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Sample records for carcinus maenas genetic

  1. Temporal genetic homogeneity among shore crab (Carcinus maenas) larval events supplied to an estuarine system on the Portuguese northwest coast.

    PubMed

    Domingues, C P; Creer, S; Taylor, M I; Queiroga, H; Carvalho, G R

    2011-05-01

    Despite the importance of larval biology in the life histories of many marine animals, relatively little information exists on the dynamics and genetic composition of larval cohorts. The supply of megalopae larvae of the shore crab, Carcinus maenas, was measured on a daily basis during 8 months spread along two larval periods (2006 and 2007) at the Ria de Aveiro estuary, on the Portuguese northwest coast. A total of 10 microsatellite DNA loci were employed to explore the genetic structure, variability and relatedness of temporally distinct megalopal events, selected from the major pulses of supply. Larval variation was also compared genetically with that of a previously studied adult crabs sample, at the same loci, collected in 2006 and 2007 along the Iberian Peninsula. Results revealed a lack of genetic differentiation and identical diversity levels among larval events over time. No evidence of reduced genetic diversity between megalopae relative to the diversity assessed from the pooled sample of adults was found. Moreover, there was no evidence of any family relatedness among larvae from temporal events. The results obtained for C. maenas contradict predictions made by the sweepstakes reproduction hypothesis, in which large variance in reproductive success is expected, which is presumably detectable as sharp genetic discontinuities among separate larval events. Data here indicate conversely a high degree of temporal genetic stability among larval supply to a given estuary under variable oceanographic conditions, consistent with the hypothesis that sampled larvae were drawn from a large number of adults that do not differ in reproductive success.

  2. Temporal genetic homogeneity among shore crab (Carcinus maenas) larval events supplied to an estuarine system on the Portuguese northwest coast

    PubMed Central

    Domingues, C P; Creer, S; Taylor, M I; Queiroga, H; Carvalho, G R

    2011-01-01

    Despite the importance of larval biology in the life histories of many marine animals, relatively little information exists on the dynamics and genetic composition of larval cohorts. The supply of megalopae larvae of the shore crab, Carcinus maenas, was measured on a daily basis during 8 months spread along two larval periods (2006 and 2007) at the Ria de Aveiro estuary, on the Portuguese northwest coast. A total of 10 microsatellite DNA loci were employed to explore the genetic structure, variability and relatedness of temporally distinct megalopal events, selected from the major pulses of supply. Larval variation was also compared genetically with that of a previously studied adult crabs sample, at the same loci, collected in 2006 and 2007 along the Iberian Peninsula. Results revealed a lack of genetic differentiation and identical diversity levels among larval events over time. No evidence of reduced genetic diversity between megalopae relative to the diversity assessed from the pooled sample of adults was found. Moreover, there was no evidence of any family relatedness among larvae from temporal events. The results obtained for C. maenas contradict predictions made by the sweepstakes reproduction hypothesis, in which large variance in reproductive success is expected, which is presumably detectable as sharp genetic discontinuities among separate larval events. Data here indicate conversely a high degree of temporal genetic stability among larval supply to a given estuary under variable oceanographic conditions, consistent with the hypothesis that sampled larvae were drawn from a large number of adults that do not differ in reproductive success. PMID:20959862

  3. CHARACTERIZATION OF MICROSATELLITE LOCI IN THE EUROPEAN GREEN CRAB (CARCINUS MAENAS)

    EPA Science Inventory

    Carcinus maenas (Decapoda: Portunidae) has proven a highly successful invasive marine species whose potential economic and ecological impacts are of great concern worldwide. Here, we characterize fourteen polymorphic microsatellite loci in C. maenas and its sister species C. Ae...

  4. More than one way to invade: lessons from genetic studies of Carcinus shore crabs

    EPA Science Inventory

    The European green crab Carcinus maenas is one of the world's most widely recognized marine invaders. The success of this species has provided opportunities to explore genetic patterns associated with establishment and population expansion following independent introduction event...

  5. Predator prey size relationship between Pseudopleuronectes americanus and Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Fairchild, E. A.; Howell, W. H.

    2000-10-01

    Young-of-year flatfish grow through a series of critical periods in which they are vulnerable to different predators, including decapod crustaceans. The purpose of this study was to determine if winter flounder, Pseudopleuronectes americanus, were vulnerable to one such decapod, the green crab, Carcinus maenas, and to determine if vulnerability differed between wild and cultured fish. To examine the predator-prey size relationship, an experiment was conducted in which six cultured and three wild winter flounder size class treatments were tested against six crab size class treatments. Flounder of all size classes were preyed on by all size classes of green crabs; however, mortality was highest when the largest crabs were matched with the smallest flounder. The number of flounder killed per day was significantly higher (31%) in winter flounder <20 mm compared to all other larger fish size classes (4-8%). Additionally, these fish were attacked at a faster rate than any other fish size class. For the 31-60 mm fish size classes tested, more wild fish (11%) were killed per day by crabs than cultured fish (6.3%). These results suggest that in a winter flounder stock enhancement program, only fish >20 mm should be released to promote post-release survival.

  6. Biological impacts of enhanced alkalinity in Carcinus maenas.

    PubMed

    Cripps, Gemma; Widdicombe, Stephen; Spicer, John I; Findlay, Helen S

    2013-06-15

    Further steps are needed to establish feasible alleviation strategies that are able to reduce the impacts of ocean acidification, whilst ensuring minimal biological side-effects in the process. Whilst there is a growing body of literature on the biological impacts of many other carbon dioxide reduction techniques, seemingly little is known about enhanced alkalinity. For this reason, we investigated the potential physiological impacts of using chemical sequestration as an alleviation strategy. In a controlled experiment, Carcinus maenas were acutely exposed to concentrations of Ca(OH)2 that would be required to reverse the decline in ocean surface pH and return it to pre-industrial levels. Acute exposure significantly affected all individuals' acid-base balance resulting in slight respiratory alkalosis and hyperkalemia, which was strongest in mature females. Although the trigger for both of these responses is currently unclear, this study has shown that alkalinity addition does alter acid-base balance in this comparatively robust crustacean species. PMID:23602261

  7. Green Crab (Carcinus maenas) Foraging Efficiency Reduced by Fast Flows

    PubMed Central

    Robinson, Elizabeth M.; Smee, Delbert L.; Trussell, Geoffrey C.

    2011-01-01

    Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is invading marine habitats throughout the world. High flow velocities are known to reduce green crab predation rates and our study sought to identify the mechanisms by which flow affects green crabs. We performed a series of experiments with green crabs to determine: 1) if their ability to find prey was altered by flow in the field, 2) how flow velocity influenced their foraging efficiency, and 3) how flow velocity affected their handling time of prey. In a field study, we caught significantly fewer crabs in baited traps at sites with fast versus slow flows even though crabs were more abundant in high flow areas. This finding suggests that higher velocity flows impair the ability of green crabs to locate prey. In laboratory flume assays, green crabs foraged less efficiently when flow velocity was increased. Moreover, green crabs required significantly more time to consume prey in high velocity flows. Our data indicate that flow can impose significant chemosensory and physical constraints on green crabs. Hence, hydrodynamics may strongly influence the role that green crabs and other predators play in rocky intertidal communities. PMID:21687742

  8. Genetic patterns across multiple introductions of the globally invasive crab genus Carcinus

    EPA Science Inventory

    The European green crab Carcinus maenas is one of the world's most successful aquatic invaders, having established populations on every continent with temperate shores. Here we describe patterns of genetic diversity across both the native and introduced ranges of C. maenas and it...

  9. GREEN CRAB (CARCINUS MAENAS LINNAEUS) CONSUMPTION RATES ON AND PREY PREFERENCES AMONG FOUR BIVALVE PREY SPECIES

    EPA Science Inventory

    The European green crab, Carcinus maenas, is a recent invader to Pacific Northwest (PNW) estuaries with a voracious appetite, especially for bivalves. To assess their potential impact, we estimated green crab consumption rates on four PNW bivalve species, Yaquina oyster (Ostrea ...

  10. Crabs in Labs: The Shore Crab (Carcinus maenas) as Teaching Material.

    ERIC Educational Resources Information Center

    Hogarth, P. J.

    1983-01-01

    The shore crab (Carcinus maenas) is an excellent subject for school study, both in the field and the laboratory. It is easily collected and maintained and can be used for a wide range of investigations. Some background details are given and possible areas of investigation suggested. (Author)

  11. Bioenergetics modeling to investigate habitat use by the non-indigenous crab, Carcinus maenas, in Willapa Bay, Washington, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A bioenergetics model was developed and applied to questions of habitat use and migration behavior of non-indigenous European green crab (Carcinus maenas) in Willapa Bay, Washington, USA. The model was parameterized using existing data from published studies on the ecology and physiology of C. maena...

  12. A Membrane-bound Hemoglobin from Gills of the Green Shore Crab Carcinus maenas*

    PubMed Central

    Ertas, Beyhan; Kiger, Laurent; Blank, Miriam; Marden, Michael C.; Burmester, Thorsten

    2011-01-01

    Most hemoglobins serve for the transport or storage of O2. Although hemoglobins are widespread in “entomostracan” Crustacea, malacostracans harbor the copper-containing hemocyanin in their hemolymph. Usually, only one type of respiratory protein occurs within a single species. Here, we report the identification of a hemoglobin of the shore crab Carcinus maenas (Malacostraca, Brachyura). In contrast to the dodecameric hemocyanin of this species, C. maenas hemoglobin does not reside in the hemolymph but is restricted to the gills. Immunofluorescence studies and cell fractioning showed that C. maenas hemoglobin resides in the membrane of the chief cells of the gill. To the best of our knowledge, this is the first time that a membrane-bound hemoglobin has been identified in eukaryotes. Bioinformatic evaluation suggests that C. maenas hemoglobin is anchored in the membrane by N-myristoylation. Recombinant C. maenas hemoglobin has a hexacoordinate binding scheme at the Fe2+ and an oxygen affinity of P50 = 0.5 Torr. A rapid autoxidation rate precludes a function as oxygen carrier. We rather speculate that, analogous to prokaryotic membrane-globins, C. maenas hemoglobin carries out enzymatic functions to protect the lipids in cell membrane from reactive oxygen species. Sequence comparisons and phylogenetic studies suggested that the ancestral arthropod hemoglobin was most likely an N-myristoylated protein that did not have an O2 supply function. True respiratory hemoglobins of arthropods, however, evolved independently in chironomid midges and branchiopod crustaceans. PMID:21118803

  13. Methodical aspects of rearing decapod larvae, Pagurus bernhardus (Paguridae) and Carcinus maenas (Portunidae)

    NASA Astrophysics Data System (ADS)

    Dawirs, R. R.

    1982-12-01

    Improved methods for experimental rearing of Pagurus bernhardus and Carcinus maenas larvae are presented. Isolated maintenance was found essential for reliable statistical evaluation of results obtained from stages older than zoea-1. Only by isolated rearing is it possible to calculate mean values ±95% confidence intervals of stage duration. Mean values (without confidence intervals) can only be given for group-reared larvae if mortality is zero. Compared to group rearing, isolated rearing led to better survival, shorter periods of development and stimulated growth. Due to different swimming behavior P. bernhardus zoeae needed larger water volumes than Carcinus maenas larvae. P. bernhardus zoeae were reared with best results when isolated in Petri dishes (ca. 50 ml). They fed on newly hatched brine shrimp nauplii ( Artemia spp.). P. bernhardus megalopa did not require any gastropod shell or substratum; it developed best in glass vials without any food. C. maenas larvae could be reared most sucessfully in glass vials (ca 20 ml) under a simulated day-night regime (LD 16:8); constant darkness had a detrimental effect on development, leading to prolonged stage-duration times. C. maenas larvae were fed a mixture of newly hatched brine shrimp naupli and rotifers ( Brachionus plicatilis).

  14. Expansion of the neuropeptidome of the globally invasive marine crab Carcinus maenas.

    PubMed

    Christie, Andrew E

    2016-09-01

    Carcinus maenas is widely recognized as one of the world's most successful marine invasive species; its success as an invader is due largely to its ability to thrive under varied environmental conditions. The physiological/behavioral control systems that allow C. maenas to adapt to new environments are undoubtedly under hormonal control, the largest single class of hormones being peptides. While numerous studies have focused on identifying native C. maenas peptides, none has taken advantage of mining transcriptome shotgun assembly (TSA) sequence data, a strategy proven highly successful for peptide discovery in other crustaceans. Here, a C. maenas peptidome was predicted via in silico transcriptome mining. Thirty-seven peptide families were searched for in the extant TSA database, with transcripts encoding precursors for 29 groups identified. The pre/preprohormones deduced from the identified sequences allowed for the prediction of 263 distinct mature peptides, 193 of which are new discoveries for C. maenas. The predicted peptides include isoforms of adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin B, allatostatin C, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone, diuretic hormone 31, diuretic hormone 44, eclosion hormone, FMRFamide-like peptide, HIGSLYRamide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, proctolin, pyrokinin, red pigment concentrating hormone, RYamide, short neuropeptide F, SIFamide, and tachykinin-related peptide. This peptidome is the largest predicted from any single crustacean using the in silico approach, and provides a platform for investigating peptidergic signaling in C. maenas, including control of the processes that allow for its success as a global marine invader. PMID:27179880

  15. Are genes faster than crabs? Mitochondrial introgression exceeds larval dispersal during population expansion of the invasive crab Carcinus maenas

    PubMed Central

    Darling, John A.; Tsai, Yi-Hsin Erica; Blakeslee, April M. H.; Roman, Joe

    2014-01-01

    Biological invasions offer unique opportunities to investigate evolutionary dynamics at the peripheries of expanding populations. Here, we examine genetic patterns associated with admixture between two distinct invasive lineages of the European green crab, Carcinus maenas L., independently introduced to the northwest Atlantic. Previous investigations based on mitochondrial DNA sequences demonstrated that larval dispersal driven by advective currents could explain observed southward displacement of an admixture zone between the two invasions. Comparison of published mitochondrial results with new nuclear data from nine microsatellite loci, however, reveals striking discordance in their introgression patterns. Specifically, introgression of mitochondrial genomes relative to nuclear background suggests that demographic processes such as sex-biased reproductive dynamics and population size imbalances—and not solely larval dispersal—play an important role in driving the evolution of the genetic cline. In particular, the unpredicted introgression of mitochondrial alleles against the direction of mean larval dispersal in the region is consistent with recent models invoking similar demographic processes to explain movements of genes into invading populations. These observations have important implications for understanding historical shifts in C. maenas range limits, and more generally for inferences of larval dispersal based on genetic data. PMID:26064543

  16. Are genes faster than crabs? Mitochondrial introgression exceeds larval dispersal during population expansion of the invasive crab Carcinus maenas.

    PubMed

    Darling, John A; Tsai, Yi-Hsin Erica; Blakeslee, April M H; Roman, Joe

    2014-10-01

    Biological invasions offer unique opportunities to investigate evolutionary dynamics at the peripheries of expanding populations. Here, we examine genetic patterns associated with admixture between two distinct invasive lineages of the European green crab, Carcinus maenas L., independently introduced to the northwest Atlantic. Previous investigations based on mitochondrial DNA sequences demonstrated that larval dispersal driven by advective currents could explain observed southward displacement of an admixture zone between the two invasions. Comparison of published mitochondrial results with new nuclear data from nine microsatellite loci, however, reveals striking discordance in their introgression patterns. Specifically, introgression of mitochondrial genomes relative to nuclear background suggests that demographic processes such as sex-biased reproductive dynamics and population size imbalances-and not solely larval dispersal-play an important role in driving the evolution of the genetic cline. In particular, the unpredicted introgression of mitochondrial alleles against the direction of mean larval dispersal in the region is consistent with recent models invoking similar demographic processes to explain movements of genes into invading populations. These observations have important implications for understanding historical shifts in C. maenas range limits, and more generally for inferences of larval dispersal based on genetic data. PMID:26064543

  17. The crab Carcinus maenas as a suitable experimental model in ecotoxicology.

    PubMed

    Rodrigues, Elsa Teresa; Pardal, Miguel Ângelo

    2014-09-01

    Aquatic ecotoxicology broadly focuses on how aquatic organisms interact with pollutants in their environment in order to determine environmental hazard and potential risks to humans. Research has produced increasing evidence on the pivotal role of aquatic invertebrates in the assessment of the impact of pollutants on the environment. Its potential use to replace fish bioassays, which offers ethical advantages, has already been widely studied. Nevertheless, the selection of adequate invertebrate experimental models, appropriate experimental designs and bioassays, as well as the control of potential confounding factors in toxicity testing are of major importance to obtain scientifically valid results. Therefore, the present study reviews more than four decades of published research papers in which the Green crab Carcinus maenas was used as an experimental test organism. In general, the surveyed literature indicates that C. maenas is sensitive to a wide range of aquatic pollutants and that its biological responses are linked to exposure concentrations or doses. Current scientific knowledge regarding the biology and ecology of C. maenas and the extensive studies on toxicology found for the present review recognise the Green crab as a reliable estuarine/marine model for routine testing in ecotoxicology research and environmental quality assessment, especially in what concerns the application of the biomarker approach. Data gathered provide valuable information for the selection of adequate and trustworthy bioassays to be used in C. maenas toxicity testing. Since the final expression of high quality testing is a reliable outcome, the present review recommends gender, size and morphotype separation in C. maenas experimental designs and data evaluation. Moreover, the organisms' nutritional status should be taken into account, especially in long-term studies. Studies should also consider the crabs' resilience when facing historical and concurrent contamination. Finally

  18. The crab Carcinus maenas as a suitable experimental model in ecotoxicology.

    PubMed

    Rodrigues, Elsa Teresa; Pardal, Miguel Ângelo

    2014-09-01

    Aquatic ecotoxicology broadly focuses on how aquatic organisms interact with pollutants in their environment in order to determine environmental hazard and potential risks to humans. Research has produced increasing evidence on the pivotal role of aquatic invertebrates in the assessment of the impact of pollutants on the environment. Its potential use to replace fish bioassays, which offers ethical advantages, has already been widely studied. Nevertheless, the selection of adequate invertebrate experimental models, appropriate experimental designs and bioassays, as well as the control of potential confounding factors in toxicity testing are of major importance to obtain scientifically valid results. Therefore, the present study reviews more than four decades of published research papers in which the Green crab Carcinus maenas was used as an experimental test organism. In general, the surveyed literature indicates that C. maenas is sensitive to a wide range of aquatic pollutants and that its biological responses are linked to exposure concentrations or doses. Current scientific knowledge regarding the biology and ecology of C. maenas and the extensive studies on toxicology found for the present review recognise the Green crab as a reliable estuarine/marine model for routine testing in ecotoxicology research and environmental quality assessment, especially in what concerns the application of the biomarker approach. Data gathered provide valuable information for the selection of adequate and trustworthy bioassays to be used in C. maenas toxicity testing. Since the final expression of high quality testing is a reliable outcome, the present review recommends gender, size and morphotype separation in C. maenas experimental designs and data evaluation. Moreover, the organisms' nutritional status should be taken into account, especially in long-term studies. Studies should also consider the crabs' resilience when facing historical and concurrent contamination. Finally

  19. The role of the transbranchial potential difference in hyperosmotic regulation of the shore crab Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Winkler, Andreas

    1986-03-01

    When isolated gills of the shore crab Carcinus maenas were bathed and perfused with identical solutions on both sides (50 % sea water), a spontaneous transepithelial potential difference (PD) of some millivolts (hemolymph side negative) was established. This PD is of active nature and requires the metabolism of the living cell, since it uses its own sources of energy in addition to organic nutrients offered in the flow of artificial hemolymph. Addition of sodium cyanide and dinitrophenole to bathing and perfusion medium resulted in reversible breakdown of PDs in a concentration-dependent mode. In posterior gills of C. maenas, the potential differences were more negative compared to data measured in anterior gills of the same individuals. These results are correlated with higher specific activities of Na-K-ATPase in posterior gills. Experiments with triamterene indicate that sodium uptake in C. maenas is sensitive to this diuretic drug, when applied on the apical side of the epithelial cell. The results obtained show that active uptake of sodium from medium to blood across the gills is performed by a complex mechanism including participation of several basal and apical transport steps.

  20. Physiological responses to digestion in low salinity in the crabs Carcinus maenas and Cancer irroratus.

    PubMed

    Penney, Chantelle M; Patton, Richard L; Whiteley, Nia M; Driedzic, William R; McGaw, Iain J

    2016-01-01

    Osmoregulation and digestion are energetically demanding, and crabs that move into low salinity environments to feed must be able to balance the demands of both processes. Achieving this balance may pose greater challenges for weak than for efficient osmoregulators. This study examined the rate of oxygen consumption (MO2) of Carcinus maenas (efficient osmoregulator) and Cancer irroratus (weak osmoregulator) as a function of feeding and hyposaline stress. The MO2 increased 2-fold in both species following feeding. The MO2 increased and remained elevated in fasted crabs during acute hyposaline exposure. When hyposaline stress occurred after feeding, C. maenas responded with an immediate summation of the MO2 associated with feeding and hyposaline stress, whereas C. irroratus reacted with a partial summation of responses in a salinity of 24‰, but were unable to sum responses in 16‰. C. irroratus exhibited longer gut transit times. This may be due to an inability to regulate osmotic water onload as efficiently as C. maenas. Mechanical digestion in crabs can account for a significant portion of SDA, and a short term interruption led to the delay in summation of metabolic demands. Although protein synthesis is reported to account for the majority of SDA, this did not appear to be the case here. Protein synthesis rates were higher in C. irroratus but neither feeding or salinity affected protein synthesis rates of either species which suggests that protein synthesis can continue in low salinity as long as substrates are available.

  1. Physiological responses to digestion in low salinity in the crabs Carcinus maenas and Cancer irroratus.

    PubMed

    Penney, Chantelle M; Patton, Richard L; Whiteley, Nia M; Driedzic, William R; McGaw, Iain J

    2016-01-01

    Osmoregulation and digestion are energetically demanding, and crabs that move into low salinity environments to feed must be able to balance the demands of both processes. Achieving this balance may pose greater challenges for weak than for efficient osmoregulators. This study examined the rate of oxygen consumption (MO2) of Carcinus maenas (efficient osmoregulator) and Cancer irroratus (weak osmoregulator) as a function of feeding and hyposaline stress. The MO2 increased 2-fold in both species following feeding. The MO2 increased and remained elevated in fasted crabs during acute hyposaline exposure. When hyposaline stress occurred after feeding, C. maenas responded with an immediate summation of the MO2 associated with feeding and hyposaline stress, whereas C. irroratus reacted with a partial summation of responses in a salinity of 24‰, but were unable to sum responses in 16‰. C. irroratus exhibited longer gut transit times. This may be due to an inability to regulate osmotic water onload as efficiently as C. maenas. Mechanical digestion in crabs can account for a significant portion of SDA, and a short term interruption led to the delay in summation of metabolic demands. Although protein synthesis is reported to account for the majority of SDA, this did not appear to be the case here. Protein synthesis rates were higher in C. irroratus but neither feeding or salinity affected protein synthesis rates of either species which suggests that protein synthesis can continue in low salinity as long as substrates are available. PMID:26459987

  2. Involvement of the antioxidant system in differential sensitivity of Carcinus maenas to fenitrothion exposure.

    PubMed

    Rodrigues, A P; Gravato, C; Guimarães, L

    2013-10-01

    Carcinus maenas is an invertebrate with worldwide distribution and high ability to adapt to different environments, which is frequently used in environmental monitoring. Despite this, it is not clear how historical exposure to moderate contamination may influence sensitivity to further chemical stress in this important decapod species. This study investigated differential responses to organophosphate fenitrothion of C. maenas from a moderately contaminated estuary and a low impacted one, using in vitro and in vivo biomarker assays. To clarify potential differences in sensitivity, a biochemical characterisation of muscle cholinesterases was first performed. The results indicated acetylcholinesterase (AChE) as the main form present in C. maenas muscle. Exposure assays revealed that crabs from the moderately contaminated site were less sensitive to fenitrothion showing lower AChE inhibition than those from the low impacted site. Other biomarker changes detected in these animals were: increased anaerobic metabolism (muscle lactate dehydrogenase), enhanced phase II biotransformation (glutathione S-transferases in the digestive gland) and antioxidant defences (i.e., activities of glutathione reductase, glutathione peroxidase and catalase, and levels of total glutathiones in the digestive gland). Altogether, the results pointed out a role for the glutathione redox system towards tolerance to fenitrothion exposure. PMID:24056931

  3. Competition and niche segregation following the arrival of Hemigrapsus takanoi in the formerly Carcinus maenas dominated Dutch delta

    NASA Astrophysics Data System (ADS)

    van den Brink, A. M.; Wijnhoven, S.; McLay, C. L.

    2012-10-01

    In a combined study including a 20 year monitoring programme of the benthic communities of four Dutch delta waters and a snapshot survey conducted in the Oosterschelde tidal bay in 2011, the populations of the native portunid European shore crab Carcinus maenas and the introduced varunid crabs Hemigrapsus takanoi and Hemigrapsus sanguineus were investigated. Whereas C. maenas was the most common shore crab in these waters, its numbers have declined on the soft sediment substrates during the last 20 years. As the two exotic crab species were first recorded in the Dutch delta in 1999, they could not have initiated the decline of the native C. maenas. However, within a few years H. takanoi completely dominated the intertidal hard substrate environments; the same environments on which juvenile C. maenas depend. On soft sediment substrate the native and exotic shore crab species are presently more or less equally abundant. H. takanoi might initially have taken advantage of the fact that C. maenas numbers were declining. Additionally H. takanoi are thriving in expanding oyster reefs of Crassostrea gigas (Pacific oyster) in the Dutch delta waters, which provide new habitat. Nowadays H. takanoi appears to be a fierce interference competitor or predator for small C. maenas specimens by expelling them from their shelters. These interactions have led to increased mortality of juvenile C. maenas. At present the C. maenas populations seem to be maintained by crabs that survive and reproduce on available soft sediment habitats where H. takanoi densities are low.

  4. Comparing quality of estuarine and nearshore intertidal habitats for Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Amaral, Valter; Cabral, Henrique N.; Jenkins, Stuart; Hawkins, Stephen; Paula, José

    2009-06-01

    Estuarine and nearshore marine areas are vital habitats for several fish and benthic invertebrates. The shore crab Carcinus maenas (Crustacea: Brachyura: Portunidae) inhabits a variety of coastal, estuarine and lagoon habitats. At low tide, habitat structural complexity may be most important for crabs in the intertidal, providing refuge from predation and desiccation. The quality of different vegetated and nonvegetated estuarine and rocky shore habitats in SW Portugal and SW England was evaluated for intertidal C. maenas populations. We estimated population density, size-structure, and potential growth (RNA/DNA ratios) to investigate habitat quality. Vegetated estuarine habitats supported higher crab densities, than nonvegetated estuarine and rocky shore habitats. Investigation of population size-structure revealed that all habitats seem important recruitment and nursery areas although estuarine habitats in SW Portugal appeared to support higher densities of new recruits than equivalent habitats in SW England. Significant variation was found in RNA/DNA ratios among habitats. Ratios were highest in the rocky shore suggesting a high quality habitat where growth potential is high. We speculate that competition from other top-predators ( Pachygrapsus spp.) rather than low habitat quality may limit the occurrence of C. maenas in intertidal rocky shore habitats in SW Portugal. In estuarine environments RNA/DNA ratios were significantly higher in the vegetated than in the nonvegetated estuarine habitats in SW Portugal but not in SW England, suggesting geographic differences in the extent to which highly structure habitats represent high quality. Our results challenge the current paradigm that structured habitats are necessarily those of higher quality for C. maenas.

  5. Characterization of the Carcinus maenas Neuropeptidome by Mass Spectrometry and Functional Genomics

    PubMed Central

    Ma, Mingming; Bors, Eleanor K.; Dickinson, Evelyn S.; Kwiatkowski, Molly A.; Sousa, Gregory L.; Henry, Raymond P.; Smith, Christine M.; Towle, David W.; Christie, Andrew E.; Li, Lingjun

    2010-01-01

    Carcinus maenas, commonly known as the European green crab, is one of the best-known and most successful marine invasive species. While a variety of natural and anthropogenic mechanisms are responsible for the geographic spread of this crab, its ability to adapt physiologically to a broad range of salinities, temperatures and other environmental factors has enabled successful establishment in these new habitats. To extend our understanding of hormonal control in C. maenas, including factors that allow for its extreme adaptability, we have undertaken a mass spectral/functional genomics investigation of the neuropeptides used by this organism. Via a strategy combining MALDI-based high resolution mass profiling, biochemical derivatization, and nanoscale separation coupled to tandem mass spectrometric sequencing, 122 peptide paracrines/hormones were identified from the C. maenas central nervous system and neuroendocrine organs. These peptides include 31 previously described Carcinus neuropeptides (e.g. NSELINSILGLPKVMNDAamide [β-pigment dispersing hormone] and PFCNAFTGCamide [crustacean cardioactive peptide]), 49 peptides only described in species other than the green crab (e.g. pQTFQYSRGWTNamide [Arg7-corazonin]), and 42 new peptides de novo sequenced here for the first time (e.g. the pyrokinins TSFAFSPRLamide and DTGFAFSPRLamide). Of particular note are a collection of 25 FMRFamide-like peptides (including 9 new isoforms sequenced de novo) and a collection of 25 A-type allatostatin peptides (including 10 new sequences reported for the first time) in this study. Both peptide families are among the most diverse families, each containing a large number of isoforms in arthropod species. Also of interest was the identification of two SIFamide isoforms, GYRKPPFNGSIFamide and VYRKPPFNGSIFamide, the latter peptide known previously only from members of the astacidean genus Homarus. Using transcriptome analyses, 15 additional peptides were characterized, including an isoform

  6. The significance of nitrate in the nitrogenous excretion of carcinus maenas

    NASA Astrophysics Data System (ADS)

    Spaargaren, D. H.

    Total inorganic-N and NH 4+-N were measured in blood and external media of shore crabs, Carcinus maenas (L.), exposed to various salinities at low (4°C) and high (20°C) temperatures. Total inorganic-N and NH 4+-N were both excreted in larger amounts at lower salinities and at the higher temperature. Nitrate excretion is highest in brackish water and decreases in both higher and lower salinities. Nitrate excretion (0.11-0.72 μmol -1·h -1) was of the same order of magnitude as NH 4 + excretion, but in brackish water NO 3 - excretion predominated, whereas at lower salinities NH 4 + excretion predominated. NO 3 - formation may serve in the detoxification of NH 4 + and the maintenance of electroneutrality. Blood NO 3 - concentrations, like blood NH 4 + concentrations, are strongly stabilized, independent of either temperature or salinity.

  7. Modelling the biological invasion of Carcinus maenas (the European green crab).

    PubMed

    Marculis, Nathan G; Lui, Roger

    2016-01-01

    This paper proposes a system of integro-difference equations to model the spread of Carcinus maenas, commonly called the European green crab, that causes severe damage to coastal ecosystems. A model with juvenile and adult classes is first studied. Here, standard theory of monotone operators for integro-difference equations can be applied and yields explicit formulas for the asymptotic spreading speeds of the juvenile and adult crabs. A second model including an infected class is considered by introducing a castrating parasite Sacculina carcini as a biological control agent. The dynamics are complicated and simulations reveal the occurrence of periodic solutions and stacked fronts. In this case, only conjectures can be made for the asymptotic spreading speeds because of the lack of mathematical theory for non-monotone operators. This paper also emphasizes the need for mathematical studies of non-monotone operators in heterogeneous environments and the existence of stacked front solutions in biological invasion models. PMID:26673728

  8. Joint effects of salinity and the antidepressant sertraline on the estuarine decapod Carcinus maenas.

    PubMed

    Rodrigues, Aurélie P; Santos, Lúcia H M L M; Oliva-Teles, Maria Teresa; Delerue-Matos, Cristina; Guimarães, Laura

    2014-11-01

    Concurrent exposure of estuarine organisms to man-made and natural stressors has become a common occurrence. Numerous interactions of multiple stressors causing synergistic or antagonistic effects have been described. However, limited information is available on combined effects of emerging pharmaceuticals and natural stressors. This study investigated the joint effects of the antidepressant sertraline and salinity on Carcinus maenas. To improve knowledge about interactive effects and potential vulnerability, experiments were performed with organisms from two estuaries with differing histories of exposure to environmental contamination. Biomarkers related to mode of action of sertraline were employed to assess effects of environmentally realistic concentrations of sertraline at two salinity levels. Synergism and antagonism were identified for biomarkers of cholinergic neurotransmission, energy production, anti-oxidant defences and oxidative damage. Different interactions were found for the two study sites highlighting the need to account for differences in tolerance of local ecological receptors in risk evaluations. PMID:25217761

  9. Differences in the neighborhood: Structural variations in the carapace of shore crabs Carcinus maenas (Decapoda: Portunidae)

    NASA Astrophysics Data System (ADS)

    Souza, Allan T.; Ilarri, Martina I.; Campos, Joana; Marques, João C.; Martins, Irene

    2011-12-01

    The present study compared the carapace structure of Carcinus maenas in two nearby sites (2 km apart) within Minho estuary, submitted to different physicochemical and ecological conditions (water temperature, pH, crabs' density and sex ratio). The carapace structure of the carapace and chelae of the crabs presented significant differences between sampling sites ( t-test; p < 0.01). The SIMPER analysis revealed that the Weight/CW and Thickness/CW ratios explained all the dissimilarities found among sites. Overall, the male carapace was proportionally thicker at station 2 ( t-test; p < 0.01), while the female carapace was proportionally thicker at station 1 ( t-test; p < 0.001). A thicker carapace can be advantageous when competing for food or a sexual partner. We hypothetized that, since at station 2, the density of individuals was twice higher than at station 1, it is likely that agonistic encounters are more frequent, thus favouring a thicker carapace.

  10. 'Endogenous yolk' as the precursor of a possible fertilization envelope in a crab (Carcinus maenas).

    PubMed

    Goudeau, M; Lachaise, F

    1980-01-01

    After the egg attachment to a maternal ovigerous seta, the Carcinus maenas embryo is enclosed in a tripartite capsule. The innermost layer (envelope 2) which is also the main part of this capsule, is generally detected after egg-laying and is most probably closely related to the fecondation phenomenon. The precursor material of envelope 2, arising from the egg by a massive and very fast exocytosis process, appears as numerous ring-shaped granules. These granules, originated from numerous cortical vesicles perhaps intercommunicating with each others, are observed early in the ooplasm during oogenesis. These so-called ring-shaped granules seem very identical in form with the disc-shaped granules which are classically described as composing the endogenous or intracysternal yolk of many Decapoda crustacean oocytes. In view of our results the role of these granules, in endogenous yolk formation, is re-examined and discussed. PMID:7434334

  11. Die Schlei, ein Modell für die Verbreitung der Strandkrabbe Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Dries, M.; Adelung, D.

    1982-03-01

    A Carcinus maenas population inhabiting the Schlei, a glacial fjord of the Baltic Sea, was studied during a three-year period of at least monthly sampling. Due to slightly higher water temperatures in the Schlei (c. 1 °C higher than in the neighbouring waters of the western Baltic Sea) annual larval development starts there one month earlier. When in some years salinities are unfavourable (<13‰), larval development may be almost completely prevented. Juveniles and adults tolerate changing salinities, even though females prefer staying in deep waters and juveniles in shallow waters of high salinities. During winter all crabs move to deeper waters and stay huddled together in crevices and holes until March or April. Females usually moult after being fertilized, which takes place after the breeding season in August. Males moult between May and June; juveniles continue to moult during the warm season. Moulting for growth lasts until puberty is reached in the second year. From then on intermoult periods are more extended, but males moult more frequently than females, attaining ultimately a larger size. Under favourable environmental conditions, the maximum lifespan of C. maenas in the Schlei amounts to five years. During this period, five larval moults and about fifteen moults for growth occur.

  12. Sex identification of Carcinus maenas by analysis of carapace geometrical morphometry

    NASA Astrophysics Data System (ADS)

    Ledesma, Federico M.; Van der Molen, Silvina; Barón, Pedro J.

    2010-04-01

    The European green crab Carcinus maenas is a widely spread invasive species. Studying the most recently introduced population of the species in the Atlantic coast off Patagonia, it became apparent to us that carapaces (the dorsal cover of the visceral-cavity detaching from the rest of the exoskeleton after ecdysis) accumulated on the intertidal may be used as a valuable complementary material to analyze the size structure of crabs. However, since growth rate (and consequently size at instar) of crabs differs between males and females, finding a method to distinguish crab sex by observation of carapace morphology was necessary to allow the construction of independent size frequency distributions for each sex. In this work, we examined the shape of the carapaces from both sexes of C. maenas, and using Elliptical Fourier Analysis successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes.

  13. Carbonic anhydrase, a respiratory enzyme in the gills of the shore crab Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Böttcher, K.; Siebers, D.; Sender, S.

    1995-03-01

    This paper summarizes investigations on the enzyme carbonic anhydrase (CA) in the gills of the osmoregulating shore crab Carcinus maenas. Carbonic anhydrase, an enzyme catalyzing the reversible hydration of CO2 to HCO3 - and H+, is localized with highest activities in the posterior salt-transporting gills of the shore crab- and here CA activity is strongly dependent on salinity. Contrary to the earlier hypothesis established for the blue crab Callinectes sapidus that cytoplasmic branchial CA provides the counter ions HCO3 - and H+ for apical exchange against Na+ and Cl-, the involvement of CA in NaCl uptake mechanisms can be excluded in Carcinus. Differential and density gradient centrifugations indicate that branchial CA is a predominantly membrane-associated protein. Branchial CA was greatly inhibited by the sulfonamide acetazolamide (AZ) Ki=2.4·10-8 mol/l). Using the preparation of the isolated perfused gill, application of 10-4 mol/l AZ resulted in an 80% decrease of CO2/HCO3 - excretion. Thus we conclude that CA is localized in plasma membranes, maintaining the CO2 gradient by accelerating adjustment of the pH-dependent CO2/HCO3 - equilibrium.

  14. [Accumulation of Fe, Cu, Zn, Mg, Mn and Co in the ovary of Carcinus maenas L. during ovogenesis].

    PubMed

    Martin, J L; Ceccaldi, H J

    1976-01-01

    During ovogenesis the ovary of Carcinus maenas shows a continuous accumulation of Fe, Cu, Mg, Mn and Co. For Zn the accumulation seems to stop for gonad indexes near 6.5. The goal of this accumulation is not determined. Nevertheless we suppose that it is in relation with the role of organic reserves that possess the female sexual cells in decapods and with the synthesis of enzymes and hemocyanin. PMID:134766

  15. Positive feedback fishery: Population consequences of `crab-tiling' on the green crab Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Sheehan, E. V.; Thompson, R. C.; Coleman, R. A.; Attrill, M. J.

    2008-11-01

    Collection of marine invertebrates for use as fishing bait is a substantial activity in many parts of the world, often with unknown ecological consequences. As new fisheries develop, it is critical for environmental managers to have high quality ecological information regarding the potential impacts, in order to develop sound management strategies. Crab-tiling is a largely unregulated and un-researched fishery, which operates commercially in the south-west UK. The target species is the green crab Carcinus maenas. Those crabs which are pre-ecdysis and have a carapace width greater than 40 mm are collected to be sold to recreational anglers as bait. Collection involves laying artificial structures on intertidal sandflats and mudflats in estuaries. Crabs use these structures as refugia and are collected during low tide. However, the effect that this fishery has on populations of C. maenas is not known. The impact of crab-tiling on C. maenas population structure was determined by sampling crabs from tiled estuaries and non-tiled estuaries using baited drop-nets. A spatially and temporarily replicated, balanced design was used to compare crab abundance, sizes and sex ratios between estuaries. Typically, fisheries are associated with a reduction in the abundance of the target species. Crab-tiling, however, significantly increased C. maenas abundance. This was thought to be a result of the extra habitat in tiled estuaries, which probably provides protection from natural predators, such as birds and fish. Although crabs were more abundant in tiled estuaries than non-tiled estuaries, the overall percentage of reproductively active crabs in non-tiled estuaries was greater than in tiled estuaries. As with most exploited fisheries stocks, crabs in exploited (tiled) estuaries tended to be smaller, with a modal carapace width of 20-29 mm rather than 30-39 mm in non-tiled estuaries. The sex ratio of crabs however; was not significantly different between tiled and non

  16. Osmotic and ionic regulation in shore crabs Carcinus maenas inhabiting a tidal estuary

    NASA Astrophysics Data System (ADS)

    Winkler, A.; Siebers, D.; Becker, W.

    1988-03-01

    Shore crabs Carcinus maenas were exposed to salinities fluctuating according to the natural tidal rhythm. To this end they were maintained in net cages positioned in the estuarine waters of the river Elbe. The cages were lifted every hour, and between 8 12 specimens were analyzed for hemolymph concentrations of Na, K, Ca, Mg, and osmolality. The results obtained were compared with the respective data measured in external brackish water. In addition, the specific activity of Na-K-ATPase in a posterior gill was determined. Hemolymph Na and Mg as well as branchial Na-K-ATPase were also determined in crabs collected in the North Sea and the Baltic. The results show that in C. maenas living in salinities fluctuating with the tides by approx. 15‰ S, Na, K and Ca were hyperregulated, and Mg was effectively hyporegulated. The concentrations of all hemolymph ions and the activity of the Na-K-ATPase were kept constant over the whole tidal cycle. In Baltic crabs, Na was effectively hyperregulated and gill Na-K-ATPase was significantly elevated by a factor of ca 2 when compared with North Sea crabs. It is suggested that long-term hyperregulation of Na in constant salinities results from an increased number of Na-K-ATPase molecules which may change by synthesis or degradation following salinity stress. Constant hemolymph levels of hyperregulated Na in crabs inhabiting fluctuating brackish water are accomplished by activation of existing Na-K-ATPase by low Na and inhibition by higher ambient concentrations.

  17. The ability to feed in hypoxia follows a seasonally dependent pattern in shore crab Carcinus maenas.

    PubMed

    Legeay; Massabuau

    2000-04-26

    The ability of the adult shore crab Carcinus maenas, native to the Bay of Arcachon (SW France), to feed in hypoxia was determined at various seasons. Crabs previously kept at field temperature were fed after a 5-day fasting period at 15 degrees C. Their blood oxygenation and pH regulation strategy and also their gill anatomy were analysed. From May to October, C. maenas feed at levels of O(2) partial pressure (p(O(2))) in the water, pwO(2)=2 kPa (1 mg l(-1)), without switching to their anaerobic metabolism. In March-April, before the main moulting period, the same food intake at pwO(2)=4 kPa induced a systematic blood lactate increase associated with some mortality. An analysis performed at pwO(2)=4 kPa at that time showed that in intermoult crabs the development of a coating of foreign material over the gill cuticle interfered with O(2)-supply, preventing the small arterial p(O(2)) increases (from 0.7 to 1 kPa) which occurred at other seasons. This led to a cellular hypoxia despite a systematic postprandial blood-pH alkalinisation which favoured O(2)-loading at gill level and increased arterial O(2) concentration. In March-April, alkalinisation appeared at pwO(2) values >/=6 kPa and from May to at least July at pwO(2)>/=2 kPa. Results are discussed in terms of season-related physiological performance, as hypoxic events mainly occur during the hot season. PMID:10727691

  18. Contaminant effects in shore crabs (Carcinus maenas) from Ria Formosa Lagoon.

    PubMed

    Maria, V L; Santos, M A; Bebianno, M J

    2009-08-01

    Defence and damage biomarkers signals were studied in female and male shore crabs Carcinus maenas transplanted between two sites at Ria Formosa Lagoon (South of Portugal). The cross transplantation occurred during 6 days at a hypothetical reference site (Ramalhete), and a contaminated site (Olhão). DNA unwinding technique was used for DNA integrity measurement. General enzymatic antioxidant responses in gills and hepatopancreas (catalase and gills glutathione peroxidase activities increase) showed that cross transplanted crabs (female and male) are suffering from pro-oxidant challenges at the Olhão site. Gills and hepatopancreas glutathione-S-transferase were reduced in both gender crabs transplanted from Ramalhete to Olhão. Metallothioneins induction occurred in crabs transplanted from Ramalhete to Olhão (contaminated by metals and polycyclic aromatic hydrocarbons (PAHs)). However metallothionein differences were also observed towards gender and organ specificities. High gills lipid peroxidation exist in male crabs transplanted from Ramalhete to Olhão, while in females it was the opposite. In both gender crabs from the Olhão site, gills DNA integrity decreased compared to the Ramalhete feral crabs. Moreover, hepatopancreas DNA integrity decreased in male crabs transplanted from Olhão to Ramalhete site which may be related to the environmental conditions (lower contamination levels) revealing the difficulty of selection of reference sites in field studies. Data demonstrated that female and male C. maenas antioxidant defences and damage biomarkers were sensitive to the mixture of contaminants present in these sites as well as good indicators of general stress.

  19. Exposure of Carcinus maenas to waterborne fluoranthene: accumulation and multibiomarker responses.

    PubMed

    Rodrigues, A P; Lehtonen, K K; Guilhermino, L; Guimarães, L

    2013-01-15

    Fluoranthene (FLU) is a priority polycyclic aromatic hydrocarbon (PAH) commonly detected in estuarine sediments, water and biota. Despite this, information on FLU detection, accumulation and effects on marine crustaceans is scarce. This work investigated the accumulation of FLU in Carcinus maenas and the responses of several early-warning biomarkers after a 7-day laboratory exposure to five FLU concentrations (2.56 to 100 μg L(-1)). After exposure to FLU, sub-samples of the crabs' digestive gland and muscle were collected for biomarker determinations. The remaining digestive gland and muscle, together with the rest of the whole-body soft tissues, were analysed for FLU residues by gas chromatography-mass spectrometry (GC-MS). The biomarkers assessed were: i) the quantification of FLU-type compounds by fixed wavelength fluorescence (FF); ii) the activities of glutathione S-transferases (GST) and glutathione reductase (GR), and the levels of total glutathione (GT) and lipid peroxidation (LPO) for oxidative stress; iii) the activity of acetylcholinesterase (AChE) for neurotoxicity; iv) the activities of isocitrate dehydrogenase (IDH) and lactate dehydrogenase (LDH) enzymes, and total protein, glycogen and lipids as indicators of changes in energy metabolism and storage; and v) the lysosomal membrane stability (LMS) as a measure of cell damage. The results showed strong (R(2)>0.95) concentration-dependent accumulation of FLU residues (as measured by GC-MS) in the remaining whole-body soft tissues and of FLU-type compounds (as measured by FF) in the digestive gland and muscle. A strong positive linear relationship (R(2)=0.91) between FLU residues and FLU-type compounds was also found. Comparing to controls, activities of GST and GR were significantly higher in crabs exposed to ≥16 and ≥40 μg L(-1) FLU, respectively. TG levels and IDH activity showed a significant trend to increase with FLU concentrations whereas AChE activity exhibited the opposite trend. FF

  20. Fecampia erythrocephala rediscovered: Prevalence and distribution of a parasitoid of the European shore crab, Carcinus maenas

    USGS Publications Warehouse

    Kuris, A.M.; Torchin, M.E.; Lafferty, K.D.

    2002-01-01

    An ecological assessment of Fecampia erythrocephala, reporting its habitat distribution, abundance, host specificity, size-specific prevalence, frequency distribution among hosts, effect on host growth, and its site specificity within these hosts is presented. At the Isle of Man and near Plymouth, Fecampia erythrocephala cocoons were generally abundant on the undersides of rocks in the Ascophyllum and Fucus serratus zones. Infected crabs were also most common in these habitats. Both Carcinus maenas and Cancer pagurus were parasitized at similar prevalences, although the former species was relatively much more common in the habitats where the worm cocoons were abundant. Fecampia erythrocephala did not infect crabs larger than 11 mm carapace width, and prevalence decreased significantly with crab size. Prevalences reached 11% in areas where cocoons were abundant. Together with the large size of these worms relative to the size of the host crabs and the observations on worm emergence, these life history features indicate that F. erythrocephala is a parasitoid of young shore crabs. Fecampia erythrocephala cocoon abundance is often high in localized areas and size-prevalence information suggests that worms mature rapidly in these crabs. This suggests that F. erythrocephala is an important contributor to crab mortality and to the ecology of shore crabs at these sites.

  1. Effect of Microplastic on the Gills of the Shore Crab Carcinus maenas.

    PubMed

    Watts, Andrew J R; Urbina, Mauricio A; Goodhead, Rhys; Moger, Julian; Lewis, Ceri; Galloway, Tamara S

    2016-05-17

    Microscopic plastic debris (microplastics, <5 mm in diameter) is ubiquitous in the marine environment. Previous work has shown that microplastics may be ingested and inhaled by the shore crab Carcinus maenas, although the biological consequences are unknown. Here, we show that acute aqueous exposure to polystyrene microspheres (8 μm) with different surface coatings had significant but transient effects on branchial function. Microspheres inhaled into the gill chamber had a small but significant dose-dependent effect on oxygen consumption after 1 h of exposure, returning to normal levels after 16 h. Ion exchange was also affected, with a small but significant decrease in hemolymph sodium ions and an increase in calcium ions after 24 h post-exposure. To further asses the effects on osmoregulation, we challenged crabs with reduced salinity after microplastic exposure. Neither microspheres nor natural sediments altered the crab's response to osmotic stress regardless of plastic concentration added. Carboxylated (COOH) and aminated (NH2) polystyrene microspheres were distributed differently across the gill surface, although neither had a significant adverse impact on gill function. These results illustrate the extent of the physiological effects of microplastics compared to the physiological resilience of shore crabs in maintaining osmoregulatory and respiratory function after acute exposure to both anthropogenic plastics and natural particles.

  2. Camouflage and individual variation in shore crabs (Carcinus maenas) from different habitats.

    PubMed

    Stevens, Martin; Lown, Alice E; Wood, Louisa E

    2014-01-01

    Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, little work has objectively quantified the appearances of camouflaged animals from different habitats, or related this to factors such as ontogeny and individual variation. Here, we tested for phenotype-environment associations in the common shore crab (Carcinus maenas), a species highly variable in appearance and found in a wide range of habitats. We used field surveys and digital image analysis of the colors and patterns of crabs found in four locations around Cornwall in the UK to quantify how individuals vary with habitat (predominantly rockpool, mussel bed, and mudflat). We find that individuals from sites comprising different backgrounds show substantial differences in several aspects of color and pattern, and that this is also dependent on life stage (adult or juvenile). Furthermore, the level of individual variation is dependent on site and life stage, with juvenile crabs often more variable than adults, and individuals from more homogenous habitats less diverse. Ours is the most comprehensive study to date exploring phenotype-environment associations for camouflage and individual variation in a species, and we discuss the implications of our results in terms of the mechanisms and selection pressures that may drive this. PMID:25551233

  3. Mitochondrial ATPase in the gills of the shore crab Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Siebers, D.; Hentschel, J.; Böttcher, K.; Lucu, C.

    1992-12-01

    Posterior gills (No. 7 and 8) of shore crabs Carcinus maenas were homogenized and fractionated by means of differential and density gradient centrifugation. Employment of marker enzymes Na-K-ATPase and carbonic anhydrase for plasma membranes and cytochrome oxidase for mitochondria showed that these structural elements were separated. Ultramicroscopic investigations of combined fractions confirmed the presence of the respective mitochondrial and vesicular plasma membrane structures. An ATPase which did not depend on the presence of sodium (20 mM) ions in the incubation medium but on the presence of potassium (20 mM) ions only was found in the mitochondrial fractions. The mitochondrial ATPase was tightly bound to cellular particulates and activated approximately threefold by bicarbonate (20 mM) ions. The activity of this ATPase was nearly completely inhibited by oligomycin (1 μg ml-1) and greatly inhibited by low levels (5 mM) of thiocyanate and calcium ions, the Ki for Ca2+ being ca 4 mM. The results obtained confirm literature data on high mitochondrial densities in crab gills and allow the assumption of significant rates of energy metabolism in these organs. Considering its properties the mitochondrial ATPase is clearly distinct from crab gill Na-K-ATPase and can be measured specifically in samples containing Na-K-ATPase. Mitochondrial ATPase is therefore considered a suitable and reliable marker enzyme for mitochondria.

