larvae to high temperatures. Based on temperatures recorded in a northern Italian vineyard on sun-exposed berries belonging to south-west facing bunches, eggs were subjected to constant temperatures of 40 °C and 37 °C for one or two periods of 3 or 6 h, and to 24-h temperature cycle with peak of 40 °C. Larvae were exposed to 24-h high-temperature cycles with peaks of 35, 37, and 40 °C. The results showed partial egg mortality at 40 °C, increasing with exposure hours and periods, and as eggs matured. Egg mortality was not affected by exposure to 37 °C. Larval survival already decreased significantly at 37 °C and was even lower at 40 °C. These laboratory data are in agreement with the hypothesis that temperatures reached by berries exposed to sunlight cause egg and larval mortality. Data on egg and larval susceptibility to high temperatures have also implications for species distribution and effects of climate change. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Different Temperature and Cooling Patterns at the Blunt and Sharp Egg Poles Reflect the Arrangement of Eggs in an Avian Clutch

PubMed Central

Šálek, Miroslav E.; Zárybnická, Markéta

2015-01-01

Incubation is an energetically demanding process during which birds apply heat to their eggs to ensure embryonic development. Parent behaviours such as egg turning and exchanging the outer and central eggs in the nest cup affect the amount of heat lost to the environment from individual eggs. Little is known, however, about whether and how egg surface temperature and cooling rates vary among the different areas of an egg and how the arrangement of eggs within the clutch influences heat loss. We performed laboratory (using Japanese quail eggs) and field (with northern lapwing eggs) experiments using infrared imaging to assess the temperature and cooling patterns of heated eggs and clutches. We found that (i) the sharp poles of individual quail eggs warmed to a higher egg surface temperature than did the blunt poles, resulting in faster cooling at the sharp poles compared to the blunt poles; (ii) both quail and lapwing clutches with the sharp poles oriented towards the clutch centre (arranged clutches) maintained higher temperatures over the central part of the clutch than occurred in those clutches where most of the sharp egg poles were oriented towards the exterior (scattered clutches); and (iii) the arranged clutches of both quail and lapwing showed slower cooling rates at both the inner and outer clutch positions than did the respective parts of scattered clutches. Our results demonstrate that egg surface temperature and cooling rates differ between the sharp and blunt poles of the egg and that the orientation of individual eggs within the nest cup can significantly affect cooling of the clutch as a whole. We suggest that birds can arrange their eggs within the nest cup to optimise thermoregulation of the clutch. PMID:25658846

Different temperature and cooling patterns at the blunt and sharp egg poles reflect the arrangement of eggs in an avian clutch.

PubMed

Šálek, Miroslav E; Zárybnická, Markéta

2015-01-01

Incubation is an energetically demanding process during which birds apply heat to their eggs to ensure embryonic development. Parent behaviours such as egg turning and exchanging the outer and central eggs in the nest cup affect the amount of heat lost to the environment from individual eggs. Little is known, however, about whether and how egg surface temperature and cooling rates vary among the different areas of an egg and how the arrangement of eggs within the clutch influences heat loss. We performed laboratory (using Japanese quail eggs) and field (with northern lapwing eggs) experiments using infrared imaging to assess the temperature and cooling patterns of heated eggs and clutches. We found that (i) the sharp poles of individual quail eggs warmed to a higher egg surface temperature than did the blunt poles, resulting in faster cooling at the sharp poles compared to the blunt poles; (ii) both quail and lapwing clutches with the sharp poles oriented towards the clutch centre (arranged clutches) maintained higher temperatures over the central part of the clutch than occurred in those clutches where most of the sharp egg poles were oriented towards the exterior (scattered clutches); and (iii) the arranged clutches of both quail and lapwing showed slower cooling rates at both the inner and outer clutch positions than did the respective parts of scattered clutches. Our results demonstrate that egg surface temperature and cooling rates differ between the sharp and blunt poles of the egg and that the orientation of individual eggs within the nest cup can significantly affect cooling of the clutch as a whole. We suggest that birds can arrange their eggs within the nest cup to optimise thermoregulation of the clutch.

Influence of ovarian muscle contraction and oocyte growth on egg chamber elongation in Drosophila.

PubMed

Andersen, Darcy; Horne-Badovinac, Sally

2016-04-15

Organs are formed from multiple cell types that make distinct contributions to their shape. The Drosophila egg chamber provides a tractable model to dissect such contributions during morphogenesis. Egg chambers consist of 16 germ cells (GCs) surrounded by a somatic epithelium. Initially spherical, these structures elongate as they mature. This morphogenesis is thought to occur through a 'molecular corset' mechanism, whereby structural elements within the epithelium become circumferentially organized perpendicular to the elongation axis and resist the expansive growth of the GCs to promote elongation. Whether this epithelial organization provides the hypothesized constraining force has been difficult to discern, however, and a role for GC growth has not been demonstrated. Here, we provide evidence for this mechanism by altering the contractile activity of the tubular muscle sheath that surrounds developing egg chambers. Muscle hypo-contraction indirectly reduces GC growth and shortens the egg, which demonstrates the necessity of GC growth for elongation. Conversely, muscle hyper-contraction enhances the elongation program. Although this is an abnormal function for this muscle, this observation suggests that a corset-like force from the egg chamber's exterior could promote its lengthening. These findings highlight how physical contributions from several cell types are integrated to shape an organ. © 2016. Published by The Company of Biologists Ltd.

Influence of ovarian muscle contraction and oocyte growth on egg chamber elongation in Drosophila

PubMed Central

Andersen, Darcy; Horne-Badovinac, Sally

2016-01-01

Organs are formed from multiple cell types that make distinct contributions to their shape. The Drosophila egg chamber provides a tractable model to dissect such contributions during morphogenesis. Egg chambers consist of 16 germ cells (GCs) surrounded by a somatic epithelium. Initially spherical, these structures elongate as they mature. This morphogenesis is thought to occur through a ‘molecular corset’ mechanism, whereby structural elements within the epithelium become circumferentially organized perpendicular to the elongation axis and resist the expansive growth of the GCs to promote elongation. Whether this epithelial organization provides the hypothesized constraining force has been difficult to discern, however, and a role for GC growth has not been demonstrated. Here, we provide evidence for this mechanism by altering the contractile activity of the tubular muscle sheath that surrounds developing egg chambers. Muscle hypo-contraction indirectly reduces GC growth and shortens the egg, which demonstrates the necessity of GC growth for elongation. Conversely, muscle hyper-contraction enhances the elongation program. Although this is an abnormal function for this muscle, this observation suggests that a corset-like force from the egg chamber's exterior could promote its lengthening. These findings highlight how physical contributions from several cell types are integrated to shape an organ. PMID:26952985

Oviposition and Sex Ratio of the Redbanded Stink Bug, Piezodorous guildinii, in Soybean.

PubMed

Temple, Joshua H; Davis, Jeffrey A; Hardke, Jarrod T; Price, Paul P; Leonard, B Rogers

2016-06-17

Redbanded stink bug, Piezodorus guildinii (Westwood), is a significant soybean pest across the mid-south region of the United States. The objectives of these studies were to characterize: (1) redbanded stink bug oviposition in relationship to soybean maturity group (MG), plant structure, crop phenology, and vertical distribution within the plant canopy; and (2) redbanded stink bug adult sex ratios in relationship to soybean phenology. A total of 5645 redbanded stink bug eggs in 421 egg masses (clusters) were field collected from naturally-occurring populations in MG IV and V soybean over a three year period (2009 to 2011). The mean number of eggs within a cluster was 16.6 ± 0.3. Plant structures by MG interactions were highly significant with more egg masses oviposited on leaves in MG IV (79.4%) and more on pods in MG V (72.7%). The ratio of females to males was similar in all soybean growth stages except R5, where the sex ratio increased to 1.4:1, coinciding with peak oviposition. Only 29.9% of egg clusters in MG IV and 18.3% of egg clusters in MG V were oviposited in the upper 35 cm of the soybean canopy. Based on these results, sampling strategies and insecticide application placement for stink bugs may require modification.

Oviposition and Sex Ratio of the Redbanded Stink Bug, Piezodorous guildinii, in Soybean

PubMed Central

Temple, Joshua H.; Davis, Jeffrey A.; Hardke, Jarrod T.; Price, Paul P.; Leonard, B. Rogers

2016-01-01

Redbanded stink bug, Piezodorus guildinii (Westwood), is a significant soybean pest across the mid-south region of the United States. The objectives of these studies were to characterize: (1) redbanded stink bug oviposition in relationship to soybean maturity group (MG), plant structure, crop phenology, and vertical distribution within the plant canopy; and (2) redbanded stink bug adult sex ratios in relationship to soybean phenology. A total of 5645 redbanded stink bug eggs in 421 egg masses (clusters) were field collected from naturally-occurring populations in MG IV and V soybean over a three year period (2009 to 2011). The mean number of eggs within a cluster was 16.6 ± 0.3. Plant structures by MG interactions were highly significant with more egg masses oviposited on leaves in MG IV (79.4%) and more on pods in MG V (72.7%). The ratio of females to males was similar in all soybean growth stages except R5, where the sex ratio increased to 1.4:1, coinciding with peak oviposition. Only 29.9% of egg clusters in MG IV and 18.3% of egg clusters in MG V were oviposited in the upper 35 cm of the soybean canopy. Based on these results, sampling strategies and insecticide application placement for stink bugs may require modification. PMID:27322333

Behaviour of the vitelline envelope in Bufo arenarum oocytes matured in vitro in blockade to polyspermy.

PubMed

Oterino, J; Sánchez Toranzo, G; Zelarayán, L; Ajmat, M T; Bonilla, F; Bühler, M I

2006-05-01

During activation of amphibian eggs, cortical granule exocytosis causes elaborate ultrastructural changes in the vitelline envelope. These changes involve modifications in the structure of the vitelline envelope and formation of a fertilization envelope (FE) that can no longer be penetrated by sperm. In Bufo arenarum, as the egg traverses the oviduct, the vitelline envelope is altered by a trypsin-like protease secreted by the oviduct, which induces an increased susceptibility of the vitelline envelope to sperm lysins. Full-grown oocytes of B. arenarum, matured in vitro by progesterone, are polyspermic, although cortical granule exocytosis seems to occur within a normal chronological sequence. These oocytes can be fertilized with or without trypsin treatment, suggesting that the vitelline envelope is totally sperm-permeable. Vitelline envelopes without trypsin treatment cannot retain either gp90 or gp96. This suggests that these glycoproteins are involved in the block to polyspermy and that trypsin treatment of matured in vitro oocytes before insemination is necessary to enable vitelline envelopes to block polyspermy. The loss of the binding capacity in vitelline envelopes isolated from B. arenarum oocytes matured in vitro with trypsin treatment and activated by electric shock suggests that previous trypsin treatment is a necessary step for sperm block to occur. When in vitro matured oocytes were incubated with the product of cortical granules obtained from in vitro matured oocytes (vCGP), vitelline envelopes with trypsin treatment were able to block sperm entry. These oocytes exhibited the characteristic signs of activation. These results support the idea that B. arenarum oocytes can be activated by external stimuli and suggest the presence of unknown oocyte surface receptors linked to the activation machinery in response to fertilization. Electrophoretic profiles obtained by SDS-PAGE of solubilized vitelline envelopes from oocytes matured in vitro revealed the conversion of gp40 (in vitro matured oocytes, without trypsin treatment) to gp38 (ascribable to trypsin activity or cortical granule product activity, CGP) and the conversion of gp70 to gp68 (ascribable to trypsin activity plus CGP activity). Taking into account that only the vitelline envelopes of in vitro matured oocytes with trypsin treatment and activated can block sperm entry, we may suggest that the conversion of gp70 to gp68 is related to the changes associated with sperm binding.

Yolk proteins during ovary and egg development of mature female freshwater crayfish (Cherax quadricarinatus).

PubMed

Serrano-Pinto, Vania; Vazquez-Boucard, Celia; Villarreal-Colmenares, Humberto

2003-01-01

Vitellins from ovaries and eggs at different stages of development in freshwater crayfish (Cherax quadricarinatus) were examined by chromatography, PAGE and SDS-PAGE. With these methods, two forms of vitellin (Vt1 and Vt2) were observed in ovaries and eggs (stages I and V). In ovaries in secondary vitellogenesis, native molecular mass was 470 (Vt1) and 440 (Vt2) kDa. The electrophoretic pattern of the eggs proved to be more complex. The protein molecular mass depend on the development stage of the egg: stage I, 650 kDa (Vt1) and 440 kDa (Vt2); stage V, 390 kDa (Vt1) and 340 kDa (Vt2). The identified vitellins appear to be lipo-glycocarotenoprotein. A similar vitellin polypeptide composition was observed in the two forms of vitellin from ovaries and eggs in stage V. In ovaries the SDS-PAGE analysis showed four subunits with molecular weights of approximately 180, 120, 95 and 80 kDa (Vt1 and Vt2). The polypeptide composition in the two forms of vitellins in stage I and stage III eggs were different at 195, 190, 130 and 110 kDa (Vt1) and 116 and 107 kDa (Vt2). On the other hand, in stage V eggs, 110, 95, 87 and 75 kDa (Vt1 and Vt2) were identified. Two antibodies (Ab1 and Ab2) were prepared against the purified proteins of stage V eggs and their specificity was demonstrated by radial immunoprecipitation, and Western blotting analysis. Two forms of vitellins were also found in stage V eggs after chromatography on Sepharose CL-2B column and hydroxylapatite and polyacrylamide gel electrophoresis.

Caffeine alleviates the deterioration of Ca2+ release mechanisms and fragmentation of in vitro aged mouse eggs

PubMed Central

Zhang, Nan; Wakai, Takuya; Fissore, Rafael. A.

2011-01-01

The developmental competence of mammalian eggs is compromised by postovulatory aging. We and others found that in these eggs the intracellular calcium ([Ca2+]i) responses required for egg activation and initiation of development are altered. Nevertheless, the mechanism(s) underlying this defective Ca2+ release is not well known. Here, we investigated if the function of IP3R1, the major Ca2+ release channel at fertilization, was undermined in in vitro aged mouse eggs. We found that in aged eggs IP3R1 displayed reduced function, as many of the changes acquired during maturation that enhance IP3R1 Ca2+ conductivity such as phosphorylation, receptor reorganization and increased Ca2+ store content ([Ca2+]ER) were lost with increasing postovulatory time. IP3R1 fragmentation, possibly associated with the activation of caspase-3, was also observed in these eggs. Many of these changes were prevented when the postovulatory aging of eggs was carried out in the presence of caffeine, which minimized the decline in IP3R1 function and maintained [Ca2+]ER content. Caffeine also maintained mitochondrial membrane potential as measured by JC-1 fluorescence. We therefore conclude that [Ca2+]i responses in aged eggs are undermined by reduced IP3R1 sensitivity, decreased [Ca2+]ER and compromised mitochondrial function, and that addition of caffeine ameliorates most of these aging-associated changes. Understanding the molecular basis of the protective effects of caffeine will be useful in elucidating, and possibly reversing, the signaling pathway(s) compromised by in vitro culture of eggs. PMID:22095868

Ionizing Solutions to Future Processor Demands for Safe Food

USDA-ARS?s Scientific Manuscript database

Food Irradiation is a safe and effective U.S. Food and Drug Administration (FDA) approved process that can be used to disinfest or delay the maturation of fruits and vegetables, improve the microbiological safety of shellfish, eggs, raw meat and poultry, spices, and seeds used for sprouting. FDA ap...

Establishment of a medium-scale mosquito facility: tests on mass production cages for Aedes albopictus (Diptera: Culicidae).

PubMed

Zhang, Dongjing; Li, Yongjun; Sun, Qiang; Zheng, Xiaoying; Gilles, Jeremie R L; Yamada, Hanano; Wu, Zhongdao; Xi, Zhiyong; Wu, Yu

2018-03-19

Mass egg production is an important component of Aedes albopictus mosquito control programs, such as the sterile insect technique and incompatible insect technique, which requires the releases of large number of sterile males. Developing standard operating procedures and optimized cages for adult maintenance of Ae. albopictus can improve the mass rearing efficiency. Three different sex ratios of females to males with a total number of 4,000 mosquitoes were tested by evaluating the insemination rate, egg production (total number of eggs per cage), female fecundity and egg hatch rate in small cage (30 × 30 × 30 cm). Blood meals with adenosine triphosphate (ATP, 0.05 g/ml), cage structures (Big cage A: 90 × 30 × 30 cm; Big cage B: 90 × 30 × 50 cm or 90 × 50 × 30 cm) and rearing densities (12,000, 16,000 and 20,000 mosquitoes, corresponding to 0.9 cm 2 /mosquito, 0.675 cm 2 /mosquito and 0.54 cm 2 /mosquito, respectively) were also tested and evaluated on the basis of egg production, female fecundity and egg hatch rate. An adult rearing unit holding 15 of Big cage A with optimal egg production was designed to produce 10 million eggs per rearing cycle in a 1.8 m 2 space. Female to male ratios at 3:1 in small cages resulted in higher egg production but did not affect insemination rate, female fecundity and egg hatch rate. A concentration of 0.05 g/ml of ATP added to blood meals improved the blood-feeding frequency and thus increased the overall egg production per cage. Cage structures affected the egg production per cage, but not egg hatch rate. A medium rearing density at 0.675 cm 2 /mosquito (16,000 mosquitoes) resulted in higher egg production compared to both low and high densities. An adult rearing unit for Ae. albopictus on the basis of Big cage A has been developed with the capacity of producing 10 million eggs within 15 days. Our results have indicated that the adult rearing methods and adult maintenance unit are recommended for Ae. albopictus mass rearing in support of the establishment of a medium-sized mosquito factory.

Reproductive traits of shovelnose sturgeon Scaphirhynchus platorynchus (Rafinesque, 1820) in the lower Platte River, Nebraska

USGS Publications Warehouse

Hamel, M. J.; Rugg, M.L.; Pegg, M.A.; Patino, Reynaldo; Hammen, J.J.

2015-01-01

We assessed reproductive status, fecundity, egg size, and spawning dynamics of shovelnose sturgeon Scaphirhynchus platorynchus in the lower Platte River. Shovelnose sturgeon were captured throughout each year during 2011 and 2012 using a multi-gear approach designed to collect a variety of fish of varying sizes and ages. Fish were collected monthly for a laboratory assessment of reproductive condition. Female shovelnose sturgeon reached fork length at 50% maturity (FL50) at 547 mm and at a minimum length of 449 mm. The average female spawning cycle was 3–5 years. Mean egg count for adult females was 16 098 ± 1103 (SE), and mean egg size was 2.401 ± 0.051 (SE) mm. Total fecundity was positively correlated with length (r2 = 0.728; P < 0.001), mass (r2 = 0.896; P < 0.001), and age (r2 = 0.396; P = 0.029). However, fish size and age did not correlate to egg size (P > 0.05). Male shovelnose sturgeon reached FL50 at 579 mm and at a minimum length of 453 mm. The average male spawning cycle was 1–2 years. Reproductively viable male and female sturgeon occurred during the spring (March–May) and autumn (September–October) in both years, indicating spring and potential autumn spawning events. Shovelnose sturgeon in the lower Platte River are maturing at a shorter length and younger age compared to populations elsewhere. Although it is unknown if the change is plastic or evolutionary, unfavorable environmental conditions or over-harvest may lead to hastened declines compared to other systems.

Hatchery production of the clownfish Amphiprion nigripes at Agatti Island, Lakshadweep, India.

PubMed

Kumar, T T Ajith; Gopi, M; Dhaneesh, K V; Vinoth, R; Ghosh, S; Balasubramanian, T; Shunmugaraj, T

2012-05-01

Healthy individuals of matured clownfish, Amphiprion nigripes and sea anemone, Heteractis magnifica were collected from the Agatti island lagoon by snorkeling. During 'conditioning' for 3 months, pair formation occurred and the same were transferred to rectangular fiber glass spawning tanks of 10001 capacity. Suitable water quality parameters were maintained. The fishes were fed with tuna eggs, boiled clam meat, squid, octopus and trash fish thrice in a day. Reproductive behaviour and embryonic development were documented. Spawning took place in between 0900 - 1100 hr and hatched-out occurs, after sunset following an incubation period of 8-9 days. Size of the newly laid egg was 2.0-2.2 mm in length and 1.0-1.2 mm in width. The larval rearing tanks were maintained with UV-treated water and followed the optimal physico-chemical parameters as in the parent tanks. The different light regimes and diets were used for the successful larval rearing. The maximum larval survival (61%) was achieved at the photoperiod of 24 L/0D. Within 15-17 days, the larvae metamorphosed and took up parent colouration and comparatively high growth rate was observed when fed on algae enriched rotifer than those with poly unsaturated fatty acid (PUFA).

Development of Alouattamyia baeri (Diptera: Oestridae) from howler monkeys (Primates: Cebidae) on Barro Colorado Island, Panama.

PubMed

Colwell, D D; Milton, K

1998-09-01

The fecundity and development of larval stages of the cuterebrid bot fly A. baeri were studied in an unusual host, remotely related to the primary host. Third-instar Alouattamyia baeri (Shannon & Greene) removed from howler monkeys, Alouatta palliata, were allowed to pupate and then were cultured under controlled conditions. Eclosion occurred after 37.9 +/- 0.4 (mean +/- SE) (male) and 38.2 +/- 0.4 (female) d at 26 degrees C. Five-day-old females were mated using a tethered flight technique and oviposited on ridged filter paper. The total egg complement was 1,399 +/- 243 (n = 2) eggs per female. Eggs were fully embryonated after incubation for 5 d at 26 degrees C. Eggs hatched when warmed in the palm of the hand. Hatching of eggs from an individual batch was asynchronous. Newly hatched larvae would not penetrate intact skin on a rabbit, Oryctolagus cuniculus L. Larvae placed near the nares or on the ocular conjunctiva migrated rapidly from view. Warbles containing larvae were first observed on infested rabbits 5 d after infestation. Development of larvae proceeded until day 39 after infestation, when nearly mature 3rd instars were observed. None of the larvae survived to pupate.

Aspects of the reproductive ecology of female turtles in New Mexico

USGS Publications Warehouse

Lovich, Jeffrey E.; Agha, Mickey; Painter, Charlie; Cole, Levi; Fitzgerald, Austin; Narum, Kevin; Jennings, Randy

2016-01-01

Data on reproductive ecology of turtles in New Mexico are limited, and some species living there are among the least studied in the United States. We trapped 4 native species of turtles (Apalone spinifera, Chrysemys picta, Pseudemys gorzugi, and Trachemys gaigeae gaigeae) in the Rio Grande and Black River (Pecos River drainage) of New Mexico in June 2012 and 2013 to collect data on female reproductive ecology, including clutch size, egg size, timing of egg production, and percentage of gravid females. During our sampling, we found shelled eggs via X-radiography in only 3 native species: C. picta, P. gorzugi, and T. g. gaigeae. Clutch and egg sizes were within the range of previously reported values, although clutch size for P. gorzugi (10 eggs) is only the second published record for that data-deficient species. Clutch size increased with body size in T. g. gaigeae. We observed few differences between reproductive parameters for turtles in New Mexico and their conspecifics and congeners elsewhere in the United States, other than the observation that female C. picta may mature at smaller body sizes in New Mexico relative to other western populations elsewhere in its vast, primarily eastern North American range.

Reproductive biology of the two deep-sea chimaerids, longnose spookfish (Harriotta raleighana) and Pacific spookfish (Rhinochimaera pacifica)

NASA Astrophysics Data System (ADS)

Finucci, B.; Dunn, M. R.; Jones, E. G.; Anderson, J.

2017-02-01

The family Rhinochimaeridae, the long-nose chimaerids, consists of eight species across three genera, two of which occur in New Zealand waters. Very little is known about the biology of the rhinochimaerids. Longnose spookfish, (Harriotta raleighana, Goode and Bean, 1895), and Pacific spookfish, (Rhinochimaera pacifica,Mitsukuri, 1895), were collected from research trawl surveys and by commercial fishing vessels around New Zealand at depths between 400 and 1300 m. A total of 300 H. raleighana were caught which varied in length from 18.7 to 90.4 cm chimaera length (CL), and 168 R. pacifica at lengths of 20.9-139.9 cm CL. External assessment of male claspers and female gonad mass and oviducal gland width were the best indicators for maturity. Both species matured at a large proportion of their maximum length. Length at maturity was estimated at 62.8 cm CL and 75.8 cm CL for male and female H. raleighana respectively, and 105.3 cm CL and 125.0 cm CL for male and female R. pacifica. Fecundity was low and measured up to 27 eggs for H. raleighana, and 31 eggs for R. pacifica. Sperm storage was confirmed in females of both species. Sexual dimorphism in snout length was found in H. raleighana, where male relative snout size increased at sexual maturity, suggesting the snout is a secondary sexual characteristic. This study contributes to a better understanding of the life histories of H. raleighana and R. pacifica and their vulnerability to exploitation as fisheries bycatch.

Effect of storage duration on the rheological properties of goose liquid egg products and eggshell membranes.

PubMed

Kumbar, V; Nedomova, S; Trnka, J; Buchar, J; Pytel, R

2016-07-01

In practice, goose eggs are increasingly used and, therefore, the rheological properties have to be known for processing. The eggs of geese (Landes Goose, Anser anser f. domestica) were stored for one, 2, 3, 4, 6, and 8 wk at a constant temperature 4°C. First of all, the egg quality parameters were described in terms of egg weight, egg weight loss, egg shape index, yolk height, albumen height, yolk index, albumen index, and Haugh units. In the next step the rheological behavior of liquid egg products (egg yolk, albumen, and whole liquid egg) was studied using a concentric cylinder viscometer. Flow curves of all liquid egg products exhibited non-Newtonian shear thinning behavior. This behavior can be described using the Herschel-Bulkley model and for technical application using the Ostwald-de Waele model. The effect of the storage duration on the rheological behavior is different for the different liquid egg products. With the exception of very low shear rates, the viscosity of the egg yolk as well as of the whole liquid egg decreases with storage time. At lower shear rates there is a tendency toward increased albumen viscosity with storage duration. The storage duration also affects the mechanical properties of the eggshell membrane. This effect has been evaluated in terms of the ultimate tensile strength, fracture strain, and fracture toughness. All these parameters increased with the loading rate, but decreased during the egg storage. These mechanical phenomena should be respected, namely in the design of the egg model for the numerical simulation of the egg behavior under different kinds of the mechanical loading. © 2016 Poultry Science Association Inc.

The case for a cause-effect linkage between environmental contamination and development in eggs of the common snapping turtle (Chelydra S. serpentina) from Ontario, Canada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bishop, C.A.; Brooks, R.J.; Carey, J.H.

1991-08-01

Concentrations of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins, and dibenzofurans, organochlorine pesticides, and their metabolites were measured in eggs of the common snapping turtle (Chelydra s.serpentina) collected from four wetlands on the shorelines of Lakes Ontario, and Erie, and one control location in central Ontario, Canada. Snapping turtle eggs from these sites were also artificially incubated to determine hatching success, and incidence of deformities in embryo and hatchling turtles. The hypothesis that elevated incidences of egg death and/or deformities of hatchling turtles would occur in populations with high concentrations of organochlorine contaminants in eggs was tested. The results were elevated using epidemiologicalmore » criteria. Unhatched eggs and deformities occurred at significantly higher rates in eggs from Lake Ontario wetlands. Two of three sites from Lake Ontario had substantially higher levels of PCBs, dioxins, and furans compared to eggs from Lake Erie and the control site. It could not be shown that contamination of eggs preceded the occurrence of poor development of eggs, although excellent hatching success and low numbers of deformities in eggs from the control site were considered representative of development in healthy eggs. The statistical association between contaminant levels in eggs and poor development of these eggs supported the hypothesis that eggs from sites with the greatest contamination had the highest rates of abnormalities. PCBs were the most strongly associated chemicals, although possible effects due to the presence of other chemicals in eggs was a confounding factor. The deformities and rates of unhatched eggs were similar to those occurring in other vertebrates collected from highly contaminated areas of the Great Lakes. 54 references.« less

Egg Hatch Rate and Nymphal Survival of the Bed Bug (Hemiptera: Cimicidae) After Exposure to Insecticide Sprays.

PubMed

Hinson, K R; Benson, E P; Zungoli, P A; Bridges, W C; Ellis, B R

2016-12-01

Few studies have addressed the efficacy of insecticides used against eggs and first-instar nymphs of the bed bug, Cimex lectularius L. (Hemiptera: Cimicidae). Insect eggs are often resistant to insecticides; therefore, information on which products are effective is important. We evaluated the efficacy of four commonly used insecticide sprays applied directly to bed bug eggs. We also evaluated the efficacy of these insecticides to first-instar nymphs exposed to residuals resulting from directly spraying eggs. Temprid SC (beta-cyfluthrin, imidacloprid) was the most effective insecticide at preventing egg hatch (13% hatch rate) for pyrethroid-resistant, field-strain (Jersey City) bed bugs compared with a control (water [99% hatch rate]), Bedlam (MGK-264, sumithrin [84% hatch rate]), Demand CS (lambda-cyhalothrin [91% hatch rate]), and Phantom SC (chlorfenapyr [95% hatch rate]). Demand CS and Temprid SC were most effective at preventing egg hatch (0%) for an insecticide-susceptible (Harold Harlan) strain, followed by Bedlam (28%). Phantom SC produced a hatch rate similar to the control (97% and 96%, respectively). Harold Harlan-strain nymphs showed 100% survival for the control but 0% survival for Bedlam and Phantom SC. Jersey City-strain nymphs showed 100% survival for the control, 99% survival for Bedlam, 0% survival for Demand CS, 4% survival for Phantom SC, and 38% survival for Temprid SC. Demand CS was less effective at preventing hatch (91% hatch rate) of Jersey City-strain nymphs but was the only product to kill all nymphs (0% survival). One of the least effective products for preventing Jersey City-strain egg hatch (Phantom SC, 95% hatch rate) was the second most effective at killing nymphs, leaving only six of 141 alive. These findings indicate that survival of directly sprayed eggs and residually exposed, first-instar nymphs varies by strain, life stage, and product used. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Comparison between old and new methods for detection of allergenic substances (egg and milk)].

PubMed

Watanabe, Hiroko; Akaboshi, Chie; Saita, Kiyotaka; Sekido, Haruko; Hashiguchi, Shigeki; Watabe, Kenjiro; Tanaka, Kouki

2011-01-01

The old ELISA method for detection of allergenic substances (egg and milk) in Kanagawa prefecture from 2003 to 2007, employed before improvement of the food allergen labeling system, yielded detection rates of 20% for egg and 30% for milk. In 2005, after improvement of the labeling system, the detection rate using the new ELISA in solutions containing 1% SDS and 7% 2-mercaptoethanol increased by about 10% for egg, but decreased by half for milk. There were 4 positive samples (over 10 µg/g) for both egg and milk proteins, on account of contamination by ingredients at the manufacturing line and the lack of proper food labeling. In 2009, the contamination levels of egg and milk proteins in labeled commercial foods were low. In a comparison between the new and old methods with the same samples, both the new ELISA and Western-blot analyses showed an increase in the detection rate of egg protein. In relation to milk protein, the detection rates were decreased with the new ELISA, although the ELISA detection rate and consistency rates with Western-blot analysis were increased. On the other hand, in the case of a protein content below 5 µg/g, it was impossible to determine ovomucoid and casein by Western-blot analysis.

Selection and characterisation of monepantel resistance in Teladorsagia circumcincta isolates.

PubMed

Bartley, D J; Devin, L; Nath, M; Morrison, A A

2015-08-01

Monepantel (MPTL) is one of two new anthelmintic compounds introduced onto the sheep market to control gastro-intestinal nematodes. Resistance to this compound is rare but has been reported. In order to preserve the efficacy of this and other anthelmintics, it is essential to understand both (a) the mechanisms involved in the selection of resistance and (b) how the parasites evolve to deal with these compounds. To address these questions three MPTL-resistant Teladorsagia circumcincta isolates (MTci2-11, MTci5-13 and MTci7-12) have been artificially selected in vivo from phenotypically characterised parent isolates (MTci2, MTci5, MTci7 respectively). The selection process involved collecting and culturing eggs from surviving worms from sheep administered sub-optimal dosages of MPTL (Zolvix®) to provide infective larvae to infect further sheep until resistant isolates were generated (between 9 and 13 rounds of selection). A controlled efficacy test was conducted using the original parental isolates and the newly generated MPTL resistant isolates (n = 5 per group). Selected isolates were assessed both under anthelmintic stress (Zolvix®, 2.5 mg/kg bodyweight; MTci-MPTL) and at rest (untreated, MTci-CON). A number of life-history traits were assessed, namely, worm establishment rates, time to patency, faecal egg output, body length of adults and eggs in utero. The estimated resistance status of the selected isolates was confirmed with 48%, 28% and 9% reductions in worm burden at 7-days post Zolvix® administration for MTci2-11-MPTL, MTci5-13-MPTL and MTci7-12-MPTL, respectively, compared with untreated controls. One of the selected isolates MTci7-12-CON showed significantly greater total worm burden (p = 0.025), greater establishment rate (p = 0.033), decreased time to patency (p = 0.048), higher cumulative egg outputs (p = 0.002) compared with its parental derivative MTci7. The trial results suggest that anthelmintic selection in T. circumcincta, albeit under experimental conditions, can select for more prolific/fecund and quicker maturing populations. These data provide an insight into how parasites evolve in response to anthelmintic pressure.

Field Acceptance and Nutritional Intake of the Meal, Ready-to-Eat and Heat and Serve Ration.

DTIC Science & Technology

1998-05-01

Scrambled Eggs (Natick) and Scrambled Eggs w/Bacon(Natick). These two mean ratings were received from the control group. Table 4A Control Group H&S...6.4 Creamed Ground Beef 6.3 Corned Beef Hash 6.1 Western Scrambled Eggs (Natick)* 4.6 Scrambled Eggs w...5.4 20 38 33 * Natick - NRDEC developed eggs Table 4B Test Group H&S Breakfast Acceptability Ratings (n=39) Food Groups Food Item Entrees

[Experimental and epidemiological studies on the life cycle of Echinostoma hortense Asada, 1926 (Trematoda: Echinostomatidae)

PubMed

Ahn, Yung Kyum; Ryang, Yong Suk

1986-12-01

Recently there have been some reports on human infections of Echinostoma hortense in Korea. It was found that a few species of freshwater fishes were playing the role of the second intermediate host of E. hortense. However, molluscan intermediate host has not been identified yet in Korea. The present study aimed to establish the life cycle of E. hortense in laboratory. Experimental studies such as egg production from the rat, development of the eggs in vitro, exposure of miracidia to freshwater snails, shedding pattern of cercariae from infected snails, morphology of cercariae, cercarial infection to the second intermediate host and infection of metacercariae to the difinitive hosts were done. In addition, epidemiological surveys on the infection status in inhabitants and house rats, and on the natural infection of larval echinostomes in the snails and fishes were carried out along the South Hangang-river. The results obtained were as follows: The eggs deposited from adults in physiological saline were cultivated at room temperature (20-24C). The miracidia were firstly observed on 8 days after cultivation, and 85.5 per cent of the eggs contained the mature miracidia on 11 days after cultivation. More than 90 per cent formed the miracidia when cultivated at temperature 22-27C. Hatching of the miracidia began on 12 days after cultivation and continued for a week. The size of the miracidia was 103.0 x 51.4 micrometer in average. The motility of miracidia were active up to 8 hours after shedding, but they were all dead within 10 hours after shedding. A freshwater snail, Radix auricularia coreana was cultivated in aquaria. A hatched F1 snails from the egg masses were exposed to 20 miracidia respectively. Escape of cercariae started on 15 days after infection. Radix auricularia coreana was experimentally identified as the first intermediate host of E. hortense in Korea. Cercarial shedding started on 15-20 days after infection by snail, continued for about 10 days (8.8 days in average). Infected snails were dead within 32 days after the miracidial infection. About 1,335 cercariae (328-1,994) per snail were shed in its life, and 119 cercariae in average per snail per day were shed. The cercariae were motile for more than 24 hours, and then squirming at the bottom until death. The body and tail sizes of cercariae were 356 x 186 micrometer and 510 x 68 micrometer in average, respectively. The rediae parasitized in the snail hosts were found mainly around the pericardial regions, and their size was 1,575 x 258 micrometer in average. The numbers of developing cercariae in a mature redia were 14 in average (7-20 in range). The numbers of rediae in a snail were 102 in average on 15 days after miracidial infection and 221 in average on 28 days. Three uninfected Misgurnus anguillicaudatus, less than 6.5 cm long were used in for the cercaria1 infection. They were all exposed with 755 cercariae, and examined at 5-day intervals starting from 10 days after infection. All the fihes were infected with metacercariae of E. hortense and a total of 275 was found infected (36.4 per cent). The metacercariae were fed to rats and the adult worms were obtained on 15 days after infection. The infected rats began to deposit the eggs on 11 days after infection. The number of eggs deposited per day per worm (EPD/worm) was 400-500 on 3 weeks after infection and was increased to 1,000-1,500 on 4 to 17 weeks, then decreased to 800 on 2l weeks after infection. A total of 745 stool specimens collected from 576 male and 169 female residents of 8 different villages along South Hangang basin was examined. Out of 745 specimens, the eggs of Echinostoma sp. were found in 2 cases (0.3 per cent). Of 34 house rats one showed egg-positive (2.9 per cent). Total 971 Radix auricularia coreana collected from 7 sampling stations were examined for shedding of cercariae. Three snails (0.3 per cent) shed the cercariae of E. hortense. A total of 119 out of 542 freshwater fishes (22.0 per cent) had the metacercariae of E. hortense. The fishes parasitized with the metacercariae were 4 out of 14 examined species. The infection rate of 4 species were 34.1 per cent (106 out of 311) in Misgurnus anguillicaudatus, 30.4 per cent 7 out of 23) in Misgurnus mizolepis, 4.3 per cent (2 out of 46) in Moroco oxycephalus and 22.2 per cent (4 out of 18) in Odontobutis obscura interrupta. In summarizing the above results, the first intermediate host of E. hortense was found as Radix auricularia coreana in Korea. Also it took about 46 days for the shortest completion of a life cycle of E. hortense in summer; that is, 10 days for miracidial development in eggs, 15 days for cercarial development in the snail, about 10 days for metacercarial development in the second intermediate hosts, 11 days for the maturation as the adults in the definitive hosts. The natural infection rates of E. hortense in the intermediate hosts were relatively high but those in the definitive hosts were low in the middle areas of South Hangang basin.

Status of intestinal helminthic infections of borderline residents in North Korea.

PubMed

Li, Shunyu; Shen, Chenghua; Choi, Min-Ho; Bae, Young Mee; Yoon, Hiwon; Hong, Sung-Tae

2006-09-01

The present authors investigated intestinal parasitic infections among North Korean residents and refugees in China in 2003. The Kato-Katz method was applied to 236 residents and soldiers in a town on the North Korea-China border and to 46 people at a refugee camp in China. Only eggs of Ascaris and Trichuris were detected, with egg positive rates of 41.1% and 37.6%, respectively. The total egg positive rate was 55.0% and most of those who were egg positive were only lightly infected. Women of 61.2% and men of 53.1% were egg positive. The refugees from rural areas showed higher egg positive rates than those from urban areas. The present investigation confirmed high prevalence of soil-transmitted intestinal helminths in rural borderline areas of North Korea.

Predictions of realised fecundity and spawning time in Norwegian spring-spawning herring ( Clupea harengus)

NASA Astrophysics Data System (ADS)

Óskarsson, G. J.; Kjesbu, O. S.; Slotte, A.

2002-08-01

Maturing Norwegian spring-spawning (NSS) herring, Clupea harengus, were collected for reproductive analyses along the Norwegian coast prior to the spawning seasons of 1997-2000. Over this time period there was a marked change in weight (W) at length (TL) with 1998 showing extremely low values and 2000 high values in a historical perspective. Potential fecundity, amounting to about 20 000-100 000 developing (vitellogenic) oocytes per fish and positively related to fish size, increased significantly with fish condition. Relative somatic potential fecundity (RF P, number of oocytes per g ovary-free body weight) in NSS herring was found to vary by 35-55% between years. Unexpectedly, females in 2000 showed low RF P-values, possibly due to negative feedback from previous reproductive investments at low condition. A clear threshold value for Fulton's condition factor, K (K=100×W/TL 3), of 0.65-0.70 existed below which there was considerable atresia (resorption of vitellogenic oocytes). Thus, these components of the spawning stock, amounting to 1-46% in the period 1980-1999, obviously contributed relatively little to the total egg production. This was confirmed by low ovary weights and examples of delayed oocyte development in these individuals. An up-to-date atresia model is presented. The established oocyte growth curve, and to a lesser degree the assumed atretic oocytic turnover rate, was critical for the estimation of realised fecundity (number of eggs spawned). Modelled realised fecundity was significantly below observed potential fecundity. Females that had migrated the shortest distance from the over-wintering area, Vestfjorden, northern Norway, were in the poorest condition, had the least developed oocytes and the lowest potential and realised fecundities. In agreement with previously published studies on temporal and spatial changes in gonad weights, those females reaching the main spawning grounds in the south-western part of the coast (Møre) were the most successful ones in terms of egg production. Likewise, present results on oocyte diameter confirmed that repeat spawners spawn first and recruit spawners second. Our histological analyses on oocyte microstructure provided further evidence that oocyte size is a precise and accurate maturation criterion in herring. The methodological examinations also showed that the level of atresia as well as potential fecundity from oocyte and ovarian size can be estimated by the binocular microscope. This study shows that there is a large range in size- and condition-specific egg production in NSS herring, which should be taken into account in further recruitment studies.

76 FR 20220 - New Formulas for Calculating the Basetime, Overtime, Holiday, and Laboratory Services Rates; Rate...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-12

... calculating the rates that it charges meat and poultry establishments, egg products plants, and importers and... establishments. The Egg Products Inspection Act (EPIA) (21 U.S.C. 1031 et seq.) provides for mandatory inspection of egg products processed at official plants. FSIS bears the cost of mandatory inspection provided...

Growth, reproduction, mortality, distribution, and biomass of freshwater drum in Lake Erie

USGS Publications Warehouse

Bur, Michael T.

1984-01-01

Predominant age-groups in the Lake Erie freshwater drum Aplodinotus grunnienspopulation were 3, 4, and 5 as determined from gill net, trap net, bottom trawl, and midwater trawl samples. Age and growth calculations indicated that females grew faster than males. However, the length-weight relation did not differ between sexes and was described by the equation: log W = −5.4383 + 3.1987 log L. Some males became sexually mature at age 2 and all were mature by age 6. Females matured 1 year later than males. Three sizes of eggs were present in ovaries; the average total number was 127,000 per female for 20 females over a length range of 270 to 478 mm. Seasonal analysis of the ovary-body weight ratio indicated that spawning extended from June to August. A total annual mortality rate of 49% for drum aged 4 through 11 was derived from catch-curve analysis. Freshwater drum were widely distributed throughout Lake Erie in 1977–1979, the greatest concentration being in the western basin. They moved into warm, shallow water (less than 10 m deep) during summer, and returned to deeper water in late fall. Summer biomass estimates for the western basin, based on systematic surveys with bottom trawls, were 9,545 t in 1977 and 2,333 t in 1978.

Warming modulates the effects of the endocrine disruptor progestin levonorgestrel on the zebrafish fitness, ovary maturation kinetics and reproduction success.

PubMed

Cardoso, P G; Rodrigues, D; Madureira, T V; Oliveira, N; Rocha, M J; Rocha, E

2017-10-01

Interactive effects between multiple stressors, namely climate drivers (e.g., temperature) and chemical pollution (e.g., endocrine disruptors) are poorly studied. Here, it was for the first time evaluated the combinatory effects of temperature and a synthetic progestin, levonorgestrel (LNG), on the fitness and reproductive-related endpoints of zebrafish (Danio rerio). A multi-factorial design was implemented by manipulating both temperature [setting as baseline an ambient temperature of 27 °C, against warming (+3 °C)] and LNG levels (10 ngL -1 and 1000 ngL -1 ). Groups of males and females were exposed sub-acutely, for 21-days. Increased temperature caused an overall decrease in the females' gonadosomatic index (GSI), during the pre-reproduction phase, LNG did not affect GSI. In addition, fecundity (number of ovulated eggs) was negatively affected by both temperature and LNG, being the effect of the latter more intense. Fish exposed to the highest LNG concentration (at both temperatures) did not reproduce, but also in those exposed to the lowest dose of progestin at a higher temperature, a complete reproductive failure occurred. These results reflect what was observed in the stereological analysis of the ovary maturation stages prior to reproduction. Accordingly, the higher the LNG concentration, the lower the degree of maturation of the ovary. This was exacerbated by the higher temperature. As to embryonated eggs, they hatched significantly faster at higher temperatures, but exposure to 10 ngL -1 of LNG (at 27 °C) reduced significantly the hatching rate, comparing to control. Further, the recrudescence of the ovary 48 h after spawning seems to be not affected by both stressors. Our data suggest that in a future scenario of global warming and synthetic hormones exposure, the reproduction of fish species, such as the zebrafish, can be endangered, which can put at risk their success, and consequently affect the structure and functioning of associated aquatic ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Body composition and reproductive performance at entry into lay of anno 1980 versus anno 2000 broiler breeder females under fast and slow release from feed restriction.

PubMed

Eitan, Y; Lipkin, Ehud; Soller, M

2014-05-01

During the 1990s, various disturbances arose affecting broiler breeder females at entry into lay. These disturbances were associated with even slight overfeeding during release of feed restriction in this critical maturation period. The present experiment was carried out to gain some insight into the causes of these disturbances by comparing the effect of fast (FF) and slow (SF) release from feed restriction at entry into lay in 2 broiler breeder populations: B1980, representing the genetic level of 1980, and B2000, the genetic level of 2000. Under the FF treatment, B1980 entered lay 19.2 d earlier than B2000; this increased to 37.4 d earlier under SF. The B1980 population entered lay at virtually the same mean age for SF and FF, whereas B2000 entered lay 15.7 d earlier under the FF. Body weight at first egg were 2,621 g for the B1980 and 3,591 g for B2000. Differences in BW at first egg between feeding treatments within lines were minor. As a percentage of BW, ovary, oviduct, and follicle weights were the same for B1980 and B2000; breast weight was 14.9% for B1980 and 21.2% for B2000; abdominal fat pad weight was 5.37% for B1980 and 2.67% for B2000. Follicle weight and absolute difference in weight between successive follicles was greater in B2000 than in B1980. It is concluded that body fat content does not limit entry into lay, and that threshold BW for onset of sexual maturity of broiler breeder hens increased by about 1,000 g between 1980 and 2000, indicating a tight association between juvenile growth rate and threshold BW for onset of sexual maturity. It is also concluded that disturbances at entry into lay due to overfeeding are not due to smaller differences between successive follicles in B2000 compared with B1980. There are hints, however, that overfeeding may contribute to these disturbances by decreasing differences between successive follicles.

Two Dimensional Finite Element Model to Study Calcium Distribution in Oocytes

NASA Astrophysics Data System (ADS)

Naik, Parvaiz Ahmad; Pardasani, Kamal Raj

2015-06-01

Cytosolic free calcium concentration is a key regulatory factor and perhaps the most widely used means of controlling cellular function. Calcium can enter cells through different pathways which are activated by specific stimuli including membrane depolarization, chemical signals and calcium depletion of intracellular stores. One of the important components of oocyte maturation is differentiation of the Ca2+ signaling machinery which is essential for egg activation after fertilization. Eggs acquire the ability to produce the fertilization-specific calcium signal during oocyte maturation. The calcium concentration patterns required during different stages of oocyte maturation are still not completely known. Also the mechanisms involved in calcium dynamics in oocyte cell are still not well understood. In view of above a two dimensional FEM model has been proposed to study calcium distribution in an oocyte cell. The parameters such as buffers, ryanodine receptor, SERCA pump and voltage gated calcium channel are incorporated in the model. Based on the biophysical conditions the initial and boundary conditions have been framed. The model is transformed into variational form and Ritz finite element method has been employed to obtain the solution. A program has been developed in MATLAB 7.10 for the entire problem and executed to obtain numerical results. The numerical results have been used to study the effect of buffers, RyR, SERCA pump and VGCC on calcium distribution in an oocyte cell.

Experimental life history and biological characteristics of Fasciola gigantica (Digenea: Fasciolidae).

PubMed

Phalee, Anawat; Wongsawad, Chalobol; Rojanapaibul, Amnat; Chai, Jong-Yil

2015-02-01

This study was conducted to investigate the life history, morphology, and maturation of larval stages and adult worms of Fasciola gigantica in experimental mice. Lymnaea auricularia rubiginosa was used as the intermediate host, and Oryza sativa was used for encystment of the metacercariae, while Mus musculus was used as the definitive host for maturation study. Fresh eggs from the gall bladder of water buffaloes fully developed into embryonated ones and hatched out at days 11-12 after incubation at about 29ºC. Free-swimming miracidia rapidly penetrated into the snail host, and gradually developed into the next larval stages; sporocyst, redia, and daughter redia with cercariae. Fully-developed cercariae were separated from the redia and shed from the snails on day 39 post-infection (PI). Free-swimming cercariae were immediately allowed to adhere to rice plants, and capsules were constructed to protect metacercariae on rice plants. Juvenile worms were detected in intestines of mice at days 3 and 6 PI, but they were found in the bile duct from day 9 PI. Juvenile and adult flukes were recovered from 16 mice experimentally infected with metacercariae, with the average recovery rate of 35.8%. Sexually mature adult flukes were recovered from day 42 PI. It could be confirmed that experimentally encysted metacercariae could infect and develop to maturity in the experimental host. The present study reports for the first time the complete life history of F. gigantica by an experimental study in Thailand. The obtained information can be used as a guide for prevention, elimination, and treatment of F. gigantica at environment and in other hosts.

Experimental Life History and Biological Characteristics of Fasciola gigantica (Digenea: Fasciolidae)

PubMed Central

Phalee, Anawat; Wongsawad, Chalobol; Rojanapaibul, Amnat; Chai, Jong-Yil

2015-01-01

This study was conducted to investigate the life history, morphology, and maturation of larval stages and adult worms of Fasciola gigantica in experimental mice. Lymnaea auricularia rubiginosa was used as the intermediate host, and Oryza sativa was used for encystment of the metacercariae, while Mus musculus was used as the definitive host for maturation study. Fresh eggs from the gall bladder of water buffaloes fully developed into embryonated ones and hatched out at days 11-12 after incubation at about 29ºC. Free-swimming miracidia rapidly penetrated into the snail host, and gradually developed into the next larval stages; sporocyst, redia, and daughter redia with cercariae. Fully-developed cercariae were separated from the redia and shed from the snails on day 39 post-infection (PI). Free-swimming cercariae were immediately allowed to adhere to rice plants, and capsules were constructed to protect metacercariae on rice plants. Juvenile worms were detected in intestines of mice at days 3 and 6 PI, but they were found in the bile duct from day 9 PI. Juvenile and adult flukes were recovered from 16 mice experimentally infected with metacercariae, with the average recovery rate of 35.8%. Sexually mature adult flukes were recovered from day 42 PI. It could be confirmed that experimentally encysted metacercariae could infect and develop to maturity in the experimental host. The present study reports for the first time the complete life history of F. gigantica by an experimental study in Thailand. The obtained information can be used as a guide for prevention, elimination, and treatment of F. gigantica at environment and in other hosts. PMID:25748710

Forecasting the spatial and seasonal dynamic of Aedes albopictus oviposition activity in Albania and Balkan countries.

PubMed

Tisseuil, Clément; Velo, Enkelejda; Bino, Silvia; Kadriaj, Perparim; Mersini, Kujtim; Shukullari, Ada; Simaku, Artan; Rogozi, Elton; Caputo, Beniamino; Ducheyne, Els; Della Torre, Alessandra; Reiter, Paul; Gilbert, Marius

2018-02-01

The increasing spread of the Asian tiger mosquito, Aedes albopictus, in Europe and US raises public health concern due to the species competence to transmit several exotic human arboviruses, among which dengue, chikungunya and Zika, and urges the development of suitable modeling approach to forecast the spatial and temporal distribution of the mosquito. Here we developed a dynamical species distribution modeling approach forecasting Ae. albopictus eggs abundance at high spatial (0.01 degree WGS84) and temporal (weekly) resolution over 10 Balkan countries, using temperature times series of Modis data products and altitude as input predictors. The model was satisfactorily calibrated and validated over Albania based observed eggs abundance data weekly monitored during three years. For a given week of the year, eggs abundance was mainly predicted by the number of eggs and the mean temperature recorded in the preceding weeks. That is, results are in agreement with the biological cycle of the mosquito, reflecting the effect temperature on eggs spawning, maturation and hatching. The model, seeded by initial egg values derived from a second model, was then used to forecast the spatial and temporal distribution of eggs abundance over the selected Balkan countries, weekly in 2011, 2012 and 2013. The present study is a baseline to develop an easy-handling forecasting model able to provide information useful for promoting active surveillance and possibly prevention of Ae. albopictus colonization in presently non-infested areas in the Balkans as well as in other temperate regions.

Egg freezing and egg banking: empowerment and alienation in assisted reproduction.

PubMed

Robertson, John A

2014-06-01

With the development of rapid freezing of human oocytes, many programs have reported IVF success rates comparable to those achieved with fresh eggs and thawed frozen embryos. Egg freezing is now gaining professional and regulatory acceptance as a safe and effective technique for women who wish to avoid discarding excess embryos, who face fertility-threatening medical treatments, or who want to preserve their eggs for use when they are better situated to have a family. This article focuses on the uses of and justification for egg freezing, the path to professional acceptance, the variability in success rates, and the controversy over freezing eggs for social rather than medical reasons. It also addresses the emergence of egg banking as a separate sector in the infertility industry, the regulatory issues that it poses, and its effect on egg donation. Key here is the legal control of stored eggs by banking women and their options when they wish to dispose of those eggs. The analysis is framed around empowerment and alienation. Egg freezing is generally empowering for women, but the donation or sale of unused eggs to infertile women, egg bankers, and researchers also raises issues of alienation.

Egg freezing and egg banking: empowerment and alienation in assisted reproduction

PubMed Central

Robertson, John A.

2014-01-01

With the development of rapid freezing of human oocytes, many programs have reported IVF success rates comparable to those achieved with fresh eggs and thawed frozen embryos. Egg freezing is now gaining professional and regulatory acceptance as a safe and effective technique for women who wish to avoid discarding excess embryos, who face fertility-threatening medical treatments, or who want to preserve their eggs for use when they are better situated to have a family. This article focuses on the uses of and justification for egg freezing, the path to professional acceptance, the variability in success rates, and the controversy over freezing eggs for social rather than medical reasons. It also addresses the emergence of egg banking as a separate sector in the infertility industry, the regulatory issues that it poses, and its effect on egg donation. Key here is the legal control of stored eggs by banking women and their options when they wish to dispose of those eggs. The analysis is framed around empowerment and alienation. Egg freezing is generally empowering for women, but the donation or sale of unused eggs to infertile women, egg bankers, and researchers also raises issues of alienation. PMID:27774158

Seasonal Occurrence and Interspecific Interactions of Egg Parasitoids of Megacopta cribraria (Heteroptera: Plataspidae) in Japan.

PubMed

Hoshino, Keisuke; Adati, Tarô; Olson, Dawn M; Takasu, Keiji

2017-06-01

We conducted a field study to determine seasonal egg parasitism rates of the kudzu bug Megacopta cribraria (F.) on the kudzu plant, Pueraria montana (Lour.) Merr. var. lobata (Willd.) Maesen et Almeida ex Sanjappa and Pradeep, in Tokyo, Japan, during the period from May 2014 to September 2014. The eggs of M. cribraria per 1 m2 of kudzu at four locations in Tokyo were collected weekly and parasitism rates were assessed. Eggs of M. cribraria were laid on the kudzu plant from May to September. Megacopta cribraria eggs were parasitized by two parasitoid species, Paratelenomus saccharalis (Dodd) and Ooencyrtus nezarae Ishii. Paratelenomus saccharalis first appeared in May, and its parasitism rates peaked in July and September. Ooencyrtus nezarae first appeared in June and its parasitism rates peaked in July. Except for one location which could not be statistically analyzed because of the small sample size, occurrence of parasitism by P. saccharalis and O. nezarae in M. cribraria egg masses was independent at one location and positively associated at two locations, suggesting that the use of host egg masses by P. saccharalis and O. nezarae is not mutually exclusive. Parasitism rates by P. saccharalis and O. nezarae were significantly lower for egg masses parasitized by both species than for those parasitized by a single species. The proportion of males among O. nezarae progeny was significantly higher for egg masses parasitized by O. nezarae together with P. saccharalis than for those parasitized by O. nezarae alone. These results suggest that parasitism of host egg masses by the two species is influenced by their interspecific interactions. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Learning from Experience: A Report from Mexico's Turtle Trip 2000.

ERIC Educational Resources Information Center

Jankowska, Marta Maja

2000-01-01

Fifteen high school students and adults from Idaho traveled to Mexico to assist the One World Workforce with monitoring the nests of olive ridley sea turtles. Only 1 percent of these endangered turtles mature to adulthood. The volunteers protected the eggs from poachers and helped the hatchlings get safely to the water. (TD)

Distribution of /sup 32/P in laboratory colonies of Solenopsis invicta (Hymenoptera: Formicidae) after feeding on labeled Heliothis zeal (Lepidoptera: Noctuidae) eggs: an explanation of discrepancies encountered in field predation experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nuessly, G.S.; Sterling, W.L.

1986-12-01

Factors responsible for low recovery rates of radioactive Solenopsis invicta Buren following placement of /sup 32/P-labeled Heliothis zea (Boddie) eggs on cotton in field predation tests were investigated using laboratory colonies of the ants. S. invicta workers became radioactive while handling labeled eggs by rupturing the egg chorion or by picking up labeled substances present on the surface of eggs. Foragers that removed the eggs from the plants picked up significantly more of the label than did workers that were sampled from the colonies between 12 and 72 h after egg introduction. Percentage of workers that became labeled over timemore » was much lower with the solid live food than in other studies that used powdered food sources. Problems in finding labeled ants in the field may have been associated with low mean levels of /sup 32/P per ant, together with difficulty in locating and isolating labeled ants from the population. Results indicate that egg predation rates estimated from counts per minute per predator have high variability, and suggest fairly large errors in estimates of eggs consumed per ant. Use of recovery rates of labeled predators to improve estimation of predation rates is discussed.« less

Effect of an artificial Ascaridia galli infection on egg production, immune response, and liver lipid reserve of free-range laying hens.

PubMed

Sharma, N; Hunt, P W; Hine, B C; McNally, J; Sharma, N K; Iqbal, Z; Normant, C; Andronicos, N M; Swick, R A; Ruhnke, I

2018-02-01

This study was conducted to determine the effect of Ascaridia galli infection on free-range laying hens. Lohmann Brown laying hens (n = 200) at 17 wk of age were allocated to 4 treatment groups (n = 50 per group), each with 5 replicate pens of 10 hens. Hens in 3 treatment groups were orally inoculated with different doses of embryonated A. galli eggs: low (250 eggs), medium (1,000 eggs), and high (2,500 eggs) levels, whereas hens of the control group were not infected. Infection levels were monitored using excreta egg counts and mature A. galli worm counts in the intestine. Anti A. galli antibody titers (IgY) in the serum were measured prior to infection, and at 6, 11, 15, and 20 wk post infection (PI) and in egg yolk at 11 and 20 wk PI. Parameters evaluated included feed intake, egg production, egg weight, egg mass, FCR, liver weight, liver fat, and intra epithelial immune cell infiltration. The results showed no difference in feed intake, body weight, or FCR among any treatment groups (P > 0.05). Egg production was lower in the low infection group compared to other groups at 20 wk of age (P < 0.01). Serum IgY was higher in the infected groups' hens at 20 wk PI compared to control group hens (P < 0.01). Yolk IgY increased significantly over time and was higher in infected hens compared to hens of the control group at 11 and 20 wk PI (P < 0.001). No differences were observed in liver lipid content or intraepithelial lymphocytes infiltration among treatment groups. Ascaridia galli eggs in the coprodeum content and adult A. galli worm count were higher in infected hens compared to hens of the control group (P < 0.01). In conclusion, the effects of artificial infection with A. galli on the parameters investigated were minor, and egg yolk antibody may be a more reliable indicator of A. galli infection than serum antibody or excreta egg count. © 2017 Poultry Science Association Inc.

Multiple vitellogenins from the Haemaphysalis longicornis tick are crucial for ovarian development.

PubMed

Boldbaatar, Damdinsuren; Umemiya-Shirafuji, Rika; Liao, Min; Tanaka, Tetsuya; Xuan, Xuenan; Fujisaki, Kozo

2010-11-01

Ovarian development and egg maturation are crucial processes for the success of reproduction in ticks. Three full-length cDNAs encoding the precursor of major yolk protein, vitellogenin, were obtained from cDNA libraries of the Haemaphysalis longicornis tick and designated as HlVg-1, HlVg-2 and HlVg-3. The HlVg mRNAs were found in fed females with major expression sites in the midgut, fat body and ovary. Native PAGE and Western blot demonstrated that HlVgs in the hemolymph, fat body and ovary of fed females consisted of four major polypeptides. RNAi results showed that HlVg dsRNA-injected ticks obtained lower body weight, egg weight and showed higher mortality of engorged females after blood sucking than control groups. Our results indicate that all HlVgs are essential for egg development and oviposition. Copyright 2010 Elsevier Ltd. All rights reserved.

Policosanol composition, antioxidant and anti-arthritic activities of milk thistle (Silybium marianum L.) oil at different seed maturity stages.

PubMed

Harrabi, Saoussem; Ferchichi, Azza; Bacheli, Asma; Fellah, Hayet

2018-04-16

Several anti-arthritic drugs and synthetic antioxidants have wide pharmaceutical uses and are often associated with various side effects on the human health. Dietary seed oils and their minor components like policosanol may offer an effective alternative treatment for arthritic and oxidative-stress related diseases. The biological effects of seed oils were affected by different parameters such as the stage of seed maturity. Hence, this study seeks to determine the policosanol content, antioxidant and anti-arthritic activities of milk thistle (Silybium marianum L.) oil extracted at various stages of seed maturation. Milk thistle oil samples were extracted from seeds collected at three maturation stages (immature, intermediate, and mature). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS) radical scavenging assays were used to determine the antioxidant activity of the extracted oils. The anti-arthritic activity of oil samples was evaluated with bovine serum protein denaturation and egg albumin denaturation methods. Gas chromatography coupled to mass spectrometry (GC-MS) was employed to determine the policosanol profile. Policosanol profile, antioxidant and anti-arthritic activities of milk thistle oil were influenced by the seed maturity stages. The oil extracted from the immature seeds had the highest total policosanol content (987.68 mg/kg of oil) and displayed the maximum antiradical activity (96.42% and 90.35% for DPPH test and ABTS assay, respectively). Nine aliphatic alcohols were identified in the milk thistle oil. The dominant poliosanol in the mature seed oil was octacosanol (75.44%), while triacontanol was the major compound (40.25%) in the immature seed oil. Additionally, the maximum inhibition of bovine serum protein denaturation (92.53%) and egg albumin denaturation (86.36%) were observed in immature seed oil as compared to mature seed oil. A high correlation was found between the total policosanol content, anti-arthritic activity and antioxidant capacity of oil. The milk thistle oil exhibited a potential anti-arthritic and antioxidant activities and that it might contribute to the protection of humans from a variety of diseases like rheumatoid arthritis. Also, it could serve as natural antioxidant and anti-arthritic agents for application in the food industries and pharmaceutic. Policosanol level in the seed oils might contribute to their anti-arthritic and antioxidant activities.

Status of intestinal helminthic infections of borderline residents in North Korea

PubMed Central

Li, Shunyu; Shen, Chenghua; Choi, Min-Ho; Bae, Young Mee; Yoon, Hiwon

2006-01-01

The present authors investigated intestinal parasitic infections among North Korean residents and refugees in China in 2003. The Kato-Katz method was applied to 236 residents and soldiers in a town on the North Korea-China border and to 46 people at a refugee camp in China. Only eggs of Ascaris and Trichuris were detected, with egg positive rates of 41.1% and 37.6%, respectively. The total egg positive rate was 55.0% and most of those who were egg positive were only lightly infected. Women of 61.2% and men of 53.1% were egg positive. The refugees from rural areas showed higher egg positive rates than those from urban areas. The present investigation confirmed high prevalence of soil-transmitted intestinal helminths in rural borderline areas of North Korea. PMID:16969068

Egg positive rate of Enterobius vermicularis and Taenia spp. by cellophane tape method in primary school children in Sivas, Turkey

PubMed Central

Aciöz, Mehmet; Değerli, Serpil; Alim, Ahmet; Aygan, Çetin

2005-01-01

The aim of the present study was to find out the number of students with enterobiasis and/or taeniasis in primary schools of Sivas. Among the 2,029 students in 6 primary schools, 316 (15.6%) were positive to Enterobius vermicularis eggs and 32 (1.6%) were positive to Taenia spp. eggs by the cellophane tape method. The egg positive rates of E. vermicularis and Taenia spp. ranged from 9.4% to 27.2% and from 0.8% to 2.6% respectively among six schools. The egg positive rate of E. vermicularis was found to be significantly different among these schools (χ2 = 31.96, P < 0.05), whereas there was no significant difference between the schools for Taenia spp. (χ2 = 4.37; P > 0.05). The rate (18.7%) of E. vermicularis in the urban slum regions was higher than the rate (11.5%) in the urban central regions (χ2 = 19.20; P < 0.05). Above results demonstrate that the egg positive rate of E. vermicularis and Taenia spp. was still prevalent among primary school children. PMID:15951641

Microscopic Examination of Gallbladder Stones Improves Rate of Detection of Clonorchis sinensis Infection

PubMed Central

Ma, Rui-hong; Luo, Xiao-bing; Zheng, Pei-ming; Luo, Zhen-liang; Yang, Liu-qing

2013-01-01

To improve the rate of detection of Clonorchis sinensis infection, we compared different specimens from patients with cholecystolithiasis. Feces, gallbladder bile, and gallbladder stones collected from 179 consecutive patients with cholecystolithiasis underwent microscopic examination, and according to the results, 30 egg-positive and 30 egg-negative fecal, gallbladder bile, and gallbladder stone specimens, respectively, underwent real-time fluorescent PCR. The detection rates of eggs in feces, bile, and gallbladder stones were 30.7%, 44.7%, and 69.8%, respectively, and the differences were statistically significant (P < 0.01). The PCR results confirmed that the eggs in the specimens were C. sinensis eggs. Eggs in the feces were “fresh” and in the gallbladder stones were “old.” Microscopic examination of gallbladder stones may improve the detection rates of C. sinensis infection, which is important for developing individualized treatments to prevent the recurrence of gallbladder stones and to prevent the occurrence of severe liver damage and cholangiocarcinoma. PMID:23698535

Effects of flour conditioning on cannibalism of T. castaneum eggs and pupae.

PubMed

Flinn, Paul W; Campbell, James F

2012-12-01

Cannibalism is a very important factor regulating population dynamics of the red flour beetle. After several days of feeding, the flour becomes conditioned by the beetles, which can affect rates of cannibalism. Flour conditioning is caused by an accumulation of feces, pheromones, and ethylquinone, which is a repellent produced by the beetles. We determined the effect of five different levels of flour conditioning on cannibalism of red flour beetle eggs and pupae by adult and larval stages. Larvae had the highest rates of egg cannibalism (12 eggs eaten over the 4-d period) followed by female adults (seven eggs consumed). Adult males had the lowest rates of cannibalism with only two eggs consumed. Cannibalism of eggs by females was correlated negatively with the level of flour conditioning. There was no effect of flour conditioning on egg or pupal cannibalism by larvae or adult males. Cannibalism by adult females may decrease as the level of flour conditioning increases because females may spend less time tunneling in highly conditioned flour and more time trying to disperse to other areas that are better for oviposition.

Crayfish (Orconectes virilis) predation on zebra mussels (Dreissena polymorpha)

USGS Publications Warehouse

Love, Joy; Savino, Jacqueline F.

1993-01-01

In laboratory studies, we quantified predation rates and handling time of crayfish (Orconectes virilis) on zebra mussels (Dreissena polymorpha) and rainbow trout (Oncorhhynchus mykiss) eggs. In single prey species tests, crayfish ate zebra mussels at similar rates as they ate rainbow trout eggs. When both prey were present, crayfish preferred rainbow trout eggs. Handling time of mussels was about twice that of rainbow trout eggs, and energetic content of mussels was lower. Therefore, net benefit for foraging on rainbow trout eggs was about three times that of foraging on zebra mussels.

Caspian tern reproduction in the Saginaw Bay ecosystem following a 100-year flood event

USGS Publications Warehouse

Ludwig, James P.; Auman, Heidi J.; Kurita, Hiroko; Ludwig, Matthew E.; Campbell, Loraine M.; Giesy, John P.; Tillitt, Donald E.; Jones, Paul; Yamashita, Nobu; Tanabe, Shinsuke; Tatsukawa, Ryo

1993-01-01

In the 2 years that followed the 100-year flood incident of September 1986 in the Saginaw River/Bay ecosystem, the reproduction of Caspian terns collapsed and then slowly recovered. Egg viability and fledging rates of hatched chicks were drastically depressed in 1987 and 1988. Eggs from clutches laid later in the year were less viable and chicks hatched from these eggs displayed wasting syndromes and deformities. The post-flood rate of deformities in hatched chicks in 1987–1989 was 163-fold greater than background rates for this population in 1962–1967. Embryonic abnormalities and deformities were found in many embryos recovered from dead eggs. Recently published data on planar toxic chemicals from samples of forage fish, tern eggs, and chicks from water birds nesting in the bay implicate planar dioxin-like PCBs 77 and 126 as the sources of these severe bioeffects. The planar PCB congeners accounted for >98% of TCDD-EQ toxicity in the tern eggs, and several were present at levels near or at the LD95 levels each for chicken eggs. Actual TCDD was about 1% of the TCDD-EQ toxicity. Very rapid buildup rates of PCBs were measured in tern eggs. The calculated toxic potency of PCB recovered from tern eggs was about 15-fold greater than parent aroclor 1242 PCB. Smaller tern species were projected to be much more at risk than the larger Caspian tern due to greater standard metabolic rates. The study supports the view that sediment disturbance and sediment banks of toxic chemicals are major threats to upper trophic level fish-eating species.

A new approach for the laboratory culture of the fathead minnow, Pimephales promelas.

PubMed

Gordon, Denise A; Smith, Mark E; Wratschko, Melissa; Agard, David; Holden, Lisa; Wilcox, Steve; Lazorchak, James M

2014-01-01

Fathead minnows are routinely cultured for use in aquatic toxicology studies. A new mass culture system described in the present study consisted of 6 stainless steel tanks, each containing 68 fish and 20 spawning substrates. Spawning results are compared with a previous system of 22 individual glass aquaria, which contained 16 fish and 4 spawning substrates per tank. During a 19-mo period, the new system produced an average of 4105 eggs/d, compared with an average of 2465 eggs/d with the previous system. Labor and maintenance were reduced with the new system. The stainless steel tanks eliminated aquaria glass breakage, and daily water use was reduced by 45%. Analysis of reference toxicant data from fish cultured using both systems indicated no change in the sensitivity of the test animals. Analyses of 2009 egg production data determined that a 6:1 to 7:1 female to male ratio had a significantly positive impact on egg production levels and that 6-mo-old breeding stock should be introduced to the spawning tanks in mid-spring for optimal egg production during the rest of the year. Implementing a stainless steel mass culture system significantly increased efficiency of egg production; reduced turnaround delay of mature animal availability for toxicity and molecular testing; and reduced labor time, costs, and inherent safety hazards, compared with glass aquaria systems. © 2013 SETAC.

The ontogeny of postmaturation resource allocation in turtles.

PubMed

Bowden, R M; Paitz, Ryan T; Janzen, Fredric J

2011-01-01

Resource-allocation decisions vary with life-history strategy, and growing evidence suggests that long-lived endothermic vertebrates direct resources toward growth and self-maintenance when young, increasing allocation toward reproductive effort over time. Few studies have tracked the ontogeny of resource allocation (energy, steroid hormones, etc.) in long-lived ectothermic vertebrates, limiting our understanding of the generality of life-history strategies among vertebrates. We investigated how reproductively mature female painted turtles (Chrysemys picta) from two distinct age classes allocated resources over a 4-yr period and whether resource-allocation patterns varied with nesting experience. We examined age-related variation in body size, egg mass, reproductive frequency, and yolk steroids and report that younger females were smaller and allocated fewer resources to reproduction than did older females. Testosterone levels were higher in eggs from younger females, whereas eggs from second (seasonal) clutches contained higher concentrations of progesterone and estradiol. These allocation patterns resulted in older, larger females laying larger eggs and producing second clutches more frequently than their younger counterparts. We conclude that resource-allocation patterns do vary with age in a long-lived ectotherm.

Toxicity of TFM lampricide to early life stages of walleye

USGS Publications Warehouse

Seelye, J.G.; Marking, L.L.; King, E.L.; Hanson, L.H.; Bills, T.D.

1987-01-01

The authors studied the effects of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) on gametes, newly fertilized eggs, eyed eggs, larvae, and swim-up fry of the walleye Stizostedion vitreum . When gametes from sexually mature walleyes were stripped into solutions of TFM, no effects were observed during the fertilization process at concentrations up to 3.0 mg/L - three times the concentration lethal to 99.9% of larval sea lampreys Petromyzon marinus held 12 h (LC99.9) under the same test conditions. Newly fertilized eggs likewise were unaffected during water hardening by concentrations of TFM that were lethal to sea lamprey ammocoetes. Eyed eggs, sac fry, and swim-up fry yielded LC25 values that were 2.5 to 5 times greater than the 12-h LC99.9 for sea lamprey ammocoetes. The data thus indicated that all of the early life stages of walleyes tested were considerably more resistant than sea lamprey ammocoetes to TFM, and that it is unlikely they would be adversely affected by standard stream treatments to kill sea lamprey ammocoetes.

Studies on some feed additives and materials giving partial protection against the suppressive effect of ochratoxin A on egg production of laying hens.

PubMed

Stoev, Stoycho D

2010-06-01

The protective effects of various feed supplements against the harmful effect of ochratoxin A on egg production and sexual maturation of two-weeks old Plymouth Rock female chicks designed for laying hens were studied. A significant protective effect of the feed additives or materials: water extract of artichoke (WEA), sesame seed (SS), Roxazyme-G (RG) and l-beta phenylalanine (PHE) against the suppressive effect of ochratoxin A (OTA) on egg production of laying hens was found. A similar protection was also seen on the toxic effect of OTA on various internal organs of the same hens. A significant protection was found against the decrease of the weight or the quantity of eggs as well as against the delay of the beginning of the laying period of chicks, both of which were provoked by ochratoxin A. These protective effects were strongest in chicks treated with SS or WEA, but were slightest in chicks treated with l-beta PHE. Copyright 2009 Elsevier Ltd. All rights reserved.

Cytoplasmic rearrangements associated with amphibian egg symmetrization

NASA Technical Reports Server (NTRS)

Malacinski, G. M.

1984-01-01

Cytoplasmic rearrangements which follow fertilization were mentioned in normal and inverted eggs. A set of yolk compartments was resolved by cytological analyses of both normally oriented and inverted eggs. Those compartments were characterized by their yolk platelet compositions and movement during egg inversion. It is found that during egg inversion the yolk compartments shift minor cytoplasmic compartments which line the egg cortex. Those yolk mass shifts occurred only after the inverted egg was activated. The direction of shift of the major yolk components, rather than the sperm entrance site, determines the dorsal/ventral polarity of the inverted egg. Among different spawnings the rate of shift varied. Eggs that displayed the fastest rate of shift exhibited the highest frequency of developmental abnormalities during organogenesis. Interpretation of novel observations on cytoplasmic organization provide criticism of some earlier models. A new density compartment model is presented as a coherent way to view the organization of the egg cytoplasm and the development of bilateral symmetry.

Detecting Coevolution in Mammalian Sperm–Egg Fusion Proteins

PubMed Central

CLAW, KATRINA G.; GEORGE, RENEE D.; SWANSON, WILLIE J.

2018-01-01

SUMMARY Interactions between sperm and egg proteins can occur physically between gamete surface-binding proteins, and genetically between gamete proteins that work in complementary pathways in which they may not physically interact. Physically interacting sperm–egg proteins have been functionally identified in only a few species, and none have been verified within mammals. Candidate genes on both the sperm and egg surfaces exist, but gene deletion studies do not support functional interactions between these sperm–egg proteins; interacting sperm–egg proteins thus remain elusive. Cooperative gamete proteins undergo rapid evolution, and it is predicted that these sperm–egg proteins will also have correlated evolutionary rates due to compensatory changes on both the sperm and egg. To explore potential physical and genetic interactions in sperm–egg proteins, we sequenced four candidate genes from diverse primate species, and used regression and likelihood methods to test for signatures of coevolution between sperm–egg gene pairs. With both methods, we found that the egg protein CD9 coevolves with the sperm protein IZUMO1, suggesting a physical or genetic interaction occurs between them. With regression analysis, we found that CD9 and CRISP2 have correlated rates of evolution, and with likelihood analysis, that CD9 and CRISP1 have correlated rates. This suggests that the different tests may reflect different levels of interaction, be it physical or genetic. Coevolution tests thus provide an exploratory method for detecting potentially interacting sperm–egg protein pairs. PMID:24644026

Detecting coevolution in mammalian sperm-egg fusion proteins.

PubMed

Claw, Katrina G; George, Renee D; Swanson, Willie J

2014-06-01

Interactions between sperm and egg proteins can occur physically between gamete surface-binding proteins, and genetically between gamete proteins that work in complementary pathways in which they may not physically interact. Physically interacting sperm-egg proteins have been functionally identified in only a few species, and none have been verified within mammals. Candidate genes on both the sperm and egg surfaces exist, but gene deletion studies do not support functional interactions between these sperm-egg proteins; interacting sperm-egg proteins thus remain elusive. Cooperative gamete proteins undergo rapid evolution, and it is predicted that these sperm-egg proteins will also have correlated evolutionary rates due to compensatory changes on both the sperm and egg. To explore potential physical and genetic interactions in sperm-egg proteins, we sequenced four candidate genes from diverse primate species, and used regression and likelihood methods to test for signatures of coevolution between sperm-egg gene pairs. With both methods, we found that the egg protein CD9 coevolves with the sperm protein IZUMO1, suggesting a physical or genetic interaction occurs between them. With regression analysis, we found that CD9 and CRISP2 have correlated rates of evolution, and with likelihood analysis, that CD9 and CRISP1 have correlated rates. This suggests that the different tests may reflect different levels of interaction, be it physical or genetic. Coevolution tests thus provide an exploratory method for detecting potentially interacting sperm-egg protein pairs. © 2014 Wiley Periodicals, Inc.

Techniques for identifying predators of goose nests

USGS Publications Warehouse

Anthony, R. Michael; Grand, J.B.; Fondell, T.F.; Miller, David A.

2006-01-01

We used cameras and artificial eggs to identify nest predators of dusky Canada goose Branta canadensis occidentalis nests during 1997-2000. Cameras were set up at 195 occupied goose nests and 60 artificial nests. We placed wooden eggs and domestic goose eggs that were emptied and then filled with wax or foam in an additional 263 natural goose nests to identify predators from marks in the artificial eggs. All techniques had limitations, but each correctly identified predators and estimated their relative importance. Nests with cameras had higher rates of abandonment than natural nests, especially during laying. Abandonment rates were reduced by deploying artificial eggs late in laying and reducing time at nests. Predation rates for nests with cameras were slightly lower than for nests without cameras. Wax-filled artificial eggs caused mortality of embryos in natural nests, but were better for identifying predator marks at artificial nests. Use of foam-filled artificial eggs in natural nests was the most cost effective means of monitoring nest predation. ?? Wildlife Biology (2006).