  4. Uptake and retention of microplastics by the shore crab Carcinus maenas.

    PubMed

    Watts, Andrew J R; Lewis, Ceri; Goodhead, Rhys M; Beckett, Stephen J; Moger, Julian; Tyler, Charles R; Galloway, Tamara S

    2014-01-01

    Microplastics, plastics particles <5 mm in length, are a widespread pollutant of the marine environment. Oral ingestion of microplastics has been reported for a wide range of marine biota, but uptake into the body by other routes has received less attention. Here, we test the hypothesis that the shore crab (Carcinus maenas) can take up microplastics through inspiration across the gills as well as ingestion of pre-exposed food (common mussel Mytilus edulis). We used fluorescently labeled polystyrene microspheres (8-10 μm) to show that ingested microspheres were retained within the body tissues of the crabs for up to 14 days following ingestion and up to 21 days following inspiration across the gill, with uptake significantly higher into the posterior versus anterior gills. Multiphoton imaging suggested that most microspheres were retained in the foregut after dietary exposure due to adherence to the hairlike setae and were found on the external surface of gills following aqueous exposure. Results were used to construct a simple conceptual model of particle flow for the gills and the gut. These results identify ventilation as a route of uptake of microplastics into a common marine nonfilter feeding species. PMID:24972075

  5. Identification of biomarkers responsive to chronic exposure to pharmaceuticals in target tissues of Carcinus maenas.

    PubMed

    Aguirre-Martínez, G V; Del Valls, T A; Martín-Díaz, M L

    2013-01-01

    A 28-day bioassay was performed with Carcinus maenas to evaluate chronic effects caused by exposure to caffeine and ibuprofen (0.1-50 μg L(-1)) in sea water. Lysosomal membrane stability (LMS) was evaluated in hemolymph applying the neutral red retention assay (NRRA); several biomarkers including ethoxyresorufin O-deethylase (EROD), dibenzylfluorescein dealkylase (DBF), glutathione S-transferase (GST), glutathione peroxidase (GPX), lipid peroxidation (LPO) and DNA damage were studied in gill, hepatopancreas, muscle and gonad tissues. In crabs exposed to environmental concentrations of the drugs, retention time was reduced by 50%. EROD and DBFOD activities were induced by caffeine in muscle and hepatopancreas tissues (p < 0.05); GST activity was activated by ibuprofen in gill, hepatopancreas and muscle at the highest concentrations tested (p < 0.05). All tissues showed GPX activity and LPO induction (p < 0.05). Crabs exposed to caffeine and ibuprofen showed evidence of DNA damage mainly in hepatopancreas tissues (p < 0.05). Environmental concentrations of pharmaceuticals induce LMS and the biochemical responses studied in this crab. This methodology is a suitable technique for assessing pharmaceutical toxicity in the marine environment. PMID:23562135

  6. Metals bioaccumulation and histopathological biomarkers in Carcinus maenas crab from Bizerta lagoon, Tunisia.

    PubMed

    Ben-Khedher, Sana; Jebali, Jamel; Houas, Zohra; Nawéli, Hmida; Jrad, Amel; Banni, Mohamed; Boussetta, Hamadi

    2014-03-01

    Metals concentrations and histolopathological lesions of gills and digestive gland were investigated in Carcinus maenas crabs sampled from Bizerta Lagoon and Kuriat Island (Tunisia) as control site. The concentrations of trace metals varied between tissues, sites and sampling time. The highest levels of the analysed metals in gills and digestive gland were noted in Menzel Bourguiba and Cimentery sites at both sampling times (February and July). The higher metals loads were associated with severe and various tissues alterations in contaminated crabs. We particularly noted in the gills a haemocytic infiltration, distension and enlargement of the lamellae, lifting of lamellar epithelium, necrotic lesions and fusion of lamellae in the most polluted sites (Menzel Bourguiba and Cimentery). Moreover, others pathological alterations were observed in digestive gland of crabs collected from polluted sites and with a severity site dependent. We observed necrotic tubules containing tissue debris in the lumen with more intensity in crabs collected from Cimentery site in both sampling times. The thickened basal laminae and the walling off of the tubules by haemocytes around the thickened basal laminae were more abundant at Menzel Bourguiba than at others sites. The coagulation in the thickened basal laminae was observed only at Cimentery in February. Tissues histopathological lesions were sensitive to discriminate crabs of different sites and demonstrated its usefulness in this biomonitoring study. We recommend the association of histopatholocial lesions to biochemical biomarkers in future biomonitoring studies. PMID:24323326

  7. Effect of nanomaterials on the compound action potential of the shore crab, Carcinus maenas.

    PubMed

    Windeatt, Kirsten M; Handy, Richard D

    2013-06-01

    Little is known about the effects of manufactured nanomaterials on the function of nerves. The experiment aimed to test the effects of three different nanomaterials (1 mg l⁻¹ of TiO₂ NPs, Ag NPs or SWCNT) on the compound action potential of the shore crab (Carcinus maenas) compared with an appropriate bulk powder or metal salt control (bulk TiO₂ powder, AgNO₃ and carbon black respectively). In single action potential recordings, there were no effects of any of the nanomaterials on the peak amplitude, duration, rate of rise (depolarisation), or rate of decrease (repolarisation) of the compound action potential in crab saline, despite settling of each nanomaterial directly onto the nerve preparation. The ability of the crab nerve to be stimulated to tetanus was also unaffected by exposure to the nanomaterials compared with the appropriate bulk powder or metal salt control. Solvent controls with sodium dodecyl sulfate (SDS) also had no effect on action potentials. Overall, the study concludes that there were no effects of the materials at the concentrations tested on the compound action potential of the shore crab in physiological saline. PMID:22394242

  8. Using environmental proteomics to assess pollutant response of Carcinus maenas along the Tunisian coast.

    PubMed

    Ghedira, Jihene; Chicano-Gálvez, Eduardo; Fernández-Cisnal, Ricardo; Jebali, Jamel; Banni, Mohamed; Chouba, Lassaad; Boussetta, Hamadi; López-Barea, Juan; Alhama, José

    2016-01-15

    Biochemical responses to pollutants were studied at four Tunisia littoral sites using Carcinus maenas as a bioindicator. Proteomic analysis was used to assess the global impact of complex pollution mixtures, and to provide new biomarkers and basic insights into pollutant toxicity. Metal contents and metallothionein levels followed a gradient based on sampling sites: Bizerte ≫ Teboulba > Gargour~Mahres. Approximately 900 and 700 spots were resolved in digestive glands and gills, respectively. Gills from Bizerte animals had the maximum number of altered spots, mostly upregulated. In other locations, the number of altered spots in gills decreased in parallel to total metals in in the following order: Teboulba > Gargour > Mahres (mostly downregulated). Out of the 39 spots excised, ten proteins were identified in digestive glands and eight in gills. Digestive glands of Bizerte crabs had higher levels of ferritin, three vitellogenin forms and mannose-binding protein, while Gargour crabs had higher levels of four cryptocyanin forms. Gills of Bizerte crabs had higher levels of ferritin, three vitellogenins forms, lectin 4C, actin, and collagenolytic serine protease. Proteins with altered expression in crabs from Tunisia littoral are related to molting, oxidative stress and inflammation, innate immune response, and proteolysis. PMID:26402481

  9. Trophic level transfer of microplastic: Mytilus edulis (L.) to Carcinus maenas (L.).

    PubMed

    Farrell, Paul; Nelson, Kathryn

    2013-06-01

    This study investigated the trophic transfer of microplastic from mussels to crabs. Mussels (Mytilus edulis) were exposed to 0.5 μm fluorescent polystyrene microspheres, then fed to crabs (Carcinus maenas). Tissue samples were then taken at intervals up to 21 days. The number of microspheres in the haemolymph of the crabs was highest at 24 h (15 033 ml(-1) ± SE 3146), and was almost gone after 21 days (267 ml(-1) ± SE 120). The maximum amount of microspheres in the haemolymph was 0.04% of the amount to which the mussels were exposed. Microspheres were also found in the stomach, hepatopancreas, ovary and gills of the crabs, in decreasing numbers over the trial period. This study is the first to show 'natural' trophic transfer of microplastic, and its translocation to haemolymph and tissues of a crab. This has implications for the health of marine organisms, the wider food web and humans. PMID:23434827

  10. Uptake and retention of microplastics by the shore crab Carcinus maenas.

    PubMed

    Watts, Andrew J R; Lewis, Ceri; Goodhead, Rhys M; Beckett, Stephen J; Moger, Julian; Tyler, Charles R; Galloway, Tamara S

    2014-01-01

    Microplastics, plastics particles <5 mm in length, are a widespread pollutant of the marine environment. Oral ingestion of microplastics has been reported for a wide range of marine biota, but uptake into the body by other routes has received less attention. Here, we test the hypothesis that the shore crab (Carcinus maenas) can take up microplastics through inspiration across the gills as well as ingestion of pre-exposed food (common mussel Mytilus edulis). We used fluorescently labeled polystyrene microspheres (8-10 μm) to show that ingested microspheres were retained within the body tissues of the crabs for up to 14 days following ingestion and up to 21 days following inspiration across the gill, with uptake significantly higher into the posterior versus anterior gills. Multiphoton imaging suggested that most microspheres were retained in the foregut after dietary exposure due to adherence to the hairlike setae and were found on the external surface of gills following aqueous exposure. Results were used to construct a simple conceptual model of particle flow for the gills and the gut. These results identify ventilation as a route of uptake of microplastics into a common marine nonfilter feeding species.

  11. Trophic level transfer of microplastic: Mytilus edulis (L.) to Carcinus maenas (L.).

    PubMed

    Farrell, Paul; Nelson, Kathryn

    2013-06-01

    This study investigated the trophic transfer of microplastic from mussels to crabs. Mussels (Mytilus edulis) were exposed to 0.5 μm fluorescent polystyrene microspheres, then fed to crabs (Carcinus maenas). Tissue samples were then taken at intervals up to 21 days. The number of microspheres in the haemolymph of the crabs was highest at 24 h (15 033 ml(-1) ± SE 3146), and was almost gone after 21 days (267 ml(-1) ± SE 120). The maximum amount of microspheres in the haemolymph was 0.04% of the amount to which the mussels were exposed. Microspheres were also found in the stomach, hepatopancreas, ovary and gills of the crabs, in decreasing numbers over the trial period. This study is the first to show 'natural' trophic transfer of microplastic, and its translocation to haemolymph and tissues of a crab. This has implications for the health of marine organisms, the wider food web and humans.

  12. Effect of Microplastic on the Gills of the Shore Crab Carcinus maenas.

    PubMed

    Watts, Andrew J R; Urbina, Mauricio A; Goodhead, Rhys; Moger, Julian; Lewis, Ceri; Galloway, Tamara S

    2016-05-17

    Microscopic plastic debris (microplastics, <5 mm in diameter) is ubiquitous in the marine environment. Previous work has shown that microplastics may be ingested and inhaled by the shore crab Carcinus maenas, although the biological consequences are unknown. Here, we show that acute aqueous exposure to polystyrene microspheres (8 μm) with different surface coatings had significant but transient effects on branchial function. Microspheres inhaled into the gill chamber had a small but significant dose-dependent effect on oxygen consumption after 1 h of exposure, returning to normal levels after 16 h. Ion exchange was also affected, with a small but significant decrease in hemolymph sodium ions and an increase in calcium ions after 24 h post-exposure. To further asses the effects on osmoregulation, we challenged crabs with reduced salinity after microplastic exposure. Neither microspheres nor natural sediments altered the crab's response to osmotic stress regardless of plastic concentration added. Carboxylated (COOH) and aminated (NH2) polystyrene microspheres were distributed differently across the gill surface, although neither had a significant adverse impact on gill function. These results illustrate the extent of the physiological effects of microplastics compared to the physiological resilience of shore crabs in maintaining osmoregulatory and respiratory function after acute exposure to both anthropogenic plastics and natural particles. PMID:27070459

  13. Camouflage and individual variation in shore crabs (Carcinus maenas) from different habitats.

    PubMed

    Stevens, Martin; Lown, Alice E; Wood, Louisa E

    2014-01-01

    Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, little work has objectively quantified the appearances of camouflaged animals from different habitats, or related this to factors such as ontogeny and individual variation. Here, we tested for phenotype-environment associations in the common shore crab (Carcinus maenas), a species highly variable in appearance and found in a wide range of habitats. We used field surveys and digital image analysis of the colors and patterns of crabs found in four locations around Cornwall in the UK to quantify how individuals vary with habitat (predominantly rockpool, mussel bed, and mudflat). We find that individuals from sites comprising different backgrounds show substantial differences in several aspects of color and pattern, and that this is also dependent on life stage (adult or juvenile). Furthermore, the level of individual variation is dependent on site and life stage, with juvenile crabs often more variable than adults, and individuals from more homogenous habitats less diverse. Ours is the most comprehensive study to date exploring phenotype-environment associations for camouflage and individual variation in a species, and we discuss the implications of our results in terms of the mechanisms and selection pressures that may drive this.

  14. Camouflage and Individual Variation in Shore Crabs (Carcinus maenas) from Different Habitats

    PubMed Central

    Stevens, Martin; Lown, Alice E.; Wood, Louisa E.

    2014-01-01

    Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, little work has objectively quantified the appearances of camouflaged animals from different habitats, or related this to factors such as ontogeny and individual variation. Here, we tested for phenotype-environment associations in the common shore crab (Carcinus maenas), a species highly variable in appearance and found in a wide range of habitats. We used field surveys and digital image analysis of the colors and patterns of crabs found in four locations around Cornwall in the UK to quantify how individuals vary with habitat (predominantly rockpool, mussel bed, and mudflat). We find that individuals from sites comprising different backgrounds show substantial differences in several aspects of color and pattern, and that this is also dependent on life stage (adult or juvenile). Furthermore, the level of individual variation is dependent on site and life stage, with juvenile crabs often more variable than adults, and individuals from more homogenous habitats less diverse. Ours is the most comprehensive study to date exploring phenotype-environment associations for camouflage and individual variation in a species, and we discuss the implications of our results in terms of the mechanisms and selection pressures that may drive this. PMID:25551233

  15. Proteomic analysis in caged Mediterranean crab (Carcinus maenas) and chemical contaminant exposure in Téboulba Harbour, Tunisia.

    PubMed

    Jebali, Jamel; Chicano-Gálvez, Eduardo; Fernández-Cisnal, Ricardo; Banni, Mohamed; Chouba, Lassaad; Boussetta, Hamadi; López-Barea, Juan; Alhama, José

    2014-02-01

    This study uses proteomics approach to assess the toxic effects of contaminants in the Mediterranean crab (Carcinus maenas) after transplantation into Téboulba fishing harbour. High levels of aliphatic and aromatic hydrocarbons were detected in sediments. Although their effects on vertebrates are well described, little is known about their early biological effects in marine invertebrates under realistic conditions. Protein expression profiles of crabs caged for 15, 30 and 60 days were compared to unexposed animals. Nineteen proteins with significant expression differences were identified by capLC-µESI-IT MS/MS and homology search on databases. Differentially expressed proteins were assigned to five different categories of biological function including: (1) chitin catabolism, (2) proteolysis, (3) exoskeleton biosynthesis, (4) protein folding and stress response, and (5) transport. The proteins showing major expression changes in C. maenas after different caging times may be considered as novel molecular biomarkers for effectively biomonitoring aquatic environment contamination. PMID:24433786

  16. N-Acetyl-β-D-glucosaminidase activity in feral Carcinus maenas exposed to cadmium.

    PubMed

    Mesquita, Sofia Raquel; Ergen, Şeyda Fikirdeşici; Rodrigues, Aurélie Pinto; Oliva-Teles, M Teresa; Delerue-Matos, Cristina; Guimarães, Laura

    2015-02-01

    Cadmium is a priority hazardous substance, persistent in the aquatic environment, with the capacity to interfere with crustacean moulting. Moulting is a vital process dictating crustacean growth, reproduction and metamorphosis. However, for many organisms, moult disruption is difficult to evaluate in the short term, what limits its inclusion in monitoring programmes. N-acetyl-β-D-glucosaminidase (NAGase) is an enzyme acting in the final steps of the endocrine-regulated moulting cascade, allowing for the cast off of the old exoskeleton, with potential interest as a biomarker of moult disruption. This study investigated responses to waterborne cadmium of NAGase activity of Carcinus maenas originating from estuaries with different histories of anthropogenic contamination: a low impacted and a moderately polluted one. Crabs from both sites were individually exposed for seven days to cadmium concentrations ranging from 1.3 to 2000 μg/L. At the end of the assays, NAGase activity was assessed in the epidermis and digestive gland. Detoxification, antioxidant, energy production, and oxidative stress biomarkers implicated in cadmium metabolism and tolerance were also assessed to better understand differential NAGase responses: activity of glutathione S-transferases (GST), glutathione peroxidase (GPx) glutathione reductase (GR), levels of total glutathiones (TG), lipid peroxidation (LPO), lactate dehydrogenase (LDH), and NADP(+)-dependent isocitrate dehydrogenase (IDH). Animals from the moderately polluted estuary had lower NAGase activity both in the epidermis and digestive gland than in the low impacted site. NAGase activity in the epidermis and digestive gland of C. maenas from both estuaries was sensitive to cadmium exposure suggesting its usefulness for inclusion in monitoring programmes. However, in the digestive gland NAGase inhibition was found in crabs from the less impacted site but not in those from the moderately contaminated one. Altered glutathione levels were

  17. Bursicon and neuropeptide cascades during the ecdysis program of the shore crab, Carcinus maenas.

    PubMed

    Webster, Simon George; Wilcockson, David Charles; Mrinalini; Sharp, Jasmine Heloise

    2013-02-01

    Very little is known regarding the release patterns of neuropeptides involved in ecdysis of crustaceans compared to insects. In particular, the dynamics of release of the insect cuticle hardening hormone bursicon, which has only recently been discovered in crustaceans, is unknown. Bursicon has not previously been identified as a circulating neurohormone in these animals. Since patterns of release were likely to be ephemeral, bursicon, as well as two other neurohormones involved in the ecdysis program in crustaceans, crustacean cardioactive peptide (CCAP) and crustacean hyperglycaemic hormone (CHH) were measured in single haemolymph samples in Carcinus maenas. For bursicon, an ultrasensitive time resolved-fluoroimmunoassay (TR-FIA) was developed, which firstly involved its characterisation by HPLC, bioassay and immunoassay. Simultaneous measurement of three neurohormones was performed at unparalleled levels of resolution, which has not previously been reported in any invertebrate. Additionally, expression patterns and architecture of neurones expressing both bursicon and CCAP were determined in the CNS during the moult cycle. Bursicon and CCAP are released in a massive surge, likely a single global exocytotic event on emergence, just after release of CHH. Despite co-localisation of CCAP and bursicon in neurones of the CNS, observations suggest that differential packaging of CCAP can occur in the pericardial organs in a small population of secretory boutons, thus accounting for observations showing release of some CCAP during the penultimate stages of the ecdysis program. The results obtained vividly illustrate the dynamism of neuropeptide cascades occurring during crustacean ecdysis, and also allow proposal of a hypothesis of its endocrine control. PMID:23247273

  18. Nitric oxide production and sequestration in the sinus gland of the green shore crab Carcinus maenas.

    PubMed

    Pitts, Natalie L; Mykles, Donald L

    2015-02-01

    Molting in decapod crustaceans is regulated by molt-inhibiting hormone (MIH), a neuropeptide produced in the X-organ (XO)/sinus gland (SG) complex of the eyestalk ganglia (ESG). Pulsatile release of MIH from the SG suppresses ecdysteroidogenesis by the molting gland or Y-organ (YO). The hypothesis is that nitric oxide (NO), a neuromodulator that controls neurotransmitter release at presynaptic membranes, depresses the frequency and/or amount of MIH pulses to induce molting. NO synthase (NOS) mRNA was present in Carcinus maenas ESG and other tissues and NOS protein was present in the SG. A copper based ligand (CuFL), which reacts with NO to form a highly fluorescent product (NO-FL), was used to image NO in the ESG and SG and quantify the effects of NO scavenger (cPTIO), NOS inhibitor (l-NAME), and sodium azide (NaN3) on NO production in the SG. Pre-incubation with cPTIO prior to CuFL loading decreased NO-FL fluorescence ~30%; including l-NAME had no additional effect. Incubating SG with l-NAME during pre-incubation and loading decreased NO-FL fluorescence ~40%, indicating that over half of the NO release was not directly dependent on NOS activity. Azide, which reacts with NO-binding metal groups in proteins, reduced NO-FL fluorescence to near background levels without extensive cell death. Spectral shift analysis showed that azide displaced NO from a soluble protein in SG extract. These data suggest that the SG contains NO-binding protein(s) that sequester NO and releases it over a prolonged period. This NO release may modulate neuropeptide secretion from the axon termini in the SG. PMID:25452501

  19. The ammonium excretion of the shore crab, carcinus maenas, in relation to environmental osmotic conditions

    NASA Astrophysics Data System (ADS)

    Spaargaren, D. H.

    Ammonia concentrations were measured in blood and external media of shore crabs, Carcinus maenas, acclimated to 6 different salinities at high (20° C) and low (4° C) temperatures. It is seen that environmental osmotic conditions (temperature and salinity) have a major influence on NH 4+ formation and thus on protein (amino acid) catabolism. Blood ammonia concentrations appear to be strongly stabilized, independent of environmental osmotic conditions, ranging between 0.25 and 0.55 mmol·l -1. At normal, low environmental NH 4+ concentrations blood NH 4+ is strongly hyper-ionic compared to external concentrations; at high environmental NH 4+ concentrations (even when artificially raised to 2.5 mmol·l -1), blood NH 4+ is strongly hypo-ionic. Regulation of the blood NH 4+ concentrations takes place by a variable efflux of NH 4+; at high environmental NH 4+ concentrations (> 0.28 mmol · l -1), in addition to a high NH 4+ efflux, stabilization of the blood NH 4+ concentrations is effectuated by the formation of urea. Ammonia efflux to the surrounding water is highly dependent to the osmotic conditions of the environment: viz. positively related to temperature and inversely related to external salinity, with relatively stable value near the isosmotic salinity. Related to the strong variations in ammonia efflux, external NH 4+ concentrations in a closed volume of water are highly variable. In the course of time very high values develop in media of low salinity at high temperature. A close connection between NH 4+ excretion and extracellular ion regulation is indicated.

  20. Active uptake of sodium in the gills of the hyperregulating shore crab Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Siebers, D.; Lucu, Č.; Winkler, A.; Dalla Venezia, L.; Wille, H.

    1986-03-01

    Isolated posterior gills of shore crabs, Carcinus maenas, previously acclimated for at least 1 month to brackish water of 10 ‰ S, were connected with an artificial hemolymph circulation by means of thin polyethylene tubings. Gills were symmetrically perfused and bathed with 50 % sea water. Transepithelial potential differences (PDs) and fluxes of sodium between medium and blood were measured under control conditions and following reductions of PDs by means of 5 mM internal (blood side) ouabain, 0.5 mM internal and external (bathing medium) NaCN or by exhaustion of energy reserves along with a prolonged perfusion period of more than 9 h. In these experiments22Na was used as tracer. Each of the three modes of reducing transepithelial potential differences resulted in a decrease in sodium influxes from 500 1000 µmoles g-1 h-1 to 250 400 µmoles g-1 h-1. The findings suggest that sodium influx, which normally greatly exceeds efflux, was diminished by its active component. The remaining non-inhibitable influx equals efflux values. Our findings thus indicate that efflux is completely passive, while influx has — beside a passive component of efflux magnitudes — an additional active portion which is much larger than the passive component. Since ouabain is a specific inhibitor of the Na-K-ATPase, our results confirm previous findings (Siebers et al., 1985) that the basolaterally located Na-K-ATPase generates the transepithelial potential difference in the gills, which is inside negative by about 6 12 mV. Inhibition of the active portion of sodium influx by internal ouabain along with reduced PDs suggests that transepithelial PDs generated by the branchial sodium pump are the driving force for active sodium uptake in hyperregulating brackish water crabs.

  1. The effects of a competitor on the foraging behaviour of the shore crab Carcinus maenas.

    PubMed

    Chakravarti, Leela J; Cotton, Peter A

    2014-01-01

    Optimal Diet Theory suggests that individuals make foraging decisions that maximise net energy intake. Many studies provide qualitative support for this, but factors such as digestive constraints, learning, predation-risk and competition can influence foraging behaviour and lead to departures from quantitative predictions. We examined the effects of intraspecific competition within a classic model of optimal diet--the common shore crab, Carcinus maenas, feeding on the mussel, Mytilus edulis. Unexpectedly, we found that breaking time (Tb), eating time (Te), and handling time (Th) all decreased significantly in the presence of a conspecific. Reduced handling time in the presence of a competitor resulted in an increased rate of energy intake, raising the question of why crabs do not always feed in such a way. We suggest that the costs of decreased shell breaking time may be increased risk of claw damage and that crabs may be trading-off the potential loss of food to a competitor with the potential to damage their claw whilst breaking the shell more rapidly. It is well documented that prey-size selection by crabs is influenced by both the risk of claw damage and competition. However, our results are the first to demonstrate similar effects on prey handling times. We suggest that crabs maximise their long-term rate of energy intake at a scale far greater than individual foraging events and that in order to minimise claw damage, they typically break shells at a rate below their maximum. In the presence of a competitor, crabs appear to become more risk-prone and handle their food more rapidly, minimising the risk of kleptoparasitism. PMID:24691360

  2. Biochemical and physiological responses of Carcinus maenas to temperature and the fungicide azoxystrobin.

    PubMed

    Rodrigues, Elsa Teresa; Moreno, António; Mendes, Tito; Palmeira, Carlos; Pardal, Miguel Ângelo

    2015-08-01

    Research on the effects of thermal stress is currently pertinent as climate change is expected to cause more severe climate-driven events. Carcinus maenas, a recognised estuarine model organism, was selected to test temperature-dependence of azoxystrobin toxicity, a widely applied fungicide. Crabs' responses were assessed after a 10-d acclimation at different temperatures (5°C, 22°C, and 27°C) of which the last 72h were of exposure to an environmental concentration of azoxystrobin. SOD and GST activities, mitochondrial oxygen consumption rates and protein content, as well as the Coupling Index were determined. The hypothesis proposed that extreme temperatures (5°C and 27°C) and azoxystrobin would affect crabs' responses. Results showed statistically significant different effects of SOD and all oxygen rates measured promoted by temperature, and that neither 30.3μgL(-1) of azoxystrobin nor the combined effect were crab-responsive. Protein content at 5°C was statistically higher when compared with the control temperature (22°C). The Coupling Index revealed both a slight and a drastic decrease of this index promoted by 5°C and 27°C, respectively. Regarding azoxystrobin effects, at 22°C, this index only decreased slightly. However, at extreme temperatures it fell 47% at 5°C and slightly increased at 27°C. Results provided evidence that crabs' responses to cope with low temperatures were more effective than their responses to cope with high temperatures, which are expected in future climate projections. Moreover, crabs are capable of handling environmental concentrations of azoxystrobin. However, the Coupling Index showed that combined stress factors unbalance crabs' natural capability to handle a single stressor. PMID:25835271

  3. Stability of lysosomal membrane in Carcinus maenas acts as a biomarker of exposure to pharmaceuticals.

    PubMed

    Aguirre-Martínez, G V; Buratti, S; Fabbri, E; Del Valls, T A; Martín-Díaz, M L

    2013-05-01

    The presence of pharmaceuticals in the environment is now a major concern given their potential adverse effects on organisms, particularly human beings. Because the feeding style and habitat of the crab Carcinus maenas make this species vulnerable to organic contaminants, it has been used previously in ecotoxicological studies. Lysosomal membrane stability (LMS) in crabs is a general indicator of cellular well-being and can be visualized by the neutral red retention (NRR) assay. LMS in crab hemolymph has been evaluated as a cellular biomarker of adverse effects produced by exposure to pharmaceutical compounds. Crabs were exposed in the laboratory to four different pharmaceuticals for 28 days in a semistatic 24-h renewal assay. Filtered seawater was spiked every 2 days with various concentrations (from 0.1 to 50 μg · L(-1)) of caffeine, ibuprofen, carbamazepine, and novobiocin. Results showed that NRR time, measured at day 28, was significantly reduced (p < 0.05) after exposure to environmental concentrations of each pharmaceutical (caffeine = 15 μg · L(-1); carbamazepine = 1 μg · L(-1); ibuprofen = 5 μg · L(-1); and novobiocin = 0.1 μg · L(-1)) when compared with control organisms. The predicted "no environmental effect" concentration/measured environmental concentration results showed that the selected pharmaceuticals are toxic at environmental concentrations and need further assessment. LMS monitoring in crabs is a sensitive tool for evaluating exposure to concentrations of selected drugs under laboratory conditions and provides a robust tier 1 testing approach (screening biomarker) for rapid assessment of marine pollution and environmental impact assessments for analyzing pharmaceutical contamination in aquatic environments. PMID:23132752

  4. Effects of claw autotomy on green crab (Carcinus maenas) feeding rates

    NASA Astrophysics Data System (ADS)

    Tummon Flynn, Paula S.; Mellish, Cassandra L.; Pickering, Tyler R.; Quijón, Pedro A.

    2015-09-01

    The European green crab (Carcinus maenas) is a voracious non-indigenous predator and a threat to Atlantic Canada's shellfish industry. Its foraging ability, however, may be affected by the occurrence of injuries such as the loss of a cheliped (claw). Given that green crab claws are differentiated into a major crusher and a minor cutter, we argue that autotomy (the reflexive loss of a limb) affects feeding rates, and that this effect depends on which particular claw is lost. We examined the incidence of injuries in two green crab populations of the southern Gulf of St. Lawrence during July-October, 2012. Then we experimentally assessed the influence of the loss of each type of claw upon crab feeding rates over two size-classes of American oysters (Crassostrea virginica) and soft-shell clams (Mya arenaria). Field injury surveys showed that 12.4% of the green crabs collected were missing a claw (the cutter and/or crusher claw). Injury rates increased linearly with crab size, and were found to vary with location. Laboratory experiments showed that, compared to intact crabs, the loss of the crusher claw reduced oyster mortality rates by ~ 93-100%. The loss of the crusher also reduced feeding on small soft-shell clams but only temporarily. The loss of the cutter claw had little impact on green crab feeding rates on oysters and soft-shell clams of either size. Combined, these results suggest that the loss of a claw has an effect on the ability of green crabs to consume commercially important species but this effect depends on which claw is lost and which prey is targeted. It follows that injury rates should be taken into consideration when monitoring and forecasting the potential impacts of green crab populations, particularly on oyster beds.

  5. Physical and Biological Controls on the Invasion Speed of a Marine Invader with Planktonic Larvae, Illustrated with Examples From Carcinus maenas in the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Pringle, J. M.; Blakeslee, A. M.; Byers, J. E.; Roman, J.

    2008-12-01

    Existing estimates of the downstream invasion speed of newly introduced species or novel genotypes with planktonic larvae have usually found that they invade much less rapidly downstream than would be expected from the mean alongshore currents in their habitat. For example, a new, genetically-distinct population of Carcinus maenas was introduced at the northern-edge of its range in Cape Breton, Nova Scotia (Roman 2006). Recently, we have found that this newly introduced genotype is being transported south- westward along the coast by the prevailing currents, displacing established populations of C. maenas. However, the rate of southward spread of the northern genotype is much less than what we would expect from the mean currents along the Scotian Shelf and Gulf of Maine. We examine four reasons for errors in the naive estimates of the rate of spread of an introduced species or genotype from mean currents. 1) Cross-shelf shear in the alongshore currents can interact with cross-shelf dispersion of larvae to bias larval settlement towards larvae which have spent more time in the weaker nearshore currents. 2) Weakly retentive embayments and other coastal features, even if unable to retain larvae for more than a small fraction of their planktonic duration, will tend to reduce the alongshelf transports of those larvae and increase the likelihood that they remain close enough to the coast to successfully recruit. This will reduce the mean alongshore transport of the larvae that recruit. 3) Alongshore gradients in the population density of competing species/genotypes will, if the population density increases in the direction of the mean currents, tend to retard the downstream spread of an introduced species/genotype. 4) Greater relative fitness or competitiveness in the downstream genotype/species will retard the spread of the upstream genotype/species. Examples of and evidence for and against these possible explanations will be provide for C. maenas in the Gulf of Maine

  6. Effect of meal type on specific dynamic action in the green shore crab, Carcinus maenas.

    PubMed

    McGaw, Iain J; Penney, Chantelle M

    2014-05-01

    The effect of meal type on specific dynamic action was investigated in the green shore crab, Carcinus maenas. When the crabs were offered a meal of fish, shrimp, or mussel of 3 % of their body mass the duration of the SDA response and thus the resultant SDA was lower for the mussel, compared with the shrimp or fish meals. In feeding behaviour experiments the crabs consumed almost twice as much mussel compared with fish or shrimp. When the animals were allowed to feed on each meal until satiated, the differences in the SDA response were abolished. The mussel was much softer (compression test) than the fish or shrimp meal, and meal texture is known to affect the SDA response in amphibians and reptiles. When the crabs were offered a meal of homogenized fish muscle or whole fish muscle, the SDA for the homogenized meal was approximately 35 % lower. This suggested that a significant portion of the SDA budget in decapod crustaceans may be related to mechanical digestion. This is not unexpected since the foregut is supplied by over forty muscles which control the cutting and grinding movements of the gastric mill apparatus. There were slight, but significant differences in protein, lipid, moisture and total energy content of each meal type. Three prepared meals that were high in either protein, lipid or carbohydrate were offered to the crabs to determine if the nutrient content was also a contributing factor to the observed differences in the SDA. The crabs did not eat the prepared meals as readily as the natural food items and as they are messy feeders there was a large variation in the amount of food eaten. The lack of significant differences in the SDA response as a function of nutrient content was likely due to differences in amount of food eaten, which is a major factor determining the SDA response. The differences in SDA when consuming natural food items were likely due to a combination of the costs of mechanical digestion, variation in nutrient content and food

  7. Nutritional status of Carcinus maenas (Crustacea: Decapoda) influences susceptibility to contaminant exposure.

    PubMed

    Dissanayake, Awantha; Galloway, Tamara S; Jones, Malcolm B

    2008-08-11

    Using the shore crab Carcinus maenas as a model, this study tested the hypothesis that nutritional status influences susceptibility of adult crabs (>60mm carapace width (CW)) to environmental contamination. In the laboratory, crabs were either starved, given a restricted diet (fed on alternate days) or fully fed (fed each day). In addition, crabs under each feeding regime were exposed to a sublethal concentration (200microgl(-1)) of pyrene (PYR) as a model organic (PAH (polyaromatic hydrocarbon)) contaminant. Various physiological end points were measured after 7 and 14 days. Results indicated that adult shore crab physiology was relatively robust to short-term (7 days) nutritional changes as multivariate analysis (ANOSIM) showed no significant difference in shore crab physiological condition between control and pyrene-exposed crabs, irrespective of dietary feeding regime [Global R=0.018, P (%)=19.2]. After 14 days, however, starved crabs showed significant impacts to physiological condition (as revealed by multivariate analysis) [Global R=0.134, P (%)=0.1], [R=0.209, P (%)=0.1]; starved individuals had significantly lower antioxidant status (F(2,48)=5.35, P<0.01) compared to crabs under both types of feeding regime. Exposure to pyrene resulted in significantly elevated pyrene metabolite concentrations in the urine at 7 and 14 days compared with control individuals (P<0.001), validating contaminant bioavailability, and this was found for all dietary treatments. Also, exposed crabs had significantly increased protein levels (proteinuria) than controls (P<0.001) in their urine after 7 and 14 days, irrespective of dietary regime. After 7 days, pyrene-exposed crabs showed significantly increased antioxidant status (P<0.001) and cellular functioning (increased cellular viability and decreased phagocytosis) (P<0.001) compared to control crabs; however, after 14 days, antioxidant status (P<0.01) and cellular viability (P<0.001) were significantly decreased in pyrene

  8. An in situ postexposure feeding assay with Carcinus maenas for estuarine sediment-overlying water toxicity evaluations.

    PubMed

    Moreira, Susana M; Moreira-Santos, Matilde; Guilhermino, Lúcia; Ribeiro, Rui

    2006-01-01

    This study developed and evaluated a short-term sublethal in situ toxicity assay for estuarine sediment-overlying waters, with the crab Carcinus maenas (L.) based on postexposure feeding. It consisted of a 48-h in situ exposure period followed by a short postexposure feeding period (30 min). A precise method for quantifying feeding, using the Polychaeta Hediste (Nereis) diversicolor Müller as food source, was first developed. The sensitivity of the postexposure feeding response was verified by comparing it to that of lethality, upon cadmium exposure. The influence of environmental conditions prevailing during exposure (salinity, temperature, substrate, light regime, and food availability) on postexposure feeding was also addressed. The potential of this in situ assay was then investigated by deploying organisms at ten sites, located in reference and contaminated Portuguese estuaries. Organism recovery ranged between 90% and 100% and a significant postexposure feeding depression (16.3-72.7%) was observed at all contaminated sites relatively to references. PMID:16002194

  9. Biochemical responses of the shore crab (Carcinus maenas) in a eutrophic and metal-contaminated coastal system (Obidos lagoon, Portugal).

    PubMed

    Pereira, Patrícia; de Pablo, Hilda; Dulce Subida, Maria; Vale, Carlos; Pacheco, Mário

    2009-07-01

    A eutrophic and metal-contaminated coastal system (Obidos lagoon, Portugal) was monitored combining water/sediment quality parameters and Carcinus maenas biomarkers (accumulated metals, oxidative stress and biotransformation responses). Two confined branches (Barrosa and Bom-Sucesso) were surveyed and compared with a reference area. Both crab genders from Barrosa exhibited activation of hepatopancreas CAT, GPx and GST, pointing out this area as the major impacted in the lagoon. Females captured at Barrosa were more vulnerable to peroxidative damage while only males showed decreased EROD activity, reinforcing gender specificities. In general, responses were not directly attributed to metals in hepatopancreas, as supported by Principal Component Analysis (PCA). However, higher metals (Ni, Cu, Cd) and nutrients levels registered in Barrosa water were associated with the observed oxidative stress responses by PCA. Despite the difficulty to establish cause-effect relationships due to the co-occurrence of various stressors and their interactions, the adopted integrated monitoring strategy appears to be promising. PMID:19187961

  10. Expression and distribution of neuropeptides in the nervous system of the crab Carcinus maenas and their roles in environmental stress.

    PubMed

    Zhang, Yuzhuo; Buchberger, Amanda; Muthuvel, Gajanthan; Li, Lingjun

    2015-12-01

    Environmental fluctuations, such as salinity, impose serious challenges to marine animal survival. Neuropeptides, signaling molecules involved in the regulation process, and the dynamic changes of their full complement in the stress response have yet to be investigated. Here, a MALDI-MS-based stable isotope labeling quantitation strategy was used to investigate the relationship between neuropeptide expression and adaptability of Carcinus maenas to various salinity levels, including high (60 parts per thousand [p.p.t.]) and low (0 p.p.t.) salinity, in both the crustacean pericardial organ (PO) and brain. Moreover, a high salinity stress time course study was conducted. MS imaging (MSI) of neuropeptide localization in C. maenas PO was also performed. As a result of salinity stress, multiple neuropeptide families exhibited changes in their relative abundances, including RFamides (e.g. APQGNFLRFamide), RYamides (e.g. SSFRVGGSRYamide), B-type allatostatins (AST-B; e.g. VPNDWAHFRGSWamide), and orcokinins (e.g. NFDEIDRSSFGFV). The MSI data revealed distribution differences in several neuropeptides (e.g. SGFYANRYamide) between color morphs, but salinity stress appeared to not have a major effect on the localization of the neuropeptides.

  11. Microtopography of the eye surface of the crab Carcinus maenas: an atomic force microscope study suggesting a possible antifouling potential.

    PubMed

    Greco, G; Lanero, T Svaldo; Torrassa, S; Young, R; Vassalli, M; Cavaliere, A; Rolandi, R; Pelucchi, E; Faimali, M; Davenport, J

    2013-07-01

    Marine biofouling causes problems for technologies based on the sea, including ships, power plants and marine sensors. Several antifouling techniques have been applied to marine sensors, but most of these methodologies are environmentally unfriendly or ineffective. Bioinspiration, seeking guidance from natural solutions, is a promising approach to antifouling. Here, the eye of the green crab Carcinus maenas was regarded as a marine sensor model and its surface characterized by means of atomic force microscopy. Engineered surface micro- and nanotopography is a new mechanism found to limit biofouling, promising an effective solution with much reduced environmental impact. Besides giving a new insight into the morphology of C. maenas eye and its characterization, our study indicates that the eye surface probably has antifouling/fouling-release potential. Furthermore, the topographical features of the surface may influence the wettability properties of the structure and its interaction with organic molecules. Results indicate that the eye surface micro- and nanotopography may lead to bioinspired solutions to antifouling protection. PMID:23635491

  12. Expression and distribution of neuropeptides in the nervous system of the crab Carcinus maenas and their roles in environmental stress.

    PubMed

    Zhang, Yuzhuo; Buchberger, Amanda; Muthuvel, Gajanthan; Li, Lingjun

    2015-12-01

    Environmental fluctuations, such as salinity, impose serious challenges to marine animal survival. Neuropeptides, signaling molecules involved in the regulation process, and the dynamic changes of their full complement in the stress response have yet to be investigated. Here, a MALDI-MS-based stable isotope labeling quantitation strategy was used to investigate the relationship between neuropeptide expression and adaptability of Carcinus maenas to various salinity levels, including high (60 parts per thousand [p.p.t.]) and low (0 p.p.t.) salinity, in both the crustacean pericardial organ (PO) and brain. Moreover, a high salinity stress time course study was conducted. MS imaging (MSI) of neuropeptide localization in C. maenas PO was also performed. As a result of salinity stress, multiple neuropeptide families exhibited changes in their relative abundances, including RFamides (e.g. APQGNFLRFamide), RYamides (e.g. SSFRVGGSRYamide), B-type allatostatins (AST-B; e.g. VPNDWAHFRGSWamide), and orcokinins (e.g. NFDEIDRSSFGFV). The MSI data revealed distribution differences in several neuropeptides (e.g. SGFYANRYamide) between color morphs, but salinity stress appeared to not have a major effect on the localization of the neuropeptides. PMID:26475201

  13. Biology, population dynamics and secondary production of the green crab Carcinus maenas (L.) in a temperate estuary

    NASA Astrophysics Data System (ADS)

    Baeta, A.; Cabral, H. N.; Neto, J. M.; Marques, J. C.; Pardal, M. A.

    2005-10-01

    The biological features, population dynamics and secondary production of Carcinus maenas were studied between June 2003 and June 2004 in four areas within the Mondego estuary, Portugal. Benthic samples were collected monthly, during the night, at high water of spring tides using a 2-m beam trawl, and plankton samples were collected monthly, during the day, at high tide with a Bongo net. Only the first zoeae stage of C. maenas larvae was found in the plankton; it was collected at all sampling stations throughout the year. A continuous pattern of benthic recruitment was observed in the upstream areas of the estuary with the highest peaks occurring in the spring 2004. Females carrying eggs were also caught through the year, although mainly in downstream areas. Juveniles' sex-ratio was favourable to males at almost all the sites sampled. Ventral carapace colour varied between green and orange-red, with the proportion of the green morphotype increasing with the increasing distance from the mouth of the estuary. The proportion of crabs in moult also increased from downstream to upstream areas. For both sexes the crab population showed a similar size structure throughout the year. The upstream areas of the estuary were characterized by the dominance of juveniles, with adults migrating to downstream areas. The average annual production of C. maenas, P (growth production), was estimated at 0.08 g m -2 y -1 AFDW, and the average annual biomass ( B¯) was estimated at 0.058 g m -2, resulting in a P/B¯ ratio of 1.4.

  14. Low salinity enhances NI-mediated oxidative stress and sub-lethal toxicity to the green shore crab (Carcinus maenas).

    PubMed

    Blewett, Tamzin A; Wood, Chris M

    2015-12-01

    Nickel (Ni) is a metal of environmental concern, known to cause toxicity to freshwater organisms by impairing ionoregulation and/or respiratory gas exchange, and by inducing oxidative stress. However, little is known regarding how nickel toxicity is influenced by salinity. In the current study we investigated the salinity-dependence and mechanisms of sub-lethal Ni toxicity in a euryhaline crab (Carcinus maenas). Crabs were acclimated to three experimental salinities--20, 60 and 100% seawater (SW)--and exposed to 3mg/L Ni for 24h or 96 h. Tissues were dissected for analysis of Ni accumulation, gills were taken for oxidative stress analysis (catalase activity and protein carbonyl content), haemolymph ions were analysed for ionoregulatory disturbance, and oxygen consumption was determined in exercised crabs after 96 h of Ni exposure. Total Ni accumulation was strongly dependant on salinity, with crabs from 20% SW displaying the highest tissue Ni burdens after both 24 and 96-h exposures. After 96 h of exposure, the highest accumulation of Ni occurred in the posterior (ionoregulatory) gills at the lowest salinity, 20% SW. Posterior gill 8 exhibited elevated protein carbonyl levels and decreased catalase activity after Ni exposure, but only in 20% SW. Similarly, decreased levels of haemolymph Mg and K and an increased level of Ca were recorded but only in crabs exposed to Ni for 96 h in 20% SW. Oxygen consumption after exercise was also inhibited in crabs exposed to Ni in 20% SW. These data show for the first time the simultaneous presence of all three modes of sub-lethal Ni toxicity in exposed animals, and indicate a strong salinity dependence of sub-lethal Ni toxicity to the euryhaline crab, C. maenas, a pattern that corresponded to tissue Ni accumulation. PMID:26233920

  15. Regulation of sodium in the shore crab Carcinus maenas, adapted to environments of constant and changing salinities

    NASA Astrophysics Data System (ADS)

    Siebers, D.; Winkler, A.; Leweck, K.; Madian, A.

    1983-09-01

    The activity of Na-K-ATPase was determined in the posterior gills of the shore crab Carcinus maenas during a period following transfer from 35 to 10 ‰ salinity and vice versa at 15 °C. After transfer from high to low salinity, Na-K-ATPase activity increased from 3.2 to 7.0 μmoles Pi mg protein-1 h-1 within a period of 2 to 3 weeks. Transfer of crabs from low to high salinity resulted in reduction of activity from 7.4 to 4.5 μmoles Pi mg protein-1 h-1 within about the same period. The relatively slow response following salinity change indicates that the amounts of Na-K-ATPase in the gills may play a role in hyperionic Na regulation in relatively constant brackish-water environments. Instant responses to salinity result from activation and inhibition of Na-K-ATPase activity by Na. Gill Na-K-ATPase is activated by the Na concentration of the incubation medium to attain a steep maximum at about 75 mM Na, which corresponds to the lowest environmental Na levels tolerated by C. maenas equivalent to a salinity of ca 6 ‰. Activity greatly decreased towards higher Na levels, equivalent to the salinity of normal sea water, at which hyperregulation no longer occurs. Selective addition of either Na or Cl to brackish water of 9 ‰ S resulted in effective hyperregulation of the non-increased ion, and passive distribution between medium and blood of the increased ion. These data indicate that under appropriate conditions the normally coupled transport of Na and Cl may be uncoupled and take place independently of each other.

  16. Low salinity enhances NI-mediated oxidative stress and sub-lethal toxicity to the green shore crab (Carcinus maenas).

    PubMed

    Blewett, Tamzin A; Wood, Chris M

    2015-12-01

    Nickel (Ni) is a metal of environmental concern, known to cause toxicity to freshwater organisms by impairing ionoregulation and/or respiratory gas exchange, and by inducing oxidative stress. However, little is known regarding how nickel toxicity is influenced by salinity. In the current study we investigated the salinity-dependence and mechanisms of sub-lethal Ni toxicity in a euryhaline crab (Carcinus maenas). Crabs were acclimated to three experimental salinities--20, 60 and 100% seawater (SW)--and exposed to 3mg/L Ni for 24h or 96 h. Tissues were dissected for analysis of Ni accumulation, gills were taken for oxidative stress analysis (catalase activity and protein carbonyl content), haemolymph ions were analysed for ionoregulatory disturbance, and oxygen consumption was determined in exercised crabs after 96 h of Ni exposure. Total Ni accumulation was strongly dependant on salinity, with crabs from 20% SW displaying the highest tissue Ni burdens after both 24 and 96-h exposures. After 96 h of exposure, the highest accumulation of Ni occurred in the posterior (ionoregulatory) gills at the lowest salinity, 20% SW. Posterior gill 8 exhibited elevated protein carbonyl levels and decreased catalase activity after Ni exposure, but only in 20% SW. Similarly, decreased levels of haemolymph Mg and K and an increased level of Ca were recorded but only in crabs exposed to Ni for 96 h in 20% SW. Oxygen consumption after exercise was also inhibited in crabs exposed to Ni in 20% SW. These data show for the first time the simultaneous presence of all three modes of sub-lethal Ni toxicity in exposed animals, and indicate a strong salinity dependence of sub-lethal Ni toxicity to the euryhaline crab, C. maenas, a pattern that corresponded to tissue Ni accumulation.

  17. Recruitment of shore crabs Carcinus maenas on tidal flats: Mussel clumps as an important refuge for juveniles

    NASA Astrophysics Data System (ADS)

    Thiel, M.; Dernedde, T.

    1994-06-01

    During the late summer and early fall, juvenile shore crabs ( Carcinus maenas L.) occurred in high abundances in mussel clumps scattered on tidal flats of the Wadden Sea. Abundances were much lower on bare tidal flats without mussel clumps and decreased substantially from July to November, whereas numbers in mussel clumps remained high. Large crabs left the tidal flats in early fall, whereas juveniles undertook tidal migrations only in the late fall. In March very few shore crabs were found in the intertidal area. The size of juvenile shore crabs living between mussels did not increase significantly during fall. On the bare tidal flats surrounding the mussels, a size increase was observed. Mussel beds and mussel clumps serve as a spatial refuge for the early benthic phases of juvenile shore crabs. Between mussels they can hide effectively from their epibenthic predators. Juvenile shore crabs do not leave the intertidal area and the mussel habitats before their major predators have left the area. Mussel clumps scattered over the tidal flats may be a critical refuge for juvenile shore crabs settling on tidal flats. Intensified efforts in mussel culturing in the European Wadden Sea during recent decades may have caused an increased abundance of mussel clumps on tidal flats, thus enhancing habitat availability for some mussel-clump inhabitants.

  18. Ingestion of Plastic Microfibers by the Crab Carcinus maenas and Its Effect on Food Consumption and Energy Balance.

    PubMed

    Watts, Andrew J R; Urbina, Mauricio A; Corr, Shauna; Lewis, Ceri; Galloway, Tamara S

    2015-12-15

    Microscopic plastic fragments (<5 mm) are a worldwide conservation issue, polluting both coastal and marine environments. Fibers are the most prominent plastic type reported in the guts of marine organisms, but their effects once ingested are unknown. This study investigated the fate of polypropylene rope microfibers (1-5 mm in length) ingested by the crab Carcinus maenas and the consequences for the crab's energy budget. In chronic 4 week feeding studies, crabs that ingested food containing microfibers (0.3-1.0% plastic by weight) showed reduced food consumption (from 0.33 to 0.03 g d(-1)) and a significant reduction in energy available for growth (scope for growth) from 0.59 to -0.31 kJ crab d(-1) in crabs fed with 1% plastic. The polypropylene microfibers were physically altered by their passage through the foregut and were excreted with a smaller overall size and length and amalgamated into distinctive balls. These results support of the emerging paradigm that a key biological impact of microplastic ingestion is a reduction in energy budgets for the affected marine biota. We also provide novel evidence of the biotransformations that can affect the plastics themselves following ingestion and excretion. PMID:26529464

  19. Unravelling polar lipids dynamics during embryonic development of two sympatric brachyuran crabs (Carcinus maenas and Necora puber) using lipidomics.

    PubMed

    Rey, Felisa; Alves, Eliana; Melo, Tânia; Domingues, Pedro; Queiroga, Henrique; Rosa, Rui; Domingues, M Rosário M; Calado, Ricardo

    2015-01-01

    Embryogenesis is an important stage of marine invertebrates with bi-phasic life cycles, as it conditions their larval and adult life. Throughout embryogenesis, phospholipids (PL) play a key role as an energy source, as well as constituents of biological membranes. However, the dynamics of PL during embryogenesis in marine invertebrates is still poorly studied. The present work used a lipidomic approach to determine how polar lipid profiles shift during embryogenesis in two sympatric estuarine crabs, Carcinus maenas and Necora puber. The combination of thin layer chromatography, liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry allowed us to achieve an unprecedented resolution on PL classes and molecular species present on newly extruded embryos (stage 1) and those near hatching (stage 3). Embryogenesis proved to be a dynamic process, with four PL classes being recorded in stage 1 embryos (68 molecular species in total) and seven PL classes at stage 3 embryos (98 molecular species in total). The low interspecific difference recorded in the lipidomic profiles of stage 1 embryos appears to indicate the existence of similar maternal investment. The same pattern was recorded for stage 3 embryos revealing a similar catabolism of embryonic resources during incubation for both crab species. PMID:26419891

  20. Comparison of protein-extraction methods for gills of the shore crab, Carcinus maenas (L.), and application to 2DE.

    PubMed

    Panchout, François; Letendre, Julie; Bultelle, Florence; Denier, Xavier; Rocher, Béatrice; Chan, Philippe; Vaudry, David; Durand, Fabrice

    2013-12-01

    As it is well-established that protein extraction constitutes a crucial step for two-dimensional electrophoresis (2DE), this work was done as a prerequisite to further the study of alterations in the proteome in gills of the shore crab Carcinus maenas under contrasted environmental conditions. Because of the presence of a chitin layer, shore crab gills have an unusual structure. Consequently, they are considered as a hard tissue and represent a challenge for optimal protein extraction. In this study, we compared three published extraction procedures for subsequent applications to 2DE: the first one uses homogenization process, the second one included an additional TCA-acetone precipitation step, and finally, the third one associated grinding in liquid nitrogen (N2) and TCA-acetone precipitation. Extracted proteins were then resolved using 1DE and 2DE. Although interesting patterns were obtained using 1DE with the three methods, only the one involving grinding in liquid N2 and TCA-acetone precipitation led to proper resolution after 2DE, showing a good level of reproducibility at technical (85%) and biological (84%) levels. This last method is therefore proposed for analysis of gill proteomes in the shore crab. PMID:24294114

  1. Amount and metal composition of midgut gland metallothionein in shore crabs (Carcinus maenas) after exposure to cadmium in the food.

    PubMed

    Pedersen, Knud Ladegaard; Bach, Louise Thornhøj; Bjerregaard, Poul

    2014-05-01

    Accumulation of cadmium in aquatic invertebrates may compromise human food safety and anthropogenic additions of cadmium to coastal areas cause concern. Induction of crustacean metallothionein has been suggested as a useful biomarker for contamination of the aquatic environment with cadmium. We investigated how exposure to low concentrations of cadmium in the food affects the subcellular binding of cadmium with the shore crab Carcinus maenas as model organism. Approximately 80% of the assimilated cadmium was bound in the soluble fraction of the midgut gland and of this, 82% was found in the metallothionein fraction. Metallothionein synthesis was only induced at the highest exposure level. However, the number of cadmium atoms bound per molecule of metallothionein increased linearly with exposure, from approximately 0.18 in the control group to 1.4 in a group administered food containing 5.1 μg Cd g(-1). We noted a marked interaction between the presence of copper and zinc in the midgut gland and the binding of cadmium. The usefulness of crustacean midgut gland metallothionein as a biomarker for cadmium exposure at modest levels was questioned since exposures at levels producing significant increases in the tissue contents of the metal did not result in elevated concentrations of metallothionein in the midgut gland. PMID:24685622

  2. On the morphology of the central nervous system in larval stages of Carcinus maenas L. (Decapoda, Brachyura)

    NASA Astrophysics Data System (ADS)

    Harzsch, S.; Dawirs, R. R.

    1993-02-01

    We investigated the morphology of the central nervous system throughout the larval development of Carcinus maenas. For that purpose single larvae were reared in the laboratory from hatching through metamorphosis. Complete series of whole mout semithin sections were obtained from individuals of all successive larval stages and analysed with a light microscope. Morphological feature and spatial arrangement of discernable neural cell clusters, fibre tracts and neuropile are described and compared with the adult pattern. We found that most of the morphological features characterizing the adult nervous system are already present in the zoea-1. Nevertheless, there are marked differences with respect to the arrangement of nerve cell bodies, organization of cerebral neuropile, and disposition of ganglia in the ventral nerve cord. It appears that complexity of the central nervous neuropile is selectively altered during postmetamorphotic development, probably reflecting adaptive changes of sensory-motor integration in response to behavioural maturation. In contrast, during larval development there was little change in the overall structural organization of the central nervous system despite some considerable growth. However, the transition from zoea-4 to megalopa brings about multiple fundamental changes in larval morphology and behavioural pattern. Since central nervous integration should properly adapt to the altered behavioural repertoire of the megalopa, it seems necessary to ask in which respect synaptic rearrangement might characterize development of the central nervous system.

  3. Sertraline accumulation and effects in the estuarine decapod Carcinus maenas: importance of the history of exposure to chemical stress.

    PubMed

    Rodrigues, Aurélie P; Santos, Lúcia H M L M; Ramalhosa, Maria João; Delerue-Matos, Cristina; Guimarães, Laura

    2015-01-01

    Sertraline is widely prescribed worldwide and frequently detected in aquatic systems. There is, however, a remarkable gap of information on its potential impact on estuarine and coastal invertebrates. This study investigated sertraline accumulation and effects in Carcinus maenas. Crabs from a moderately contaminated (Lima) and a low-impacted (Minho) estuary were exposed to environmental and high levels of sertraline (0.05, 5, 500 μg L(-1)). A battery of biomarkers related to sertraline mode of action was employed to assess neurotransmission, energy metabolism, biotransformation and oxidative stress pathways. After a seven-day exposure, sertraline accumulation in crabs' soft tissues was found in Lima (5 μg L(-1): 15.3 ng L(-1) ww; 500 μg L(-1): 1010 ng L(-1) ww) and Minho (500 μg L(-1): 605 ng L(-1) ww) animals. Lima crabs were also more sensitive to sertraline than those from Minho, exhibiting decreased acetylcholinesterase activity, indicative of ventilatory and locomotory dysfunction, inhibition of anti-oxidant enzymes and increased oxidative damage at ≥ 0.05 μg L(-1). The Integrated Biomarker Response (IBR) index indicated their low health status. In addition, Minho crabs showed non-monotonic responses of acetylcholinesterase suggestive of hormesis. The results pointed an influence of the exposure history on differential sensitivity to sertraline and the need to perform evaluations with site-specific ecological receptors to increase relevance of risk estimations when extrapolating from laboratory to field conditions. PMID:25305364

  4. The effect of dietary chitin supplementation on the survival and immune reactivity of the shore crab, Carcinus maenas.

    PubMed

    Powell, Adam; Rowley, Andrew F

    2007-05-01

    Adult male shore crabs (Carcinus maenas) were maintained on a fish-based diet supplemented with 0, 5 or 10% chitin for 11 weeks. Significantly greater mortality was found during this period in the control group (0% chitin) than those fed 10% chitin. Crabs fed 5 or 10% chitin had lower numbers of cultivatable bacteria in the hepatopancreas than those on the basal diet alone. The addition of chitin had no significant effect on the serum concentrations of protein and glucose, and the levels of glycogen in the hepatopancreas. The total number of circulating hemocytes in the blood was unaffected by the addition of chitin to the diet, however, at week 6 there were significantly more hyaline hemocytes in those crabs fed 10% chitin than the control group. The in vitro phagocytic activity of hemocytes was unaffected by chitin supplementation and crabs challenged with Vibrio alginolyticus showed a similar pattern of susceptibility in the three dietary groups (0, 5 or 10% chitin). Overall although crabs on a chitin-supplemented diet showed greater survival, this was not explained in terms of elevation in the cellular defences of these animals. The enhanced survival of crabs-fed chitin is probably as a result of the removal of potentially pathogenic bacteria from the hepatopancreas. Because chitin appears to 'purge' bacteria from the gut, this may prove to be a useful addition to diets on animals undergoing oral probiotic treatment. PMID:17289410

  5. Accumulation and depuration of okadaic acid esters in the European green crab (Carcinus maenas) during a feeding study.