Short-term exposure to 17alpha-ethynylestradiol decreases the fertility of sexually maturing male rainbow trout (Oncorhynchus mykiss)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schultz, Irv R.; Skillman, Ann D.; Nicolas, Jean-Marc

The synthetic estrogen 17alpha-ethynylestradiol (EE2) is a commonly used oral contraceptive that has been increasingly detected in sewage effluents. This study determined whether EE2 exposure adversely affected reproduction in sexually maturing male rainbow trout (Oncorhynchus mykiss). We exposed male trout to graded water concentrations of EE2 (10, 100, and 1,000 ng/ L) for 62 d leading up to the time of spawning. Semen and blood plasma samples were removed from each fish. Semen was used to fertilize groups of eggs from one nonexposed female. As a measure of fertility, eggs were incubated for 28 d after fertilization to determine themore » proportion that attained the eyed stage of embryonic development. Additional endpoints also measured included sperm motility, spermatocrit, gonadosomatic and hepatosomatic indices, testis histology, and circulating plasma levels of the sex steroids 17alpha, 20beta-dihydroxyprogesterone (17,20-DHP) and 11-ketotestosterone (11-KT). Exposure to 1,000 ng/L of EE2 caused complete mortality of the treatment group by day 57. Exposure to lower EE2 water concentrations (10 and 100 ng/L) caused an increase in sperm density, while a significant reduction in testis mass was observed only in the 100-ng/L exposure group. Most significantly, semen harvested from fish exposed to 10 and 100 ng/L EE2 caused an approximately 50% reduction in the number of eggs attaining the eyed stage of embryonic development. Plasma levels of 17,20-DHP in exposed fish were roughly twice the level of the controls, while levels of 11-KT were significantly reduced in fish exposed to 100 ng/L EE2. These results suggest that sexually maturing male rainbow trout are susceptible to detrimental reproductive effects of short-term exposures to environmentally relevant levels of EE2.« less

Short-term exposure to 17 alpha-ethynylestradiol decreases the fertility of sexually maturing male rainbow trout (Oncorhynchus mykiss).

PubMed

Schultz, Irvin R; Skillman, Ann; Nicolas, Jean-Marc; Cyr, Daniel G; Nagler, James J

2003-06-01

The synthetic estrogen 17 alpha-ethynylestradiol (EE2) is a commonly used oral contraceptive that has been increasingly detected in sewage effluents. This study determined whether EE2 exposure adversely affected reproduction in sexually maturing male rainbow trout (Oncorhynchus mykiss). We exposed male trout to graded water concentrations of EE2 (10, 100, and 1,000 ng/ L) for 62 d leading up to the time of spawning. Semen and blood plasma samples were removed from each fish. Semen was used to fertilize groups of eggs from one nonexposed female. As a measure of fertility, eggs were incubated for 28 d after fertilization to determine the proportion that attained the eyed stage of embryonic development. Additional endpoints also measured included sperm motility, spermatocrit, gonadosomatic and hepatosomatic indices, testis histology, and circulating plasma levels of the sex steroids 17 alpha, 20 beta-dihydroxyprogesterone (17,20-DHP) and 11-ketotestosterone (11-KT). Exposure to 1,000 ng/L of EE2 caused complete mortality of the treatment group by day 57. Exposure to lower EE2 water concentrations (10 and 100 ng/L) caused an increase in sperm density, while a significant reduction in testis mass was observed only in the 100-ng/L exposure group. Most significantly, semen harvested from fish exposed to 10 and 100 ng/L EE2 caused an approximately 50% reduction in the number of eggs attaining the eyed stage of embryonic development. Plasma levels of 17,20-DHP in exposed fish were roughly twice the level of the controls, while levels of 11-KT were significantly reduced in fish exposed to 100 ng/L EE2. These results suggest that sexually maturing male rainbow trout are susceptible to detrimental reproductive effects of short-term exposures to environmentally relevant levels of EE2.

The role of egg-nest contrast in the rejection of brood parasitic eggs.

PubMed

Aidala, Zachary; Croston, Rebecca; Schwartz, Jessica; Tong, Lainga; Hauber, Mark E

2015-04-15

Hosts of avian brood parasites can avoid the reproductive costs of raising genetically unrelated offspring by rejecting parasitic eggs. The perceptual cues and controls mediating parasitic egg discrimination and ejection are well studied: hosts are thought to use differences in egg color, brightness, maculation, size and shape to discriminate between their own and foreign eggs. Most theories of brood parasitism implicitly assume that the primary criteria to which hosts attend when discriminating eggs are differences between the eggs themselves. However, this assumption is confounded by the degree to which chromatic and achromatic characteristics of the nest lining co-vary with egg coloration, so that egg-nest contrast per se might be the recognition cue driving parasitic egg detection. Here, we systematically tested whether and how egg-nest contrast itself contributes to foreign egg discrimination. In an artificial parasitism experiment, we independently manipulated egg color and nest lining color of the egg-ejector American robin (Turdus migratorius), a host of the obligate brood parasitic brown-headed cowbird (Molothrus ater). We hypothesized that the degree of contrast between foreign eggs and the nest background would affect host egg rejection behavior. We predicted that experimentally decreasing egg-nest chromatic and achromatic contrast (i.e. rendering parasitic eggs more cryptic against the nest lining) would decrease rejection rates, while increasing egg-nest contrast would increase rejection rates. In contrast to our predictions, egg-nest contrast was not a significant predictor of egg ejection patterns. Instead, egg color significantly predicted responses to parasitism. We conclude that egg-egg differences are the primary drivers of egg rejection in this system. Future studies should test for the effects of egg-nest contrast per se in predicting parasitic egg recognition in other host-parasite systems, including those hosts building enclosed nests and those parasites laying cryptic eggs, as an alternative to hypothesized effects of egg-egg contrast. © 2015. Published by The Company of Biologists Ltd.

Naïve hosts of avian brood parasites accept foreign eggs, whereas older hosts fine-tune foreign egg discrimination during laying

PubMed Central

2014-01-01

Background Many potential hosts of social parasites recognize and reject foreign intruders, and reduce or altogether escape the negative impacts of parasitism. The ontogenetic basis of whether and how avian hosts recognize their own and the brood parasitic eggs remains unclear. By repeatedly parasitizing the same hosts with a consistent parasitic egg type, and contrasting the responses of naïve and older breeders, we studied ontogenetic plasticity in the rejection of foreign eggs by the great reed warbler (Acrocephalus arundinaceus), a host species of the common cuckoo (Cuculus canorus). Results In response to experimental parasitism before the onset of laying, first time breeding hosts showed almost no egg ejection, compared to higher rates of ejection in older breeders. Young birds continued to accept foreign eggs when they were subjected to repeated parasitism, whereas older birds showed even higher ejection rates later in the same laying cycle. Conclusions Our results are consistent with the hypotheses that (i) naïve hosts need to see and learn the appearance of their own eggs to discriminate and reject foreign eggs, whereas (ii) experienced breeders possess a recognition template of their own eggs and reject parasitic eggs even without having to see their own eggs. However, we cannot exclude the possibility that other external cues and internal processes, accumulated simply with increasing age, may also modify age-specific patterns in egg rejection (e.g. more sightings of the cuckoo by older breeders). Future research should specifically track the potential role of learning in responses of individual hosts between first and subsequent breeding attempts by testing whether imprinting on a parasitized clutch reduces the rates of rejecting foreign eggs in subsequent parasitized clutches. PMID:25024736

Standard operating procedures for standardized mass rearing of the dengue and chikungunya vectors Aedes aegypti and Aedes albopictus (Diptera: Culicidae) - II - Egg storage and hatching.

PubMed

Zheng, Min-Lin; Zhang, Dong-Jing; Damiens, David D; Lees, Rosemary Susan; Gilles, Jeremie R L

2015-06-26

Management of large quantities of eggs will be a crucial aspect of the efficient and sustainable mass production of mosquitoes for programmes with a Sterile Insect Technique component. The efficiency of different hatching media and effectiveness of long term storage methods are presented here. The effect on hatch rate of storage duration and three hatching media was analysed: deionized water, boiled deionized water and a bacterial broth, using Two-way ANOVA and Post hoc Tukey tests, and the Pearson correlation coefficient was used to find the effect on the proportion of collapsed eggs. Two long term storage methods were also tested: conventional storage (egg paper strips stored in zip lock bags within a sealed plastic box), and water storage (egg papers in a covered plastic cup with deionized water). Regression analyses were used to find the effect of water storage and storage duration on hatch rate. Both species hatched most efficiently in bacterial broth. Few eggs hatched in deionized water, and pre-boiling the water increased the hatch rate of Ae. aegypti, but not Ae. albopictus. A hatch rate greater than 80% was obtained after 10 weeks of conventional storage in Ae. aegypti and 11 weeks in Ae. albopictus. After this period, hatching decreased dramatically; no eggs hatched after 24 weeks. Storing eggs in water produced an 85% hatch rate after 5 months in both species. A small but significant proportion of eggs hatched in the water, probably due to combined effects of natural deoxygenation of the water over time and the natural instalment hatching typical of the species. The demonstrated efficiency of the bacterial broth hatching medium for both Ae. albopictus and Ae. aegypti facilitates mass production of these two important vector species in the same facility, with use of a common hatching medium reducing cost and operational complexity. Similarly the increased hatch rate of eggs stored in water would allow greater flexibility of egg management in a large programme over the medium term, particularly if oxygenation of the water by bubbling oxygen through the storage tray could be applied to prevent hatching during storage.

Heat shock suppresses mating and sperm transfer in the rice leaf folder Cnaphalocrocis medinalis.

PubMed

Liao, H J; Qian, Q; Liu, X D

2014-06-01

Temperature is a key environmental factor in determining the population size of Cnaphalocrocis medinalis in summer. High temperatures inhibit survival, development and fecundity of this insect. However, biological responses of female and male adults to heat shock, and physiological mechanism of high temperature suppressing population development are still ambiguous. We experimentally tested the impact of heat shock (5 h day-1) on biological traits, spermatogenesis and sperm transfer of adults of C. medinalis. The result showed that heat exposure to 39 and 40 °C for 5 h reduced longevity and copulation frequency of adults, and hatchability of eggs. Immediate survival rate of males was lower than that of females after 3 days of exposure to 41 °C. The oviposition period, copulation frequency, fecundity of adults and hatchability of eggs were significantly lower when male adults were exposed to 40 or 41 °C for 3 days. Heat shock decreased frequency and success rate of mating when males were exposed, and it also resulted in postponement of mating behaviour and prolongation of mating duration as both the female and male adults were exposed. Heat shock did not affect spermatogenesis, but significantly inhibited sperms maturation. Moreover, males could not ejaculate sperm into females during copulation when these male moths received heat shock. Heat shock remarkably suppressed mating behaviour and sperm transfer, which led to a dramatic decline of rice leaf folder populations.

Age, growth, and maturity of round whitefish of the Apostle Islands and Isle Royale Regions, Lake Superior

USGS Publications Warehouse

Bailey, Merryll M.

1963-01-01

The round whitefish has been of some commercial importance in the upper Great Lakes but production in Lake Superior has generally been small; the United States average was 26,600 pounds for 1929-59. This study is based on 1,173 fish collected in the Apostle Islands in 1958-60 and 103 collected at Isle Royale in 1958 and 1960. The average age of 6.0 years at Isle Royale was concluded to be significantly higher than the mean of 4.2 years in the Apostle Islands. The body-scale relation is a straight line with an intercept of 1.1 inches on the length axis. Weight of Apostle Islands round whitefish captured in several months increased as the 3.22 power of the length. Growth in length was relatively slow; nearly or fully 7 years were required to reach an acceptable commercial length of 14 inches in both the Apostle Islands and at Isle Royale. The calculated weights at the end of the seventh year were 12.6 ounces in the Apostle Islands and 13.8 ounces at Isle Royale. Minimum length at maturity of male round whitefish (7.0-7.4 inches) was less than that of females (8.5-8.9 inches). At age-group II, 11.1 percent of male round whitefish, but only 1.5 percent of the females were mature. All males were mature as age-group V and all females as age-group VI. Males dominated the younger age groups but females were more numerous in the older ones. Estimates of the number of eggs in 37 round whitefish ovaries yielded an average of 5,330 eggs for fish 10.5-17.4 inches long.

Biochemical composition of deep-sea decapod crustaceans with two different benthic life strategies off the Portuguese south coast

NASA Astrophysics Data System (ADS)

Rosa, R.; Nunes, M. L.

2003-01-01

The objectives of the present study were to characterize the benthic life strategies of Aristeus antennatus (Crustacea: Penaeidea), Parapenaeus longirostris (Crustacea: Penaeidea) and Nephrops norvegicus (Crustacea: Astacidea) on the basis of biochemical composition (proximate chemical composition, total lipids, glycogen and cholesterol contents), and its response to biological and environmental factors (sex, maturation, reproduction, food availability and depth) into account. The specimens were collected at depths between 200 and 600 m off the Portuguese south coast (Algarve). The nektobenthic species ( A. antennatus and P. longirostris) showed higher protein, lipid, cholesterol and glycogen contents, and lower moisture content in the muscle than the benthic-endobenthic species ( N. norvegicus). Consequently, the energy content of the nektobenthic species was also higher. Principal component analyses were used to assess the relationship between the different biochemical contents and to relate them to the biotic and abiotic factors. Depth seems to have the most important role in the observed trends of the biochemical composition. The increase of the ovarian lipid levels occurs as a result of the maturation process. The highest values were obtained in mature N. norvegicus females. The differences can be due to maternal investment (lipid metabolism of the female is geared to the provision of egg lipid), since N. norvegicus produce large lecithotrophic eggs. The biochemical differences observed in the three species did not seem to be due to distinct trophic strategies, but instead were a consequence of depth, which may have a significant interspecific effect on food intake. It was also evident that reproductive cycle has profound effects upon the biochemistry of the three species. Gonadal maturation has large associated energy costs due to the increase in biosynthetic work. Moreover, the biochemical composition would be influenced by or synchronized with seasonal feeding activity or food availability.

Effects of Some Pesticides on Development of Ascaris suum Eggs

PubMed Central

Yu, Yong-Man; Kim, Jin-Won; Na, Won-Seok; Youn, Young-Nam; Choi, In-Wook

2014-01-01

To evaluate the effects of pesticides to parasite eggs, Ascaris suum eggs were incubated with 5 different pesticides (1:1,500-1:2,000 dilutions of 2% emamectin benzoate, 5% spinetoram, 5% indoxacarb, 1% deltamethrin, and 5% flufenoxuron; all v/v) at 20℃ for 6 weeks, and microscopically evaluated the egg survival and development on a weekly basis. The survival rate of A. suum eggs incubated in normal saline (control eggs) was 90±3% at 6 weeks. However, the survival rates of eggs treated with pesticides were 75-85% at this time, thus significantly lower than the control value. Larval development in control eggs commenced at 3 weeks, and 73±3% of eggs had internal larvae at 6 weeks. Larvae were evident in pesticide-treated eggs at 3-4 weeks, and the proportions of eggs carrying larvae at 6 weeks (36±3%-54±3%) were significantly lower than that of the control group. Thus, pesticides tested at levels similar to those used in agricultural practices exhibited low-level ovicidal activity and delayed embryogenesis of A. suum eggs, although some differences were evident among the tested pesticides. PMID:24623893

Impact of an atrazine-based herbicide on an agrobiont wolf spider.

PubMed

Godfrey, Jake A; Rypstra, Ann L

2018-06-01

For animals that live in association with humans, a key ecological question is how anthropogenic factors influence their life history. While major negative effects are obvious, subtle non-lethal responses to anthropogenic stimuli may provide insight into the features that lead to the success of species that thrive in habitats heavily impacted by humans. Here we explored the influence of the herbicide atrazine on various life history traits of a wolf spider that thrives in agroecosystems where it is commonly applied. We found that exposure delayed maturation and increased the probability of having molting errors. Atrazine also decreased the probability of producing an egg sac after mating, but increased the average mass of the initial egg sacs that were produced while not impacting the average number of eggs inside. The total number of eggs produced from a single mating on the other hand, was increased in the presence of atrazine through the production of multiple egg sacs. Finally, adult lifespan was shortened with exposure to atrazine. These results suggest that the atrazine based herbicides that are routinely applied to agricultural fields result in altered life history traits, potentially through endocrine disruption, that may counteract one another to allow persistence. Copyright © 2018 Elsevier Ltd. All rights reserved.

Atrazine reduces reproduction in fathead minnow (Pimephales promelas)

USGS Publications Warehouse

Tillitt, D.E.; Papoulias, D.M.; Whyte, J.J.; Richter, C.A.

2010-01-01

Atrazine, the widely used herbicide, has shown to affect the hypothalamus-pituitary-gonad axis in certain vertebrate species, but few studies have examined reproductive effects of this chemical on fish. Our study was designed to evaluate a population endpoint (egg production) in conjunction with histological (e.g., gonad development) and biochemical (e.g., hormone production) phenotypes associated with atrazine exposure in fathead minnows. Adult virgin breeding groups of 1 male and 2 females were exposed to nominal concentrations of 0, 0.5, 5.0, and 50 ??g/L of atrazine in a flow-through diluter for 14 or 30 days. Total egg production was lower (19-39%) in all atrazine-exposed groups as compared to the controls. The decreases in cumulative egg production of atrazine treated fish were significant by 17-20 days of exposure. Reductions in egg production in atrazine treatment groups were most attributable to reduced numbers of spawning events with increased atrazine exposure concentrations. Gonad abnormalities were observed in both male and female fish of atrazine-exposed fish. Our results also indicate that atrazine reduces egg production through alteration of final maturation of oocytes. The reproductive effects observed in this study warrant further investigation and evaluation of the potential risks posed by atrazine, particularly feral populations of fish from streams in agricultural areas with high use of this herbicide. ?? 2010.

Can reptile embryos influence their own rates of heating and cooling?

PubMed

Du, Wei-Guo; Tu, Ming-Chung; Radder, Rajkumar S; Shine, Richard

2013-01-01

Previous investigations have assumed that embryos lack the capacity of physiological thermoregulation until they are large enough for their own metabolic heat production to influence nest temperatures. Contrary to intuition, reptile embryos may be capable of physiological thermoregulation. In our experiments, egg-sized objects (dead or infertile eggs, water-filled balloons, glass jars) cooled down more rapidly than they heated up, whereas live snake eggs heated more rapidly than they cooled. In a nest with diel thermal fluctuations, that hysteresis could increase the embryo's effective incubation temperature. The mechanisms for controlling rates of thermal exchange are unclear, but may involve facultative adjustment of blood flow. Heart rates of snake embryos were higher during cooling than during heating, the opposite pattern to that seen in adult reptiles. Our data challenge the view of reptile eggs as thermally passive, and suggest that embryos of reptile species with large eggs can influence their own rates of heating and cooling.

The Effects of Biopolymer Encapsulation on Total Lipids and Cholesterol in Egg Yolk during in Vitro Human Digestion

PubMed Central

Hur, Sun-Jin; Kim, Young-Chan; Choi, Inwook; Lee, Si-Kyung

2013-01-01

The purpose of this study was to examine the effect of biopolymer encapsulation on the digestion of total lipids and cholesterol in egg yolk using an in vitro human digestion model. Egg yolks were encapsulated with 1% cellulose, pectin, or chitosan. The samples were then passed through an in vitro human digestion model that simulated the composition of mouth saliva, stomach acid, and the intestinal juice of the small intestine by using a dialysis tubing system. The change in digestion of total lipids was monitored by confocal fluorescence microscopy. The digestion rate of total lipids and cholesterol in all egg yolk samples dramatically increased after in vitro human digestion. The digestion rate of total lipids and cholesterol in egg yolks encapsulated with chitosan or pectin was reduced compared to the digestion rate of total lipids and cholesterol in other egg yolk samples. Egg yolks encapsulated with pectin or chitosan had lower free fatty acid content, and lipid oxidation values than samples without biopolymer encapsulation. Moreover, the lipase activity decreased, after in vitro digestion, in egg yolks encapsulated with biopolymers. These results improve our understanding of the effects of digestion on total lipids and cholesterol in egg yolk within the gastrointestinal tract. PMID:23965957

Salmonella and raw shell eggs: results of a cross-sectional study of contamination rates and egg safety practices in the United Kingdom catering sector in 2003.

PubMed

Elson, R; Little, C L; Mitchell, R T

2005-02-01

This study was prompted by epidemiological investigations of the unusual number of Salmonella Enteritidis outbreaks associated with the use of eggs in catering premises in England and Wales during 2002. The aims of the study, performed between April and May 2003, were to establish the rate of Salmonella contamination in raw shell eggs from catering premises, investigate any correlation between the origin and type of eggs and the presence of particular serotypes or phage types (PTs) of Salmonella, and examine the use of raw shell eggs in catering premises in the United Kingdom. A total of 34,116 eggs (5,686 pooled samples of six eggs) were collected from 2,104 catering premises, most of which were eggs produced in the United Kingdom (88%). Salmonella was isolated from 17 pools (0.3%) of eggs. Of these, 15 were Salmonella Enteritidis, which were further characterized to PTs as follows: PT6 (0.1%), PT4 (0.07%), PT12 (0.04%), PT1 (0.04%), and PT14b (0.02%). Salmonella Livingstone and Salmonella Typhimurium definitive type 7 resistant to ampicillin, streptomycin, sulfonamides, and tetracycline were also isolated. The Salmonella contamination rate of eggs produced in the United Kingdom appears to have decreased significantly since 1995 and 1996. This trend is reflected in the decrease of Salmonella Enteritidis and, in particular, Salmonella Enteritidis PT4. The impact of the United Kingdom Food Standards Agency's advice on the use of eggs, issued in January 2003, is discussed.

Skating through development.

PubMed

Ontiveros, Alejandra Elder; Blengini, Cecilia S; López-Tello, Jorge

2018-06-13

Oviparity is an ancestral reproductive strategy in which females lay fertilized eggs to the environment. During development, the offspring rely solely on the resources provided by the yolk sac to favour growth and maturation. This type of nutrition is also known as "lecithotrophy." This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The timing and location of spawning for the Euphausiid Thysanoessa spinifera off the Oregon coast, USA

NASA Astrophysics Data System (ADS)

Feinberg, Leah R.; Peterson, William T.; Tracy Shaw, C.

2010-04-01

Thysanoessa spinifera eggs were sampled biweekly from 1997-2005 along a transect extending off the coast of Newport, OR, USA. T. spinifera eggs were typically found in greatest abundance at NH05, our shallower mid-shelf station, and in lowest abundance at NH25, our offshore, deep-water station beyond the shelf break. In most years small peaks in density of T. spinifera eggs were found in late winter (February-March) and/or spring (April-May) along with large, prolonged peaks in summer, from July-September. However, it was more common to find egg densities of <1 m -3 or to find no eggs at all (58-91% of sampling dates per year had densities <1 m -3 at NH05). We found that egg densities were significantly positively correlated with chlorophyll a concentrations during the winter and spring ( r2=0.52 and 0.55 respectively, p<0.001), but not during summer. We did not find a significant correlation between egg densities and female densities. When winters were stormy, as in 1998, 1999 and 2000 the first eggs of Thysanoessa spinifera were not observed at any station until after upwelling was initiated later in the spring. However, in other years eggs were likely to be found earlier in the year if there were fewer storms, or winter or spring upwelling events that were not followed by a large storm. In most years, spawning continued until the upwelling season ended in the autumn, however this trend ceased in 2003-2005 and spawning was interrupted earlier in the season. Overall, we found that chlorophyll a peaks and egg peaks increased in magnitude in the later part of our study. We have concluded that T. spinifera is likely an intermittent spawner, whose ovaries are not constantly mature and prepared for spawning, despite the presence of ocean conditions that are suitable for spawning.

An evaluation of soybean lecithin as an alternative to avian egg yolk in the cryopreservation of fish sperm.

PubMed

Yildiz, Cengiz; Bozkurt, Yusuf; Yavas, Ilker

2013-08-01

Plant-derived lecithin has been used as a more sanitary alternative to avian egg yolk in livestock sperm cryopreservation protocols but its efficacy for cryopreserving fish sperm has not previously been tested comparatively. Here various concentrations of soybean lecithin were evaluated for the cryopreservation of carp (Cyprinus carpio) sperm. Sexually mature fish were induced to spermiation and ovulation with ovopel. The extenders were prepared by using 300 mM glucose, 10% DMSO, supplemented with different ratios of lecithin (5%, 10%, 15%, and 20%) and 10% egg yolk (control I). Negative control was made without egg yolk and soybean lecithin (control II). The pooled semen was diluted separately at ratio of 1:3 (v/v) by using egg yolk and soybean-based extenders. Diluted semen placed into 0.25 ml straws were equilibrated at 4 °C for 15 min and frozen in liquid nitrogen vapor. Fertilization was conducted using a ratio of 1 × 10(5)spermatozoa/egg. Supplementation of 10% lecithin to extender showed the best cryoprotective effect for sperm motility and duration of motility against freezing damage compared to 15%, 20% and control II groups (p<0.05). Cryopreserved sperm with extender containing 10% lecithin provided a greater result in terms of fertilization success when compared to extenders containing 20% lecithin or control II (p<0.05). It is concluded that the animal protein-free extender containing 10% soybean lecithin has a similar cryoprotective actions with conventional egg yolk-based extender against freezing damages and fertilization. Therefore, soybean lecithin is a suitable alternative to avian egg yolk for the cryopreservation of fish sperm. Copyright © 2013 Elsevier Inc. All rights reserved.

First assessment of trace metal concentration in mangrove crab eggs and other tissues, SE Brazil.

PubMed

de Almeida, Eduardo Vianna; Kütter, Vinicius Tavares; Marques, Eduardo Duarte; da Silva-Filho, Emmanoel Vieira

2016-07-01

The mangrove crab Ucides cordatus is widespread in the Brazilian coast, which has an important role in nutrient cycling. This species reproduces in summer and females carry eggs about a month, when they maintain contact with water and sediments. It remains unclear if trace metals can be absorbed or adsorbed by the eggs during development. The present study aims to investigate, for the first time, trace metal concentrations in ovigerous female tissues and eggs of U. cordatus in two areas with different metal pollution levels in the Southeastern Brazil. Samples were collected in two different mangroves, Guanabara Bay (GB) highly polluted environment and Paraíba do Sul River (PSR). In both populations, we observed significant increase of V, Cr, and Mn concentrations along eggs maturation. The higher metals averages were found in PSR population. This trend was reported since the 1990s and lower concentrations in GB marine organisms were attributed to reducing conditions, high organic load, and the presence of sulfide ions. These conditions restrict the bioavailability of metals in the bay, with exception of Mn. No significant differences were observed in gills and muscles. In both populations of the present study, V, Zn, As, and Pb were higher in eggs of initial stage, whereas Mn, Ni, Cu, and Cd were higher in hepatopancreas. Beside this, V, Cr, Mn, As, and Pb showed an increase concerning egg development. Thus, V, As, and Pb in eggs come from two sources previous discussed: females and environment. Zinc came mainly from females due to essential function. Those new information should be considered as one of the mechanisms of trace metal transfer to the trophic chain, between benthonic and pelagic environment.

Experimental shifts in egg-nest contrasts do not alter egg rejection responses in an avian host-brood parasite system.

PubMed

Hauber, Mark E; Aidala, Zachary; Igic, Branislav; Shawkey, Matthew D; Moskát, Csaba

2015-09-01

Obligate brood parasitic birds exploit their hosts to provide care for unrelated young in the nest. Potential hosts can reduce the cost of parasitism by rejecting foreign eggs from the nest. Observational, comparative, and experimental studies have concluded that most hosts use the coloration and patterning of eggshells to discriminate between own and foreign eggs in the nest. However, an alternative hypothesis is that birds use the colour contrasts between eggshells and the nest lining to identify parasitic eggs (egg-nest contrast hypothesis). In support of this hypothesis, we found that the avian perceivable chromatic contrasts between dyed eggs and unmanipulated nest linings significantly and negatively covaried with the rejection rates of different dyed eggs of the great reed warbler Acrocephalus arundinaceus, a frequently parasitized host of the common cuckoo Cuculus canorus. To experimentally test whether egg-nest contrasts influence rejection, we reciprocally dyed both eggs and the nest lining of this host species with one of two colours: orange and green. Contrary to the egg-nest contrast hypothesis, host rejection patterns in response to dyed eggs were not altered by dyeing nests, relative to unmanipulated control eggs and nests. In turn, experimental egg colour was the only significant predictor of egg rejection rate. Our results demonstrate that egg-nest contrast is a collateral, not a causal factor in egg rejection, and confirm the conclusions of previous studies that hosts can rely on the parasitic egg's appearance itself to recognize the foreign egg in the nest.

Toxicity of pesticides associated with potato production, including soil fumigants, to snapping turtle eggs (Chelydra serpentina).

PubMed

de Solla, Shane Raymond; Palonen, Kimberley Elizabeth; Martin, Pamela Anne

2014-01-01

Turtles frequently oviposit in soils associated with agriculture and, thus, may be exposed to pesticides or fertilizers. The toxicity of a pesticide regime that is used for potato production in Ontario on the survivorship of snapping turtle (Chelydra serpentina) eggs was evaluated. The following treatments were applied to clean soil: 1) a mixture of the pesticides chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos, and 2) the soil fumigant metam sodium. Turtle eggs were incubated in soil in outdoor plots in which these mixtures were applied at typical and higher field application rates, where the eggs were subject to ambient temperature and weather conditions. The pesticide mixture consisting of chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos did not affect survivorship, deformities, or body size at applications up to 10 times the typical field application rates. Hatching success ranged between 87% and 100% for these treatments. Metam sodium was applied at 0.1¯ times, 0.3¯ times, 1 times, and 3 times field application rates. Eggs exposed to any application of metam sodium had 100% mortality. At typical field application rates, the chemical regime associated with potato production does not appear to have any detrimental impacts on turtle egg development, except for the use of the soil fumigant metam sodium, which is highly toxic to turtle eggs at the lowest recommended application rate. © 2013 SETAC.

Diagnostic stages of the parasites of the Florida manatee, Trichechus manatus latirostris.

PubMed

Bando, Monica; Larkin, Iskande V; Wright, Scott D; Greiner, Ellis C

2014-02-01

Limited information is available on diagnostic stages of parasites in Florida manatees (Trichechus manatus latirostris). We examined 67 fecal samples from captive and wild manatees to define the diagnostic stages of the parasite fauna known to occur in Florida manatees. Parasite eggs were freshly extracted ex utero from identified mature helminths and subsequently characterized, illustrated, and matched to those isolated from fecal samples. In addition, coccidian oocysts in the fecal samples were identified. These diagnostic stages included eggs from 5 species of trematodes (Chiorchis fabaceus, Chiorchis groschafti, Pulmonicola cochleotrema, Moniligerum blairi, and Nudacotyle undicola), 1 nematode (Heterocheilus tunicatus), and oocysts of 2 coccidians (Eimeria manatus and Eimeria nodulosa).

Infertility treatment for azoospermic patients with a history of infectious parotitis (mumps) using combined techniques.

PubMed

Zhang, Shuiwen; Li, Jianhua; Zhou, Guoping; Qin, Silong; Xin, Nan; Guo, Junhong; Xu, Ye

2013-12-01

The purpose of this study was to investigate the clinical efficacy of in vitro maturation-intracytoplasmic sperm injection (IVM-ICSI) technique on the treatment of azoospermic patients with a history of infectious parotitis (mumps). Spermatozoa were obtained from the testes of azoospermic patients with a history of mumps and fertilized by ICSI. Eggs were retrieved from the spouse of patients in the natural cycle. Fertilized embryos were transferred into the uterus of patients' respective spouses. Live sperm were retrieved from 16 of out of 24 (67%) azoospermic patients with a history of mumps. Using IVM-ICSI, the normal fertilization rate was 71.2%. A total of 23 treatment cycles were completed in the spouses of 16 patients and of these, 9 patients' spouses became pregnant (a pregnancy rate of 39.1%). The success rate for infertility treatment of mumps patients was equally high at 56.3% (9/16). The IVM-ICSI technique is a simple, effective and economic method for infertility treatment in azoospermic patients with a history of mumps.

Effects of pre-incubation of eggs in fresh water and varying sperm concentration on fertilization rate in sterlet sturgeon, Acipenser ruthenus.

PubMed

Siddique, Mohammad Abdul Momin; Butts, Ian Anthony Ernest; Psenicka, Martin; Linhart, Otomar

2015-08-01

Standardization of fertilization protocols for sterlet Acipenser ruthenus is crucial for improving reproductive techniques and for conservation purposes. Our objectives were to determine the number of sperm (tested 430,000:1, 43,000:1, 4300:1, 430:1 sperm to egg) required to fertilize eggs and explore how pre-incubation of eggs in freshwater for 0min, 0.5min, 1min, and 10min interacts with different sperm ratios. Fertilization success ranged from 29.7% at 430:1 to 84.2% at 430,000:1. Pre-incubation time had no effect on fertilization success at 430,000:1 and 43,000:1 sperm to egg ratios, while it was significant at the 4300:1 and 430:1 ratios. The use of adequate experimental suboptimal sperm to egg ratio revealed a positive effect of pre-incubation time, such that at the 430:1 ratio, 0.5min pre-incubation increased the fertilization rate than 10min. At 0min pre-incubation the proportion of fertilized eggs increased at the 430,000:1 ratio, while at 1min fertilization increased at the 4300:1 ratio. At the 10min pre-incubation time, fertilization increased at the 43,000:1 ratio. Moreover, at the 0.5min pre-incubation time, the 43,000:1 ratio increased the fertilization rate than the 430:1 ratio. Generally, for 430:1 ratio, the fertilization rate is lower than in control. Transmission electron microscopy showed that pre-incubation of eggs in water for <10min does not trigger a cortical reaction or the formation of a perivitelline space. Results suggest that with a low sperm to egg ratio 0.5 to 1min pre-incubation of eggs in freshwater prior to fertilization can enhance fertilization rate of sterlet. Copyright © 2015 Elsevier B.V. All rights reserved.

Thiamine deficiency effects on the vision and foraging ability of lake trout fry

USGS Publications Warehouse

Tillitt, Donald E.; Zajicek, James L.; Claunch, Rachel; Honeyfield, Dale C.; Fitzsimons, John D.; Brown, Scott B.

2008-01-01

The exact causes of the historical recruitment failures of Great Lakes lake trout Salvelinus namaycush are unknown. Thiamine deficiency has been associated with neurological abnormalities in lake trout that lead to early mortality syndrome (EMS) in salmonine swim-up fry, and EMS-related mortality at the swim-up stage is a factor that contributes to the reproductive failure of lake trout populations in the Great Lakes. The potential for adverse effects of thiamine deficiency beyond the swim-up stage is unknown. We investigated the effects of low egg thiamine on behavioral functions in young, post-swim-up lake trout fry. The behavioral endpoints included visual acuity and prey capture rates in the same groups of lake trout fry from each family. Low-thiamine eggs were produced by feeding lake trout broodstock diets entailing thiaminase activity. The thiamine content of the spawned eggs ranged from 0.3 to 26.1 nmol/g. Both visual acuity and prey capture rates were affected by the thiamine content of the eggs. The visual acuity of lake trout was severely affected by low egg thiamine, mainly at thiamine concentrations below the threshold of 0.8 nmol/g but also at higher concentrations in field-collected eggs. Feeding was also reduced with low egg thiamine content. The reduction of prey capture rates was dramatic below 0.8 nmol/g and less dramatic, but still significant, in a portion of the families with egg thiamine concentrations of less than 5.0 nmol/g from both laboratory and field samples. Approximately one-third of the latter families had reduced feeding rates. Deficits in visual acuity may be part of the mechanism leading to decreased feeding rates in these fry. The effects of low egg thiamine on both of the behavioral endpoints studied increase the risk of low recruitment rates in Great Lakes lake trout populations.

Radiation of Bactrocera dorsalis (Diptera: Tephritidae) Eggs to Improve the Mass Rearing of Diachasmimorpha longicaudata (Hymenoptera: Braconidae).

PubMed

Cai, Pumo; Hong, Jingfang; Wang, Cong; Yang, Yanchuan; Zhang, Qiwen; Ji, Qinge; Chen, Jiahua

2018-05-28

This study explored the potential for Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) larvae hatched from irradiated eggs as hosts for Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae). B. dorsalis eggs of three different ages (12-, 24-, and 36-h old) were analyzed for hatchability, pupation rate, pupal weight, emergence rate, and sex ratio after exposure to different doses of radiation (5 and 10 Gy) at different dose rates (1 and 6 Gy/min). For the eggs of different ages exposed to radiation, only the hatchability and pupal weight of 36-h-old eggs exposed to the dose rate of 1 Gy/min were not affected; therefore, 6 Gy/min was not suitable for irradiating eggs. The viability of the parents and progenies of D. longicaudata when the parents were reared from 36-h-old eggs irradiated at nine different doses (0, 5, 10, 15, 20, 25, 30, 35, and 40 Gy) under laboratory conditions were investigated. The emergence percentage, sex ratio, and longevity of parasitoids developed from irradiated eggs were similar to those reared from nonirradiated hosts. A significant increase in larva mortality was observed for the eggs irradiated at doses above 25 Gy, and no redundant adult flies emerged at doses above 15 Gy. Hence, for B. dorsalis eggs to be applied in the mass rearing of D. longicaudata, the age of 36 h and a dose of 20-25 Gy are the optimal parameters. The results reveal that hosts and parasitoids need not be separated, enabling a reduction in cost, labor, and time and resulting in an improved mass rearing procedure for D. longicaudata.

Extreme intra-clutch egg size dimorphism is not coupled with corresponding differences in antioxidant capacity and stable isotopes between eggs.

PubMed

Poisbleau, Maud; Beaulieu, Michaël; Dehnhard, Nina; Demongin, Laurent; Lepoint, Gilles; Sturaro, Nicolas; Eens, Marcel

2017-03-01

Oviparous females need to allocate resources optimally to their eggs in order to maximize their fitness. Among these resources, dietary antioxidants, acquired by females and transferred to the eggs during egg formation, can greatly affect the development and survival of the embryo and chick. In crested penguins, incubation starts after the second and last egg is laid and, as opposed to many other bird species, this egg hatches first, thereby enhancing the survival of the chick. Here, we assessed whether antioxidant and isotopic composition could underlie these differences between eggs within clutches of southern rockhopper penguins (Eudyptes chrysocome chrysocome). The second-laid egg had higher total antioxidant capacity than the first-laid egg, although this was not due to higher antioxidant concentration but to its higher mass. This suggests that resources are allocated by females at a constant rate in both eggs within clutches. Accordingly, we found a strong correlation for isotopic compositions between eggs suggesting that resources were allocated similarly to each egg within the clutch. Overall, we found little evidence for a significant role of antioxidant and isotopic compositions to explain differences in terms of embryo/chick development between eggs in crested penguins. However, since our results suggest a constant rate of antioxidant transfer from females to eggs, limiting the mass of the first-laid egg might represent a strategy for females to spare antioxidant defences and preserve self-maintenance. Copyright © 2017 Elsevier Inc. All rights reserved.

Nitrogenous ovipositional deterrents in the leaves of sweet pepper (Capsicum annuum) at the mature stage against the leafminer, Liriomyza trifolii (Burgess).

PubMed

Dekebo, Aman; Kashiwagi, Takehiro; Tebayashi, Shin-ich; Kim, Chul-Sa

2007-02-01

Mature leaves of the sweet pepper, Capsicum annuum, exhibited resistance against the American serpentine leafminer, Liriomyza trifolii (Burgess), Agromyzidae. Based on bioassay-guided fractionation, three compounds, namely 4-aminobutanoic acid, (2S,4R)-4-hydroxy-1-methyl-2-pyrrolidine carboxylic acid and 4-amino-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone, were isolated from the leaves of sweet pepper. These compounds had significant oviposition deterrence towards adult flies of L. trifolii from laying their eggs on host plant leaves treated at 3.70, 16.60 and 6.45 microg/cm(2), respectively.

Copper-stimulated respiration in the unfertilized egg of the Eurasian perch, Perca fluviatilis (L).

PubMed

Akberali, H B; Earnshaw, M J

1984-01-01

The addition of Cu2+ (0.1-1.0 mM) to respiring, unfertilized eggs produced a marked stimulation in the rate of respiration whereas Zn2+ had no effect over the same concentration range. In the absence of Cu2+, temperature had little effect on unfertilized egg respiration but the Cu2+ stimulated respiratory rate showed the more normal response with a Q10 of 1.86 (10-20 degrees C). It appears that perch egg respiration is rate-limited by a physical event and it is suggested that Cu2+ may act by dissipating an oxygen permeability barrier located at the chorion.

Comparing life history characteristics of Lake Michigan’s naturalized and stocked Chinook Salmon

USGS Publications Warehouse

Kerns, Janice A; Rogers, Mark W.; Bunnell, David B.; Claramunt, Randall M.; Collingsworth, Paris D.