    PubMed

    Jørgensen, Kevin; Cold, Ulrik; Fischer, Knud

    2008-03-01

    Soft shell crab is a seafood delicacy in many parts of the world. In Denmark, it has been investigated whether a commercial production of soft shell European green crabs (Carcinus maenas) would be feasible. In relation to this, a feeding study was performed to examine if occurrence of DSP toxins in the product could be a food safety problem. The crabs were fed with mussels containing DSP toxins (2500 microg total okadaic acid equivalents/kg) for 17 days and then fasted for 19 days. The content of total okadaic acid equivalents in the digestive organs was on average 27 times higher than the corresponding content in the body meat. The highest level of total okadaic acid equivalents measured was 12 microg/kg in body meat and 503 microg/kg in digestive organs. The results show that the content of DSP toxins in a commercial product of soft shell European green crab (without digestive organs) could be regarded as negligible. PMID:17983637

  6. Environmental monitoring of Domingo Rubio stream (Huelva Estuary, SW Spain) by combining conventional biomarkers and proteomic analysis in Carcinus maenas.

    PubMed

    Montes Nieto, Rafael; García-Barrera, Tamara; Gómez-Ariza, José-Luis; López-Barea, Juan

    2010-02-01

    Element load, conventional biomarkers and altered protein expression profiles were studied in Carcinus maenas crabs, to assess contamination of "Domingo Rubio" stream, an aquatic ecosystem that receives pyritic metals, industrial contaminants, and pesticides. Lower antioxidative activities - glucose-6-phosphate and 6-phosphogluconate dehydrogenases, catalase - were found in parallel to higher levels of damaged biomolecules - malondialdehyde, oxidized glutathione -, due to oxidative lesions promoted by contaminants, as the increased levels of essential - Zn, Cu, Co - and nonessential - Cr, Ni, Cd - elements. Utility of Proteomics to assess environmental quality was confirmed, especially after considering the six proteins identified by de novo sequencing through capLC-muESI-ITMS/MS and homology search on databases. They include tripartite motif-containing protein 11 and ATF7 transcription factor (upregulated), plus CBR-NHR-218 nuclear hormone receptor, two components of the ABC transporters and aldehyde dehydrogenase (downregulated). These proteins could be used as novel potential biomarkers of the deleterious effects of pollutants present in the area. PMID:19815320

  7. Unravelling polar lipids dynamics during embryonic development of two sympatric brachyuran crabs (Carcinus maenas and Necora puber) using lipidomics

    PubMed Central

    Rey, Felisa; Alves, Eliana; Melo, Tânia; Domingues, Pedro; Queiroga, Henrique; Rosa, Rui; Domingues, M. Rosário M.; Calado, Ricardo

    2015-01-01

    Embryogenesis is an important stage of marine invertebrates with bi-phasic life cycles, as it conditions their larval and adult life. Throughout embryogenesis, phospholipids (PL) play a key role as an energy source, as well as constituents of biological membranes. However, the dynamics of PL during embryogenesis in marine invertebrates is still poorly studied. The present work used a lipidomic approach to determine how polar lipid profiles shift during embryogenesis in two sympatric estuarine crabs, Carcinus maenas and Necora puber. The combination of thin layer chromatography, liquid chromatography – mass spectrometry and gas chromatography – mass spectrometry allowed us to achieve an unprecedented resolution on PL classes and molecular species present on newly extruded embryos (stage 1) and those near hatching (stage 3). Embryogenesis proved to be a dynamic process, with four PL classes being recorded in stage 1 embryos (68 molecular species in total) and seven PL classes at stage 3 embryos (98 molecular species in total). The low interspecific difference recorded in the lipidomic profiles of stage 1 embryos appears to indicate the existence of similar maternal investment. The same pattern was recorded for stage 3 embryos revealing a similar catabolism of embryonic resources during incubation for both crab species. PMID:26419891

  8. Ingestion of Plastic Microfibers by the Crab Carcinus maenas and Its Effect on Food Consumption and Energy Balance.

    PubMed

    Watts, Andrew J R; Urbina, Mauricio A; Corr, Shauna; Lewis, Ceri; Galloway, Tamara S

    2015-12-15

    Microscopic plastic fragments (<5 mm) are a worldwide conservation issue, polluting both coastal and marine environments. Fibers are the most prominent plastic type reported in the guts of marine organisms, but their effects once ingested are unknown. This study investigated the fate of polypropylene rope microfibers (1-5 mm in length) ingested by the crab Carcinus maenas and the consequences for the crab's energy budget. In chronic 4 week feeding studies, crabs that ingested food containing microfibers (0.3-1.0% plastic by weight) showed reduced food consumption (from 0.33 to 0.03 g d(-1)) and a significant reduction in energy available for growth (scope for growth) from 0.59 to -0.31 kJ crab d(-1) in crabs fed with 1% plastic. The polypropylene microfibers were physically altered by their passage through the foregut and were excreted with a smaller overall size and length and amalgamated into distinctive balls. These results support of the emerging paradigm that a key biological impact of microplastic ingestion is a reduction in energy budgets for the affected marine biota. We also provide novel evidence of the biotransformations that can affect the plastics themselves following ingestion and excretion.

  9. Unravelling polar lipids dynamics during embryonic development of two sympatric brachyuran crabs (Carcinus maenas and Necora puber) using lipidomics.

    PubMed

    Rey, Felisa; Alves, Eliana; Melo, Tânia; Domingues, Pedro; Queiroga, Henrique; Rosa, Rui; Domingues, M Rosário M; Calado, Ricardo

    2015-09-30

    Embryogenesis is an important stage of marine invertebrates with bi-phasic life cycles, as it conditions their larval and adult life. Throughout embryogenesis, phospholipids (PL) play a key role as an energy source, as well as constituents of biological membranes. However, the dynamics of PL during embryogenesis in marine invertebrates is still poorly studied. The present work used a lipidomic approach to determine how polar lipid profiles shift during embryogenesis in two sympatric estuarine crabs, Carcinus maenas and Necora puber. The combination of thin layer chromatography, liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry allowed us to achieve an unprecedented resolution on PL classes and molecular species present on newly extruded embryos (stage 1) and those near hatching (stage 3). Embryogenesis proved to be a dynamic process, with four PL classes being recorded in stage 1 embryos (68 molecular species in total) and seven PL classes at stage 3 embryos (98 molecular species in total). The low interspecific difference recorded in the lipidomic profiles of stage 1 embryos appears to indicate the existence of similar maternal investment. The same pattern was recorded for stage 3 embryos revealing a similar catabolism of embryonic resources during incubation for both crab species.

  10. Biochemical effects in crabs (Carcinus maenas) and contamination levels in the Bizerta Lagoon: an integrated approach in biomonitoring of marine complex pollution.

    PubMed

    Ben-Khedher, Sana; Jebali, Jamel; Kamel, Naouel; Banni, Mohamed; Rameh, Mohamed; Jrad, Amel; Boussetta, Hamadi

    2013-04-01

    The biochemical effects in Carcinus maenas and contamination levels in seawater and sediments of Bizerta Lagoon (northeast of Tunisia) were investigated. The levels of metals and hydrocarbons were higher in seawater and sediments in Menzel Bourguiba and Cimentery in February and July than in the other sampling sites. Differences among sites for glutathione S-transferase, catalase, acetylcholinesterase activities, and the content of lipid peroxidation and metallothioneins in two important organs which accumulated contaminants (the gills and the digestive gland) of the C. maenas were found and possibly related to differences in metal and hydrocarbon levels. The seasonal variation of biomarkers was possibly associated with chemical contamination and also with the high fluctuation of physico-chemical characteristics of the sites. The integrated biomarker response values found in the five sites is in good agreement with hydrocarbon and trace metal concentrations detected in the water and sediments of the stressful places where crabs are living. PMID:22976048

  11. Biochemical effects in crabs (Carcinus maenas) and contamination levels in the Bizerta Lagoon: an integrated approach in biomonitoring of marine complex pollution.

    PubMed

    Ben-Khedher, Sana; Jebali, Jamel; Kamel, Naouel; Banni, Mohamed; Rameh, Mohamed; Jrad, Amel; Boussetta, Hamadi

    2013-04-01

    The biochemical effects in Carcinus maenas and contamination levels in seawater and sediments of Bizerta Lagoon (northeast of Tunisia) were investigated. The levels of metals and hydrocarbons were higher in seawater and sediments in Menzel Bourguiba and Cimentery in February and July than in the other sampling sites. Differences among sites for glutathione S-transferase, catalase, acetylcholinesterase activities, and the content of lipid peroxidation and metallothioneins in two important organs which accumulated contaminants (the gills and the digestive gland) of the C. maenas were found and possibly related to differences in metal and hydrocarbon levels. The seasonal variation of biomarkers was possibly associated with chemical contamination and also with the high fluctuation of physico-chemical characteristics of the sites. The integrated biomarker response values found in the five sites is in good agreement with hydrocarbon and trace metal concentrations detected in the water and sediments of the stressful places where crabs are living.

  12. Effect of crab size and habitat type on the locomotory activity of juvenile shore crabs, Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Almeida, Maria João; Flores, Augusto A. V.; Queiroga, Henrique

    2008-12-01

    Post-settlement processes are a major focus in the study of the dynamics of marine populations and communities. Post-settlement movement of juveniles is an important, but often ignored, process which affects local predator-prey and competitive interactions. We used benthic suction sampling and pitfall traps to examine density and locomotory activity of Carcinus maenas juveniles in different intertidal habitat types in the Rio Mira Estuary, Portugal, to better understand intra-specific interactions in a system where density-dependent processes are known to regulate population dynamics. As expected, significantly higher densities of juvenile shore crabs were found from bare mud compared to densely vegetated habitats. At the time of sampling, small and intermediate stages together outnumbered by far the larger juveniles. Conversely, larger crabs were much more frequent than smaller ones in traps. A locomotory index (LI), i.e. the ratio between crab catch in pitfall traps and their density within their moving range, is proposed as a measure of movement. LI analyses indicated that: (1) movement is an order of magnitude higher in large than small juveniles and much higher in sparse than dense vegetation cover; (2) activity of small juveniles is mostly crepuscular, regardless of vegetation cover; and (3) movement of large juveniles is very limited in dense Zostera patches, but very high in sparsely vegetated areas, during the day and night. These results suggest that small juveniles are relatively protected under dense vegetation cover due to lower mobility of larger crabs, and provide evidence of temporal segregation of activity windows between juvenile crabs of different sizes, which may be a key mechanism to reduce cannibalism and therefore increase the carrying capacity of nursery habitats.

  13. Seasonal differences in the physiology of Carcinus maenas (Crustacea: Decapoda) from estuaries with varying levels of anthropogenic contamination

    NASA Astrophysics Data System (ADS)

    Dissanayake, Awantha; Galloway, Tamara S.; Jones, Malcolm B.

    2011-07-01

    This study reports the seasonal variability in aspects of the physiology of the shore crab Carcinus maenas from three estuaries in South-west England, each with varying anthropogenic inputs: Avon Estuary ('relatively low' impact), Yealm Estuary ('intermediate' impact) and Plym Estuary ('relatively high' impact). Crabs collected over 12 months from the Avon had a significantly 'lower' physiological condition in winter and spring compared to summer and autumn; in particular, haemocyte phagocytic capability (a general indicator of immune function) was significantly higher in winter and spring compared to summer and autumn, and total haemolymph antioxidant status (an indicator of oxidative stress) was significantly lower in winter compared to the remainder of the year. Potentially, shore crabs may be more susceptible to the effects of contaminant exposure, such as increased immunotoxicity (thus, reduction of immune function) and/or oxyradicals (or reactive oxygen species) exposure) especially in seasons of increased susceptibility i.e. summer/autumn (lower phagocytic capability) and winter (lowest antioxidant function). As the Avon was taken to represent the 'reference' site, this pattern is considered to reflect the 'normal' seasonal variability in shore crab physiology. Shore crab physiological condition from the 'relatively high' impact estuary (Plym) revealed increased cellular viability and antioxidant status in autumn and winter compared with that of the 'standard' pattern (Avon) However, crabs from the intermediate impact estuary (Yealm) only demonstrated significant physiological differences in summer as shown by a lower cellular viability. All crabs had been exposed to PAHs (confirmed by the presence of PAH metabolites in their urine) which may account for the observed differences in shore crab physiology. In conclusion, to aid understanding of the potential contaminant impacts on biota it is imperative that the 'normal' seasonal variability of physiological

  14. Early responses measured in the brachyuran crab Carcinus maenas exposed to carbamazepine and novobiocin: application of a 2-tier approach.

    PubMed

    Aguirre-Martínez, G V; Del Valls, T A; Martín-Díaz, M L

    2013-11-01

    One of the main consequences of the constant input of pharmaceuticals to the aquatic environment is that biota might develop unknown chronic effects, thus affecting their health even at low concentrations. The aim of this study is to evaluate the health status of Carcinus maenas employing a 2-tier approach, after 28 days of exposure to carbamazepine (CBZ) and novobiocin (NOV) at 0.1, 1, 10 and 50µgL(-1). Lysosomal membrane stability (LMS) is employed in tier 1. In tier 2 was applied a battery of biomarkers of exposure and effect (ethoxyresorufin O-deethylase (EROD), dibenzyl flourescein dealkylase (DBF), glutathione S-transferase (GST), glutathione peroxidase (GPx), lipid peroxidation (LPO) and DNA adducts) measured in gill, hepatopancreas, muscle and gonad tissues. Results show a dose-dependent effect. LMS in crabs exposed to environmental concentrations of pharmaceuticals was significantly lower compared to controls (p<0.05), indicating their stressed status. EROD activity was induced significantly (p<0.05) in all tissues by NOV (10-50µgL(-1)). DBF activity was induced significantly (p<0.05) in gill and hepatopancreas tissues by CBZ (10-50µgL(-1)). GST activity was activated in all tissues of crabs exposed to the highest concentrations tested (p<0.05). All tissues showed induction of GPX activity after exposure to selected drugs (p<0.05). LPO was activated in gill and hepatopancreas tissues by the pharmaceuticals at 50µgL(-1) (p<0.05). Crabs exposed to NOV (50µgL(-1)) presented DNA damage in gill and hepatopancreas tissues (p<0.05). Environmental concentrations of these pharmaceuticals have a measurable effect on the biomarkers studied. The 2-tier approach applied might be a suitable tool for the assessment of sublethal responses in crabs exposed to pharmaceuticals in the marine environment. PMID:23916015

  15. Effect of temperature on the spoilage rate of whole, unprocessed crabs: Carcinus maenas, Necora puber and Cancer pagurus.

    PubMed

    Robson, Anthony A; Kelly, Maeve S; Latchford, John W

    2007-06-01

    Shelf life of whole, initially live, crabs depended primarily on the storage conditions and the time at which death occurred. Large differences in the time that individual crab species survived particular storage conditions resulted in wide variations in shelf-life. Bacterial spoilage of Carcinus maenas, Necora puber and Cancer pagurus, measured using aerobic plate counts, indicated that on ice at 4 degrees C whole unprocessed crabs had a shelf life approximately 9-11 days, at 4 degrees C approximately 13-29 days, in simulated supermarket conditions of sale approximately 5-7 days and at 20 degrees C approximately 2-16 days. Storage of whole unprocessed crabs chilled at 4 degrees C considerably extended shelf life compared to crabs stored on ice. Live crabs stored on ice died within 24h, most likely due to thermal shock and their early death was responsible for their more rapid increase in bacterial numbers compared to crabs stored at 4 degrees C. No growth of bacteria occurred in the flesh of live crabs stored at 4 degrees C for between 128 and 504 h. Crab flesh quality deteriorated prior to maximum shelf-life (defined as the time at which bacterial load reached log 5 cfu/g crabmeat) in some instances. The best compromise between high crabmeat yield and long shelf-life is likely to be to transport crabs at 4 degrees C live to market where they could be stored live at 4 degrees C without spoilage for 2 weeks before placed on ice at 4 degrees C, with a potential maximum shelf life of approximately 24 days. PMID:17189768

  16. Comparative brain architecture of the European shore crab Carcinus maenas (Brachyura) and the common hermit crab Pagurus bernhardus (Anomura) with notes on other marine hermit crabs.

    PubMed

    Krieger, Jakob; Sombke, Andy; Seefluth, Florian; Kenning, Matthes; Hansson, Bill S; Harzsch, Steffen

    2012-04-01

    The European shore crab Carcinus maenas and the common hermit crab Pagurus bernhardus are members of the sister taxa Brachyura and Anomura (together forming the taxon Meiura) respectively. Both species share similar coastal marine habitats and thus are confronted with similar environmental conditions. This study sets out to explore variations of general brain architecture of species that live in seemingly similar habitats but belong to different major malacostracan taxa and to understand possible differences of sensory systems and related brain compartments. We examined the brains of Carcinus maenas, Pagurus bernhardus, and three other hermit crab species with immunohistochemistry against tyrosinated tubulin, f-actin, synaptic proteins, RF-amides and allatostatin. Our comparison showed that their optic neuropils within the eyestalks display strong resemblance in gross morphology as well as in detailed organization, suggesting a rather similar potential of processing visual input. Besides the well-developed visual system, the olfactory neuropils are distinct components in the brain of both C. maenas and P. bernhardus as well as the other hermit crabs, suggesting that close integration of olfactory and visual information may be useful in turbid marine environments with low visibility, as is typical for many habitats such as, e.g., the Baltic and the North Sea. Comparing the shape of the olfactory glomeruli in the anomurans showed some variations, ranging from a wedge shape to an elongate morphology. Furthermore, the tritocerebrum and the organization of the second antennae associated with the tritocerebrum seem to differ markedly in C. maenas and P. bernhardus, indicating better mechanosensory abilities in the latter close to those of other Decapoda with long second antennae, such as Astacida, Homarida, or Achelata. This aspect may also represent an adaptation to the "hermit lifestyle" in which competition for shells is a major aspect of their life history. The shore

  17. Comparative brain architecture of the European shore crab Carcinus maenas (Brachyura) and the common hermit crab Pagurus bernhardus (Anomura) with notes on other marine hermit crabs.

    PubMed

    Krieger, Jakob; Sombke, Andy; Seefluth, Florian; Kenning, Matthes; Hansson, Bill S; Harzsch, Steffen

    2012-04-01

    The European shore crab Carcinus maenas and the common hermit crab Pagurus bernhardus are members of the sister taxa Brachyura and Anomura (together forming the taxon Meiura) respectively. Both species share similar coastal marine habitats and thus are confronted with similar environmental conditions. This study sets out to explore variations of general brain architecture of species that live in seemingly similar habitats but belong to different major malacostracan taxa and to understand possible differences of sensory systems and related brain compartments. We examined the brains of Carcinus maenas, Pagurus bernhardus, and three other hermit crab species with immunohistochemistry against tyrosinated tubulin, f-actin, synaptic proteins, RF-amides and allatostatin. Our comparison showed that their optic neuropils within the eyestalks display strong resemblance in gross morphology as well as in detailed organization, suggesting a rather similar potential of processing visual input. Besides the well-developed visual system, the olfactory neuropils are distinct components in the brain of both C. maenas and P. bernhardus as well as the other hermit crabs, suggesting that close integration of olfactory and visual information may be useful in turbid marine environments with low visibility, as is typical for many habitats such as, e.g., the Baltic and the North Sea. Comparing the shape of the olfactory glomeruli in the anomurans showed some variations, ranging from a wedge shape to an elongate morphology. Furthermore, the tritocerebrum and the organization of the second antennae associated with the tritocerebrum seem to differ markedly in C. maenas and P. bernhardus, indicating better mechanosensory abilities in the latter close to those of other Decapoda with long second antennae, such as Astacida, Homarida, or Achelata. This aspect may also represent an adaptation to the "hermit lifestyle" in which competition for shells is a major aspect of their life history. The shore

  18. Fatty Acids of Densely Packed Embryos of Carcinus maenas Reveal Homogeneous Maternal Provisioning and No Within-Brood Variation at Hatching.

    PubMed

    Rey, Felisa; Moreira, Ana S P; Ricardo, Fernando; Coimbra, Manuel A; Domingues, M Rosário M; Domingues, Pedro; Rosa, Rui; Queiroga, Henrique; Calado, Ricardo

    2016-04-01

    Embryonic development of decapod crustaceans relies on yolk reserves supplied to offspring through maternal provisioning. Unequal partitioning of nutritional reserves during oogenesis, as well as fluctuating environmental conditions during incubation, can be sources of within-brood variability. Ultimately, this potential variability may promote the occurrence of newly hatched larvae with differing yolk reserves and an unequal ability to endure starvation and/or suboptimal feeding during their early pelagic life. The present study evaluated maternal provisioning by analyzing fatty acid (FA) profiles in newly extruded embryos of Carcinus maenas Also assessed were the dynamics of such provisioning during embryogenesis, such as embryo location within the regions of the brooding chamber (left external, left internal, right external, and right internal). The FA profiles surveyed revealed a uniform transfer of maternal reserves from the female to the entire mass of embryos, and homogeneous embryonic development within the brooding chamber. Although C. maenas produces a densely packed mass of embryos that are unevenly distributed within its brooding chamber, this factor is not a source of within-brood variability during incubation. This finding contrasts with data already recorded for larger-sized brachyuran crabs, and suggests that the maternal behavior of C. maenas promotes homogeneous lipid catabolism during embryogenesis. PMID:27132134

  19. Monitoring PAH contamination in the field (South west Iberian Peninsula): biomonitoring using fluorescence spectrophotometry and physiological assessments in the shore crab Carcinus maenas (L.) (Crustacea: Decapoda).

    PubMed

    Dissanayake, Awantha; Bamber, Shaw D

    2010-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants of the marine environment, arising predominantly from petrochemical contamination and pyrogenic sources. A biomarker of PAH exposure was employed in a field study (South West, Spain) in both captured (indigenous) and deployed (caged) shore crabs (Carcinus maenas) in the chronic PAH-exposed Bays of Algeciras and Gibraltar (from associated harbour and boating activity) compared to a relatively 'clean' site (Cadiz). Metabolite fluorescence was attributed to the following key priority PAH groups; naphthalenes (NAPs), pyrenes (PYRs) and benzo[a]pyrenes (BAPs). Temporal variability was assessed using deployed populations over an eight week period. Petrogenic and pyrogenic PAH contamination (as an indicator of the PAH type) was demonstrated using a ratio between FF(BAP + PYR)/FF(NAP). Physiological assessments from deployed crabs demonstrated both physiological and cellular alterations as shown by reduced heart rates (at rest) and increased cellular stress in crabs from the PAH contaminated sites.

  20. The role of an ancestral hyperpolarization-activated cyclic nucleotide-gated K+ channel in branchial acid-base regulation in the green crab, Carcinus maenas.

    PubMed

    Fehsenfeld, Sandra; Weihrauch, Dirk

    2016-03-01

    Numerous electrophysiological studies on branchial K(+) transport in brachyuran crabs have established an important role for potassium channels in osmoregulatory ion uptake and ammonia excretion in the gill epithelium of decapod crustaceans. However, hardly anything is known of the actual nature of these channels in crustaceans. In the present study, the identification of a hyperpolarization-activated cyclic nucleotide-gated potassium channel (HCN) in the transcriptome of the green crab Carcinus maenas and subsequent performance of quantitative real-time PCR revealed the ubiquitous expression of this channel in this species. Even though mRNA expression levels in the cerebral ganglion were found to be approximately 10 times higher compared with all other tissues, posterior gills still expressed significant levels of HCN, indicating an important role for this transporter in branchial ion regulation. The relatively unspecific K(+)-channel inhibitor Ba(2+), as well as the HCN-specific blocker ZD7288, as applied in gill perfusion experiments and electrophysiological studies employing the split gill lamellae revealed the presence of at least two different K(+)/NH4(+)-transporting structures in the branchial epithelium of C. maenas. Furthermore, HCN mRNA levels in posterior gill 7 decreased significantly in response to the respiratory or metabolic acidosis that was induced by acclimation of green crabs to high environmental PCO2 and ammonia, respectively. Consequently, the present study provides first evidence that HCN-promoted NH4(+) epithelial transport is involved in both branchial acid-base and ammonia regulation in an invertebrate. PMID:26787479

  1. Reconciling deep calibration and demographic history: bayesian inference of post glacial colonization patterns in Carcinus aestuarii (Nardo, 1847) and C. maenas (Linnaeus, 1758).

    PubMed

    Marino, Ilaria A M; Pujolar, Jose Martin; Zane, Lorenzo

    2011-01-01

    A precise inference of past demographic histories including dating of demographic events using bayesian methods can only be achieved with the use of appropriate molecular rates and evolutionary models. Using a set of 596 mitochondrial cytochrome c oxidase I (COI) sequences of two sister species of European green crabs of the genus Carcinus (C. maenas and C. aestuarii), our study shows how chronologies of past evolutionary events change significantly with the application of revised molecular rates that incorporate biogeographic events for calibration and appropriate demographic priors. A clear signal of demographic expansion was found for both species, dated between 10,000 and 20,000 years ago, which places the expansions events in a time frame following the Last Glacial Maximum (LGM). In the case of C. aestuarii, a population expansion was only inferred for the Adriatic-Ionian, suggestive of a colonization event following the flooding of the Adriatic Sea (18,000 years ago). For C. maenas, the demographic expansion inferred for the continental populations of West and North Europe might result from a northward recolonization from a southern refugium when the ice sheet retreated after the LGM. Collectively, our results highlight the importance of using adequate calibrations and demographic priors in order to avoid considerable overestimates of evolutionary time scales. PMID:22164307

  2. Reconciling Deep Calibration and Demographic History: Bayesian Inference of Post Glacial Colonization Patterns in Carcinus aestuarii (Nardo, 1847) and C. maenas (Linnaeus, 1758)

    PubMed Central

    Marino, Ilaria A. M.; Pujolar, Jose Martin; Zane, Lorenzo

    2011-01-01

    A precise inference of past demographic histories including dating of demographic events using Bayesian methods can only be achieved with the use of appropriate molecular rates and evolutionary models. Using a set of 596 mitochondrial cytochrome c oxidase I (COI) sequences of two sister species of European green crabs of the genus Carcinus (C. maenas and C. aestuarii), our study shows how chronologies of past evolutionary events change significantly with the application of revised molecular rates that incorporate biogeographic events for calibration and appropriate demographic priors. A clear signal of demographic expansion was found for both species, dated between 10,000 and 20,000 years ago, which places the expansions events in a time frame following the Last Glacial Maximum (LGM). In the case of C. aestuarii, a population expansion was only inferred for the Adriatic-Ionian, suggestive of a colonization event following the flooding of the Adriatic Sea (18,000 years ago). For C. maenas, the demographic expansion inferred for the continental populations of West and North Europe might result from a northward recolonization from a southern refugium when the ice sheet retreated after the LGM. Collectively, our results highlight the importance of using adequate calibrations and demographic priors in order to avoid considerable overestimates of evolutionary time scales. PMID:22164307

  3. Spontaneous alternation and locomotor activity in three species of marine crabs: green crab (Carcinus maenas), blue crab (Callinectes sapidus), and fiddler crab (Uca pugnax).

    PubMed

    Balcı, Fuat; Ramey-Balcı, Patricia A; Ruamps, Perrine

    2014-02-01

    Spontaneous alternation refers to the tendency of organisms to explore places that they have least recently visited. Our previous work showed that alternation performance of Carcinus maenas (invasive European green crab) was significantly higher than Callinectes sapidus (native blue crab), and chance level performance (Ramey, P. A., Teichman, E., Oleksiak, J., & Balcı, F. [2009]. Spontaneous alternation in marine crabs: Invasive versus native species. Behavioural Processes, 82, 51-55.). In the current study, we first tested the robustness of these findings in the absence of visual cues, longer test durations, and wider maze dimensions. These manipulations enabled us to determine whether these two crab species relied on the visual cues provided during the spontaneous alternation task in our prior work, and allowed for better characterization of their exploratory activity in the maze. Our original findings were reproduced in the present study under these new task conditions, suggesting no role for visual cues during alternation, and emphasizing the robustness and generalizability of the corresponding interspecies differences in alternation performance. We also tested whether the lower alternation performance of C. sapidus also applied to another native crab species, Uca pugnax (fiddler crab). Spontaneous alternation performance of U. pugnax was significantly lower than C. maenas but indistinguishable from C. sapidus. Finally, we examined whether the potentially higher inherent risk-sensitivity of C. sapidus could have contributed to their lower alternation performance by testing C. maenas in the presence of a larger natural predator (stressor). Higher risk sensitivity presumably induced by the stressor led to locomotor activity patterns that better resembled those of C. sapidus, however the resultant reduction in alternation performance was not statistically significant. PMID:24060243

  4. Spontaneous alternation and locomotor activity in three species of marine crabs: green crab (Carcinus maenas), blue crab (Callinectes sapidus), and fiddler crab (Uca pugnax).

    PubMed

    Balcı, Fuat; Ramey-Balcı, Patricia A; Ruamps, Perrine

    2014-02-01

    Spontaneous alternation refers to the tendency of organisms to explore places that they have least recently visited. Our previous work showed that alternation performance of Carcinus maenas (invasive European green crab) was significantly higher than Callinectes sapidus (native blue crab), and chance level performance (Ramey, P. A., Teichman, E., Oleksiak, J., & Balcı, F. [2009]. Spontaneous alternation in marine crabs: Invasive versus native species. Behavioural Processes, 82, 51-55.). In the current study, we first tested the robustness of these findings in the absence of visual cues, longer test durations, and wider maze dimensions. These manipulations enabled us to determine whether these two crab species relied on the visual cues provided during the spontaneous alternation task in our prior work, and allowed for better characterization of their exploratory activity in the maze. Our original findings were reproduced in the present study under these new task conditions, suggesting no role for visual cues during alternation, and emphasizing the robustness and generalizability of the corresponding interspecies differences in alternation performance. We also tested whether the lower alternation performance of C. sapidus also applied to another native crab species, Uca pugnax (fiddler crab). Spontaneous alternation performance of U. pugnax was significantly lower than C. maenas but indistinguishable from C. sapidus. Finally, we examined whether the potentially higher inherent risk-sensitivity of C. sapidus could have contributed to their lower alternation performance by testing C. maenas in the presence of a larger natural predator (stressor). Higher risk sensitivity presumably induced by the stressor led to locomotor activity patterns that better resembled those of C. sapidus, however the resultant reduction in alternation performance was not statistically significant.

  5. Application of neutral red retention assay to caged clams (Ruditapes decussatus) and crabs (Carcinus maenas) in the assessment of dredged material.

    PubMed

    Buratti, Sara; Ramos-Gómez, Julia; Fabbri, Elena; DelValls, T Angel; Martín-Díaz, M Laura

    2012-01-01

    Dredged material management is a key issue for the protection of aquatic environments. The in situ approach using caged bioindicator species has been chosen lately as a new methodology for the assessment of dredged material. In a tier testing approach, neutral red retention (NRR) assay has been applied as a screening tool to detect adverse changes in health status associated with contamination. Nevertheless, to authors' knowledge, little is known about the application and validation of this technique in sediment bioindicator species and under field conditions. Caged Ruditapes decussatus and Carcinus maenas were exposed during 28 days to potentially contaminated sediments at three sites in Algeciras Bay (SW Spain) and one site in Cádiz Bay (SW Spain). Lysosomal membrane stability was measured over time in haemolymph samples of exposed clams and crabs using the NRR assay. Sediment characterization of the study sites was performed in parallel. NRR time did not vary significantly (p > 0.05) over time in organisms from Cádiz Bay. Conversely, significant differences (p < 0.05) in NRR time were found in clams and crabs exposed to sediments from Algeciras Bay, which exhibited a 30-70% decrease in haemocyte lysosome membrane stability compared to day 0. Statistical analysis showed a strong correlation between the drop of haemocyte lysosome membrane stability, in both crabs and clams, and the presence of metals (p < 0.05) and PAHs (p < 0.01) in the studied sediments. The results obtained confirmed the use of NRR assay as a suitable and sensitive method to be used in the assessment of sediment quality using as bioindicator species the clam R. philippinarum and the crab C. maenas. PMID:21870173

  6. Seasonal fluctuations of tissue mercury contents in the European shore crab Carcinus maenas from low and high contamination areas (Ria de Aveiro, Portugal).

    PubMed

    Pereira, E; Abreu, S N; Coelho, J P; Lopes, C B; Pardal, M A; Vale, C; Duarte, A C

    2006-11-01

    The main objective was to study the seasonal variation of mercury concentrations in different tissues (muscle, hepatopancreas and gills) of Carcinus maenas from low and high Hg contaminated areas, a valuable resource in temperate estuaries and a possible pathway for human uptake. Individuals of two size classes (around 35 and 55 mm cephalothorax wide) were captured monthly between March 1999 and May 2000 in two areas of Ria de Aveiro: in the main navigation channel that connects the lagoon to the sea, and in the inner lagoon area heavily contaminated by mercury (maximum Hg in sediments of 5.4 microg g(-1)). Pronounced decreases in salinity and temperature and reduced food availability in winter seemed to be the responsible for the decline of the crab condition index (0.75-0.45) in larger individuals. Muscle and hepatopancreas exhibited higher mercury concentrations than gills, with concentrations in the contaminated site ranging from 0.03 to 0.63 microg g(-1) and 0.02 to 0.34 microg g(-1), respectively. Linear regressions between muscle and hepatopancreas (r=0.94, p<0.001) and muscle and gills (r=0.97, p<0.001) suggested a rapid redistribution of mercury inside the organism. During winter, a rapid elimination of mercury was found in the three analysed tissues followed by uptake. Larger crabs presented elimination rates from 18 to 34 ng g(-1) per week, while the smaller crabs showed lower elimination rates (10-24 ng g(-1) per week). The uptake was similar in both size classes (11-15 ng g(-1) and 8.1-15 ng g(-1) per week, respectively for large and small crabs). Our results suggest that C. maenas harvested in the contaminated areas must be considered with caution, since Hg concentrations were found to exceed the threshold concentration allowed for human consumption (0.5 microg g(-1)). PMID:16824552

  7. Effects of an Offshore Wind Farm (OWF) on the Common Shore Crab Carcinus maenas: Tagging Pilot Experiments in the Lillgrund Offshore Wind Farm (Sweden)

    PubMed Central

    Langhamer, Olivia; Holand, Håkon; Rosenqvist, Gunilla

    2016-01-01

    Worldwide growth of offshore renewable energy production will provide marine organisms with new hard substrate for colonization in terms of artificial reefs. The artificial reef effect is important when planning offshore installations since it can create habitat enhancement. Wind power is the most advanced technology within offshore renewable energy sources and there is an urgent need to study its impacts on the marine environment. To test the hypothesis that offshore wind power increases the abundance of reef species relative to a reference area, we conduct an experiment on the model species common shore crab (Carcinus maenas).Overall, 3962 crabs were captured, observed, marked and released in 2011 and 1995 crabs in 2012. Additionally, carapace size, sex distribution, color morphs and body condition was recorded from captured crabs. We observed very low recapture rates at all sites during both years which made evaluating differences in population sizes very difficult. However, we were able to estimate population densities from the capture record for all three sites. There was no obvious artificial reef effect in the Lillgrund wind farm, but a spill-over effect to nearby habitats cannot be excluded. We could not find any effect of the wind farm on either, morphs, sex distribution or condition of the common shore crab. Our study found no evidence that Lillgrund wind farm has a negative effect on populations of the common shore crab. This study provides the first quantitative and experimental data on the common shore crab in relation to offshore wind farms. PMID:27780212

  8. Adaptive considerations of temperature dependence of neuromuscular function in two species of summer- and winter-caught Crab (Carcinus maenas and Cancer pagurus).

    PubMed

    Hyde, D; Pearson, T; Qari, S; Bowler, K

    2015-08-01

    The aim of this study was to determine seasonal differences in the temperature dependence of neuromuscular parameters of the dactylopodite walking leg closer muscle in two species of freshly caught summer and winter decapod crabs. The relatively stenothermal Cancer pagurus (Cp) and eurythermal Carcinus maenas (Cm) muscle resting potential (RP) hyperpolarised significantly with increasing experimental temperature. The muscle RP in Cm was seasonally dependent at acute temperatures above 20 °C whereas in Cp no seasonal effect was observed. The latent period of the muscle excitatory junction potential (EJP) following tonic motor nerve stimulation was significantly longer in winter-caught crabs in both species, although the effect was significantly more marked in Cp than Cm. Summer-caught Cp had larger excitatory junction potentials (EJPs) than did winter-caught crabs, a seasonal effect not seen in Cm. In contrast, marked seasonal differences were found in the EJP decay time constant in Cm having significantly longer time constants in winter-caught crabs, where no seasonal difference was found in Cp. These results suggest that different seasonal effects of neuromuscular parameters between Cm and Cp may reflect different strategies of response to their different seasonal temperature environments. PMID:25994492

  9. The competitive and predatory impacts of the nonindigenous crab Carcinus maenas (L.) on early benthic phase Dungeness crab Cancer magister Dana.

    PubMed

    McDonald, P S.; Jensen, G C.; Armstrong, D A.

    2001-03-30

    We evaluate the potential competitive and predatory impacts of nonindigenous European green crab Carcinus maenas on native Dungeness crab Cancer magister in the northeast Pacific. The coastal estuaries of Washington State, USA, provide appropriate habitat for recently introduced green crab, yet these areas are important nursery grounds for Dungeness crab and contribute greatly to the coastal crab fishery. Juvenile Dungeness crabs are dependent on limited intertidal epibenthic shell for refuge habitat during early benthic life and experience increased mortality on open sand and mud as a result of predation by fish and birds. Early juveniles throughout the subtidal are similarly at risk due to predation by fish and especially adult conspecifics. Laboratory experiments and infrared video observations revealed that juvenile green crab displace Dungeness crab of equal size from shelters during one-on-one competition. Green crab also consistently win nocturnal foraging trials in which the species compete for fresh, damaged clams. Field and laboratory enclosure experiments show that juvenile Dungeness crab emigrate from oyster shell habitat as a result of competition and predation by adult green crab. Depending on the extent to which the two species overlap, interactions with the dominant nonindigenous species could have a negative influence on juvenile Dungeness crab survival and could conceivably impact recruitment to the fishery. However, current evidence indicates that the distribution of green crab in Washington State is far removed from nursery areas of Dungeness crab. PMID:11239624

  10. Differential acid-base regulation in various gills of the green crab Carcinus maenas: Effects of elevated environmental pCO2.

    PubMed

    Fehsenfeld, Sandra; Weihrauch, Dirk

    2013-01-01

    Euryhaline decapod crustaceans possess an efficient regulation apparatus located in the gill epithelia, providing a high adaptation potential to varying environmental abiotic conditions. Even though many studies focussed on the osmoregulatory capacity of the gills, acid-base regulatory mechanisms have obtained much less attention. In the present study, underlying principles and effects of elevated pCO(2) on acid-base regulatory patterns were investigated in the green crab Carcinus maenas acclimated to diluted seawater. In gill perfusion experiments, all investigated gills 4-9 were observed to up-regulate the pH of the hemolymph by 0.1-0.2 units. Anterior gills, especially gill 4, were identified to be most efficient in the equivalent proton excretion rate. Ammonia excretion rates mirrored this pattern among gills, indicating a linkage between both processes. In specimen exposed to elevated pCO(2) levels for at least 7 days, mimicking a future ocean scenario as predicted until the year 2300, hemolymph K(+) and ammonia concentrations were significantly elevated, and an increased ammonia excretion rate was observed. A detailed quantitative gene expression analysis revealed that upon elevated pCO(2) exposure, mRNA levels of transcripts hypothesized to be involved in ammonia and acid-base regulation (Rhesus-like protein, membrane-bound carbonic anhydrase, Na(+)/K(+)-ATPase) were affected predominantly in the non-osmoregulating anterior gills. PMID:23022520

  11. Interspecific hybridization and mitochondrial introgression in invasive carcinus shore crabs.

    PubMed

    Darling, John A

    2011-01-01

    Interspecific hybridization plays an important role in facilitating adaptive evolutionary change. More specifically, recent studies have demonstrated that hybridization may dramatically influence the establishment, spread, and impact of invasive populations. In Japan, previous genetic evidence for the presence of two non-native congeners, the European green crab Carcinus maenas and the Mediterranean green crab C. aestuarii, has raised questions regarding the possibility of hybridization between these sister species. Here I present analysis based on both nuclear microsatellites and the mitochondrial cytochrome C oxidase subunit I (COI) gene which unambiguously argues for a hybrid origin of Japanese Carcinus. Despite the presence of mitochondrial lineages derived from both C. maenas and C. aestuarii, the Japanese population is panmictic at nuclear loci and has achieved cytonuclear equilibrium throughout the sampled range in Japan. Furthermore, analysis of admixture at nuclear loci indicates dramatic introgression of the C. maenas mitochondrial genome into a predominantly C. aestuarii nuclear background. These patterns, along with inferences drawn from the observational record, argue for a hybridization event pre-dating the arrival of Carcinus in Japan. The clarification of both invasion history and evolutionary history afforded by genetic analysis provides information that may be critically important to future studies aimed at assessing risks posed by invasive Carcinus populations to Japan and the surrounding region. PMID:21423759

  12. Molt regulation in green and red color morphs of the crab Carcinus maenas: gene expression of molt-inhibiting hormone signaling components.

    PubMed

    Abuhagr, Ali M; Blindert, Jennifer L; Nimitkul, Sukkrit; Zander, Ian A; Labere, Stefan M; Chang, Sharon A; Maclea, Kyle S; Chang, Ernest S; Mykles, Donald L

    2014-03-01

    In decapod crustaceans, regulation of molting is controlled by the X-organ/sinus gland complex in the eyestalks. The complex secretes molt-inhibiting hormone (MIH), which suppresses production of ecdysteroids by the Y-organ (YO). MIH signaling involves nitric oxide and cGMP in the YO, which expresses nitric oxide synthase (NOS) and NO-sensitive guanylyl cyclase (GC-I). Molting can generally be induced by eyestalk ablation (ESA), which removes the primary source of MIH, or by multiple leg autotomy (MLA). In our work on Carcinus maenas, however, ESA has limited effects on hemolymph ecdysteroid titers and animals remain in intermolt at 7 days post-ESA, suggesting that adults are refractory to molt induction techniques. Consequently, the effects of ESA and MLA on molting and YO gene expression in C. maenas green and red color morphotypes were determined at intermediate (16 and 24 days) and long-term (~90 days) intervals. In intermediate-interval experiments, ESA of intermolt animals caused transient twofold to fourfold increases in hemolymph ecdysteroid titers during the first 2 weeks. In intermolt animals, long-term ESA increased hemolymph ecdysteroid titers fourfold to fivefold by 28 days post treatment, but there was no late premolt peak (>400 pg μl(-1)) characteristic of late premolt animals and animals did not molt by 90 days post-ESA. There was no effect of ESA or MLA on the expression of Cm-elongation factor 2 (EF2), Cm-NOS, the beta subunit of GC-I (Cm-GC-Iβ), a membrane receptor GC (Cm-GC-II) and a soluble NO-insensitive GC (Cm-GC-III) in green morphs. Red morphs were affected by prolonged ESA and MLA treatments, as indicated by large decreases in Cm-EF2, Cm-GC-II and Cm-GC-III mRNA levels. ESA accelerated the transition of green morphs to the red phenotype in intermolt animals. ESA delayed molting in premolt green morphs, whereas intact and MLA animals molted by 30 days post treatment. There were significant effects on YO gene expression in intact animals

  13. Sites of release of Putative Sex Pheromone and Sexual Behaviour in Female Carcinus maenas(Crustacea: Decapoda)

    NASA Astrophysics Data System (ADS)

    Bamber, S. D.; Naylor, E.

    1997-02-01

    Pre-moult female Carcinus maenasurine was confirmed as a source of putative sex pheromone. The sexual and temporal specificity of bioactivity in pre-moult female urine was demonstrated when urine samples taken from inter-moult and pre-moult male crabs, and inter-moult females, failed to generate a sexual response from receptive males. Detection sensitivity of male crabs to pre-moult female urine was established at a dilution factor of 1 μl of urine in 10 ml of seawater. Experimental blockage of the site of urine release (the antennal gland opercula) failed to diminish the chemical attractiveness of pre-moult female crabs to test males, implicating at least one further site of putative pheromone release. Observations of female sexual behaviour demonstrated an active role by pre-moult and post-moult female crabs when introduced to male crabs whose locomotor movement had been temporarily restricted.

  14. Master of all trades: thermal acclimation and adaptation of cardiac function in a broadly distributed marine invasive species, the European green crab, Carcinus maenas.

    PubMed

    Tepolt, Carolyn K; Somero, George N

    2014-04-01

    As global warming accelerates, there is increasing concern about how ecosystems may change as a result of species loss and replacement. Here, we examined the thermal physiology of the European green crab (Carcinus maenas Linnaeus 1758), a globally invasive species, along three parallel thermal gradients in its native and invasive ranges. At each site, we assessed cardiac physiology to determine heat and cold tolerance and acclimatory plasticity. We found that, overall, the species is highly tolerant of both heat and cold, and that it survives higher temperatures than co-occurring native marine crustaceans. Further, we found that both heat and cold tolerance are plastic in response to short-term acclimation (18-31 days at either 5 or 25°C). Comparing patterns within ranges, we found latitudinal gradients in thermal tolerance in the native European range and in the invasive range in eastern North America. This pattern is strongest in the native range, and likely evolved there. Because of a complicated invasion history, the latitudinal pattern in the eastern North American invasive range may be due either to rapid adaptation post-invasion or to adaptive differences between the ancestral populations that founded the invasion. Overall, the broad thermal tolerance ranges of green crabs, which may facilitate invasion of novel habitats, derive from high inherent eurythermality and acclimatory plasticity and potentially adaptive differentiation among populations. The highly flexible physiology that results from these capacities may represent the hallmark of a successful invasive species, and may provide a model for success in a changing world.

  15. Making sense of nickel accumulation and sub-lethal toxic effects in saline waters: Fate and effects of nickel in the green crab, Carcinus maenas.

    PubMed

    Blewett, Tamzin A; Glover, Chris N; Fehsenfeld, Sandra; Lawrence, Michael J; Niyogi, Som; Goss, Greg G; Wood, Chris M

    2015-07-01

    In freshwater, invertebrates nickel (Ni) is considered an ionoregulatory toxicant, but its mechanism of toxicity in marine settings, and how this varies with salinity, is poorly understood. This study investigated Ni accumulation and physiological mechanisms of sub-lethal Ni toxicity in the euryhaline green crab Carcinus maenas. Male crabs were exposed to 8.2μg/L (the US EPA chronic criterion concentration for salt waters) of waterborne Ni (radiolabelled with (63)Ni) at three different salinities, 20%, 60% and 100% SW for 24h. Whole body Ni accumulation in 20% SW was 3-5 fold greater than in 60% or 100% SW, and >80% of accumulated Ni was in the carapace at all salinities. Ni also accumulated in posterior gill 8, which showed a higher accumulation in 20% SW than in other salinities, a pattern also seen at higher exposure concentrations of Ni (500 and 3000μg/L). Gill perfusion experiments revealed that Ni was taken up by both anterior and posterior gills, but in 20% SW the posterior gill 8, which performs ionoregulatory functions, accumulated more Ni than the anterior gill 5, which primarily has a respiratory function. The sub-lethal consequences of Ni exposure were investigated by placing crabs in Ni concentrations of 8.2, 500, and 3000μg/L at 20, 60 or 100% SW for 24h. In 20% SW, haemolymph Ca levels were significantly decreased by exposure to Ni concentrations of 8.2μg/L or higher, whereas Na concentrations were depressed only at 3000μg/L. Na(+)/K(+)-ATPase activity was inhibited at both 500 and 3000μg/L in gill 8, but only in 20% SW. Haemolymph K, Mg, and osmolality were unaffected throughout, though all varied with salinity in the expected fashion. These data suggest that Ni impacts ionoregulatory function in the green crab, in a gill- and salinity-dependent manner. PMID:25914092

  16. Longitudinal distribution and lateral pattern of megalopal settlement and juvenile recruitment of Carcinus maenas (L.) (Brachyura, Portunidae) in the Mira River Estuary, Portugal

    NASA Astrophysics Data System (ADS)

    Silva, Inês C.; Dinis, Ana M.; Francisco, Sara M.; Flores, Augusto A. V.; Paula, José

    2006-08-01

    Settlement is a critical process in the life history of crabs, and thus affecting the abundance, distribution and structure of estuarine communities. The spatial pattern of settlement of megalopae of the shore crab Carcinus maenas along a longitudinal estuarine gradient (Mira River Estuary, Portugal) was examined, as well as its effects on the juvenile population. To measure megalopal settlement, four replicate collectors were deployed in six equally spaced stations along the estuarine axis. Juveniles were collected on the same locations with a quadrat randomly deployed on the substrate. To assess fine-scale megalopal settlement within a curved region of the estuary, replicate collectors were deployed on both margins along Moinho da Asneira curve. Megalopae settled differently along the six longitudinal points, with a tendency to attenuate their settlement upstream. Within the curved region, megalopae preferentially settled on the left margin collectors, probably due to the weaker velocity speeds felt on this margin. Concerning the overall juvenile density, there were significant differences among the stations distributed along the estuary, but they did no reflect a longitudinal dispersion attenuation pattern. Size-frequency distribution of the juvenile population showed that the average size is higher on the left margin. Recruits (carapace length between 1.0 mm and 3.4 mm) were more abundant on the upstream stations. Density of early juveniles (3.4 mm-6.5 mm) and juveniles (6.5 mm-10 mm) was more stable throughout the estuary axis than that of recruits. This distribution pattern may result from tidal excursion processes or mechanisms to avoid biotic interactions, such as predation and competition.

  17. Elevated seawater levels of CO(2) change the metabolic fingerprint of tissues and hemolymph from the green shore crab Carcinus maenas.

    PubMed

    Hammer, Karen M; Pedersen, Sindre A; Størseth, Trond R

    2012-09-01

    Carbon dioxide (CO(2)) acts as a weak acid in water and the increasing level of CO(2) in the atmosphere leads to ocean acidification. In addition, possible leakage from sub-seabed storage of anthropogenic CO(2) may pose a threat to the marine environment. (1)H NMR spectroscopy was applied to extracts of hemolymph, gills and leg muscle from shore crabs (Carcinus maenas) to examine the metabolic response to elevated levels of CO(2). Crabs were exposed to different levels of CO(2)-acidified seawater with pH(NBS) 7.4, 6.6 and 6.3 (pCO(2)~2600, 16,000 and 30,000 μatm, respectively) for two weeks (level-dependent exposure). In addition, the metabolic response was followed for up to 4 weeks of exposure to seawater pH(NBS) 6.9 (pCO(2)~7600 μatm). Partial least squares regression analysis of data showed an increased differentiation between metabolic fingerprints of controls and exposed groups for all sample types with increasing CO(2) levels. Difference between controls and animals subjected to time-dependent exposure appeared after 4 weeks in the hemolymph and gills, and after 48 h of exposure in the leg muscle. Changes in metabolic profiles were mainly due to a reduced level of important intracellular osmolytes such as amino acids (glycine, proline), while the level of other metabolites varied between the different sample types. The results are similar to what is observed in animals exposed to hypo-osmotic stress and may suggest disturbances in intracellular iso-osmotic regulation. The results may also reflect increased catabolism of amino acids to supply the body fluids with proton-buffering ammonia (NH(3)). Alternatively, the findings may reflect an exhaustive effect of CO(2) exposure. PMID:22763285

  18. Master of all trades: thermal acclimation and adaptation of cardiac function in a broadly distributed marine invasive species, the European green crab, Carcinus maenas.

    PubMed

    Tepolt, Carolyn K; Somero, George N

    2014-04-01

    As global warming accelerates, there is increasing concern about how ecosystems may change as a result of species loss and replacement. Here, we examined the thermal physiology of the European green crab (Carcinus maenas Linnaeus 1758), a globally invasive species, along three parallel thermal gradients in its native and invasive ranges. At each site, we assessed cardiac physiology to determine heat and cold tolerance and acclimatory plasticity. We found that, overall, the species is highly tolerant of both heat and cold, and that it survives higher temperatures than co-occurring native marine crustaceans. Further, we found that both heat and cold tolerance are plastic in response to short-term acclimation (18-31 days at either 5 or 25°C). Comparing patterns within ranges, we found latitudinal gradients in thermal tolerance in the native European range and in the invasive range in eastern North America. This pattern is strongest in the native range, and likely evolved there. Because of a complicated invasion history, the latitudinal pattern in the eastern North American invasive range may be due either to rapid adaptation post-invasion or to adaptive differences between the ancestral populations that founded the invasion. Overall, the broad thermal tolerance ranges of green crabs, which may facilitate invasion of novel habitats, derive from high inherent eurythermality and acclimatory plasticity and potentially adaptive differentiation among populations. The highly flexible physiology that results from these capacities may represent the hallmark of a successful invasive species, and may provide a model for success in a changing world. PMID:24671964

  19. Neuroendocrine disruption in the shore crab Carcinus maenas: Effects of serotonin and fluoxetine on chh- and mih-gene expression, glycaemia and ecdysteroid levels.

    PubMed

    Robert, Alexandrine; Monsinjon, Tiphaine; Delbecque, Jean-Paul; Olivier, Stéphanie; Poret, Agnès; Foll, Frank Le; Durand, Fabrice; Knigge, Thomas

    2016-06-01

    Serotonin, a highly conserved neurotransmitter, controls many biological functions in vertebrates, but also in invertebrates. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are commonly used in human medication to ease depression by affecting serotonin levels. Their residues and metabolites can be detected in the aquatic environment and its biota. They may also alter serotonin levels in aquatic invertebrates, thereby perturbing physiological functions. To investigate whether such perturbations can indeed be expected, shore crabs (Carcinus maenas) were injected either with serotonin, fluoxetine or a combination of both. Dose-dependent effects of fluoxetine ranging from 250 to 750nM were investigated. Gene expression of crustacean hyperglycemic hormone (chh) as well as moult inhibiting hormone (mih) was assessed by RT-qPCR at 2h and 12h after injection. Glucose and ecdysteroid levels in the haemolymph were monitored in regular intervals until 12h. Serotonin led to a rapid increase of chh and mih expression. On the contrary, fluoxetine only affected chh and mih expression after several hours, but kept expression levels significantly elevated. Correspondingly, serotonin rapidly increased glycaemia, which returned to normal or below normal levels after 12h. Fluoxetine, however, resulted in a persistent low-level increase of glycaemia, notably during the period when negative feedback regulation reduced glycaemia in the serotonin treated animals. Ecdysteroid levels were significantly decreased by serotonin and fluoxetine, with the latter showing less pronounced and less rapid, but longer lasting effects. Impacts of fluoxetine on glycaemia and ecdysteroids were mostly observed at higher doses (500 and 750nM) and affected principally the response dynamics, but not the amplitude of glycaemia and ecdysteroid-levels. These results suggest that psychoactive drugs are able to disrupt neuroendocrine control in decapod crustaceans, as they interfere with the

  20. Neuroendocrine disruption in the shore crab Carcinus maenas: Effects of serotonin and fluoxetine on chh- and mih-gene expression, glycaemia and ecdysteroid levels.

    PubMed

    Robert, Alexandrine; Monsinjon, Tiphaine; Delbecque, Jean-Paul; Olivier, Stéphanie; Poret, Agnès; Foll, Frank Le; Durand, Fabrice; Knigge, Thomas

    2016-06-01

    Serotonin, a highly conserved neurotransmitter, controls many biological functions in vertebrates, but also in invertebrates. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are commonly used in human medication to ease depression by affecting serotonin levels. Their residues and metabolites can be detected in the aquatic environment and its biota. They may also alter serotonin levels in aquatic invertebrates, thereby perturbing physiological functions. To investigate whether such perturbations can indeed be expected, shore crabs (Carcinus maenas) were injected either with serotonin, fluoxetine or a combination of both. Dose-dependent effects of fluoxetine ranging from 250 to 750nM were investigated. Gene expression of crustacean hyperglycemic hormone (chh) as well as moult inhibiting hormone (mih) was assessed by RT-qPCR at 2h and 12h after injection. Glucose and ecdysteroid levels in the haemolymph were monitored in regular intervals until 12h. Serotonin led to a rapid increase of chh and mih expression. On the contrary, fluoxetine only affected chh and mih expression after several hours, but kept expression levels significantly elevated. Correspondingly, serotonin rapidly increased glycaemia, which returned to normal or below normal levels after 12h. Fluoxetine, however, resulted in a persistent low-level increase of glycaemia, notably during the period when negative feedback regulation reduced glycaemia in the serotonin treated animals. Ecdysteroid levels were significantly decreased by serotonin and fluoxetine, with the latter showing less pronounced and less rapid, but longer lasting effects. Impacts of fluoxetine on glycaemia and ecdysteroids were mostly observed at higher doses (500 and 750nM) and affected principally the response dynamics, but not the amplitude of glycaemia and ecdysteroid-levels. These results suggest that psychoactive drugs are able to disrupt neuroendocrine control in decapod crustaceans, as they interfere with the

  1. Carapace Colour, Inter-moult Duration and the Behavioural and Physiological Ecology of the Shore Crab Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Reid, D. G.; Abelló, P.; Kaiser, M. J.; Warman, C. G.