2016-01-01

Lake Michigan supports popular fisheries for Chinook Salmon Oncorhynchus tshawytscha that have been sustained by stocking since the late 1960s. Natural recruitment of Chinook Salmon in Lake Michigan has increased in the past few decades and currently contributes more than 50% of Chinook Salmon recruits. We hypothesized that selective forces differ for naturalized populations born in the wild and hatchery populations, resulting in divergent life history characteristics with implications for Chinook Salmon population production and the Lake Michigan fishery. First, we conducted a historical analysis to determine if life history characteristics changed through time as the Chinook Salmon population became increasingly naturalized. Next, we conducted a 2-year field study of naturalized and hatchery stocked Chinook Salmon spawning populations to quantify differences in fecundity, egg size, timing of spawning, and size at maturity. In general, our results did not indicate significant life history divergence between naturalized and hatchery-stocked Chinook Salmon populations in Lake Michigan. Although historical changes in adult sex ratio were correlated with the proportion of naturalized individuals, changes in weight at maturity were better explained by density-dependent factors. The field study revealed no divergence in fecundity, timing of spawning, or size at maturity, and only small differences in egg size (hatchery > naturalized). For the near future, our results suggest that the limited life history differences observed between Chinook Salmon of naturalized and hatchery origin will not lead to large differences in characteristics important to the dynamics of the population or fishery.

Entrainment of the Circadian Rhythm in Egg Hatching of the Crab Dyspanopeus sayi by Chemical Cues from Ovigerous Females.

PubMed

Forward, Richard B; Sanchez, Kevin G; Riley, Paul P

2016-02-01

The subtidal crab Dyspanopeus sayi has a circadian rhythm in larval release with a free-running period of 24.1 h. Under constant conditions, eggs hatch primarily in the 4-h interval after the time of sunset. The study tested the new model for entrainment in subtidal crabs, which proposes that the female perceives the environmental cycles and entrains the endogenous rhythm in the embryos. Results verified the model for D. sayi. Hatching by embryos collected from the field when they had not yet developed eye pigments, and were kept in constant conditions attached to their mother, exhibited the circadian hatching rhythm. Attached embryos could also be entrained to a new photoperiod in the laboratory before they developed eye pigments. Further, mature embryos removed from the female hatched rhythmically, indicating that a circadian rhythm resides in the embryos. However, if mature embryos with eye pigments were removed from the female and exposed to a new light-dark cycle, they could not be entrained to the new cycle; rather, they hatched according to the timing of the original light-dark cycle. Nevertheless, detached, mature embryos would entrain to a new light-dark cycle if they were in chemical, but not physical, contact with the female. Thus, the female perceives the light-dark cycle, and uses chemical cues to entrain the circadian rhythm of hatching by the embryos. © 2016 Marine Biological Laboratory.

Sperm and Spermatids Contain Different Proteins and Bind Distinct Egg Factors

PubMed Central

Teperek, Marta; Miyamoto, Kei; Simeone, Angela; Feret, Renata; Deery, Michael J.; Gurdon, John B.; Jullien, Jerome

2014-01-01

Spermatozoa are more efficient at supporting normal embryonic development than spermatids, their immature, immediate precursors. This suggests that the sperm acquires the ability to support embryonic development during spermiogenesis (spermatid to sperm maturation). Here, using Xenopus laevis as a model organism, we performed 2-D Fluorescence Difference Gel Electrophoresis (2D-DIGE) and mass spectrometry analysis of differentially expressed proteins between sperm and spermatids in order to identify factors that could be responsible for the efficiency of the sperm to support embryonic development. Furthermore, benefiting from the availability of egg extracts in Xenopus, we also tested whether the chromatin of sperm could attract different egg factors compared to the chromatin of spermatids. Our analysis identified: (1) several proteins which were present exclusively in sperm; but not in spermatid nuclei and (2) numerous egg proteins binding to the sperm (but not to the spermatid chromatin) after incubation in egg extracts. Amongst these factors we identified many chromatin-associated proteins and transcriptional repressors. Presence of transcriptional repressors binding specifically to sperm chromatin could suggest its preparation for the early embryonic cell cycles, during which no transcription is observed and suggests that sperm chromatin has a unique protein composition, which facilitates the recruitment of egg chromatin remodelling factors. It is therefore likely that the acquisition of these sperm-specific factors during spermiogenesis makes the sperm chromatin suitable to interact with the maternal factors and, as a consequence, to support efficient embryonic development. PMID:25244019

Cortical reaction as an egg quality indicator in artificial reproduction of pikeperch, Sander lucioperca.

PubMed

Zarski, Daniel; Krejszeff, Sławomir; Palińska, Katarzyna; Targońska, Katarzyna; Kupren, Krzysztof; Fontaine, Pascal; Kestemont, Patrick; Kucharczyk, Dariusz

2012-01-01

The aim of this study was to investigate the process of the cortical reaction in eggs of pikeperch, Sander lucioperca (L.), as well as the application of microscopic assessment of this process in egg quality evaluation. The analysis was carried out with eggs obtained from 10 females by artificial reproduction, in which hormonal stimulation with hCG was applied. Subsequently, each sample of eggs (separately from each female fish) was analysed. The analysis included observation of the cortical reaction and the process of egg swelling, and determination of the effect of temperature (12, 14 and 16°C) and the presence of spermatozoa on the cortical reaction. The results indicate that the cortical reaction in pikeperch eggs is quite violent, resulting in visible deformation of eggs between 3 and 5 min after activation. No effect of temperature or the presence of spermatozoa on the cortical reaction was observed. A strong correlation was recorded for the percentage of egg deformations observed and embryo survival rate. The described method of determination of pikeperch egg quality (based on egg deformation rate between 3 and 5 min after activation) may be highly useful, both in scientific research (where high-quality eggs are required) and in hatchery practice.

Spawning Cisco investigations in Canada waters of Lake Superior during 2007

USGS Publications Warehouse

Yule, Daniel L.; Evrard, Lori M.; Cholwek, Gary A.; Addison, Peter A.; Cullis, Ken I.

2008-01-01

Cisco Coregonus artedi form pre-spawning aggregations in Lake Superior during November with the bulk of spawning occurring during late November through early December (Dryer and Beil 1964). Eggs are broadcast into open water (Smith 1956) with fertilized eggs settling to the lakebed (Dryer and Beil 1964). Peak hatching occurs the following May (United States Geological Survey – Great Lakes Science Center, GLSC, unpublished data). Interannual variability in year class strength is high, but tends to be synchronous across different regions of Lake Superior (Bronte et al. 2003). November 2005 sampling of Thunder Bay showed 14 year-classes were present with the oldest fish being from the 1984 year-class (Yule et al. 2008). The ciscoes sampled were predominantly from five year classes that hatched during 1988, 1989, 1990, 1998, and 2003. These same strong year-classes were found in the western arm of Lake Superior during November 2006 (GLSC, unpublished data). Growth is rapid in the first few years of life with minimal growth after age-8 (Yule et al. 2008). Ciscoes exceeding 250 mm total length (TL) are typically sexually mature (Yule et al. 2006b, 2008). Thunder Bay ciscoes have high annual survival with rates for females and males averaging 0.80 and 0.75, respectively; females have higher rates of fishing-induced mortality compared to males but lower rates of natural mortality (Yule et al. 2008). Some Lake Superior stocks are currently commercially fished with the bulk of harvest occurring during November when fishers target females for their roe. The bulk of fish are harvested from Thunder Bay using suspended gillnets with mesh sizes ranging from 79-89 mm stretch measure. Ciscoes younger then age-5 make up a very small proportion (<0.1%) of the harvest (Yule, et al. 2008).

Egg rejection behavior in a population exposed to parasitism: Village Weavers on Hispaniola

USGS Publications Warehouse

Cruz, A.; Prather, J.W.; Wiley, J.W.; Weaver, P.F.

2008-01-01

In contrast to African Village Weavers (Ploceus cucullatus) that are parasitized by Diederik Cuckoos (Chrysococcyx caprius), introduced weavers on Hispaniola existed without parasitism for at least 2 centuries until the arrival of the Shiny Cowbird (Molothrus bonariensis) in the 1970s. Cruz and Wiley (1989) found that Hispaniolan weavers had a lower rejection rate of foreign eggs than African populations. Subsequently, Robert and Sorci (1999) and Lahti (2005, 2006) found that acceptance of dissimilar eggs is not characteristic of the species throughout its Hispaniolan range. In 1999-2002, we studied egg rejection in Hispaniolan weavers on a broad regional scale. Rejection increased as experimental eggs became increasingly different from the host eggs. Rejection rates for mimetic eggs, different color eggs, different-spotting eggs, and cowbird eggs was 23.2%, 33.3%, 61.5%, and 85.3%, respectively, with higher rejection of cowbird eggs in areas where cowbirds were observed. Although rejection is likely to have a genetic component, the differences could be due to phenotypic plasticity. Plasticity in egg rejection may be expected, given the potential cost of rejection and the spatiotemporal distribution of cowbirds. Thus, egg rejection has not necessarily decreased in Hispaniolan weavers, but it may act in a plastic manner, increasing where cowbirds are present. ?? The Author 2008. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.

Some quantitative indicators of postovulatory aging and its effect on larval and juvenile development of Atlantic salmon (Salmo salar).

PubMed

Mommens, Maren; Storset, Arne; Babiak, Igor

2015-07-01

Modern out-of-season egg production in Atlantic salmon (Salmo salar) increases the risk of postovulatory aging (POA) of oocytes. Postovulatory aging is known to influence oocyte quality in salmonids, but reliable tests for POA are lacking in Atlantic salmon egg production. To address this problem, we have collected oocytes from the same 20 Atlantic salmon females sequentially in approximately 1-week intervals, from the start of ovulation until 28 days postovulation (dpo), to determine the effect of natural retention of matured oocytes in body coelomic cavity on further performance of embryos and juveniles produced from those oocytes. Also, we investigated oocyte water hardening and several coelomic fluid parameters as potential quantitative indicators of POA. Oocyte quality decreased significantly from 22 dpo onward, as inferred from decrease in fertilization success and survival of embryos, alevins, and juveniles and increase in alevin and juvenile deformity rates. The occurrence of head deformities was significantly related to postovulatory age of oocytes. Coelomic fluid pH decreased significantly at 28 dpo and correlated positively with fertilization rates (r = 0.45), normal eyed embryo rates (r = 0.67), and alevin relative survival rates (r = 0.63) and negatively correlated with total alevin deformity rates (r = -0.59). Oocyte weight gain at 60 minutes decreased significantly at 28 dpo and correlated negatively with total alevin deformities and the occurrence of cranial nodules (r = -0.99). Generally, quality of ovulated oocytes remained stable for the first 2 weeks after ovulation. Later on, POA negatively influenced Atlantic salmon embryo, alevin, and juvenile performance. For the first time, we show a long-term effect of POA on salmonid juvenile performance. Standardized pH measurements of coelomic fluid could potentially improve embryo and juvenile production by identifying low-quality oocytes at an early stage during the production. Copyright © 2015 Elsevier Inc. All rights reserved.

Can Reptile Embryos Influence Their Own Rates of Heating and Cooling?

PubMed Central

Du, Wei-Guo; Tu, Ming-Chung; Shine, Richard

2013-01-01

Previous investigations have assumed that embryos lack the capacity of physiological thermoregulation until they are large enough for their own metabolic heat production to influence nest temperatures. Contrary to intuition, reptile embryos may be capable of physiological thermoregulation. In our experiments, egg-sized objects (dead or infertile eggs, water-filled balloons, glass jars) cooled down more rapidly than they heated up, whereas live snake eggs heated more rapidly than they cooled. In a nest with diel thermal fluctuations, that hysteresis could increase the embryo’s effective incubation temperature. The mechanisms for controlling rates of thermal exchange are unclear, but may involve facultative adjustment of blood flow. Heart rates of snake embryos were higher during cooling than during heating, the opposite pattern to that seen in adult reptiles. Our data challenge the view of reptile eggs as thermally passive, and suggest that embryos of reptile species with large eggs can influence their own rates of heating and cooling. PMID:23826200

High temperatures and absence of light affect the hatching of resting eggs of Daphnia in the tropics.

PubMed

Paes, Thécia A S V; Rietzler, Arnola C; Pujoni, Diego G F; Maia-Barbosa, Paulina M

2016-03-01

Temperature and light are acknowledged as important factors for hatching of resting eggs. The knowledge of how they affect hatching rates of this type of egg is important for the comprehension of the consequences of warming waters in recolonization of aquatic ecosystems dependent on dormant populations. This study aimed at comparing the influence of different temperature and light conditions on hatching rates of Daphnia ambigua andDaphnia laevis resting eggs from tropical environments. The ephippia were collected in the sediment of three aquatic ecosystems, in southeastern Brazil. For each lake, the resting eggs were exposed to temperatures of 20, 24, 28 and 32 °C, under light (12 h photoperiod) and dark conditions. The results showed that the absence of light and high temperatures have a negative influence on the hatching rates. Statistical differences for hatching rates were also found when comparing the studied ecosystems (ranging from 0.6 to 31%), indicating the importance of local environmental factors for diapause and maintenance of active populations.

Effect of the loading rate on compressive properties of goose eggs.

PubMed

Nedomová, Š; Kumbár, V; Trnka, J; Buchar, J

2016-03-01

The resistance of goose (Anser anser f. domestica) eggs to damage was determined by measuring the average rupture force, specific deformation and rupture energy during their compression at different compression speeds (0.0167, 0.167, 0.334, 1.67, 6.68 and 13.36 mm/s). Eggs have been loaded between their poles (along X axis) and in the equator plane (Z axis). The greatest amount of force required to break the eggs was required when eggs were loaded along the X axis and the least compression force was required along the Z axis. This effect of the loading orientation can be described in terms of the eggshell contour curvature. The rate sensitivity of the eggshell rupture force is higher than that observed for the Japanese quail's eggs.

Reproductive dynamics of Pacific sanddab, Citharichthys sordidus, off the central coast of California

NASA Astrophysics Data System (ADS)

Lefebvre, Lyndsey S.; Payne, Amber M.; Field, John C.

2016-01-01

Female Pacific sanddab were collected from the Monterey Bay, California to describe their reproductive strategy and annual reproductive cycle, as well as to estimate length at maturity, fecundity, spawning fraction (SF), and spawning interval (SI). Captive females were held to examine degradation of spawning markers and confirmed the biological spawning capabilities of the species. The reproductive season extended from May through January, as determined through macroscopic and histological examination of ovaries. Oocyte development was asynchronous, and an indeterminate fecundity pattern was displayed. Absolute and relative batch fecundity values were variable (means = 6663 eggs and 54 eggs g- 1 somatic weight, respectively) and significantly related to maternal length. During the period of highest reproductive activity, SF ranged from 0.42 to 0.98, suggesting some females were spawning on a daily basis. Monthly SF and SI were related to length, with smaller females having a truncated season and lower SF compared to larger females. Lengths at 50% (119 mm) and 95% (149 mm) maturity showed a downward shift relative to the 1940s, though the magnitude and cause of this shift remain unknown. This study highlights the importance of considering demographic shifts and size-related dynamics when modeling a stock's reproductive potential.

Copulation is necessary for the completion of a gonotrophic cycle in the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae).

PubMed

Sanches, Gustavo S; de Oliveira, Patrícia R; André, Marcos R; Machado, Rosangela Z; Bechara, Gervásio H; Camargo-Mathias, Maria I

2012-07-01

Ovarian development and egg maturation are essential stages in animal reproduction. For bisexual ixodid ticks, copulation is an important prerequisite for the completion of the gonotrophic cycle. In this study, we aimed to characterize the morpho-histological changes in the ovary and oocytes of the tick Rhipicephalus sanguineus, together with the identification of feeding and reproductive parameters associated with mating. Virgin and cross-mated females (with R. turanicus males) weighed 60% less at full engorgement than females mated conspecifically. In addition, the oocytes of these females did not develop to the same advanced stages as those of the conspecifically mated females. Sequencing of a 250-bp ITS-2 fragment in eggs that originated from a cross between an R. sanguineus female and an R. turanicus male showed a genotype similar (except by a deletion of 1 thymine) to that observed in the mother, arguing against fertilization by a trans-specific male. These findings suggest that male sex peptides are species-specific molecules that influence both full engorgement and oocyte maturation. Mechanical stimulation of the gonopore alone was insufficient for the completion of the entire process of vitellogenesis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Structures of asparagine-linked oligosaccharides from hen egg-yolk antibody (IgY). Occurrence of unusual glucosylated oligo-mannose type oligosaccharides in a mature glycoprotein.

PubMed

Ohta, M; Hamako, J; Yamamoto, S; Hatta, H; Kim, M; Yamamoto, T; Oka, S; Mizuochi, T; Matsuura, F

1991-10-01

Asparagine-linked oligosaccharides present on hen egg-yolk immunoglobulin, termed IgY, were liberated from the protein by hydrazinolysis. After N-acetylation, the oligosaccharides were labelled with a UV-absorbing compound, p-aminobenzoic acid ethyl ester (ABEE). The ABEE-derivatized oligosaccharides were fractionated by anion exchange, normal phase and reversed phase HPLC, and their structures were determined by a combination of sugar composition analysis, methylation analysis, negative ion FAB-MS, 500 MHz 1H-NMR and sequential exoglycosidase digestions. IgY contained monoglucosylated oligomannose type oligosaccharides with structures of Glc alpha 1-3Man7-9-GlcNAc-GlcNAc, oligomannose type oligosaccharides with the size range of Man5-9GlcNAc-GlcNAc, and biantennary complex type oligosaccharides with core region structure of Man alpha 1-6(+/- GlcNAc beta 1-4)(Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(+/- Fuc alpha 1-6)GlcNAc. The glucosylated oligosaccharides, Glc1Man8GlcNAc2 and Glc1Man7GlcNAc2, have not previously been reported in mature glycoproteins from any source.

Ovulation disorders: part I anovulation associated with estrogen deficiency.

PubMed

Check, J H

2007-01-01

To describe the diagnosis and treatment of anovulatory disorders associated with estrogen deficiency. Anovulation with estrogen deficiency was divided into two types: association with low vs. high serum gonadotropin levels. Treatments included bromocriptine or cabergoline for hyperprolactinemia and gonadotropins for normal prolactin levels. When gonadotropins were low, lowering the elevated serum FSH to restore down-regulated FSH receptors in the few remaining follicles with either ethinyl estradiol or GnRH agonists or antagonists was used. High serum FSH was followed by either close observation for spontaneous follicular maturation or low dose gonadotropin stimulation. Progesterone supplementation, especially by vaginal use, was given in the luteal phase. Though success in ovulation induction and pregnancies was greater in women with low FSH than high FSH, pregnancies following ovulation induction were nevertheless achieved even in women in apparent menopause. The use of ethinyl estradiol as opposed to other estrogen drugs has the advantage of not being able to be measured by most serum assays for estradiol allowing the physician to detect endogenous follicular development and thus determining when follicular maturation has been achieved. Even in the presence of marked diminished ovarian egg reserve, eggs from chronically younger women are superior in quality to women aged > or = 45.

Cannibalism and intraguild predation of eggs within a diverse predator assemblage.

PubMed

Takizawa, Tadashi; Snyder, William E

2011-02-01

Greater biodiversity among aphid predators sometimes leads to greater predator reproductive success. This could occur if cannibalism of predator eggs is consistently stronger than intraguild predation, such that diversity dilutes cannibalism risk when total predator densities remain constant across diversity levels. We compared the frequency of cannibalism versus intraguild predation by adult predators of four species [the lady beetles Coccinella septempunctata L. and Hippodamia convergens Guerin-Meneville, and the predatory bugs Geocoris bullatus (Say) and Nabis alternatus Parshley] on the eggs of three predator species (all of these predators but Nabis). For both coccinellid species, egg predation averaged across all intraguild predators was less frequent than cannibalism. In contrast, Geocoris eggs were generally more likely to be consumed by intraguild predators than by conspecifics. Closer inspection of the data revealed that Geocoris consistently consumed fewer eggs than the other species, regardless of egg species. Indeed, for lady beetle eggs it was relatively infrequent egg predation by Geocoris that brought down the average across all heterospecific predators, masking the fact that adults of the two lady beetles were no more likely to act as egg cannibals than as intraguild predators. Nabis ate eggs of the two beetles at approximately equal rates, but rarely ate Geocoris eggs. Female predators generally consumed more eggs than did males, but this did not alter any of the patterns described above. Altogether, our results suggest that species-specific differences in egg predation rates determined the relative intensity of egg intraguild-predation versus cannibalism, rather than any more general trend for egg cannibalism to always exceed intraguild predation. © 2011 Entomological Society of America

Caenorhabditis elegans as a model to study the impact of exposure to light emitting diode (LED) domestic lighting.

PubMed

Abdel-Rahman, Fawzia; Okeremgbo, Bethel; Alhamadah, Fatimah; Jamadar, Sakha; Anthony, Kevin; Saleh, Mahmoud A

2017-04-16

This study aimed to investigate the biological impact of exposure on domestic light emitting diodes (LED) lighting using the free-living nematode Caenorhabditis elegans as a model. Nematodes were separately exposed to white LED light covering the range of 380-750 nm, blue light at 450 nm and black light at 380-420 nm for one life cycle (egg to adult) with dark exposure as the control. Each light range induced stress to the nematode C. elegans such as reducing the number of the hatched eggs and/or delayed the maturation of the hatched eggs to the adult stage. In addition, it lowered or prevented the ability of adults to lay eggs and impaired the locomotion in the exposed worms. The observed type of biological stress was also associated with the production of reactive oxygen species (ROS) as compared to nematodes grown in the dark. It is concluded that the blue light component of white LED light may cause health problems, and further investigation is required to test commercial brands of white LEDs that emit different amounts of blue light.

Environmental and biological characteristics of Atlantic bluefin tuna and albacore spawning habitats based on their egg distributions

NASA Astrophysics Data System (ADS)

Reglero, Patricia; Santos, Maria; Balbín, Rosa; Laíz-Carrión, Raul; Alvarez-Berastegui, Diego; Ciannelli, Lorenzo; Jiménez, Elisa; Alemany, Francisco

2017-06-01

Tuna spawning habitats are traditionally characterized using data sets of larvae or gonads from mature adults and concurrent environmental variables. Data on egg distributions have never previously been used since molecular analyses are mandatory to identify tuna eggs to species level. However, in this study we use molecularly derived egg distribution data, in addition to larval data, to characterize hydrographic and biological drivers of the spatial distribution of eggs and larvae of bluefin Thunnus thynnus and albacore tuna Thunnus alalunga in the Balearic Sea, a main spawning area of these species in the Mediterranean. The effects of the hydrography, characterized by salinity, temperature and geostrophic velocity, on the spatial distributions of the eggs and larvae are investigated. Three biological variables are used to describe the productivity in the area: chlorophyll a in the mixed layer, chlorophyll a in the deep chlorophyll maximum and mesozooplankton biomass in the mixed layer. Our results point to the importance of salinity fronts and temperatures above a minimum threshold in shaping the egg and larval distribution of both species. The spatial distribution of the biotic variables was very scattered, and they did not emerge as significant variables in the presence-absence models. However, they became significant when modeling egg and larval abundances. The lack of correlation between the three biotic variables challenges the use of chlorophyll a to describe trophic scenarios for the larvae and suggests that the spatial distribution of resources is not persistent in time. The different patterns in relation to biotic variables across species and stages found in this and other studies indicate a still elusive understanding of the link between trophic levels involving tuna early larval stages. Our ability to improve short-term forecasting and long-term predictions of climate effects on the egg and larval distributions is discussed based on the consistency of the environmentally driven spatial patterns for the two species.

Transcript levels of the soluble sperm factor protein phospholipase C zeta 1 (PLCζ1) increase through induced spermatogenesis in European eel.

PubMed

Morini, Marina; Peñaranda, David S; Vílchez, María C; Gallego, Víctor; Nourizadeh-Lillabadi, Rasoul; Asturiano, Juan F; Weltzien, Finn-Arne; Pérez, Luz

2015-09-01

Activation at fertilization of the vertebrate egg is triggered by Ca(2+) waves. Recent studies suggest the phospholipase C zeta (PLCζ), a sperm-specific protein, triggers egg activation by an IP3-mediated Ca(2+) release and allow Ca(2+) waves at fertilization. In the present study we cloned, characterized, and phylogenetically positioned the European eel PLCζ (PLCζ1). It is 1521 bp long, with 10 exons encoding an open reading frame of 506 amino acids. The amino acid sequence contains an EF-hand domain, X and Y catalytic domains, and a carboxy-terminal C2 domain, all typical of other PLCζ orthologous. The tissue distribution was studied, and the gene expression was determined in testis during induced sexual maturation at three different thermal regimes. Also, brain and pituitary expression was studied through sex maturation at constant temperature. plcζ1 was expressed in brain of male and female, in testis but not in ovaries. By first time in vertebrates, it is reported plcζ1 expression in the pituitary gland. Testis plcζ1 expression increased through spermatogenesis under all the thermal regimes, but being significantly elevated at lower temperatures. It was very low when testis contained only spermatogonia or spermatocytes, while maximum expression was found during spermiogenesis. These results support the hypothesis for an eel sperm-specific PLCζ1 inducing egg activation, similarly to mammals and some teleosts, but different from some other teleost species, which express this protein in ovaries, but not in testes. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of thermal regime on ovarian maturation and plasma sex steroids in farmed white sturgeon, Acipenser transmontanus

USGS Publications Warehouse

Webb, M.A.H.; Van Eenennaam, J. P.; Feist, G.W.; Linares-Casenave, J.; Fitzpatrick, M.S.; Schreck, C.B.; Doroshov, S.I.

2001-01-01

Recently, commercial aquaculture farms in Northern California have exposed gravid, cultured white sturgeon females to cold water (12 ?? 1??C) throughout the late phase of vitellogenesis and ovarian follicle maturation resulting in improved ovulation rates and egg quality. However, the optimum timing for transfer of broodfish to the cold water and the capacity of transferred broodfish to maintain reproductive competence over an extended time in cold water had not been evaluated. Gravid white sturgeon females that have been raised at water temperatures of 16-20??C were transported to either cold water (12 ?? 1??C; Group 1) in November 1997 or maintained in ambient water temperatures (10-19??C; Group 2) until early spring. In March 1998, half of the fish in Group 2 had regressed ovaries, but the remaining females had intact ovarian follicles and were transported to the cold water. Ovarian follicles and blood were collected from females until they reached the stage of spawning readiness (determined by germinal vesicle position and an oocyte maturation assay) or underwent ovarian regression. Exposure of gravid sturgeon females to ambient water temperatures (14.5 ?? 2.3??C, mean ?? S.D.) from October to March led to a decrease in plasma sex steroids and a high incidence of ovarian regression in fish with a more advanced stage of oocyte development. Transfer of females with intact ovarian follicles to cold water (12 ?? 1??C) in the fall or early spring resulted in normal ovarian development in the majority of females. Holding females in cold water does not seem to override their endogenous reproductive rhythms but extends their capacity to maintain oocyte maturational competence over a longer period of time. A temperature-sensitive phase in ovarian development may occur during the transition from vitellogenic growth to oocyte maturation, and the degree and timing of sensitivity to environmental temperature are dependent on the female's endogenous reproductive rhythm. ?? 2001 Elsevier Science B.V. All Rights reserved.

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.

2014-12-15

Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each ofmore » which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes« less

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks.

PubMed

Que, Emily L; Bleher, Reiner; Duncan, Francesca E; Kong, Betty Y; Gleber, Sophie C; Vogt, Stefan; Chen, Si; Garwin, Seth A; Bayer, Amanda R; Dravid, Vinayak P; Woodruff, Teresa K; O'Halloran, Thomas V

2015-02-01

Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes.

Laminin Levels Regulate Tissue Migration and Anterior-Posterior Polarity during Egg Morphogenesis in Drosophila.

PubMed

Díaz de la Loza, María C; Díaz-Torres, Alfonsa; Zurita, Federico; Rosales-Nieves, Alicia E; Moeendarbary, Emad; Franze, Kristian; Martín-Bermudo, María D; González-Reyes, Acaimo

2017-07-05

Basement membranes (BMs) are specialized extracellular matrices required for tissue organization and organ formation. We study the role of laminin and its integrin receptor in the regulation of tissue migration during Drosophila oogenesis. Egg production in Drosophila involves the collective migration of follicle cells (FCs) over the BM to shape the mature egg. We show that laminin content in the BM increases with time, whereas integrin amounts in FCs do not vary significantly. Manipulation of integrin and laminin levels reveals that a dynamic balance of integrin-laminin amounts determines the onset and speed of FC migration. Thus, the interplay of ligand-receptor levels regulates tissue migration in vivo. Laminin depletion also affects the ultrastructure and biophysical properties of the BM and results in anterior-posterior misorientation of developing follicles. Laminin emerges as a key player in the regulation of collective cell migration, tissue stiffness, and the organization of anterior-posterior polarity in Drosophila. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

The Reproductive Morphology and Physiological Age Grading of the Female Salvinia Weevil, Cyrtobagous salviniae Calder and Sands

PubMed Central

Eisenberg, Lee; Johnson, Seth; Grodowitz, Michael J

2018-01-01

The morphology of the female Cyrtobagous salviniae Calder and Sands reproductive system is similar to other weevil species being meroistic and telotrophic. The reproductive system is composed of 2 ovaries each containing 2 ovarioles where the follicles mature. A physiological age grading system was developed where the continuum of ovarium development was divided into 2 nulliparous and 3 parous classes. This was based on the differentiation of the ovarioles, presence, and appearance of follicular relics, cuticle hardness/coloration, and fat body quantity/appearance. High correlation occurred between the parous classes and number of eggs produced where the P3 class had over 9-fold higher number of eggs in comparison with the P1 class. Mean number of eggs produced for each parous class was significantly different, however, overlap occurred. Such a system enables a determination of the past, present, and future reproductive status of field populations and mass-rearing colonies. PMID:29371784

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

PubMed Central

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.; Kong, Betty Y.; Gleber, Sophie C.; Vogt, Stefan; Chen, Si; Garwin, Seth A.; Bayer, Amanda R.; Dravid, Vinayak; Woodruff, Teresa K.; O’Halloran, Thomas V.

2015-01-01

Fertilization of a mammalian egg induces a series of ‘zinc sparks’ that are necessary for inducing the egg-to-embryo transition. Despite the importance of these zinc efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches to resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy dispersive spectroscopy, X-ray fluorescence microscopy, and 3D elemental tomography for high resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 106 zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes. PMID:25615666

The extraembryonic serosa protects the insect egg against desiccation

PubMed Central

Jacobs, Chris G. C.; Rezende, Gustavo L.; Lamers, Gerda E. M.; van der Zee, Maurijn

2013-01-01

Insects have been extraordinarily successful in occupying terrestrial habitats, in contrast to their mostly aquatic sister group, the crustaceans. This success is typically attributed to adult traits such as flight, whereas little attention has been paid to adaptation of the egg. An evolutionary novelty of insect eggs is the serosa, an extraembryonic membrane that enfolds the embryo and secretes a cuticle. To experimentally test the protective function of the serosa, we exploit an exceptional possibility to eliminate this membrane by zerknüllt1 RNAi in the beetle Tribolium castaneum. We analyse hatching rates of eggs under a range of humidities and find dramatically decreasing hatching rates with decreasing humidities for serosa-less eggs, but not for control eggs. Furthermore, we show serosal expression of Tc-chitin-synthase1 and demonstrate that its knock-down leads to absence of the serosal cuticle and a reduction in hatching rates at low humidities. These developmental genetic techniques in combination with ecological testing provide experimental evidence for a crucial role of the serosa in desiccation resistance. We propose that the origin of this extraembryonic membrane facilitated the spectacular radiation of insects on land, as did the origin of the amniote egg in the terrestrial invasion of vertebrates. PMID:23782888

Assessment of Chicken-Egg Membrane as a Dressing for Wound Healing.

PubMed

Guarderas, Fernando; Leavell, Yaowaree; Sengupta, Trisha; Zhukova, Mariya; Megraw, Timothy L

2016-03-01

To examine the efficacy of the folk remedy of chicken-egg membrane dressing on wound healing. Full-thickness excisional wounds were created on 14 male Sprague-Dawley rats in 2 separate trials. Each animal received 2 wounds on the upper back. One wound was untreated, and the other was dressed with chicken-egg membrane to assess its impact on wound healing. Half of the rats received egg membrane treatment on the inferior wound, whereas the other half received egg membrane treatment on the superior wound. Membrane replacement, wound debridement, and imaging were done on days 5, 8, and 10 and then imaging continued on days 12, 14, 16, 18, and 20 of the experiment. Healing rate was measured based on the wound area over the 20 days of the experiment. The wounds dressed with chicken-egg membrane had a significantly (P < .01) faster rate of healing compared with the control at the early stages of healing between days 0 and 5. This group healed 21% faster during this early phase, compared with the control group. Overall, however, wound healing rates were indistinguishable from days 5 to 20. Chicken-egg membrane dressing significantly improves healing of cutaneous wounds in the early stages of wound healing.

Deformities, PCBs, and TCDD-equivalents in double-crested cormorants (Phalacrocorax auritus) and Caspian terns (Hydroprogne caspia) of the Upper Great Lakes 1986–1991: Testing a cause-effect hypothesis

USGS Publications Warehouse

Ludwig, James P.; Kurita-Matsuba, Hiroko; Auman, Heidi J.; Ludwig, Matthew E.; Summer, Cheryl L.; Giesy, John P.; Tillitt, Donald E.; Jones, Paul D.

1996-01-01

Deformities have been reported in many species of colonial waterbirds from several localities on the Laurentian Great Lakes. The hypothesis that deformities were caused by either polychlorinated biphenyls (PCBs) or contaminants measured as 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs) is tested in this review of available data on concentrations of contaminants in eggs and observed deformities in embryos and chicks of double-crested cormorants (Phalacrocorax auritus) and Caspian terns (Hydroprogne caspia) between 1986 and 1991. Hatched chicks, live and dead eggs retrieved from 37 colonies in the upper Great Lakes were assessed for gross anatomical deformities. Rates of embryo death from seven regions of the upper Great Lakes were measured annually between 1986–1991. Half the embryos found dead in eggs were deformed. Nineteen types of abnormalities or deformities were observed. Subcutaneous edema in cormorants and gastroschisis in terns were the most common abnormalities in live or dead eggs. One of ten crossed-billed cormorant embryos survived to hatch. No bill-deformed terns hatched, although tern embryos had a greater rate of crossed-bills than cormorants. The suite of deformities and abnormalities found was similar to that produced in chickens by exposure to planar polychlorinated biphenyl (pPCB) and dioxin congeners. Hatching and deformity rates were correlated with concentrations ofpPCBs and TCDD-EQs. Planar PCB congeners that contributed most of the TCDD-EQs were present at concentrations sufficient to cause the observed effects. TCDD-EQs measured by H4IIE rat hepatoma cell 7-ethoxyresorufin O-deethylase (EROD) bioassay were highly correlated with deformity rates observed in cormorant chicks, live and dead eggs, and egg death rates. Similar correlations of TCDD-EQs with deformity rates were found in hatched tern chicks, dead eggs, and egg death rates, but not in live eggs. TCDD-EQs were more highly correlated to deformity and embryo death rates than total PCBs. The weight of evidence and these data are sufficient to reject the null hypothesis that there is no causal relationship between the incidence of deformities in cormorants and terns and exposure to planar halogenated compounds measured as TCDD-EQs or total PCBs in the Great Lakes.

Effects of gamma irradiation on the grape vine moth, Lobesia botrana, eggs

NASA Astrophysics Data System (ADS)

Mansour, M.; Al-Attar, J.

2012-11-01

Eggs of the grape vine moth, Lobesia botrana (Denis and Schiffermuller), ranging in age from 1-24 to 73-96 h, were exposed, at 24 h intervals, to gamma radiation ranging from 25-600 Gy. The effects of gamma radiation on egg hatch, pupation, adult emergence, sex ratio and rate of development were examined. Results showed that the radiosensitivity of the grape vine moth eggs decreased with increasing age and increased with increasing radiation dose. Egg hatch in 1-24 h old eggs was significantly affected at 25 Gy and completely prevented at 100 Gy. At the age of 25-48 h, radiation sensitivity was only a little lower; egg hatch at 100 Gy was <1% and at 125 Gy no egg hatch was observed. Egg sensitivity to gamma irradiation decreased significantly in the 49-72 h age group; egg hatch was 66% at 100 Gy, and 500 Gy did not completely stop egg hatch (<1%). Eggs irradiated a few hours before egg hatch (73-96 h old) were the most resistant; 150 Gy had no significant effect on egg hatch and at 600 Gy over 33% of the eggs hatched. When pupation or adult emergence was used as a criterion for measuring effectiveness, however, the effects of gamma radiation were very severe. In the most resistant age group (73-96 h old), 150 Gy completely prevented pupation and adult emergence and all larvae resulting from eggs irradiated <49 h old died before pupation. In addition, the rate of development of immature stages resulting from irradiated eggs was negatively affected and sex ratio was skewed in favor of males.

75 FR 55255 - Egg Research and Promotion Order; Referendum Procedures

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-10

...-0116] Egg Research and Promotion Order; Referendum Procedures AGENCY: Agricultural Marketing Service... Marketing Service (AMS) will use in conducting a referendum to determine whether egg producers favor increasing the assessment they pay to the American Egg Board (AEB) from a rate of 10 cents per 30- dozen case...

[Detection of Clonorchis sinensis eggs in the ground gallbladder stones by microscopy].

PubMed

Ma, Rui-Hong; Qiao, Tie; Luo, Xiao-Bing

2012-08-30

Sera, feces, bile and gallbladder stones were collected from 179 patients who accepted gallbladder-preserving cholelithotomy during the period of January to June 2010 at the general surgery department in the Second People's Hospital of Panyu District in Guangzhou. Rapid colloidal gold immunochromatography was used to detect IgG against Clonorchis sinensis. C. sinensis eggs were examined by fecal direct smear, and in bile sediments and ground gallbladder stones. The results showed that the positive rate of rapid colloidal gold immunochromatographic assay for IgG was 51.4%, and the egg positive rate in feces, bile sediments and gallbladder stones was 30.7%, 44.7% and 69.8%, respectively. The detection rate of fecal direct smear was the lowest, while that of the gallbladder stone examination was the highest (P < 0.05). Those patients with egg-positive feces and/or bile sediments were all with egg-positive gallbladder stones.

Voltage-clamp study of the activation currents and fast block to polyspermy in the egg of Xenopus laevis.

PubMed

Glahn, David; Nuccitelli, Richard

2003-04-01

Voltage-clamped mature, jelly-intact Xenopus eggs were used to carefully examine the ionic currents crossing the plasma membrane before, during, and after fertilization. The bulk of the fertilization current was transient, of large amplitude, and reversed at the predicted Cl- reversal potential. However, the large amplitude fertilization current was preceded by a small, step-like increase in holding current. This small increase in holding current is referred to in this paper as Ion to acknowledge its qualitative similarity to the Ion current previously described in the sea urchin. It was observed in both fertilized and artificially activated eggs, and was found to be unaffected by 10 mm tetra-ethyl ammonium (TEA), a concentration found to block K+ currents in Rana pipiens. Current-voltage relationships are presented for the large fertilization potential, and show that the fertilization currents have a marked outward rectification and are voltage sensitive. These properties are in contrast to the total lack of rectification and slight voltage sensitivity seen before or after the fertilization currents. The time required for sperm to fertilize the egg was found to be voltage dependent with a relatively more depolarized voltage requiring a longer time for fertilization to occur. The percentage of eggs blocked with varying potential levels was determined and this information was fitted to a modified Boltzmann equation having a midpoint of -9 mV.

Mapping the spawning grounds of North Sea cod (Gadus morhua) by direct and indirect means.

PubMed

Fox, Clive J; Taylor, Martin; Dickey-Collas, Mark; Fossum, Petter; Kraus, Gerd; Rohlf, Norbert; Munk, Peter; van Damme, Cindy J G; Bolle, Loes J; Maxwell, David L; Wright, Peter J

2008-07-07

Despite recent evidence for sub-stock structuring, North Sea cod are assessed as a single unit. As a consequence, knowledge of sub-stock trends is poor. In particular, there are no recent evaluations of which spawning grounds are active. Here we report results from the first ichthyoplankton survey to cover the whole North Sea. Also, this survey, conducted in 2004, was the first to make extensive use of DNA-based molecular methods to unambiguously identify early developmental stage cod eggs. We compare the findings from the plankton survey with estimated egg production inferred from the distribution of mature cod in contemporaneous trawl surveys. Results from both approaches were in general agreement and showed hot spots of egg production around the southern and eastern edges of the Dogger Bank, in the German Bight, the Moray Firth and to the east of the Shetlands. These areas broadly coincide with known spawning locations from the period 1940 to 1970. We were, however, unable to directly detect significant numbers of cod eggs at the historic spawning ground off Flamborough (northeast coast of England). The results demonstrate that most of the major spawning grounds of cod in the North Sea are still active but that some localized populations may have been reduced to the point where it is now difficult to detect the presence of eggs in the plankton.

Mapping the spawning grounds of North Sea cod (Gadus morhua) by direct and indirect means

PubMed Central

Fox, Clive J; Taylor, Martin; Dickey-Collas, Mark; Fossum, Petter; Kraus, Gerd; Rohlf, Norbert; Munk, Peter; van Damme, Cindy J.G; Bolle, Loes J; Maxwell, David L; Wright, Peter J

2008-01-01

Despite recent evidence for sub-stock structuring, North Sea cod are assessed as a single unit. As a consequence, knowledge of sub-stock trends is poor. In particular, there are no recent evaluations of which spawning grounds are active. Here we report results from the first ichthyoplankton survey to cover the whole North Sea. Also, this survey, conducted in 2004, was the first to make extensive use of DNA-based molecular methods to unambiguously identify early developmental stage cod eggs. We compare the findings from the plankton survey with estimated egg production inferred from the distribution of mature cod in contemporaneous trawl surveys. Results from both approaches were in general agreement and showed hot spots of egg production around the southern and eastern edges of the Dogger Bank, in the German Bight, the Moray Firth and to the east of the Shetlands. These areas broadly coincide with known spawning locations from the period 1940 to 1970. We were, however, unable to directly detect significant numbers of cod eggs at the historic spawning ground off Flamborough (northeast coast of England). The results demonstrate that most of the major spawning grounds of cod in the North Sea are still active but that some localized populations may have been reduced to the point where it is now difficult to detect the presence of eggs in the plankton. PMID:18397869

Anthelmintic activity of Chenopodium album (L) and Caesalpinia crista (L) against trichostrongylid nematodes of sheep.

PubMed

Jabbar, Abdul; Zaman, Muhammad Arfan; Iqbal, Zafar; Yaseen, Muhammad; Shamim, Asim

2007-10-08

The present study was carried out to determine the anthelmintic activity of Caesalpinia crista (L.) (Fabaceae) seed kernel and Chenopodium album (L.) (Chenopodiaceae) whole plant in order to justify their traditional use in veterinary medicine. In vitro anthelmintic activity of crude aqueous methanolic extract (AME) of both the plants was determined using mature Haemonchus contortus and their eggs in adult motility assay and egg hatch test, respectively. In vivo anthelmintic activity was evaluated in sheep naturally infected with mixed species of gastrointestinal nematodes by administering crude powder (CP) and AME in increasing doses (1.0-3.0 g/kg). Both plants exhibited dose- and time-dependent anthelmintic effects by causing mortality of worms and inhibition of egg hatching. Caesalpinia crista (LC50=0.134 mg/mL) was found to be more potent than Chenopodium album (LC50=0.449 mg/mL) in egg hatch test. In vivo, maximum reduction in eggs per gram (EPG) of faeces was recorded as 93.9 and 82.2% with Caesalpinia crista and Chenopodium album AME at 3.0 g/kg on day 13 and 5 post-treatment, respectively. Levamisole (7.5 mg/kg), a standard anthelmintic agent, showed 95.1-95.6% reduction in EPG. These data show that both Caesalpinia crista and Chenopodium album possess anthelmintic activity in vitro and in vivo, thus, justifying their use in the traditional medicine system of Pakistan.

Beyond size–number trade-offs: clutch size as a maternal effect

PubMed Central

Brown, Gregory P.; Shine, Richard

2009-01-01

Traditionally, research on life-history traits has viewed the link between clutch size and offspring size as a straightforward linear trade-off; the product of these two components is taken as a measure of maternal reproductive output. Investing more per egg results in fewer but larger eggs and, hence, offspring. This simple size–number trade-off has proved attractive to modellers, but our experimental studies on keelback snakes (Tropidonophis mairii, Colubridae) reveal a more complex relationship between clutch size and offspring size. At constant water availability, the amount of water taken up by a snake egg depends upon the number of adjacent eggs. In turn, water uptake affects hatchling size, and therefore an increase in clutch size directly increases offspring size (and thus fitness under field conditions). This allometric advantage may influence the evolution of reproductive traits such as growth versus reproductive effort, optimal age at female maturation, the body-reserve threshold required to initiate reproduction and nest-site selection (e.g. communal oviposition). The published literature suggests that similar kinds of complex effects of clutch size on offspring viability are widespread in both vertebrates and invertebrates. Our results also challenge conventional experimental methodologies such as split-clutch designs for laboratory incubation studies: by separating an egg from its siblings, we may directly affect offspring size and thus viability. PMID:19324614

Atrazine reduces reproduction in Japanese medaka (Oryzias latipes)

USGS Publications Warehouse

Papoulias, Diana M.; Tillitt, Donald E.; Talykina, Melaniya G.; Whyte, Jeffrey J.; Richter, Catherine A.

2014-01-01

Atrazine is an effective broadleaf herbicide and the second most heavily used herbicide in the United States. Effects along the hypothalamus–pituitary–gonad axis in a number of vertebrate taxa have been demonstrated. Seasonally elevated concentrations of atrazine in surface waters may adversely affect fishes, but only a few studies have examined reproductive effects of this chemical. The present study was designed to evaluate a population endpoint (egg production) in conjunction with histological (reproductive stage, gonad pathology) and biochemical (aromatase activity, sex hormone production) phenotypes associated with atrazine exposure in Japanese medaka. Adult virgin breeding groups of one male and four females were exposed to nominal concentrations of 0, 0.5, 5.0, and 50 μg/L (0, 2.3, 23.2, 231 nM) of atrazine in a flow-through diluter for 14 or 38 days. Total egg production was lower (36–42%) in all atrazine-exposed groups as compared to the controls. The decreases in cumulative egg production of atrazine-treated fish were significant by exposure day 24. Reductions in total egg production in atrazine treatment groups were most attributable to a reduced number of eggs ovulated by females in atrazine-treated tanks. Additionally, males exposed to atrazine had a greater number of abnormal germ cells. There was no effect of atrazine on gonadosomatic index, aromatase protein, or whole body 17 β-estradiol or testosterone. Our results suggest that atrazine reduces egg production through alteration of final maturation of oocytes. The reduced egg production observed in this study was very similar to our previously reported results for fathead minnow. This study provides further information with which to evaluate atrazine's risk to fish populations.

Spawning of zebra mussels (Dreissena polymorpha) and rearing of veligers under laboratory conditions

USGS Publications Warehouse

Nichols, S. Jerrine; Nalepa, Thomas F.; Schloesser, Donald W.

1992-01-01

The spawning cycle of the zebra mussel, Dreissena polymorpha, is amenable to laboratory manipulations. Techniques are presented that can be used to initiate spawning and rear veligers from fertilized egg to settlement stage. Spawning can be induced in sexually mature mussels by temperature flucuations or by the addition of ripe gametes. Embryonic survival is excellent until the straight-hinge stage when the first wave of mortality occurs, usually due to improper food. The second critical stage of development occurs just prior to settlement when mortality increases again. Veliger mortality averaged over 90% from egg to settlement. The results indicate that obtaining large numbers of veligers for laboratory experiments to be conducted year-round is difficult.

Irregularly calcified eggs and eggshells of Caiman latirostris (Alligatoridae: Crocodylia).

PubMed

Fernández, Mariela Soledad; Simoncini, Melina Soledad; Dyke, Gareth

2013-05-01

We describe irregularly calcified egg and eggshell morphologies for the first time in nests of the broad-snouted caiman, Caiman latirostris. Research is based on detailed descriptions of 270 eggs from a total sample of 46,800 collected between 2005 and 2011 in Santa Fe Province, Argentina, and encompasses animals from both natural habitats and held in captivity. We discuss possible reasons for the occurrence of eggs with different mineralisation patterns in our extensive C. latirostris field sample and its conservation significance; the chemistry of egg laying in amniotes is sensitive to environmental contamination which, in turn, has biological implications. Based on our egg sample, we identify two caiman eggshell abnormalities: (1) regularly calcified eggs with either calcitic nodules or superficial wrinkles at one egg end and (2) irregularly calcified eggs with structural gaps that weaken the shell. Some recently laid clutches we examined included eggs with most of the shell broken and detached from the flexible membrane. Most type 1 regularly calcified eggs lost their initial calcified nodules during incubation, suggesting that these deposits do not affect embryo survival rates. In contrast, irregularly calcified caiman eggs have a mean hatching success rate of 8.9% (range 0-38%) across our sample compared to a mean normal success of 75%. Most irregularly calcified caiman eggs probably die because of infections caused by fungi and bacteria in the organic nest material, although another possible explanation that merits further investigation could be an increase in permeability, leading to embryo dehydration.

Irregularly calcified eggs and eggshells of Caiman latirostris (Alligatoridae: Crocodylia)

NASA Astrophysics Data System (ADS)

Fernández, Mariela Soledad; Simoncini, Melina Soledad; Dyke, Gareth

2013-05-01

We describe irregularly calcified egg and eggshell morphologies for the first time in nests of the broad-snouted caiman, Caiman latirostris. Research is based on detailed descriptions of 270 eggs from a total sample of 46,800 collected between 2005 and 2011 in Santa Fe Province, Argentina, and encompasses animals from both natural habitats and held in captivity. We discuss possible reasons for the occurrence of eggs with different mineralisation patterns in our extensive C. latirostris field sample and its conservation significance; the chemistry of egg laying in amniotes is sensitive to environmental contamination which, in turn, has biological implications. Based on our egg sample, we identify two caiman eggshell abnormalities: (1) regularly calcified eggs with either calcitic nodules or superficial wrinkles at one egg end and (2) irregularly calcified eggs with structural gaps that weaken the shell. Some recently laid clutches we examined included eggs with most of the shell broken and detached from the flexible membrane. Most type 1 regularly calcified eggs lost their initial calcified nodules during incubation, suggesting that these deposits do not affect embryo survival rates. In contrast, irregularly calcified caiman eggs have a mean hatching success rate of 8.9 % (range 0-38 %) across our sample compared to a mean normal success of 75 %. Most irregularly calcified caiman eggs probably die because of infections caused by fungi and bacteria in the organic nest material, although another possible explanation that merits further investigation could be an increase in permeability, leading to embryo dehydration.

Investigation of thiamine and PCB association with early life stage fry mortality in lake trout from northwestern Lake Michigan in 1996-1998

USGS Publications Warehouse

Honeyfield, Dale C.; Beltman, Dong; Holey, Mark; Edsall, Carol C.

2005-01-01

Lake trout (Salvelinus namaycush) eggs were collected from 72 females near Sturgeon Bay, WI in northwestern Lake Michigan from 1996, 1997, and 1998 to determine the relationships between egg thiamine and polychlorinated biphenyl (PCB) concentrations with egg fertilization and hatch, prevalence of abnormal fry, and fry mortality. Fry mortality consistent with early mortality syndrome (EMS) was observed in eggs from 33% of the females in 1996, 25% in 1997, and 28% in 1998. Among egg lots exhibiting EMS, fry mortality averaged 95% in 1996, 63% in 1997 and 77% in 1998 compared to 2% or less in lots that did not exhibit EMS. Expression of EMS was strongly correlated with egg thiamine concentrations; egg lots with less than approximately 1 nmol/g total thiamine consistently exhibited high rates of EMS, whereas egg batches with greater than 1.5 nmol/g showed little or no incidence of EMS among swim-up fry. Egg thiamine concentration was not related to fertilization rate, egg hatch, or the prevalence of abnormal fry. There was no relationship between egg concentrations of PCBs or tetrachlorinated dibenzo-p-dioxin (TCDD) equivalents (from PCBs, dioxins, and furans) and any of the egg or fry viability measurements, including EMS. We concluded that fry mortality observed in Lake Michigan lake trout in 1996-1998 was not caused by the toxicity of PCBs, dioxins, and furans, but is due to low egg thiamine concentrations.

Effect of a commercial housing system on egg quality during extended storage.

PubMed

Jones, D R; Karcher, D M; Abdo, Z

2014-05-01

Egg producers in the United States are utilizing a variety of commercial egg production systems to provide consumer choice and meet legislative requirements. Consumer egg grades in the United States were developed for conventional cage production, and it is unclear what effect alternative production systems might have on egg quality during retail and consumer home storage. The current study was undertaken to determine what changes in egg quality characteristics occur during extended cold storage for commercially produced conventional cage, enriched colony cage, and cage-free aviary eggs. During 12 wk of cold storage, egg weight, albumen height, Haugh unit, static compression shell strength, vitelline membrane strength and deformation, yolk index, shell dynamic stiffness, and whole egg total solids were monitored. Overall, aviary and enriched eggs were significantly (P < 0.05) heavier than conventional cage. Albumen height and Haugh unit (P < 0.05) were significantly greater for conventional cage than enriched eggs. Static compression shell strength was greatest (P < 0.05) for enriched eggs compared with aviary. No overall housing system effects for yolk measurements, shell dynamic stiffness, or whole egg total solids were observed. Albumen height, Haugh unit, and yolk quality measurements were all greatest at 0 and lowest at 12 wk of storage (P < 0.05). The rate of quality change among the housing systems for each measured attribute at 4, 6, and 12 wk was determined. Other than differences in the change of egg weight at 4 wk, no significant differences in the rate of quality decline were found among the housing systems. The results of the current study indicate that current US egg quality standards should effectively define quality for commercially produced conventional cage, enriched colony cage, and cage-free aviary eggs.

Enhancing hatch rate and survival in laboratory-reared hybrid Devils Hole Pupfish through application of antibiotics to eggs and larvae

USGS Publications Warehouse

Feuerbacher, Olin; Bonar, Scott A.; Barrett, Paul J.

2017-01-01

We evaluated the effectiveness of four antibiotics in enhancing the hatch rate, larval survival, and adult survival of hybrid Devils Hole Pupfish Cyprinodon diabolis (hybridized with Ash Meadows Amargosa Pupfish C. nevadensis mionectes). Cephalexin (CEX; concentration = 6.6 mg/L of water), chloramphenicol (CAM; 50 mg/L), erythromycin (ERY; 12.5 mg/L), and trimethoprim sulfamethoxazole (TMP-SMX; 25 mg/L) were applied as a constant bath either to incubating eggs or to larvae that hatched from untreated eggs. Hatch rate was roughly doubled by incubation in the presence of CAM (68% hatch) and TMP-SMX (66%) relative to the control (28%). Cephalexin and ERY conferred no benefit upon the hatch rate. Among fry that hatched from treated eggs, there was no increase in 15-d larval survival. However, fish that hatched from eggs treated with CAM, ERY, and TMP-SMX demonstrated enhanced survival at 360 d (51.2, 38.4, and 43.6%, respectively) and at 540 d (22.6, 6.8, and 20.2%, respectively); the untreated control had no survivors to those time points. All groups of eggs treated with antibiotics showed reductions in bacterial colony-forming units (CFUs) at 24 h posttreatment. At 120 h posttreatment, CEX-treated eggs had CFU counts similar to those of the control, whereas the TMP-SMX-treated eggs had the lowest CFU counts. Eggs treated with CAM and ERY had similar CFU counts, which were significantly reduced from the control counts. Larvae that were treated with CAM and TMP-SMX within 12 h posthatch showed enhanced 15-d survival (74% and 72%, respectively) in comparison with the control (56%). For pupfish rearing efforts in which antibiotic use is appropriate, CAM and TMP-SMX appear to provide the greatest benefit, particularly when applied to incubating eggs rather than to hatched larvae.

Host responses to interspecific brood parasitism: a by-product of adaptations to conspecific parasitism?

PubMed Central

2014-01-01

Background Why have birds evolved the ability to reject eggs? Typically, foreign egg discrimination is interpreted as evidence that interspecific brood parasitism (IP) has selected for the host’s ability to recognize and eliminate foreign eggs. Fewer studies explore the alternative hypothesis that rejection of interspecific eggs is a by-product of host defenses, evolved against conspecific parasitism (CP). We performed a large scale study with replication across taxa (two congeneric Turdus thrushes), space (populations), time (breeding seasons), and treatments (three types of experimental eggs), using a consistent design of egg rejection experiments (n = 1057 nests; including controls), in areas with potential IP either present (Europe; native populations) or absent (New Zealand; introduced populations). These comparisons benefited from the known length of allopatry (one and a half centuries), with no gene flow between native and introduced populations, which is rarely available in host-parasite systems. Results Hosts rejected CP at unusually high rates for passerines (up to 60%). CP rejection rates were higher in populations with higher conspecific breeding densities and no risks of IP, supporting the CP hypothesis. IP rejection rates did not covary geographically with IP risk, contradicting the IP hypothesis. High egg rejection rates were maintained in the relatively long-term isolation from IP despite non-trivial rejection costs and errors. Conclusions These egg rejection patterns, combined with recent findings that these thrushes are currently unsuitable hosts of the obligate parasitic common cuckoo (Cuculus canorus), are in agreement with the hypothesis that the rejection of IP is a by-product of fine-tuned egg discrimination evolved due to CP. Our study highlights the importance of considering both IP and CP simultaneously as potential drivers in the evolution of egg discrimination, and illustrates how populations introduced to novel ecological contexts can provide critical insights into brood parasite-host coevolution. PMID:24834103

Host responses to interspecific brood parasitism: a by-product of adaptations to conspecific parasitism?

PubMed

Samas, Peter; Hauber, Mark E; Cassey, Phillip; Grim, Tomas

2014-01-01

Why have birds evolved the ability to reject eggs? Typically, foreign egg discrimination is interpreted as evidence that interspecific brood parasitism (IP) has selected for the host's ability to recognize and eliminate foreign eggs. Fewer studies explore the alternative hypothesis that rejection of interspecific eggs is a by-product of host defenses, evolved against conspecific parasitism (CP). We performed a large scale study with replication across taxa (two congeneric Turdus thrushes), space (populations), time (breeding seasons), and treatments (three types of experimental eggs), using a consistent design of egg rejection experiments (n = 1057 nests; including controls), in areas with potential IP either present (Europe; native populations) or absent (New Zealand; introduced populations). These comparisons benefited from the known length of allopatry (one and a half centuries), with no gene flow between native and introduced populations, which is rarely available in host-parasite systems. Hosts rejected CP at unusually high rates for passerines (up to 60%). CP rejection rates were higher in populations with higher conspecific breeding densities and no risks of IP, supporting the CP hypothesis. IP rejection rates did not covary geographically with IP risk, contradicting the IP hypothesis. High egg rejection rates were maintained in the relatively long-term isolation from IP despite non-trivial rejection costs and errors. These egg rejection patterns, combined with recent findings that these thrushes are currently unsuitable hosts of the obligate parasitic common cuckoo (Cuculus canorus), are in agreement with the hypothesis that the rejection of IP is a by-product of fine-tuned egg discrimination evolved due to CP. Our study highlights the importance of considering both IP and CP simultaneously as potential drivers in the evolution of egg discrimination, and illustrates how populations introduced to novel ecological contexts can provide critical insights into brood parasite-host coevolution.

Ecological, morphological, genetic and life history characteristics of two sockeye salmon populations, Tustumena Lake, Alaska

USGS Publications Warehouse

Woody, Carol Ann

1998-01-01

Populations can differ in both phenotypic and molecular genetic traits. Phenotypic differences likely result from differential selection pressures in the environment, whereas differences in neutral molecular markers result from genetic drift associated with some degree of reproductive isolation. Two sockeye salmon, Oncorhynchus nerka, populations were compared using both phenotypic and genotypic characters, and causal factors were examined. Salmon spawning in a short (<3 km), shallow (<21 cm), clear, homogenous spring-fed study site spawned later, were younger, smaller, and produced fewer and smaller eggs than salmon spawning in a longer (∼80 km), deeper, stained, diverse, precipitation-dominated stream. Run timing differences were associated with differences in stream thermal regimes. Age and size at maturity differences are likely due to differences in age-specific mortality rates. Fish in the shallow spring-fed system suffered higher adult predation rates and exhibited greater egg to fry survival compared to fish in the precipitation-fed system. Salmon in both streams exhibited non-random nest site selection for deeper habitats and smaller substrates (≥2 to <64 mm mean diameter) relative to available habitat; fish from the precipitation system avoided low velocity habitats containing fine (<2 mm) substrates. Genetic comparisons of six microsatellite loci indicated that run time was a more effective reproductive isolating mechanism than geographical distance. Differences between and within the tributary spawning populations are discussed in terms of selection, genetic drift, and the homogenizing effects of gene flow. This study indicates important adaptive differences may exist between proximate spawning groups of salmon which should be considered when characterizing populations for conservation or management purposes.

Incidence of climate on common frog breeding: Long-term and short-term changes

NASA Astrophysics Data System (ADS)

Neveu, André

2009-09-01

In Brittany (northwest France), the climate is showing a trend toward warming. This change is increasingly suspected to have a role in driving amphibian decline, but it is very difficult to determine at what level the climate affects the future of species. Recently, some studies have detected some direct effects on breeding phenology and indirect effects on energy allocation. The present study explores some of these effects on the common frog ( Rana temporaria) from 1984 to 2007. The results show two trends: a long-term change in breeding activities and a short-term influence due to the 2003 climatic anomaly. For the period of study, the start of egg-laying shows a precocity that was correlated with thermal conditions during the preceding 40 days as well as milder springs during the previous year. This degree of precocity is currently the highest found in Europe (+26.6 days). As a result of the 2003 heat wave, the clutch mean fecundity in 2004 was smaller than for other years, the fecundity rates were reduced and abortions were numerous (unlike other years). Moreover, young females were the smallest observed in recent years and some females seemed to exhibit a trade-off between fecundity and growth. Before or after egg-laying, female body condition and mean weight of mature ovules were both lower. The year 2005 appears as a transition period before the recovery in 2006-2007. The results show that climate warming endangers the vital rates of the common frog, while the 2003 climatic events seem more detrimental than the long-term warming trend.

9 CFR 592.510 - Base time rate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Base time rate. 592.510 Section 592... PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.510 Base time rate. The base time rate for voluntary inspection services for egg products is $47.79 per hour per program...

Latitudinal patterns in the life-history traits of three isolated Atlantic populations of the deep-water shrimp Plesionika edwardsii (Decapoda, Pandalidae)

NASA Astrophysics Data System (ADS)

González, José A.; Pajuelo, José G.; Triay-Portella, Raül; Ruiz-Díaz, Raquel; Delgado, João; Góis, Ana R.; Martins, Albertino

2016-11-01

Patterns in the life-history traits of the pandalid shrimp Plesionika edwardsii are studied for the first time in three isolated Atlantic populations (Madeira, Canaries and Cape Verde Islands) to gain an understanding of their latitudinal variations. The maximum carapace size of the populations studied, as well as the maximum weight, showed clear latitudinal patterns. The patterns observed may be a consequence of the temperature experienced by shrimps during development, 1.37 ° C higher in the Canaries and 5.96 ° C higher in the Cape Verde Islands than in Madeira. These temperature differences among populations may have induced phenotypic plasticity because the observed final body size decreased as the temperature increased. A latitudinal north-south pattern was also observed in the maximum size of ovigerous females, with larger sizes found in the Madeira area and lower sizes observed in the Cape Verde Islands. A similar pattern was observed in the brood size and maximum egg size. Females of P. edwardsii produced smaller eggs in the Cape Verde Islands than did those at the higher latitude in Madeira. P. edwardsii was larger at sexual maturity in Madeira than in the Cape Verde Islands. The relative size at sexual maturity is not affected by latitude or environmental factors and is the same in the three areas studied, varying slightly between 0.568 and 0.585. P. edwardsii had a long reproductive season with ovigerous females observed all year round, although latitudinal variations were observed. Seasonally, there were more ovigerous females in spring and summer in Madeira and from winter to summer in the Cape Verde Islands. P. edwardsii showed a latitudinal pattern in size, with asymptotic size and growth rate showing a latitudinal compensation gradient as a result of an increased growth performance in the Madeira population compared to that of the Cape Verde Islands.

[Occurrence of enteritis-causing salmonellae in food and in domestic animals in 1991].

PubMed

Hartung, M

1993-07-01

The control of salmonellae in foods and animals in Germany, 1991, is based on voluntary contributions of veterinary institutions, e. g. governmental investigation centres, universities, agricultural institutions and slaughter-house laboratories. The results of questionnaire-based evaluations are presented (s. a. HARTUNG, 1993 a). Also reported were 101 outbreaks involving 2272 cases of salmonellosis (fig. 1), of which 92% were caused by S. enteritidis. 46% of the cases were caused by egg and egg-containing meals, 24% by bakery products, often containing raw eggs. From poultry meat the organism was only isolated in less than 1% of the known cases. Meat and meat products (10%) and milk (5%) were further sources of infection. Summarizing it can be assumed that in 70% of the cases the cause of foodborne salmonellosis were meals prepared with raw eggs. The mean salmonella rate in routine food investigations was 0.88% (tab. 1). Poultry had a salmonella rate of 13% and eggs, incl. egg-containing dishes, a rate of 1%. All other food groups were contaminated with salmonella at the level of the mean rate (meat and meat products) or less (fish and milk and their products: 0.1%). The mean salmonella rate in diagnostic examinations of domestic animals was 5.77% (tab. 2). Cattle and chicken showed salmonella rates at the level of the mean rate, whereas pig, sheep, goats and equines showed much lower levels. On the other hand "other poultry" (9.5%) and especially chicks (13%) had higher levels of salmonella.(ABSTRACT TRUNCATED AT 250 WORDS)

Organochlorine pesticides, PCBs, trace elements and metals in western pond turtle eggs from Oregon

USGS Publications Warehouse

Henny, Charles J.; Beal, K.F.; Bury, R. Bruce; Goggans, R.

2003-01-01

With increased concern over the status of reptile populations globally, contaminant studies should be part of species evaluations. We analyzed eggs of western pond turtles from Fern Ridge Reservoir in western Oregon for 20 organochlorine (OC) pesticides or metabolites, 42 congener-specific polychlorinated biphenyls (PCBs), and 16 trace elements or metals. These eggs represent the first of this species analyzed. The OC pesticides and PCB residue concentrations in the western pond turtle eggs were generally low and similar to those found in eggs of snapping turtles from a remote site in Ontario, Canada. Western pond turtle eggs also contained mercury and chromium, which are metals of special concern. Although few reptilian eggs have been analyzed for metals, the 44.9 mug/g dry weight chromium in a western pond turtle egg in this study may be the highest reported in a reptilian egg. We found no significant difference in contaminant concentrations in eggs from nests in Oregon, where all turtle eggs failed to hatch compared to those where some eggs hatched. During this initial project, however, we were unable to assess fully the role of OCs, PCBs and other contaminants in the western pond turtle decline. Factors other than contaminants may be involved. In another study, snapping turtle eggs near the Great Lakes-St. Lawrence River basin were much more contaminated with evidence reported of effects on sex differentiation and reproductive endocrine function. Egg hatchability, the only reproductive parameter monitored, may not be the most sensitive endpoint. Other endpoints, including endocrine function, deformity rates, growth rates, and sex determination need study.

The epididymis as a target for male contraceptive development.

PubMed

Hinton, B T; Cooper, T G

2010-01-01

The epididymis is an excellent target for the development of a male contraceptive. This is because the process of sperm maturation occurs in this organ; spermatozoa become motile and are able to recognise and fertilise an egg once they have traversed the epididymal duct. However, a number of attempts to interfere in sperm maturation and epididymal function or both have not been successful. The use of transgenic animals has proved useful in identifying a few epididymal targets but has yet to open the doors for drug development. Continuous focus on identifying additional epididymal targets and sperm-specific and epididymal-specific drugs is key to bringing a male contraceptive acting on the epididymis to the public.

Effects of varying food and density on reproduction in Diaptomus clavipes Schacht

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooney, J.D.; Gehrs, C.W.; Bunting, D.L. II

1978-05-01

Experiments were conducted to determine the effects of varying food and density on the egg production of the calanoid copepod, Diaptomus clavipes Schacht. These experiments were performed at both the population and organismic level. An attempt was also made to evaluate the feasibility of using a flow-through system to study the effects of various environmental factors on egg production in copepods. It was found that food supply was an important factor determining rate of clutch production, number of eggs per clutch, and size of individual eggs. As food supply decreased, both the rate of clutch production and the number ofmore » eggs per clutch decreased, but the size of individual eggs increased. During periods of extreme food shortage, not only did egg production cease, but also the production of spermatophores by males. When starved females were placed under optimum feeding conditions, they produced eggs within a few days and were producing maximally within two weeks. Egg production in the flow-through system was reduced, due primarily to food shortage. The trout chow solution which was used as food was inadequate because it was not directly utilized by the copepods.« less

Autonomic reactivity during viewing of an unpleasant film.

PubMed

Baldaro, B; Mazzetti, M; Codispoti, M; Tuozzi, G; Bolzani, R; Trombini, G

2001-12-01

The effect of an aversive, high-arousing film on heart rate, respiratory sinus arrhythmia, and electrogastrographic activity (EGG) was investigated. Previous studies have indicated a larger heart-rate deceleration for visual stimuli depicting surgery or blood compared to neutral content, and this phenomenon is similar to the bradycardia observed in animals in response to fear. The heart-rate deceleration is clearly parasympathetically driven, and it is considered a general index of attention. An accurate index of cardiac vagal tone can be obtained by means of quantification of the amplitude of respiratory sinus arrhythmia. The relationship between cardiac vagal tone and EGG is complex, but animal research has shown that suppressing vagal activity dampens gastric motility. We have investigated whether a movie depicting surgery is associated with greater heart-rate deceleration, larger increase in respiratory sinus arrhythmia, and greater increase in EGG activity compared to a neutral movie. In addition, if both respiratory sinus arrhythmia and EGG are indices of vagal tone, a positive correlation between these physiological responses was expected. Analysis indicated an effect of the surgery movie on heart rate and respiratory sinus arrhythmia, but not on EGG activity. Moreover, the expected correlation was not found. Implications for future studies are discussed.

Tick vitellogenin receptor reveals critical role in oocyte development and transovarial transmission of Babesia parasite.

PubMed

Boldbaatar, Damdinsuren; Battsetseg, Badgar; Matsuo, Tomohide; Hatta, Takeshi; Umemiya-Shirafuji, Rika; Xuan, Xuenan; Fujisaki, Kozo

2008-08-01

A cDNA encoding the vitellogenin receptor of the ixodid tick, Haemaphysalis longicornis Neumann (HlVgR) was cloned and characterized. The full-length cDNA is 5631 bp, including an intact ORF encoding an expected protein with 1782 amino acids. The deduced amino acid sequence of the HlVgR cDNA revealed two ligand-binding domains with four class A cysteine-rich repeats in the first domain and eight in the second domain similar to those of insect VgRs. The immunoblot analysis detected approximately 197 kDa protein in both tick ovary and egg. The developmental expression profile demonstrated that HlVgR mRNA exists throughout the ovarian development, and the transcriptional level is especially high in the previtellogenic period. Immuno electron microscopy analysis demonstrated that the localization of HlVgR is detected on the external surface of oocyte plasma membrane. RNAi showed that eggs of HlVgR dsRNA-injected adult ticks had not developed into fully mature oocytes and laid abnormal eggs. The Babesia parasite DNA was not detected in the eggs of HlVgR dsRNA-injected tick that fed on Babesia gibsoni infected dog, whereas it was detected in the eggs of PBS-injected ticks and noninjected ticks. Expression of HlVgR was increased by the vitellogenic hormone 20-hydroxyecdysone. These results indicate that HlVgR, which is produced by the developing oocytes, is essential for Vg uptake, egg development in the H. longicornis tick, and transovarial transmission of Babesia parasites.

Use of sodium dodecyl sulfate pretreatment and 2-stage curing for improved quality of salted duck eggs.

PubMed

Lian, Zixuan; Qiao, Longshan; Zhu, Guanghong; Deng, Yun; Qian, Bingjun; Yue, Jin; Zhao, Yanyun

2014-03-01

The effects of use of sodium dodecyl sulfate (SDS) pretreatment and 2-stage curing on the microbial, physicochemical, and microstructural qualities of salted duck eggs were studied. After pretreatment in 0.5% (w/v) SDS solution at room conditions for 15 min, no discolorations were observed and no microorganisms were detected on the egg shells. In the 2-stage curing process, 25% (w/v) and 30% (w/v) saline solutions were evaluated in the 1st step (Stage I, approximately 18 d), whereas 4% (w/v) saline solution was applied in the 2nd step (Stage II, approximately 15 d). Along with increased curing time, water content decreased and NaCl content increased in the egg yolks from approximately 0.40% to 0.86%, whereas the water content of egg albumen remained at approximately 85% during the 2-stage curing. More importantly, the NaCl content of albumen maintained at approximately 4.0% at Stage II curing. Yolk index as a sign of maturity for salted duck eggs reached 1 at the end of Stage I (18 d) and retained the same value during Stage II curing regardless of the NaCl concentration in the Stage I saline solution. Oil exudation in egg yolks increased as the time of curing increased. As seen from scanning electron microscopy, oil was released from yolk granules. This study indicated that SDS pretreatment is effective to reduce microbial load on the shells of fresh duck eggs and the 2-stage curing can improve physicochemical qualities of the salted duck eggs and shortened curing time to about 7 to 17 d as compared to the traditional 1-step curing method. Spoiled saline solution and uneven distribution of salt are the 2 major problems in producing salted duck eggs. Sodium dodecyl sulfate (SDS) pretreatment and 2-stage curing process have shown effective to solve these problems, respectively. The SDS pretreatment was able to remove microorganisms and soil from the surface of fresh egg shells, thus preventing the spoilage of the saline solution. The 2-stage curing process successfully controlled the NaCl content of egg albumen and yolk in the final product, and shortened the curing time compared to the traditional 1-step curing method. © 2014 Institute of Food Technologists®

Intraspecific variation in body size and the rate of reproduction in female insects - adaptive allometry or biophysical constraint?

PubMed

Berger, David; Olofsson, Martin; Friberg, Magne; Karlsson, Bengt; Wiklund, Christer; Gotthard, Karl

2012-11-01

1. A high rate of reproduction may be costly if ecological factors limit immediate reproductive output as a fast metabolism compromises own future survival. Individuals with more reserves need more time and opportunity to realize their reproductive potential. Theory therefore predicts that the reproductive rate, defined as the investment in early reproduction in proportion to total potential, should decrease with body size within species. 2. However, metabolic constraints on body size- and temperature-dependent biological rates may impede biophysical adaptation. Furthermore, the sequential manner resources that are allocated to somatic vs. reproductive tissue during ontogeny may, when juveniles develop in unpredictable environments, further contribute to non-adaptive variation in adult reproductive rates. 3. With a model on female egg laying in insects, we demonstrate how variation in body reserves is predicted to affect reproductive rate under different ecological scenarios. Small females always have higher reproductive rates but shorter lifespans. However, incorporation of female host selectivity leads to more similar reproductive rates among female size classes, and oviposition behaviour is predicted to co-evolve with reproductive rate, resulting in small females being more selective in their choice and gaining relatively more from it. 4. We fed simulations with data on the butterfly Pararge aegeria to compare model predictions with reproductive rates of wild butterflies. However, simulated reproductive allometry was a poor predictor of that observed. Instead, reproductive rates were better explained as a product of metabolic constraints on rates of egg maturation, and an empirically derived positive allometry between reproductive potential and size. However, fitness is insensitive to moderate deviations in reproductive rate when oviposition behaviour is allowed to co-evolve in the simulations, suggesting that behavioural compensation may mitigate putative metabolic and developmental constraints. 5. More work is needed to understand how physiology and development together with compensatory behaviours interact in shaping reproductive allometry. Empirical studies should evaluate adaptive hypotheses against proper null hypotheses, including prediction from metabolic theory, preferentially by studying reproductive physiology in combination with behaviour. Conversely, inferences of constraint explanations on reproductive rates must take into consideration that adaptive scenarios may predict similar allometric exponents. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

Time-limited environments affect the evolution of egg-body size allometry.

PubMed

Eckerström-Liedholm, Simon; Sowersby, Will; Gonzalez-Voyer, Alejandro; Rogell, Björn

2017-07-01

Initial offspring size is a fundamental component of absolute growth rate, where large offspring will reach a given adult body size faster than smaller offspring. Yet, our knowledge regarding the coevolution between offspring and adult size is limited. In time-constrained environments, organisms need to reproduce at a high rate and reach a reproductive size quickly. To rapidly attain a large adult body size, we hypothesize that, in seasonal habitats, large species are bound to having a large initial size, and consequently, the evolution of egg size will be tightly matched to that of body size, compared to less time-limited systems. We tested this hypothesis in killifishes, and found a significantly steeper allometric relationship between egg and body sizes in annual, compared to nonannual species. We also found higher rates of evolution of egg and body size in annual compared to nonannual species. Our results suggest that time-constrained environments impose strong selection on rapidly reaching a species-specific body size, and reproduce at a high rate, which in turn imposes constraints on the evolution of egg sizes. In combination, these distinct selection pressures result in different relationships between egg and body size among species in time-constrained versus permanent habitats. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Embryonic and larval development and early behavior in grass carp, Ctenopharyngodon idella: implications for recruitment in rivers

USGS Publications Warehouse

George, Amy E.; Chapman, Duane C.

2015-01-01

With recent findings of grass carp Ctenopharyngodon idella in tributaries of the Great Lakes, information on developmental rate and larval behavior is critical to efforts to assess the potential for establishment within the tributaries of that region. In laboratory experiments, grass carp were spawned and eggs and larvae reared at two temperature treatments, one "cold" and one "warm", and tracked for developmental rate, egg size, and behavior. Developmental rate was quantified using Yi's (1988) developmental stages and the cumulative thermal units method. Grass carp had a thermal minimum of 13.5°C for embryonic stages and 13.3°C for larval stages. Egg size was related to temperature and maternal size, with the largest eggs coming from the largest females, and eggs were generally larger in warmer treatments. Young grass carp larvae exhibited upward and downward swimming interspersed with long periods of lying on the bottom. Swimming capacity increased with ontogeny, and larvae were capable of horizontal swimming and position holding with gas bladder emergence. Developmental rates, behavior, and egg attributes can be used in combination with physical parameters of a river to assess the risk that grass carp are capable of reproduction and recruitment in rivers.

[Effect of Parasep® feces centrifuge tube method on detecting schistosome eggs].

PubMed

Ma, Nian; Zhang, Hua-ming; Liu, Xiong; Xiao, Chuan-yun; Wen, Xiao-hong; Li, Xia; Dong, Li-chun; Cui, Cai-xia; Tu, Zu-wu

2014-08-01

To evaluate the effect of the Parasep® feces centrifuge tube method on detecting schistosome eggs. A total of 803 residents aged from 6-65 years were selected in 2 schistosomiasis endemic villages, Jiangling County, Hubei Province, and their stool samples were collected and detected parallelly by the Kato-Katz technique, nylon silk egg hatching method, and Parasep® feces centrifuge tube method at the same time. Among the 803 people, 15 cases were found of schistosome egg positive, and the positive rate was 1.87%. The positive rates of the Kato-Katz technique, nylon silk egg hatching method, and Parasep® feces centrifuge tube method were 0.75%, 1.49% and 1.12%, respectively. The schistosome eggs got with the Parasep® feces centrifuge tube method were clear and easy to identify. In low endemic areas of schistosomiasis, the Parasep® feces centrifuge tube method can be used as schistosomiasis japonica etiology diagnosis method.

Comparison of Kato-Katz thick-smear and McMaster egg counting method for the assessment of drug efficacy against soil-transmitted helminthiasis in school children in Jimma Town, Ethiopia.

PubMed

Bekana, Teshome; Mekonnen, Zeleke; Zeynudin, Ahmed; Ayana, Mio; Getachew, Mestawet; Vercruysse, Jozef; Levecke, Bruno

2015-10-01

There is a paucity of studies that compare efficacy of drugs obtained by different diagnostic methods. We compared the efficacy of a single oral dose albendazole (400 mg), measured as egg reduction rate, against soil-transmitted helminth infections in 210 school children (Jimma Town, Ethiopia) using both Kato-Katz thick smear and McMaster egg counting method. Our results indicate that differences in sensitivity and faecal egg counts did not imply a significant difference in egg reduction rate estimates. The choice of a diagnostic method to assess drug efficacy should not be based on sensitivity and faecal egg counts only. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

9 CFR 592.510 - Basetime rate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Basetime rate. 592.510 Section 592.510 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.510 Basetime rate. (a) For each...

9 CFR 592.510 - Base time rate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Base time rate. 592.510 Section 592.510 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.510 Base time rate. The...

9 CFR 592.530 - Holiday rate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Holiday rate. 592.530 Section 592.530 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.530 Holiday rate. When an official...

9 CFR 592.520 - Overtime rate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Overtime rate. 592.520 Section 592.520 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.520 Overtime rate. When operations in...