    1997-02-01

    Adult male Carcinus maenasoccur on the shore with carapace colours ranging from green to deep red. In the past, this was believed to be indicative of moult state; green crabs having recently moulted and red ones being in late inter-moult. A series of different studies carried out in recent years has shown that this is not the full story. Green males have been shown to be more tolerant of salinity fluctuations and aerial exposure than red males. Conversely, red males compete more successfully for mates and food. It is hypothesized that some crabs remain in inter-moult longer than others, developing stronger and thicker carapaces and chelae, and are thus more likely to win mating conflicts. This advantage is gained at the cost of reduced tolerance to the conditions of intertidal life. The change in colouration is believed to be due to photo-denaturation of pigments in the carapace over a long inter-moult. This paper is a synthesis of studies which have led to these conclusions, and their importance is discussed in relation to the behavioural and physiological ecology of other intertidal Crustacea.

  2. Effects of salinity on short-term waterborne zinc uptake, accumulation and sub-lethal toxicity in the green shore crab (Carcinus maenas).

    PubMed

    Niyogi, Som; Blewett, Tamzin A; Gallagher, Trevor; Fehsenfeld, Sandra; Wood, Chris M

    2016-09-01

    Waterborne zinc (Zn) is known to cause toxicity to freshwater animals primarily by disrupting calcium (Ca) homeostasis during acute exposure, but its effects in marine and estuarine animals are not well characterized. The present study investigated the effects of salinity on short-term Zn accumulation and sub-lethal toxicity in the euryhaline green shore crab, Carcinus maenas. The kinetic and pharmacological properties of short-term branchial Zn uptake were also examined. Green crabs (n=10) were exposed to control (no added Zn) and 50μM (3.25mgL(-1)) of waterborne Zn (∼25% of 96h LC50 in 100 seawater) for 96h at 3 different salinity regimes (100%, 60% and 20% seawater). Exposure to waterborne Zn increased tissue-specific Zn accumulation across different salinities. However, the maximum accumulation occurred in 20% seawater and no difference was recorded between 60% and 100% seawater. Gills appeared to be the primary site of Zn accumulation, since the accumulation was significantly higher in the gills relative to the hepatopancreas, haemolymph and muscle. Waterborne Zn exposure induced a slight increase in haemolymph osmolality and chloride levels irrespective of salinity. In contrast, Zn exposure elicited marked increases in both haemolymph and gill Ca levels, and these changes were more pronounced in 20% seawater relative to that in 60% or 100% seawater. An in vitro gill perfusion technique was used to examine the characteristics of short-term (1-4h) branchial Zn uptake over an exposure concentration range of 3-12μM (200-800μgL(-1)). The rate of short-term branchial Zn uptake did not change significantly after 2h, and no difference was recorded in the rate of uptake between the anterior (respiratory) and posterior (ion transporting) gills. The in vitro branchial Zn uptake occurred in a concentration-dependent manner across different salinities. However, the rate of uptake was consistently higher in 20% seawater relative to 60% or 100% seawater - similar to

  3. Cadmium in the shore crab Carcinus maenas: seasonal variation in cadmium content and uptake and elimination of cadmium after administration via food.

    PubMed

    Bjerregaard, Poul; Bjørn, Lars; Nørum, Ulrik; Pedersen, Knud L

    2005-03-25

    The uptake and assimilation efficiency of cadmium administered via the food in the shore crab Carcinus maenas were investigated together with elimination kinetics and seasonal variations in cadmium content. The majority of shore crabs assimilated between 41 and 86% of the cadmium administered in their food. More than 90% of the cadmium taken up from food was retained in midgut gland. Elimination of cadmium after uptake from one meal of radioactively labelled soft parts of blue mussels could be described by a three-compartment model (percent 109Cd-retained = 64 x e(-0.001107 x t) + 25 x e(-0.0385 x t)+11 x e(-0.888 x t)). The biological half-life for cadmium in the most slowly exchanging compartment (containing 64% of the body burden) was 626 days. Groups of male and female shore crabs were collected from an uncontaminated site in the period May till October and the concentrations of cadmium in midgut gland and gills were determined. Male crabs had higher cadmium concentrations in the midgut gland in June and August (mean 2.7 microg Cd g(-1) dry weight) than they had in May, September and October (mean 1.7 microg Cd g(-1) dry weight). Females generally had slightly lower cadmium concentrations in the midgut gland than the males, except for a relatively high concentration in May. The cadmium concentrations in gills generally ranged between 0.3 and 0.5 microg Cd g(-1) dry weight) except for male values in October (mean 1 microg Cd g(-1) dry weight). Some of the seasonal changes in cadmium content of the crabs might plausibly be explained by changes in cadmium uptake from water, i.e. changes during the moult cycle and changes in cadmium uptake rates from water brought about by changes in ambient factors such as salinity and temperature. However, uptake of cadmium from water and transfer to the midgut gland take place at a rate that is two orders of magnitude too low to account for the increase in the cadmium concentrations in midgut gland in male crabs between May and

  4. Laboratory simulation system, using Carcinus maenas as the model organism, for assessing the impact of CO2 leakage from sub-seabed injection and storage.

    PubMed

    Rodríguez-Romero, Araceli; Jiménez-Tenorio, Natalia; Riba, Inmaculada; Blasco, Julián

    2016-01-01

    The capture and storage of CO2 in sub-seabed geological formations has been proposed as one of the potential options to decrease atmospheric CO2 concentrations in order to mitigate the abrupt and irreversible consequences of climate change. However, it is possible that CO2 leakages could occur during the injection and sequestration procedure, with significant repercussions for the marine environment. We investigate the effects of acidification derived from possible CO2 leakage events on the European green crab, Carcinus maenas. To this end, a lab-scale experiment involving direct release of CO2 was conducted at pH values between 7.7 and 6.15. Female crabs were exposed for 10 days to sediment collected from two different coastal areas, one with relatively uncontaminated sediment (RSP) and the other with known contaminated sediment (MZ and ML), under the pre-established seawater pH conditions. Survival rate, histopathological damage and metal (Fe, Mn, Cu, Zn, Cr, Cd and Pb) and As accumulation in gills and hepatopancreas tissue were employed as endpoints. In addition, the obtained results were compared with the results of the physico-chemical characterization of the sediments, which included the determination of the metals Fe, Mn, Cu, Zn, Cr, Pb and Cd, the metalloid As, certain polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), as well as nonchemical sediment properties (grain size, organic carbon and total organic matter). Significant associations were observed between pH and the histological damage. Concentrations of Fe, Mn, Cr, Pb, Cd and PAHs in sediment, presented significant negative correlations with the damage to gills and hepatopancreas, and positive correlations with metal accumulation in both tissues. The results obtained in this study reveal the importance of sediment properties in the biological effects caused by possible CO2 leakage. However, a clear pattern was not observed between metal accumulation in tissues and p

  5. Laboratory simulation system, using Carcinus maenas as the model organism, for assessing the impact of CO2 leakage from sub-seabed injection and storage.

    PubMed

    Rodríguez-Romero, Araceli; Jiménez-Tenorio, Natalia; Riba, Inmaculada; Blasco, Julián

    2016-01-01

    The capture and storage of CO2 in sub-seabed geological formations has been proposed as one of the potential options to decrease atmospheric CO2 concentrations in order to mitigate the abrupt and irreversible consequences of climate change. However, it is possible that CO2 leakages could occur during the injection and sequestration procedure, with significant repercussions for the marine environment. We investigate the effects of acidification derived from possible CO2 leakage events on the European green crab, Carcinus maenas. To this end, a lab-scale experiment involving direct release of CO2 was conducted at pH values between 7.7 and 6.15. Female crabs were exposed for 10 days to sediment collected from two different coastal areas, one with relatively uncontaminated sediment (RSP) and the other with known contaminated sediment (MZ and ML), under the pre-established seawater pH conditions. Survival rate, histopathological damage and metal (Fe, Mn, Cu, Zn, Cr, Cd and Pb) and As accumulation in gills and hepatopancreas tissue were employed as endpoints. In addition, the obtained results were compared with the results of the physico-chemical characterization of the sediments, which included the determination of the metals Fe, Mn, Cu, Zn, Cr, Pb and Cd, the metalloid As, certain polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), as well as nonchemical sediment properties (grain size, organic carbon and total organic matter). Significant associations were observed between pH and the histological damage. Concentrations of Fe, Mn, Cr, Pb, Cd and PAHs in sediment, presented significant negative correlations with the damage to gills and hepatopancreas, and positive correlations with metal accumulation in both tissues. The results obtained in this study reveal the importance of sediment properties in the biological effects caused by possible CO2 leakage. However, a clear pattern was not observed between metal accumulation in tissues and p

  6. Cryptic invasions of the crab Carcinus detected by molecular phylogeography.

    PubMed

    Geller, J B; Walton, E D; Grosholz, E D; Ruiz, G M

    1997-10-01

    Coastal marine ecosystems world-wide are threatened by invasions of nonindigenous species. The ubiquity of marine sibling species identifiable only by genetic analysis suggests that many invasions are cryptic and therefore undetected, causing an underestimation of the actual number and impacts of invading species. We test this hypothesis with European crabs in the genus Carcinus that have invaded five regions globally. Partial 16S ribosomal RNA gene sequences confirm sibling species status of morphologically similar Atlantic C. maenas and Mediterranean C. aestuarii. Based on 16S rRNA haplotypes, crabs from California, New England and Tasmania were all C. maenas. However, we report the cryptic multiple invasion of both species in Japan and South Africa, where only C. aestuarii and C. maenas, respectively, were previously recognized. PMID:9348700

  7. Mechanistic target of rapamycin (mTOR) signaling genes in decapod crustaceans: cloning and tissue expression of mTOR, Akt, Rheb, and p70 S6 kinase in the green crab, Carcinus maenas, and blackback land crab, Gecarcinus lateralis.

    PubMed

    Abuhagr, Ali M; Maclea, Kyle S; Chang, Ernest S; Mykles, Donald L

    2014-02-01

    Mechanistic target of rapamycin (mTOR) controls global translation of mRNA into protein by phosphorylating p70 S6 kinase (S6K) and eIF4E-binding protein-1. Akt and Rheb, a GTP-binding protein, regulate mTOR protein kinase activity. Molting in crustaceans is regulated by ecdysteroids synthesized by a pair of molting glands, or Y-organs (YOs), located in the cephalothorax. During premolt, the YOs hypertrophy and increase production of ecdysteroids. Rapamycin (1μM) inhibited ecdysteroid secretion in Carcinus maenas and Gecarcinus lateralis YOs in vitro, indicating that ecdysteroidogenesis requires mTOR-dependent protein synthesis. The effects of molting on the expression of four key mTOR signaling genes (mTOR, Akt, Rheb, and S6K) in the YO was investigated. Partial cDNAs encoding green crab (C. maenas) mTOR (4031bp), Akt (855bp), and S6K (918bp) were obtained from expressed sequence tags. Identity/similarity of the deduced amino acid sequence of the C. maenas cDNAs to human orthologs were 72%/81% for Cm-mTOR, 58%/73% for Cm-Akt, and 77%/88% for Cm-S6K. mTOR, Akt, S6K, and elongation factor 2 (EF2) in C. maenas and blackback land crab (G. lateralis) were expressed in all tissues examined. The two species differed in the effects of molting on gene expression in the YO. In G. lateralis, Gl-mTOR, Gl-Akt, and Gl-EF2 mRNA levels were increased during premolt. By contrast, molting had no effect on the expression of Cm-mTOR, Cm-Akt, Cm-S6K, Cm-Rheb, and Cm-EF2. These data suggest that YO activation during premolt involves up regulation of mTOR signaling genes in G. lateralis, but is not required in C. maenas. PMID:24269559

  8. Crustacean hyperglycaemic hormone (CHH)-like peptides and CHH-precursor-related peptides from pericardial organ neurosecretory cells in the shore crab, Carcinus maenas, are putatively spliced and modified products of multiple genes.

    PubMed Central

    Dircksen, H; Böcking, D; Heyn, U; Mandel, C; Chung, J S; Baggerman, G; Verhaert, P; Daufeldt, S; Plösch, T; Jaros, P P; Waelkens, E; Keller, R; Webster, S G

    2001-01-01

    About 24 intrinsic neurosecretory neurons within the pericardial organs (POs) of the crab Carcinus maenas produce a novel crustacean hyperglycaemic hormone (CHH)-like peptide (PO-CHH) and two CHH-precursor-related peptides (PO-CPRP I and II) as identified immunochemically and by peptide chemistry. Edman sequencing and MS revealed PO-CHH as a 73 amino acid peptide (8630 Da) with a free C-terminus. PO-CHH and sinus gland CHH (SG-CHH) share an identical N-terminal sequence, positions 1-40, but the remaining sequence, positions 41-73 or 41-72, differs considerably. PO-CHH may have different precursors, as cDNA cloning of PO-derived mRNAs has revealed several similar forms, one exactly encoding the peptide. All PO-CHH cDNAs contain a nucleotide stretch coding for the SG-CHH(41-76) sequence in the 3'-untranslated region (UTR). Cloning of crab testis genomic DNA revealed at least four CHH genes, the structure of which suggest that PO-CHH and SG-CHH arise by alternative splicing of precursors and possibly post-transcriptional modification of PO-CHH. The genes encode four exons, separated by three variable introns, encoding part of a signal peptide (exon I), the remaining signal peptide residues, a CPRP, the PO-CHH(1-40)/SG-CHH(1-40) sequences (exon II), the remaining PO-CHH residues (exon III) and the remaining SG-CHH residues and a 3'-UTR (exon IV). Precursor and gene structures are more closely related to those encoding related insect ion-transport peptides than to penaeid shrimp CHH genes. PO-CHH neither exhibits hyperglycaemic activity in vivo, nor does it inhibit Y-organ ecdysteroid synthesis in vitro. From the morphology of the neurons it seems likely that novel functions remain to be discovered. PMID:11336648

  9. First confirmation of human diarrhoeic poisonings by okadaic acid esters after ingestion of razor clams (Solen marginatus) and green crabs (Carcinus maenas) in Aveiro lagoon, Portugal and detection of okadaic acid esters in phytoplankton.

    PubMed

    Vale, Paulo; de M Sampayo, Maria Antónia

    2002-07-01

    A new outbreak of human diarrhoeic poisonings (DSP) with esters of okadaic acid (OA) was confirmed after ingestion of razor clams (Solen marginatus) harvested at Aveiro lagoon (NW Portugal) in the summer of 2001. Accumulation of marine toxins in second order consumers was investigated in the edible parts of a shellfish predator abundant at Aveiro lagoon, the green crab Carcinus maenas. Okadaic acid was found, also in a predominant esterified form. Levels in edible parts (comprising mainly viscera) surpassed 16microg/100g. We suggest that one patient may have developed profuse diarrhoea after ingestion of a large number of green crabs contaminated with okadaic acid esters. At least 32microg OA/100g were found in a remaining sample of its meal. Domoic acid was also found but under the allowable level in force in USA of 30microg/g crab viscera. In cooked crabs, significant losses of domoic acid were found and it is not suspected to have contributed to the poisoning event, although being a vector for this toxin. The low percentage of free okadaic acid found is in accordance with a predation predominantly on benthonic shellfish (razor clams, clams and common cockle) rather than on rock mussels. These last ones present usually higher percentages of free okadaic acid. Okadaic acid was confirmed with full-scan mass spectra either in plankton and mussel extracts. Okadaic acid esters were also found in plankton extracts. Percentages between 40-60% of esterified OA were found in samples freshly extracted. Ester's percentage diminished drastically if after sonication the extract was kept at room temperature. The major part of the esters was water-soluble. PMID:12076653

  10. Specific dynamic action in the shore crab, Carcinus maenas (L.), in relation to acclimation temperature and to the onset of the emersion response.

    PubMed

    Robertson, R F; Meagor, J; Taylor, E W

    2002-01-01

    The rate of oxygen uptake (MO(2)) of shore crabs following a period of fasting varied directly with acclimation temperature, with a Q(10) of 2.96 between 7 degrees and 15 degrees C and a Q(10) of 2.11 between 15 degrees and 22 degrees C. The factorial rise in MO(2) following a meal (specific dynamic action [SDA]) ranged between 1.9 and 3.1 and varied with temperature, being highest at 15 degrees C and significantly lower at both 7 degrees and 22 degrees C, despite similar ration sizes in all groups. At 7 degrees C, the SDA coefficient and magnitude were significantly lower than at 15 degrees C, possibly due in part to the inhibition of protein synthesis. Both the time to peak and the duration of the SDA response were inversely related to temperature. SDA coefficients were inversely related to the amount of food consumed. The critical oxygen tension of inspired water (P(I)O(2)), which evoked the emersion response in fasted animals, increased with temperature and further increased at each temperature when the animals were fed. Thus, the threshold P(I)O(2) evoking the emersion response is directly related to relative metabolic oxygen demand in Carcinus. PMID:12324891

  11. Overview on the European green crab Carcinus spp. (Portunidae, Decapoda), one of the most famous marine invaders and ecotoxicological models.

    PubMed

    Leignel, V; Stillman, J H; Baringou, S; Thabet, R; Metais, I

    2014-01-01

    Green crabs (Carcinus, Portunidae) include two species native to Europe--Carcinus aestuarii (Mediterranean species) and Carcinus maenas (Atlantic species). These small shore crabs (maximal length carapace, approximately 10 cm) show rapid growth, high fecundity, and long planktonic larval stages that facilitate broad dispersion. Carcinus spp. have a high tolerance to fluctuations of environmental factors including oxygen, salinity, temperature, xenobiotic compounds, and others. Shipping of Carcinus spp. over the past centuries has resulted in its invasions of America, Asia, and Australia. Classified as one of the world's 100 worst invaders by the International Union for Conservation of Nature, Carcinus spp. are the most widely distributed intertidal crabs in the world. Their voracious predatory activity makes them strong interactors in local communities, and they are recognized as a model for invasiveness in marine systems as well as a sentinel species in ecotoxicology. This review shows an exhaustive analysis of the literature on the life cycle, diversity, physiological tolerance, genomic investigations, ecotoxicological use, historical invasion, control programs, and putative economical valorization of shore crabs. PMID:24793074

  12. Overview on the European green crab Carcinus spp. (Portunidae, Decapoda), one of the most famous marine invaders and ecotoxicological models.

    PubMed

    Leignel, V; Stillman, J H; Baringou, S; Thabet, R; Metais, I

    2014-01-01

    Green crabs (Carcinus, Portunidae) include two species native to Europe--Carcinus aestuarii (Mediterranean species) and Carcinus maenas (Atlantic species). These small shore crabs (maximal length carapace, approximately 10 cm) show rapid growth, high fecundity, and long planktonic larval stages that facilitate broad dispersion. Carcinus spp. have a high tolerance to fluctuations of environmental factors including oxygen, salinity, temperature, xenobiotic compounds, and others. Shipping of Carcinus spp. over the past centuries has resulted in its invasions of America, Asia, and Australia. Classified as one of the world's 100 worst invaders by the International Union for Conservation of Nature, Carcinus spp. are the most widely distributed intertidal crabs in the world. Their voracious predatory activity makes them strong interactors in local communities, and they are recognized as a model for invasiveness in marine systems as well as a sentinel species in ecotoxicology. This review shows an exhaustive analysis of the literature on the life cycle, diversity, physiological tolerance, genomic investigations, ecotoxicological use, historical invasion, control programs, and putative economical valorization of shore crabs.

  13. Shock avoidance by discrimination learning in the shore crab (Carcinus maenas) is consistent with a key criterion for pain.

    PubMed

    Magee, Barry; Elwood, Robert W

    2013-02-01

    Nociception allows for immediate reflex withdrawal whereas pain allows for longer-term protection via rapid learning. We examine here whether shore crabs placed within a brightly lit chamber learn to avoid one of two dark shelters when that shelter consistently results in shock. Crabs were randomly selected to receive shock or not prior to making their first choice and were tested again over 10 trials. Those that received shock in trial 2, irrespective of shock in trial 1, were more likely to switch shelter choice in the next trial and thus showed rapid discrimination. During trial 1, many crabs emerged from the shock shelter and an increasing proportion emerged in later trials, thus avoiding shock by entering a normally avoided light area. In a final test we switched distinctive visual stimuli positioned above each shelter and/or changed the orientation of the crab when placed in the chamber for the test. The visual stimuli had no effect on choice, but crabs with altered orientation now selected the shock shelter, indicating that they had discriminated between the two shelters on the basis of movement direction. These data, and those of other recent experiments, are consistent with key criteria for pain experience and are broadly similar to those from vertebrate studies. PMID:23325857

  14. Potential use of the invasive European green crab (Carcinus maenas) as an ingredient in Atlantic Salmon (Salmo salar) diets; a preliminary analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atlantic salmon (Salmo salar) is an important cultured carnivorous species with wide comsumer acceptance. With the finite supply of available fishmeal and fish oil available for aquafeeds, research on and utilization of alternative protein and lipid sources is expandingWe examined the nutritional p...

  15. A developmental model for predicting handedness frequencies in crabs

    NASA Astrophysics Data System (ADS)

    Ladle, Richard J.; Todd, Peter A.

    2006-11-01

    Brachyuran crabs develop handedness in at least two different ways. Some crabs, such as Cancer productus, become heterochelous through use-induced differences in claw growth. Other crab species, for instance Carcinus maenas, appear to have a genetic predisposition towards right handedness. In this latter case, however, handedness reversal may take place following autotomy of the major claw. Thus, in C. maenas, and other species with this developmental strategy, younger cohorts are strongly biased towards right-handed individuals and the frequency of left-handedness increases with each subsequent moult. In the absence of differential mortality the ratio of left-handed to right-handed crabs in a given population should be predictable if the frequencies of right and left claw loss are known for different stages in the life history. Here, we develop a simple mathematical model for predicting handedness in crabs under the Carcinus-model of claw ontogeny and apply it to two species with very different ecologies and life histories; the green crab ( Carcinus maenas (L.)) and the Trinidadian mountain crab ( Eudaniela garmani (Rathburn)). The predicted and observed handedness frequencies were in complete concordance for the early intermoults of both species but significantly deviated in mature C. maenas where left-handed individuals were under-represented in the population. These results are discussed in the context of the evolution and functional significance of claw autotomy and handedness in crabs.

  16. Physiological effects of metal toxicity on the tropical freshwater shrimp Microbrachium carcinus (Linneo, 1758).

    PubMed

    Correa, M

    1987-01-01

    Pilot tests were performed to determine the level at which Zn(++) and Cu(++) ceased to be acutely toxic in Macrobrachium carcinus. The data indicated that the static 96h-LC(50) values for Zn(++) and Cu(++) were 0.2 and 0.1 mg litre(-1) respectively. A differential reduction in respiration and ammonia excretion rates was noted with increasing concentrations of these metals in the water. These levels may in a toxic body burden and a progressive deterioration of gill efficiency. A decrease in respiration and ammonia excretion rates resulted in a decrease in O:N ratios, upon exposure to Zn(++) and Cu(++) concentrations. The ratios obtained indicate that these metals, also increased dependence on carbohydrate or lipid reserves.

  17. [Nutrition of juvenile prawn Macrobrachium carcinus (Crustacea: Decapoda) with diets of vegetable and marine residues].

    PubMed

    Casas-Sánchez, R; Vaillard-Nava, Y; Re-Araujo, A D

    1995-01-01

    Juvenile prawn Macrobrachium carcinus were fed two different diets: restaurant by-products (diet I) and fish and vegetable market by-products (diet II). These diets were evaluated by proximal analysis, assimilation efficiency and the factor conversion rate (FCR). Diet I registered a higher efficiency, but there was no difference in the growth rate. The growth mean (G. L.) for three months was 0.254 +/- 0.13 cm (diet I) and 0.191 +/- 0.1 cm (diet II). The conversion rate was good for both, suggesting that 6 to 7 kg of food are needed to obtain 1 kg of prawn. Survival was 76% and 100% for diets I and II, respectively.

  18. Genetics

    MedlinePlus

    ... Inheritance; Heterozygous; Inheritance patterns; Heredity and disease; Heritable; Genetic markers ... The chromosomes are made up of strands of genetic information called DNA. Each chromosome contains sections of ...

  19. Can starvation influence cellular and biochemical parameters in the crab Carcinus aestuarii?

    PubMed

    Matozzo, Valerio; Gallo, Chiara; Marin, Maria Gabriella

    2011-04-01

    Crustacea experience periods of starvation during moulting or when limited food availability occurs. The effects of starvation on Crustacea physiological responses have been demonstrated, whereas the effects of starvation on Crustacea immune parameters remain to be more fully studied. In the present study the effects of starvation on immune parameters and antioxidant enzyme activities of the crab Carcinus aestuarii were evaluated for the first time. Treated crabs were starved for 7 days, whereas control crabs were fed daily with mussels. Total haemocyte count (THC), haemocyte diameter and volume, haemocyte proliferation, cell-free haemolymph (CFH) glucose and total protein levels, and phenoloxidase (PO) activity in both haemocyte lysate (HL) and CFH were measured in crabs. In addition, superoxide dismutase (SOD) and catalase (CAT) activities were evaluated in both gills and digestive gland from crabs, in order to evaluate whether starvation induced oxidative stress in C. aestuarii. THC increased significantly in starved crabs, with respect to controls, whereas no significant variations were observed in haemocyte diameter, volume and proliferation. In CFH of starved animals glucose concentration significantly increased, whereas total protein concentration significantly reduced. A significantly higher PO activity was recorded in HL from starved crabs, than in control crabs. Conversely, PO activity did not vary significantly in CFH. Starvation did not cause significant alterations in antioxidant enzyme activities in both gills and digestive gland. Results obtained demonstrated that starvation influenced crab immune parameters, but did not induce oxidative stress. Results also indicated that C. aestuarii can modulate its cellular and biochemical parameters in order to cope with starvation.

  20. Experimental evidence for latent developmental plasticity: intertidal whelks respond to a native but not an introduced predator.

    PubMed

    Edgell, Timothy C; Neufeld, Christopher J

    2008-08-23

    Animals with highly inducible traits may show no inducible response when exposed to a related but wholly novel cue. This appears to be true for the intertidal whelk Nucella lamellosa faced with a voracious introduced predator. In the laboratory, we exposed whelks to effluent from two species of predatory crab, the native red rock crab Cancer productus and the invasive European green crab Carcinus maenas. Nucella and Cancer have a long shared history in the northeast Pacific, whereas potential interaction with Carcinus began here less than 10 years ago. Although Nucella responded adaptively to Cancer effluent by increasing shell thickness and decreasing somatic growth, there was no such response to Carcinus. Furthermore, thicker shelled Nucella were less likely to be eaten by Carcinus. Because Nucella produces thicker shells when exposed to Cancer cues, its ability to respond similarly to Carcinus depends only on the coupling of the Carcinus cue to the existing developmental pathways for adaptive changes in shell form. Such coupling of latent plasticity to a novel cue -- via genetic changes or associative learning -- could explain many cases of rapid phenotypic change following a sudden shift in the environment.

  1. First cytochemical study of haemocytes from the crab Carcinus aestuarii (Crustacea, Decapoda)

    PubMed Central

    Matozzo, V.; Marin, M.G.

    2010-01-01

    For the first time, a morphological study of haemocytes from the crab Carcinus aestuarii was carried out by means of light microscopy and differing cytochemical assays. Analysis of haemocyte size frequency distribution (performed by means of a Coulter Counter) revealed the presence of two distinct haemocyte fractions in C. aestuarii haemolymph, depending on cell size. The first fraction was of about 3–5 µm in diameter and 30–50 fL in volume, the second was of about 6–12 µm in diameter and over 200 fL in volume. Mean cell diameter and volume were 8.20±1.7 µm and 272.30±143.5 fL, respectively. Haemocytes observed under light microscope were distinguished in three cell types: granulocytes (28%; 11.94±1.43 µm in diameter) with evident cytoplasmic granules, semigranulocytes (27%; 12.38±1.76 µm in diameter) with less granules than granulocytes, and hyalinocytes (44%; 7.88±1.6 µm in diameter) without granules. In addition, a peculiar cell type was occasionally found (about 1%): it was 25–30 µm in diameter and had a great vacuole and a peripheral cytoplasm with granules. Granulocyte and semigranulocyte granules stained in vivo with Neutral Red, indicating that they were lysosomes. Giemsa’s dye confirmed that granulocytes and semigranulocytes were larger than hyalinocytes. Pappenheim’s panoptical staining and Ehrlich’s triacid mixture allowed to distinguish granule-containing cells (including semigranulocytes) in acidophils (64%), basophils (35%) and neutrophils (1%). Hyalinocytes showed always a basophilic cytoplasm. Haemocytes were positive to the PAS reaction for carbohydrates, even if cytoplasm carbohydrate distribution varied among cell types. Lastly, lipids were found on cell membrane and in cytoplasm of all haemocyte types in the form of black spots produced after Sudan Black B staining. The morphological characterisation of C. aestuarii haemocytes by light microscopy was necessary before performing both ultrastructural and functional

  2. Genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Capsicum represents one of several well characterized Solanaceous genera. A wealth of classical and molecular genetics research is available for the genus. Information gleaned from its cultivated relatives, tomato and potato, provide further insight for basic and applied studies. Early ...

  3. Genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maintaining genetic variation in wild populations of Arctic organisms is fundamental to the long-term persistence of high latitude biodiversity. Variability is important because it provides options for species to respond to changing environmental conditions and novel challenges such as emerging path...

  4. An ENA ATPase, MaENA1, of Metarhizium acridum influences the Na(+)-, thermo- and UV-tolerances of conidia and is involved in multiple mechanisms of stress tolerance.

    PubMed

    Ma, Qinsi; Jin, Kai; Peng, Guoxiong; Xia, Yuxian

    2015-10-01

    In fungi, ENA ATPases play key roles in osmotic and alkaline pH tolerance, although their functions in thermo- and UV-tolerances have not been explored. Entomopathogenic fungi are naturally widespread and have considerable potential in pest control. An ENA ATPase gene, MaENA1, from the entomopathogenic fungus Metarhizium acridum was functionally analyzed by deletion. MaENA1-disruption strain (ΔMaENA1) was less tolerant to NaCl, heat, and UV radiation than a wild-type strain (WT). Digital Gene Expression profiling of conidial RNAs resulted in 281 differentially expressed genes (DEGs) between the WT and ΔMaENA1 strains. Eighty-five DEGs, 56 of which were down-regulated in the ΔMaENA1 strain, were shown to be associated with heat/UV tolerance, including six cytochrome P450 superfamily genes, 35 oxidoreductase genes, 24 ion-binding genes, seven DNA repair genes, and five other genes. In addition, eight genes were components of stress responsive pathways, including the Ras-cAMP PKA pathway, the RIM101 pathway, the Ca(2+)/calmodulin pathway, the TOR pathway, and the HOG/Spc1/Sty1/JNK pathway. These results demonstrated that MaENA1 influences fungal tolerances to Na(+), heat, and UV radiation in M. acridum, and is involved in multiple mechanisms of stress tolerance. Therefore, MaENA1 is required for the adaptation and survival of entomopathogenic fungi in stressful conditions in the environment and in their hosts.

  5. Solution structures of 2×6-meric and 4×6-meric hemocyanins of crustaceans Carcinus aestuarii, Squilla mantis and Upogebia pusilla.

    PubMed

    Mičetić, Ivan; Losasso, Carmen; Muro, Paolo Di; Tognon, Giuseppe; Benedetti, Piero; Beltramini, Mariano

    2010-07-01

    Arthropod hemocyanins (Hcs) are a family of large, high molecular mass, extracellular oxygen transport proteins. They form oligomeric quaternary structures based on different arrangements of a basic 6×75 kDa hexameric unit. Their complex quaternary structures present binding sites for allosteric effectors and regulate the oxygen binding process in a cooperative manner. In order to describe the functional regulation of arthropod Hcs, a detailed description of their quaternary structure is necessary. We have utilized small angle X-ray scattering to characterize the structure of three arthropod Hcs in unperturbed conditions. Two different levels of complexity are evaluated: for the 2×6-meric case, we analyzed the Hcs of the portunid crab Carcinus aestuarii and stomatopod Squilla mantis, while in the case of 4×6-meric structures, we studied the Hc of the thalassinid shrimp Upogebia pusilla. While C. aestuarii Hc presented a structure comparable to other 2×6-meric crustacean Hcs, S. mantis Hc shows a peculiar and quite unique arrangement of its building blocks, resembling a substructure of giant Hcs found among cheliceratans. For U. pusilla, the arrangement of its subunits is described as tetrahedral, in contrast to the more common square planar 4×6-meric structure found in other arthropod Hcs. PMID:20350602

  6. Intense natural selection caused a rapid morphological transition in a living marine snail

    PubMed Central

    Seeley, Robin Hadlock

    1986-01-01

    Shell shape and shell thickness of the intertidal snail Littorina obtusata changed markedly between 1871 and 1984 in northern New England. Shells collected prior to 1900 were high-spired with thin walls, whereas shells collected in 1982-84 were low-spired with thick walls. An intertidal crab (Carcinus maenas) which preys on L. obtusata expanded its range into northern New England around 1900. This suggests that the change in snail shell form was a response to predation by Carcinus. Field and laboratory experiments demonstrated that the high-spired form of L. obtusata, which can still be found in some Maine localities, is more vulnerable to predation by Carcinus than is the low-spired form of L. obtusata. Electrophoretic comparisons of high- and low-spired populations of L. obtusata confirmed that these populations represent different morphological forms of L. obtusata rather than different species [Nei's D (unbiased measure of genetic distance) = 0.003]. These data demonstrate that classical Darwinian selection can produce a rapid morphological transition without speciation. Images PMID:16593760

  7. Intense natural selection caused a rapid morphological transition in a living marine snail.

    PubMed

    Seeley, R H

    1986-09-01

    Shell shape and shell thickness of the intertidal snail Littorina obtusata changed markedly between 1871 and 1984 in northern New England. Shells collected prior to 1900 were high-spired with thin walls, whereas shells collected in 1982-84 were low-spired with thick walls. An intertidal crab (Carcinus maenas) which preys on L. obtusata expanded its range into northern New England around 1900. This suggests that the change in snail shell form was a response to predation by Carcinus. Field and laboratory experiments demonstrated that the high-spired form of L. obtusata, which can still be found in some Maine localities, is more vulnerable to predation by Carcinus than is the low-spired form of L. obtusata. Electrophoretic comparisons of high- and low-spired populations of L. obtusata confirmed that these populations represent different morphological forms of L. obtusata rather than different species [Nei's D (unbiased measure of genetic distance) = 0.003]. These data demonstrate that classical Darwinian selection can produce a rapid morphological transition without speciation. PMID:16593760

  8. [Genetics and genetic counseling].

    PubMed

    Izzi, Claudia; Liut, Francesca; Dallera, Nadia; Mazza, Cinzia; Magistroni, Riccardo; Savoldi, Gianfranco; Scolari, Francesco

    2016-01-01

    Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most frequent genetic disease, characterized by progressive development of bilateral renal cysts. Two causative genes have been identified: PKD1 and PKD2. ADPKD phenotype is highly variable. Typically, ADPKD is an adult onset disease. However, occasionally, ADPKD manifests as very early onset disease. The phenotypic variability of ADPKD can be explained at three genetic levels: genic, allelic and gene modifier effects. Recent advances in molecular screening for PKD gene mutations and the introduction of the new next generation sequencing (NGS)- based genotyping approach have generated considerable improvement regarding the knowledge of genetic basis of ADPKD. The purpose of this article is to provide a comprehensive review of the genetics of ADPKD, focusing on new insights in genotype-phenotype correlation and exploring novel clinical approach to genetic testing. Evaluation of these new genetic information requires a multidisciplinary approach involving a nephrologist and a clinical geneticist. PMID:27067213

  9. Matching oceanography and genetics at the basin scale. Seascape connectivity of the Mediterranean shore crab in the Adriatic Sea.

    PubMed

    Schiavina, M; Marino, I A M; Zane, L; Melià, P

    2014-11-01

    Investigating the interactions between the physical environment and early life history is crucial to understand the mechanisms that shape the genetic structure of marine populations. Here, we assessed the genetic differentiation in a species with larval dispersal, the Mediterranean shore crab (Carcinus aestuarii) in the Adriatic Sea (central Mediterranean), and we investigated the role of oceanic circulation in shaping population structure. To this end, we screened 11 polymorphic microsatellite loci from 431 individuals collected at eight different sites. We found a weak, yet significant, genetic structure into three major clusters: a northern Adriatic group, a central Adriatic group and one group including samples from southern Adriatic and Ionian seas. Genetic analyses were compared, under a seascape genetics approach, with estimates of potential larval connectivity obtained with a coupled physical-biological model that integrates a water circulation model and a description of biological traits affecting dispersal. The cross-validation of the results of the two approaches supported the view that genetic differentiation reflects an oceanographic subdivision of the Adriatic Sea into three subbasins, with circulation patterns allowing the exchange of larvae through permanent connections linking north Adriatic sites and ephemeral connections like those linking the central Adriatic with northern and southern locations.

  10. Medical genetics

    SciTech Connect

    Nora, J.J.; Fraser, F.C.

    1989-01-01

    This book presents a discussion of medical genetics for the practitioner treating or counseling patients with genetic disease. It includes a discussion of the relationship of heredity and diseases, the chromosomal basis for heredity, gene frequencies, and genetics of development and maldevelopment. The authors also focus on teratology, somatic cell genetics, genetics and cancer, genetics of behavior.

  11. Medical genetics

    SciTech Connect

    Jorde, L.B.; Carey, J.C.; White, R.L.

    1995-10-01

    This book on the subject of medical genetics is a textbook aimed at a very broad audience: principally, medical students, nursing students, graduate, and undergraduate students. The book is actually a primer of general genetics as applied to humans and provides a well-balanced introduction to the scientific and clinical basis of human genetics. The twelve chapters include: Introduction, Basic Cell Biology, Genetic Variation, Autosomal Dominant and Recessive Inheritance, Sex-linked and Mitochondrial Inheritance, Clinical Cytogenetics, Gene Mapping, Immunogenetics, Cancer Genetics, Multifactorial Inheritance and Common Disease, Genetic Screening, Genetic Diagnosis and Gene Therapy, and Clinical Genetics and Genetic Counseling.

  12. Genetic algorithms

    NASA Technical Reports Server (NTRS)

    Wang, Lui; Bayer, Steven E.

    1991-01-01

    Genetic algorithms are mathematical, highly parallel, adaptive search procedures (i.e., problem solving methods) based loosely on the processes of natural genetics and Darwinian survival of the fittest. Basic genetic algorithms concepts are introduced, genetic algorithm applications are introduced, and results are presented from a project to develop a software tool that will enable the widespread use of genetic algorithm technology.

  13. New Genetics

    MedlinePlus

    ... human genome, behavioral genetics, pharmacogenetics, drug resistance, biofilms, computer modeling. » more Chapter 5: 21st-Century Genetics Covers systems biology, GFP, genetic testing, privacy concerns, DNA forensics, ...

  14. Genetic Counseling

    MedlinePlus

    Genetic counseling provides information and support to people who have, or may be at risk for, genetic disorders. A ... meets with you to discuss genetic risks. The counseling may be for yourself or a family member. ...

  15. Genetic Counseling

    MedlinePlus

    ... Articles Genetic Counseling Information For... Media Policy Makers Genetic Counseling Language: English Español (Spanish) Recommend on Facebook ... informed decisions about testing and treatment. Reasons for Genetic Counseling There are many reasons that people go ...

  16. Asymmetric dispersal allows an upstream region to control population structure throughout a species' range.

    PubMed

    Pringle, James M; Blakeslee, April M H; Byers, James E; Roman, Joe

    2011-09-13

    In a single well-mixed population, equally abundant neutral alleles are equally likely to persist. However, in spatially complex populations structured by an asymmetric dispersal mechanism, such as a coastal population where larvae are predominantly moved downstream by currents, the eventual frequency of neutral haplotypes will depend on their initial spatial location. In our study of the progression of two spatially separate, genetically distinct introductions of the European green crab (Carcinus maenas) along the coast of eastern North America, we captured this process in action. We documented the shift of the genetic cline in this species over 8 y, and here we detail how the upstream haplotypes are beginning to dominate the system. This quantification of an evolving genetic boundary in a coastal system demonstrates that novel genetic alleles or haplotypes that arise or are introduced into upstream retention zones (regions whose export of larvae is not balanced by import from elsewhere) will increase in frequency in the entire system. This phenomenon should be widespread when there is asymmetrical dispersal, in the oceans or on land, suggesting that the upstream edge of a species' range can influence genetic diversity throughout its distribution. Efforts to protect the upstream edge of an asymmetrically dispersing species' range are vital to conserving genetic diversity in the species. PMID:21876126

  17. Genetic Mapping

    MedlinePlus

    ... Genetic Education Resources for Teachers Genomic Careers National DNA Day Online Education Kit Online Genetics Education Resources ... prevalent. Using various laboratory techniques, the scientists isolate DNA from these samples and examine it for unique ...

  18. Genetic Disorders

    MedlinePlus

    ... This can cause a medical condition called a genetic disorder. You can inherit a gene mutation from ... during your lifetime. There are three types of genetic disorders: Single-gene disorders, where a mutation affects ...

  19. Genetic modification and genetic determinism

    PubMed Central

    Resnik, David B; Vorhaus, Daniel B

    2006-01-01

    In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions. PMID:16800884

  20. Genetic principles.

    PubMed

    Abuelo, D

    1987-01-01

    The author discusses the basic principles of genetics, including the classification of genetic disorders and a consideration of the rules and mechanisms of inheritance. The most common pitfalls in clinical genetic diagnosis are described, with emphasis on the problem of the negative or misleading family history.

  1. Imaging Genetics

    ERIC Educational Resources Information Center

    Munoz, Karen E.; Hyde, Luke W.; Hariri, Ahmad R.

    2009-01-01

    Imaging genetics is an experimental strategy that integrates molecular genetics and neuroimaging technology to examine biological mechanisms that mediate differences in behavior and the risks for psychiatric disorder. The basic principles in imaging genetics and the development of the field are discussed.

  2. Genetic Testing

    MedlinePlus

    ... genetic tests for several reasons. These include Finding genetic diseases in unborn babies Finding out if people carry a gene for a disease and might pass it on to their children Screening embryos for disease Testing for genetic diseases in adults before they cause ...

  3. Thermal stress and predation risk trigger distinct transcriptomic responses in the intertidal snail Nucella lapillus.

    PubMed

    Chu, Nathaniel D; Miller, Luke P; Kaluziak, Stefan T; Trussell, Geoffrey C; Vollmer, Steven V

    2014-12-01

    Thermal stress and predation risk have profound effects on rocky shore organisms, triggering changes in their feeding behaviour, morphology and metabolism. Studies of thermal stress have shown that underpinning such changes in several intertidal species are specific shifts in gene and protein expression (e.g. upregulation of heat-shock proteins). But relatively few studies have examined genetic responses to predation risk. Here, we use next-generation RNA sequencing (RNA-seq) to examine the transcriptomic (mRNA) response of the snail Nucella lapillus to thermal stress and predation risk. We found that like other intertidal species, N. lapillus displays a pronounced genetic response to thermal stress by upregulating many heat-shock proteins and other molecular chaperones. In contrast, the presence of a crab predator (Carcinus maenas) triggered few significant changes in gene expression in our experiment, and this response showed no significant overlap with the snail's response to thermal stress. These different gene expression profiles suggest that thermal stress and predation risk could pose distinct and potentially additive challenges for N. lapillus and that genetic responses to biotic stresses such as predation risk might be more complex and less uniform across species than genetic responses to abiotic stresses such as thermal stress.

  4. Thermal stress and predation risk trigger distinct transcriptomic responses in the intertidal snail Nucella lapillus.

    PubMed

    Chu, Nathaniel D; Miller, Luke P; Kaluziak, Stefan T; Trussell, Geoffrey C; Vollmer, Steven V

    2014-12-01

    Thermal stress and predation risk have profound effects on rocky shore organisms, triggering changes in their feeding behaviour, morphology and metabolism. Studies of thermal stress have shown that underpinning such changes in several intertidal species are specific shifts in gene and protein expression (e.g. upregulation of heat-shock proteins). But relatively few studies have examined genetic responses to predation risk. Here, we use next-generation RNA sequencing (RNA-seq) to examine the transcriptomic (mRNA) response of the snail Nucella lapillus to thermal stress and predation risk. We found that like other intertidal species, N. lapillus displays a pronounced genetic response to thermal stress by upregulating many heat-shock proteins and other molecular chaperones. In contrast, the presence of a crab predator (Carcinus maenas) triggered few significant changes in gene expression in our experiment, and this response showed no significant overlap with the snail's response to thermal stress. These different gene expression profiles suggest that thermal stress and predation risk could pose distinct and potentially additive challenges for N. lapillus and that genetic responses to biotic stresses such as predation risk might be more complex and less uniform across species than genetic responses to abiotic stresses such as thermal stress. PMID:25377436

  5. [Experimental study of vibrio parahaemolyticus (biotype 2) transfer from water and sediments to benthic marine food chain organisms].

    PubMed

    Gauthier, M J; Clement, R

    1979-04-01

    Transfer of Vibrio parahaemolyticus (biotype 2) from sediments to water and from water to benthic marine organisms was studied experimentally using a streptomycin-resistant strain. Transmission by trophic pathways was also studied using reconstituted marine food chains (Mytilus edulis, Nereis diversicolor, Carcinus maenas, Scorpaena porcus, Mus musculus). Water colonization by sediments could be observed only at temperatures above 16 degrees C. Sediments could well constitute a disseminating reservoir for these germs, their cycle in water being dependent of the cycle followed in the sediments. Contamination of animal organisms is essentially effected by a direct mean, either water or sediments; transfer by trophic pathways being negligible. Infection of land consumers (mice) is linked quantitatively to the nature of the last marine organism of the food chain since bacteria can flourish in the digestive tract of certain animals (Carcinus maenas). PMID:487292

  6. Genetic barcodes

    DOEpatents

    Weier, Heinz -Ulrich G

    2015-08-04

    Herein are described multicolor FISH probe sets termed "genetic barcodes" targeting several cancer or disease-related loci to assess gene rearrangements and copy number changes in tumor cells. Two, three or more different fluorophores are used to detect the genetic barcode sections thus permitting unique labeling and multilocus analysis in individual cell nuclei. Gene specific barcodes can be generated and combined to provide both numerical and structural genetic information for these and other pertinent disease associated genes.

  7. Paleopopulation genetics.

    PubMed

    Wall, Jeffrey D; Slatkin, Montgomery

    2012-01-01

    Paleopopulation genetics is a new field that focuses on the population genetics of extinct groups and ancestral populations (i.e., populations ancestral to extant groups). With recent advances in DNA sequencing technologies, we now have unprecedented ability to directly assay genetic variation from fossils. This allows us to address issues, such as past population structure, changes in population size, and evolutionary relationships between taxa, at a much greater resolution than can traditional population genetics studies. In this review, we discuss recent developments in this emerging field as well as prospects for the future. PMID:22994357

  8. Genetic Engineering

    ERIC Educational Resources Information Center

    Phillips, John

    1973-01-01

    Presents a review of genetic engineering, in which the genotypes of plants and animals (including human genotypes) may be manipulated for the benefit of the human species. Discusses associated problems and solutions and provides an extensive bibliography of literature relating to genetic engineering. (JR)

  9. Diluting the founder effect: cryptic invasions expand a marine invader's range

    PubMed Central

    Roman, Joe

    2006-01-01

    Most invasion histories include an estimated arrival time, followed by range expansion. Yet, such linear progression may not tell the entire story. The European green crab (Carcinus maenas) was first recorded in the US in 1817, followed by an episodic expansion of range to the north. Its population has recently exploded in the Canadian Maritimes. Although it has been suggested that this northern expansion is the result of warming sea temperatures or cold-water adaptation, Canadian populations have higher genetic diversity than southern populations, indicating that multiple introductions have occurred in the Maritimes since the 1980s. These new genetic lineages, probably from the northern end of the green crab's native range in Europe, persist in areas that were once thought to be too cold for the original southern invasion front. It is well established that ballast water can contain a wide array of nonindigenous species. Ballast discharge can also deliver genetic variation on a level comparable to that of native populations. Such gene flow not only increases the likelihood of persistence of invasive species, but it can also rapidly expand the range of long-established nonindigenous species. PMID:16959635

  10. Diluting the founder effect: cryptic invasions expand a marine invader's range.

    PubMed

    Roman, Joe

    2006-10-01

    Most invasion histories include an estimated arrival time, followed by range expansion. Yet, such linear progression may not tell the entire story. The European green crab (Carcinus maenas) was first recorded in the US in 1817, followed by an episodic expansion of range to the north. Its population has recently exploded in the Canadian Maritimes. Although it has been suggested that this northern expansion is the result of warming sea temperatures or cold-water adaptation, Canadian populations have higher genetic diversity than southern populations, indicating that multiple introductions have occurred in the Maritimes since the 1980s. These new genetic lineages, probably from the northern end of the green crab's native range in Europe, persist in areas that were once thought to be too cold for the original southern invasion front. It is well established that ballast water can contain a wide array of nonindigenous species. Ballast discharge can also deliver genetic variation on a level comparable to that of native populations. Such gene flow not only increases the likelihood of persistence of invasive species, but it can also rapidly expand the range of long-established nonindigenous species. PMID:16959635

  11. Community shelter use in response to two benthic decapod predators in the Long Island Sound.

    PubMed

    Hudson, David M; Reagan, Dugan; Crivello, Joseph F

    2016-01-01

    To investigate community shelter effects of two invasive decapod species, Hemigrapsus sanguineus and Carcinus maenas, in the Long Island Sound (LIS), we deployed artificial shelters in the intertidal and immediate subtidal zones. These consisted of five groups during the summer: a control, a resident H. sanguineus male or female group, and a resident C. maenas male or female group. We quantified utilization of the shelters at 24 h by counting crabs and fish present. We found significant avoidance of H. sanguineus in the field by benthic hermit crabs (Pagurus spp.) and significant avoidance of C. maenas by the seaboard goby (Gobiosoma ginsburgi). The grubby (Myoxocephalus aenaeus) avoided neither treatment, probably since it tends to be a predator of invertebrates. H. sanguineus avoided C. maenas treatments, whereas C. maenas did not avoid any treatment. Seasonal deployments in the subtidal indicated cohabitation of a number of benthic species in the LIS, with peak shelter use corresponding with increased predation and likely reproductive activity in spring and summer for green crabs (C. maenas), hermit crabs (Pagurus spp.), seaboard gobies (G. ginsburgi), and grubbies (Myoxocephalus aenaeus).

  12. Community shelter use in response to two benthic decapod predators in the Long Island Sound

    PubMed Central

    Reagan, Dugan; Crivello, Joseph F.

    2016-01-01

    To investigate community shelter effects of two invasive decapod species, Hemigrapsus sanguineus and Carcinus maenas, in the Long Island Sound (LIS), we deployed artificial shelters in the intertidal and immediate subtidal zones. These consisted of five groups during the summer: a control, a resident H. sanguineus male or female group, and a resident C. maenas male or female group. We quantified utilization of the shelters at 24 h by counting crabs and fish present. We found significant avoidance of H. sanguineus in the field by benthic hermit crabs (Pagurus spp.) and significant avoidance of C. maenas by the seaboard goby (Gobiosoma ginsburgi). The grubby (Myoxocephalus aenaeus) avoided neither treatment, probably since it tends to be a predator of invertebrates. H. sanguineus avoided C. maenas treatments, whereas C. maenas did not avoid any treatment. Seasonal deployments in the subtidal indicated cohabitation of a number of benthic species in the LIS, with peak shelter use corresponding with increased predation and likely reproductive activity in spring and summer for green crabs (C. maenas), hermit crabs (Pagurus spp.), seaboard gobies (G. ginsburgi), and grubbies (Myoxocephalus aenaeus). PMID:27547570

  13. Community shelter use in response to two benthic decapod predators in the Long Island Sound.

    PubMed

    Hudson, David M; Reagan, Dugan; Crivello, Joseph F

    2016-01-01

    To investigate community shelter effects of two invasive decapod species, Hemigrapsus sanguineus and Carcinus maenas, in the Long Island Sound (LIS), we deployed artificial shelters in the intertidal and immediate subtidal zones. These consisted of five groups during the summer: a control, a resident H. sanguineus male or female group, and a resident C. maenas male or female group. We quantified utilization of the shelters at 24 h by counting crabs and fish present. We found significant avoidance of H. sanguineus in the field by benthic hermit crabs (Pagurus spp.) and significant avoidance of C. maenas by the seaboard goby (Gobiosoma ginsburgi). The grubby (Myoxocephalus aenaeus) avoided neither treatment, probably since it tends to be a predator of invertebrates. H. sanguineus avoided C. maenas treatments, whereas C. maenas did not avoid any treatment. Seasonal deployments in the subtidal indicated cohabitation of a number of benthic species in the LIS, with peak shelter use corresponding with increased predation and likely reproductive activity in spring and summer for green crabs (C. maenas), hermit crabs (Pagurus spp.), seaboard gobies (G. ginsburgi), and grubbies (Myoxocephalus aenaeus). PMID:27547570

  14. Arthropod Genetics.

    ERIC Educational Resources Information Center

    Zumwalde, Sharon

    2000-01-01

    Introduces an activity on arthropod genetics that involves phenotype and genotype identification of the creature and the construction process. Includes a list of required materials and directions to build a model arthropod. (YDS)

  15. Genetic Discrimination

    MedlinePlus

    ... Medicine Working Group New Horizons and Research Patient Management Policy and Ethics Issues Quick Links for Patient Care ... genetic discrimination. April 25, 2007, Statement of Administration Policy, Office of Management and Budget Official Statement from the Office of ...

  16. Ciona Genetics

    PubMed Central

    Veeman, Michael T.; Chiba, Shota; Smith, William C.

    2010-01-01

    Ascidians, such as Ciona, are invertebrate chordates with simple embryonic body plans and small, relatively non-redundant genomes. Ciona genetics is in its infancy compared to many other model systems, but it provides a powerful method for studying this important vertebrate outgroup. Here we give basic methods for genetic analysis of Ciona, including protocols for controlled crosses both by natural spawning and by the surgical isolation of gametes; the identification and propagation of mutant lines; and strategies for positional cloning. PMID:21805273

  17. Plastic parasites: extreme dimorphism creates a taxonomic conundrum in the phylum Microsporidia.

    PubMed

    Stentiford, G D; Bateman, K S; Feist, S W; Chambers, E; Stone, D M

    2013-04-01

    In this paper, we combine field observations of highly statistically significant co-occurrence with histopathological, ultrastructural and molecular phylogenetic analyses, to provide evidence for extreme morphological plasticity in a microsporidium parasite infecting the musculature of marine crabs. The parasite appears to alternate between lineages that culminate in production of either bizarre needle-like spores in the peripheral sarcoplasm of heart and skeletal muscle fibres (reminiscent of Nadelspora canceri infecting Cancer magister) or alternatively, Ameson-like spores with pronounced surface projections, in the skeletal muscles (as for Ameson pulvis, previously described infecting Carcinus maenas). Both lineages occur in direct contact with the cytoplasm of host muscle cells and can exist simultaneously within the same cell. Pathological data appears to reveal a remarkable shift in morphology during pathogenic remodelling of host tissues. Sequence analysis of multiple clones derived from amplification of the ssrRNA gene from infected regions of the heart and skeletal muscles appear to confirm the genetic identity of the two lineages. Furthermore, derived ssrRNA gene sequences are more similar (>99%) to N. canceri than to the coparasite Ameson michaelis infecting Callinectes sapidus (93%). Although molecular phylogenetic data support transfer of A. pulvis into the genus Nadelspora, the expansion in the generic description required to include such widely divergent characteristics is so significant as to be unfeasible within the current taxonomic framework of the phylum Microsporidia. At present, it is preferable to propose that the parasite infecting C. maenas forms a clade with other morphologically diverse but phylogenetically and ecologically similar muscle-infecting microsporidians from marine crustacean hosts. Given the strong evidence for significant plasticity in morphology amongst members of the phylum Microsporidia, novel approaches to phylogeny

  18. Model-Derived Dispersal Pathways from Multiple Source Populations Explain Variability of Invertebrate Larval Supply

    PubMed Central

    Domingues, Carla P.; Nolasco, Rita; Dubert, Jesus; Queiroga, Henrique

    2012-01-01

    Background Predicting the spatial and temporal patterns of marine larval dispersal and supply is a challenging task due to the small size of the larvae and the variability of oceanographic processes. Addressing this problem requires the use of novel approaches capable of capturing the inherent variability in the mechanisms involved. Methodology/Principal Findings In this study we test whether dispersal and connectivity patterns generated from a bio-physical model of larval dispersal of the crab Carcinus maenas, along the west coast of the Iberian Peninsula, can predict the highly variable daily pattern of wind-driven larval supply to an estuary observed during the peak reproductive season (March–June) in 2006 and 2007. Cross-correlations between observed and predicted supply were significant (p<0.05) and strong, ranging from 0.34 to 0.81 at time lags of −6 to +5 d. Importantly, the model correctly predicted observed cross-shelf distributions (Pearson r = 0.82, p<0.001, and r = 0.79, p<0.01, in 2006 and 2007) and indicated that all supply events were comprised of larvae that had been retained within the inner shelf; larvae transported to the outer shelf and beyond never recruited. Estimated average dispersal distances ranged from 57 to 198 km and were only marginally affected by mortality. Conclusions/Significance The high degree of predicted demographic connectivity over relatively large geographic scales is consistent with the lack of genetic structuring in C. maenas along the Iberian Peninsula. These findings indicate that the dynamic nature of larval dispersal can be captured by mechanistic biophysical models, which can be used to provide meaningful predictions of the patterns and causes of fine-scale variability in larval supply to marine populations. PMID:22558225

  19. Specific Genetic Disorders

    MedlinePlus

    ... of Genetic Terms Definitions for genetic terms Specific Genetic Disorders Many human diseases have a genetic component. ... Condition in an Adult The Undiagnosed Diseases Program Genetic Disorders Achondroplasia Alpha-1 Antitrypsin Deficiency Antiphospholipid Syndrome ...