Effect of strain of layer and age at photostimulation on egg production, egg quality, and bone strength.

PubMed

Silversides, F G; Korver, D R; Budgell, K L

2006-07-01

Bone strength in layers is a concern for economic reasons and animal welfare concerns. Bone characteristics were investigated in 3 strains of hens: Babcock B-300, a small-bodied commercial white-egg layer; ISA-Brown, a commercial brown-egg layer; and an unselected Brown Leghorn line (BL). After being reared together in a single pen with 8 h of light per day, hens were caged with 14 h of light per day. Half of the hens were caged at 18 wk of age and the other half at 20 wk of age, resulting in a 2-wk difference in the age at photostimulation. Body weights, egg production, feed efficiency, and egg quality were measured throughout production. At 15, 25, 50, and 74 wk of age, hens were euthanized for sampling of the radius and the humerus. Breaking strength of the radius and humerus was measured, and the area and density of trabecular (largely medullary bone) and cortical bone were measured using quantitative computed tomography. Egg production and feed conversion of ISA-Brown hens was as good as or better than that of Babcock B-300 hens, and both commercial strains had higher production than the BL. Photostimulation late delayed sexual maturity and improved albumen and shell characteristics but had only minor effects on egg production and did not affect the yolk weight. The delayed photostimulation resulting from caging 2 wk later affected the radius by increasing the area of the trabecular space at 50 wk of age and the density of the bone in the trabecular space at 74 wk of age. Breaking strength of the humerus at 25 wk of age was greater for the birds that were photostimulated late but was not different later in the trial. The humerus, but not the radius, of the BL had a greater breaking strength than that of the commercial strains, suggesting that selection has decreased humeral breaking strength.

Egg positive rate of Enterobius vermicularis among preschool children in Cheongju, Chungcheongbuk-do, Korea

PubMed Central

Kang, Seokha; Jeon, Hyeong Kyu; Eom, Keeseon S.

2006-01-01

In an attempt to determine the prevalence of pinworm infection, the egg positive rate of Enterobius vermicularis was examined using the adhesive cello-tape anal swab method in 1,512 preschool children sampled from a total of 20 kindergartens in Cheongju city, in November to December of 2004 (951 children from 13 kindergartens) and September to October of 2005 (561 from 7 kindergartens). The overall egg positive rate was found to be 7.9% (119/1,512); 9.3% (73/784) for boys and 6.3% (46/728) for girls, respectively. The 5-year age group evidenced the highest egg positive rate (10.9%, 47/430) among the examined age groups. As compared to those reported from previous works (ranged from 9.2 to 26.1%), the prevalence of E. vermicularis in the Cheongju city area is relatively low. PMID:16969064

Water vapor permeability of the rigid-shelled gecko egg.

PubMed

Andrews, Robin M

2012-07-01

The vast majority of squamate reptiles (lizards and snakes) produce parchment-shelled eggs that absorb water during incubation, and thus increase in mass, volume, and surface area. In contrast, females from a single monophyletic lineage of gekkotan lizards produce rigid-shelled eggs. These eggs are functionally comparable to those of birds, that is, at oviposition, eggs contain all the water needed for development, and their mass decreases during incubation via the diffusion of water vapor through the shell. I determined patterns of water loss and shell permeability to water vapor from oviposition to hatching for the rigid-shelled eggs of the gekkonid Chrondrodactylus turneri and compared permeability of C. turneri eggs to those of birds and other squamates. Chrondrodactylus turneri eggs incubated at 28.5°C and 40% relative humidity (RH) decreased in mass by 14% over the course of a 68-day incubation period. The rate of water loss varied during incubation; egg mass decreased rapidly during the first 8 days of incubation, declined at a low constant rate during the next 35 days, and then decreased rapidly during the final 25 days of incubation. Overall permeability was 0.17 mg/day/kPa/cm(2) . Percent water loss of rigid-shelled gecko eggs during incubation is similar to that exhibited by birds, but water vapor permeability is about one-third that of bird eggs and several orders of magnitude lower than that of parchment-shelled squamate eggs. In general, the water economy of their eggs may be associated with the adaptive radiation of the rigid-shelled sphaerodactylid, phyllodactylid, and gekkonid geckos. © 2012 WILEY PERIODICALS, INC.

Resource allocation to reproduction in animals.

PubMed

Kooijman, Sebastiaan A L M; Lika, Konstadia

2014-11-01

The standard Dynamic Energy Budget (DEB) model assumes that a fraction κ of mobilised reserve is allocated to somatic maintenance plus growth, while the rest is allocated to maturity maintenance plus maturation (in embryos and juveniles) or reproduction (in adults). All DEB parameters have been estimated for 276 animal species from most large phyla and all chordate classes. The goodness of fit is generally excellent. We compared the estimated values of κ with those that would maximise reproduction in fully grown adults with abundant food. Only 13% of these species show a reproduction rate close to the maximum possible (assuming that κ can be controlled), another 4% have κ lower than the optimal value, and 83% have κ higher than the optimal value. Strong empirical support hence exists for the conclusion that reproduction is generally not maximised. We also compared the parameters of the wild chicken with those of races selected for meat and egg production and found that the latter indeed maximise reproduction in terms of κ, while surface-specific assimilation was not affected by selection. We suggest that small values of κ relate to the down-regulation of maximum body size, and large values to the down-regulation of reproduction. We briefly discuss the ecological context for these findings. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

[Monitoring and SWOT analysis of Ascaris eggs pollution in soil of rural China].

PubMed

Zhu, Hui-hui; Zhou, Chang-hai; Zang, Wei; Zhang, Xue-qiang; Chen, Ying-dan

2014-06-01

To understand the status of Ascaris eggs pollution in soil at national monitoring spots of soil-transmitted nematodiasis, so as to provide the evidence for making countermeasures and evaluating the control effect. Ten households were selected from each of the 22 national monitoring spots annually according to the National Surveillance Program of Soil-Transmitted Nematodiasis (Trial), and the soil samples from vegetable gardens, toilet periphery, courtyards and kitchens were collected and examined by using the modified floatation test with saturated sodium nitrate. Fertilized or unfertilized eggs as well as live or dead fertilized eggs were discriminated and identified. In addition, a SWOT analysis of monitoring of Ascaris eggs pollution in the soil of rural China was carried out. A total of 1 090 households were monitored in 22 monitoring spots from 2006 to 2010. The total detection rate of Ascaris eggs in the soil was 30.73%, and the detection rates of fertilized, unfertilized and live fertilized eggs were 13.21%, 26.42% and 20.28%, respectively. The total detection rates of Ascaris eggs in the vegetable garden, toilet periphery, courtyard and kitchen were 16.51%, 13.49%, 14.22% and 10.73% respectively. The SWOT analysis demonstrated that the monitoring work had both advantages and disadvantages, and was faced with opportunities as well as threats. The pollution status of Ascaris eggs in the soil is still quite severe at some national monitoring spots, and the counter-measures such as implementing hazard-free treatment of stool, improving water supply and sanitation and reforming environment should be taken to protect people from being infected.

Research on Captive Broodstock Programs for Pacific Salmon, 2003-2004 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berejikian, Barry A.; Athos, Jaime I.; Dittman, Andrew H.

The success of captive broodstock programs depends on high in-culture survival, appropriate development of the reproductive system, and the behavior and survival of cultured salmon after release, either as adults or juveniles. Continuing captive broodstock research designed to improve technology is being conducted to cover all major life history stages of Pacific salmon. We were able to develop an analytical method for optimizing the detection of spawning events in Chinook salmon using EMG signals. The method developed essentially captured the consistently greater frequency of higher EMG values associated with females cover digging immediately following spawning. However, females implanted with EMGmore » tags retained the majority of their eggs, which significantly reduced their reproductive success compared to non-tagged females. Future work will include increased sample sizes, and modified tagging methods to reduce negative effects on reproductive success. Upper Columbia River sockeye salmon exposed to the odorants PEA, L-threonine, Larginine and L-glutamate were able to learn and remember these odorants as maturing adults up to 2.5 years after exposure. These results suggest that the alevin and smolt stages are both important developmental periods for successful olfactory imprinting. Furthermore, the period of time that fish are exposed to imprinting odors may be important for successful imprinting. Experimental fish exposed to imprinting odors as smolts for six or one weeks successfully imprinted to these odors but imprinting could not be demonstrated in smolts exposed to odors for only one day. A 2-3 C reduction in seawater rearing temperature during the fall and winter prior to final maturation had little effect on reproductive development of spring Chinook salmon. Body size at spawning and total ovary mass were similar between temperature treatments. The percentage of fertilized eggs was significantly higher for females exposed to the ambient temperature compared to those exposed to the chilled temperature. However, the percentage of embryos surviving to the eye-stage, total fecundity, and mean egg mass did not differ between treatments. This work is being continued with larger samples sizes and increased duration of temperature exposure. Exercise during the months prior to final maturation had no detectable effects on fertilization success or embryo viability in Redfish Lake Sockeye. Problems with highly variable or low eyed-embryo survival are most likely due to problems with fertilization. Synchronizing spawn timing between males and females may improve gamete fertility, perhaps by making oocyte maturation and ovulation more readily detectable and synchronous within the individual. Improvements in milt production (using GnRHa) and fertilization protocols have apparently increased fertilization success in Redfish Lake sockeye over previous years. Broodstock treatment with azithromycin immediately prior to spawning can protect against acute challenge with R. salmoninarum. Among fish challenged with 10,000 virulent R. salmoninarum cells per fish, progeny of broodstock treated with azithromycin exhibited significantly greater survival than progeny of sham-treated broodstock. Work on the efficacy of antibiotic treatment and vaccination against BKD before and after smoltification in offspring chinook salmon captive broodstocks is ongoing. To date, the long-term study of inbreeding indicates that the potential for anadromous Chinook salmon to respond rapidly to close inbreeding, with adverse consequences for marine survival and, possibly, growth. The effects of inbreeding expressed during early life history do not reveal significant effects. Overall, the results would support recommendations for initiating artificially propagated populations with sufficient, outbred broodstock and implementing carefully monitored breeding practices to minimize rates of inbreeding during a program's duration.« less

Assessing the potential for egg chemoattractants to mediate sexual selection in a broadcast spawning marine invertebrate

PubMed Central

Evans, Jonathan P.; Garcia-Gonzalez, Francisco; Almbro, Maria; Robinson, Oscar; Fitzpatrick, John L.

2012-01-01

In numerous species, egg chemoattractants play a critical role in guiding sperm towards unfertilized eggs (sperm chemotaxis). Until now, the known functions of sperm chemotaxis include increasing the effective target size of eggs, thereby promoting sperm–egg encounters, and facilitating species recognition. Here, we report that in the broadcast spawning mussel, Mytilus galloprovincialis, egg chemoattractants may play an unforeseen role in sexual selection by enabling sperm to effectively ‘choose’ between the eggs of different conspecific females. In an initial experiment, we confirmed that sperm chemotaxis occurs in M. galloprovincialis by showing that sperm are attracted towards unfertilized eggs when given the choice of eggs or no eggs in a dichotomous chamber. We then conducted two cross-classified mating experiments, each comprising the same individual males and females crossed in identical male × female combinations, but under experimental conditions that offered sperm ‘no-choice’ (each fertilization trial took place in a Petri dish and involved a single male and female) or a ‘choice’ of a female's eggs (sperm were placed in the centre of a dichotomous choice chamber and allowed to choose eggs from different females). We show that male-by-female interactions characterized fertilization rates in both experiments, and that there was remarkable consistency between patterns of sperm migration in the egg-choice experiment and fertilization rates in the no-choice experiment. Thus, sperm appear to exploit chemical cues to preferentially swim towards eggs with which they are most compatible during direct sperm-to-egg encounters. These results reveal that sperm differentially select eggs on the basis of chemical cues, thus exposing the potential for egg chemoattractants to mediate mate choice for genetically compatible partners. Given the prevalence of sperm chemotaxis across diverse taxa, our findings may have broad implications for sexual selection in other mating systems. PMID:22438495

Effect of Temperature on Biochemical Composition, Growth and Reproduction of the Ornamental Red Cherry Shrimp Neocaridina heteropoda heteropoda (Decapoda, Caridea)

PubMed Central

Tropea, Carolina; Stumpf, Liane; López Greco, Laura Susana

2015-01-01

The effect of water temperature on biochemical composition, growth and reproduction of the ornamental shrimp, Neocaridina heteropoda heteropoda, was investigated to determine the optimum temperature for its culture. The effect of embryo incubation temperature on the subsequent performance of juveniles was also evaluated. Ovigerous females and recently hatched juveniles (JI) were maintained during egg incubation and for a 90-day period, respectively, at three temperatures (24, 28 and 32°C). Incubation period increased with decreasing water temperature, but the number and size of JI were similar among treatments. At day 30 of the 90-day period, body weight and growth increment (GI) at 24°C were lower than those at 28 and 32°C. On subsequent days, GI at 24°C exceeded that at 28 and 32°C, leading to a similar body weight among treatments. These results suggest growth was delayed at 24°C, but only for 30 days after hatching. The lipid concentration tended to be lowest, intermediate and highest at 28, 32 and 24°C, respectively, possibly as a consequence of the metabolic processes involved in growth and ovarian maturation. Protein and glycogen concentrations were similar among treatments. Both the growth trajectory and biochemical composition of shrimps were affected by the temperature experienced during the 90-day growth period independently of the embryo incubation temperature. During the growth period, shrimps reached sexual maturity and mated, with the highest proportion of ovigerous females occurring at 28°C. All the females that matured and mated at 32°C lost their eggs, indicating a potentially stressful effect of high temperature on ovarian maturation. Based on high survival and good growth performance of shrimps at the three temperatures tested over the 90-day period it is concluded that N. heteropoda heteropoda is tolerant to a wide range of water temperatures, with 28°C being the optimum temperature for its culture. PMID:25768918

Development of the follicle complex and oocyte staging in red drum, Sciaenops ocellatus Linnaeus, 1776 (Perciformes, Sciaenidae).

PubMed

Grier, Harry J

2012-08-01

Pelagic egg development in red drum, Sciaenops ocellatus, is described using tiered staging. Based on mitosis and meiosis, there are five periods: Mitosis of Oogonia, Active Meiosis I, Arrested Meiosis I, Active Meiosis II, and Arrested Meiosis II. The Periods are divided into six stages: Mitotic Division of Oogonia, Chromatin Nucleolus, Primary Growth, Secondary Growth, Oocyte Maturation and Ovulation. The Chromatin Nucleolus Stage is divided into four steps: Leptotene, Zygotene, Pachytene, and Early Diplotene. Oocytes in the last step possess one nucleolus, dispersed chromatin with forming lampbrush chromosomes and lack basophilic ooplasm. The Primary Growth Stage, characterized by basophilic ooplasm and absence of yolk in oocytes, is divided into five steps: One-Nucleolus, Multiple Nucleoli, Perinucleolar, Oil Droplets, and Cortical Alveolar. During primary growth, the Balbiani body develops from nuage, enlarges and disperses throughout the ooplasm as both endoplasmic reticulum and Golgi develop within it. Secondary growth or vitellogenesis has three steps: Early Secondary Growth, Late Secondary Growth and Full-Grown. The Oocyte Maturation Stage, including ooplasmic and germinal vesicle maturation, has four steps: Eccentric Germinal Vesicle, Germinal Vesicle Migration, Germinal Vesicle Breakdown and Resumption of Meiosis when complete yolk hydration occurs. The period is Arrested Meiosis II. When folliculogenesis is completed, the ovarian follicle, an oocyte and encompassing follicle cells, is surrounded by a basement membrane and developing theca, all forming a follicle complex. After ovulation, a newly defined postovulatory follicle complex remains attached to the germinal epithelium. It is composed of a basement membrane that separates the postovulatory follicle from the postovulatory theca. Arrested Meiosis I encompasses primary and secondary growth (vitellogenesis) and includes most of oocyte maturation until the resumption of meiosis (Active Meiosis II). The last stage, Ovulation, is the emergence of the oocyte from the follicle when it becomes an egg or ovum. Copyright © 2012 Wiley Periodicals, Inc.

Epidemiology of Toxocara vitulorum in cattle around Bursa, Turkey.

PubMed

Akyol, C V

1993-03-01

The prevalence of Toxocara vitulorum in cattle around Bursa, Turkey, was surveyed by faecal examination of eggs. The average infection rate among 11 towns was 5.1% in calves younger than 6-months-old, and 2.2% in all ages of animals. T. vitulorum was found to be prevalent in two different areas of Bursa. Third stage larvae were found in one milk sample and therefore galactogenic transmission was suggested. Experimental incubation of eggs showed that the optimum temperature for development was 20 to 30 degrees C and eggs could survive under low temperature, indicating that grazing in the contaminated pasture may accelerate the transmission of eggs to cows. Mode of farming, therefore, affects the infection rate of T. vitulorum and may explain the difference in the rate between the two areas.

Identification of the Key Weather Factors Affecting Overwintering Success of Apolygus lucorum Eggs in Dead Host Tree Branches

PubMed Central

Pan, Hongsheng; Liu, Bing; Lu, Yanhui; Desneux, Nicolas

2014-01-01

Understanding the effects of weather on insect population dynamics is crucial to simulate and forecast pest outbreaks, which is becoming increasingly important with the effects of climate change. The mirid bug Apolygus lucorum is an important pest on cotton, fruit trees and other crops in China, and primarily lays its eggs on dead parts of tree branches in the fall for subsequent overwintering. As such, the eggs that hatch the following spring are most strongly affected by ambient weather factors, rather than by host plant biology. In this study, we investigated the effects of three major weather factors: temperature, relative humidity and rainfall, on the hatching rate of A. lucorum eggs overwintering on dead branches of Chinese date tree (Ziziphus jujuba). Under laboratory conditions, rainfall (simulated via soaking) was necessary for the hatching of overwintering A. lucorum eggs. In the absence of rainfall (unsoaked branches), very few nymphs successfully emerged under any of the tested combinations of temperature and relative humidity. In contrast, following simulated rainfall, the hatching rate of the overwintering eggs increased dramatically. Hatching rate and developmental rate were positively correlated with relative humidity and temperature, respectively. Under field conditions, the abundance of nymphs derived from overwintering eggs was positively correlated with rainfall amount during the spring seasons of 2009–2013, while the same was not true for temperature and relative humidity. Overall, our findings indicate that rainfall is the most important factor affecting the hatching rate of overwintering A. lucorum eggs on dead plant parts and nymph population levels during the spring season. It provides the basic information for precisely forecasting the emergence of A. lucorum and subsequently timely managing its population in spring, which will make it possible to regional control of this insect pest widely occurring in multiple crops in summer. PMID:24705353

Identification of the key weather factors affecting overwintering success of Apolygus lucorum eggs in dead host tree branches.

PubMed

Pan, Hongsheng; Liu, Bing; Lu, Yanhui; Desneux, Nicolas

2014-01-01

Understanding the effects of weather on insect population dynamics is crucial to simulate and forecast pest outbreaks, which is becoming increasingly important with the effects of climate change. The mirid bug Apolygus lucorum is an important pest on cotton, fruit trees and other crops in China, and primarily lays its eggs on dead parts of tree branches in the fall for subsequent overwintering. As such, the eggs that hatch the following spring are most strongly affected by ambient weather factors, rather than by host plant biology. In this study, we investigated the effects of three major weather factors: temperature, relative humidity and rainfall, on the hatching rate of A. lucorum eggs overwintering on dead branches of Chinese date tree (Ziziphus jujuba). Under laboratory conditions, rainfall (simulated via soaking) was necessary for the hatching of overwintering A. lucorum eggs. In the absence of rainfall (unsoaked branches), very few nymphs successfully emerged under any of the tested combinations of temperature and relative humidity. In contrast, following simulated rainfall, the hatching rate of the overwintering eggs increased dramatically. Hatching rate and developmental rate were positively correlated with relative humidity and temperature, respectively. Under field conditions, the abundance of nymphs derived from overwintering eggs was positively correlated with rainfall amount during the spring seasons of 2009-2013, while the same was not true for temperature and relative humidity. Overall, our findings indicate that rainfall is the most important factor affecting the hatching rate of overwintering A. lucorum eggs on dead plant parts and nymph population levels during the spring season. It provides the basic information for precisely forecasting the emergence of A. lucorum and subsequently timely managing its population in spring, which will make it possible to regional control of this insect pest widely occurring in multiple crops in summer.

Assessment of Trichogramma japonicum and T. chilonis as Potential Biological Control Agents of Yellow Stem Borer in Rice

PubMed Central

Tang, Rui; Babendreier, Dirk; Zhang, Feng; Kang, Min; Song, Kai; Hou, Mao-Lin

2017-01-01

Two species of Trichogramma wasps were assessed for their effectiveness against yellow stem borer Scirpophaga incertulas. A laboratory cage test with T. japonicum and T. chilonis showed that both species parasitized yellow stem borer egg masses at 60.0% ± 9.13% and 40.7% ± 7.11%, respectively, with egg parasitism rates of 15.8% ± 22.2% for T. japonicum and 2.8% ± 5.0% for T. chilonis. Once the host eggs were parasitized, emergence rates were high for both species (95.7% ± 0.12% for T. japonicum and 100% for T. chilonis). In paddy field trials, the two Trichogramma species were released at three densities (50,000/ha, 100,000/ha and 200,000/ha) in Southwestern China. Egg mass parasitism was 9% ± 7.7% for T. japonicum and 15% ± 14.1% for T. chilonis, and again only a relatively small fraction of eggs was successfully parasitized. No clear conclusion could be drawn on the most efficient release rate as no significant differences were found among the three release rates. A comparison of field-collected T. japonicum with T. japonicum and T. chilonis mass reared on Corcyra cephalonica showed significantly larger body size and ovipositor length in field-collected wasps, suggesting potentially higher effectiveness on yellow stem borer eggs after at least one generation on the target host. Factors contributing to the low field parasitism rates are discussed. PMID:28208706

Differences in Flight Activity of Coleomegilla maculata and Hippodamia convergens (Coleoptera: Coccinellidae) Following Emergence, Mating, and Reproduction.

PubMed

Abdel-Wahab, Ahmed H; Michaud, J P; Bayoumy, Mohamed H; Awadalla, Samir S; El-Gendy, Mohamed

2017-12-08

The flight activity of Coleomegilla maculata DeGeer and Hippodamia convergens Guerin-Meneville (Coleoptera: Coccinellidae) was examined by observing tethered beetles in the laboratory. C. maculata were fed eggs of Ephestia kuehniella Zeller, as were larval H. convergens, whereas adult H. convergens were fed Melanaphis sacchari (Zehntner) to induce egg maturation; adults of both species received water and diluted honey. A spot of magnetic paint was applied to one elytrum of each beetle, which then adhered to a small neodymium magnet attached to a thread. Beetles were permitted 1 h flight opportunities daily for 3-d periods, first as virgins on their fifth day of adult life, secondly after mating, thirdly after females began oviposition, and fourthly after prey were withheld and egg maturation and oviposition ceased. Both species exhibited low flight activity as virgins, and whereas C. maculata females increased their activity after mating, H. convergens females did not. Flight activity in C. maculata did not change with onset of oviposition, whereas it increased in H. convergens males, but not females. In contrast, H. convergens females increased their flight activity after cessation of oviposition, whereas C. maculata females did not. Female flight activity when either virgin or mated correlated weakly with fecundity in C. maculata, but not in H. convergens. Species differences are discussed in the context of nutritional ecology; H. convergens usually enters diapause immediately following emergence, and is more dependent on aphids for reproduction, whereas C. maculata develops and reproduces on a wider range of foods and is not so constrained. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Life history and feeding biology of the deep-sea pycnogonid Nymphon hirtipes

NASA Astrophysics Data System (ADS)

Mercier, Annie; Baillon, Sandrine; Hamel, Jean-François

2015-12-01

Pycnogonids (sea spiders) are commonly collected at bathyal and abyssal depths all around the world; however, little is known about species from deep-water habitats. The present study explores the life history of Nymphon hirtipes collected in northeastern Newfoundland between 700 and 1450 m depth and monitored in mesocosms for over 2 years. The pycnogonids were found in association with octocorals, hydrozoans and sea anemones. Adult females developed mature oocytes between June and August. Paired mating followed by oviposition occurred between early July and mid-October. Up to three egg masses were brooded by each male. It took a maximum of 4 months for the propagules to hatch from the egg mass. Offspring developed from walking leg-bearing larvae to early juveniles over the next ~5 months before leaving the male's protection. Mating and oviposition coincided with the highest water temperatures of the annual cycle and dispersal of juveniles occurred in spring, when phytodetritus deposition was high and as ocean temperature rose markedly. All the females died after oviposition and the males ~9 months later, after juvenile dispersal. The sex ratio of mature individuals (~55-60 mm leg span) was 2 males for 3 females. Fecundity was estimated to be 184-288 eggs per adult female. Adults of N. hirtipes were seen feeding on hydrozoan polyps, small sea anemones (Stephanauge nexilis) and nudibranchs. Larvae and early juveniles did not feed while brooded by the male. Upon dispersal, their feeding apparatus became functional and they began feeding on hydrozoan polyps. After 13 months of growth post hatching, the juveniles reached ~21 mm leg span. Curve fitting estimated that ~7 years are required to reach the adult size of 55 mm leg span.

Maternal effects and larval survival of marbled sole Pseudopleuronectes yokohamae

NASA Astrophysics Data System (ADS)

Higashitani, Tomomi; Takatsu, Tetsuya; Nakaya, Mitsuhiro; Joh, Mikimasa; Takahashi, Toyomi

2007-07-01

Maternal effects of animals are the phenotypic influences of age, size, and condition of spawners on the survival and phenotypic traits of offspring. To clarify the maternal effects for marbled sole Pseudopleuronectes yokohamae, we investigated the effects of body size, nutrient condition, and growth history of adult females on egg size, larval size, and starvation tolerance, growth, and feeding ability of offspring. The fecundity of adult females was strongly dependent on body size. Path analysis revealed that the mother's total length positively affected mean egg diameter, meaning that large females spawned large eggs. In contrast, the relative growth rate of adult females negatively affected egg diameter. Egg diameters positively affected both notochord length and yolk sac volume of the larvae at hatching. Under starvation conditions, notochord length at hatching strongly and positively affected days of survival at 14 °C but not at 9 °C. Under adequate food conditions (1000 rotifers L - 1 ), the notochord length of larvae 5 days after hatching positively affected feeding rate, implying that large larvae have high feeding ability. In addition, the mean growth rate of larvae between 0 and 15 days increased with increasing egg diameter under homogenous food conditions, suggesting that larvae hatched from large eggs might have a growth advantage for at least to 15 days after hatching. In marbled sole, these relationships (i.e., mother's body size-egg size-larval size-larval resistance to starvation-larval feeding ability) may help explain recruitment variability.

Larval crowding accelerates C. elegans development and reduces lifespan.

PubMed

Ludewig, Andreas H; Gimond, Clotilde; Judkins, Joshua C; Thornton, Staci; Pulido, Dania C; Micikas, Robert J; Döring, Frank; Antebi, Adam; Braendle, Christian; Schroeder, Frank C

2017-04-01

Environmental conditions experienced during animal development are thought to have sustained impact on maturation and adult lifespan. Here we show that in the model organism C. elegans developmental rate and adult lifespan depend on larval population density, and that this effect is mediated by excreted small molecules. By using the time point of first egg laying as a marker for full maturity, we found that wildtype hermaphrodites raised under high density conditions developed significantly faster than animals raised in isolation. Population density-dependent acceleration of development (Pdda) was dramatically enhanced in fatty acid β-oxidation mutants that are defective in the biosynthesis of ascarosides, small-molecule signals that induce developmental diapause. In contrast, Pdda is abolished by synthetic ascarosides and steroidal ligands of the nuclear hormone receptor DAF-12. We show that neither ascarosides nor any known steroid hormones are required for Pdda and that another chemical signal mediates this phenotype, in part via the nuclear hormone receptor NHR-8. Our results demonstrate that C. elegans development is regulated by a push-pull mechanism, based on two antagonistic chemical signals: chemosensation of ascarosides slows down development, whereas population-density dependent accumulation of a different chemical signal accelerates development. We further show that the effects of high larval population density persist through adulthood, as C. elegans larvae raised at high densities exhibit significantly reduced adult lifespan and respond differently to exogenous chemical signals compared to larvae raised at low densities, independent of density during adulthood. Our results demonstrate how inter-organismal signaling during development regulates reproductive maturation and longevity.

Larval crowding accelerates C. elegans development and reduces lifespan

PubMed Central

Ludewig, Andreas H.; Gimond, Clotilde; Judkins, Joshua C.; Thornton, Staci; Pulido, Dania C.; Micikas, Robert J.; Döring, Frank; Antebi, Adam; Braendle, Christian; Schroeder, Frank C.

2017-01-01

Environmental conditions experienced during animal development are thought to have sustained impact on maturation and adult lifespan. Here we show that in the model organism C. elegans developmental rate and adult lifespan depend on larval population density, and that this effect is mediated by excreted small molecules. By using the time point of first egg laying as a marker for full maturity, we found that wildtype hermaphrodites raised under high density conditions developed significantly faster than animals raised in isolation. Population density-dependent acceleration of development (Pdda) was dramatically enhanced in fatty acid β-oxidation mutants that are defective in the biosynthesis of ascarosides, small-molecule signals that induce developmental diapause. In contrast, Pdda is abolished by synthetic ascarosides and steroidal ligands of the nuclear hormone receptor DAF-12. We show that neither ascarosides nor any known steroid hormones are required for Pdda and that another chemical signal mediates this phenotype, in part via the nuclear hormone receptor NHR-8. Our results demonstrate that C. elegans development is regulated by a push-pull mechanism, based on two antagonistic chemical signals: chemosensation of ascarosides slows down development, whereas population-density dependent accumulation of a different chemical signal accelerates development. We further show that the effects of high larval population density persist through adulthood, as C. elegans larvae raised at high densities exhibit significantly reduced adult lifespan and respond differently to exogenous chemical signals compared to larvae raised at low densities, independent of density during adulthood. Our results demonstrate how inter-organismal signaling during development regulates reproductive maturation and longevity. PMID:28394895

Localization and expression of peroxiredoxin II in the mouse ovary, oviduct, uterus, and preimplantation embryo.

PubMed

Wang, Shie; Huang, Weiquan; Shi, Hexiu; Lin, Cuiying; Xie, Meirong; Wang, Jianxin

2010-02-01

Peroxiredoxin (Prx) II belongs to a recently discovered family of peroxidases that play important roles in antioxidation and signal transduction. In this study, we aimed to study the localization and expression of Prx II in the mouse ovary, oviduct, and uterus, and preimplantation embryos. Immunohistochemical staining analysis showed that, in the ovary, Prx II was expressed in the oocyte cytoplasm of the primary follicle, the secondary follicle, and the premature follicle; Prx II was expressed in germinal vesicle-intact oocytes (GV oocytes) and metaphase II eggs (MII eggs), as well as at various stages in early embryos. Reverse transcription polymerase chain reaction (RT-PCR) results indicated that the Prx II mRNA was expressed at a high level in GV eggs, slightly lower levels in MII eggs, and had no detectable expression in four-cell embryos and early blastocysts. In the oviduct, Prx II was expressed in the epithelia, while in the uterus Prx II was mainly distributed in the endometrial stroma. Taken together, our results suggest that Prx II plays a key antioxidation role in the maturation of oocytes and development of early embryos, thus providing crucial experimental evidence for further exploring the function of Prx II in the development of oocytes and preimplantation embryos. 2009 Wiley-Liss, Inc.

Mechanical stimulation by osmotic and hydrostatic pressure activates Drosophila oocytes in vitro in a calcium-dependent manner

PubMed Central

Horner, Vanessa L.; Wolfner, Mariana F.

2008-01-01

Summary Embryogenesis in vertebrates and marine invertebrates begins when a mature oocyte is fertilized, resulting in a rise in intracellular calcium (Ca2+) that activates development. Insect eggs activate without fertilization via an unknown signal imparted to the egg during ovulation or egg laying. One hypothesis for the activating signal is that deformation of eggs as they pass through a tight orifice provides a mechanical stimulus to trigger activation. Ovulation could produce two forms of mechanical stimulus: external pressure resulting from the passage of oocytes from the ovary into the narrow oviducts, and osmotic pressure caused by hydration-induced swelling of the oocyte within the oviducts. Ovulation could also trigger activation by placing the oocyte in a new environment that contains an activating substance, such as a particular ion. Here, we provide the first evidence that Drosophila oocytes require Ca2+ for activation, and that activation can be triggered in vitro by mechanical stimuli, specifically osmotic and hydrostatic pressure. Our results suggest that activation in Drosophila is triggered by a mechanosensitive process that allows external Ca2+ to enter the oocyte and drive the events of activation. This will allow exploitation of Drosophila genetics to dissect molecular pathways involving Ca2+ and the activation of development. PMID:18304524

Influence of arginine-glycine-aspartic acid (RGD), integrins (alphaV and alpha5) and osteopontin on bovine sperm-egg binding, and fertilization in vitro.

PubMed

Gonçalves, R F; Wolinetz, C D; Killian, G J

2007-02-01

Osteopontin (OPN), a phosphoprotein containing an arginine-glycine-aspartic acid (RGD) sequence, has been identified in cow oviduct epithelium and fluid. To investigate the potential role OPN in fertilization, we evaluated the ability of RGD peptide (arginine-glycine-aspartic), RGE peptide (arginine-glycine-glutamic acid), integrins alphaV and alpha5 antibodies and OPN antibody to influence bovine in vitro sperm-egg binding and fertilization. Treatment of sperm or oocytes with the RGD peptide prior fertilization significantly decreased in vitro sperm-egg binding and fertilization compared to the non-treated controls or those treated with RGE peptide. Binding and fertilization were also significantly decreased when in vitro matured bovine oocytes or sperm were pre-incubated with integrins alphaV and alpha5 antibodies at concentration ranging from 5 to 20 microg/mL. Addition of a rabbit polyclonal IgG antibody against purified bovine milk OPN with sperm or/and oocytes decreased (P<0.05) fertilization compared to the in vitro-fertilized control. These data provided evidence that integrin ligands existed on bovine oocytes and spermatozoa that contained RGD recognition sequences, and that antibody to OPN, a protein that contains that RGD sequence, was capable of reducing sperm-egg binding and fertilization in vitro.

Insect eggs protected from high temperatures by limited homeothermy of plant leaves.

PubMed

Potter, Kristen; Davidowitz, Goggy; Woods, H Arthur

2009-11-01

Virtually all aspects of insect biology are affected by body temperature, and many taxa have evolved sophisticated temperature-control mechanisms. All insects, however, begin life as eggs and lack the ability to thermoregulate. Eggs laid on leaves experience a thermal environment, and thus a body temperature, that is strongly influenced by the leaves themselves. Because plants can maintain leaf temperatures that differ from ambient, e.g. by evapotranspiration, plant hosts may protect eggs from extreme ambient temperatures. We examined the degree to which leaves buffer ambient thermal variation and whether that buffering benefits leaf-associated insect eggs. In particular, we: (1) measured temperature variation at oviposition sites in the field, (2) manipulated temperatures in the laboratory to determine the effect of different thermal conditions on embryo development time and survival, and (3) tested embryonic metabolic rates over increasing temperatures. Our results show that Datura wrightii leaves buffer Manduca sexta eggs from fatally high ambient temperatures in the southwestern USA. Moreover, small differences in temperature profiles among leaves can cause large variation in egg metabolic rate and development time. Specifically, large leaves were hotter than small leaves during the day, reaching temperatures that are stressfully high for eggs. This study provides the first mechanistic demonstration of how this type of leaf-constructed thermal refuge interacts with egg physiology.

Ocular Manifestations of Mosquito-Transmitted Diseases.

PubMed

Karesh, James W; Mazzoli, Robert A; Heintz, Shannon K

2018-03-01

Of the 3,548 known mosquito species, about 100 transmit human diseases. Mosquitoes are distributed globally throughout tropical and temperate regions where standing water sources are available for egg laying and the maturation of larva. Female mosquitoes require blood meals for egg production. This is the main pathway for disease transmission. Mosquitoes carry several pathogenic organisms responsible for significant ocular pathology and vision loss including West Nile, Rift Valley, chikungunya, dengue viruses, various encephalitis viruses, malarial parasites, Francisella tularensis, microfilarial parasites, including Dirofilaria, Wuchereria, and Brugia spp., and human botfly larvae. Health care providers may not be familiar with many of these mosquito-transmitted diseases or their associated ocular findings delaying diagnosis, treatment, and recovery of visual function. This article aims to provide an overview of the ocular manifestations associated with mosquito-transmitted diseases.

Effects of in ovo exposure to 2,3,7,8-TCDD on F1 generation adult chickens (Gallus gallus).

PubMed

Alonso, K R; Peden-Adams, M M; Liu, J Y; Charbonneau, C; Henshel, D; Dickerson, R L

1998-01-01

White Leghorn chickens (Gallus gallus) were used as surrogate species for the resident wild turkeys found on the Times Beach, Missouri, Superfund site. Parental chickens were injected with concentrations of 2,3,7,8-TCDD which modeled soil concentrations before (200 ppb) and after remediation (1ppb)[1]. Offspring were followed through development to assess alterations in reproductive maturity through the use of a four-way breeding study. F1 adult females exposed to a maternal dose of 8.6 ng/day began egg production approximately two weeks later than did F1 control adult females. By week eight, however, egg production between groups was equivalent. No differences were observed in eggshell gland estrogen or progesterone receptor levels.

Biology of Fopius arisanus (Hymenoptera: Braconidae) in Two Species of Fruit Flies

PubMed Central

Groth, M. Z.; Loeck, A. E.; Nörnberg, S. D.; Bernardi, D.; Nava, D. E.

2016-01-01

Fopius arisanus (Sonan, 1932) (Hymenoptera: Braconidae) is an egg–larval parasitoid used in control programs of Bactrocera dorsalis (Hendel) and Ceratitis capitata (Wiedemann). In Brazil, C. capitata and Anastrepha fraterculus (Wiedemann) are considered the main tephritid pests of exotic and indigenous fruits. The objective of this study was to study the biology of F. arisanus in C. capitata and A. fraterculus. Eggs of the two fruit fly species were used to determine the parasitism rate, number of offspring, emergence rate, sex ratio, adult weight and longevity of male and female F. arisanus. These biological parameters were used to develop a fertility life table. We observed higher parasitism and emergence rates of adults, a shorter duration of the egg–adult period and a sex ratio biased to females when F. arisanus was reared in eggs of C. capitata than in those of A. fraterculus. However, adults of F. arisanus from eggs of A. fraterculus were heavier and had greater longevity than those obtained from C. capitata eggs. The fertility life table showed better biological and reproductive performance for F. arisanus reared in eggs of C. capitata, although eggs of A. fraterculus also provided positive values for population increase. PMID:27638954

Minimum size limits for yellow perch (Perca flavescens) in western Lake Erie

USGS Publications Warehouse

Hartman, Wilbur L.; Nepszy, Stephen J.; Scholl, Russell L.

1980-01-01

During the 1960's yellow perch (Perca flavescens) of Lake Erie supported a commercial fishery that produced an average annual catch of 23 million pounds, as well as a modest sport fishery. Since 1969, the resource has seriously deteriorated. Commercial landings amounted to only 6 million pounds in 1976, and included proportionally more immature perch than in the 1960's. Moreover, no strong year classes were produced between 1965 and 1975. An interagency technical committee was appointed in 1975 by the Lake Erie Committee of the Great Lakes Fishery Commission to develop an interim management strategy that would provide for greater protection of perch in western Lake Erie, where declines have been the most severe. The committee first determined the age structure, growth and mortality rates, maturation schedule, and length-fecundity relationship for the population, and then applied Ricker-type equilibrium yield models to determine the effects of various minimum length limits on yield, production, average stock weight, potential egg deposition, and the Abrosov spawning frequency indicator (average number of spawning opportunities per female). The committee recommended increasing the minimum length limit of 5.0 inches to at least 8.5 inches. Theoretically, this change would increase the average stock weight by 36% and potential egg deposition by 44%, without significantly decreasing yield. Abrosov's spawning frequency indicator would rise from the existing 0.6 to about 1.2.

Do necrophagous blowflies (Diptera: Calliphoridae) lay their eggs in wounds?: Experimental data and implications for forensic entomology.

PubMed

Charabidze, Damien; Depeme, Aurore; Devigne, Cedric; Hedouin, Valery

2015-08-01

This study was designed to examine the common belief that necrophagous blowflies lay their eggs in wounds. The egg-laying behaviour of Lucilia sericata was observed under controlled conditions on wet, artificially wounded or short-haired areas of rat cadavers. Flies laid significantly more eggs on the wet area and the area with short hair than on the dry area or area with long hair. No eggs were observed inside the wounds in any of the replicates. The effect of egg immersion (body fluids often exudes in wounds) on the survival rate of larvae was also investigated. In low water condition, an average of 72.7±7.9% of the larvae survived and they reached a mean length of 7.5±0.6mm. In contrast, submerging eggs under a high volume of water strongly affected their survival rate (25±3.7%) and development. Similar results were observed using unfrozen pig blood instead of water. These data question the information found in the literature regarding the preferential egg-laying behaviour of Calliphorids flies in wounds. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

9 CFR 592.510 - Basetime rate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Basetime rate. 592.510 Section 592.510 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.510 Basetime rate. (a) For each calendar year, FSIS will calculate the...

9 CFR 592.530 - Holiday rate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Holiday rate. 592.530 Section 592.530 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.530 Holiday rate. When an official plant requires inspection service on a...

9 CFR 592.530 - Holiday rate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Holiday rate. 592.530 Section 592.530 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.530 Holiday rate. When an official plant requires inspection service on a...

9 CFR 592.530 - Holiday rate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Holiday rate. 592.530 Section 592.530 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.530 Holiday rate. When an official plant requires inspection service on a...

9 CFR 592.530 - Holiday rate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Holiday rate. 592.530 Section 592.530 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.530 Holiday rate. When an official plant requires inspection service on a...

9 CFR 592.520 - Overtime rate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Overtime rate. 592.520 Section 592.520 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.520 Overtime rate. When operations in an official plant require the...

9 CFR 592.510 - Basetime rate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Basetime rate. 592.510 Section 592.510 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.510 Basetime rate. (a) For each calendar year, FSIS will calculate the...

9 CFR 592.520 - Overtime rate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Overtime rate. 592.520 Section 592.520 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.520 Overtime rate. When operations in an official plant require the...

9 CFR 592.520 - Overtime rate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Overtime rate. 592.520 Section 592.520 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.520 Overtime rate. When operations in an official plant require the...

9 CFR 592.520 - Overtime rate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Overtime rate. 592.520 Section 592.520 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION VOLUNTARY INSPECTION OF EGG PRODUCTS Fees and Charges § 592.520 Overtime rate. When operations in an official plant require the...

Precooling treatments induce resistance of Anastrepha ludens eggs to quarantine treatments of high-pressure processing combined with cold.

PubMed

Castañón-Rodríguez, J F; Velazquez, G; Montoya, P; Vázquez, M; Ramírez, J A

2014-04-01

High-pressure processing (HPP) combined with heat or cold has been proposed as an alternative quarantine process for Mexican fruit fly Anastrepha ludens Loew (Diptera: Tephritidae). HPP conditions at levels higher than 100 MPa applied to destroy eggs and larvae can also affect the postharvest physiology of the fruits. HPP at pressure levels in the range of 50-100 MPa is recommended. Eggs have been reported as being more resistant to HPP than larvae. Therefore, the objective of this study was to assess the effect of a precooling treatment on the biological viability of A. ludens eggs treated by HPP at 0 degrees C. The capability of nondestroyed eggs to develop and reproduce was also evaluated. One-, 2-, 3-, and 4-d-old eggs were precooled in ice water for 0 (control) 3, 6, 12, or 24 h and then pressurized at 50, 70, or 90 MPa for 0, 3, 6, or 9 min at 0 degrees C. The hatching capability of pressurized eggs was evaluated. The most lethal effect of HPP on nonprecooled eggs (0 h) was obtained at 90 MPa for 9 min, destroying all eggs except for the 3-d-old ones, which showed an 11.8% hatch rate. Precooling treatment improved the hatch rate of eggs ranging from 4 to 50% depending on precooling conditions. The main effect was observed after 6 h. These results suggest that precooling modified the biochemistry and physiology of eggs, improving their resistance to HPP treatments.

Etiology of Early Lifestage Diseases, Project 84-44, 1985 Final Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sauter, R.W.

1986-10-01

Each year hatcheries experience loss of eggs, fry and fingerlings due to a group of poorly defined diseases called White Spot and Coagulated Yolk. Samples of maternal blood and ovarian fluid (coelomic fluid), as well as unfertilized eggs, were collected at spawning and subsequently tested for the presence of bacteria. Our tests reveal that there is a wide range in mortality rates experienced by the progeny of different brood salmon. Microbiologic tests revealed that these eggs contained a variety of both Gram positive and Gram negative bacteria within their yolk and that the fluids from the females who produced thesemore » lots were contaminated with a variety of bacteria. In contrast the eggs and maternal fluids from the six egg lots which experienced the lowest mortalities did not contain high numbers of Gram positive bacteria and contributed only 5% of the total mortalities observed within the 30 egg lots tested. From the 60 egg lots tested over two brood years we have isolated 18 different bacterial genera containing 32 different species from within the yolk surface sterilized, unfertilized eggs. Our tests suggest that Aeromonas hydrophila, Pseudomonas (3 species) Staphylococcus aureus, Vibrio sp., Corynebacterium hoffmanii, Listeria sp. and Bacillus sp. when detected within the yolk of eggs sampled from egg lots prior to fertilization will be associated with higher than normal mortality rates when the remainder of the egg lots containing these bacteria are incubated and reared. 36 refs., 16 figs.« less

Sulfated alpha-L-galactans from the sea urchin ovary: selective 6-desulfation as eggs are spawned.

PubMed

Cinelli, Leonardo P; Andrade, Leonardo; Valente, Ana Paula; Mourão, Paulo A S

2010-06-01

The sea urchin eggs are surrounded by a jelly coat, which contains sulfated polysaccharides with unique structures. These molecules are responsible for inducing the species-specific acrosome reaction, an obligatory event for the binding of sperm and fusion with the egg. The mechanism of biosynthesis of these sulfated polysaccharides is virtually unknown. The egg jelly of the sea urchin Echinometra lucunter contains a simple 2-sulfated, 3-linked alpha-L-galactan. Here, we pulse labeled the sea urchin ovary in vitro with (35)S-sulfate to follow the biosynthesis of the sulfated alpha-L-galactan. We found that the ovary contains a 2,6-disulfated, 3-linked alpha-L-galactan, which incorporates (35)S-sulfate more avidly than the 2-sulfated isoform. The 2,6-disulfated alpha-L-galactan was purified by anion exchange chromatography, analyzed by electrophoresis and characterized by 1D and 2D nuclear magnetic resonance spectra. We also investigated the location of the sulfated polysaccharides on the oocytes using histochemical procedures. The stain revealed high amounts of sulfated polysaccharide in mature oocytes and accessory cells. The amount of intracellular sulfated polysaccharides decreased as oocytes are spawned. We speculate that 2,6-disulfated galactan is initially synthesized in the ovary and that 6-sulfate ester is removed when the polysaccharide is secreted into the egg jelly. Similar events related to remodeling of sulfated polysaccharides have been reported in other biological systems.

Evaluation of potential mechanisms of atrazine-induced reproductive impairment in fathead minnow (Pimephales promelas) and Japanese medaka (Oryzias latipes)

USGS Publications Warehouse

Richter, Cathy; Papoulias, Diana M.; Whyte, Jeffrey J.; Tillitt, Donald E.

2016-01-01

Atrazine has been implicated in reproductive dysfunction of exposed organisms, and previous studies documented decreased egg production in Japanese medaka (Oryzias latipes) and fathead minnows (Pimephales promelas) during 30-d to 38-d exposures to 0.5 µg/L, 5 µg/L, and 50 µg/L atrazine. The authors evaluated possible mechanisms underlying the reduction in egg production. Gene expression in steroidogenesis pathways and the hypothalamus–pituitary–gonad axis of male and female fish was measured. Atrazine did not significantly induce gonad aromatase (cyp19a1a) expression. An atrazine-induced shift in the number of females in an active reproductive state was observed. Expression of the egg maturation genes vitellogenin 1 (vtg1) and zona pellucida glycoprotein 3.1 (zp3.1) in medaka females was correlated and had a bimodal distribution. In both species, females with low vtg1 or zp3.1 expression also had low expression of steroidogenesis genes in the gonad, estrogen receptor in the liver, and gonadotropins in the brain. In the medaka, the number of females per tank that had high expression of zp3.1 was significantly correlated with egg production per tank. The number of medaka females with low expression of zp3.1 increased significantly with atrazine exposure. Thus, the decline in egg production observed in response to atrazine exposure may be the result of a coordinated downregulation of genes required for reproduction in a subset of females.

Spacelab

NASA Image and Video Library

1994-07-01

Astronaut Donald Thomas conducts the Fertilization and Embryonic Development of Japanese Newt in Space (AstroNewt) experiment at the Aquatic Animal Experiment Unit (AAEU) inside the International Microgravity Laboratory-2 (IML-2) science module. The AstroNewt experiment aims to know the effects of gravity on the early developmental process of fertilized eggs using a unique aquatic animal, the Japanese red-bellied newt. The newt egg is a large single cell at the begirning of development. The Japanese newt mates in spring and autumn. In late autumn, female newts enter hibernation with sperm in their body cavity and in spring lay eggs and fertilize them with the stored sperm. The experiment takes advantage of this feature of the newt. Groups of newts were sent to the Kennedy Space Center and kept in hibernation until the mission. The AAEU cassettes carried four newts aboard the Space Shuttle. Two newts in one cassette are treated by hormone injection on the ground to simulate egg laying. The other two newts are treated on orbit by the crew. The former group started maturization of eggs before launch. The effects of gravity on that early process were differentiated by comparison of the two groups. The IML-2 was the second in a series of Spacelab flights designed to conduct research by the international science community in a microgravity environment. Managed by the Marshall Space Flight Center, the IML-2 was launched on July 8, 1994 aboard the STS-65 Space Shuttle mission, Orbiter Columbia.

Spacelab

NASA Image and Video Library

1994-07-01

Astronaut Donald Thomas conducts the Fertilization and Embryonic Development of Japanese Newt in Space (AstroNewt) experiment at the Aquatic Animal Experiment Unit (AAEU) inside the International Microgravity Laboratory-2 (IML-2) science module. The AstroNewt experiment aims to know the effects of gravity on the early developmental process of fertilized eggs using a unique aquatic animal, the Japanese red-bellied newt. The newt egg is a large single cell at the begirning of development. The Japanese newt mates in spring and autumn. In late autumn, female newts enter hibernation with sperm in their body cavity and in spring lay eggs and fertilized them with the stored sperm. The experiment takes advantage of this feature of the newt. Groups of newts were sent to the Kennedy Space Center and kept in hibernation until the mission. The AAEU cassettes carried four newts aboard the Space Shuttle. Two newts in one cassette are treated by hormone injection on the ground to simulate egg laying. The other two newts are treated on orbit by the crew. The former group started maturization of eggs before launch. The effects of gravity on that early process were differentiated by comparison of the two groups. The IML-2 was the second in a series of Spacelab flights designed to conduct research by the international science community in a microgravity environment. Managed by the Marshall Space Flight Center, the IML-2 was launch on July 8, 1994 aboard the STS-65 Space Shuttle Orbiter Columbia mission.

Comparison of the egg flotation and egg candling techniques for estimating incubation day of Canada Goose nests

USGS Publications Warehouse

Reiter, M.E.; Andersen, D.E.

2008-01-01

Both egg flotation and egg candling have been used to estimate incubation day (often termed nest age) in nesting birds, but little is known about the relative accuracy of these two techniques. We used both egg flotation and egg candling to estimate incubation day for Canada Geese (Branta canadensis interior) nesting near Cape Churchill, Manitoba, from 2000 to 2007. We modeled variation in the difference between estimates of incubation day using each technique as a function of true incubation day, as well as, variation in error rates with each technique as a function of the true incubation day. We also evaluated the effect of error in the estimated incubation day on estimates of daily survival rate (DSR) and nest success using simulations. The mean difference between concurrent estimates of incubation day based on egg flotation minus egg candling at the same nest was 0.85 ?? 0.06 (SE) days. The positive difference in favor of egg flotation and the magnitude of the difference in estimates of incubation day did not vary as a function of true incubation day. Overall, both egg flotation and egg candling overestimated incubation day early in incubation and underestimated incubation day later in incubation. The average difference between true hatch date and estimated hatch date did not differ from zero (days) for egg flotation, but egg candling overestimated true hatch date by about 1 d (true - estimated; days). Our simulations suggested that error associated with estimating the incubation day of nests and subsequently exposure days using either egg candling or egg flotation would have minimal effects on estimates of DSR and nest success. Although egg flotation was slightly less biased, both methods provided comparable and accurate estimates of incubation day and subsequent estimates of hatch date and nest success throughout the entire incubation period. ?? 2008 Association of Field Ornithologists.

Arabidopsis female gametophyte gene expression map reveals similarities between plant and animal gametes.

PubMed

Wuest, Samuel E; Vijverberg, Kitty; Schmidt, Anja; Weiss, Manuel; Gheyselinck, Jacqueline; Lohr, Miriam; Wellmer, Frank; Rahnenführer, Jörg; von Mering, Christian; Grossniklaus, Ueli

2010-03-23

The development of multicellular organisms is controlled by differential gene expression whereby cells adopt distinct fates. A spatially resolved view of gene expression allows the elucidation of transcriptional networks that are linked to cellular identity and function. The haploid female gametophyte of flowering plants is a highly reduced organism: at maturity, it often consists of as few as three cell types derived from a common precursor [1, 2]. However, because of its inaccessibility and small size, we know little about the molecular basis of cell specification and differentiation in the female gametophyte. Here we report expression profiles of all cell types in the mature Arabidopsis female gametophyte. Differentially expressed posttranscriptional regulatory modules and metabolic pathways characterize the distinct cell types. Several transcription factor families are overrepresented in the female gametophyte in comparison to other plant tissues, e.g., type I MADS domain, RWP-RK, and reproductive meristem transcription factors. PAZ/Piwi-domain encoding genes are upregulated in the egg, indicating a role of epigenetic regulation through small RNA pathways-a feature paralleled in the germline of animals [3]. A comparison of human and Arabidopsis egg cells for enrichment of functional groups identified several similarities that may represent a consequence of coevolution or ancestral gametic features. 2010 Elsevier Ltd. All rights reserved.

Dietary vitamin A, ascorbic acid and α-tocopherol affect the gonad development and reproductive performance of starry flounder Platichthys stellatus broodstock

NASA Astrophysics Data System (ADS)

Wang, Jiying; Li, Baoshan; Liu, Xudong; Ma, Jingjing; Wang, Shixin; Zhang, Limin

2014-03-01

The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and α-tocopherol on the gonadal development and reproductive performance. 8 000 IU/kg diet vitamin A (VA group), 500 mg/kg diet ascorbic acid (Vcpp group), or 250 mg/kg diet α-tocopherol (α-TA group) was added into basal diet to create 3 vitamin experimental diets, respectively. Each diet was fed to 450 starry flounder broodstock for 104 days. Samples were collected weekly. The gonadosomatic index (GSI) of 3 vitamin experimental groups first decreased and then increased. Maximum GSI of Vcpp group was higher than that of α-TA group but lower than that of VA group. The spawning periods of 3 vitamin experimental groups lasted 49, 56, and 45 days, respectively. No mature eggs were observed in the control group during the trial. The absolute fecundity (AF) and relative fecundity (RF) of α-TA group was higher than that of Vcpp group but lower than that of VA group. The results suggest that different vitamins play different roles in the fish reproductive process. Vitamin A stimulated the maturation of the ovary, ascorbic acid prolonged the spawning period, and α-tocopherol affected the development of the eggs.

Nonlinear and correlational sexual selection on 'honest' female ornamentation.

PubMed Central

LeBas, Natasha R; Hockham, Leon R; Ritchie, Michael G

2003-01-01

Female ornamentation has long been overlooked because of the greater prevalence of elaborate displays in males. However, the circumstances under which females would benefit from honestly signalling their quality are limited. Females are not expected to invest in ornamentation unless the fitness benefits of the ornament exceed those derived from investing the resources directly into offspring. It has been proposed that when females gain direct benefits from mating, females may instead be selected for ornamentation that deceives males about their reproductive state. In the empidid dance flies, males frequently provide nuptial gifts and it is usually only the female that is ornamented. Female traits in empidids, such as abdominal sacs and enlarged pinnate leg scales, have been proposed to 'deceive' males into matings by disguising egg maturity. We quantified sexual selection in the dance fly Rhamphomyia tarsata and found escalating, quadratic selection on pinnate scales and that pinnate scales honestly reflect female fecundity. Mated females had a larger total number and more mature eggs than unmated females, highlighting a potential benefit rather than a cost of male mate choice. We also show correlational selection on female pinnate scales and fecundity. Correlational selection, equivalent investment patterns or increased nutrition from nuptial gifts may all maintain honesty in female ornamentation. PMID:14561280

Life history of the vulnerable endemic crayfish Cambarus (Erebicambarus) maculatus Hobbs and Pflieger, 1988 (Decapoda: Astacoidea: Cambaridae) in Missouri, USA

USGS Publications Warehouse

DiStefano, Robert J.; Westhoff, Jacob T.; Ames, Catlin W.; Rosenberger, Amanda E.

2016-01-01

The vulnerable freckled crayfish, Cambarus maculatus Hobbs and Pflieger, 1988, is endemic to only one drainage in eastern Missouri, USA, which is impacted by heavy metals mining and adjacent to a rapidly-expanding urban area. We studied populations of C. maculatus in two small streams for 25 months to describe annual reproductive cycles, and gather information about fecundity, sex ratio, size at maturity, size-class structure, and growth, capturing a monthly average of more than 50 individuals from each of the two study populations. Information about the density of the species at supplemental sampling streams was also obtained. The species exhibited traits consistent with a K-strategist life history; long-lived, slow-growing, with fewer but larger eggs than sympatric crayfish species. Breeding season occurred in mid- to late autumn, potentially extending into early winter. Egg brooding occurred primarily in May. Young of year were first observed in June. We estimated that these populations contained four to six size-classes, observed smaller individuals grew faster than larger individuals, and most became sexually mature in their second year of life. Densities of C. maculatus were low relative to several sympatric species of Orconectes Cope, 1872. Life history information presented herein will be important for anticipated future conservation efforts.

The Origin and Fate of Annulate Lamellae in Maturing Sand Dollar Eggs

PubMed Central

Merriam, R. W.

1959-01-01

Electron micrograph evidence is presented that the nuclear envelope of the mature ovum of Dendraster excentricus is implicated in a proliferation of what appear as nuclear envelope replicas in the cytoplasm. The proliferation is associated with intranuclear vesicles which apparently coalesce to form comparatively simple replicas of the nuclear envelope closely applied to the inside of the nuclear envelope. The envelope itself may become disorganized at the time when fully formed annulate lamellae appear on the cytoplasmic side and parallel with it. The concept of interconvertibility of general cytoplasmic vesicles with most of the membrane systems of the cytoplasm is presented. The structure of the annuli in the annulate lamellae is shown to include small spheres or vesicles of variable size embedded in a dense matrix. Dense particles which are about 150 A in diameter are often found closely associated with annulate lamellae in the cytoplasm. Similar structures in other echinoderm eggs are basophilic. In this species, unlike other published examples, the association apparently takes place in the cytoplasm only after the lamellae have separated from the nucleus. If 150 A particles are synthesized by annulate lamellae, as their close physical relationship suggests, then in this species at least the necessary synthetic mechanisms and specificity must reside in the structure of annulate lamellae. PMID:13630942

Reproduction, growth and vertical distribution of the meso- and bathypelagic fish Cyclothone atraria (Pisces: Gonostomatidae) in Sagami Bay, Central Japan

NASA Astrophysics Data System (ADS)

Miya, Masaki; Nemoto, Takahisa

1987-09-01

The life history and vertical distribution of the meso- and bathypelagic fish Cyclothone atraria (family Gonostomatidae) are described on the basis of about 9800 specimens taken during a series of 20 cruises from December 1982 to November 1985 at a station near the center of Sagami Bay, Central Japan. C. atraria does not undertake overall diel vertical migrations, being concentrated in the lower mesopelagic and bathypelagic zones below 400 m, with peak abundance at about 600 m both day and night. Spawning occurs mainly during the summer and early autumn. C. atraria releases about 500-3000 eggs at once and may spawn several times during its life span. Duration of the egg and larval stages is estimated to be about 6-7 months. C. atraria is protandrous, attaining male maturation in 3 years at about 25 mm standard length (SL) and attaining female maturation in 5-6 years at about 40 mm SL. Length-frequency analysis demonstrated that modal progressions could be followed until about 55 mm SL; however, no length mode that increases with time was observed at 30-35 mm SL, which corresponds to the size of sex reversal. Such modal indistinctness results from rapid growth of individual fishes set free from male breeding activity during protracted spawning season.

Changes in sex steroid hormone levels reflect the reproductive status of captive female zebra sharks (Stegostoma fasciatum).

PubMed

Nozu, Ryo; Murakumo, Kiyomi; Yano, Nagisa; Furuyama, Rina; Matsumoto, Rui; Yanagisawa, Makio; Sato, Keiichi

2018-03-03

Captive breeding in aquaria is a useful means for ex situ preservation of threatened elasmobranch species. To promote captive breeding, it is important to determine the female reproductive status. However, information regarding reproductive status in female elasmobranchs is limited. Here, we used zebra sharks, Stegostoma fasciatum, as a model for elasmobranch reproduction in captivity. We investigated the relationships among changes in the sex steroid hormone levels, follicle size, and egg-laying period to develop indicators for the female reproductive status. We confirmed that mature female zebra sharks undergo an annual reproductive cycle. Additionally, we showed that the variations in sex steroid hormone levels correlated with reproductive status in mature female zebra sharks. Plasma estradiol-17ß (E2) concentrations increased two months before ovarian follicle development and decreased along with follicle regression. Interestingly, E2 levels were inversely correlated with water temperature (R = -0.901). Moreover, high levels of testosterone (T) correlated well with the laying period. These results strongly suggest that E2 is an indicator for ovarian follicle development, and that T is a useful indicator for both the onset and end of the egg-laying period in captive zebra sharks. Copyright © 2018 Elsevier Inc. All rights reserved.

Cold storage effects on egg hatch in laboratory-reared Culicoides variipennis sonorensis (Diptera: Ceratopogonidae).

PubMed

Hunt, G J; Tabachnick, W J

1995-09-01

The effects of cold storage (5 degrees C) on the hatching rates of laboratory-reared Culicoides variipennis sonorensis eggs were examined. Mortality increased with storage time. Average maximum embryo survivorship for 4 trials was 55.0 +/- 4.2 (+/- SEM) days. Alternating daily cycles of high and then low mean hatching rates occurred and possibly were due to location differences in temperature within the temperature-controlled rearing system. During cold storage at 5 degrees C, C. v. sonorensis eggs may be kept for ca. 28 days with an anticipated hatching rate of about 50%.

Temperature effects on egg development and larval condition in the lesser sandeel, Ammodytes marinus

NASA Astrophysics Data System (ADS)

Régnier, Thomas; Gibb, Fiona M.; Wright, Peter J.

2018-04-01

Understanding the influence of temperature on egg development and larval condition in planktonic fish is a prerequisite to understanding the phenological impacts of climate change on marine food-webs. The lesser sandeel, Ammodytes marinus (Raitt 1934), is a key trophic link between zooplankton and many piscivorous fish, sea birds and mammals in the northeast Atlantic. Temperature-egg development relationships were determined for batches of lesser sandeel eggs. Hatching began as early as 19 days post fertilisation at 11 °C and as late as 36 days post fertilisation at 6 °C, which is faster than egg development rates reported for closely related species at the lower end of the tested temperature range. The average size of newly hatched larvae decreased with increasing incubation temperatures in early hatching larvae, but this effect was lost by the middle of the hatching period. While the study revealed important temperature effects on egg development rate, predicted variability based on the range of temperatures eggs experience in the field, suggests it is only a minor contributor to the observed inter-annual variation in hatch date.

Development and survival of Anopheles gambiae eggs in drying soil: influence of the rate of drying, egg age, and soil type.

PubMed

Shililu, J I; Grueber, W B; Mbogo, C M; Githure, J I; Riddiford, L M; Beier, J C

2004-09-01

Little is known about the contribution made by the egg stage of African malaria vectors to the rapid rise in adult populations following the onset of seasonal rains. To examine this issue, we evaluated the viability of Anopheles gambiae eggs in drying soil in the laboratory. Survival data were collected from field-caught mosquitoes kept in sandy loam soil and laboratory-reared colonies kept in sandy loam soil and black cotton soil. Under high, medium, and low soil-moisture regimes, egg viability declined sharply with increased duration of drying. Eggs remained viable in drying sandy loam soil for 1, 5, and 10 days, but not after 15 or 20 days. The most dramatic decline in hatching success occurred between drying days 1 (78-83% hatch) and 5 (20-23% hatch). In contrast, eggs reared in high-moisture black cotton soil remained viable for up to 15 days. Furthermore, after 5 drying days, high-, medium-, and low-moisture soils averaged 59, 47, and 31% hatching success, respectively. We recovered unhatched eggs from sandy loam soils to examine the developmental status of the embryos. A majority of the unhatched eggs that were recovered from days 15 and 20 in sandy loam soils contained fully developed late-stage embryos. Thus, unhatched eggs completed embryonic development but probably died before receiving an appropriate hatching stimulus. Our results suggest that the absolute moisture content of the soil does not alone determine hatching success of anopheline eggs. Rather, soil moisture, together with the rate of drying, physiological factors associated with the age of the egg, and the type of soil in which the egg rests likely influence survival.

Dogs cloned from adult somatic cells.

PubMed

Lee, Byeong Chun; Kim, Min Kyu; Jang, Goo; Oh, Hyun Ju; Yuda, Fibrianto; Kim, Hye Jin; Hossein, M Shamim; Shamim, M Hossein; Kim, Jung Ju; Kang, Sung Keun; Schatten, Gerald; Hwang, Woo Suk

2005-08-04

Several mammals--including sheep, mice, cows, goats, pigs, rabbits, cats, a mule, a horse and a litter of three rats--have been cloned by transfer of a nucleus from a somatic cell into an egg cell (oocyte) that has had its nucleus removed. This technology has not so far been successful in dogs because of the difficulty of maturing canine oocytes in vitro. Here we describe the cloning of two Afghan hounds by nuclear transfer from adult skin cells into oocytes that had matured in vivo. Together with detailed sequence information generated by the canine-genome project, the ability to clone dogs by somatic-cell nuclear transfer should help to determine genetic and environmental contributions to the diverse biological and behavioural traits associated with the many different canine breeds.

Reproductive bionomics and life history traits of three gammaridean amphipods, Cymadusa filosa Savigny, Ampithoe laxipodus Appadoo and Myers and Mallacoota schellenbergi Ledoyer from the tropical Indian Ocean (Mauritius)

NASA Astrophysics Data System (ADS)

Appadoo, Chandani; Myers, Alan A.

2004-12-01

The reproductive bionomics and life history traits of two corophiid amphipods ( Ampithoe laxipodus, Cymadusa filosa) and one melitid ( Mallacoota schellenbergi) were studied in Mauritius (Indian Ocean) for the period March 1999 to February 2000. Results on the population structure, monthly size class variations, sex ratio, female reproductive states and fecundity are presented. The study demonstrates multivoltinism and continuous reproduction in the three species. Increase in number of juveniles was observed in warmer months for C. filosa and A. laxipodus. Sexual maturity was attained at smaller sizes in warmer months in the three species. Linear relationship on body length and number of eggs in brood pouch are presented. Size-independent analysis of egg number revealed a decrease in number of eggs in cooler months. Sex ratio is male skewed in M. schellenbergi and female skewed in C. filosa and A. laxipodus. Some of the plausible explanations for the reproductive strategies adopted by these three species in a tropical system are discussed.

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

DOE PAGES

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.; ...

2014-12-15

Fertilization of a mammalian egg induces a series of ‘zinc sparks’ that are necessary for inducing the egg-to-embryo transition. Despite the importance of these zinc efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches to resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy dispersive spectroscopy, X-ray fluorescence microscopy, and 3D elemental tomography for high resolution elemental mapping. Here we show that the zinc spark arises from a system of thousands ofmore » zinc-loaded vesicles, each of which contains, on average, 106 zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. We conclude that the discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes.« less

Marchantia MpRKD Regulates the Gametophyte-Sporophyte Transition by Keeping Egg Cells Quiescent in the Absence of Fertilization.

PubMed

Rövekamp, Moritz; Bowman, John L; Grossniklaus, Ueli

2016-07-11

Unlike in animals, the life cycle of land plants alternates between two multicellular generations, the haploid gametophyte and the diploid sporophyte [1]. Gamete differentiation initiates the transition from the gametophyte to the sporophyte generation and, upon maturation, the egg cell establishes a quiescent state that is maintained until fertilization. This quiescence represents a hallmark of the gametophyte-sporophyte transition. The underlying molecular mechanisms are complex and best characterized in the flowering plant Arabidopsis thaliana [2-4]. However, only few genes with egg cell-specific expression or defects have been identified [5-10]. Intriguingly, ectopic expression of members of a clade of RWP-RK domain (RKD)-containing transcription factors, which are absent from animal genomes [11-13], can induce an egg cell-like transcriptome in sporophytic cells of A. thaliana. Yet, to date, loss-of-function experiments have not produced phenotypes affecting the egg cell, likely due to genetic redundancy and/or cross-regulation among the five RKD genes of A. thaliana [10]. To reduce genetic complexity, we explored the genome of Marchantia polymorpha, a liverwort belonging to the basal lineage of extant land plants [14-17]. Based on sequence homology, we identified a single M. polymorpha RKD gene, MpRKD, which is orthologous to all five A. thaliana RKD genes. Analysis of the MpRKD expression pattern and characterization of lines with reduced MpRKD activity indicate that it functions as a regulator of gametophyte development and the gametophyte-sporophyte transition. In particular, MpRKD is required to establish and/or maintain the quiescent state of the egg cell in the absence of fertilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Breeding value prediction for production traits in layer chickens using pedigree or genomic relationships in a reduced animal model.

PubMed

Wolc, Anna; Stricker, Chris; Arango, Jesus; Settar, Petek; Fulton, Janet E; O'Sullivan, Neil P; Preisinger, Rudolf; Habier, David; Fernando, Rohan; Garrick, Dorian J; Lamont, Susan J; Dekkers, Jack C M

2011-01-21

Genomic selection involves breeding value estimation of selection candidates based on high-density SNP genotypes. To quantify the potential benefit of genomic selection, accuracies of estimated breeding values (EBV) obtained with different methods using pedigree or high-density SNP genotypes were evaluated and compared in a commercial layer chicken breeding line. The following traits were analyzed: egg production, egg weight, egg color, shell strength, age at sexual maturity, body weight, albumen height, and yolk weight. Predictions appropriate for early or late selection were compared. A total of 2,708 birds were genotyped for 23,356 segregating SNP, including 1,563 females with records. Phenotypes on relatives without genotypes were incorporated in the analysis (in total 13,049 production records).The data were analyzed with a Reduced Animal Model using a relationship matrix based on pedigree data or on marker genotypes and with a Bayesian method using model averaging. Using a validation set that consisted of individuals from the generation following training, these methods were compared by correlating EBV with phenotypes corrected for fixed effects, selecting the top 30 individuals based on EBV and evaluating their mean phenotype, and by regressing phenotypes on EBV. Using high-density SNP genotypes increased accuracies of EBV up to two-fold for selection at an early age and by up to 88% for selection at a later age. Accuracy increases at an early age can be mostly attributed to improved estimates of parental EBV for shell quality and egg production, while for other egg quality traits it is mostly due to improved estimates of Mendelian sampling effects. A relatively small number of markers was sufficient to explain most of the genetic variation for egg weight and body weight.

Is the idea of a fast block to polyspermy based on artifact?

PubMed

Dale, Brian

2014-08-01

This purpose of this review is to look at the experimental evidence, both kinetic and electrophysiological, that led to the hypothesis of a fast electrical block to polyspermy in sea urchin eggs. The idea of a fast partial block, forwarded in the 1950's, that would reduce the receptivity of the egg surface by 1/20th following its interaction with the fertilizing spermatozoon, was based on experiments that treated fertilization as a first order chemical reaction. Here, I outline the criticisms of the Rothschild theory and demonstrate that the hypothesis of a fast partial block to polyspermy is unfounded. Notwithstanding, it was suggested in the 1970's that the membrane depolarization, induced by the fertilizing spermatozoon, prevented the interaction of supernumerary spermatozoa, the fast electrical block to polyspermy. While trans-membrane voltage recording has permitted a better understanding of the sequence of events occurring at fertilization, there is no evidence that depolarization prevents the interaction of supernumerary spermatozoa. Sperm entry is prevented at positive and negative potentials, in the voltage clamp configuration, however this is an artifact caused by the currents injected into the egg employed to hold the voltage constant in a non-physiological range. At permissive voltages, around -20 mV, where the current required to hold the voltage is minimal, only one spermatozoon normally enters the egg. Thus, irrespective of the egg voltage, the fertilizing spermatozoon is, in any case, attached to a privileged interaction site that permits entry and distinguishes it from supernumerary spermatozoa. Competence for monospermy is acquired during oocyte maturation and data on cortical organization in echinoderm eggs points to the actin filament system for regulating sperm entry. Copyright © 2014 Elsevier Inc. All rights reserved.

Brain arginine vasotocin and isotocin in breeding female three-spined sticklebacks (Gasterosteus aculeatus): the presence of male and egg deposition.

PubMed

Kulczykowska, Ewa; Kleszczyńska, Agnieszka

2014-08-01

Arginine vasotocin (AVT) and isotocin (IT) are fish hypothalamic nonapeptides involved in numerous social and reproductive behaviors. Vasotocinergic and isotocinergic fibers project to different brain areas where peptides act as neurotransmitters and/or neuromodulators. In this study, we measured whole brain levels of bioactive AVT and IT in breeding females of three-spined stickleback (Gasterosteus aculeatus) when they were kept with: (i) courting nest-owners, (ii) courting males that did not build the nest, (iii) non-courting males, and (iv) alone. Only some of the females kept with courting nest-owners deposited eggs. The highest and similar brain AVT levels were in those of females that did not deposit eggs, regardless of whether they were kept with non-courting or courting male, having the nest or not. The highest IT levels were in females that did not deposit eggs but only in those kept with courting male. We suggest that production of AVT in females' brain is stimulated by the presence of male in close proximity, irrespective of whether or not it displays courting behavior, but that of IT is stimulated by male courtship proxies. Moreover, presence of courting or non-courting male that stimulate IT or/and AVT producing neurones may be decisive for final oocyte maturation or egg deposition, because brain levels of both nonapeptides decrease after egg deposition. Similar AVT levels in brains of aggressive and non-aggressive individuals and lack of correlation between brain IT levels and aggressive behavior of females suggest that the nonapeptides are not related to females aggressiveness in three-spined sticklebacks. Copyright © 2014. Published by Elsevier Inc.

Life history and demography of the common mud turtle Kinosternon subrubrum in South Carolina, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frazier, N.B.; Gibbons, J.W.; Greene, J.L.

1992-01-01

This paper presents a life table for the common mud turtle, Kinosternon subrubrum, in a fluctuating aquatic habitat on the Upper Coastal Plain of South Carolina, USA, using data gathered in a 20-yr mark-recapture study. Data on survivorship and fecundity were assessed and compared to previously published life table statistics for the slider turtle, Trachemys scripta, in the same body of water and for the yellow mud turtle, K. flavscens, in Nebraska. The annual survival rate for adult female Kinosternon is significantly higher than that of adult female Trachemys. Similarly, male Kinosternon exhibit an annual survival rate significantly higher thanmore » that of male Trachemys. The mean annual proportion of female Kinosternon that are reproductively active also is significantly higher than that of Trachemys. In addition, survival rate from the time eggs are laid by Kinosternon until the hatchlings enter the aquatic environment is significantly higher than that for Trachemys. Comparisons of findings with those for K. flavesens indicate that these geographically separate populations of congeneric species also differ substantially in age at maturity, mean generation time, and the mean proportion of females that are reproductively active in any given year. Differences were also apparent in mean clutch frequencies and adult survival rates.« less

[Seasonal variations in Aedes Aegypti populations in Monterrey, Mexico].

PubMed

Salas-Luévano, M A; Reyes-Villanueva, F

1994-01-01

Seasonal variation of the populations of the dengue vector mosquito Aedes aegypti, in the city of Monterrey, N.L., Mexico, showed a bimodal pattern. The first peak is lower and appeared at early June, while the second and higher one was observed in the second week of October. 1,419 female mosquitoes were caught in this study. Females with fresh red blood in the stomach were present in all the catches, gravid females (mature eggs in the ovaries) being more abundant than the non-gravid ones. The gravid females with red blood are the oldest of the vector population. Nevertheless, in October, 40 per cent of females had red blood and of these, 37 per cent were gravid. In relation to the biting rate, a 10 females/hour-man rate was recorded for the first peak and a 13.3 females/hour-man rate for the second one. There were 32 per cent of females involved in multiple feedings during the weekly catches. This incidence increases to 40 per cent in October. These rates were calculated on the basis of females with fresh blood in the stomach; from these the gravids and non-gravids have at least three and two multiple feedings, respectively. Finally the epidemiological importance of these multiple feedings on dengue transmission is discussed.

Recombinant luteinizing hormone priming in multiple follicular stimulation for in-vitro fertilization in downregulated patients.

PubMed

Lisi, F; Caserta, D; Montanino, M; Berlinghieri, V; Bielli, W; Carfagna, P; Carra, M C; Costantino, A; Lisi, R; Poverini, R; Ciardo, F; Rago, R; Marci, R; Moscarini, M

2012-09-01

Follicle development is controlled amongst other factors by pituitary gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) that act in synergy in completing follicle maturation. Exogenous gonadotropins, combined with gonadotropin-releasing hormone agonists, have been successfully used in patients with ovulatory disorders undergoing assisted reproduction. There is some evidence of a beneficial role of androgens or LH administration before FSH stimulation. This study was designed to verify whether the addition of LH in the early follicular phase, in downregulated patients undergoing follicular stimulation for assisted reproduction, would add benefits in terms of general outcomes and pregnancy rates. We compared two groups of patients one of which was treated with recombinant FSH (rFSH) alone and the other with rFSH plus recombinant LH (rLH), in the early follicular phase only. The number of eggs recovered was higher in the group treated with FSH only; however, the number of embryos available at transfer was similar in the two groups and, more importantly, the number of Grades I and II embryos was higher in the group pretreated with LH. Similarly, although biochemical pregnancy rate and clinical pregnancy rates were similar in both groups, a beneficial role of LH priming was demonstrated by the higher implantation rate achieved in these patients.

The effects of ingested petroleum on oviposition and some aspects of reproduction in experimental colonies of mallard ducks (Anas platyrhynchos)

USGS Publications Warehouse

Holmes, W.N.; Cavanaugh, K.P.; Cronshaw, J.

1978-01-01

Compared to unmated mallard ducks fed an uncontaminated diet, unmated birds given food contaminated with 3 ml South Louisiana crude oil per 100 g dry weight showed an 84% decline in the daily rate of oviposition, a 33% decrease in egg-shell thickness and at autopsy more than 82% of the ovarian mass consisted of atretic follicles. Similar studies on groups of mated females showed that although the addition of 1 ml South Louisiana crude oil/100 g dry food had no effect on the daily rate of oviposition, none of the eggs had been fertilized while a concentration of 3 ml South Louisiana crude oil/100 g dry food suppressed the daily rate of oviposition significantly. Less than 25% of these eggs had been fertilized and only 40% of the fertilized eggs yielded viable ducklings. In both of these groups of mated birds, normal patterns of oviposition, fertilization and hatchability were restored after removal of petroleum from the diet. The addition of 1 ml Kuwait crude oil/100 g dry food had no effect on the rate of oviposition, the incidence of fertility or the hatchability of the fertilized eggs. The addition of 3 ml oil/100 g dry food completely abolished oviposition, but a normal rate of oviposition was restored when the concentration of the crude oil was reduced from 3 to 1 ml/100 g dry food. However, the incidence of fertilization remained low and none of the fertilized eggs gave rise to viable ducklings. Kuwait crude oil had no effect on shell thickness.

Absorption of current use pesticides by snapping turtle (Chelydra serpentina) eggs in treated soil.