  20. Phenotypic evolution in a poorly dispersing snail after arrival of a predator

    NASA Astrophysics Data System (ADS)

    Vermeij, Geerat J.

    1982-09-01

    The phenotypic stability of many species in the face of changing conditions suggests that adaptive evolution can occur only under limited circumstances. One of the necessary conditions may be the lack of genetic mixing between dispersed populations inhabiting different environments. Intertidal molluscs on the east coast of North America between Cape Cod and Nova Scotia were exposed to an increase in the abundance of shell breaking predators when the green crab Carcinus maenas spread gradually northward from Cape Cod in the first half of the twentieth century1. The periwinkle Littorina littorea, which produces larvae that become widely dispersed, did not show an increase in shell thickness as an adaptation to shell-breaking predation1. However, I show here that the dog whelk Nucella lapillus, which is poorly dispersed in the bottom-dwelling juvenile phase, did adapt phenotypically after establishment of the green crab. This suggests that phenotypic stasis and gradual change are alternative responses depending on the degree of genetic mixing between populations.

  1. Genetic haemochromatosis.

    PubMed

    Rosalki, S B

    2002-10-01

    Genetic haemochromatosis is an autosomal recessive inherited disorder of iron metabolism due to mutation of the HFE gene. In homozygotes (1 in 300 of the UK population), this results in excessive iron absorption from the gut and its deposition in major body organs. This may give rise to fatigue, arthritis, cardiac failure, diabetes mellitus, hepatic cirrhosis or skin pigmentation, occurring predominantly in males over 50 years of age. Identification uses measurement of serum iron, iron-binding capacity (or transferrin) and ferritin, together with initial or confirmatory genetic DNA studies.

  2. Genetic Disorders

    MedlinePlus

    ... of pregnancy loss. How do I know which tests to have? Your health care provider or a genetic counselor can discuss all of the testing options with you and help you decide based on your individual risk factors. Do I have to have these tests? Whether you want to be tested is a ...

  3. Genetic Recombination

    ERIC Educational Resources Information Center

    Whitehouse, H. L. K.

    1973-01-01

    Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)

  4. Cancer Genetics Services Directory

    MedlinePlus

    ... Overview–for health professionals Research NCI Cancer Genetics Services Directory This directory lists professionals who provide services related to cancer genetics (cancer risk assessment, genetic ...

  5. Genetic testing, genetic medicine, and managed care.

    PubMed

    Rothstein, M A; Hoffman, S

    1999-01-01

    As modern human genetics moves from the research setting to the clinical setting, it will encounter the managed care system. Issues of cost, access, and quality of care will affect the availability and nature of genetic testing, genetic counseling, and genetic therapies. This Article will explore such issues as professional education, coverage of genetic services, privacy and confidentiality, and liability. It will conclude with a series of recommendations for the practice of genetic medicine in the age of managed care.

  6. Human genetics

    SciTech Connect

    Carlson, E.A.

    1984-01-01

    This text provides full and balanced coverage of the concepts requisite for a thorough understanding of human genetics. Applications to both the individual and society are integrated throughout the lively and personal narrative, and the essential principles of heredity are clearly presented to prepare students for informed participation in public controversies. High-interest, controversial topics, including recombinant DNA technology, oncogenes, embryo transfer, environmental mutagens and carcinogens, IQ testing, and eugenics encourage understanding of important social issues.

  7. Mitochondrial genetics

    PubMed Central

    Chinnery, Patrick Francis; Hudson, Gavin

    2013-01-01

    Introduction In the last 10 years the field of mitochondrial genetics has widened, shifting the focus from rare sporadic, metabolic disease to the effects of mitochondrial DNA (mtDNA) variation in a growing spectrum of human disease. The aim of this review is to guide the reader through some key concepts regarding mitochondria before introducing both classic and emerging mitochondrial disorders. Sources of data In this article, a review of the current mitochondrial genetics literature was conducted using PubMed (http://www.ncbi.nlm.nih.gov/pubmed/). In addition, this review makes use of a growing number of publically available databases including MITOMAP, a human mitochondrial genome database (www.mitomap.org), the Human DNA polymerase Gamma Mutation Database (http://tools.niehs.nih.gov/polg/) and PhyloTree.org (www.phylotree.org), a repository of global mtDNA variation. Areas of agreement The disruption in cellular energy, resulting from defects in mtDNA or defects in the nuclear-encoded genes responsible for mitochondrial maintenance, manifests in a growing number of human diseases. Areas of controversy The exact mechanisms which govern the inheritance of mtDNA are hotly debated. Growing points Although still in the early stages, the development of in vitro genetic manipulation could see an end to the inheritance of the most severe mtDNA disease. PMID:23704099

  8. Genetic Testing (For Parents)

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Genetic Testing KidsHealth > For Parents > Genetic Testing Print A ... blood, skin, bone, or other tissue is needed. Genetic Testing During Pregnancy For genetic testing before birth, ...

  9. Cancer Genetics Services Directory

    MedlinePlus

    ... Services Directory Cancer Prevention Overview Research NCI Cancer Genetics Services Directory This directory lists professionals who provide services related to cancer genetics (cancer risk assessment, genetic counseling, genetic susceptibility testing, ...

  10. Genetic toxicology.

    PubMed

    Kramer, P J

    1998-04-01

    Systems for testing genetic toxicology are components of carcinogenic and genetic risk assessment. Present routine genotoxicity-testing is based on at least 20 years of development during which many different test systems have been introduced and used. Today, it is clear that no single test is capable of detecting all genotoxic agents. Therefore, the usual approach is to perform a standard battery of in-vitro and in-vivo tests for genotoxicity. Work-groups of the European Union (EU), the Organization for Economic Co-operation and Development (OECD), and, very recently, the work-group of the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) have defined such standard battery tests. These and some currently used supplementary or confirmatory tests are briefly discussed here. Additional test systems for the assessment of genotoxic and carcinogenic hazard and risk are seriously needed. These tests must be more relevant to man than are current assays and less demanding in respect of cost, time and number of animals. Another aspect for reassessment derives from the actual situation in the pharmaceutical industry. Companies have to prepare for the world economy of the 21st century. Therefore, pharmaceutical research is speeding up tremendously by use of tools such as genomics, combinatorial chemistry, high throughput screening and proteomics. Toxicology and genotoxicology need to re-evaluate their changing environment and must find ways to respond to these needs. In conclusion, genetic toxicology needs to answer questions coming from two major directions: hazard and risk identification and high throughput testing. PMID:9625484

  11. Inhibition between invasives: a newly introduced predator moderates the impacts of a previously established invasive predator.

    PubMed

    Griffen, Blaine D; Guy, Travis; Buck, Julia C

    2008-01-01

    1. With continued globalization, species are being transported and introduced into novel habitats at an accelerating rate. Interactions between invasive species may provide important mechanisms that moderate their impacts on native species. 2. The European green crab Carcinus maenas is an aggressive predator that was introduced to the east coast of North America in the mid-1800 s and is capable of rapid consumption of bivalve prey. A newer invasive predator, the Asian shore crab Hemigrapsus sanguineus, was first discovered on the Atlantic coast in the 1980s, and now inhabits many of the same regions as C. maenas within the Gulf of Maine. Using a series of field and laboratory investigations, we examined the consequences of interactions between these predators. 3. Density patterns of these two species at different spatial scales are consistent with negative interactions. As a result of these interactions, C. maenas alters its diet to consume fewer mussels, its preferred prey, in the presence of H. sanguineus. Decreased mussel consumption in turn leads to lower growth rates for C. maenas, with potential detrimental effects on C. maenas populations. 4. Rather than an invasional meltdown, this study demonstrates that, within the Gulf of Maine, this new invasive predator can moderate the impacts of the older invasive predator.

  12. Consumers that are not 'ideal' or 'free' can still approach the ideal free distribution using simple patch-leaving rules.

    PubMed

    Griffen, Blaine D

    2009-09-01

    1. The ideal free distribution (IFD) has been widely used to determine whether consumers distribute themselves optimally. However, this theory is based on three assumptions that are clearly violated in many systems. The theory assumes that all individuals know the quality of each available site, are equally free to move between all sites, and have equal competitive abilities. 2. I examine the utility of this theory to predict the distribution of the invasive European green crab Carcinus maenas, a species that likely violates all of these assumptions. I demonstrate three main findings. 3. First, understanding how density-dependent interference and size alter individual foraging behaviour is important for understanding the density and biomass distribution of C. maenas in invaded habitats. 4. Second, once behavioural mechanisms of crab foraging are accurately included in the model, the IFD does a good job of predicting the distribution of C. maenas, even though C. maenas violates the theory's fundamental assumptions. 5. Third, C. maenas' distribution can be obtained using simple decision rules and reasonable movement patterns. PMID:19486205

  13. Inhibition between invasives: a newly introduced predator moderates the impacts of a previously established invasive predator.

    PubMed

    Griffen, Blaine D; Guy, Travis; Buck, Julia C

    2008-01-01

    1. With continued globalization, species are being transported and introduced into novel habitats at an accelerating rate. Interactions between invasive species may provide important mechanisms that moderate their impacts on native species. 2. The European green crab Carcinus maenas is an aggressive predator that was introduced to the east coast of North America in the mid-1800 s and is capable of rapid consumption of bivalve prey. A newer invasive predator, the Asian shore crab Hemigrapsus sanguineus, was first discovered on the Atlantic coast in the 1980s, and now inhabits many of the same regions as C. maenas within the Gulf of Maine. Using a series of field and laboratory investigations, we examined the consequences of interactions between these predators. 3. Density patterns of these two species at different spatial scales are consistent with negative interactions. As a result of these interactions, C. maenas alters its diet to consume fewer mussels, its preferred prey, in the presence of H. sanguineus. Decreased mussel consumption in turn leads to lower growth rates for C. maenas, with potential detrimental effects on C. maenas populations. 4. Rather than an invasional meltdown, this study demonstrates that, within the Gulf of Maine, this new invasive predator can moderate the impacts of the older invasive predator. PMID:18177327

  14. Foraging by marine scavengers: Effects of relatedness, bait damage and hunger

    NASA Astrophysics Data System (ADS)

    Moore, P. G.; Howarth, J.

    1996-12-01

    Field studies using fish-baited creels have confirmed that Carcinus maenas, Necora puber and Pagurus bernhardus (Crustacea: Decapoda), Buccinum undatum (Gastropoda) and Asterias rubens (Echinodermata) are prominent scavenging species in shallow waters in the Clyde Sea area. Capture rates of these species by creels baited with dead fish plus variously damaged C. maenas were examined in the field. The addition of substantially fractured C. maenas significantly reduced the capture of conspecifics, but significantly enhanced the capture of the taxonomically unrelated species A. rubens. The remaining crustacean taxa (of the above) were unaffected by this treatment. The magnitude of th response was related strongly to the extent to which C. maenas were damaged. The effects of hunger on these responses were tested in a laboratory experiment in which the responses of starved and fed batches of C. maenas were investigated. Starved crabs remained attracted to fish bait, despite the proximity of dead conspecifics. Conversely, crabs of the fed batch were significantly more reluctant to enter creels containing damaged conspecifics. The localized presence of odours emanating from dead conspecifics did not cause crabs to remain inactive in shelter. We conclude that taxonomic relatedness to bait, degree of carcass damage and hunger of the scavenger all interact in determining foraging decision-making even by so-called generalist scavengers.

  15. Genetic Testing for ALS

    MedlinePlus

    ... Involved Donate Familial Amyotrophic Lateral Sclerosis (FALS) and Genetic Testing By Deborah Hartzfeld, MS, CGC, Certified Genetic ... guarantee a person will develop symptoms of ALS. Genetic Counseling If there is more than one person ...

  16. Jurisprudence and genetics.

    PubMed

    Kaveny, M C

    1999-03-01

    This section of the Notes in Moral Theology attempts to grapple with the proper relation of law and morality in three emerging issues connected with genetics: cloning, discrimination on the basis of genetic information, and patenting of genetic material.

  17. The genetics of immunity.

    PubMed

    Lazzaro, Brian P; Schneider, David S

    2014-06-17

    In this commentary, Brian P. Lazzaro and David S. Schneider examine the topic of the Genetics of Immunity as explored in this month's issues of GENETICS and G3: Genes|Genomes|Genetics. These inaugural articles are part of a joint Genetics of Immunity collection (ongoing) in the GSA journals.

  18. Interactive Genetics Tutorial Project.

    ERIC Educational Resources Information Center

    Wisconsin Univ., Madison. Dept. of Curriculum and Instruction.

    The Interactive Genetics Tutorial (IGT) project and the Intelligent Tutoring System for the IGT project named MENDEL supplement genetics instruction in biology courses by providing students with experience in designing, conducting, and evaluating genetics experiments. The MENDEL software is designed to: (1) simulate genetics experiments that…

  19. The Genetics of Immunity

    PubMed Central

    Lazzaro, Brian P.; Schneider, David S.

    2014-01-01

    In this commentary, Brian P. Lazzaro and David S. Schneider examine the topic of the Genetics of Immunity as explored in this month's issues of GENETICS and G3: Genes|Genomes|Genetics. These inaugural articles are part of a joint Genetics of Immunity collection (ongoing) in the GSA journals. PMID:24939182

  20. How Are Genetic Conditions Diagnosed?

    MedlinePlus

    ... Consultation How are genetic conditions diagnosed? How are genetic conditions diagnosed? A doctor may suspect a diagnosis ... and advocacy resources. For more information about diagnosing genetic conditions: Genetics Home Reference provides information about genetic ...

  1. Update: Biochemistry of Genetic Manipulation.

    ERIC Educational Resources Information Center

    Barker, G. R.

    1983-01-01

    Various topics on the biochemistry of genetic manipulation are discussed. These include genetic transformation and DNA; genetic expression; DNA replication, repair, and mutation; technology of genetic manipulation; and applications of genetic manipulation. Other techniques employed are also considered. (JN)

  2. Genetic engineering, medicine and medical genetics.

    PubMed

    Motulsky, A G

    1984-01-01

    The impact of DNA technology in the near future will be on the manufacture of biologic agents and reagents that will lead to improved therapy and diagnosis. The use of DNA technology for prenatal and preclinical diagnosis in genetic diseases is likely to affect management of genetic diseases considerably. New and old questions regarding selective abortion and the psychosocial impact of early diagnosis of late appearing diseases and of genetic susceptibilities are being raised. Somatic therapy with isolated genes to treat disease has not been achieved. True germinal genetic engineering is far off for humans but may find applications in animal agriculture.

  3. Phenotypic clines, plasticity, and morphological trade-offs in an intertidal snail.

    PubMed

    Trussell, G C

    2000-02-01

    the abundance of an invading crab predator (Carcinus maenas). Water temperatures averaged 6.8 degrees C warmer during the transplant experiment and C. maenas abundance is greater in the southern Gulf of Maine. Because both increased water temperature and crab effluent affect shell form in the same way, future experiments are needed to determine the relative importance of each. Nevertheless, it is clear that phenotypic plasticity has an important role in producing geographic variation in L. obtusata shell form. Moreover, the evolution of phenotypic plasticity in L. obtusata and other marine gastropods may be driven by architectural constraints imposed by shell form on body mass and growth. PMID:10937192

  4. Basic genetics for dermatologists.

    PubMed

    Kumaran, Muthu Sendhil; De, Dipankar

    2013-01-01

    During the past few decades, advances in the field of molecular genetics have enriched us in understanding the pathogenesis of diseases, their identification, and appropriate therapeutic interventions. In the last 20 years, genetic basis of more than 350 monogenic skin diseases have been elucidated and is counting. The widespread use of molecular genetics as a tool in diagnosis is not practiced routinely due to genetic heterogenicity, limited access and low sensitivity. In this review, we have presented the very basics of genetics so as to enable dermatologists to have working understanding of medical genetics.

  5. Physicians' Knowledge of Genetics and Genetic Tests.

    ERIC Educational Resources Information Center

    Hofman, Karen J.; And Others

    1993-01-01

    A survey of 1,140 primary care physicians and psychiatrists who graduated from medical school from 1950 through 1985 indicated that knowledge of genetics is increasing, especially among more recent graduates, but deficiencies remain. Need is seen for greater emphasis on genetics to reduce chance of physician error as more tests become available.…

  6. Genetics Home Reference: porphyria

    MedlinePlus

    ... of iron in the liver, alcohol consumption, smoking, hepatitis C or HIV infection, or certain hormones. Mutations in ... Diagnostic Tests Drug Therapy Surgery and Rehabilitation Genetic Counseling Palliative Care Related Information How are genetic conditions ...

  7. Genetic Brain Disorders

    MedlinePlus

    A genetic brain disorder is caused by a variation or a mutation in a gene. A variation is a different form ... mutation is a change in a gene. Genetic brain disorders affect the development and function of the ...

  8. Frontotemporal Dementia: Genetics

    MedlinePlus

    ... Calendar of Events Fundraising Events Conferences Press Releases Genetics of FTD After receiving a diagnosis of FTD ... that recent advances in science have brought the genetics of FTD into much better focus. In 2012, ...

  9. Genetics of Hearing Loss

    MedlinePlus

    ... in Latin America Information For... Media Policy Makers Genetics of Hearing Loss Language: English Español (Spanish) Recommend ... of hearing loss in babies is due to genetic causes. There are also a number of things ...

  10. Genetic Disease Foundation

    MedlinePlus

    ... Newly Diagnosed Patients There are over 6,000 genetic disorders that can be passed down through the ... mission to help prevent, manage and treat inherited genetic diseases. View our latest News Brief here . You ...

  11. Genetics Home Reference

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Genetics Home Reference Past Issues / Spring 2007 Table of ... of this page please turn Javascript on. The Genetics Home Reference (GHR) Web site — ghr.nlm.nih. ...

  12. Genetics Home Reference: adermatoglyphia

    MedlinePlus

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions adermatoglyphia adermatoglyphia Enable Javascript to ...

  13. Genetics Home Reference: retinoblastoma

    MedlinePlus

    ... Arias VE. Trilateral retinoblastoma. Pediatr Blood Cancer. 2007 Mar;48(3):306-10. Review. Citation on PubMed ... for genetic counseling. Am J Hum Genet. 1998 Mar;62(3):610-9. Citation on PubMed or ...

  14. The formation of menaquinone-4 (vitamin K) and its oxide in some marine invertebrates.

    PubMed Central

    Burt, V T; Bee, E; Pennock, J F

    1977-01-01

    Three echinoderms, a crustacean, a mollusc and a coelenterate were injected with either [2-14C]mevalonate and unlabelled menadione (2-methyl-1,4-naphthaquinone) or 2-[14C]methyl-1,4-naphthaquinone. In each case the label was incorporated into menaquinone-4.[2-14C]Mevalonate was incorporated into menaquinone-4 in the crab (Carcinus maenas) only in the presence of menadione, the organism presumably being unable to synthesize the naphthaquinone nucleus. The starfish Asterias rubens and C. maenas incorporated the label into a compound which was identified chromatographically as 2,3-epoxymenaquinone-4. The significance of menaquinone-4 and these animals is discussed. PMID:849285

  15. Behavioral genetics and taste

    PubMed Central

    Boughter, John D; Bachmanov, Alexander A

    2007-01-01

    This review focuses on behavioral genetic studies of sweet, umami, bitter and salt taste responses in mammals. Studies involving mouse inbred strain comparisons and genetic analyses, and their impact on elucidation of taste receptors and transduction mechanisms are discussed. Finally, the effect of genetic variation in taste responsiveness on complex traits such as drug intake is considered. Recent advances in development of genomic resources make behavioral genetics a powerful approach for understanding mechanisms of taste. PMID:17903279

  16. Genetics by the Numbers

    MedlinePlus

    ... Life Science > Genetics by the Numbers Inside Life Science View All Articles | Inside Life Science Home Page Genetics by the Numbers By Chelsea ... Genetics NIH's National DNA Day This Inside Life Science article also appears on LiveScience . Learn about related ...

  17. Statistics for Learning Genetics

    ERIC Educational Resources Information Center

    Charles, Abigail Sheena

    2012-01-01

    This study investigated the knowledge and skills that biology students may need to help them understand statistics/mathematics as it applies to genetics. The data are based on analyses of current representative genetics texts, practicing genetics professors' perspectives, and more directly, students' perceptions of, and performance in,…

  18. The Genetics of Personality.

    ERIC Educational Resources Information Center

    Holden, Constance

    1987-01-01

    Reports on the findings of several studies into the genetic similarities of twins. Focuses on the relationships between personality and behavioral genetics and argues that genetic similarity seems to be a better predictor than environmental factors. Discusses psychopathology, cognitive abilities, and personality. (TW)

  19. Phenylketonuria Genetic Screening Simulation

    ERIC Educational Resources Information Center

    Erickson, Patti

    2012-01-01

    After agreeing to host over 200 students on a daylong genetics field trip, the author needed an easy-to-prepare genetics experiment to accompany the DNA-necklace and gel-electrophoresis activities already planned. One of the student's mothers is a pediatric physician at the local hospital, and she suggested exploring genetic-disease screening…

  20. An invasive species facilitates the recovery of salt marsh ecosystems on Cape Cod.

    PubMed

    Bertness, Mark D; Coverdale, Tyler C

    2013-09-01

    With global increases in human impacts, invasive species have become a major threat to ecosystems worldwide. While they have been traditionally viewed as harmful, invasive species may facilitate the restoration of degraded ecosystems outside their native ranges. In New England (USA) overfishing has depleted salt marsh predators, allowing the herbivorous crab Sesarma reticulatum to denude hundreds of hectares of low marsh. Here, using multiple site surveys and field caging experiments, we show that the subsequent invasion of green crabs, Carcinus maenas, into heavily burrowed marshes partially reverses decades of cordgrass die-off. By consuming Sesarma, eliciting a nonlethal escape response, and evicting Sesarma from burrows, Carcinus reduces Sesarma herbivory and promotes cordgrass recovery. These results suggest that invasive species can contribute to restoring degraded ecosystems and underscores the potential for invasive species to return ecological functions lost to human impacts. PMID:24279265

  1. An invasive species facilitates the recovery of salt marsh ecosystems on Cape Cod.

    PubMed

    Bertness, Mark D; Coverdale, Tyler C

    2013-09-01

    With global increases in human impacts, invasive species have become a major threat to ecosystems worldwide. While they have been traditionally viewed as harmful, invasive species may facilitate the restoration of degraded ecosystems outside their native ranges. In New England (USA) overfishing has depleted salt marsh predators, allowing the herbivorous crab Sesarma reticulatum to denude hundreds of hectares of low marsh. Here, using multiple site surveys and field caging experiments, we show that the subsequent invasion of green crabs, Carcinus maenas, into heavily burrowed marshes partially reverses decades of cordgrass die-off. By consuming Sesarma, eliciting a nonlethal escape response, and evicting Sesarma from burrows, Carcinus reduces Sesarma herbivory and promotes cordgrass recovery. These results suggest that invasive species can contribute to restoring degraded ecosystems and underscores the potential for invasive species to return ecological functions lost to human impacts.

  2. Differential escape from parasites by two competing introduced crabs

    USGS Publications Warehouse

    Blakeslee, April M.; Keogh, Carolyn L.; Byers, James E.; Kuris, Armand M.; Lafferty, Kevin D.; Torchin, Mark E.

    2009-01-01

    Although introduced species often interact with one another in their novel communities, the role of parasites in these interactions remains less clear. We examined parasite richness and prevalence in 2 shorecrab species with different invasion histories and residency times in an introduced region where their distributions overlap broadly. On the northeastern coast of the USA, the Asian shorecrab Hemigrapsus sanguineus was discovered 20 yr ago, while the European green crab Carcinus maenas has been established for over 200 yr. We used literature and field surveys to evaluate parasitism in both crabs in their native and introduced ranges. We found only 1 parasite species infecting H. sanguineus on the US East Coast compared to 6 species in its native range, while C. maenas was host to 3 parasite species on the East Coast compared to 10 in its native range. The prevalence of parasite infection was also lower for both crabs in the introduced range compared to their native ranges; however, the difference was almost twice as much for H. sanguineus as for C. maenas. There are several explanations that could contribute to C. maenas' greater parasite diversity than that of H. sanguineus on the US East Coast, including differences in susceptibility, time since introduction, manner of introduction (vector), distance from native range, taxonomic isolation, and the potential for parasite identification bias. Our study underscores not just that non-native species lose parasites upon introduction, but that they may do so differentially, with ramifications for their direct interactions and with potential community-level influences.

  3. A role for haemolymph oxygen capacity in heat tolerance of eurythermal crabs.

    PubMed

    Giomi, Folco; Pörtner, Hans-Otto

    2013-01-01

    Heat tolerance in aquatic ectotherms is constrained by a mismatch, occurring at high temperatures, between oxygen delivery and demand which compromises the maintenance of aerobic scope. The present study analyses how the wide thermal tolerance range of an eurythermal model species, the green crab Carcinus maenas is supported and limited by its ability to sustain efficient oxygen transport to tissues. Similar to other eurytherms, C. maenas sustains naturally occurring acute warming events through the integrated response of circulatory and respiratory systems. The response of C. maenas to warming can be characterized by two phases. During initial warming, oxygen consumption and heart rate increase, while stroke volume and haemolymph oxygen partial pressure decrease. During further warming, dissolved oxygen levels in the venous compartment decrease below the threshold of full haemocyanin oxygen saturation. The progressive release of haemocyanin bound oxygen with further warming follows an exponential pattern, thereby saving energy in oxygen transport and causing an associated leveling off of metabolic rate. According to the concept of oxygen and capacity limited thermal tolerance (OCLTT), this indicates that the thermal tolerance window is widened by the increasing contribution of haemocyanin oxygen transport and associated energy savings in cardiocirculation. Haemocyanin bound oxygen sustains cardiac performance to cover the temperature range experienced by C. maenas in the field. To our knowledge this is the first study providing evidence of a relationship between thermal tolerance and blood (haemolymph) oxygen transport in a eurythermal invertebrate. PMID:23720633

  4. Differential snail predation by an exotic crab and the geography of shell-claw covariance in the Northwest Atlantic.

    PubMed

    Edgell, Timothy C; Rochette, Rémy

    2008-05-01

    Here we investigate if predation by the European green crab (Carcinus maenas) differs between two congeneric snails in the northwest Atlantic (Littorina littorea and L. obtusata), and ask if differential predation can help explain the geography of claw and shell forms among geographically separated populations. First, correlations between crusher-claw size and shell mass -- tested across a wide size range of animals -- were highly significant among populations of C. maenas and L. obtusata, whereas only a small number of significant correlations were found between C. maenas and L. littorea, and these were limited to the smaller size classes of snails and crabs. Moreover, among populations, L. obtusata shells were more frequently scarred than those of L. littorea, and L. obtusata were attacked and killed more frequently than L. littorea during field- and laboratory-predation experiments. Combined, results suggest L. obtusata is currently under greater selection by C. maenas than L. littorea for more crab-resistant shell forms. One possible explanation for these patterns is that L. littorea may have interacted with green crabs for centuries (in Europe) prior to their reintroduction to green crabs in America, thus predator-resistance may had already evolved. PMID:18298647

  5. A role for haemolymph oxygen capacity in heat tolerance of eurythermal crabs

    PubMed Central

    Giomi, Folco; Pörtner, Hans-Otto

    2013-01-01

    Heat tolerance in aquatic ectotherms is constrained by a mismatch, occurring at high temperatures, between oxygen delivery and demand which compromises the maintenance of aerobic scope. The present study analyses how the wide thermal tolerance range of an eurythermal model species, the green crab Carcinus maenas is supported and limited by its ability to sustain efficient oxygen transport to tissues. Similar to other eurytherms, C. maenas sustains naturally occurring acute warming events through the integrated response of circulatory and respiratory systems. The response of C. maenas to warming can be characterized by two phases. During initial warming, oxygen consumption and heart rate increase, while stroke volume and haemolymph oxygen partial pressure decrease. During further warming, dissolved oxygen levels in the venous compartment decrease below the threshold of full haemocyanin oxygen saturation. The progressive release of haemocyanin bound oxygen with further warming follows an exponential pattern, thereby saving energy in oxygen transport and causing an associated leveling off of metabolic rate. According to the concept of oxygen and capacity limited thermal tolerance (OCLTT), this indicates that the thermal tolerance window is widened by the increasing contribution of haemocyanin oxygen transport and associated energy savings in cardiocirculation. Haemocyanin bound oxygen sustains cardiac performance to cover the temperature range experienced by C. maenas in the field. To our knowledge this is the first study providing evidence of a relationship between thermal tolerance and blood (haemolymph) oxygen transport in a eurythermal invertebrate. PMID:23720633

  6. Differential snail predation by an exotic crab and the geography of shell-claw covariance in the Northwest Atlantic.

    PubMed

    Edgell, Timothy C; Rochette, Rémy

    2008-05-01

    Here we investigate if predation by the European green crab (Carcinus maenas) differs between two congeneric snails in the northwest Atlantic (Littorina littorea and L. obtusata), and ask if differential predation can help explain the geography of claw and shell forms among geographically separated populations. First, correlations between crusher-claw size and shell mass -- tested across a wide size range of animals -- were highly significant among populations of C. maenas and L. obtusata, whereas only a small number of significant correlations were found between C. maenas and L. littorea, and these were limited to the smaller size classes of snails and crabs. Moreover, among populations, L. obtusata shells were more frequently scarred than those of L. littorea, and L. obtusata were attacked and killed more frequently than L. littorea during field- and laboratory-predation experiments. Combined, results suggest L. obtusata is currently under greater selection by C. maenas than L. littorea for more crab-resistant shell forms. One possible explanation for these patterns is that L. littorea may have interacted with green crabs for centuries (in Europe) prior to their reintroduction to green crabs in America, thus predator-resistance may had already evolved.

  7. Feline Genetics: Clinical Applications and Genetic Testing

    PubMed Central

    Lyons, Leslie A.

    2010-01-01

    DNA testing for domestic cat diseases and appearance traits is a rapidly growing asset for veterinary medicine. Approximately thirty-three genes contain fifty mutations that cause feline health problems or alterations in the cat’s appearance. A variety of commercial laboratories can now perform cat genetic diagnostics, allowing both the veterinary clinician and the private owner to obtain DNA test results. DNA is easily obtained from a cat via a buccal swab using a standard cotton bud or cytological brush, allowing DNA samples to be easily sent to any laboratory in the world. The DNA test results identify carriers of the traits, predict the incidence of traits from breeding programs, and influence medical prognoses and treatments. An overall goal of identifying these genetic mutations is the correction of the defect via gene therapies and designer drug therapies. Thus, genetic testing is an effective preventative medicine and a potential ultimate cure. However, genetic diagnostic tests may still be novel for many veterinary practitioners and their application in the clinical setting needs to have the same scrutiny as any other diagnostic procedure. This article will review the genetic tests for the domestic cat, potential sources of error for genetic testing, and the pros and cons of DNA results in veterinary medicine. Highlighted are genetic tests specific to the individual cat, which are a part of the cat’s internal genome. PMID:21147473

  8. Feline genetics: clinical applications and genetic testing.

    PubMed

    Lyons, Leslie A

    2010-11-01

    DNA testing for domestic cat diseases and appearance traits is a rapidly growing asset for veterinary medicine. Approximately 33 genes contain 50 mutations that cause feline health problems or alterations in the cat's appearance. A variety of commercial laboratories can now perform cat genetic diagnostics, allowing both the veterinary clinician and the private owner to obtain DNA test results. DNA is easily obtained from a cat via a buccal swab with a standard cotton bud or cytological brush, allowing DNA samples to be easily sent to any laboratory in the world. The DNA test results identify carriers of the traits, predict the incidence of traits from breeding programs, and influence medical prognoses and treatments. An overall goal of identifying these genetic mutations is the correction of the defect via gene therapies and designer drug therapies. Thus, genetic testing is an effective preventative medicine and a potential ultimate cure. However, genetic diagnostic tests may still be novel for many veterinary practitioners and their application in the clinical setting needs to have the same scrutiny as any other diagnostic procedure. This article will review the genetic tests for the domestic cat, potential sources of error for genetic testing, and the pros and cons of DNA results in veterinary medicine. Highlighted are genetic tests specific to the individual cat, which are a part of the cat's internal genome.

  9. Profilicollis botulus (Van Cleave, 1916) from diving ducks and shore crabs of British Columbia.

    PubMed

    Ching, H L

    1989-02-01

    Adults of Profilicollis botulus were found in 6 species of diving ducks in British Columbia including 3 new hosts: common goldeneye, Bucephala clangula (L.); Barrow's goldeneye, B. islandica (Gmelin); and greater scaup, Aythya marila (L.). The identification of the species was verified by the examination of co-types and specimens from eider ducks, Somateria mollissima (L.), from Scotland and oldsquaw, Clangula hyemalis (L.), from New Brunswick. Cystacanths from the hairy shore crab, Hemigrapsus oregonensis (Dana), were similar in morphology to those from Carcinus maenas (L.) from Scotland. PMID:2918442

  10. The role of epibenthic crustacean predators in an estuarine food web

    NASA Astrophysics Data System (ADS)

    Raffaelli, D.; Conacher, A.; McLachlan, H.; Emes, C.

    1989-02-01

    Two field experiments were carried out on an estuarine intertidal mudflat, enclosing varying densities of the crustacean predators Carcinus maenas and Crangon crangon. Effects of predation on prey densities were few and limited to cages with abnormally high densities of crabs. In both experiments there were significant effects on the size structure of the amphipod Corophium volutator. The results are compared with those from other caging experiments and it is suggested that, where marked, predation effects have been recorded unnaturally high densities of predators were used.

  11. Divergent induced responses to an invasive predator in marine mussel populations.

    PubMed

    Freeman, Aaren S; Byers, James E

    2006-08-11

    Invasive species may precipitate evolutionary change in invaded communities. In southern New England (USA) the invasive Asian shore crab, Hemigrapsus sanguineus, preys on mussels (Mytlius edulis), but the crab has not yet invaded northern New England. We show that southern New England mussels express inducible shell thickening when exposed to waterborne cues from Hemigrapsus, whereas naïve northern mussel populations do not respond. Yet, both populations thicken their shells in response to a long-established crab, Carcinus maenas. Our findings are consistent with the rapid evolution of an inducible morphological response to Hemigrapsus within 15 years of its introduction. PMID:16902136

  12. Divergent induced responses to an invasive predator in marine mussel populations.

    PubMed

    Freeman, Aaren S; Byers, James E

    2006-08-11

    Invasive species may precipitate evolutionary change in invaded communities. In southern New England (USA) the invasive Asian shore crab, Hemigrapsus sanguineus, preys on mussels (Mytlius edulis), but the crab has not yet invaded northern New England. We show that southern New England mussels express inducible shell thickening when exposed to waterborne cues from Hemigrapsus, whereas naïve northern mussel populations do not respond. Yet, both populations thicken their shells in response to a long-established crab, Carcinus maenas. Our findings are consistent with the rapid evolution of an inducible morphological response to Hemigrapsus within 15 years of its introduction.

  13. How Is Genetic Testing Done?

    MedlinePlus

    ... Testing How is genetic testing done? How is genetic testing done? Once a person decides to proceed ... is called informed consent . For more information about genetic testing procedures: The Genetic Science Learning Center at ...

  14. Prenatal Genetic Counseling (For Parents)

    MedlinePlus

    ... 5 Things to Know About Zika & Pregnancy Prenatal Genetic Counseling KidsHealth > For Parents > Prenatal Genetic Counseling Print ... how can they help your family? What Is Genetic Counseling? Genetic counseling is the process of: evaluating ...

  15. Genetic technology: Promises and problems

    NASA Technical Reports Server (NTRS)

    Frankel, M. S.

    1975-01-01

    Issues concerning the use of genetic technology are discussed. Some areas discussed include treating genetic disease, prenatal diagnosis and selective abortion, screening for genetic disease, and genetic counseling. Policy issues stemming from these capabilities are considered.

  16. Quantitation of peptide hormone in single cultured secretory neurons of the crab, Cardisoma carnifex.

    PubMed

    Keller, R; Grau, S; Cooke, I M

    1995-09-01

    The content of crustacean hyperglycemic hormone (CHH) in single cultured neurons of the crab Cardisoma carnifex was determined by a sensitive enzyme-linked immunosorbent assay (ELISA), using purified CHH (1-50 pg) of the crab Carcinus maenas as standard. The somata were dissociated from the group of approximately 150 peptidergic neurons that form the X-organ--sinus gland neuroendocrine system. As previously reported, the neurons show immediate regenerative outgrowth in defined culture conditions, and develop, generally, into one of two morphological types: cells that produce broad, lamelliform growth cones (veils), and others that are characterized by branching of neurites. In this study, all but one of 64 veiling cells taken after various times in culture up to 12 days contained CHH. They could be readily categorized as having "high" (> 33 pg; mean 86 +/- 5, S.E., n = 47) or "low" (< or = 33 pg; mean 22 +/- 2.5; n = 17) Carcinus CHH equivalents. Thus, CHH is associated with neurons showing veiling outgrowth, but veiling neurons with low CHH form a distinct, but not morphologically distinguishable group. They may contain an isoform of CHH with limited cross-reactivity. In 24 branching neurons assayed, Carcinus CHH equivalents averaged 7.2 +/- 2 pg. This figure includes 14 neurons in which CHH was undetectable, and one that had 40 pg of Carcinus CHH equivalents. There was no significant change of the hormone content in cells of either type during 6 days of culturing.

  17. Genetic selection and conservation of genetic diversity*.

    PubMed

    Blackburn, H D

    2012-08-01

    For 100s of years, livestock producers have employed various types of selection to alter livestock populations. Current selection strategies are little different, except our technologies for selection have become more powerful. Genetic resources at the breed level have been in and out of favour over time. These resources are the raw materials used to manipulate populations, and therefore, they are critical to the past and future success of the livestock sector. With increasing ability to rapidly change genetic composition of livestock populations, the conservation of these genetic resources becomes more critical. Globally, awareness of the need to steward genetic resources has increased. A growing number of countries have embarked on large scale conservation efforts by using in situ, ex situ (gene banking), or both approaches. Gene banking efforts have substantially increased and data suggest that gene banks are successfully capturing genetic diversity for research or industry use. It is also noteworthy that both industry and the research community are utilizing gene bank holdings. As pressures grow to meet consumer demands and potential changes in production systems, the linkage between selection goals and genetic conservation will increase as a mechanism to facilitate continued livestock sector development. PMID:22827378

  18. Genetic selection and conservation of genetic diversity*.

    PubMed

    Blackburn, H D

    2012-08-01

    For 100s of years, livestock producers have employed various types of selection to alter livestock populations. Current selection strategies are little different, except our technologies for selection have become more powerful. Genetic resources at the breed level have been in and out of favour over time. These resources are the raw materials used to manipulate populations, and therefore, they are critical to the past and future success of the livestock sector. With increasing ability to rapidly change genetic composition of livestock populations, the conservation of these genetic resources becomes more critical. Globally, awareness of the need to steward genetic resources has increased. A growing number of countries have embarked on large scale conservation efforts by using in situ, ex situ (gene banking), or both approaches. Gene banking efforts have substantially increased and data suggest that gene banks are successfully capturing genetic diversity for research or industry use. It is also noteworthy that both industry and the research community are utilizing gene bank holdings. As pressures grow to meet consumer demands and potential changes in production systems, the linkage between selection goals and genetic conservation will increase as a mechanism to facilitate continued livestock sector development.

  19. Transcriptome sequencing reveals both neutral and adaptive genome dynamics in a marine invader.

    PubMed

    Tepolt, C K; Palumbi, S R

    2015-08-01

    Species invasions cause significant ecological and economic damage, and genetic information is important to understanding and managing invasive species. In the ocean, many invasive species have high dispersal and gene flow, lowering the discriminatory power of traditional genetic approaches. High-throughput sequencing holds tremendous promise for increasing resolution and illuminating the relative contributions of selection and drift in marine invasion, but has not yet been used to compare the diversity and dynamics of a high-dispersal invader in its native and invaded ranges. We test a transcriptome-based approach in the European green crab (Carcinus maenas), a widespread invasive species with high gene flow and a well-known invasion history, in two native and five invasive populations. A panel of 10 809 transcriptome-derived nuclear SNPs identified significant population structure among highly bottlenecked invasive populations that were previously undifferentiated with traditional markers. Comparing the full data set and a subset of 9246 putatively neutral SNPs strongly suggested that non-neutral processes are the primary driver of population structure within the species' native range, while neutral processes appear to dominate in the invaded range. Non-neutral native range structure coincides with significant differences in intraspecific thermal tolerance, suggesting temperature as a potential selective agent. These results underline the importance of adaptation in shaping intraspecific differences even in high geneflow marine invasive species. They also demonstrate that high-throughput approaches have broad utility in determining neutral structure in recent invasions of such species. Together, neutral and non-neutral data derived from high-throughput approaches may increase the understanding of invasion dynamics in high-dispersal species. PMID:26118396

  20. Transcriptome sequencing reveals both neutral and adaptive genome dynamics in a marine invader.

    PubMed

    Tepolt, C K; Palumbi, S R

    2015-08-01

    Species invasions cause significant ecological and economic damage, and genetic information is important to understanding and managing invasive species. In the ocean, many invasive species have high dispersal and gene flow, lowering the discriminatory power of traditional genetic approaches. High-throughput sequencing holds tremendous promise for increasing resolution and illuminating the relative contributions of selection and drift in marine invasion, but has not yet been used to compare the diversity and dynamics of a high-dispersal invader in its native and invaded ranges. We test a transcriptome-based approach in the European green crab (Carcinus maenas), a widespread invasive species with high gene flow and a well-known invasion history, in two native and five invasive populations. A panel of 10 809 transcriptome-derived nuclear SNPs identified significant population structure among highly bottlenecked invasive populations that were previously undifferentiated with traditional markers. Comparing the full data set and a subset of 9246 putatively neutral SNPs strongly suggested that non-neutral processes are the primary driver of population structure within the species' native range, while neutral processes appear to dominate in the invaded range. Non-neutral native range structure coincides with significant differences in intraspecific thermal tolerance, suggesting temperature as a potential selective agent. These results underline the importance of adaptation in shaping intraspecific differences even in high geneflow marine invasive species. They also demonstrate that high-throughput approaches have broad utility in determining neutral structure in recent invasions of such species. Together, neutral and non-neutral data derived from high-throughput approaches may increase the understanding of invasion dynamics in high-dispersal species.

  1. Genetics of the Connectome

    PubMed Central

    Thompson, Paul M.; Ge, Tian; Glahn, David C.; Jahanshad, Neda; Nichols, Thomas E.

    2014-01-01

    Connectome genetics attempts to discover how genetic factors affect brain connectivity. Here we review a variety of genetic analysis methods – such as genome-wide association studies (GWAS), linkage and candidate gene studies – that have been fruitfully adapted to imaging data to implicate specific variants in the genome for brain-related traits. We then review studies of that emphasized the genetic influences on brain connectivity. Some of these perform genetic analysis of brain integrity and connectivity using diffusion MRI, and others have mapped genetic effects on functional networks using resting state functional MRI. Connectome-wide genome-wide scans have also been conducted, and we review the multivariate methods required to handle the extremely high dimension of genomic and the network data. We also review some consortium efforts, such as ENIGMA, that offer the power to detect robust common genetic associations using phenotypic harmonization procedures and meta-analysis. Current work on connectome genetics is advancing on many fronts and promises to shed light on how disease risk genes affect the brain. It is already discovering new genetic loci and even entire genetic networks that affect brain organization and connectivity. PMID:23707675

  2. Wavelets meet genetic imaging

    NASA Astrophysics Data System (ADS)

    Wang, Yu-Ping

    2005-08-01

    Genetic image analysis is an interdisciplinary area, which combines microscope image processing techniques with the use of biochemical probes for the detection of genetic aberrations responsible for cancers and genetic diseases. Recent years have witnessed parallel and significant progress in both image processing and genetics. On one hand, revolutionary multiscale wavelet techniques have been developed in signal processing and applied mathematics in the last decade, providing sophisticated tools for genetic image analysis. On the other hand, reaping the fruit of genome sequencing, high resolution genetic probes have been developed to facilitate accurate detection of subtle and cryptic genetic aberrations. In the meantime, however, they bring about computational challenges for image analysis. In this paper, we review the fruitful interaction between wavelets and genetic imaging. We show how wavelets offer a perfect tool to address a variety of chromosome image analysis problems. In fact, the same word "subband" has been used in the nomenclature of cytogenetics to describe the multiresolution banding structure of the chromosome, even before its appearance in the wavelet literature. The application of wavelets to chromosome analysis holds great promise in addressing several computational challenges in genetics. A variety of real world examples such as the chromosome image enhancement, compression, registration and classification will be demonstrated. These examples are drawn from fluorescence in situ hybridization (FISH) and microarray (gene chip) imaging experiments, which indicate the impact of wavelets on the diagnosis, treatments and prognosis of cancers and genetic diseases.

  3. Genetic Variation and Atherosclerosis

    PubMed Central

    Biros, Erik; Karan, Mirko; Golledge, Jonathan

    2008-01-01

    A family history of atherosclerosis is independently associated with an increased incidence of cardiovascular events. The genetic factors underlying the importance of inheritance in atherosclerosis are starting to be understood. Genetic variation, such as mutations or common polymorphisms has been shown to be involved in modulation of a range of risk factors, such as plasma lipoprotein levels, inflammation and vascular calcification. This review presents examples of present studies of the role of genetic polymorphism in atherosclerosis. PMID:19424482

  4. Caging and Uncaging Genetics

    PubMed Central

    Little, Tom J.; Colegrave, Nick

    2016-01-01

    It is important for biology to understand if observations made in highly reductionist laboratory settings generalise to harsh and noisy natural environments in which genetic variation is sorted to produce adaptation. But what do we learn by studying, in the laboratory, a genetically diverse population that mirrors the wild? What is the best design for studying genetic variation? When should we consider it at all? The right experimental approach depends on what you want to know. PMID:27458971

  5. Genetic toxicology: web resources.

    PubMed

    Young, Robert R

    2002-04-25

    Genetic toxicology is the scientific discipline dealing with the effects of chemical, physical and biological agents on the heredity of living organisms. The Internet offers a wide range of online digital resources for the field of Genetic Toxicology. The history of genetic toxicology and electronic data collections are reviewed. Web-based resources at US National Library of Medicine (NLM), including MEDLINE, PUBMED, Gateway, Entrez, and TOXNET, are discussed. Search strategies and Medical Subject Headings (MeSH) are reviewed in the context of genetic toxicology. The TOXNET group of databases are discussed with emphasis on those databases with genetic toxicology content including GENE-TOX, TOXLINE, Hazardous Substances Data Bank, Integrated Risk Information System, and Chemical Carcinogenesis Research Information System. Location of chemical information including chemical structure and linkage to health and regulatory information using CHEMIDPLUS at NLM and other databases is reviewed. Various government agencies have active genetic toxicology research programs or use genetic toxicology data to assist fulfilling the agency's mission. Online resources at the US Food and Drug Administration (FDA), the US Environmental Protection Agency (EPA), the National Institutes of Environmental Health Sciences, and the National Toxicology Program (NTP) are outlined. Much of the genetic toxicology for pharmaceuticals, industrial chemicals and pesticides that is performed in the world is regulatory-driven. Regulatory web resources are presented for the laws mandating testing, guidelines on study design, Good Laboratory Practice (GLP) regulations, and requirements for electronic data collection and reporting. The Internet provides a range of other supporting resources to the field of genetic toxicology. The web links for key professional societies and journals in genetic toxicology are listed. Distance education, educational media resources, and job placement services are also

  6. Genetics of Sarcoidosis.

    PubMed

    Fingerlin, Tasha E; Hamzeh, Nabeel; Maier, Lisa A

    2015-12-01

    Sarcoidosis is a disease with highly variable presentation and progression; although it is hypothesized that disease phenotype is related to genetic variation, how much of this variability is driven by genetic factors is not known. The HLA region is the most strongly and consistently associated genetic risk factor for sarcoidosis, supporting the notion that sarcoidosis is an exposure-mediated immunologic disease. Most of the genetic etiology of sarcoidosis remains unknown in terms of the specific variants that increase risk in various populations, their biologic functions, and how they interact with environmental exposures.

  7. Engineering genetic injustice.

    PubMed

    Wenz, Peter

    2005-02-01

    In their jointly written book, From Chance to Choice: Genetics and Justice, Allen Buchanan, Dan Brock, Norman Daniels and Daniel Wikler defend 'the development and deployment of genetic intervention technologies..', including genetic enhancements, against charges that they exacerbate injustice. The present paper examines some of their arguments. The first section shows that the authors confuse real societies with just societies. The second shows that without this confusion, their arguments reveal the enormous justice-impairing potential of deploying genetic enhancements in such societies as the United States.

  8. Genetics, society, and decisions

    SciTech Connect

    Kowles, R.V.

    1985-01-01

    This book provides a conceptual understanding of the biology of genes and also gives current events and controversies in the field. Basic transmission genetics, molecular genetics, and population genetics are covered, with additional discussions relating to such topics as agriculture, aging, forensic science, genetic counseling, gene splicing, and recombinant DNA. Low level radiation and its effects, drugs and heredity, IQ, heredity and racial variation, and creationism versus evolution are also described. ''Billboard'' style diagrams visually explain important concepts. Boldfaced key terms are defined within the text and in a comprehensive glossary. Selected readings, discussion questions and problems, and excellent chapter summaries further aid study.

  9. Judaism, genetic screening and genetic therapy.

    PubMed

    Rosner, F

    1998-01-01

    Genetic screening, gene therapy and other applications of genetic engineering are permissible in Judaism when used for the treatment, cure, or prevention of disease. Such genetic manipulation is not considered to be a violation of God's natural law, but a legitimate implementation of the biblical mandate to heal. If Tay-Sachs disease, diabetes, hemophilia, cystic fibrosis, Huntington's disease or other genetic diseases can be cured or prevented by "gene surgery," then it is certainly permitted in Jewish law. Genetic premarital screening is encouraged in Judaism for the purpose of discouraging at-risk marriages for a fatal illness such as Tay-Sachs disease. Neonatal screening for treatable conditions such as phenylketonuria is certainly desirable and perhaps required in Jewish law. Preimplantation screening and the implantation of only "healthy" zygotes into the mother's womb to prevent the birth of an affected child are probably sanctioned in Jewish law. Whether or not these assisted reproduction techniques may be used to choose the sex of one's offspring, to prevent the birth of a child with a sex-linked disease such as hemophilia, has not yet been ruled on by modern rabbinic decisions. Prenatal screening with the specific intent of aborting an affected fetus is not allowed according to most rabbinic authorities, although a minority view permits it "for great need." Not to have children if both parents are carriers of genetic diseases such as Tay-Sachs is not a Jewish option. Preimplantation screening is preferable. All screening test results must remain confidential. Judaism does not permit the alteration or manipulation of physical traits and characteristics such as height, eye and hair color, facial features and the like, when such change provides no useful benefit to mankind. On the other hand, it is permissible to clone organisms and microorganisms to facilitate the production of insulin, growth hormone, and other agents intended to benefit mankind and to

  10. Ethical issues in genetics.

    PubMed

    Shannon, T A

    1999-03-01

    The first section of the Notes on Moral Theology reviews ethical issues in genetics through the lenses of privacy-confidentiality; risk-benefit analysis in relation to prenatal diagnosis and gene therapy; and freedom-determinism/human dignity in the context of cloning. The author provides an overview of developments in genetics and highlights thematic issues common to these developments.

  11. Genetics of aging bone.

    PubMed

    Adams, Douglas J; Rowe, David W; Ackert-Bicknell, Cheryl L

    2016-08-01

    With aging, the skeleton experiences a number of changes, which include reductions in mass and changes in matrix composition, leading to fragility and ultimately an increase of fracture risk. A number of aspects of bone physiology are controlled by genetic factors, including peak bone mass, bone shape, and composition; however, forward genetic studies in humans have largely concentrated on clinically available measures such as bone mineral density (BMD). Forward genetic studies in rodents have also heavily focused on BMD; however, investigations of direct measures of bone strength, size, and shape have also been conducted. Overwhelmingly, these studies of the genetics of bone strength have identified loci that modulate strength via influencing bone size, and may not impact the matrix material properties of bone. Many of the rodent forward genetic studies lacked sufficient mapping resolution for candidate gene identification; however, newer studies using genetic mapping populations such as Advanced Intercrosses and the Collaborative Cross appear to have overcome this issue and show promise for future studies. The majority of the genetic mapping studies conducted to date have focused on younger animals and thus an understanding of the genetic control of age-related bone loss represents a key gap in knowledge.

  12. PopGenetics.

    ERIC Educational Resources Information Center

    Johnson, David A.

    1995-01-01

    Describes new software called "PopGenetics" that is useful for conducting hands-on laboratory activities that illustrate population genetics. Users investigate the effects of selection and random drift on changes in allelic frequencies, the effect of mutation, and interactions among these three parameters. Designed for use on Macintosh computers.…

  13. Genetics and Developmental Psychology

    ERIC Educational Resources Information Center

    Plomin, Robert

    2004-01-01

    One of the major changes in developmental psychology during the past 50 years has been the acceptance of the important role of nature (genetics) as well as nurture (environment). Past research consisting of twin and adoption studies has shown that genetic influence is substantial for most domains of developmental psychology. Present research…

  14. Quo Vadis, Medical Genetics?

    NASA Astrophysics Data System (ADS)

    Czeizel, Andrew E.

    The beginning of human genetics and its medical part: medical genetics was promising in the early decades of this century. Many genetic diseases and defects with Mendelian origin were identified and it helped families with significant genetic burden to limit their child number. Unfortunately this good start was shadowed by two tragic events. On the one hand, in the 1930s and early 1940s the German fascism brought about the dominance of an unscientific eugenics to mask vile political crimes. People with genetic diseases-defects were forced to sterilisation and several of them were killed. On the other hand, in the 1950s lysenkoism inhibitied the evolution of genetics in the Soviet Union and their satelite countries. Lysenko's doctrine declared genetics as a product of imperialism and a guilty science, therefore leading geneticists were ousted form their posts and some of them were executed or put in prison. Past decades genetics has resulted fantastic new results and achieved a leading position within the natural sciences. To my mind, however, the expected wider use of new eugenics indicates a new tragedy and this Cassandra's prediction is the topic of this presentation.

  15. Genetics in the courts

    SciTech Connect

    Coyle, Heather; Drell, Dan

    2000-12-01

    Various: (1)TriState 2000 Genetics in the Courts (2) Growing impact of the new genetics on the courts (3)Human testing (4) Legal analysis - in re G.C. (5) Legal analysis - GM ''peanots'', and (6) Legal analysis for State vs Miller

  16. Cryptic Genetic Variation in Evolutionary Developmental Genetics

    PubMed Central

    Paaby, Annalise B.; Gibson, Greg

    2016-01-01

    Evolutionary developmental genetics has traditionally been conducted by two groups: Molecular evolutionists who emphasize divergence between species or higher taxa, and quantitative geneticists who study variation within species. Neither approach really comes to grips with the complexities of evolutionary transitions, particularly in light of the realization from genome-wide association studies that most complex traits fit an infinitesimal architecture, being influenced by thousands of loci. This paper discusses robustness, plasticity and lability, phenomena that we argue potentiate major evolutionary changes and provide a bridge between the conceptual treatments of macro- and micro-evolution. We offer cryptic genetic variation and conditional neutrality as mechanisms by which standing genetic variation can lead to developmental system drift and, sheltered within canalized processes, may facilitate developmental transitions and the evolution of novelty. Synthesis of the two dominant perspectives will require recognition that adaptation, divergence, drift and stability all depend on similar underlying quantitative genetic processes—processes that cannot be fully observed in continuously varying visible traits. PMID:27304973

  17. Genetic Influences on Learning Disabilties I: Clinical Genetics.

    ERIC Educational Resources Information Center

    Smith, Shelley D.; Pennington, Bruce F.

    1983-01-01

    A discussion of basic genetic principles is followed by a review of selected genetic syndromes involving learning disabilites (such as Noonan Syndrome, Neurofibromatosis, Pheuylketonuria, and cleft lip and palate). Guidelines for securing a genetic evaluation are given. (CL)

  18. Evolutionary behavioral genetics

    PubMed Central

    Zietsch, Brendan P.; de Candia, Teresa R; Keller, Matthew C.

    2014-01-01

    We describe the scientific enterprise at the intersection of evolutionary psychology and behavioral genetics—a field that could be termed Evolutionary Behavioral Genetics—and how modern genetic data is revolutionizing our ability to test questions in this field. We first explain how genetically informative data and designs can be used to investigate questions about the evolution of human behavior, and describe some of the findings arising from these approaches. Second, we explain how evolutionary theory can be applied to the investigation of behavioral genetic variation. We give examples of how new data and methods provide insight into the genetic architecture of behavioral variation and what this tells us about the evolutionary processes that acted on the underlying causal genetic variants. PMID:25587556

  19. [Genetics of endogenous psychoses].

    PubMed

    Zerbin-Rüdin, E

    1979-01-01

    As the endogeneous psychoses do not show a Mendelian mode of inheritance, empirical risk figures have to be calculated. They are heterogeneous and nurture as well as nature have a share in the manifestation of illness. The genetic basis of the schizophrenias is demonstrated by twin and adoption studies. The concordance rate in monozygotic twins is four times the rate in dizygotic twins. Schizophrenia is to be found in the biological families of schizophrenic adoptees but not in the adoptive families. However, despite their genetic identity, monozygotic twins do not show 100% concordance but 60% only. Nongenetic factors must be considered. Obviously they are nonspecific and vary between individuals. The same principles apply to the affective psychoses. At present research is most interested in the problem of heterogeneity. Do pure depressive and manic-depressive disease form one genetic entity, or two different ones, or have they in common part of their genetic basis? Some remarks on genetic counselling are made.

  20. Genetic variation and its maintenance

    SciTech Connect

    Roberts, D.F.; De Stefano, G.F.

    1986-01-01

    This book contains several papers divided among three sections. The section titles are: Genetic Diversity--Its Dimensions; Genetic Diversity--Its Origin and Maintenance; and Genetic Diversity--Applications and Problems of Complex Characters.

  1. Genetics, Disease Prevention and Treatment

    MedlinePlus

    ... for the genetic terms used on this page Genetics, Disease Prevention and Treatment Overview How can learning ... gov] Top of page How can knowing about genetics help treat disease? Every year, more than two ...

  2. National Society of Genetic Counselors

    MedlinePlus

    ... us: About NSGC About NSGC Join NSGC About Genetic Counselors NSGC in the News NSGC Leadership In ... Opportunities AEC Sponsors Healthcare Providers How can a genetic counselor help my practice? Genetic counselors can help ...

  3. Genetics of population isolates.

    PubMed

    Arcos-Burgos, M; Muenke, M

    2002-04-01

    Genetic isolates, as shown empirically by the Finnish, Old Order Amish, Hutterites, Sardinian and Jewish communities among others, represent a most important and powerful tool in genetically mapping inherited disorders. The main features associated with that genetic power are the existence of multigenerational pedigrees which are mostly descended from a small number of founders a short number of generations ago, environmental and phenotypic homogeneity, restricted geographical distribution, the presence of exhaustive and detailed records correlating individuals in very well ascertained pedigrees, and inbreeding as a norm. On the other hand, the presence of a multifounder effect or admixture among divergent populations in the founder time (e.g. the Finnish and the Paisa community from Colombia) will theoretically result in increased linkage disequilibrium among adjacent loci. The present review evaluates the historical context and features of some genetic isolates with emphasis on the basic population genetic concepts of inbreeding and genetic drift, and also the state-of-the-art in mapping traits, both Mendelian and complex, on genetic isolates. PMID:12030885

  4. Possible causes for growth variability and summer growth reduction in juvenile plaice Pleuronectes platessa L. in the western Dutch Wadden Sea

    NASA Astrophysics Data System (ADS)

    van der Veer, Henk W.; Jung, Alexa Sarina; Freitas, Vânia; Philippart, Catharina J. M.; Witte, Johannes IJ.

    2016-05-01

    Growth variability within individuals and among groups and locations and the phenomenon of summer growth reduction has been described for juvenile flatfish in a variety of European coastal areas whereby the underlying causes still remain elusive. Potential mechanisms were tested for juvenile plaice Pleuronectes platessa L. in the western Dutch Wadden Sea, by analysing published and unpublished information from long-term investigations (1986-present). Growth variability did occur and could be explained by differences induced by environmental variability (water temperature), and by non-genetic irreversible adaptation and sex. Dynamic Energy Budget analysis indicated that especially sexually-dimorphic growth in combination with variability in sex ratio could explain most of the variability in growth and the increase in the range of the size of individuals within the population over time. Summer growth reduction was not only observed among 0-group plaice in the intertidal, but also in the subtidal and tidal gullies as well as among I- and II-group plaice. Intraspecific competition for food was not detected but some support for interspecific competition with other predators was found. Also resource competition (due to crowding) with the other abundant epibenthic species (0-, I- and II-group flounder Platichthys flesus; the brown shrimp Crangon crangon; the shore crab Carcinus maenas; the goby species Pomatoschistus minutus and Pomatoschistus microps) could not explain the summer growth reduction. The observed growth reduction coincided with a decrease in stomach content, especially of regenerating body parts of benthic prey items. It is hypothesised that macrozoobenthos becomes less active after the spring phytoplankton bloom, reducing prey availability for juvenile plaice in summer, causing a reduction in food intake and hence in growth.

  5. Genetic autonomic disorders.

    PubMed

    Axelrod, Felicia B

    2013-03-01

    Genetic disorders affecting the autonomic nervous system can result in abnormal development of the nervous system or they can be caused by neurotransmitter imbalance, an ion-channel disturbance or by storage of deleterious material. The symptoms indicating autonomic dysfunction, however, will depend upon whether the genetic lesion has disrupted peripheral or central autonomic centers or both. Because the autonomic nervous system is pervasive and affects every organ system in the body, autonomic dysfunction will result in impaired homeostasis and symptoms will vary. The possibility of genetic confirmation by molecular testing for specific diagnosis is increasing but treatments tend to remain only supportive and directed toward particular symptoms. PMID:23465768

  6. Genetics of Obesity.

    PubMed

    Srivastava, Apurva; Srivastava, Neena; Mittal, Balraj

    2016-10-01

    Numerous classical genetic studies have proved that genes are contributory factors for obesity. Genes are directly responsible for obesity associated disorders such as Bardet-Biedl and Prader-Willi syndromes. However, both genes as well as environment are associated with obesity in the general population. Genetic epidemiological approaches, particularly genome-wide association studies, have unraveled many genes which play important roles in human obesity. Elucidation of their biological functions can be very useful for understanding pathobiology of obesity. In the near future, further exploration of obesity genetics may help to develop useful diagnostic and predictive tests for obesity treatment. PMID:27605733

  7. Welcome to Neurology: Genetics.

    PubMed

    Pulst, Stefan M

    2015-06-01

    The powers of human genetics and genetic technologies have transformed the complexities of neurology and neuroscience at the basic, translational, and now also the clinical level. We have left an era of black and white views of causative genetic variation and are entering a period of more than 50 shades of grey, fascinated with DNA variants that increase or decrease risk, epigenetic modification, and an unexpectedly large number of variants of unknown or potentially pathogenic significance. Loss-of-function alleles and even complete human gene knockouts for certain genes appear to be compatible with a normal phenotype. PMID:27066541

  8. Genetic Stroke Syndromes

    PubMed Central

    Barrett, Kevin M.; Meschia, James F.

    2014-01-01

    Purpose of Review: This review describes the clinical and radiographic features, genetic determinants, and treatment options for the most well-characterized monogenic disorders associated with stroke. Recent Findings: Stroke is a phenotype of many clinically important inherited disorders. Recognition of the clinical manifestations of genetic disorders associated with stroke is important for accurate diagnosis and prognosis. Genetic studies have led to the discovery of specific mutations associated with the clinical phenotypes of many inherited stroke syndromes. Summary: Several inherited causes of stroke have established and effective therapies, further underscoring the importance of timely diagnosis. PMID:24699489

  9. Genetics of Male Infertility.

    PubMed

    Neto, Filipe Tenorio Lira; Bach, Phil Vu; Najari, Bobby Baback; Li, Philip Shihua; Goldstein, Marc

    2016-10-01

    While 7 % of the men are infertile, currently, a genetic etiology is identified in less than 25 % of those men, and 30 % of the infertile men lack a definitive diagnosis, falling in the "idiopathic infertility" category. Advances in genetics and epigenetics have led to several proposed mechanisms for male infertility. These advances may result in new diagnostic tools, treatment approaches, and better counseling with regard to treatment options and prognosis. In this review, we focus on clinical aspects of male infertility and the role of genetics in elucidating etiologies and the potential of treatments. PMID:27502429

  10. Ethics and genetic testing.

    PubMed

    Grady, C

    1999-01-01

    The tremendous growth in knowledge about genes and genetic technologies will eventually enable us to know individual genotypes and susceptibilities to disease, perhaps even before birth. Each new genetic test developed raises serious issues for individuals and society on the circumstances under which genetic information should be sought and the uses that should be made of such information. Ethical reflection and analysis will help us to prepare for the responsible use of information about genotypes so that individuals, both now and in the future, are benefited and not harmed, so that justice is served, and so that confidentiality and privacy, and respect for the autonomy, dignity, and differences of each individual, are preserved.

  11. Genetically Engineered Cyanobacteria

    NASA Technical Reports Server (NTRS)

    Zhou, Ruanbao (Inventor); Gibbons, William (Inventor)

    2015-01-01

    The disclosed embodiments provide cyanobacteria spp. that have been genetically engineered to have increased production of carbon-based products of interest. These genetically engineered hosts efficiently convert carbon dioxide and light into carbon-based products of interest such as long chained hydrocarbons. Several constructs containing polynucleotides encoding enzymes active in the metabolic pathways of cyanobacteria are disclosed. In many instances, the cyanobacteria strains have been further genetically modified to optimize production of the carbon-based products of interest. The optimization includes both up-regulation and down-regulation of particular genes.

  12. Genetics Home Reference: Turner syndrome

    MedlinePlus

    ... pregnancies that do not survive to term (miscarriages and stillbirths). Related Information What information about a genetic condition can statistics provide? Why are some genetic conditions more common ...

  13. Genetics and Genetic Testing in Pancreatic Cancer.

    PubMed

    Whitcomb, David C; Shelton, Celeste A; Brand, Randall E

    2015-10-01

    Genetic testing of germline DNA is used in patients suspected of being at risk of pancreatic ductal adenocarcinoma (PDAC) to better define the individual's risk and to determine the mechanism of risk. A high genetic risk increases the pretest probability that a biomarker of early cancer is a true positive and warrants further investigation. The highest PDAC risk is generally associated with a hereditary predisposition. However, the majority of PDAC results from complex, progressive gene-environment interactions that currently fall outside the traditional risk models. Over many years, the combination of inflammation, exposure to DNA-damaging toxins, and failed DNA repair promote the accumulation of somatic mutations in pancreatic cells; PDAC risk is further increased by already present oncogenic germline mutations. Predictive models and new technologies are needed to classify patients into more accurate and mechanistic PDAC risk categories that can be linked to improved surveillance and preventative strategies.

  14. Genetic engineering of rotaviruses by reverse genetics.

    PubMed

    Komoto, Satoshi; Taniguchi, Koki

    2013-07-01

    The rotavirus genome is composed of 11 gene segments of dsRNA. A recent breakthrough in the field of rotaviruses is the development of a reverse genetics system for generating recombinant rotaviruses possessing a gene segment derived from cloned cDNA. Although this approach is a helper virus-driven system that is technically limited and gives low levels of recombinant viruses, it allows alteration of the rotavirus genome, thus contributing to our understanding of these medically important viruses. So far, this approach has successfully been applied to three of the 11 viral segments in our laboratory and others, and the efficiency of recovery of recombinant viruses has been improved. However, we are still waiting for the development of a helper virus-free reverse genetics system for generating an infectious rotavirus entirely from cDNAs, as has been achieved for other members of the Reoviridae family.

  15. Trading green backs for green crabs: evaluating the commercial shellfish harvest at risk from European green crab invasion

    PubMed Central

    Mach, Megan E; Chan, Kai MA

    2014-01-01

    Nonnative species pose a threat to native biodiversity and can have immense impacts on biological communities, altering the function of ecosystems. How much value is at risk from high-impact invasive species, and which parameters determine variation in that value, constitutes critical knowledge for directing both management and research, but it is rarely available. We evaluated the value of the commercial shellfish harvest that is at risk in nearshore ecosystems of Puget Sound, Washington State, USA, from the invasive European green crab, Carcinus maenas. We assessed this value using a simple static ecological model combined with an economic model using data from Puget Sound’s shellfish harvest and revenue and the relationship between C. maenas abundance and the consumption rate of shellfish. The model incorporates a range in C. maenas diet preference, calories consumed per year, and crab densities. C. maenas is likely to prey on commercially harvested hardshell clams, oysters, and mussels, which would likely reduce additional revenue from processing and distribution, and the number of jobs associated with these fisheries. The model results suggest possible revenue losses of these shellfish ranging from $1.03-23.8 million USD year -1 (2.8-64% losses), with additional processing and distribution losses up to $17.6 million USD and 442 job positions each year associated with a range of plausible parameter values. The broad range of values reflects the uncertainty in key factors underlying impacts, factors that are highly variable across invaded regions and so not knowable a priori. However, future research evaluating species invasions can reduce the uncertainty of impacts by characterizing several key parameters: density of individuals, number of arrivals, predation and competition interactions, and economic impacts. This study therefore provides direction for research to inform more accurate estimates of value-at-risk, and suggests substantial motivation for

  16. Trading green backs for green crabs: evaluating the commercial shellfish harvest at risk from European green crab invasion.

    PubMed

    Mach, Megan E; Chan, Kai Ma

    2013-01-01

    Nonnative species pose a threat to native biodiversity and can have immense impacts on biological communities, altering the function of ecosystems. How much value is at risk from high-impact invasive species, and which parameters determine variation in that value, constitutes critical knowledge for directing both management and research, but it is rarely available. We evaluated the value of the commercial shellfish harvest that is at risk in nearshore ecosystems of Puget Sound, Washington State, USA, from the invasive European green crab, Carcinus maenas. We assessed this value using a simple static ecological model combined with an economic model using data from Puget Sound's shellfish harvest and revenue and the relationship between C. maenas abundance and the consumption rate of shellfish. The model incorporates a range in C. maenas diet preference, calories consumed per year, and crab densities. C. maenas is likely to prey on commercially harvested hardshell clams, oysters, and mussels, which would likely reduce additional revenue from processing and distribution, and the number of jobs associated with these fisheries. The model results suggest possible revenue losses of these shellfish ranging from $1.03-23.8 million USD year (-1) (2.8-64% losses), with additional processing and distribution losses up to $17.6 million USD and 442 job positions each year associated with a range of plausible parameter values. The broad range of values reflects the uncertainty in key factors underlying impacts, factors that are highly variable across invaded regions and so not knowable a priori. However, future research evaluating species invasions can reduce the uncertainty of impacts by characterizing several key parameters: density of individuals, number of arrivals, predation and competition interactions, and economic impacts. This study therefore provides direction for research to inform more accurate estimates of value-at-risk, and suggests substantial motivation for

  17. Genetics of osteoarthritis.

    PubMed

    Rodriguez-Fontenla, Cristina; Gonzalez, Antonio

    2015-01-01

    Osteoarthritis (OA) is a complex disease caused by the interaction of multiple genetic and environmental factors. This review focuses on the studies that have contributed to the discovery of genetic susceptibility factors in OA. The most relevant associations discovered until now are discussed in detail: GDF-5, 7q22 locus, MCF2L, DOT1L, NCOA3 and also some important findings from the arcOGEN study. Moreover, the different approaches that can be used to minimize the specific problems of the study of OA genetics are discussed. These include the study of microsatellites, phenotype standardization and other methods such as meta-analysis of GWAS and gene-based analysis. It is expected that these new approaches contribute to finding new susceptibility genetic factors for OA.

  18. Genetics Home Reference: galactosialidosis

    MedlinePlus

    ... down sugar molecules (oligosaccharides) attached to certain proteins (glycoproteins) or fats (glycolipids). Cathepsin A is also found ... Inherited Metabolic Diseases ISMRD: The International Advocate for Glycoprotein Storage Diseases Genetic Testing Registry (1 link) Combined ...

  19. Transgenerational genetic effects.

    PubMed

    Nelson, Vicki R; Nadeau, Joseph H

    2010-12-01

    Since Mendel, studies of phenotypic variation and disease risk have emphasized associations between genotype and phenotype among affected individuals in families and populations. Although this paradigm has led to important insights into the molecular basis for many traits and diseases, most of the genetic variants that control the inheritance of these conditions continue to elude detection. Recent studies suggest an alternative mode of inheritance where genetic variants that are present in one generation affect phenotypes in subsequent generations, thereby decoupling the conventional relations between genotype and phenotype, and perhaps, contributing to 'missing heritability'. Under some conditions, these transgenerational genetic effects can be as frequent and strong as conventional inheritance, and can persist for multiple generations. Growing evidence suggests that RNA mediates these heritable epigenetic changes. The primary challenge now is to identify the molecular basis for these effects, characterize mechanisms and determine whether transgenerational genetic effects occur in humans.

  20. Genetics Home Reference: osteopetrosis

    MedlinePlus

    ... Open All Close All Description Osteopetrosis is a bone disease that makes bones abnormally dense and prone to ... Other Names for This Condition congenital osteopetrosis marble bone disease osteopetroses Related Information How are genetic conditions and ...

  1. The Genetics of Dementia

    PubMed Central

    Farlow, Janice L.; Foroud, Tatiana

    2014-01-01

    Over the past decade, there has been a dramatic evolution of genetic methodologies that can be used to identify genes contributing to disease. Initially, the focus was primarily on classical linkage analysis; more recently, genomewide association studies, and high-throughput whole genome and whole exome sequencing have provided efficient approaches to detect common and rare variation contributing to disease risk. Application of these methodologies to dementias has led to the nomination of dozens of causative and susceptibility genes, solidifying the recognition that genetic factors are important contributors to the disease processes. In this review, the authors focus on current knowledge of the genetics of Alzheimer's disease and frontotemporal lobar degeneration. A working understanding of the genes relevant to common dementias will become increasingly critical, as options for genetic testing and eventually gene-specific therapeutics are developed. PMID:24234360

  2. [Genetics of neuropathies].

    PubMed

    Gess, B; Schirmacher, A; Young, P

    2013-02-01

    Hereditary neuropathies belong to the most common neurogenetic disorders. They appear mostly as sensory and motor neuropathies but there are also pure sensory, pure motor as well as sensory and autonomic hereditary neuropathies. In clinical practice, knowledge of hereditary neuropathies is important in order to recognize them among polyneuropathies and achieve a successful genetic diagnosis. The molecular genetics of hereditary neuropathies are very heterogeneous with currently more than 40 known disease-causing genes. The 4 most common genes account for almost 90% of the genetically diagnosed hereditary neuropathies. In this review article we provide an overview of the currently known genes and propose a rational genetic work-up protocol of the most common genes.

  3. Genetics Home Reference: alkaptonuria

    MedlinePlus

    ... homogentisate oxidase. This enzyme helps break down the amino acids phenylalanine and tyrosine, which are important building blocks ... Resources MedlinePlus (2 links) Encyclopedia: Alkaptonuria Health Topic: Amino Acid Metabolism Disorders Genetic and Rare Diseases Information Center ( ...

  4. Genetics Home Reference: histidinemia

    MedlinePlus

    ... condition characterized by elevated blood levels of the amino acid histidine, a building block of most proteins. Histidinemia ... Additional Information & Resources MedlinePlus (2 links) Health Topic: Amino Acid Metabolism Disorders Health Topic: Newborn Screening Genetic and ...

  5. Genetics Home Reference: hyperlysinemia

    MedlinePlus

    ... condition characterized by elevated blood levels of the amino acid lysine, a building block of most proteins. Hyperlysinemia ... Additional Information & Resources MedlinePlus (2 links) Health Topic: Amino Acid Metabolism Disorders Health Topic: Newborn Screening Genetic and ...

  6. Genetics Home Reference: neuroblastoma

    MedlinePlus

    ... Help Me Understand Genetics Home Health Conditions neuroblastoma neuroblastoma Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Neuroblastoma is a type of cancer that most often ...

  7. Genetics Home Reference: acatalasemia

    MedlinePlus

    ... particular ethnic groups? Genetic Changes Mutations in the CAT gene can cause acatalasemia . This gene provides instructions ... DNA, proteins, and cell membranes. Mutations in the CAT gene greatly reduce the activity of catalase. A ...

  8. Annual review of genetics

    SciTech Connect

    Campbelll, A. . Aerosol Lab.)

    1988-01-01

    This book discusses the papers on genome organization in mammals. Various species mentioned are: cats; dogs; rodents; primates; chinese hamster, cows, horses, pigs, etc. Genetic mapping, biological evolution and DNA sequencing are briefly discussed.

  9. Genetics of Bone Density

    MedlinePlus

    ... study linked 32 novel genetic regions to bone mineral density. The findings may help researchers understand why ... or treating osteoporosis. Bones are made of a mineral and protein scaffold filled with bone cells. Bone ...

  10. Genetics Home Reference: macrozoospermia

    MedlinePlus

    ... leads to an inability to father biological children (infertility). In affected males, almost all sperm cells have ... Sperm Analysis Centers for Disease Control and Prevention: Infertility FAQs Genetic Testing Registry: Infertility associated with multi- ...

  11. Genetics Home Reference: hypochondroplasia

    MedlinePlus

    ... Description Hypochondroplasia is a form of short-limbed dwarfism. This condition affects the conversion of cartilage into ... Resources MedlinePlus (2 links) Encyclopedia: Lordosis Health Topic: Dwarfism Genetic and Rare Diseases Information Center (1 link) ...

  12. Genetic research in space

    NASA Technical Reports Server (NTRS)

    Delone, N. L.; Antipov, V. V.; Ilyin, Ye. A.

    1988-01-01

    The role of the genetic apparatus in the adaptation of the organism to conditions of weightlessness is studied. The investigation includes studies at the gene, chromosome, cell, tissue, and organism levels, as well as studies at the population level.

  13. Genetics Home Reference: anencephaly

    MedlinePlus

    ... Help Me Understand Genetics Home Health Conditions anencephaly anencephaly Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Anencephaly is a condition that prevents the normal development ...

  14. Difficult Decisions: Genetic Screening.

    ERIC Educational Resources Information Center

    Slesnick, Irwin L.; Parakh, Jal S.

    1988-01-01

    Discusses the issue of mandatory genetic screening. Poses the question of the benefits, drawbacks, and motives involved. Provides a discussion activity to be used in high school biology classes consisting of a hypothetical situation and several questions. (CW)

  15. Genetic Testing and PXE

    MedlinePlus

    ... with PXE International's board certified genetic counselor, please call 202.362.9599. Leave your name, address, email and phone ... Connecticut Avenue NW - Suite 404 • Washington DC 20008-2304 • Telephone: 202.362.9599

  16. Genetics Home Reference: sialidosis

    MedlinePlus

    ... syndrome Related Information How are genetic conditions and genes named? ... Morrone A. Type II sialidosis: review of the clinical spectrum and identification of a new splicing defect with chitotriosidase assessment in two patients. J ...

  17. Genetics of Diabetes

    MedlinePlus

    ... A A A Listen En Español Genetics of Diabetes You've probably wondered how you developed diabetes. ... to develop diabetes than others. What Leads to Diabetes? Type 1 and type 2 diabetes have different ...

  18. Evolving genetic code

    PubMed Central

    OHAMA, Takeshi; INAGAKI, Yuji; BESSHO, Yoshitaka; OSAWA, Syozo

    2008-01-01

    In 1985, we reported that a bacterium, Mycoplasma capricolum, used a deviant genetic code, namely UGA, a “universal” stop codon, was read as tryptophan. This finding, together with the deviant nuclear genetic codes in not a few organisms and a number of mitochondria, shows that the genetic code is not universal, and is in a state of evolution. To account for the changes in codon meanings, we proposed the codon capture theory stating that all the code changes are non-disruptive without accompanied changes of amino acid sequences of proteins. Supporting evidence for the theory is presented in this review. A possible evolutionary process from the ancient to the present-day genetic code is also discussed. PMID:18941287

  19. LSD and Genetic Damage

    ERIC Educational Resources Information Center

    Dishotsky, Norman I.; And Others

    1971-01-01

    Reviews studies of the effects of lysergic acid diethylamide (LSD) on man and other organisms. Concludes that pure LSD injected in moderate doses does not cause chromosome or detectable genetic damage and is not a teratogen or carcinogen. (JM)

  20. Genetics for the ophthalmologist.

    PubMed

    Sadagopan, Karthikeyan A; Capasso, Jenina; Levin, Alex V

    2012-09-01

    The eye has played a major role in human genomics including gene therapy. It is the fourth most common organ system after integument (skin, hair and nails), nervous system, and musculoskeletal system to be involved in genetic disorders. The eye is involved in single gene disorders and those caused by multifactorial etiology. Retinoblastoma was the first human cancer gene to be cloned. Leber hereditary optic neuropathy was the first mitochondrial disorder described. X-Linked red-green color deficiency was the first X-linked disorder described. The eye, unlike any other body organ, allows directly visualization of genetic phenomena such as skewed X-inactivation in the fundus of a female carrier of ocular albinism. Basic concepts of genetics and their application to clinical ophthalmological practice are important not only in making a precise diagnosis and appropriate referral, but also in management and genetic counseling. PMID:23439654

  1. Genetics of adrenal tumors.

    PubMed

    Opocher, G; Schiavi, F; Cicala, M V; Patalano, A; Mariniello, B; Boaretto, F; Zovato, S; Pignataro, V; Macino, B; Negro, I; Mantero, F

    2009-06-01

    The impact of genetics and genomics on clinical medicine is becoming more and more important. Endocrinology pioneered the development of molecular medicine, but also the study of adrenal tumors had a great impact in this field. Particularly important was the detection of genetics of tumors derived from the adrenal medulla, as well as that of those derived from the sympathetic and parasympathetic paraganglia. The identification of mutations in one of the several pheochromocytoma/paraganglioma susceptibility genes may indicate a specific clinical management drive. Less well understood is the genetics of adrenal cortex tumors, in particular adrenocortical carcinoma, a rare and particularly aggressive disease. There are only a few examples of hereditary transmission of adrenocortical carcinoma, but the analysis of low penetrance genes by genome wide association study may enable us to discover new genetic mechanisms responsible for adrenocortical-derived tumors. PMID:19471236

  2. Transgenerational genetic effects

    PubMed Central

    Nelson, Vicki R; Nadeau, Joseph H

    2012-01-01

    Since Mendel, studies of phenotypic variation and disease risk have emphasized associations between genotype and phenotype among affected individuals in families and populations. Although this paradigm has led to important insights into the molecular basis for many traits and diseases, most of the genetic variants that control the inheritance of these conditions continue to elude detection. Recent studies suggest an alternative mode of inheritance where genetic variants that are present in one generation affect phenotypes in subsequent generations, thereby decoupling the conventional relations between genotype and phenotype, and perhaps, contributing to ‘missing heritability’. Under some conditions, these transgenerational genetic effects can be as frequent and strong as conventional inheritance, and can persist for multiple generations. Growing evidence suggests that RNA mediates these heritable epigenetic changes. The primary challenge now is to identify the molecular basis for these effects, characterize mechanisms and determine whether transgenerational genetic effects occur in humans. PMID:22122083

  3. Genetics Home Reference: hypochondrogenesis

    MedlinePlus

    ... and Rare Diseases Information Center Frequency Hypochondrogenesis and achondrogenesis , type 2 (a similar skeletal disorder) together affect ... of hypochondrogenesis: Genetic Testing Registry: ... Achondrogenesis These resources from MedlinePlus offer information about the ...

  4. [Genetic engineering in plants].

    PubMed

    Demarly, Y

    1992-11-01

    Until recent years, plant genetic was involved in heredity studies through the analysis of segregations in progenies after crossing. New potentiality arose as genetic tools with the use of dissociated plant elements, transforming and cultivating them in vitro. When plants are regenerated from manipulated tissues, new structures of varieties (clones) new genotypes (transgenic plants) and new regulations of genes expression (vitrovariants) open new ways for plant genetic engineering. Progressively these technological tools are integrated in the methods of plant breeding. Yet all possible consequences of these new types of heredity and of these new genetic structures must be evaluated. As first priority the analysis of possible incidences in the field of food, nutrition and health gives the basis for diagnostics and organisations aiming to avoid the release of genotypes which could have unwanted effects.

  5. [Genetic effects of radiation].

    PubMed

    Nakamura, Nori

    2012-03-01

    This paper is a short review of genetic effect of radiation. This includes methods and results of a large-scale genetic study on specific loci in mice and of various studies in the offspring of atomic-bomb survivors. As for the latter, there is no results obtained which suggest the effect of parental exposure to radiation. Further, in recent years, studies are conducted to the offspring born to parents who were survivors of childhood cancers. In several reports, the mean gonad dose is quite large whereas in most instances, the results do not indicate genetic effect following parental exposure to radiation. Possible reasons for the difficulties in detecting genetic effect of radiation are discussed. PMID:22514926

  6. Osteonecrosis in genetic disorders

    PubMed Central

    Masi, Laura; Falchetti, Alberto; Brandi, Maria Luisa

    2007-01-01

    The avascular necrosis of bone is characterized by an abnormality of tissue that can occur whenever a disease process causes major cell stress. Some evidence supports a role for genetic factors in some avascular necrosis suggesting that gene mutations could play a role in the pathogenesis of osteonecrosis. These genetic studies provide hope that tools for identifying high risk patients will be available in the future. PMID:22460749

  7. Genetics of epilepsy

    PubMed Central

    Vadlamudi, Lata; Milne, Roger L.; Lawrence, Kate; Heron, Sarah E.; Eckhaus, Jazmin; Keay, Deborah; Connellan, Mary; Torn-Broers, Yvonne; Howell, R. Anne; Mulley, John C.; Scheffer, Ingrid E.; Dibbens, Leanne M.; Hopper, John L.

    2014-01-01

    Objective: Analysis of twins with epilepsy to explore the genetic architecture of specific epilepsies, to evaluate the applicability of the 2010 International League Against Epilepsy (ILAE) organization of epilepsy syndromes, and to integrate molecular genetics with phenotypic analyses. Methods: A total of 558 twin pairs suspected to have epilepsy were ascertained from twin registries (69%) or referral (31%). Casewise concordance estimates were calculated for epilepsy syndromes. Epilepsies were then grouped according to the 2010 ILAE organizational scheme. Molecular genetic information was utilized where applicable. Results: Of 558 twin pairs, 418 had confirmed seizures. A total of 534 twin individuals were affected. There were higher twin concordance estimates for monozygotic (MZ) than for dizygotic (DZ) twins for idiopathic generalized epilepsies (MZ = 0.77; DZ = 0.35), genetic epilepsy with febrile seizures plus (MZ = 0.85; DZ = 0.25), and focal epilepsies (MZ = 0.40; DZ = 0.03). Utilizing the 2010 ILAE scheme, the twin data clearly demonstrated genetic influences in the syndromes designated as genetic. Of the 384 tested twin individuals, 10.9% had mutations of large effect in known epilepsy genes or carried validated susceptibility alleles. Conclusions: Twin studies confirm clear genetic influences for specific epilepsies. Analysis of the twin sample using the 2010 ILAE scheme strongly supported the validity of grouping the “genetic” syndromes together and shows this organizational scheme to be a more flexible and biologically meaningful system than previous classifications. Successful selected molecular testing applied to this cohort is the prelude to future large-scale next-generation sequencing of epilepsy research cohorts. Insights into genetic architecture provided by twin studies provide essential data for optimizing such approaches. PMID:25107880

  8. Genetic testing in hyperlipidemia.

    PubMed

    Bilen, Ozlem; Pokharel, Yashashwi; Ballantyne, Christie M

    2015-05-01

    Hereditary dyslipidemias are often underdiagnosed and undertreated, yet with significant health implications, most importantly causing preventable premature cardiovascular diseases. The commonly used clinical criteria to diagnose hereditary lipid disorders are specific but are not very sensitive. Genetic testing may be of value in making accurate diagnosis and improving cascade screening of family members, and potentially, in risk assessment and choice of therapy. This review focuses on using genetic testing in the clinical setting for lipid disorders, particularly familial hypercholesterolemia.

  9. Genetic Testing in Hyperlipidemia.

    PubMed

    Bilen, Ozlem; Pokharel, Yashashwi; Ballantyne, Christie M

    2016-03-01

    Hereditary dyslipidemias are often underdiagnosed and undertreated, yet with significant health implications, most importantly causing preventable premature cardiovascular diseases. The commonly used clinical criteria to diagnose hereditary lipid disorders are specific but are not very sensitive. Genetic testing may be of value in making accurate diagnosis and improving cascade screening of family members, and potentially, in risk assessment and choice of therapy. This review focuses on using genetic testing in the clinical setting for lipid disorders, particularly familial hypercholesterolemia.

  10. Genetics of Takotsubo Syndrome.

    PubMed

    Limongelli, Giuseppe; Masarone, Daniele; Maddaloni, Valeria; Rubino, Marta; Fratta, Fiorella; Cirillo, Annapaola; Ludovica, Spinelli Barrile; Pacileo, Roberta; Fusco, Adelaide; Coppola, Guido Ronald; Pisacane, Francesca; Bossone, Eduardo; Calabrò, Paolo; Calabrò, Raffaele; Russo, Maria Giovanna; Pacileo, Giuseppe

    2016-10-01

    Takotsubo syndrome (TTS) is an enigmatic disease with a multifactorial and still unresolved pathogenesis. A genetic predisposition has been suggested based on the few familial TTS cases. Conflicting results have been published regarding the role of functional polymorphisms in relevant candidate genes, such as α1-, β1-, and β2-adrenergic receptors; G protein-coupled receptor kinase 5; and estrogen receptors. Further research is required to help clarify the role of genetic susceptibility in TTS. PMID:27638020

  11. Primer on molecular genetics

    SciTech Connect

    Not Available

    1992-04-01

    This report is taken from the April 1992 draft of the DOE Human Genome 1991--1992 Program Report, which is expected to be published in May 1992. The primer is intended to be an introduction to basic principles of molecular genetics pertaining to the genome project. The material contained herein is not final and may be incomplete. Techniques of genetic mapping and DNA sequencing are described.

  12. Contemporary Genetics for Gender Researchers: Not Your Grandma's Genetics Anymore

    ERIC Educational Resources Information Center

    Salk, Rachel H.; Hyde, Janet S.

    2012-01-01

    Over the past century, much of genetics was deterministic, and feminist researchers framed justified criticisms of genetics research. However, over the past two decades, genetics research has evolved remarkably and has moved far from earlier deterministic approaches. Our article provides a brief primer on modern genetics, emphasizing contemporary…

  13. Genetics & sport: bioethical concerns.

    PubMed

    Miah, Andy

    2012-12-01

    This paper provides an overview of the ethical issues pertaining to the use of genetic insights and techniques in sport. Initially, it considers a range of scientific findings that have stimulated debate about the ethical issues associated with genetics applied to sport. It also outlines some of the early policy responses to these discoveries from world leading sports organizations, along with knowledge about actual use of gene technologies in sport. Subsequently, it considers the challenges with distinguishing between therapeutic use and human enhancement within genetic science, which is a particularly important issue for the world of sport. Next, particular attention is given to the use of genetic information, which raises questions about the legitimacy and reliability of genetic tests, along with the potential public value of having DNA databanks to economize in health care. Finally, the ethics of gene transfer are considered, inviting questions into the values of sport and humanity. It argues that, while gene modification may seem conceptually similar to other forms of doping, the requirements upon athletes are such that new forms of enhancement become increasingly necessary to discover. Insofar as genetic science is able to create safer, more effective techniques of human modification, then it may be an appealing route through which to modify athletes to safeguard the future of elite sports as enterprises of human excellence. PMID:22830450

  14. [Molecular and genetic epidemiology].

    PubMed

    Kang, D H

    2001-04-21

    Molecular epidemiology is defined as "the use of biological markers in epidemiologic research" and genetic epidemiology is defined as "the study of the interaction between genetic and environmental factors in epidemiologic research". Traditional epidemiologic approaches defined as "the study of the distribution and determinants of disease frequency in human population" could not address the importance of genetic susceptibility of humans in disease occurrence. However, the use of biological or genetic markers identified and characterized by the help of advance in molecular biology and human genetics now can provide us better understanding of multi-factorial or multistep disease occurrence in humans. Biological markers used in molecular epidemiology are classified into three groups: biomarkers of exposure (i.e., carcinogen metabolites in human urine, DNA-adducts, etc.), biomarkers of effects (i.e., oncoproteins, tumor markers, etc.), and biomarkers of susceptibility (i.e., genetic polymorphisms of carcinogen metabolism enzymes, DNA repair, etc.). Susceptibility genes involved in disease pathogenesis are categorized into two groups: high penetrance genes (i.e., BRAC1, RB, etc.) and low penetrance genes (i.e., GSTs, XRCC1, etc.). This paper will address the usefulnesses of bomarkers in edpidemiologic research and will show the examples of the use of selected low penetrance genes involved in human carcinogenesis. The importance of multidisciplinary approaches among epidemiologists, molecular biologists, and human geneticists will also be discussed.

  15. Genetics & sport: bioethical concerns.

    PubMed

    Miah, Andy

    2012-12-01

    This paper provides an overview of the ethical issues pertaining to the use of genetic insights and techniques in sport. Initially, it considers a range of scientific findings that have stimulated debate about the ethical issues associated with genetics applied to sport. It also outlines some of the early policy responses to these discoveries from world leading sports organizations, along with knowledge about actual use of gene technologies in sport. Subsequently, it considers the challenges with distinguishing between therapeutic use and human enhancement within genetic science, which is a particularly important issue for the world of sport. Next, particular attention is given to the use of genetic information, which raises questions about the legitimacy and reliability of genetic tests, along with the potential public value of having DNA databanks to economize in health care. Finally, the ethics of gene transfer are considered, inviting questions into the values of sport and humanity. It argues that, while gene modification may seem conceptually similar to other forms of doping, the requirements upon athletes are such that new forms of enhancement become increasingly necessary to discover. Insofar as genetic science is able to create safer, more effective techniques of human modification, then it may be an appealing route through which to modify athletes to safeguard the future of elite sports as enterprises of human excellence.

  16. Ecogeographic Genetic Epidemiology

    PubMed Central

    Sloan, Chantel D.; Duell, Eric J.; Shi, Xun; Irwin, Rebecca; Andrew, Angeline S.; Williams, Scott M.; Moore, Jason H.

    2009-01-01

    Complex diseases such as cancer and heart disease result from interactions between an individual's genetics and environment, i.e. their human ecology. Rates of complex diseases have consistently demonstrated geographic patterns of incidence, or spatial “clusters” of increased incidence relative to the general population. Likewise, genetic subpopulations and environmental influences are not evenly distributed across space. Merging appropriate methods from genetic epidemiology, ecology and geography will provide a more complete understanding of the spatial interactions between genetics and environment that result in spatial patterning of disease rates. Geographic Information Systems (GIS), which are tools designed specifically for dealing with geographic data and performing spatial analyses to determine their relationship, are key to this kind of data integration. Here the authors introduce a new interdisciplinary paradigm, ecogeographic genetic epidemiology, which uses GIS and spatial statistical analyses to layer genetic subpopulation and environmental data with disease rates and thereby discern the complex gene-environment interactions which result in spatial patterns of incidence. PMID:19025788

  17. Genetic Manipulation in Pigs

    PubMed Central

    Sachs, David H.; Galli, Cesare

    2009-01-01

    Purpose of Review Recent developments in the field of genetic engineering have made it possible to add, delete or exchange genes from one species to another. This technology has special relevance to the field of xenotransplantation, in which the elimination of a species-specific disparity could make the difference between success or failure of an organ transplant. This review focuses on developments in both the techniques and applications of genetically modified animals. Recent Findings Advances have been made using existing techniques for genetic modifications of swine and in the development of new, emerging technologies, including enzymatic engineering and the use of siRNA. Applications of the modified animals have provided evidence that genetically modified swine have the potential to overcome both physiologic and immunologic barriers that have previously impeded this field. Use of GalT-KO animals as donors have shown marked improvements in xenograft survivals. Summary Techniques for genetic engineering of swine have been directed toward avoiding naturally existing cellular and antibody responses to species-specific antigens. Organs from genetically engineered animals have enjoyed markedly improved survivals in non-human primates, especially in protocols directed toward the induction of tolerance, presumably by avoiding immunization to new antigens. PMID:19469029

  18. Genetic aspects of arteriosclerosis.

    PubMed

    Goldbourt, U; Neufeld, H N

    1986-01-01

    This review discusses the genetic factors in the development of arteriosclerosis and coronary heart disease (CHD). In several studies, multivariate analysis of prospective mortality/morbidity data and angiographic findings have indicated that a family history of CHD contributed to CHD risk independently of the established risk factors. In addition, ethnic groups that differ in the prevalence and incidence of CHD also markedly differ in blood groups and protein-enzymatic markers. These or other genetic differences may affect CHD rates. Data from fraternal and identical twins, the source of some early genetic CHD findings, are reviewed. Genetic disorders of lipoprotein metabolism and transport, such as familial hypercholesterolemia, as well as other monogenic disorders are discussed. The role of apoprotein E polymorphism i other monogenic disorders are discussed. The role of apoprotein E polymorphism in determining plasma LDL variability among individuals is considered. Recombinant DNA technology, molecular cloning, and the identification of restriction fragment length polymorphisms are new tools for investigators who assess DNA polymorphism. Recent advances in that domain include: DNA polymorphisms affecting blood levels of apo A-I and A-II, association of a DNA insertion on chromosome 19 with severe premature atherosclerosis, and information concerning linkage of the genes for various apolipoproteins. In addition, the evidence for a major genetic component in diabetes mellitus and research into the genetic aspects of hypertension are reviewed. The male/female ratio in pathologically and epidemiologically assessed atherosclerosis may provide clues to the role of genetics. Early structural changes in the coronary artery intima are compatible with the ethnic and gender predilection. A key question in understanding underlying mechanisms in atherosclerosis is why coronary arteries are occluded in individuals whose other arterial systems are largely unaffected. The

  19. High Points of Human Genetics

    ERIC Educational Resources Information Center

    Stern, Curt

    1975-01-01

    Discusses such high points of human genetics as the study of chromosomes, somatic cell hybrids, the population formula: the Hardy-Weinberg Law, biochemical genetics, the single-active X Theory, behavioral genetics and finally how genetics can serve humanity. (BR)

  20. [Genetic aspects of genealogy].

    PubMed

    Tetushkin, E Iu

    2011-11-01

    The supplementary historical discipline genealogy is also a supplementary genetic discipline. In its formation, genetics borrowed from genealogy some methods of pedigree analysis. In the 21th century, it started receiving contribution from computer-aided genealogy and genetic (molecular) genealogy. The former provides novel tools for genetics, while the latter, which employing genetic methods, enriches genetics with new evidence. Genealogists formulated three main laws ofgenealogy: the law of three generations, the law of doubling the ancestry number, and the law of declining ancestry. The significance and meaning of these laws can be fully understood only in light of genetics. For instance, a controversy between the exponential growth of the number of ancestors of an individual, i.e., the law of doubling the ancestry number, and the limited number of the humankind is explained by the presence of weak inbreeding because of sibs' interference; the latter causes the pedigrees' collapse, i.e., explains also the law of diminishing ancestry number. Mathematic modeling of pedigrees' collapse presented in a number of studies showed that the number of ancestors of each individual attains maximum in a particular generation termed ancestry saturated generation. All representatives of this and preceding generation that left progeny are common ancestors of all current members of the population. In subdivided populations, these generations are more ancient than in panmictic ones, whereas in small isolates and social strata with limited numbers of partners, they are younger. The genealogical law of three generations, according to which each hundred years contain on average three generation intervals, holds for generation lengths for Y-chromosomal DNA, typically equal to 31-32 years; for autosomal and mtDNA, this time is somewhat shorter. Moving along ascending lineas, the number of genetically effective ancestors transmitting their DNA fragment to descendants increases far

  1. From observational to dynamic genetics

    PubMed Central

    Haworth, Claire M. A.; Davis, Oliver S. P.

    2014-01-01

    Twin and family studies have shown that most traits are at least moderately heritable. But what are the implications of finding genetic influence for the design of intervention and prevention programs? For complex traits, heritability does not mean immutability, and research has shown that genetic influences can change with age, context, and in response to behavioral and drug interventions. The most significant implications for intervention will come when we move from observational genetics to investigating dynamic genetics, including genetically sensitive interventions. Future interventions should be designed to overcome genetic risk and draw upon genetic strengths by changing the environment. PMID:24478793

  2. Genetic epidemiology, genetic maps and positional cloning.

    PubMed Central

    Morton, Newton E

    2003-01-01

    Genetic epidemiology developed in the middle of the last century, focused on inherited causes of disease but with methods and results applicable to other traits and even forensics. Early success with linkage led to the localization of genes contributing to disease, and ultimately to the Human Genome Project. The discovery of millions of DNA markers has encouraged more efficient positional cloning by linkage disequilibrium (LD), using LD maps and haplotypes in ways that are rapidly evolving. This has led to large international programmes, some promising and others alarming, with laws about DNA patenting and ethical guidelines for responsible research still struggling to be born. PMID:14561327

  3. Frequently Asked Questions about Genetic Testing

    MedlinePlus

    ... sobre las pruebas genéticas Frequently Asked Questions About Genetic Testing What is genetic testing? What can I ... find more information about genetic testing? What is genetic testing? Genetic testing uses laboratory methods to look ...

  4. [Genetics of pediatric obesity].

    PubMed

    Peralta-Romero, José de Jesús; Gómez-Zamudio, Jaime Héctor; Estrada-Velasco, Bárbara; Karam-Araujo, Roberto; Cruz-López, Miguel

    2014-01-01

    Obesity is a major health problem around the globe. The statistics of overweight and obesity at early ages have reached alarming levels and placed our country in the first place in regard to childhood obesity. In the development of obesity two major factors take part, one genetic and the other one environmental. From the perspective of environmental changes both overweight and obesity result from the imbalance in the energy balance: people ingest more energy than they expend. Despite people live in the same obesogenic environment not all of them develop obesity; it requires genetic factors for this to happen. This review focuses on the description of the main methodologies to find genetic markers, as well as the main loci in candidate genes, whose single nucleotide polymorphisms (SNPs) are associated with obesity and its comorbidities in children, highlighting the association of these genes in the Mexican population. Knowledge of the genetic markers associated with obesity will help to understand the molecular and physiological mechanisms, the genetic background and changes in body mass index in the Mexican population. This information is useful for the planning of new hypotheses in the search for new biomarkers that can be used in a predictive and preventive way, as well as for the development of new therapeutic strategies.

  5. Genetics of Vesicoureteral Reflux

    PubMed Central

    Ninoa, F.; Ilaria, M.; Noviello, C.; Santoro, L.; Rätsch, I.M.; Martino, A.; Cobellis, G.

    2016-01-01

    Vesicoureteral reflux (VUR) is the retrograde passage of urine from the bladder to the upper urinary tract. It is the most common congenital urological anomaly affecting 1-2% of children and 30-40% of patients with urinary tract infections. VUR is a major risk factor for pyelonephritic scarring and chronic renal failure in children. It is the result of a shortened intravesical ureter with an enlarged or malpositioned ureteric orifice. An ectopic embryonal ureteric budding development is implicated in the pathogenesis of VUR, which is a complex genetic developmental disorder. Many genes are involved in the ureteric budding formation and subsequently in the urinary tract and kidney development. Previous studies demonstrate an heterogeneous genetic pattern of VUR. In fact no single major locus or gene for primary VUR has been identified. It is likely that different forms of VUR with different genetic determinantes are present. Moreover genetic studies of syndromes with associated VUR have revealed several possible candidate genes involved in the pathogenesis of VUR and related urinary tract malformations. Mutations in genes essential for urinary tract morphogenesis are linked to numerous congenital syndromes, and in most of those VUR is a feature. The Authors provide an overview of the developmental processes leading to the VUR. The different genes and signaling pathways controlling the embryonal urinary tract development are analyzed. A better understanding of VUR genetic bases could improve the management of this condition in children. PMID:27013925

  6. Behavioural genetics and temperament.

    PubMed

    Plomin, R

    1982-01-01

    Three recent developments in behavioural genetics are relevant to temperament research. First, the search for genetic influences on temperament has been frustrated by the finding that twin studies using self-report and parental rating instruments detect a genetic influence for all personality traits whereas twin studies using objective assessments rarely find a genetic influence. Secondly, environmental influences salient to temperament appear to operate in such a way as to make members of a family (siblings, for example) as different from one another as are individuals in different families. The importance of such 'E1', or non-shared, environmental influences suggests the need for studies of more than one child per family. Thirdly, adoption studies are needed to complement the extensive research on temperament in twins. In addition to its usefulness in isolating genetic influences, the adoption design can study environmental influence devoid of the confounding effects of hereditary influences; it can also isolate interactions between genotypes and environments. Preliminary results from the Colorado Adoption Project show little relationship between the temperaments of adopted and non-adopted one-year-olds and the personality characteristics of thier parents. Measures of the home and family environment did not relate to infant temperament, and no genotype-environment interaction was detected.

  7. Genetical background of intelligence.

    PubMed

    Junkiert-Czarnecka, Anna; Haus, Olga

    2016-01-01

    Intelligence as an ability to reason, think abstractly and adapt effectively to the environment is a subject of research in the field of psychology, neurobiology, and in the last twenty years genetics as well. Genetical testing of twins carried out from XX century indicated heritebility of intelligence, therefore confirmed an influence of genetic factor on cognitive processes. Studies on genetic background of intelligence focus on dopaminergic (DRD2, DRD4, COMT, SLC6A3, DAT1, CCKAR) and adrenergic system (ADRB2, CHRM2) genes as well as, neutrofins (BDNF) and oxidative stress genes (LTF, PRNP). Positive effect of investigated gene polymorphism was indicated by variation c.957C>T DRD2 gene (if in polymorphic site is thymine), polymorphism c.472G>A COMT gene (presence of adenine) and also gene ADRB2 c.46A->G (guanine), CHRM2 (thymine in place c.1890A>T) and BDNF (guanine in place c.472G>A) Obtained results indicate that intelligence is a feature dependent not only on genetic but also an environmental factor. PMID:27333929

  8. Genetic modulation of homocysteinemia.

    PubMed

    Rozen, R

    2000-01-01

    With the identification of hyperhomocysteinemia as a risk factor for cardiovascular disease, an understanding of the genetic determinants of plasma homocysteine is important for prevention and treatment. It has been known for some time that homocystinuria, a rare inborn error of metabolism, can be due to genetic mutations that severely disrupt homocysteine metabolism. A more recent development is the finding that milder, but more common, genetic mutations in the same enzymes might also contribute to an elevation in plasma homocysteine. The best example of this concept is a missense mutation (alanine to valine) at base pair (bp) 677 of methylenetetrahydrofolate reductase (MTHFR), the enzyme that provides the folate derivative for conversion of homocysteine to methionine. This mutation results in mild hyperhomocysteinemia, primarily when folate levels are low, providing a rationale (folate supplementation) for overcoming the genetic deficiency. Additional genetic variants in MTHFR and in other enzymes of homocysteine metabolism are being identified as the cDNAs/genes become isolated. These variants include a glutamate to alanine mutation (bp 1298) in MTHFR, an aspartate to glycine mutation (bp 2756) in methionine synthase, and an isoleucine to methionine mutation (bp 66) in methionine synthase reductase. These variants have been identified relatively recently; therefore additional investigations are required to determine their clinical significance with respect to mild hyperhomocysteinemia and vascular disease.

  9. Constraints in Genetic Programming

    NASA Technical Reports Server (NTRS)

    Janikow, Cezary Z.

    1996-01-01

    Genetic programming refers to a class of genetic algorithms utilizing generic representation in the form of program trees. For a particular application, one needs to provide the set of functions, whose compositions determine the space of program structures being evolved, and the set of terminals, which determine the space of specific instances of those programs. The algorithm searches the space for the best program for a given problem, applying evolutionary mechanisms borrowed from nature. Genetic algorithms have shown great capabilities in approximately solving optimization problems which could not be approximated or solved with other methods. Genetic programming extends their capabilities to deal with a broader variety of problems. However, it also extends the size of the search space, which often becomes too large to be effectively searched even by evolutionary methods. Therefore, our objective is to utilize problem constraints, if such can be identified, to restrict this space. In this publication, we propose a generic constraint specification language, powerful enough for a broad class of problem constraints. This language has two elements -- one reduces only the number of program instances, the other reduces both the space of program structures as well as their instances. With this language, we define the minimal set of complete constraints, and a set of operators guaranteeing offspring validity from valid parents. We also show that these operators are not less efficient than the standard genetic programming operators if one preprocesses the constraints - the necessary mechanisms are identified.