PubMed

Solla, Shane Raymond de; Martin, Pamela Anne

2011-10-01

Reptiles often breed within agricultural and urban environments that receive frequent pesticide use. Consequently, their eggs and thus developing embryos may be exposed to pesticides. Our objectives were to determine (i) if turtle eggs are capable of absorbing pesticides from treated soil, and (ii) if pesticide absorption rates can be predicted by their chemical and physical properties. Snapping turtle (Chelydra serpentina) eggs were incubated in soil that was treated with 10 pesticides (atrazine, simazine, metolachlor, azinphos-methyl, dimethoate, chlorpyrifos, carbaryl, endosulfan (I and II), captan, and chlorothalonil). There were two treatments, consisting of pesticides applied at application rate equivalents of 1.92 or 19.2 kg a.i/ha. Eggs were removed after one and eight days of exposure and analyzed for pesticides using gas chromatography coupled with a mass selective detector (GC-MSD) or high performance liquid chromatography (HPLC). Absorption of pesticides in eggs from soil increased with both magnitude and duration of exposure. Of the 10 pesticides, atrazine and metolachlor generally had the greatest absorption, while azinphos-methyl had the lowest. Chlorothalonil was below detection limits at both exposure rates. Our preliminary model suggests that pesticides having the highest absorption into eggs tended to have both low sorption to organic carbon or lipids, and high water solubility. For pesticides with high water solubility, high vapor pressure may also increase absorption. As our model is preliminary, confirmatory studies are needed to elucidate pesticide absorption in turtle eggs and the potential risk they may pose to embryonic development. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Reduced egg shell permeability affects embryonic development and hatchling traits in Lycodon rufozonatum and Pelodiscus sinensis.

PubMed

Tang, Wenqi; Zhao, Bo; Chen, Ye; DU, Weiguo

2018-01-01

The response of embryos to unpredictable hypoxia is critical for successful embryonic development, yet there remain significant gaps in our understanding of such responses in reptiles with different types of egg shell. We experimentally generated external regional hypoxia by sealing either the upper half or bottom half of the surface area of eggs in 2 species of reptiles (snake [Lycodon rufozonatum] with parchment egg shell and Chinese soft-shelled turtle [Pelodiscus sinensis] with rigid egg shell), then monitored the growth pattern of the opaque white patch in turtle eggs (a membrane that attaches the embryo to the egg shell and plays an important role in gas exchange), the embryonic heart rate, the developmental rate and the hatchling traits in turtle and snake eggs in response to external regional hypoxia. The snake embryos from the hypoxia treatments facultatively increased their heart rate during incubation, and turtle embryos from the upper-half hypoxia treatment enhanced their growth of the opaque white patch. Furthermore, the incubation period and hatching success of embryos were not affected by the hypoxia treatment in these 2 species. External regional hypoxia significantly affected embryonic yolk utilization and offspring size in the snake and turtle. Compared to sham controls, embryos from the upper-half hypoxia treatment used less energy from yolk and, therefore, developed into smaller hatchlings, but embryos from the bottom-half hypoxia treatment did not. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Village poultry production systems in the central highlands of Ethiopia.

PubMed

Dessie, T; Ogle, B

2001-12-01

Participatory rural appraisal (PRA), supported by checklists and intensive case studies on individual households, was carried out in three villages at three different altitudes in the central highlands of Ethiopia. The chicken production system in each village is described and the problems are discussed. More than 60% of the families kept chickens, and in most cases the women owned and managed the birds and controlled the cash from the sales. The production systems followed were mainly low-input and small-scale, with 7-10 mature birds per household, reared in the back yards with inadequate housing, feeding and health care. The average egg production per clutch was 15-20, with 3-4 clutches per year. The mean number of eggs set per bird was 12.9 +/- 2.2 (n = 160), depending on the size of the bird and season, and the hatching rate was 80.9% +/- 11.1%, range 44%-100% (n = 160). Poultry meat and eggs were generally accepted and appreciated in all three villages. In addition to the small amount of cash income they provide, scavenging chickens have nutritional, cultural and social functions. The flock composition, price of poultry and poultry products, disease outbreaks and hatching of chicks were strongly affected by season. Disease was cited as the most important problem by most of the members of the community, followed by predation, lack of feed, poor housing, insufficient water and parasites. Disease periodically decimated the flocks, and consequently, about 50% of the eggs produced were incubated in order to replace the birds that had died. The major source of loss in the system was the high mortality of chicks (61%) that occurred between hatching and the end of brooding at 8 weeks of age. The system was characterized by no or few inputs and a low output level. The major input was the cost of foundation stock, but after that virtually no cost was involved. The major source of feed for the birds was from the scavenging feed resource base, which comprised table leftovers, small grain supplements and anything edible from the immediate environment.

Laying sequence interacts with incubation temperature to influence rate of embryonic development and hatching synchrony in a precocial bird.

PubMed

Hepp, Gary R; Kennamer, Robert A

2018-01-01

Incubation starts during egg laying for many bird species and causes developmental asynchrony within clutches. Faster development of late-laid eggs can help reduce developmental differences and synchronize hatching, which is important for precocial species whose young must leave the nest soon after hatching. In this study, we examined the effect of egg laying sequence on length of the incubation period in Wood Ducks (Aix sponsa). Because incubation temperature strongly influences embryonic development rates, we tested the interactive effects of laying sequence and incubation temperature on the ability of late-laid eggs to accelerate development and synchronize hatching. We also examined the potential cost of faster development on duckling body condition. Fresh eggs were collected and incubated at three biologically relevant temperatures (Low: 34.9°C, Medium: 35.8°C, and High: 37.6°C), and egg laying sequences from 1 to 12 were used. Length of the incubation period declined linearly as laying sequence advanced, but the relationship was strongest at medium temperatures followed by low temperatures and high temperatures. There was little support for including fresh egg mass in models of incubation period. Estimated differences in length of the incubation period between eggs 1 and 12 were 2.7 d, 1.2 d, and 0.7 d at medium, low and high temperatures, respectively. Only at intermediate incubation temperatures did development rates of late-laid eggs increase sufficiently to completely compensate for natural levels of developmental asynchrony that have been reported in Wood Duck clutches at the start of full incubation. Body condition of ducklings was strongly affected by fresh egg mass and incubation temperature but declined only slightly as laying sequence progressed. Our findings show that laying sequence and incubation temperature play important roles in helping to shape embryo development and hatching synchrony in a precocial bird.

Laying sequence interacts with incubation temperature to influence rate of embryonic development and hatching synchrony in a precocial bird

PubMed Central

Kennamer, Robert A.

2018-01-01

Incubation starts during egg laying for many bird species and causes developmental asynchrony within clutches. Faster development of late-laid eggs can help reduce developmental differences and synchronize hatching, which is important for precocial species whose young must leave the nest soon after hatching. In this study, we examined the effect of egg laying sequence on length of the incubation period in Wood Ducks (Aix sponsa). Because incubation temperature strongly influences embryonic development rates, we tested the interactive effects of laying sequence and incubation temperature on the ability of late-laid eggs to accelerate development and synchronize hatching. We also examined the potential cost of faster development on duckling body condition. Fresh eggs were collected and incubated at three biologically relevant temperatures (Low: 34.9°C, Medium: 35.8°C, and High: 37.6°C), and egg laying sequences from 1 to 12 were used. Length of the incubation period declined linearly as laying sequence advanced, but the relationship was strongest at medium temperatures followed by low temperatures and high temperatures. There was little support for including fresh egg mass in models of incubation period. Estimated differences in length of the incubation period between eggs 1 and 12 were 2.7 d, 1.2 d, and 0.7 d at medium, low and high temperatures, respectively. Only at intermediate incubation temperatures did development rates of late-laid eggs increase sufficiently to completely compensate for natural levels of developmental asynchrony that have been reported in Wood Duck clutches at the start of full incubation. Body condition of ducklings was strongly affected by fresh egg mass and incubation temperature but declined only slightly as laying sequence progressed. Our findings show that laying sequence and incubation temperature play important roles in helping to shape embryo development and hatching synchrony in a precocial bird. PMID:29373593

Effects of injected methylmercury on the hatching of common loon (Gavia immer) eggs

USGS Publications Warehouse

Kenow, Kevin P.; Meyer, Michael W.; Rossmann, Ronald; Gendron-Fitzpatrick, Annette; Gray, Brian R.

2011-01-01

To determine the level of in ovo methylmercury (MeHg) exposure that results in detrimental effects on fitness and survival of loon embryos and hatched chicks, we conducted a field study in which we injected eggs with various doses of MeHg on day 4 of incubation. Eggs were collected following about 23 days of natural incubation and artificially incubated to observe hatching. Reduced embryo survival was evident in eggs injected at a rate of ≥1.3 μg Hg/g wet-mass. When maternally deposited Hg and injected Hg were considered together, the median lethal concentration of Hg (LC50) was estimated to be 1.78 μg Hg/g wet-mass. Organ mass patterns from eggs of chicks injected at a rate of 2.9 μg Hg/g differed from that of controls and chicks from the 0.5 μg Hg/g treatment, largely related to a negative relation between yolk sac mass and egg mercury concentration. Chicks from eggs in the 2.9 μg Hg/g treatment were also less responsive to a frightening stimulus than controls and chicks from the 0.5 μg Hg/g treatment. We also found that the length of incubation period increased with increasing egg mercury concentration. Tissue Hg concentrations were strongly associated (r2 ≥ 0.80) with egg Hg concentration.

Facultative cardiac responses to regional hypoxia in lizard embryos.

PubMed

Du, Wei-Guo; Thompson, Michael B; Shine, Richard

2010-08-01

In natural nests, the eggs of squamate reptiles (lizards and snakes) sometimes experience unpredictable shifts in oxygen availability as a function of nest flooding, or the details of egg location within a nest. We experimentally investigated whether embryos can facultatively adjust cardiac function to cope with such challenges by imposing regional hypoxia on developing eggs of the scincid lizard Bassiana duperreyi. To do so, we sealed half of the eggshell surface with tissue adhesive. The embryos rapidly responded by increasing heart rates, which they maintained for long periods. The elevated heart rates enabled the embryos not only to survive, but to maintain "normal" metabolic rates, and to hatch at the usual time with unmodified phenotypic traits (e.g., hatchling size, relative heart mass, locomotor speed, post-hatchling survival and growth rates). Turtles and birds with rigid (highly calcified) eggshells show more dramatic ill-effects from hypoxic incubation, suggesting that the thin (and thus, highly gas-permeable) parchment-shelled eggs of most squamates allow more effective embryonic adjustment of oxygen exchange rates in response to externally-imposed hypoxia. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Influence of natural inshore and offshore thermal regimes on egg development and time of hatch in American lobsters, Homarus americanus.

PubMed

Goldstein, Jason S; Watson, Winsor H

2015-02-01

Some egg-bearing (ovigerous) American lobsters (Homarus americanus) make seasonal inshore-to-offshore movements, subjecting their eggs to different thermal regimes than those of eggs carried by lobsters that do not make these movements. Our goal was to determine if differences in thermal regimes influence the rate of egg development and the subsequent time of hatch. We subjected ovigerous lobsters to typical inshore or offshore water temperatures from September to August in the laboratory (n=8 inshore and 8 offshore, each year) and in the field (n=8 each, inshore and offshore), over 2 successive years. Although the rate of egg development did not differ significantly between treatments in the fall (P∼0.570), eggs exposed to inshore thermal regimes developed faster in the spring (P<0.001). "Inshore" eggs hatched about 30 days earlier (mean=26 June) than "offshore" eggs (mean=27 July), and their time of development from the onset of eyespot to hatch was significantly shorter (inshore=287±11 days vs. offshore: 311.5±7.5 days, P=0.034). Associated growing degree-days (GDD) did not differ significantly between inshore and offshore thermal treatments (P=0.061). However, eggs retained by lobsters exposed to offshore thermal regimes accumulated more GDD in the winter than did eggs carried by inshore lobsters, while eggs exposed to inshore temperatures acquired them more rapidly in the spring. Results suggest that seasonal movements of ovigerous lobsters influence the time and location of hatching, and thus the transport and recruitment of larvae to coastal and offshore locations. © 2015 Marine Biological Laboratory.

Human spermatozoa possess a calcium-dependent chloride channel that may participate in the acrosomal reaction

PubMed Central

Orta, Gerardo; Ferreira, Gonzalo; José, Omar; Treviño, Claudia L; Beltrán, Carmen; Darszon, Alberto

2012-01-01

Motility, maturation and the acrosome reaction (AR) are fundamental functions of mammalian spermatozoa. While travelling through the female reproductive tract, spermatozoa must mature through a process named capacitation, so that they can reach the egg and undergo the AR, an exocytotic event necessary to fertilize the egg. Though Cl− is important for sperm capacitation and for the AR, not much is known about the molecular identity of the Cl− transporters involved in these processes. We implemented a modified perforated patch-clamp strategy to obtain whole cell recordings sealing on the head of mature human spermatozoa. Our whole cell recordings revealed the presence of a Ca2+-dependent Cl− current. The biophysical characteristics of this current and its sensitivity to niflumic acid (NFA) and 4,4′-diisothiocyano-2,2′-stilbene disulphonic acid (DIDIS) are consistent with those displayed by the Ca2+-dependent Cl− channel from the anoctamin family (TMEM16). Whole cell patch clamp recordings in the cytoplasmic droplet of human spermatozoa corroborated the presence of these currents, which were sensitive to NFA and to a small molecule TMEM16A inhibitor (TMEM16Ainh, an aminophenylthiazole). Importantly, the human sperm AR induced by a recombinant human glycoprotein from the zona pellucida, rhZP3, displayed a similar sensitivity to NFA, DIDS and TMEM16Ainh as the sperm Ca2+-dependent Cl− currents. Our findings indicate the presence of Ca2+-dependent Cl− currents in human spermatozoa, that TMEM16A may contribute to these currents and also that sperm Ca2+-dependent Cl− currents may participate in the rhZP3-induced AR. PMID:22473777

Ecdysteroid hormone titer and its relationship to vitellogenesis in the soft tick, Ornithodoros moubata (Acari: Argasidae).

PubMed

Ogihara, Kazumasa; Horigane, Mari; Nakajima, Yoshiro; Moribayashi, Atsuko; Taylor, DeMar

2007-02-01

A blood meal is required for reproduction in most argasid female ticks. The blood meal appears to stimulate an organ in the posterior end to produce a fat body stimulating factor (FSF), which is thought to be an ecdysteroid, to induce vitellogenin (Vg) synthesis. In this study, the relationship of vitellogenesis and ecdysteroids was investigated by measuring Vg and ecdysteroid titers while observing oocyte development and oviposition in mated and virgin females. Oviposition occurred from day 10 after engorgement in mated females and continued up to 40-50 days, whereas egg maturation and oviposition did not occur in virgin females. Vg titers in the hemolymph peaked on day 6 after engorgement and subsequently declined in mated females. Interestingly, Vg synthesis occurred and ovarian development progressed to the development of early vitellogenic oocytes in virgin females but oocyte maturation and oviposition did not occur. Topical application of ecdysteroids induced oviposition in fed virgin females indicating that ecdysteroids may induce oviposition. Concentrations of ecdysteroids for 20 days after engorgement revealed several peaks in mated female whole body extracts, but no peaks in virgin female extracts. In the hemolymph of only mated females, ecdysteroid titers showed two peaks that followed the early peak of ecdysteroids in the whole body on day 4 and 6 after engorgement. In addition, ecdysteroids in the reproductive tissues increased with the development of the ovary in mated females and this increase coincided with the latter peaks of the whole body. These observations indicate that physiological elevation of ecdysteroids accelerate Vg synthesis, and may induce egg maturation and stimulate oviposition in fed mated Ornithodoros moubata females.

Feeding habits, sexual dimorphism and size at maturity of the lizard Cnemidophorus ocellifer (Spix, 1825) (Teiidae) in a reforested restinga habitat in northeastern Brazil.

PubMed

Santana, G G; Vasconcellos, A; Gadelha, Y E A; Vieira, W L S; Almeida, W O; Nóbrega, R P; Alves, R R N

2010-05-01

The feeding habits, the sexual dimorphism in size and sexual maturity of the actively foraging lizard Cnemidophorusocellifer were analysed in an area of a reforested Restinga habitat located in the municipality of Mataraca, along the northern-most coast of Paraíba State, Brazil. Seventy-five specimens of C. ocellifer were examined (46 males and 29A females). Of this total, only 23 specimens had prey in their stomachs. The most frequent prey consumed items were orthopterans (50%), coleopterans (23.9%) and arachnids (10.9%); termites and insect larvae were less consumed (both with 2.2%). There were no significant differences observed between the numbers of prey consumed by either males or females. There were significant differences in SVL (snout-vent length) between the sexes, with males attaining larger SVL values. When the influence of SVL was removed from the analyses, sexual dimorphism in the form was still reflected in the head size of these lizards. Sexual maturity in females and males was attained with SVL of 42.2 and 49.0 mm respectively. Although no significant difference was observed between the SVL of the females and the number of eggs produced, there was a clear tendency for larger females to produce more eggs. The low structural complexity of the vegetation and the poor soil quality in the reforested restinga area examined does not furnish favourable habitat for insect and termite larvae, contributing to the marked differences in the diet of the population of C. ocellifer observed in the present study in relation to the diet of their conspecifics in undisturbed areas of restinga, cerrado and caatinga.

Differences in energy expenditures and growth dilution explain higher PCB concentrations in male summer flounder

USGS Publications Warehouse

Madenjian, Charles P.; Jensen, Olaf P.; Rediske, Richard R.; O'Keefe, James P.; Vastano, Anthony R.; Pothoven, Steven A.

2016-01-01

Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes.

Differences in Energy Expenditures and Growth Dilution Explain Higher PCB Concentrations in Male Summer Flounder.

PubMed

Madenjian, Charles P; Jensen, Olaf P; Rediske, Richard R; O'Keefe, James P; Vastano, Anthony R; Pothoven, Steven A

2016-01-01

Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes.

Differences in Energy Expenditures and Growth Dilution Explain Higher PCB Concentrations in Male Summer Flounder

PubMed Central

Madenjian, Charles P.; Jensen, Olaf P.; Rediske, Richard R.; O’Keefe, James P.; Vastano, Anthony R.; Pothoven, Steven A.

2016-01-01

Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes. PMID:26794728

Oocyte cryopreservation for donor egg banking.

PubMed

Cobo, Ana; Remohí, José; Chang, Ching-Chien; Nagy, Zsolt Peter

2011-09-01

Oocyte donation is an efficient alternative to using own oocytes in IVF treatment for different indications. Unfortunately, 'traditional' (fresh) egg donations are challenged with inefficiency, difficulties of synchronization, very long waiting periods and lack of quarantine measures. Given the recent improvements in the efficiency of oocyte cryopreservation, it is reasonable to examine if egg donation through oocyte cryopreservation has merits. The objective of the current manuscript is to review existing literature on this topic and to report on the most recent outcomes from two established donor cryobank centres. Reports on egg donation using slow freezing are scarce and though results are encouraging, outcomes are not yet comparable to a fresh egg donation treatment. Vitrification on the other hand appears to provide high survival rates (90%) of donor oocytes and comparable fertilization, embryo development, implantation and pregnancy rates to traditional (fresh) egg donation. Besides the excellent outcomes, the ease of use for both donors and recipients, higher efficiency, lower cost and avoiding the problem of synchronization are all features associated with the benefit of a donor egg cryobank and makes it likely that this approach becomes the future standard of care. Oocyte donation is one of the last resorts in IVF treatment for couples challenged with infertility problems. However, traditional (fresh) egg donation, as it is performed today, is not very efficient, as typically all eggs from one donor are given to only one recipient, it is arduous as it requires an excellent synchronization between the donor and recipient and there are months or years of waiting time. Because of the development of an efficient oocyte cryopreservation technique, it is now possible to cryo-store donor (as well as non-donor) eggs, maintaining their viability and allowing their use whenever there is demand. Therefore, creating a donor oocyte cryobank would carry many advantages. In the present manuscript, the current experience with oocyte donation using cryopreservation technology is reviewed. The outcomes of two recently established donor egg cryobanks at Instituto Valenciano de Infertilidad in Spain and Reproductive Biology Associates in the USA (involving a large number of cases) demonstrate that egg cryo-survival is high and that fertilization, embryo development, implantation and pregnancy rates are similar to those reported after fresh egg donation. It also provides additional advantages of being more efficient, more economical, easier for both donors and recipients and potentially also safer, because eggs can now be quarantined for 6 months (or longer) to retest for infectious diseases in the donors. It is the opinion of the authors, based on several advantages associated with the use of donor egg cryobanking, that in the future there will be fewer traditional egg donations and increasingly more cryo-egg donations. Copyright © 2011 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

The Role of Wheat and Egg Constituents in the Formation of a Covalent and Non-covalent Protein Network in Fresh and Cooked Egg Noodles.

PubMed

Lambrecht, Marlies A; Rombouts, Ine; Nivelle, Mieke A; Delcour, Jan A

2017-01-01

Noodles of constant protein content and flour-to-egg protein ratio were made with whole egg, egg white, or egg yolk. The optimal cooking time, water absorption, and cooking loss of salted whole egg noodles was respectively lower and higher than of egg white and egg yolk noodles. However, cooked whole egg noodles showed the best Kieffer-rig extensibility. Differences in noodle properties were linked to protein network formation. Disulfide bonds in whole egg noodles developed faster and to a larger extent during cooking than in egg yolk noodles but slower and to a lower extent than in egg white noodles. The balance between the rate of protein cross-linking and starch swelling determines cooked noodle properties. Ionic and hydrophobic protein interactions increase the optimum cooking time and total work in Kieffer-rig extensibility testing of fresh noodles. Hydrogen bonds and covalent cross-links are probably the main determinants of the extensibility of cooked noodles. © 2016 Institute of Food Technologists®.

Oxygen Consumption is Limited at an Ecologically Relevant Rearing Temperature in Pupfish Eggs.

PubMed

Jones, Alexander C; Lim, David; Wayne-Thompson, Jacoby J; Urbina, Natasha; Puentedura, Georgina; Hillyard, Stanley; Breukelen, Frank Van

2016-10-01

The habitat of the critically endangered Devils Hole Pupfish, Cyprinodon diabolis is marked by constant high temperatures and low oxygen availability. In order to explore the effects of these conditions on development and recruitment of eggs in Devils Hole, we tested the effects of two ecologically relevant temperatures on the development, hatch success, and oxygen consumption of eggs from a refuge population of pupfish derived from C. diabolis and eggs from its close sister species, Cyprinodon nevadensis mionectes. We developed a simple method to measure oxygen consumption in a single egg. Parent acclimation temperature, rather than incubation temperature, was the most important factor influencing hatch success. Eggs incubated at 33°C hatched more quickly compared to those incubated at 28°C. Despite this accelerated development, larvae from both temperatures were of similar size at hatch. Unexpectedly, eggs incubated at 33°C experience lower than expected oxygen consumption rates compared to those incubated at 28°C. Oxygen consumption rates would be limited at PO 2 values that are much higher than environmental oxygen tensions. Oxygen consumption increased dramatically upon hatch, indicating that low oxygen conditions such as those present in Devils Hole may limit developing eggs. © 2016 Wiley Periodicals, Inc.

Genetic analysis of partial egg production records in Japanese quail using random regression models.

PubMed

Abou Khadiga, G; Mahmoud, B Y F; Farahat, G S; Emam, A M; El-Full, E A

2017-08-01

The main objectives of this study were to detect the most appropriate random regression model (RRM) to fit the data of monthly egg production in 2 lines (selected and control) of Japanese quail and to test the consistency of different criteria of model choice. Data from 1,200 female Japanese quails for the first 5 months of egg production from 4 consecutive generations of an egg line selected for egg production in the first month (EP1) was analyzed. Eight RRMs with different orders of Legendre polynomials were compared to determine the proper model for analysis. All criteria of model choice suggested that the adequate model included the second-order Legendre polynomials for fixed effects, and the third-order for additive genetic effects and permanent environmental effects. Predictive ability of the best model was the highest among all models (ρ = 0.987). According to the best model fitted to the data, estimates of heritability were relatively low to moderate (0.10 to 0.17) showed a descending pattern from the first to the fifth month of production. A similar pattern was observed for permanent environmental effects with greater estimates in the first (0.36) and second (0.23) months of production than heritability estimates. Genetic correlations between separate production periods were higher (0.18 to 0.93) than their phenotypic counterparts (0.15 to 0.87). The superiority of the selected line over the control was observed through significant (P < 0.05) linear contrast estimates. Significant (P < 0.05) estimates of covariate effect (age at sexual maturity) showed a decreased pattern with greater impact on egg production in earlier ages (first and second months) than later ones. A methodology based on random regression animal models can be recommended for genetic evaluation of egg production in Japanese quail. © 2017 Poultry Science Association Inc.

Short periods of incubation, egg turning during storage and broiler breeder hens age for early development of embryos, hatching results, chicks quality and juvenile growth.

PubMed

Damaziak, K; Paweska, M; Gozdowski, D; Niemiec, J

2018-05-14

An effect of modification of storage conditions of the eggs of broiler breeder flocks at the age of 49-, 52- and 70-, 73-wks of life on an early embryonic development, hatching time and synchronization, hatchability rates, chicks quality and broiler growth was investigated. The eggs were divided into 4 experimental groups: COI = eggs storage 5 d, at turning every 12 h; NSP = eggs storage 12 d, at turning every 12 h; SPIDES = were treated with 4 h pre-incubation at 30°C and 50-55% air humidity, delivered at 5 and 10 d over of 12 d of storage, and turning every 12 h; NCOI = eggs storage 12 d, no turning and no pre-incubation. Eggs from older hens were characterized by poorer hatchability and poorer chicks quality. The use of 2 × 4 h pre-incubation in 12 d of eggs storage could have an effect on the initial acceleration of embryonic development in eggs of young hens, contributing to the alignment of embryos development in eggs from young and older hens to 72 h of incubation. Pre-incubation had no effect on the length of incubation period, hatching window, but it increased the hatchability of the set and apparently fertilized eggs and decreased the number of eggs not hatched, and also improved chicks quality. Eggs turning by 90° every 12 h during the storage positively affected the embryonic development, shortening the incubation time and the quality of chicks, but had no effect on hatchability rates and body weight in 42 d of life. Based on the obtained results, it can be concluded that the applied modifications can be effective in counteracting the negative effects of storage of hatching eggs from both young and older birds.

Artificial propagation of the sea lamprey Petromyzon marinus

USGS Publications Warehouse

Lennon, Robert E.

1955-01-01

Observations on the gland products, gonads, and general characteristics of sexually mature sea lampreys, Petromyzon marinus (Linnaeus), from Lake Huron, and a need to obtain some information on very young larval lampreys, prompted an experiment on the stripping and hatching of eggs. Seventeen specimens were selected from a group of spawning migrants which had been trapped in the Ocqueoc River, Michigan, during June and held in live-cars in the lake until early August.

Effect of paternal blue catfish strain effects on hatchery fry production and performance of channel catfish X blue catfish F1 hybrid fry production and fingerling performance under commercial conditions

USDA-ARS?s Scientific Manuscript database

Four hundred four-year old mature Gold Kist strain channel catfish, Ictalurus punctatus were induced to spawn with 10 mg common carp pituitary extract (CPE) /kg BW in 8 spawning trials. The stripped eggs were fertilized with sperm of either D&B or Rio Grande blue catfish, I.furcatus to produce D&B ...

Assessment of lake sturgeon (Acipenser fulvescens) spawning efforts in the lower St. Clair River, Michigan

USGS Publications Warehouse

Nichols, S. Jerrine; Kennedy, Gregory; Crawford, Eric; Allen, Jeffrey; French, John; Black, Glen; Blouin, Marc; Hickey, James P.; Chernyak, Sergei; Haas, Robert; Thomas, Michael

2003-01-01

One of the most threatened remaining populations of lake sturgeon in the Great Lakes is found in the connecting channels between Lake Huron and Lake Erie. Only two spawning grounds are presently known to be active in this region, and both are in the St. Clair River. The spawning reef in the St. Clair River delta has been recently colonized by round gobies (Neogobius melanostomus) in densities up to 25/m2, raising concerns regarding predation on the benthic-oriented eggs and larvae of the sturgeon. Investigations in 1998–1999 showed that while round goby predation does occur, a number of other factors may be equally affecting sturgeon spawning success, including few spawning adults (< 60), suspected poaching pressure, low retention rate of eggs on the reef, low hatch rate (~0.5%), the presence of organic contaminants, and predation from native and exotic invertebrates and fish. Overall, we estimate that less than 1% of the eggs deposited during a spawning run survive to hatch. We were able to increase the egg hatch rate to 16% by placing eggs in predator-exclusion chambers on the reef. The fate of the larvae is uncertain. Two weeks after hatching, no larvae were found on the reef. We were unable to find them anywhere else in the river, nor was predation on larvae noted in either year. There were factors other than predation affecting larval survival in 1999. There was a higher silt load on the reef than in 1998 and large numbers of dead larvae were found. Recruitment success from this site could be improved by utilizing techniques to increase the number of eggs on the reef, such as reducing the illegal take of adult fish and by placing eggs in predator-exclusion chambers to increase hatch rate.

Effect of Egg Washing and Correlation between Eggshell Characteristics and Egg Penetration by Various Salmonella Typhimurium Strains

PubMed Central

Gole, Vaibhav C.; Chousalkar, Kapil K.; Roberts, Juliet R.; Sexton, Margaret; May, Damian; Tan, Jessica; Kiermeier, Andreas

2014-01-01

Salmonella is an important foodborne pathogen, causing an estimated 11,992 cases of infection in Australia per year. Egg or egg product related salmonellosis is a major concern for the egg industry. Worldwide, S. Typhimurium is one of the most common serovars identified in Salmonella food poisoning cases. The current study investigated the ability of five S. Typhimurium strains to penetrate washed and unwashed eggs using whole egg and agar egg penetration methods. All S. Typhimurium strains were able to penetrate eggshells and survive in egg albumen (at 20°C) according to whole egg penetration results. Polymerase Chain Reaction results demonstrated that S. Typhimurium strain 2 (103 and 105 CFU/mL), and strain 5 (103 and 105 CFU/mL) egg penetration was significantly higher (p<0.05) in washed eggs when compared to unwashed eggs. Statistical analysis of the agar penetration experiment indicated that S. Typhimurium was able to penetrate washed eggs at a significantly higher rate when compared to unwashed eggs (p<0.05). When compared to unwashed eggs, washed eggs also had significantly damaged cuticles. Statistical analysis also indicated that eggshell penetration by S. Typhimurium was related to various eggshell ultrastructural features such as cap quality, alignment, erosion, confluence, Type B bodies and cuticle cover. PMID:24621821

Effects of HMX exposure upon metabolic rate of northern bobwhite quail (Colinus virginianus) in ovo.

PubMed

Liu, Jun; Cox, Stephen B; Beall, Blake; Brunjes, Kristina J; Pan, Xiaoping; Kendall, Ronald J; Anderson, Todd A; McMurry, Scott T; Cobb, George P; Smith, Philip N

2008-05-01

We evaluated the use of the gas exchange rate as an ecologically relevant indicator of chemical stress in avian embryos/eggs. Northern bobwhite quail (Colinus virginianus) were exposed to octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) via feed containing nominal concentrations of 0, 12.5, 50.0, and 125.0 mg kg(-1). Metabolic rates (oxygen consumption) of developing quail eggs were then measured via respirometry to examine potential effects of HMX exposure. Metabolic rates were examined on 5, 9, and 21 d of incubation. Next, concentrations of HMX in embryos/eggs were determined by liquid chromatography-mass spectrometry. Mean (+/-SE) concentrations of HMX in eggs were 21.0+/-5.9, 1113+/-79.0, 3864+/-154.0, and 7426+/-301.1 ng g(-1) in control, low, medium and high dose groups, respectively. There were significant differences in oxygen consumption among the three embryo ages, however differences among the ages were not consistent among dose groups (age x dose group interaction p<0.0001). Oxygen consumption rates did not vary as a function of HMX in embryos (p=0.18). No evidence was observed for alterations of in ovo metabolic rates associated with HMX exposure.

Hatchability tests with eggs from captive wood ducks

USGS Publications Warehouse

Doty, H.A.

1972-01-01

The effect of diet and artificial incubation on fertility and hatchability of wood duck (Aix sponsa) eggs and survival of young was measured. Hatchability of eggs from hens fed a diet containing 37 percent protein was increased significantly (P <0.05) over that of hens fed a diet containing 17 percent protein. Hatchability was also significantly (P<0.005) greater for eggs incubated 10 days under hens before being placed in an incubator than for eggs placed in an incubator for the entire period. Ducklings that hatched from naturally started incubation survived at a much higher rate (P<0.001). Egg fertility was not affected by the diets.

Molluscicidal activities of aqueous extract of the sea anemone Parasicyonis actinostoloides against vector snails Bulinus truncatus and Lymnaea natalensis.

PubMed

el-Sayed, Kamelia Abass

2006-08-01

The aqueous extract of the sea anemone Parasicyonis actinostoloides showed molluscicidal effect against vector snails of Schistosoma hacematobium and Fasciola gigantica after 24 hours of exposure. LC50) and LC90 values for P. actinostoloides were 40 & 78.6 ppm for B. runcatus and 46.6 & 86.5 ppm for L. natalensis respectively. The effect of continuously exposure of B. truncatits and L. naltlensis to sublethal aqueous extract concentrations (LC0, LC10 & LC25) on survival rate, egg production and on infectivity of miracidia to infection with S. haematobium and F. gigantica were studied. The data showed that no B. truncatus survived more than 42, 32 & 27 days after exposure with a mean life span of 18.5, 13.3 & 11.1 days respectively. The death rate of B. truncatus with LC0 was highly significant as compared to treatment with LC10 & LC25 (p < 0.01). L. natalensis were more susceptible to the effect of aqueous extract than B. truncatus. LC0, LC10 & LC25, extract killed all L. natalensis through 32, 27 & 22 days. The mean life span of those exposed to LC0 was 12.37 days, high significant when compared with treated LC10 & LC25 ones (p < 0.01). The cumulative mortality rates of B. truncatus and L. natalensis in controls during the experimental study (52 days) was 60% & 75%, respectively. Egg production of B. truncatius and L. natalensis was not affected by sublethal concentrations. Control snails layed significantly higher no. of eggs than treated ones. B. truncatus stopped egg laying 17 days after exposure to LC25. those treated with LC10 & LC0 ceased to deposit eggs after 22 & 27 days respectively. The percent reduction in egg laying capacity of B. truncatus treated with LC0, LC10 & LC25 compared to controls was 77.1%, 93.2% & 92.8% respectively (p < 0.01). Similar reduction in egg production of treated L. natalensis cornpared to controls occurred, the percent reduction in egg production of snails treated with LC0, LC10 & LC25 in relation to controls was 78.4%, 92.4% & 94.7% respectively. Sublethal concentrations of aqueous extract of P. actinostoloides affected hatchability of B. truncatus and L. natalensis eggs. The data showed that eggs of B. truncatus and L. natalensis can hatch in all tested concentrations but with different rates. The eggs' hatchability in snails exposed to LC0, LCIo & LC25 extract at 5 days old was 44%, 38% & 30% in B. truncatus respectively. In L. natalensis eggs, the corresponding rates were lower 28%, 24% & 18% respectively. The infection of B. truncatuts and L. natalensis with S. haematobium n and F. giganlica miracidia was greatly reduced by the sublethal concentrations of aqueous extract of P. actinostoloides. The reduction of infection rate increased with the increased of sublethal concentrations. In B. truncatus the reduction was 43.2%, 57.6% & 76.6% compared to controls and in L. natalensis was 56.3%, 70.2% & 77.4%, respectively.

DECOUPLING OF PROTEIN AND RNA SYNTHESIS DURING DEUTERIUM PARTHENOGENESIS IN SEA URCHIN EGGS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gross, P.R.; Spindel, W.; Cousineau, G.H.

1963-10-29

The parthenogenetic activation of cell division and suppression of nucleic acid synthesis by deuterium in eggs of sea urchins was investigated. D/ sub 2/O treatment was found to evoke a high rate of protein synthesis in the eggs that was maintained for several hours. However, eggs whose protein synthesis was activated and that were making labeled cytasters showed no increment in RNA synthesis over controls. (P.C.H.)

Methylxanthines and reproduction.

PubMed

Minelli, Alba; Bellezza, Ilaria

2011-01-01

Reproduction is the process by which organisms create descendants. In human reproduction, two kinds of sex cells, or gametes, are involved. Sperm, the male gamete, and egg egg , or ovum ovum Vedi egg , the female gamete, must meet in the female reproductive system to create a new individual and both the female and the male reproductive systems are essential to the occurrence of reproduction. Scientific reports dealing with the effects of methylxanthines on reproduction are mostly centred on the use of these compounds as phosphodiesterase inhibitors that, by maintaining high intracellular levels of cyclic AMP (cAMP) cyclic AMP , will affect the gametes differently. High cAMP levels will sustain sperm sperm maturation while they hold the oocytes in mitotic arrest. Caffeine caffeine , being the methylxanthine most widely consumed by every segment of the population, has been the subject of greatest interest among health professionals and researchers. Conflicting results still seem to characterize the association between male/female caffeine caffeine consumption in adult life and semen quality/fertility fertility , although moderate daily caffeine consumption of levels up to 400-450 mg/day (5.7-6.4 mg/kg/day in a 70-kg adult) do not seem to be associated with adverse effects, i.e. general toxicity, effects on bone status and calcium balance, cardiovascular effects, behavioural changes, increased incidence of cancer, or effects on male fertility. A clear stimulation of egg-laying by the coffee leaf pest Leucoptera coffeella was recently reported, providing support for the hypothesis that caffeine, in a dose-dependent way, in insects stimulates egg-laying, thus leading to the death of coffee trees.

Multiple Mating, Paternity and Complex Fertilisation Patterns in the Chokka Squid Loligo reynaudii

PubMed Central

Naud, Marie-Jose; Sauer, Warwick H. H.; McKeown, Niall J.; Shaw, Paul W.

2016-01-01

Polyandry is widespread and influences patterns of sexual selection, with implications for sexual conflict over mating. Assessing sperm precedence patterns is a first step towards understanding sperm competition within a female and elucidating the roles of male- and female-controlled factors. In this study behavioural field data and genetic data were combined to investigate polyandry in the chokka squid Loligo reynaudii. Microsatellite DNA-based paternity analysis revealed multiple paternity to be the norm, with 79% of broods sired by at least two males. Genetic data also determined that the male who was guarding the female at the moment of sampling was a sire in 81% of the families tested, highlighting mate guarding as a successful male tactic with postcopulatory benefits linked to sperm deposition site giving privileged access to extruded egg strings. As females lay multiple eggs in capsules (egg strings) wherein their position is not altered during maturation it is possible to describe the spatial / temporal sequence of fertilisation / sperm precedence There were four different patterns of fertilisation found among the tested egg strings: 1) unique sire; 2) dominant sire, with one or more rare sires; 3) randomly mixed paternity (two or more sires); and 4) a distinct switch in paternity occurring along the egg string. The latter pattern cannot be explained by a random use of stored sperm, and suggests postcopulatory female sperm choice. Collectively the data indicate multiple levels of male- and female-controlled influences on sperm precedence, and highlights squid as interesting models to study the interplay between sexual and natural selection. PMID:26872354

Thermal plasticity in life-history traits in the polymorphic blue-tailed damselfly, Ischnura elegans: no differences between female morphs.

PubMed

Bouton, Niels; Iserbyt, Arne; Van Gossum, Hans

2011-01-01

Female polymorphism is observed in various animal species, but is particularly common in damselflies. The maintenance of this polymorphism has traditionally been explained from frequency and density dependent sexual conflict, however, the role of abiotic factors has recently attracted more interest. Here, the role of ambient temperature in shaping life-history was investigated for the three female morphs of Ischnura elegans (Vander Linden) (Zygoptera: Coenagrionidae). Eggs were obtained from the three mature female morphs for two populations in the Netherlands. Using a split-brood design, eggs of both populations were divided between a cold and a warm treatment group in the laboratory, and egg survival and hatching time were measured. Significant thermal plasticity was found in both hatching time and egg survival between both temperature treatments. However, individuals born to mothers belonging to different colour morphs did not differ in their response to temperature treatment. Independent of colour morph, clear differences in both life-history traits between the populations were found, suggesting local adaptation. Specifically, individuals from one population hatched faster but had lower egg survival in both thermal regimes. The selection force establishing fast hatching could be (facultative) bivoltinism in one of the populations compared to univoltinism in the other. This would be in line with the more southern (and more coastal) location of the presumed bivoltine population and the inverse relation between voltinism and latitude known from earlier studies. However, other natural selection forces, e.g. deterioration of the aquatic habitat, may also drive fast hatching.