  10. Extensive genetics of ALS

    PubMed Central

    Calvo, Andrea; Mazzini, Letizia; Cantello, Roberto; Mora, Gabriele; Moglia, Cristina; Corrado, Lucia; D'Alfonso, Sandra; Majounie, Elisa; Renton, Alan; Pisano, Fabrizio; Ossola, Irene; Brunetti, Maura; Traynor, Bryan J.; Restagno, Gabriella

    2012-01-01

    Objective: To assess the frequency and clinical characteristics of patients with mutations of major amyotrophic lateral sclerosis (ALS) genes in a prospectively ascertained, population-based epidemiologic series of cases. Methods: The study population includes all ALS cases diagnosed in Piemonte, Italy, from January 2007 to June 2011. Mutations of SOD1, TARDBP, ANG, FUS, OPTN, and C9ORF72 have been assessed. Results: Out of the 475 patients included in the study, 51 (10.7%) carried a mutation of an ALS-related gene (C9ORF72, 32; SOD1, 10; TARDBP, 7; FUS, 1; OPTN, 1; ANG, none). A positive family history for ALS or frontotemporal dementia (FTD) was found in 46 (9.7%) patients. Thirty-one (67.4%) of the 46 familial cases and 20 (4.7%) of the 429 sporadic cases had a genetic mutation. According to logistic regression modeling, besides a positive family history for ALS or FTD, the chance to carry a genetic mutation was related to the presence of comorbid FTD (odds ratio 3.5; p = 0.001), and age at onset ≤54 years (odds ratio 1.79; p = 0.012). Conclusions: We have found that ∼11% of patients with ALS carry a genetic mutation, with C9ORF72 being the commonest genetic alteration. Comorbid FTD or a young age at onset are strong indicators of a possible genetic origin of the disease. PMID:23100398

  11. Genetics of Vesicoureteral Reflux.

    PubMed

    Nino, F; Ilari, M; Noviello, C; Santoro, L; Rätsch, I M; Martino, A; Cobellis, G

    2016-02-01

    Vesicoureteral reflux (VUR) is the retrograde passage of urine from the bladder to the upper urinary tract. It is the most common congenital urological anomaly affecting 1-2% of children and 30-40% of patients with urinary tract infections. VUR is a major risk factor for pyelonephritic scarring and chronic renal failure in children. It is the result of a shortened intravesical ureter with an enlarged or malpositioned ureteric orifice. An ectopic embryonal ureteric budding development is implicated in the pathogenesis of VUR, which is a complex genetic developmental disorder. Many genes are involved in the ureteric budding formation and subsequently in the urinary tract and kidney development. Previous studies demonstrate an heterogeneous genetic pattern of VUR. In fact no single major locus or gene for primary VUR has been identified. It is likely that different forms of VUR with different genetic determinantes are present. Moreover genetic studies of syndromes with associated VUR have revealed several possible candidate genes involved in the pathogenesis of VUR and related urinary tract malformations. Mutations in genes essential for urinary tract morphogenesis are linked to numerous congenital syndromes, and in most of those VUR is a feature. The Authors provide an overview of the developmental processes leading to the VUR. The different genes and signaling pathways controlling the embryonal urinary tract development are analyzed. A better understanding of VUR genetic bases could improve the management of this condition in children. PMID:27013925

  12. Genetics in Osteoarthritis

    PubMed Central

    Fernández-Moreno, Mercedes; Rego, Ignacio; Carreira-Garcia, Vanessa; Blanco, Francisco J

    2008-01-01

    Osteoarthritis is a degenerative articular disease with complex pathogeny because diverse factors interact causing a process of deterioration of the cartilage. Despite the multifactorial nature of this pathology, from the 50’s it´s known that certain forms of osteoarthritis are related to a strong genetic component. The genetic bases of this disease do not follow the typical patterns of mendelian inheritance and probably they are related to alterations in multiple genes. The identification of a high number of candidate genes to confer susceptibility to the development of the osteoarthritis shows the complex nature of this disease. At the moment, the genetic mechanisms of this disease are not known, however, which seems clear is that expression levels of several genes are altered, and that the inheritance will become a substantial factor in future considerations of diagnosis and treatment of the osteoarthritis. PMID:19516961

  13. Population genetics of Lithuanians.

    PubMed

    Ku inskas, V

    2001-01-01

    The primary objective of this article was to overview the present-day knowledge on genetic features of the Lithuanian population. Genetic differentiation within the Lithuanian population and the relationship between Lithuanians and other European populations was analysed by means of blood groups, serum protein polymorphisms and DNA markers including mtDNA. The results of the research have shown small differences between present-day Lithuanian ethnolinguistic groups, which probably go back to the prehistoric Baltic tribal structure. The Baltic peoples show a mixture of eastern and western genetic traits, e.g. a high frequency of the blood group B combined with a very high frequency of the Rh-negative blood group. Studies of the Baltic 'tribal gene' LWb indicate the presence of a considerable Baltic admixture in the neighbouring Finno-Ugric and Slavic populations.

  14. Intelligence, race, and genetics.

    PubMed

    Sternberg, Robert J; Grigorenko, Elena L; Kidd, Kenneth K

    2005-01-01

    In this article, the authors argue that the overwhelming portion of the literature on intelligence, race, and genetics is based on folk taxonomies rather than scientific analysis. They suggest that because theorists of intelligence disagree as to what it is, any consideration of its relationships to other constructs must be tentative at best. They further argue that race is a social construction with no scientific definition. Thus, studies of the relationship between race and other constructs may serve social ends but cannot serve scientific ends. No gene has yet been conclusively linked to intelligence, so attempts to provide a compelling genetic link of race to intelligence are not feasible at this time. The authors also show that heritability, a behavior-genetic concept, is inadequate in regard to providing such a link.

  15. Imposing genetic diversity.

    PubMed

    Sparrow, Robert

    2015-01-01

    The idea that a world in which everyone was born "perfect" would be a world in which something valuable was missing often comes up in debates about the ethics of technologies of prenatal testing and preimplantation genetic diagnosis (PGD). This thought plays an important role in the "disability critique" of prenatal testing. However, the idea that human genetic variation is an important good with significant benefits for society at large is also embraced by a wide range of figures writing in the bioethics literature, including some who are notoriously hostile to the idea that we should not select against disability. By developing a number of thought experiments wherein we are to contemplate increasing genetic diversity from a lower baseline in order to secure this value, I argue that this powerful intuition is more problematic than is generally recognized, especially where the price of diversity is the well-being of particular individuals. PMID:26030484

  16. Enhancing genetic virtue.

    PubMed

    Walker, Mark

    2009-09-01

    The Genetic Virtue Project (GVP) is a proposed interdisciplinary effort between philosophers, psychologists and geneticists to discover and enhance human ethics using biotechnology genetic correlates of virtuous behavior. The empirical plausibility that virtues have biological correlates is based on the claims that (a) virtues are a subset of personality, specifically, personality traits conceived of as "enduring behaviors," and (b) that there is ample evidence that personality traits have a genetic basis. The moral necessity to use the GVP for moral enhancement is based on the claims that we should eliminate evil (as understood generically, not religiously), as some evil is a function of human nature. The GVP is defended against several ethical and political criticisms.

  17. Genetics of opiate addiction.

    PubMed

    Reed, Brian; Butelman, Eduardo R; Yuferov, Vadim; Randesi, Matthew; Kreek, Mary Jeanne

    2014-11-01

    Addiction to MOP-r agonists such as heroin (and also addiction to prescription opioids) has reemerged as an epidemic in the twenty first century, causing massive morbidity. Understanding the genetics contributing to susceptibility to this disease is crucial for the identification of novel therapeutic targets, and also for discovery of genetic markers which would indicate relative protection or vulnerability from addiction, and relative responsiveness to pharmacotherapy. This information could thus eventually inform clinical practice. In this review, we focus primarily on association studies of heroin and opiate addiction, and further describe the studies which have been replicated in this field, and are thus more likely to be useful for translational efforts.

  18. [Genetics of schizophrenia].

    PubMed

    Jitoku, Daisuke; Yoshikawa, Takeo

    2013-04-01

    Many studies have reported that genetic variants play a major role in the pathogenesis of schizophrenia. In the past five years, the genetics knowledge base of schizophrenia has advanced considerably. These advances have mostly been through genome-wide association studies (GWAS) and copy number variations (CNVs) studies. Moreover, exome sequencing by using the next-generation DNA sequencers is launched in recent years. In the next few years, the high-throughput sequencing is likely to play an important role. These findings have produced new hypotheses about etiology of schizophrenia and they can indicate future research strategies. Therefore, it is expected that further studies will yield deeper insights. PMID:23678585

  19. The genetics of the epilepsies.

    PubMed

    El Achkar, Christelle M; Olson, Heather E; Poduri, Annapurna; Pearl, Phillip L

    2015-07-01

    While genetic causes of epilepsy have been hypothesized from the time of Hippocrates, the advent of new genetic technologies has played a tremendous role in elucidating a growing number of specific genetic causes for the epilepsies. This progress has contributed vastly to our recognition of the epilepsies as a diverse group of disorders, the genetic mechanisms of which are heterogeneous. Genotype-phenotype correlation, however, is not always clear. Nonetheless, the developments in genetic diagnosis raise the promise of a future of personalized medicine. Multiple genetic tests are now available, but there is no one test for all possible genetic mutations, and the balance between cost and benefit must be weighed. A genetic diagnosis, however, can provide valuable information regarding comorbidities, prognosis, and even treatment, as well as allow for genetic counseling. In this review, we will discuss the genetic mechanisms of the epilepsies as well as the specifics of particular genetic epilepsy syndromes. We will include an overview of the available genetic testing methods, the application of clinical knowledge into the selection of genetic testing, genotype-phenotype correlations of epileptic disorders, and therapeutic advances as well as a discussion of the importance of genetic counseling. PMID:26008807

  20. Genetic algorithms based on genetic grammar

    NASA Astrophysics Data System (ADS)

    Hofestaedt, Ralf; Mueller, Hermann

    1992-08-01

    The cell represents the basic unit of life. It can be interpreted as a chemical machine which can solve special problems. The present knowledge we have of molecular biology allows the characterization of the metabolism as a processing method. This method is an evolutionary product which has been developed over millions of years. First we will present the analyzed features of the metabolism. Then we will go on to compare this processing method with methods which are discussed in computer science. The comparison shows that there is no method in the field of computer science which uses all the metabolic features. This is the reason why we formalize the metabolic processing method. In this paper we choose to use a grammatical formalism. A genetic grammar is the basis of the metabolic system which represents the metabolic processing method. The basic unit of this system (logic unit) will be shown. This allows the discussion of the complexity of realizing the metabolic system in hardware.

  1. Pediatric genetic disorders of lens.

    PubMed

    Nihalani, Bharti R

    2014-12-01

    Pediatric genetic disorders of lens include various cataractous and non-cataractous anomalies. The purpose of this review is to help determine the genetic cause based on the lens appearance, ocular and systemic associations. Children with bilateral cataracts require a comprehensive history, ophthalmic and systemic examination to guide further genetic evaluation. With advancements in genetics, it is possible to determine the genetic mutations and assess phenotype genotype correlation in different lens disorders. The genetic diagnosis helps the families to better understand the disorder and develop realistic expectations as to the course of their child's disorder. PMID:27625879

  2. Pediatric genetic disorders of lens

    PubMed Central

    Nihalani, Bharti R.

    2014-01-01

    Pediatric genetic disorders of lens include various cataractous and non-cataractous anomalies. The purpose of this review is to help determine the genetic cause based on the lens appearance, ocular and systemic associations. Children with bilateral cataracts require a comprehensive history, ophthalmic and systemic examination to guide further genetic evaluation. With advancements in genetics, it is possible to determine the genetic mutations and assess phenotype genotype correlation in different lens disorders. The genetic diagnosis helps the families to better understand the disorder and develop realistic expectations as to the course of their child's disorder.

  3. Paper Genetic Engineering.

    ERIC Educational Resources Information Center

    MacClintic, Scott D.; Nelson, Genevieve M.

    Bacterial transformation is a commonly used technique in genetic engineering that involves transferring a gene of interest into a bacterial host so that the bacteria can be used to produce large quantities of the gene product. Although several kits are available for performing bacterial transformation in the classroom, students do not always…

  4. Genetic Building Blocks

    ERIC Educational Resources Information Center

    Roberg, Ezra

    2004-01-01

    The "Central Dogma" of genetics states that one gene, located in a DNA molecule, is ultimately translated into one protein. As important as this idea is, many teachers shy away from teaching the actual mechanism of gene translation, and many students find the concepts abstract and inaccessible. This article describes a unit, called Genetics…

  5. Solving Problems in Genetics

    ERIC Educational Resources Information Center

    Aznar, Mercedes Martinez; Orcajo, Teresa Ibanez

    2005-01-01

    A teaching unit on genetics and human inheritance using problem-solving methodology was undertaken with fourth-level Spanish Secondary Education students (15 year olds). The goal was to study certain aspects of the students' learning process (concepts, procedures and attitude) when using this methodology in the school environment. The change…

  6. Molecular genetics of ependymoma

    PubMed Central

    Yao, Yuan; Mack, Stephen C.; Taylor, Michael D.

    2011-01-01

    Brain tumors are the leading cause of cancer death in children, with ependymoma being the third most common and posing a significant clinical burden. Its mechanism of pathogenesis, reliable prognostic indicators, and effective treatments other than surgical resection have all remained elusive. Until recently, ependymoma research was hindered by the small number of tumors available for study, low resolution of cytogenetic techniques, and lack of cell lines and animal models. Ependymoma heterogeneity, which manifests as variations in tumor location, patient age, histological grade, and clinical behavior, together with the observation of a balanced genomic profile in up to 50% of cases, presents additional challenges in understanding the development and progression of this disease. Despite these difficulties, we have made significant headway in the past decade in identifying the genetic alterations and pathways involved in ependymoma tumorigenesis through collaborative efforts and the application of microarray-based genetic (copy number) and transcriptome profiling platforms. Genetic characterization of ependymoma unraveled distinct mRNA-defined subclasses and led to the identification of radial glial cells as its cell type of origin. This review summarizes our current knowledge in the molecular genetics of ependymoma and proposes future research directions necessary to further advance this field. PMID:21959044

  7. Genetically Engineering Entomopathogenic Fungi.

    PubMed

    Zhao, H; Lovett, B; Fang, W

    2016-01-01

    Entomopathogenic fungi have been developed as environmentally friendly alternatives to chemical insecticides in biocontrol programs for agricultural pests and vectors of disease. However, mycoinsecticides currently have a small market share due to low virulence and inconsistencies in their performance. Genetic engineering has made it possible to significantly improve the virulence of fungi and their tolerance to adverse conditions. Virulence enhancement has been achieved by engineering fungi to express insect proteins and insecticidal proteins/peptides from insect predators and other insect pathogens, or by overexpressing the pathogen's own genes. Importantly, protein engineering can be used to mix and match functional domains from diverse genes sourced from entomopathogenic fungi and other organisms, producing insecticidal proteins with novel characteristics. Fungal tolerance to abiotic stresses, especially UV radiation, has been greatly improved by introducing into entomopathogens a photoreactivation system from an archaean and pigment synthesis pathways from nonentomopathogenic fungi. Conversely, gene knockout strategies have produced strains with reduced ecological fitness as recipients for genetic engineering to improve virulence; the resulting strains are hypervirulent, but will not persist in the environment. Coupled with their natural insect specificity, safety concerns can also be mitigated by using safe effector proteins with selection marker genes removed after transformation. With the increasing public concern over the continued use of synthetic chemical insecticides and growing public acceptance of genetically modified organisms, new types of biological insecticides produced by genetic engineering offer a range of environmentally friendly options for cost-effective control of insect pests. PMID:27131325

  8. Genetics of atopic dermatitis.

    PubMed

    Bussmann, Caroline; Weidinger, Stephan; Novak, Natalija

    2011-09-01

    Atopic dermatitis (AD) is a multifactorial disease, with a strong genetic predisposition. Genome-wide studies as well as candidate gene studies revealed several susceptibility loci. Since the observation of a strong association of "loss of function" mutations in the filaggrin gene with AD, the epidermal barrier was rediscovered as important pathophysiological co-factor of this disease. PMID:21518425

  9. [Genetics of contact allergy].

    PubMed

    Schnuch, A

    2011-10-01

    The genetics of contact allergy (CA) is still only partly understood, despite decades of research. This might be due to inadequately defined phenotypes used in the past. Therefore we suggested studying an extreme phenotype, namely, polysensitization (sensitization to 3 or more unrelated allergens). Another approach to unravel the genetics of CA has been the study of candidate genes. In this review, we summarize studies on the associations between genetic variation (e.g. SNPs) in certain candidate genes and CA. The following polymorphisms and mutations were studied: (1) filaggrin, (2) N-acetyltransferase (NAT1 and 2), (3) glutathione-S-transferase (GST M and T), (4) manganese superoxide dismutase, (5) angiotensin-converting enzyme (ACE), (6) tumor necrosis factor (TNF), and (7) interleukin-16 (IL16). The polymorphisms of NAT1/2, GST M/T, ACE, TNF, and IL16 were shown to be associated with an increased risk of CA. In one of our studies, the increased risk conferred by the TNF and IL16 polymorphisms was confined to polysensitized individuals. Other relevant candidate genes may be identified by studying diseases related to CA in terms of clinical symptoms, a more general pathology (inflammation) and possibly an overlapping genetic background, such as irritant contact dermatitis. PMID:21904893

  10. The revised genetic code

    NASA Astrophysics Data System (ADS)

    Ninio, Jacques

    1990-03-01

    Recent findings on the genetic code are reviewed, including selenocysteine usage, deviations in the assignments of sense and nonsense codons, RNA editing, natural ribosomal frameshifts and non-orthodox codon-anticodon pairings. A multi-stage codon reading process is presented.

  11. Genetics and Genomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Good progress is being made on genetics and genomics of sugar beet, however it is in process and the tools are now being generated and some results are being analyzed. The GABI BeetSeq project released a first draft of the sugar beet genome of KWS2320, a dihaploid (see http://bvseq.molgen.mpg.de/Gen...

  12. Safe genetically engineered plants

    NASA Astrophysics Data System (ADS)

    Rosellini, D.; Veronesi, F.

    2007-10-01

    The application of genetic engineering to plants has provided genetically modified plants (GMPs, or transgenic plants) that are cultivated worldwide on increasing areas. The most widespread GMPs are herbicide-resistant soybean and canola and insect-resistant corn and cotton. New GMPs that produce vaccines, pharmaceutical or industrial proteins, and fortified food are approaching the market. The techniques employed to introduce foreign genes into plants allow a quite good degree of predictability of the results, and their genome is minimally modified. However, some aspects of GMPs have raised concern: (a) control of the insertion site of the introduced DNA sequences into the plant genome and of its mutagenic effect; (b) presence of selectable marker genes conferring resistance to an antibiotic or an herbicide, linked to the useful gene; (c) insertion of undesired bacterial plasmid sequences; and (d) gene flow from transgenic plants to non-transgenic crops or wild plants. In response to public concerns, genetic engineering techniques are continuously being improved. Techniques to direct foreign gene integration into chosen genomic sites, to avoid the use of selectable genes or to remove them from the cultivated plants, to reduce the transfer of undesired bacterial sequences, and make use of alternative, safer selectable genes, are all fields of active research. In our laboratory, some of these new techniques are applied to alfalfa, an important forage plant. These emerging methods for plant genetic engineering are briefly reviewed in this work.

  13. Genetic disorders of collagen.

    PubMed Central

    Tsipouras, P; Ramirez, F

    1987-01-01

    Osteogenesis imperfecta, Ehlers-Danlos syndrome, and Marfan syndrome form a group of genetic disorders of connective tissue. These disorders exhibit remarkable clinical heterogeneity which reflects their underlying biochemical and molecular differences. Defects in collagen types I and III have been found in all three syndromes. PMID:3543367

  14. Behavioural genetics: An introduction.

    PubMed

    Sluyter, F; Ellenbroek, B A

    1999-06-01

    Behavioural genetics is the study of the hereditary influence on behaviour, and can therefore be regarded as the intersection between behavioural sciences and genetics. As with most other fields of research it is difficult to exactly pinpoint when behavioural genetics started. In fact, one might say that the notion behavioural traits can be inherited may have appeared in human thought as early at 8000 BC, when the domestication of the dog began. The scientific era of behavioural genetics is generally considered to start with Charles Darwin. In his famous book On the Origin of Species by Means of natural Selection, or the Preservation of favoured Races in the Struggle for Life, published in 1859 (and sold out the first day), he devoted an entire chapter on instinctive behavioural patterns. Some years later, in his book The Descent of Man and Selection in Relation to Sex, he clearly stated that the difference between the mind of a human being and the mind of an animal 'is certainly one of degree and not of kind'. Moreover he gave considerable thought that mental powers (and insanity) are heritable aspects.

  15. Intelligence, Race, and Genetics

    ERIC Educational Resources Information Center

    Sternberg, Robert J.; Grigorenko, Elena L.; Kidd, Kenneth K.

    2005-01-01

    In this article, the authors argue that the overwhelming portion of the literature on intelligence, race, and genetics is based on folk taxonomies rather than scientific analysis. They suggest that because theorists of intelligence disagree as to what it is, any consideration of its relationships to other constructs must be tentative at best. They…

  16. Genetic Dominance & Cellular Processes

    ERIC Educational Resources Information Center

    Seager, Robert D.

    2014-01-01

    In learning genetics, many students misunderstand and misinterpret what "dominance" means. Understanding is easier if students realize that dominance is not a mechanism, but rather a consequence of underlying cellular processes. For example, metabolic pathways are often little affected by changes in enzyme concentration. This means that…

  17. Maize Genetic Resources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter describes the resources held at the Maize Genetics Cooperation • Stock Center in detail and also provides some information about the North Central Regional Plant Introduction Station (NCRPIS) in Ames, IA, Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) in Mexico, and the N...

  18. Genetics of Retinoblastoma.

    PubMed

    Mallipatna, Ashwin; Marino, Meghan; Singh, Arun D

    2016-01-01

    Retinoblastoma is a malignant retinal tumor that affects young children. Mutations in the RB1 gene cause retinoblastoma. Mutations in both RB1 alleles within the precursor retinal cell are essential, with one mutation that may be germline or somatic and the second one that is always somatic. Identification of the RB1 germline status of a patient allows differentiation between sporadic and heritable retinoblastoma variants. Application of this knowledge is crucial for assessing short-term (risk of additional tumors in the same eye and other eye) and long-term (risk of nonocular malignant tumors) prognosis and offering cost-effective surveillance strategies. Genetic testing and genetic counseling are therefore essential components of care for all children diagnosed with retinoblastoma. The American Joint Committee on Cancer has acknowledged the importance of detecting this heritable trait and has introduced the letter "H" to denote a heritable trait of all cancers, starting with retinoblastoma (in publication). In this article, we discuss the clinically relevant aspects of genetic testing and genetic counseling for a child with retinoblastoma. PMID:27488068

  19. Genetics Home Reference: sialuria

    MedlinePlus

    ... conditions more common in particular ethnic groups? Genetic Changes Mutations in the GNE gene cause sialuria . The GNE gene provides instructions for making an enzyme found in cells and tissues throughout the body. This enzyme is involved in a chemical pathway that produces sialic acid, which is a ...

  20. Genetically Engineering Entomopathogenic Fungi.

    PubMed

    Zhao, H; Lovett, B; Fang, W

    2016-01-01

    Entomopathogenic fungi have been developed as environmentally friendly alternatives to chemical insecticides in biocontrol programs for agricultural pests and vectors of disease. However, mycoinsecticides currently have a small market share due to low virulence and inconsistencies in their performance. Genetic engineering has made it possible to significantly improve the virulence of fungi and their tolerance to adverse conditions. Virulence enhancement has been achieved by engineering fungi to express insect proteins and insecticidal proteins/peptides from insect predators and other insect pathogens, or by overexpressing the pathogen's own genes. Importantly, protein engineering can be used to mix and match functional domains from diverse genes sourced from entomopathogenic fungi and other organisms, producing insecticidal proteins with novel characteristics. Fungal tolerance to abiotic stresses, especially UV radiation, has been greatly improved by introducing into entomopathogens a photoreactivation system from an archaean and pigment synthesis pathways from nonentomopathogenic fungi. Conversely, gene knockout strategies have produced strains with reduced ecological fitness as recipients for genetic engineering to improve virulence; the resulting strains are hypervirulent, but will not persist in the environment. Coupled with their natural insect specificity, safety concerns can also be mitigated by using safe effector proteins with selection marker genes removed after transformation. With the increasing public concern over the continued use of synthetic chemical insecticides and growing public acceptance of genetically modified organisms, new types of biological insecticides produced by genetic engineering offer a range of environmentally friendly options for cost-effective control of insect pests.

  1. Genetics and the nephron.

    PubMed

    Marlais, M; Coward, R J

    2014-04-01

    There have been phenomenal advances in our understanding of renal biology over the last 20 years through our ability to define the genetic mutations causing kidney disease in children. This review will take you through a trip down the nephron and highlight how these conditions may present to the paediatrician and the molecular basis for their biological effects.

  2. Genetic recombination. [Escherichia coli

    SciTech Connect

    Stahl, F.W.

    1987-02-01

    The molecular pathways of gene recombination are explored and compared in studies of the model organisms, Escherichia coli and phase lambda. In the discussion of data from these studies it seems that recombination varies with the genetic idiosyncrasies of the organism and may also vary within a single organism.

  3. Genetic Technologies and Ethics

    PubMed Central

    Ardekani, Ali M.

    2009-01-01

    In the past decade, the human genome has been completely sequenced and the knowledge from it has begun to influence the fields of biological and social sciences in fundamental ways. Identification of about 25000 genes in the human genome is expected to create great benefits in diagnosis and treatment of diseases in the coming years. However, Genetic technologies have also created many interesting and difficult ethical issues which can affect the human societies now and in the future. Application of genetic technologies in the areas of stem cells, cloning, gene therapy, genetic manipulation, gene selection, sex selection and preimplantation diagnosis has created a great potential for the human race to influence and change human life on earth as we know it today. Therefore, it is important for leaders of societies in the modern world to pay attention to the advances in genetic technologies and prepare themselves and those institutions under their command to face the challenges which these new technologies induce in the areas of ethics, law and social policies. PMID:23908725

  4. [Genetic predisposition for alcoholism].

    PubMed

    Agarwal-Kozlowski, K; Agarwal, D P

    2000-04-01

    A number of socio-economic, cultural, biobehavioral factors and ethnic/gender differences are among the strongest determinants of drinking patterns in a society. Both epidemiological and clinical studies have implicated the excessive use of alcohol in the risk of developing a variety of organ, neuronal and metabolic disorders. Alcohol abuse related metabolic derangements affect almost all body organs and their functions. Race and gender differences in drinking patterns may play an important role in the development of medical conditions associated with alcohol abuse. The incidence of alcoholism in a community is influenced by per capita alcohol consumption and covariates with the relative price and availability of alcoholic drinks. The majority of the family, twin and adoption studies suggest that alcoholism is familial, a significant proportion of which can be attributed to genetic factors. The question is how much of the variance is explained by genetic factors and to what degree is this genetically mediated disorder moderated by personal characteristics. Among the most salient personal characteristics moderating, the genetic vulnerability may be factors such as age, ethnicity, and presence of psychiatric co morbidity. Cultural factors and familial environmental factors are most likely predictors as well.

  5. Genetics of alcoholism.

    PubMed

    Edenberg, Howard J; Foroud, Tatiana

    2014-01-01

    Multiple lines of evidence strongly indicate that genetic factors contribute to the risk for alcohol use disorders (AUD). There is substantial heterogeneity in AUD, which complicates studies seeking to identify specific genetic factors. To identify these genetic effects, several different alcohol-related phenotypes have been analyzed, including diagnosis and quantitative measures related to AUDs. Study designs have used candidate gene analyses, genetic linkage studies, genomewide association studies (GWAS), and analyses of rare variants. Two genes that encode enzymes of alcohol metabolism have the strongest effect on AUD: aldehyde dehydrogenase 2 and alcohol dehydrogenase 1B each has strongly protective variants that reduce risk, with odds ratios approximately 0.2-0.4. A number of other genes important in AUD have been identified and replicated, including GABRA2 and alcohol dehydrogenases 1B and 4. GWAS have identified additional candidates. Rare variants are likely also to play a role; studies of these are just beginning. A multifaceted approach to gene identification, targeting both rare and common variations and assembling much larger datasets for meta-analyses, is critical for identifying the key genes and pathways important in AUD.

  6. Demonstration: Genetic Jewelry

    ERIC Educational Resources Information Center

    Atkins, Thomas; Roderick, Joyce

    2006-01-01

    In order for students to understand genetics and evolution, they must first understand the structure of the DNA molecule. The function of DNA proceeds from its unique structure, a structure beautifully adapted for information storage, transcription, translation into amino acid sequences, replication, and time travel. The activity described in this…

  7. The new genetics

    SciTech Connect

    Jaroff, L.

    1991-01-01

    Knowing the location and make-up of each of the 50,000 to 100,000 human genes will revolutionize the practice of medicine. This knowledge will lead to tailor-made therapies not only for treating disease but also for preventing it - in short, to a new concept of patient care. The Human Genome Project, a 15-year, $3 billion quest to determine the nucleotide sequence of the entire human genome, will make this possible. In The New Genetics, Leon Jaroff recounts the long path of discovery thatt has led to this huge new scientific venture - from the theory of heredity put forth by Aristotle more than 2,000 years ago to the current attempts to treat adenosine deaminase (ADA) deficiency and malignant melanoma via gene therapy. Against this background, the geneticists, molecular biologists, clinicians, and ethicists involved in the Human Genome Project describe their work and how it will provide physicians with ever more precise and effective tools to treat human disease. Jaroff also reveals the other, more problematic side of the story. Patients with an undesirable genetic profile may be subject to discrimination by private insurers. Physicians who fail to recommend genetic screening may find themselves victims of malpractice or wrongful-life suits. Indeed, these issues and others have already begun to affect physicians. The New Genetics makes it abundantly clear tha a revolution has arrived, and that physicians must be prepared to cope with the new order.

  8. Genetic mechanisms of parenting.

    PubMed

    Mileva-Seitz, Viara R; Bakermans-Kranenburg, Marian J; van IJzendoorn, Marinus H

    2016-01-01

    This article is part of a Special Issue "Parental Care". The complexities of parenting behavior in humans have been studied for decades. Only recently did we begin to probe the genetic and epigenetic mechanisms underlying these complexities. Much of the research in this field continues to be informed by animal studies, where genetic manipulations and invasive tools allow to peek into and directly observe the brain during the expression of maternal behavior. In humans, studies of adult twins who are parents can suggest dimensions of parenting that might be more amenable to a genetic influence. Candidate gene studies can test specific genes in association with parental behavior based on prior knowledge of those genes' function. Gene-by-environment interactions of a specific kind indicating differential susceptibility to the environment might explain why some parents are more resilient and others are more vulnerable to stressful life events. Epigenetic studies can provide the bridge often necessary to explain why some individuals behave differently from others despite common genetic influences. There is a much-needed expansion in parenting research to include not only mothers as the focus-as has been the case almost exclusively to date-but also fathers, grandparents, and other caregivers.

  9. Oprelvekin. Genetics Institute.

    PubMed

    Sitaraman, S V; Gewirtz, A T

    2001-10-01

    Genetics Institute has developed and launched oprelvekin (rhIL-11; Neumega), a recombinant form of human IL-11. In November 1997, the FDA cleared oprelvekin for the prevention of severe thrombocytopenia and the reduction of the need for platelet transfusions following myelosuppressive chemotherapy in susceptible patients with non-myeloid malignancies 12703021. The product was launched at the end of 1997 [312556]. By December 1999, phase III trials for Crohn's disease (CD) were underway [363007]. Genetics Institute had commenced a 150-patient phase II trial for mild-to-moderate CD and mucositis and the company planned to file regulatory procedures for the indication of CD in 1999 [271210]. An oral formulation for this indication has been developed. Oprelvekin is also undergoing phase I clinical trials for colitis [396157], phase II clinical trials for rheumatoid arthritis [413835] and clinical trials for psoriasis [299644]. In March 1997, Wyeth-Ayerst became the licensee for Europe, Africa, Latin America and Asia (with the exception of Japan). Genetics Institute holds marketing rights for North America [239273]. In Japan, oprelvekin is being developed by Genetics Institute and Yamanouchi; phase III trials have commenced [295049] and were ongoing in May 2001 [411763]. In April 1996, analysts at Yamaichi estimated launch in 2001 and maximum annual sales of over yen 10 billion [215896]. In January 1998, Morgan Stanley Dean Witter predicted Yamanouchi's share of sales to be yen 1 billion in 2001, rising to yen 2 billion in 2002 [315458]. Sales of oprelvekin were US $34 million for Genetics institute in fiscal 2000 while, in July 2001, Credit Suisse First Boston estimated that this figure will be US $30 million and US $34 million in 2001 and 2002, respectively [416883]. PMID:11890354

  10. [Genetics and public health].

    PubMed

    Penchaszadeh, V B

    1993-07-01

    In order to draw attention to the need for public health action in genetics in Latin America, the author begins by giving a brief review of congenital anomalies, including hereditary diseases and chromosomal anomalies. He notes that these defects affect at least 5% of live births in the different regions of the world, regardless of the development status or ethnic make-up of their populations. In the Region of the Americas, birth defects rank somewhere between second and fifth place among causes of death in children under 1 year of age, and account for 2% to 27% of infant mortality. It is logical to expect that these disorders will take on more relative importance as the general indicators of child health improve, as has been the case in industrialized countries. The fact that pathologies of genetic origin affect a wide range of organs and systems, are chronic, and require expensive therapy and rehabilitation means that they demand services that countries must be prepared to provide. The author proposes three general objectives for health activities regarding genetics: to minimize clinical manifestations in individuals who are born with congenital anomalies by means of adequate care at all service levels; to improve the quality of life for those individuals and their families by helping them to become involved in the normal life of their communities; and to ensure that people at high risk of conceiving children with genetic diseases receive counseling and support services so that they can exercise their right to informed reproduction. Finally, he recommends eight strategies for setting up genetic health programs with the resources available in each country. PMID:8373531

  11. Haplosporidium littoralis sp. nov.: a crustacean pathogen within the Haplosporida (Cercozoa, Ascetosporea).

    PubMed

    Stentiford, G D; Bateman, K S; Stokes, N A; Carnegie, R B

    2013-09-01

    Previously, we described the pathology and ultrastructure of an apparently asporous haplosporidian-like parasite infecting the common shore crab Carcinus maenas from the European shoreline. In the current study, extraction of genomic DNA from the haemolymph, gill or hepatopancreas of infected C. maenas was carried out and the small subunit ribosomal DNA (SSU rDNA) of the pathogen was amplified by PCR before cloning and sequencing. All 4 crabs yielded an identical 1736 bp parasite sequence. BLAST analysis against the NCBI GenBank database identified the sequence as most similar to the protistan pathogen group comprising the order Haplosporida within the class Ascetosporea of the phylum Cercozoa Cavalier-Smith, 1998. Parsimony analysis placed the crab pathogen within the genus Haplosporidium, sister to the molluscan parasites H. montforti, H. pickfordi and H. lusitanicum. The parasite infecting C. maenas is hereby named as Haplosporidium littoralis sp. nov. The presence of a haplosporidian parasite infecting decapod crustaceans from the European shoreline with close phylogenetic affinity to previously described haplosporidians infecting molluscs is intriguing. The study provides important phylogenetic data for this relatively understudied, but commercially significant, pathogen group.

  12. Integrated biomarker responses of an estuarine invertebrate to high abiotic stress and decreased metal contamination.

    PubMed

    Rodrigues, Aurélie Pinto; Oliva-Teles, Teresa; Mesquita, Sofia Raquel; Delerue-Matos, Cristina; Guimarães, Laura

    2014-10-01

    An integrated chemical-biological effects monitoring was performed in 2010 and 2012 in two NW Iberian estuaries under different anthropogenic pressure. One is low impacted and the other is contaminated by metals. The aim was to verify the usefulness of a multibiomarker approach, using Carcinus maenas as bioindicator species, to reflect diminishing environmental contamination and improved health status under abiotic variation. Sampling sites were assessed for metal levels in sediments and C. maenas, water abiotic factors and biomarkers (neurotoxicity, energy metabolism, biotransformation, anti-oxidant defences, oxidative damage). High inter-annual and seasonal abiotic variation was observed. Metal levels in sediments and crab tissues were markedly higher in 2010 than in 2012 in the contaminated estuary. Biomarkers indicated differences between the study sites and seasons and an improvement of effects measured in C. maenas from the polluted estuary in 2012. Integrated Biomarker Response (IBR) index depicted sites with higher stress levels whereas Principal Component Analysis (PCA) showed associations between biomarker responses and environmental variables. The multibiomarker approach and integrated assessments proved to be useful to the early diagnosis of remediation measures in impacted sites. PMID:25314018

  13. Haplosporidium littoralis sp. nov.: a crustacean pathogen within the Haplosporida (Cercozoa, Ascetosporea).

    PubMed

    Stentiford, G D; Bateman, K S; Stokes, N A; Carnegie, R B

    2013-09-01

    Previously, we described the pathology and ultrastructure of an apparently asporous haplosporidian-like parasite infecting the common shore crab Carcinus maenas from the European shoreline. In the current study, extraction of genomic DNA from the haemolymph, gill or hepatopancreas of infected C. maenas was carried out and the small subunit ribosomal DNA (SSU rDNA) of the pathogen was amplified by PCR before cloning and sequencing. All 4 crabs yielded an identical 1736 bp parasite sequence. BLAST analysis against the NCBI GenBank database identified the sequence as most similar to the protistan pathogen group comprising the order Haplosporida within the class Ascetosporea of the phylum Cercozoa Cavalier-Smith, 1998. Parsimony analysis placed the crab pathogen within the genus Haplosporidium, sister to the molluscan parasites H. montforti, H. pickfordi and H. lusitanicum. The parasite infecting C. maenas is hereby named as Haplosporidium littoralis sp. nov. The presence of a haplosporidian parasite infecting decapod crustaceans from the European shoreline with close phylogenetic affinity to previously described haplosporidians infecting molluscs is intriguing. The study provides important phylogenetic data for this relatively understudied, but commercially significant, pathogen group. PMID:23999708

  14. Genetic Engineering and the Amelioration of Genetic Defect

    ERIC Educational Resources Information Center

    Lederberg, Joshua

    1970-01-01

    Discusses the claims for a brave new world of genetic manipulation" and concludes that if we could agree upon applying genetic (or any other effective) remedies to global problems we probably would need no rescourse to them. Suggests that effective methods of preventing genetic disease are prevention of mutations and detection and containment of…

  15. Genetics Home Reference: lactose intolerance

    MedlinePlus

    ... DM. Lactose digestion and the evolutionary genetics of lactase persistence. Hum Genet. 2009 Jan;124(6):579-91. ... Swallow DM, Thomas MG. A worldwide correlation of lactase persistence phenotype and genotypes. BMC Evol Biol. 2010 Feb ...

  16. Genetics Home Reference: Pompe disease

    MedlinePlus

    ... of Pompe disease: Baby's First Test GeneReview: Glycogen Storage Disease Type II (Pompe Disease) Genetic Testing Registry: Glycogen storage disease type II, infantile Genetic Testing Registry: Glycogen ...

  17. Genetics Home Reference: Northern epilepsy

    MedlinePlus

    ... Understand Genetics Home Health Conditions Northern epilepsy Northern epilepsy Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Northern epilepsy is a genetic condition that causes recurrent seizures ( ...

  18. Genetic discrimination in the workplace.

    PubMed

    Miller, P S

    1998-01-01

    Author argues that the Americans with Disabilities Act prohibits discrimination against workers based on their genetic makeup. He also examines state legislation and recently proposed federal legislation prohibiting genetic discrimination.

  19. Genetics Home Reference: frontometaphyseal dysplasia

    MedlinePlus

    ... bowed limbs, an abnormal curvature of the spine ( scoliosis ), and abnormalities of the fingers and hands. Characteristic ... and genetic heterogeneity in frontometaphyseal dysplasia: severe progressive scoliosis in two families. Am J Med Genet A. ...

  20. NCI Dictionary of Genetics Terms

    Cancer.gov

    A dictionary of more than 150 genetics-related terms written for healthcare professionals, developed to support the comprehensive, evidence-based, peer-reviewed PDQ cancer genetics information summaries.

  1. [Hereditary hearing loss: genetic counselling].

    PubMed

    Cabanillas Farpón, Rubén; Cadiñanos Bañales, Juan

    2012-01-01

    The aim of this review is to provide an updated overview of hereditary hearing loss, with special attention to the etiological diagnosis of sensorineural hearing loss, the genes most frequently mutated in our environment, the techniques available for their analysis and the clinical implications of genetic diagnosis. More than 60% of childhood sensorineural hearing loss is genetic. In adults, the percentage of hereditary hearing loss is unknown. Genetic testing is the highest yielding test for evaluating patients with sensorineural hearing loss. The process of genetic counselling is intended to inform patients and their families of the medical, psychological and familial implications of genetic diseases, as well as the risks, benefits and limitations of genetic testing. The implementation of any genetic analysis must be always preceded by an appropriate genetic counselling process.

  2. Genetic Testing and Eye Disease

    MedlinePlus

    ... a History of Eye Disease, Do You Need Genetic Testing? Mar. 23, 2012 Thanks to news coverage, ... of breast or ovarian cancer. Physicians now use genetic tests to decide on treatment for some types ...

  3. Genetic Features of Turner Syndrome

    MedlinePlus

    ... Current Studies Publications Lab Staff Contact Info Links Genetic Features Quick Navigation Introduction X-monosomy X-mosaicism ... Figure 3. X Chromosome Abnormalities Figure 4. Mosaicism Genetic Features of Turner Syndrome Turner syndrome is a ...

  4. Genetics Home Reference: diastrophic dysplasia

    MedlinePlus

    ... my area? Other Names for This Condition Diastrophic dwarfism DTD Related Information How are genetic conditions and ... 2 links) Health Topic: Bone Diseases Health Topic: Dwarfism Genetic and Rare Diseases Information Center (1 link) ...

  5. Evolutionary Genetics: Reuse, Recycle, Converge.

    PubMed

    Miller, Charles J J; Matute, Daniel R

    2016-09-26

    Our understanding of how genetic changes underlie the evolution of traits is growing fast. Two new studies now show that changes in the same genetic loci can drive the evolution of the same trait in multiple Drosophila species. PMID:27676299

  6. Genetic Screening for Employment Purposes.

    ERIC Educational Resources Information Center

    Olian, Judy D.

    1984-01-01

    Discusses genetic screening in the employment context, which involves identification of individuals hypersusceptible to toxins in the work environment. Examines the status of genetic screening devices against standard testing and legal criteria. (LLL)

  7. Selected Readings in Genetic Engineering

    ERIC Educational Resources Information Center

    Mertens, Thomas R.; Robinson, Sandra K.

    1973-01-01

    Describes different sources of readings for understanding issues and concepts of genetic engineering. Broad categories of reading materials are: concerns about genetic engineering; its background; procedures; and social, ethical and legal issues. References are listed. (PS)

  8. Thoughts on Human Genetics Education.

    ERIC Educational Resources Information Center

    Epstein, Charles J.

    1980-01-01

    The director of the Birth Defects Center at the University of California at San Francisco addresses the reasons for developing good ways of teaching human genetics. Genetic counseling is discussed within the context of several case histories. (SA)

  9. Genetics Home Reference: Silver syndrome

    MedlinePlus

    ... Me Understand Genetics Home Health Conditions Silver syndrome Silver syndrome Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Silver syndrome belongs to a group of genetic disorders ...

  10. Genetics Home Reference: adiposis dolorosa

    MedlinePlus

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions adiposis dolorosa adiposis dolorosa Enable ...

  11. Genetics Home Reference: Canavan disease

    MedlinePlus

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions Canavan disease Canavan disease Enable ...

  12. Genetics Home Reference: Carney complex

    MedlinePlus

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions Carney complex Carney complex Enable ...

  13. Genetics Home Reference: cardiofaciocutaneous syndrome

    MedlinePlus

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions cardiofaciocutaneous syndrome cardiofaciocutaneous syndrome Enable ...

  14. Genetics Home Reference: Caffey disease

    MedlinePlus

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions Caffey disease Caffey disease Enable ...

  15. Genetics Home Reference: Blau syndrome

    MedlinePlus

    ... inherited version of the disorder called early-onset sarcoidosis. Related Information What does it mean if a ... Genetic Testing Registry: Blau syndrome Genetic Testing Registry: Sarcoidosis, early-onset Merck Manual Consumer Version: Overview of ...

  16. Genetics Home Reference: Feingold syndrome

    MedlinePlus

    ... Brunner HG. Feingold syndrome: clinical review and genetic mapping. Am J Med Genet A. 2003 Nov 1; ... Brunner HG. MYCN haploinsufficiency is associated with reduced brain size and intestinal atresias in Feingold syndrome. Nat ...

  17. [Genetic information and future medicine].

    PubMed

    Sakurai, Akihiro

    2012-11-01

    Rapid technological advances in genetic analysis have revealed the genetic background of various diseases. Elucidation of the genes responsible for a disease enables better clinical management of the disease and helps to develop targeted drugs. Also, early diagnosis and management of at-risk family members can be made by identification of a genetic disease in the proband. On the other hand, genetic issues often cause psychological distress to the family. To perform genetic testing appropriately and to protect patients and family members from any harm, guidelines for genetic testing were released from the alliance of Japanese genetics-related academic societies in 2003. As genetic testing is becoming incorporated into clinical practice more broadly, the guideline was revised and released by the Japanese Society of Medical Sciences in 2011. All medical professionals in Japan are expected to follow this guideline.

  18. Evolutionary Genetics: Reuse, Recycle, Converge.

    PubMed

    Miller, Charles J J; Matute, Daniel R

    2016-09-26

    Our understanding of how genetic changes underlie the evolution of traits is growing fast. Two new studies now show that changes in the same genetic loci can drive the evolution of the same trait in multiple Drosophila species.

  19. Genetics of bipolar disorder

    PubMed Central

    Craddock, N.; Jones, I.

    1999-01-01

    Bipolar disorder (also known as manic depressive illness) is a complex genetic disorder in which the core feature is pathological disturbance in mood (affect) ranging from extreme elation, or mania, to severe depression usually accompanied by disturbances in thinking and behaviour. The lifetime prevalence of 1% is similar in males and females and family, twin, and adoption studies provide robust evidence for a major genetic contribution to risk. There are methodological impediments to precise quantification, but the approximate lifetime risk of bipolar disorder in relatives of a bipolar proband are: monozygotic co-twin 40-70%; first degree relative 5-10%; unrelated person 0.5-1.5%. Occasional families may exist in which a single gene plays the major role in determining susceptibility, but the majority of bipolar disorder involves the interaction of multiple genes (epistasis) or more complex genetic mechanisms (such as dynamic mutation or imprinting). Molecular genetic positional and candidate gene approaches are being used for the genetic dissection of bipolar disorder. No gene has yet been identified but promising findings are emerging. Regions of interest identified in linkage studies include 4p16, 12q23-q24, 16p13, 21q22, and Xq24-q26. Chromosome 18 is also of interest but the findings are confusing with up to three possible regions implicated. To date most candidate gene studies have focused on neurotransmitter systems influenced by medication used in clinical management of the disorder but no robust positive findings have yet emerged. It is, however, almost certain that over the next few years bipolar susceptibility genes will be identified. This will have a major impact on our understanding of disease pathophysiology and will provide important opportunities to investigate the interaction between genetic and environmental factors involved in pathogenesis. This is likely to lead to major improvements in treatment and patient care but will also raise important

  20. Advances in genetics. Volume 23

    SciTech Connect

    Caspari, E.W.; Scandalios, J.G.

    1985-01-01

    This book presents articles on genetics and the advances made in this field. Topics covered include the following: recovery, repair, and mutagenesis in Schizosaccharomyces pombe; gene transfer in fungi; Y chromosome function and spermatogenesis in Drosophila hydei; recent developments in population genetics; and genetics, cytology and evolution of Gossypium.

  1. Genetic Counseling in Mental Retardation.

    ERIC Educational Resources Information Center

    Bowen, Peter

    The task of the genetic counselor who identifies genetic causes of mental retardation and assists families to understand risk of recurrence is described. Considered are chromosomal genetic disorders such as Down's syndrome, inherited disorders such as Tay-Sachs disease, identification by testing the amniotic fluid cells (amniocentresis) in time…

  2. Moral Fantasy in Genetic Engineering.

    ERIC Educational Resources Information Center

    Boone, C. Keith

    1984-01-01

    Discusses the main ethical issues generated by the new genetics and suggests ways to think about them. Concerns include "playing God," violation of the natural order of the universe, and abuse of genetic technology. Critical distinctions for making difficult decisions about genetic engineering issues are noted. (DH)

  3. Genetics Home Reference: Kabuki syndrome

    MedlinePlus

    ... Hum Genet. 2012 Apr;57(4):223-7. doi: 10.1038/jhg.2012.28. Epub 2012 Mar ... Hum Genet. 2009 May;54(5):304-9. doi: 10.1038/jhg.2009.30. Epub 2009 Apr ... Genet. 2012 Jan 13;90(1):119-24. doi: 10.1016/j.ajhg.2011.11.021. Epub ...

  4. Finance issue brief: genetic testing.

    PubMed

    Herstek, J

    1999-06-25

    States have enacted genetic testing laws to address the contentious privacy, consent, research, discrimination, insurance and employment issues surrounding genetic information. These genetic testing laws attempt to strike a balance between the concerns of the consumer, research, insurance and business communities.

  5. The genetics of cancer survivorship.

    PubMed

    Allan, James M

    2008-04-01

    Constitutional (hereditary) genetic variation and somatic genetic alterations acquired during transformation to the neoplastic phenotype are both critical determinants of cancer outcome, and can ultimately have a significant effect on cancer survivorship. This article discusses the role of constitutional and somatic genetics in determining outcome and survivorship following a diagnosis of cancer using illustrative examples primarily from the hematologic malignancies. PMID:18395149

  6. Characterizing the evolution of genetic variance using genetic covariance tensors.

    PubMed

    Hine, Emma; Chenoweth, Stephen F; Rundle, Howard D; Blows, Mark W

    2009-06-12

    Determining how genetic variance changes under selection in natural populations has proved to be a very resilient problem in evolutionary genetics. In the same way that understanding the availability of genetic variance within populations requires the simultaneous consideration of genetic variance in sets of functionally related traits, determining how genetic variance changes under selection in natural populations will require ascertaining how genetic variance-covariance (G) matrices evolve. Here, we develop a geometric framework using higher-order tensors, which enables the empirical characterization of how G matrices have diverged among populations. We then show how divergence among populations in genetic covariance structure can then be associated with divergence in selection acting on those traits using key equations from evolutionary theory. Using estimates of G matrices of eight male sexually selected traits from nine geographical populations of Drosophila serrata, we show that much of the divergence in genetic variance occurred in a single trait combination, a conclusion that could not have been reached by examining variation among the individual elements of the nine G matrices. Divergence in G was primarily in the direction of the major axes of genetic variance within populations, suggesting that genetic drift may be a major cause of divergence in genetic variance among these populations.

  7. Genetic secrets: Protecting privacy and confidentiality in the genetic era

    SciTech Connect

    Rothstein, M.A.

    1998-07-01

    Few developments are likely to affect human beings more profoundly in the long run than the discoveries resulting from advances in modern genetics. Although the developments in genetic technology promise to provide many additional benefits, their application to genetic screening poses ethical, social, and legal questions, many of which are rooted in issues of privacy and confidentiality. The ethical, practical, and legal ramifications of these and related questions are explored in depth. The broad range of topics includes: the privacy and confidentiality of genetic information; the challenges to privacy and confidentiality that may be projected to result from the emerging genetic technologies; the role of informed consent in protecting the confidentiality of genetic information in the clinical setting; the potential uses of genetic information by third parties; the implications of changes in the health care delivery system for privacy and confidentiality; relevant national and international developments in public policies, professional standards, and laws; recommendations; and the identification of research needs.

  8. Genetics of athletic performance.

    PubMed

    Ostrander, Elaine A; Huson, Heather J; Ostrander, Gary K

    2009-01-01

    Performance enhancing polymorphisms (PEPs) are examples of natural genetic variation that affect the outcome of athletic challenges. Elite athletes, and what separates them from the average competitor, have been the subjects of discussion and debate for decades. While training, diet, and mental fitness are all clearly important contributors to achieving athletic success, the fact that individuals reaching the pinnacle of their chosen sports often share both physical and physiological attributes suggests a role for genetics. That multiple members of a family often participate in highly competitive events, such as the Olympics, further supports this argument. In this review, we discuss what is known regarding the genes and gene families, including the mitochondrial genome, that are believed to play a role in human athletic performance. Where possible, we describe the physiological impact of the critical gene variants and consider predictions about other potentially important genes. Finally, we discuss the implications of these findings on the future for competitive athletics. PMID:19630564

  9. Mapping human genetic ancestry.

    PubMed

    Ebersberger, Ingo; Galgoczy, Petra; Taudien, Stefan; Taenzer, Simone; Platzer, Matthias; von Haeseler, Arndt

    2007-10-01

    The human genome is a mosaic with respect to its evolutionary history. Based on a phylogenetic analysis of 23,210 DNA sequence alignments from human, chimpanzee, gorilla, orangutan, and rhesus, we present a map of human genetic ancestry. For about 23% of our genome, we share no immediate genetic ancestry with our closest living relative, the chimpanzee. This encompasses genes and exons to the same extent as intergenic regions. We conclude that about 1/3 of our genes started to evolve as human-specific lineages before the differentiation of human, chimps, and gorillas took place. This explains recurrent findings of very old human-specific morphological traits in the fossils record, which predate the recent emergence of the human species about 5-6 MYA. Furthermore, the sorting of such ancestral phenotypic polymorphisms in subsequent speciation events provides a parsimonious explanation why evolutionary derived characteristics are shared among species that are not each other's closest relatives.

  10. Chemical genetics and regeneration.

    PubMed

    Sengupta, Sumitra; Zhang, Liyun; Mumm, Jeff S

    2015-01-01

    Regeneration involves interactions between multiple signaling pathways acting in a spatially and temporally complex manner. As signaling pathways are highly conserved, understanding how regeneration is controlled in animal models exhibiting robust regenerative capacities should aid efforts to stimulate repair in humans. One way to discover molecular regulators of regeneration is to alter gene/protein function and quantify effect(s) on the regenerative process: dedifferentiation/reprograming, stem/progenitor proliferation, migration/remodeling, progenitor cell differentiation and resolution. A powerful approach for applying this strategy to regenerative biology is chemical genetics, the use of small-molecule modulators of specific targets or signaling pathways. Here, we review advances that have been made using chemical genetics for hypothesis-focused and discovery-driven studies aimed at furthering understanding of how regeneration is controlled.

  11. Genetic manipulation of Agrobacterium.

    PubMed

    Morton, Elise R; Fuqua, Clay

    2012-05-01

    Agrobacterium species are plant-associated relatives of the rhizobia. Several species cause plant diseases such as crown gall and hairy root, although there are also avirulent species. A. tumefaciens is the most intensively studied species and causes crown gall, a neoplastic disease that occurs on a variety of plants. Virulence is specified by large plasmids, and in the case of A. tumefaciens, this is called the Ti (tumor-inducing) plasmid. During pathogenesis virulent agrobacteria copy a segment of the Ti plasmid and transfer it to the plant, where it subsequently integrates into the plant genome, and expresses genes that result in the disease symptoms. A. tumefaciens has been used extensively as a plant genetic engineering tool and is also a model microorganism that has been well studied for host-microbe associations, horizontal gene transfer, cell-cell communication, and biofilm formation. This unit describes standard protocols for genetic manipulation of A. tumefaciens. PMID:22549163

  12. Pediatric genetic ocular tumors

    PubMed Central

    Rouhani, Behnaz; Ramasubramanian, Aparna

    2014-01-01

    Pediatric genetic ocular tumors include malignancies like retinoblastoma and phakomatosis like neurofibromatosis, tuberous sclerosis, von Hippel-Lindau syndrome, and nevoid basal cell carcinoma syndrome. It is important to screen for ocular tumors both for visual prognosis and also for systemic implications. The phakomatosis comprise of multitude of benign tumors that are aysmptomatic but their detection can aid in the diagnosis of the syndrome. Retinoblastoma is the most common malignant intraocular tumor in childhood and with current treatment modalities, the survival is more than 95%. It is transmitted as an autosomal dominant fashion and hence the offsprings of all patients with the germline retinoblastoma need to be screened from birth. This review discusses the various pediatric genetic ocular tumors discussing the clinical manifestation, diagnosis and treatment.

  13. "Genetically Engineered" Nanoelectronics

    NASA Technical Reports Server (NTRS)

    Klimeck, Gerhard; Salazar-Lazaro, Carlos H.; Stoica, Adrian; Cwik, Thomas

    2000-01-01

    The quantum mechanical functionality of nanoelectronic devices such as resonant tunneling diodes (RTDs), quantum well infrared-photodetectors (QWIPs), quantum well lasers, and heterostructure field effect transistors (HFETs) is enabled by material variations on an atomic scale. The design and optimization of such devices requires a fundamental understanding of electron transport in such dimensions. The Nanoelectronic Modeling Tool (NEMO) is a general-purpose quantum device design and analysis tool based on a fundamental non-equilibrium electron transport theory. NEW was combined with a parallelized genetic algorithm package (PGAPACK) to evolve structural and material parameters to match a desired set of experimental data. A numerical experiment that evolves structural variations such as layer widths and doping concentrations is performed to analyze an experimental current voltage characteristic. The genetic algorithm is found to drive the NEMO simulation parameters close to the experimentally prescribed layer thicknesses and doping profiles. With such a quantitative agreement between theory and experiment design synthesis can be performed.

  14. Genetics of osteoporosis.

    PubMed

    Urano, Tomohiko; Inoue, Satoshi

    2014-09-19

    Osteoporosis is a skeletal disease characterized by low bone mineral density (BMD) and microarchitectural deterioration of bone tissue, which increases susceptibility to fractures. BMD is a complex quantitative trait with normal distribution and seems to be genetically controlled (in 50-90% of the cases), according to studies on twins and families. Over the last 20 years, candidate gene approach and genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) that are associated with low BMD, osteoporosis, and osteoporotic fractures. These SNPs have been mapped close to or within genes including those encoding nuclear receptors and WNT-β-catenin signaling proteins. Understanding the genetics of osteoporosis will help identify novel candidates for diagnostic and therapeutic targets. PMID:25139232

  15. Stochastically driven genetic circuits

    NASA Astrophysics Data System (ADS)

    Tsimring, L. S.; Volfson, D.; Hasty, J.

    2006-06-01

    Transcriptional regulation in small genetic circuits exhibits large stochastic fluctuations. Recent experiments have shown that a significant fraction of these fluctuations is caused by extrinsic factors. In this paper we review several theoretical and computational approaches to modeling of small genetic circuits driven by extrinsic stochastic processes. We propose a simplified approach to this problem, which can be used in the case when extrinsic fluctuations dominate the stochastic dynamics of the circuit (as appears to be the case in eukaryots). This approach is applied to a model of a single nonregulated gene that is driven by a certain gating process that affects the rate of transcription, and to a simplified version of the galactose utilization circuit in yeast.

  16. Advances in human genetics

    SciTech Connect

    Harris, H.; Hirschhorn, K.

    1993-01-01

    This book has five chapters covering peroxisomal diseases, X-linked immunodeficiencies, genetic mutations affecting human lipoproteins and their receptors and enzymes, genetic aspects of cancer, and Gaucher disease. The chapter on peroxisomes covers their discovery, structure, functions, disorders, etc. The chapter on X-linked immunodeficiencies discusses such diseases as agammaglobulinemia, severe combined immunodeficiency, Wiskott-Aldrich syndrome, animal models, linkage analysis, etc. Apolipoprotein formation, synthesis, gene regulation, proteins, etc. are the main focus of chapter 3. The chapter on cancer covers such topics as oncogene mapping and the molecular characterization of some recessive oncogenes. Gaucher disease is covered from its diagnosis, classification, and prevention, to its organ system involvement and molecular biology.

  17. Genetics of impulsive behaviour

    PubMed Central

    Bevilacqua, Laura; Goldman, David

    2013-01-01

    Impulsivity, defined as the tendency to act without foresight, comprises a multitude of constructs and is associated with a variety of psychiatric disorders. Dissecting different aspects of impulsive behaviour and relating these to specific neurobiological circuits would improve our understanding of the etiology of complex behaviours for which impulsivity is key, and advance genetic studies in this behavioural domain. In this review, we will discuss the heritability of some impulsivity constructs and their possible use as endophenotypes (heritable, disease-associated intermediate phenotypes). Several functional genetic variants associated with impulsive behaviour have been identified by the candidate gene approach and re-sequencing, and whole genome strategies can be implemented for discovery of novel rare and common alleles influencing impulsivity. Via deep sequencing an uncommon HTR2B stop codon, common in one population, was discovered, with implications for understanding impulsive behaviour in both humans and rodents and for future gene discovery. PMID:23440466

  18. The genetics of otosclerosis.

    PubMed

    Ealy, Megan; Smith, Richard J H

    2010-07-01

    Otosclerosis is a common form of conductive hearing loss with a prevalence of 0.3-0.4% in white adults. It is characterized by labyrinthine endochondral sclerosis which may invade the stapedio-vestibular joint and interfere with free motion of the stapes. Both environmental factors and genetic causes have been implicated in the disease process; however, the pathogenesis of otosclerosis still remains poorly understood. To date, several loci have been mapped in families segregating autosomal dominant otosclerosis although no disease-causing mutations have been identified. In contrast, several association studies have implicated specific genes but their effects on risk-of-disease are small. The goal of this paper is to review the genetics of otosclerosis and to provide insight into studies that could be performed to elucidate disease pathogenesis.

  19. Genetics of schizophrenia.

    PubMed

    Escudero, Irene; Johnstone, Mandy

    2014-11-01

    The genetic basis of schizophrenia has been a hotly debated research topic for decades, yet recent studies, especially in the past year, have confirmed genetics as the major cause of this complex condition. Psychiatry has come of age: it is perhaps more difficult for the current generation of psychiatrists, to comprehend how the biological root of the condition could have been denied for so long. Here we review how highly collaborative global efforts to pool samples, utilise the very latest advances in genotyping and high throughput sequencing technologies, and application of robust statistical analysis have reaped phenomenal rewards. The major findings are that schizophrenia is a highly polygenic disorder with a complex array of risk loci, many include genes implicated also in intellectual disability, autism spectrum disorders, bipolar disorder and major depressive disorder. These candidate genes converge on key neuronal signalling pathways identifying novel targets for potential future therapeutic intervention.

  20. Genetics of athletic performance.

    PubMed

    Ostrander, Elaine A; Huson, Heather J; Ostrander, Gary K

    2009-01-01

    Performance enhancing polymorphisms (PEPs) are examples of natural genetic variation that affect the outcome of athletic challenges. Elite athletes, and what separates them from the average competitor, have been the subjects of discussion and debate for decades. While training, diet, and mental fitness are all clearly important contributors to achieving athletic success, the fact that individuals reaching the pinnacle of their chosen sports often share both physical and physiological attributes suggests a role for genetics. That multiple members of a family often participate in highly competitive events, such as the Olympics, further supports this argument. In this review, we discuss what is known regarding the genes and gene families, including the mitochondrial genome, that are believed to play a role in human athletic performance. Where possible, we describe the physiological impact of the critical gene variants and consider predictions about other potentially important genes. Finally, we discuss the implications of these findings on the future for competitive athletics.

  1. On genetic map functions

    SciTech Connect

    Zhao, Hongyu; Speed, T.P.

    1996-04-01

    Various genetic map functions have been proposed to infer the unobservable genetic distance between two loci from the observable recombination fraction between them. Some map functions were found to fit data better than others. When there are more than three markers, multilocus recombination probabilities cannot be uniquely determined by the defining property of map functions, and different methods have been proposed to permit the use of map functions to analyze multilocus data. If for a given map function, there is a probability model for recombination that can give rise to it, then joint recombination probabilities can be deduced from this model. This provides another way to use map functions in multilocus analysis. In this paper we show that stationary renewal processes give rise to most of the map functions in the literature. Furthermore, we show that the interevent distributions of these renewal processes can all be approximated quite well by gamma distributions. 43 refs., 4 figs.

  2. Genetics of Aedes albopictus.

    PubMed

    Rai, K S

    1986-12-01

    Aedes albopictus is an important vector of dengue fever and dengue hemorrhagic fever in Southeast Asia. Its distribution extends from Madagascar to Hawaii and is currently expanding. From its proposed origin in Southeast Asia, Ae. albopictus has migrated as far as Mauritius and Madagascar to the west and Korea, Japan, Guam, Hawaii and other Pacific Islands to the east. In the continental United States, it was originally reported in the Texas area in August 1985 and is now well established in several states. This paper reviews information on distribution, cytology and genetics of Aedes albopictus. In addition, it includes comments on its competitive interaction with several other species. Relevant information on evolutionary genetics of certain other related sibling species is also included for comparative purposes.

  3. Reverse genetics of mononegavirales.

    PubMed

    Conzelmann, K K

    2004-01-01

    "Reverse genetics" or de novo synthesis of nonsegmented negative-sense RNA viruses (Mononegavirales) from cloned cDNA has become a reliable technique to study this group of medically important viruses. Since the first generation of a negative-sense RNA virus entirely from cDNA in 1994, reverse genetics systems have been established for members of most genera of the Rhabdo-, Paramyxo-, and Filoviridae families. These systems are based on intracellular transcription of viral full-length RNAs and simultaneous expression of viral proteins required to form the typical viral ribonucleoprotein complex (RNP). These systems are powerful tools to study all aspects of the virus life cycle as well as the roles of virus proteins in virus-host interplay and pathogenicity. In addition, recombinant viruses can be designed to have specific properties that make them attractive as biotechnological tools and live vaccines. PMID:15298166

  4. Genetic discrimination: international perspectives.

    PubMed

    Otlowski, M; Taylor, S; Bombard, Y

    2012-01-01

    Genetic discrimination (GD) is a complex, multifaceted ethical, psychosocial, and legal phenomenon. It is defined as the differential treatment of asymptomatic individuals or their relatives on the basis of their real or assumed genetic characteristics. This article presents an overview of GD within the contemporary international context. It describes the concept of GD and its contextual features, reviews research evidence regarding people's experiences of GD and the impact of GD within a range of domains, and provides an overview of legal and policy responses to GD that have emerged globally. We argue that GD is a significant and internationally established phenomenon that requires multilevel responses to ensure social justice and equitable outcomes for all citizens. Future research should monitor GD and its impacts within the community as well as institutions and should evaluate the effectiveness of legislative, policy, community education, and systemic responses. PMID:22607273

  5. Genetic Analysis in Neurology

    PubMed Central

    Pittman, Alan; Hardy, John

    2014-01-01

    In recent years, neurogenetics research had made some remarkable advances owing to the advent of genotyping arrays and next-generation sequencing. These improvements to the technology have allowed us to determine the whole-genome structure and its variation and to examine its effect on phenotype in an unprecedented manner. The identification of rare disease-causing mutations has led to the identification of new biochemical pathways and has facilitated a greater understanding of the etiology of many neurological diseases. Furthermore, genome-wide association studies have provided information on how common genetic variability impacts on the risk for the development of various complex neurological diseases. Herein, we review how these technological advances have changed the approaches being used to study the genetic basis of neurological disease and how the research findings will be translated into clinical utility. PMID:23571731

  6. Pediatric genetic ocular tumors.

    PubMed

    Rouhani, Behnaz; Ramasubramanian, Aparna

    2014-12-01

    Pediatric genetic ocular tumors include malignancies like retinoblastoma and phakomatosis like neurofibromatosis, tuberous sclerosis, von Hippel-Lindau syndrome, and nevoid basal cell carcinoma syndrome. It is important to screen for ocular tumors both for visual prognosis and also for systemic implications. The phakomatosis comprise of multitude of benign tumors that are aysmptomatic but their detection can aid in the diagnosis of the syndrome. Retinoblastoma is the most common malignant intraocular tumor in childhood and with current treatment modalities, the survival is more than 95%. It is transmitted as an autosomal dominant fashion and hence the offsprings of all patients with the germline retinoblastoma need to be screened from birth. This review discusses the various pediatric genetic ocular tumors discussing the clinical manifestation, diagnosis and treatment. PMID:27625882

  7. Genetically engineered probiotics.

    PubMed

    Steidler, Lothar

    2003-10-01

    Probiotic micro-organisms have been used for many years. Originating as food supplements, they are now most often administered orally and offer an attractive alternative for treating of intestinal disorders. A better understanding of the mechanisms by which these micro-organisms act has now opened up possibilities for designing new probiotic strains. Through genetic engineering, it is possible not only to strengthen the effects of existing strains, but also to create completely new probiotics. These need not necessarily be composed only of bacterial products but can also include elements of regulatory systems or enzymes derived from a foreign-human-source. If designed carefully and with absolute attention to biological safety in its broadest sense, the development of genetically modified probiotics has the potential to revolutionize alimentary health.

  8. Genetics of complex diseases.

    PubMed

    Motulsky, Arno G

    2006-02-01

    Approaches to the study of the genetic basis of common complex diseases and their clinical applications are considered. Monogenic Mendelian inheritance in such conditions is infrequent but its elucidation may help to detect pathogenic mechanisms in the more common variety of complex diseases. Involvement by multiple genes in complex diseases usually occurs but the isolation and identification of specific genes so far has been exceptional. The role of common polymorphisms as indicators of disease risk in various studies is discussed.

  9. Genetics of Congenital Cataract.

    PubMed

    Pichi, Francesco; Lembo, Andrea; Serafino, Massimiliano; Nucci, Paolo

    2016-01-01

    Congenital cataract is a type of cataract that presents at birth or during early childhood, and it is one of the most easily treatable causes of visual impairment and blindness during infancy, with an estimated prevalence of 1-6 cases per 10,000 live births. Approximately 50% of all congenital cataract cases may have a genetic cause, and such cases are quite heterogeneous. Although congenital nuclear cataract can be caused by multiple factors, genetic mutation remains the most common cause. All three types of Mendelian inheritance have been reported for cataract; however, autosomal dominant transmission seems to be the most frequent. The transparency and high refractive index of the lens are achieved by the precise architecture of fiber cells and homeostasis of the lens proteins in terms of their concentrations, stabilities, and supramolecular organization. Research on hereditary congenital cataract has led to the identification of several classes of candidate genes that encode proteins such crystallins, lens-specific connexins, aquaporin, cytoskeletal structural proteins, and developmental regulators. In this review, we highlight the identified genetic mutations that account for congenital nuclear cataract.

  10. Genetics of Borrelia burgdorferi

    PubMed Central

    Brisson, Dustin; Drecktrah, Dan; Eggers, Christian H.; Samuels, D. Scott

    2013-01-01

    The spirochetes in the Borrelia burgdorferi sensu lato genospecies group cycle in nature between tick vectors and vertebrate hosts. The current assemblage of B. burgdorferi sensu lato, of which three species cause Lyme disease in humans, originated from a rapid species radiation that occurred near the origin of the clade. All of these species share a unique genome structure that is highly segmented and predominantly composed of linear replicons. One of the circular plasmids is a prophage that exists as several isoforms in each cell and can be transduced to other cells, likely contributing to an otherwise relatively anemic level of horizontal gene transfer, which nevertheless appears to be adequate to permit strong natural selection and adaptation in populations of B. burgdorferi. Although the molecular genetic toolbox is meager, several antibiotic-resistant mutants have been isolated, and the resistance alleles, as well as some exogenous genes, have been fashioned into markers to dissect gene function. Genetic studies have probed the role of the outer membrane lipoprotein OspC, which is maintained in nature by multiple niche polymorphisms and negative frequency-dependent selection. One of the most intriguing genetic systems in B. burgdorferi is vls recombination, which generates antigenic variation during infection of mammalian hosts. PMID:22974303

  11. Genetics of Allergic Diseases

    PubMed Central

    Ortiz, Romina A.; Barnes, Kathleen C.

    2015-01-01

    The allergic diseases are complex phenotypes for which a strong genetic basis has been firmly established. Genome-wide association studies (GWAS) has been widely employed in the field of allergic disease, and to date significant associations have been published for nearly 100 asthma genes/loci, in addition to multiple genes/loci for AD, AR and IgE levels, for which the overwhelming number of candidates are novel and have given a new appreciation for the role of innate as well as adaptive immune-response genes in allergic disease. A major outcome of GWAS in allergic disease has been the formation of national and international collaborations leading to consortia meta-analyses, and an appreciation for the specificity of genetic associations to sub-phenotypes of allergic disease. Molecular genetics has undergone a technological revolution, leading to next generation sequencing (NGS) strategies that are increasingly employed to hone in on the causal variants associated with allergic diseases. Unmet needs in the field include the inclusion of ethnically and racially diverse cohorts, and strategies for managing ‘big data’ that is an outcome of technological advances such as sequencing. PMID:25459575

  12. Darwin and Genetics

    PubMed Central

    Charlesworth, Brian; Charlesworth, Deborah

    2009-01-01

    Darwin's theory of natural selection lacked an adequate account of inheritance, making it logically incomplete. We review the interaction between evolution and genetics, showing how, unlike Mendel, Darwin's lack of a model of the mechanism of inheritance left him unable to interpret his own data that showed Mendelian ratios, even though he shared with Mendel a more mathematical and probabilistic outlook than most biologists of his time. Darwin's own “pangenesis” model provided a mechanism for generating ample variability on which selection could act. It involved, however, the inheritance of characters acquired during an organism's life, which Darwin himself knew could not explain some evolutionary situations. Once the particulate basis of genetics was understood, it was seen to allow variation to be passed intact to new generations, and evolution could then be understood as a process of changes in the frequencies of stable variants. Evolutionary genetics subsequently developed as a central part of biology. Darwinian principles now play a greater role in biology than ever before, which we illustrate with some examples of studies of natural selection that use DNA sequence data and with some recent advances in answering questions first asked by Darwin. PMID:19933231

  13. Clinical mitochondrial genetics

    PubMed Central

    Chinnery, P.; Howell, N.; Andrews, R.; Turnbull, D.

    1999-01-01

    The last decade has been an age of enlightenment as far as mitochondrial pathology is concerned. Well established nuclear genetic diseases, such as Friedreich's ataxia,12 Wilson disease,3 and autosomal recessive hereditary spastic paraplegia,4 have been shown to have a mitochondrial basis, and we are just starting to unravel the complex nuclear genetic disorders which directly cause mitochondrial dysfunction (table 1). However, in addition to the 3 billion base pair nuclear genome, each human cell typically contains thousands of copies of a small, 16.5 kb circular molecule of double stranded DNA (fig 1). Mitochondrial DNA (mtDNA) accounts for only 1% of the total cellular nucleic acid content. It encodes for 13 polypeptides which are essential for aerobic metabolism and defects of the mitochondrial genome are an important cause of human disease.9293 Since the characterisation of the first pathogenic mtDNA defects in 1988,513 over 50 point mutations and well over 100 rearrangements of the mitochondrial genome have been associated with human disease9495 (http://www.gen.emory.edu/mitomap.html). These disorders form the focus of this article.


Keywords: mitochondrial DNA; mitochondrial disease; heteroplasmy; genetic counselling PMID:10874629

  14. Genetics of osteoporosis

    SciTech Connect

    Urano, Tomohiko; Inoue, Satoshi

    2014-09-19

    Highlights: • Single-nucleotide polymorphisms (SNPs) associated with osteoporosis were identified. • SNPs mapped close to or within VDR and ESR1 are associated with bone mineral density. • WNT signaling pathway plays a pivotal role in regulating bone mineral density. • Genetic studies will be useful for identification of new therapeutic targets. - Abstract: Osteoporosis is a skeletal disease characterized by low bone mineral density (BMD) and microarchitectural deterioration of bone tissue, which increases susceptibility to fractures. BMD is a complex quantitative trait with normal distribution and seems to be genetically controlled (in 50–90% of the cases), according to studies on twins and families. Over the last 20 years, candidate gene approach and genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) that are associated with low BMD, osteoporosis, and osteoporotic fractures. These SNPs have been mapped close to or within genes including those encoding nuclear receptors and WNT-β-catenin signaling proteins. Understanding the genetics of osteoporosis will help identify novel candidates for diagnostic and therapeutic targets.

  15. Genetic bases for glaucoma.

    PubMed

    Fuse, Nobuo

    2010-05-01

    Glaucoma is the leading cause of visual impairment and blindness throughout the world. Primary open angle glaucoma (POAG; MIM 137760) is the main type of glaucoma in most populations, and more than 20 genetic loci for POAG have been reported. Only three causative genes have been identified in these loci, viz. myocilin (MYOC), optineurin (OPTN), and WD repeat domain 36 (WDR36). However, mutations in these genes account for only a small percentage of the patients with POAG. Some of these glaucoma cases have a Mendelian inheritance pattern, and a considerable fraction of the cases result from a large number of variants in several genes each contributing small effects. Glaucoma is considered to be a common disease such as diabetes mellitus, coronary disease, Crohn disease, and several( )common cancers. The main technological approaches used to identify the genes associated with glaucoma are the candidate gene approach, linkage analysis, case-control association study, and genome-wide association study. Association studies have found about 27 genes related to POAG, but the glaucoma-causing effects of these genes need to be investigated in more detail. The current trend is to use case-control association studies or genome-wide association studies to map the genes associated with glaucoma. Such studies are expected to greatly advance our understanding of the genetic basis of glaucoma, and to provide information on the effectiveness of glaucoma therapy. This review gives an overview on the genetic aspects of glaucoma.

  16. Genetics of inherited cardiomyopathy

    PubMed Central

    Jacoby, Daniel; McKenna, William J.

    2012-01-01

    During the past two decades, numerous disease-causing genes for different cardiomyopathies have been identified. These discoveries have led to better understanding of disease pathogenesis and initial steps in the application of mutation analysis in the evaluation of affected individuals and their family members. As knowledge of the genetic abnormalities, and insight into cellular and organ biology has grown, so has appreciation of the level of complexity of interaction between genotype and phenotype across disease states. What were initially thought to be one-to-one gene-disease correlates have turned out to display important relational plasticity dependent in large part on the genetic and environmental backgrounds into which the genes of interest express. The current state of knowledge with regard to genetics of cardiomyopathy represents a starting point to address the biology of disease, but is not yet developed sufficiently to supplant clinically based classification systems or, in most cases, to guide therapy to any significant extent. Future work will of necessity be directed towards elucidation of the biological mechanisms of both rare and common gene variants and environmental determinants of plasticity in the genotype–phenotype relationship with the ultimate goal of furthering our ability to identify, diagnose, risk stratify, and treat this group of disorders which cause heart failure and sudden death in the young. PMID:21810862

  17. Metaphors in behavioral genetics.

    PubMed

    Nordgren, A

    2003-01-01

    Behavioral geneticists sometimes use metaphors to describe the role of genes in human behavior. In this paper, five sample texts are analyzed: a popular book, a textbook, a scientific review article, and two original scientific articles representing different approaches in behavioral genetics. Metaphors are found in all the different kinds of sample texts, not only in the popular book and the textbook. This suggests that metaphors are used not only for rhetorical or pedagogical purposes but play a more fundamental role in scientific understanding. In the sample texts, the metaphors tend to be antideterministic, i.e., they do not imply genetic determinism but stress the interaction of multiple genes and multiple environmental factors. No conclusion can be drawn, however, as to whether antideterminism is representative of present-day behavioral geneticists in general. Certain historically important metaphors that may imply genetic determinism are qualified, avoided, or explicitly rejected. There are tensions between some of the metaphors, making them difficult to combine. All the metaphors that are used appear empirically apt, however sometimes only with certain qualifications. PMID:12735490

  18. Genetic Algorithms and Local Search

    NASA Technical Reports Server (NTRS)

    Whitley, Darrell

    1996-01-01

    The first part of this presentation is a tutorial level introduction to the principles of genetic search and models of simple genetic algorithms. The second half covers the combination of genetic algorithms with local search methods to produce hybrid genetic algorithms. Hybrid algorithms can be modeled within the existing theoretical framework developed for simple genetic algorithms. An application of a hybrid to geometric model matching is given. The hybrid algorithm yields results that improve on the current state-of-the-art for this problem.

  19. Clinical Genetic Testing in Gastroenterology

    PubMed Central

    Goodman, Russell P; Chung, Daniel C

    2016-01-01

    Rapid advances in genetics have led to an increased understanding of the genetic determinants of human disease, including many gastrointestinal (GI) disorders. Coupled with a proliferation of genetic testing services, this has resulted in a clinical landscape where commercially available genetic tests for GI disorders are now widely available. In this review, we discuss the current status of clinical genetic testing for GI illnesses, review the available testing options, and briefly discuss indications for and practical aspects of such testing. Our goal is to familiarize the practicing gastroenterologist with this rapidly changing and important aspect of clinical care. PMID:27124700

  20. The synthesis paradigm in genetics.

    PubMed

    Rice, William R

    2014-02-01

    Experimental genetics with model organisms and mathematically explicit genetic theory are generally considered to be the major paradigms by which progress in genetics is achieved. Here I argue that this view is incomplete and that pivotal advances in genetics--and other fields of biology--are also made by synthesizing disparate threads of extant information rather than generating new information from experiments or formal theory. Because of the explosive expansion of information in numerous "-omics" data banks, and the fragmentation of genetics into numerous subdisciplines, the importance of the synthesis paradigm will likely expand with time.

  1. Frequently Asked Questions about Genetic Disorders

    MedlinePlus

    ... used on this page Frequently Asked Questions About Genetic Disorders What are genetic disorders? A genetic disorder is a disease caused ... significant risk of developing the disease. . Geneticists group genetic disorders into three categories: Monogenetic disorders are caused ...

  2. How Are Genetic Conditions Treated or Managed?

    MedlinePlus

    ... are genetic conditions treated or managed? How are genetic conditions treated or managed? Many genetic disorders result ... out more about the treatment and management of genetic conditions: Links to information about the treatment of ...

  3. Behavioral genetics and child temperament.

    PubMed

    Saudino, Kimberly J

    2005-06-01

    Most temperament theories presume a biological basis to those behavioral tendencies thought to be temperamental in origin. Behavioral genetic methods can be used to test this assumption. Twin and adoption studies suggest that individual differences in infant and child temperament are genetically influenced. However, behavioral genetics has much more to offer to the study of temperament than simple heritability estimates. The present paper describes some recent findings from behavioral genetics research in temperament that go well beyond the basic nature-nurture question. These findings include the importance of nonshared environmental influences on temperament, genetic continuity and environmental change during development, links between temperament and behavior problems, and harnessing the power of molecular genetics to identify specific genes responsible for genetic influence on early temperament.

  4. Legal issues associated with genetics.

    PubMed

    Carson, W Y

    2000-09-01

    With the evolution of genetic research, legal issues have emerged related to the health care delivery industry and the protection of patient information. The use of genetics or genetic enhancement expands the role of the nurse and also brings a new perspective to the nurse-patient relationship. Nurses now must discern their role in relation to patient privacy and confidentiality. In addition to reviewing the ethical and legal dilemmas of registered nurses in clinical practice, the nursing profession must review the level of responsibility appropriate when using genetic and or experimental treatments, especially when the nurse is not the primary care provider or the leader of the research team. Nurses will have to delve into privacy and confidentiality issues associated with genetic research. Although little case law exists on the relationship of nursing to genetic research and treatments, the implications of experimental research and policy associated with genetics must be analyzed to better understand their impact on the scope of nursing practice.

  5. [Protective management for genetic information].

    PubMed

    Niikawa, Norio

    2005-03-01

    With advances in genomic and genetic medicine, genomic information is being used for the management of disorders. In addition, personalized medicine will be in practice in the near future. Because genetic information, i.e., disease diagnosis, gene mutations, and/or nucleotide sequences, remains unchanged through an individual's life, there are important issues for discussion, such as informed consent at sampling, protection of an individual's genetic information from any social discrimination, handling of samples, and genetic counseling. In this review, how to protect and manage the genetic information at researching and at medical practice, together with several bioethical guidelines regarding such issues, are described. A triangle system in which sample donators, directing physicians/researchers and genetic counselors participate, to manage genetic information appropriately, is also proposed.

  6. Canine epilepsy genetics.

    PubMed

    Ekenstedt, Kari J; Patterson, Edward E; Mickelson, James R

    2012-02-01

    There has been much interest in utilizing the dog as a genetic model for common human diseases. Both dogs and humans suffer from naturally occurring epilepsies that share many clinical characteristics. Investigations of inherited human epilepsies have led to the discovery of several mutated genes involved in this disease; however, the vast majority of human epilepsies remain unexplained. Mouse models of epilepsy exist, including single-gene spontaneous and knockout models, but, similar to humans, other, polygenic models have been more difficult to discern. This appears to also be the case in canine epilepsy genetics. There are two forms of canine epilepsies for which gene mutations have been described to date: the progressive myoclonic epilepsies (PMEs) and idiopathic epilepsy (IE). Gene discovery in the PMEs has been more successful, with eight known genes; six of these are orthologous to corresponding human disorders, while two are novel genes that can now be used as candidates for human studies. Only one IE gene has been described in dogs, an LGI2 mutation in Lagotto Romagnolos with a focal, juvenile remitting epilepsy. This gene is also a novel candidate for human remitting childhood epilepsy studies. The majority of studies of dog breeds with IE, however, have either failed to identify any genes or loci of interest, or, as in complex mouse and human IEs, have identified multiple QTLs. There is still tremendous promise in the ongoing canine epilepsy studies, but if canine IEs prove to be as genetically complex as human and murine IEs, then deciphering the bases of these canine epilepsies will continue to be challenging.

  7. Behavior genetics and postgenomics.

    PubMed

    Charney, Evan

    2012-10-01

    The science of genetics is undergoing a paradigm shift. Recent discoveries, including the activity of retrotransposons, the extent of copy number variations, somatic and chromosomal mosaicism, and the nature of the epigenome as a regulator of DNA expressivity, are challenging a series of dogmas concerning the nature of the genome and the relationship between genotype and phenotype. According to three widely held dogmas, DNA is the unchanging template of heredity, is identical in all the cells and tissues of the body, and is the sole agent of inheritance. Rather than being an unchanging template, DNA appears subject to a good deal of environmentally induced change. Instead of identical DNA in all the cells of the body, somatic mosaicism appears to be the normal human condition. And DNA can no longer be considered the sole agent of inheritance. We now know that the epigenome, which regulates gene expressivity, can be inherited via the germline. These developments are particularly significant for behavior genetics for at least three reasons: First, epigenetic regulation, DNA variability, and somatic mosaicism appear to be particularly prevalent in the human brain and probably are involved in much of human behavior; second, they have important implications for the validity of heritability and gene association studies, the methodologies that largely define the discipline of behavior genetics; and third, they appear to play a critical role in development during the perinatal period and, in particular, in enabling phenotypic plasticity in offspring. I examine one of the central claims to emerge from the use of heritability studies in the behavioral sciences, the principle of minimal shared maternal effects, in light of the growing awareness that the maternal perinatal environment is a critical venue for the exercise of adaptive phenotypic plasticity. This consideration has important implications for both developmental and evolutionary biology.

  8. Coalgebraic structure of genetic inheritance.

    PubMed

    Tian, Jianjun; Li, Bai-Lian

    2004-09-01

    Although in the broadly defined genetic algebra, multiplication suggests a forward direction of from parents to progeny, when looking from the reverse direction, it also suggests to us a new algebraic structure-coalge- braic structure, which we call genetic coalgebras. It is not the dual coalgebraic structure and can be used in the construction of phylogenetic trees. Math- ematically, to construct phylogenetic trees means we need to solve equations x([n]) = a, or x([n]) = b. It is generally impossible to solve these equations inalgebras. However, we can solve them in coalgebras in the sense of tracing back for their ancestors. A thorough exploration of coalgebraic structure in genetics is apparently necessary. Here, we develop a theoretical framework of the coalgebraic structure of genetics. From biological viewpoint, we defined various fundamental concepts and examined their elementary properties that contain genetic significance. Mathematically, by genetic coalgebra, we mean any coalgebra that occurs in genetics. They are generally noncoassociative and without counit; and in the case of non-sex-linked inheritance, they are cocommutative. Each coalgebra with genetic realization has a baric property. We have also discussed the methods to construct new genetic coalgebras, including cocommutative duplication, the tensor product, linear combinations and the skew linear map, which allow us to describe complex genetic traits. We also put forward certain theorems that state the relationship between gametic coalgebra and gametic algebra. By Brower's theorem in topology, we prove the existence of equilibrium state for the in-evolution operator. PMID:20369970

  9. Genetic architecture of colorectal cancer.

    PubMed

    Peters, Ulrike; Bien, Stephanie; Zubair, Niha

    2015-10-01

    Colorectal cancer (CRC) is a complex disease that develops as a consequence of both genetic and environmental risk factors. A small proportion (3-5%) of cases arise from hereditary syndromes predisposing to early onset CRC as a result of mutations in over a dozen well defined genes. In contrast, CRC is predominantly a late onset 'sporadic' disease, developing in individuals with no obvious hereditary syndrome. In recent years, genome wide association studies have discovered that over 40 genetic regions are associated with weak effects on sporadic CRC, and it has been estimated that increasingly large genome wide scans will identify many additional novel genetic regions. Subsequent experimental validations have identified the causally related variant(s) in a limited number of these genetic regions. Further biological insight could be obtained through ethnically diverse study populations, larger genetic sequencing studies and development of higher throughput functional experiments. Along with inherited variation, integration of the tumour genome may shed light on the carcinogenic processes in CRC. In addition to summarising the genetic architecture of CRC, this review discusses genetic factors that modify environmental predictors of CRC, as well as examples of how genetic insight has improved clinical surveillance, prevention and treatment strategies. In summary, substantial progress has been made in uncovering the genetic architecture of CRC, and continued research efforts are expected to identify additional genetic risk factors that further our biological understanding of this disease. Subsequently these new insights will lead to improved treatment and prevention of colorectal cancer. PMID:26187503

  10. Genetic pediatric retinal diseases

    PubMed Central

    Say, Emil Anthony T.

    2014-01-01

    Hereditary pediatric retinal diseases are a diverse group of disorders with pathologies affecting different cellular structures or retinal development. Many can mimic typical pediatric retinal disease such as retinopathy of prematurity, vitreous hemorrhage, retinal detachment and cystoid macular edema. Multisystem involvement is frequently seen in hereditary pediatric retinal disease. A thorough history coupled with a good physical examination can oftentimes lead the ophthalmologist or pediatrician to the correct genetic test and correct diagnosis. In some instances, evaluation of parents or siblings may be required to determine familial involvement when the history is inconclusive or insufficient and clinical suspicion is high.

  11. [Genetic ocular diseases].

    PubMed

    Hamel, Christian P

    2015-04-01

    Genetic ocular diseases are inherited Mendelian conditions (prevalence 1/1000) in which any tissue of the eye could be involved (cornea, lens, iridocomeal angle, vitrous, retina, choroid, sclera). More than 200 genes are responsible for inherited retinal dystrophies and even more genes remain to be identified. These genes belong to many metabolisms essential to the photoreceptor function. Gene therapy and retinal prosthesis are the two most promising therapeutic strategies currently in clinical trials which are expected to provide visual improvement in short term.

  12. Genetics, Paleontology, and Macroevolution

    NASA Astrophysics Data System (ADS)

    Levinton, Jeffrey S.

    2001-08-01

    This expanded and updated second edition offers a comprehensive look at macroevolution and its underpinnings, with a primary emphasis on animal evolution. From a Neodarwinian point of view, the book integrates evolutionary processes at all levels to explain the diversity of animal life. It examines a wide range of topics including genetics, speciation, development, evolution, constructional and functional aspects of form, fossil lineages, and systematics, and --in a major new chapter--takes a hard look at the Cambrian explosion. The author delves into the age of molecular science and integrates important recent contributions made to our understanding of evolution.

  13. Genetic pediatric retinal diseases.

    PubMed

    Say, Emil Anthony T

    2014-12-01

    Hereditary pediatric retinal diseases are a diverse group of disorders with pathologies affecting different cellular structures or retinal development. Many can mimic typical pediatric retinal disease such as retinopathy of prematurity, vitreous hemorrhage, retinal detachment and cystoid macular edema. Multisystem involvement is frequently seen in hereditary pediatric retinal disease. A thorough history coupled with a good physical examination can oftentimes lead the ophthalmologist or pediatrician to the correct genetic test and correct diagnosis. In some instances, evaluation of parents or siblings may be required to determine familial involvement when the history is inconclusive or insufficient and clinical suspicion is high. PMID:27625880

  14. Genetic and environmental contributions.

    PubMed

    Jensen, M D

    2000-03-01

    There is a remarkable variability in insulin action in humans. Depending upon the definition of the insulin resistance syndrome, different inheritability/environmental influences on insulin action are reported. The environmental contributions to insulin resistance appear to account for approximately 50% of this syndrome. Obese and sedentary insulin-resistant individuals can see dramatic improvement in insulin sensitivity with weight reduction and fitness training. The degree to which obesity is determined by genetic influences will have a substantial impact on insulin resistance in the Western populations. Familial components also appear to account for approximately 50% of the variation and insulin action (as commonly defined by glucose metabolic effects).

  15. Genetically Altered Plant Species

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Researchers in Robert Ferl's lab at the University of Florida in Gainesville, genetically altered this Arabdopsis Thaliana (a brassica species) plant to learn how extreme environments, such as the low atmospheric pressure on Mars, affect plant genes. They inserted green fluorescent protein (GFP) near the on/off switches for anoxia and drought genes. When those genes were turned on after exposure to reduced atmospheric pressure, GFP was turned on as well, causing cells expressing those genes to glow green under a blue light. The natural fluorescence of chlorophyll accounts for the red glow.

  16. The media and behavioral genetics: Alternatives coexisting with addiction genetics

    PubMed Central

    Dingel, Molly J.; Ostergren, Jenny; McCormick, Jennifer B.; Hammer, Rachel; Koenig, Barbara A.

    2015-01-01

    To understand public discourse in the U.S. on genetic causation of behavioral disorders, we analyzed media representations of genetic research on addiction published between 1990 and 2010. We conclude first that the media simplistically represent biological bases of addiction and willpower as being mutually exclusive: behaviors are either genetically determined, or they are a choice. Second, most articles provide only cursory or no treatment of the environmental contribution. A media focus on genetics directs attention away from environmental factors. Rhetorically, media neglect the complexity underlying of the etiology of addiction and direct focus back toward individual causation and responsibility. PMID:26392644

  17. Genetics of Melanocytic Nevi

    PubMed Central

    Roh, Mi Ryung; Eliades, Philip; Gupta, Sameer; Tsao, Hensin

    2015-01-01

    Melanocytic nevi are a benign clonal proliferation of cells expressing the melanocytic phenotype, with heterogeneous clinical and molecular characteristics. In this review, we discuss the genetics of nevi by salient nevi subtypes: congenital melanocytic nevi, acquired melanocytic nevi, blue nevi, and Spitz nevi. While the molecular etiology of nevi has been less thoroughly studied than melanoma, it is clear that nevi and melanoma share common driver mutations. Acquired melanocytic nevi harbor oncogenic mutations in BRAF, which is the predominant oncogene associated with melanoma. Congenital melanocytic nevi and blue nevi frequently harbor NRAS mutations and GNAQ mutations, respectively, while Spitz and atypical Spitz tumors often exhibit HRAS and kinase rearrangements. These initial “driver” mutations are thought to trigger the establishment of benign nevi. After this initial phase of cell proliferation, a senescence program is executed, causing termination of nevi growth. Only upon the emergence of additional tumorigenic alterations, which may provide an escape from oncogene-induced senescence, can malignant progression occur. Here, we review the current literature on the pathobiology and genetics of nevi in the hope that additional studies of nevi promise to inform our understanding of the transition from benign neoplasm to malignancy. PMID:26300491

  18. Genetic circuit design automation.

    PubMed

    Nielsen, Alec A K; Der, Bryan S; Shin, Jonghyeon; Vaidyanathan, Prashant; Paralanov, Vanya; Strychalski, Elizabeth A; Ross, David; Densmore, Douglas; Voigt, Christopher A

    2016-04-01

    Computation can be performed in living cells by DNA-encoded circuits that process sensory information and control biological functions. Their construction is time-intensive, requiring manual part assembly and balancing of regulator expression. We describe a design environment, Cello, in which a user writes Verilog code that is automatically transformed into a DNA sequence. Algorithms build a circuit diagram, assign and connect gates, and simulate performance. Reliable circuit design requires the insulation of gates from genetic context, so that they function identically when used in different circuits. We used Cello to design 60 circuits forEscherichia coli(880,000 base pairs of DNA), for which each DNA sequence was built as predicted by the software with no additional tuning. Of these, 45 circuits performed correctly in every output state (up to 10 regulators and 55 parts), and across all circuits 92% of the output states functioned as predicted. Design automation simplifies the incorporation of genetic circuits into biotechnology projects that require decision-making, control, sensing, or spatial organization.

  19. Genetically engineered plasmonic nanoarrays.

    PubMed

    Forestiere, Carlo; Pasquale, Alyssa J; Capretti, Antonio; Miano, Giovanni; Tamburrino, Antonello; Lee, Sylvanus Y; Reinhard, Björn M; Dal Negro, Luca

    2012-04-11

    In the present Letter, we demonstrate how the design of metallic nanoparticle arrays with large electric field enhancement can be performed using the basic paradigm of engineering, namely the optimization of a well-defined objective function. Such optimization is carried out by coupling a genetic algorithm with the analytical multiparticle Mie theory. General design criteria for best enhancement of electric fields are obtained, unveiling the fundamental interplay between the near-field plasmonic and radiative photonic coupling. Our optimization approach is experimentally validated by surface-enhanced Raman scattering measurements, which demonstrate how genetically optimized arrays, fabricated using electron beam lithography, lead to order of ten improvement of Raman enhancement over nanoparticle dimer antennas, and order of one hundred improvement over optimal nanoparticle gratings. A rigorous design of nanoparticle arrays with optimal field enhancement is essential to the engineering of numerous nanoscale optical devices such as plasmon-enhanced biosensors, photodetectors, light sources and more efficient nonlinear optical elements for on chip integration. PMID:22381056

  20. Genetics of Hypogonadotropic Hypogonadism.

    PubMed

    Topaloglu, A Kemal; Kotan, L Damla

    2016-01-01

    Hypogonadotropic hypogonadism (HH) often manifests as pubertal delay. A considerable proportion of cases of HH is due to genetic mutations. Recognizing those mutated genes and associated phenotypes may improve our diagnostic capabilities. GNRHR and TACR3 should be the first two genes to be screened in a clinical setting for equivocal cases such as constitutional delay in puberty versus idiopathic HH. In Kallmann syndrome (KS), according to the presence of certain accompanying clinical features, genetic screening for particular gene(s) may be prioritized: synkinesia (KAL1), dental agenesis (FGF8/FGFR1), bony anomalies (FGF8/FGFR1), and hearing loss (CHD7, SOX10). FEZF1 has recently been added to the growing list of KS genes. Also, discovery of mutations in KISS1/KISS1R and TAC3/TACR3 in kisspeptin and neurokinin B signaling, respectively, has provided major advancements in our understanding of the biology of the gonadotropin-releasing hormone pulse generator. Identification of further causative mutations accounting for the HH phenotype, which is now more feasible with the increasing popularity of whole exome sequencing, may provide deeper insight into the biology of the hypothalamic-pituitary-gonadal axis.

  1. Molecular genetics of ABO.

    PubMed

    Yamamoto, F

    2000-01-01

    This year commemorates the 100th anniversary of the discovery of the ABO blood group system by Karl Landsteiner. His findings of red cell agglutination by serum and recognition of blood groups laid the scientific basis for safe practice of blood transfusion. Even though dozens of blood systems have been identified, the ABO system still remains to be one of the most important systems in transfusion medicine. In 1990, we elucidated the molecular genetic basis of three major alleles at the ABO locus. Since then we have witnessed the progress in our understanding of ABO genes and A and B glycosyltransferases specified by a variety of functional alleles at this locus. Mutations affecting the activity and specificity of the enzymes have been identified. Not only has ABO genotyping become possible, but it has also become possible to genetically engineer the activity and specificity of the enzymes. We are now at a point of embarking upon the quest of understanding the functional significance of ABO polymorphism.

  2. The Genetics of Dystonias

    PubMed Central

    LeDoux, Mark S.

    2016-01-01

    Dystonia has been defined as a syndrome of involuntary, sustained muscle contractions affecting one or more sites of the body, frequently causing twisting and repetitive movements or abnormal postures. Dystonia is also a clinical sign that can be the presenting or prominent manifestation of many neurodegenerative and neuro-metabolic disorders. Etiological categories include primary dystonia, secondary dystonia, heredodegenerative diseases with dystonia, and dystonia plus. Primary dystonia includes syndromes in which dystonia is the sole phenotypic manifestation with the exception that tremor can be present as well. Most primary dystonia begins in adults, and approximately 10% of probands report one or more affected family members. Many cases of childhood- and adolescent-onset dystonia are due to mutations in TOR1A and THAP1. Mutations in THAP1 and CIZ1 have been associated with sporadic and familial adult-onset dystonia. Although significant recent progress had been made in defining the genetic basis for most of the dystonia-plus and heredodegenerative diseases with dystonia, a major gap remains in understanding the genetic etiologies for most cases of adult-onset primary dystonia. Common themes in the cellular biology of dystonia include G1/S cell cycle control, monoaminergic neurotransmission, mitochondrial dysfunction, and the neuronal stress response. PMID:22989765

  3. Biology, Genetics, and Environment

    PubMed Central

    Wall, Tamara L.; Luczak, Susan E.; Hiller-Sturmhöfel, Susanne

    2016-01-01

    Gene variants encoding several of the alcohol-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), are among the largest genetic associations with risk for alcohol dependence. Certain genetic variants (i.e., alleles)—particularly the ADH1B*2, ADH1B*3, ADH1C*1, and ALDH2*2 alleles—have been associated with lower rates of alcohol dependence. These alleles may lead to an accumulation of acetaldehyde during alcohol metabolism, which can result in heightened subjective and objective effects. The prevalence of these alleles differs among ethnic groups; ADH1B*2 is found frequently in northeast Asians and occasionally Caucasians, ADH1B*3 is found predominantly in people of African ancestry, ADH1C*1 varies substantially across populations, and ALDH2*2 is found almost exclusively in northeast Asians. Differences in the prevalence of these alleles may account at least in part for ethnic differences in alcohol consumption and alcohol use disorder (AUD). However, these alleles do not act in isolation to influence the risk of AUD. For example, the gene effects of ALDH2*2 and ADH1B*2 seem to interact. Moreover, other factors have been found to influence the extent to which these alleles affect a person’s alcohol involvement, including developmental stage, individual characteristics (e.g., ethnicity, antisocial behavior, and behavioral undercontrol), and environmental factors (e.g., culture, religion, family environment, and childhood adversity). PMID:27163368

  4. Genetic circuit design automation.

    PubMed

    Nielsen, Alec A K; Der, Bryan S; Shin, Jonghyeon; Vaidyanathan, Prashant; Paralanov, Vanya; Strychalski, Elizabeth A; Ross, David; Densmore, Douglas; Voigt, Christopher A

    2016-04-01

    Computation can be performed in living cells by DNA-encoded circuits that process sensory information and control biological functions. Their construction is time-intensive, requiring manual part assembly and balancing of regulator expression. We describe a design environment, Cello, in which a user writes Verilog code that is automatically transformed into a DNA sequence. Algorithms build a circuit diagram, assign and connect gates, and simulate performance. Reliable circuit design requires the insulation of gates from genetic context, so that they function identically when used in different circuits. We used Cello to design 60 circuits forEscherichia coli(880,000 base pairs of DNA), for which each DNA sequence was built as predicted by the software with no additional tuning. Of these, 45 circuits performed correctly in every output state (up to 10 regulators and 55 parts), and across all circuits 92% of the output states functioned as predicted. Design automation simplifies the incorporation of genetic circuits into biotechnology projects that require decision-making, control, sensing, or spatial organization. PMID:27034378

  5. Genetic code for sine

    NASA Astrophysics Data System (ADS)

    Abdullah, Alyasa Gan; Wah, Yap Bee

    2015-02-01

    The computation of the approximate values of the trigonometric sines was discovered by Bhaskara I (c. 600-c.680), a seventh century Indian mathematician and is known as the Bjaskara's I's sine approximation formula. The formula is given in his treatise titled Mahabhaskariya. In the 14th century, Madhava of Sangamagrama, a Kerala mathematician astronomer constructed the table of trigonometric sines of various angles. Madhava's table gives the measure of angles in arcminutes, arcseconds and sixtieths of an arcsecond. The search for more accurate formulas led to the discovery of the power series expansion by Madhava of Sangamagrama (c.1350-c. 1425), the founder of the Kerala school of astronomy and mathematics. In 1715, the Taylor series was introduced by Brook Taylor an English mathematician. If the Taylor series is centered at zero, it is called a Maclaurin series, named after the Scottish mathematician Colin Maclaurin. Some of the important Maclaurin series expansions include trigonometric functions. This paper introduces the genetic code of the sine of an angle without using power series expansion. The genetic code using square root approach reveals the pattern in the signs (plus, minus) and sequence of numbers in the sine of an angle. The square root approach complements the Pythagoras method, provides a better understanding of calculating an angle and will be useful for teaching the concepts of angles in trigonometry.

  6. Genetics and plant development.

    PubMed

    Prunet, Nathanaël; Meyerowitz, Elliot M

    2016-01-01

    There are only three grand theories in biology: the theory of the cell, the theory of the gene, and the theory of evolution. Two of these, the cell and gene theories, originated in the study of plants, with the third resulting in part from botanical considerations as well. Mendel's elucidation of the rules of inheritance was a result of his experiments on peas. The rediscovery of Mendel's work in 1900 was by the botanists de Vries, Correns, and Tschermak. It was only in subsequent years that animals were also shown to have segregation of genetic elements in the exact same manner as had been shown in plants. The story of developmental biology is different - while the development of plants has long been studied, the experimental and genetic approaches to developmental mechanism were developed via experiments on animals, and the importance of genes in development (e.g., Waddington, 1940) and their use for understanding developmental mechanisms came to botanical science much later - as late as the 1980s.

  7. [Genetics of congenital deafness].

    PubMed

    Faundes, Víctor; Pardo, Rosa Andrea; Castillo Taucher, Silvia

    2012-10-20

    Congenital deafness is defined as the hearing loss which is present at birth and, consequently, before speech development. It is the most prevalent sensor neural disorder in developed countries, and its incidence is estimated between 1-3 children per 1,000 newborns, of which more than 50% are attributable to genetics causes. Deafness can be classified as syndromic or non-syndromic. In the first case, it is associated with outer ear malformations and/or systemic findings. More than 400 syndromes accompanied of deafness have been described, which represent about 30% of cases of congenital hearing loss. The remaining percentage corresponds to non-syndromic cases: 75-85% are autosomal recessive, 15-24% are autosomal dominant, and 1-2% are X-linked. The evaluation of a child with deafness requires a multidisciplinary collaboration among specialists, who must coordinate themselves and give information to the affected family. The aims of establishing a diagnosis are to predict other manifestations that may suggest some syndrome and to anticipate their management, as well as to perform genetic counseling to parents and affected individuals.

  8. HDL genetic defects.

    PubMed

    Nair, Devaki R; Nair, Arun; Jain, Anjly

    2014-01-01

    High density lipoprotein cholesterol (HDL-C) and its related apolipoproteins form part of the reverse cholesterol transport system that removes excessive cholesterol from the periphery to the liver. Many transport proteins and enzymes that are involved in this process are susceptible to genetic defects that influence plasma HDL-C concentrations and HDL function. The HDL-C concentration in the blood may not be as important as the function of this lipid fraction. The genetic defects affecting plasma HDL-C concentrations do not always show a consistent relationship with atherosclerosis. Familial hypoalphalipoproteinaemia is associated with mutations in genes responsible for the transport proteins or the enzymes involved in the biogenesis of HDL-C. Inheritance of a Milano mutation of apolipoprotein A1 decreases the risk of atherosclerotic disease despite low circulating levels of HDL-C. Tangier disease and Fish Eye disease are caused by mutations in the ATP binding cassette A1 (ABCA1), a transport protein, and lecithin cholesterol acyl transferase (LCAT), an enzyme, involved in the esterification of cholesterol, respectively. Patients with these conditions have very low levels of HDL-C concentration. The association between both these conditions and the risk of cardiovascular disease (CVD) is variable and inconsistent. Understanding the molecular mechanism of HDL biogenesis not only helped in defining the pathophysiology of low and high HDL-C syndromes, but also in developing new treatment options to raise HDL-C levels. PMID:24953397

  9. Applied equine genetics

    PubMed Central

    FINNO, C. J.; BANNASCH, D. L.

    2015-01-01

    Summary Genome sequencing of the domestic horse and subsequent advancements in the field of equine genomics have led to an explosion in the development of tools for mapping traits and diseases and evaluating gene expression. The objective of this review is to discuss the current progress in the field of equine genomics, with specific emphasis on assembly and analysis of the reference sequence and subsequent sequencing of a Quarter Horse mare; the genomic tools currently available to researchers and their implications in genomic investigations in the horse; the genomics of Mendelian and non-Mendelian traits; the genomics of performance traits and considerations regarding genetic testing in the horse. The whole-genome sequencing of a Quarter Horse mare has provided additional variants within the equine genome that extend past single nucleotide polymorphisms to include insertions/deletions and copy number variants. Equine single nucleotide polymorphism arrays have allowed for the investigation of both simple and complex genetic traits while DNA microarrays have provided a tool for examining gene expression across various tissues and with certain disease conditions. Recently, next-generation sequencing has become more affordable and both whole-genome DNA sequencing and transcriptome-wide RNA sequencing are methodologies that are being applied to equine genomic research. Research in the field of equine genomics continues to expand rapidly as the cost of genotyping and sequencing decreases, resulting in a need for quality bioinformatics software and expertise to appropriately handle both the size and complexity of these data. PMID:24802051

  10. Genetics of congenital hypothyroidism

    PubMed Central

    Park, S; Chatterjee, V

    2005-01-01

    Congenital hypothyroidism is the most common neonatal metabolic disorder and results in severe neurodevelopmental impairment and infertility if untreated. Congenital hypothyroidism is usually sporadic but up to 2% of thyroid dysgenesis is familial, and congenital hypothyroidism caused by organification defects is often recessively inherited. The candidate genes associated with this genetically heterogeneous disorder form two main groups: those causing thyroid gland dysgenesis and those causing dyshormonogenesis. Genes associated with thyroid gland dysgenesis include the TSH receptor in non-syndromic congenital hypothyroidism, and Gsα and the thyroid transcription factors (TTF-1, TTF-2, and Pax-8), associated with different complex syndromes that include congenital hypothyroidism. Among those causing dyshormonogenesis, the thyroid peroxidase and thyroglobulin genes were initially described, and more recently PDS (Pendred syndrome), NIS (sodium iodide symporter), and THOX2 (thyroid oxidase 2) gene defects. There is also early evidence for a third group of congenital hypothyroid conditions associated with iodothyronine transporter defects associated with severe neurological sequelae. This review focuses on the genetic aspects of primary congenital hypothyroidism. PMID:15863666

  11. Clinical Genetics of Alzheimer's Disease

    PubMed Central

    Zou, Zhangyu; Liu, Changyun; Che, Chunhui; Huang, Huapin

    2014-01-01

    Alzheimer's disease (AD) is the most common progressive neurodegenerative disease and the most common form of dementia in the elderly. It is a complex disorder with environmental and genetic components. There are two major types of AD, early onset and the more common late onset. The genetics of early-onset AD are largely understood with mutations in three different genes leading to the disease. In contrast, while susceptibility loci and alleles associated with late-onset AD have been identified using genetic association studies, the genetics of late-onset Alzheimer's disease are not fully understood. Here we review the known genetics of early- and late-onset AD, the clinical features of EOAD according to genotypes, and the clinical implications of the genetics of AD. PMID:24955352

  12. Genetic specificity of face recognition.

    PubMed

    Shakeshaft, Nicholas G; Plomin, Robert

    2015-10-13

    Specific cognitive abilities in diverse domains are typically found to be highly heritable and substantially correlated with general cognitive ability (g), both phenotypically and genetically. Recent twin studies have found the ability to memorize and recognize faces to be an exception, being similarly heritable but phenotypically substantially uncorrelated both with g and with general object recognition. However, the genetic relationships between face recognition and other abilities (the extent to which they share a common genetic etiology) cannot be determined from phenotypic associations. In this, to our knowledge, first study of the genetic associations between face recognition and other domains, 2,000 18- and 19-year-old United Kingdom twins completed tests assessing their face recognition, object recognition, and general cognitive abilities. Results confirmed the substantial heritability of face recognition (61%), and multivariate genetic analyses found that most of this genetic influence is unique and not shared with other cognitive abilities.

  13. Population genetic structure and ecotoxicology.

    PubMed Central

    Guttman, S I

    1994-01-01

    Electrophoretic analyses of population genetic structure, both in the laboratory and in the field, have documented significant shifts in allozyme genotype frequencies in a variety of aquatic taxa as a result of environmental impacts. Studies are documented which indicate that contaminants may select for individuals with tolerant allozyme genotypes, causing the potential loss of individuals with sensitive genotypes. This may diminish the genetic variability and fitness of affected populations and make them more susceptible to extinction following a subsequent stress. Future research involving population genetic structure and ecotoxicology should focus on determining the mechanism of sensitivity, documenting multigenerational effects of chronic laboratory exposure on population genetic composition, investigating whether previously stressed and genetically impacted populations are more susceptible to further natural and/or anthropogenic stressors, and establishing the utility of population genetic structure as a sensitive monitor of impacts in aquatic systems and their subsequent remediation. PMID:7713044

  14. Genetic influences on brain structure.

    PubMed

    Thompson, P M; Cannon, T D; Narr, K L; van Erp, T; Poutanen, V P; Huttunen, M; Lönnqvist, J; Standertskjöld-Nordenstam, C G; Kaprio, J; Khaledy, M; Dail, R; Zoumalan, C I; Toga, A W

    2001-12-01

    Here we report on detailed three-dimensional maps revealing how brain structure is influenced by individual genetic differences. A genetic continuum was detected in which brain structure was increasingly similar in subjects with increasing genetic affinity. Genetic factors significantly influenced cortical structure in Broca's and Wernicke's language areas, as well as frontal brain regions (r2(MZ) > 0.8, p < 0.05). Preliminary correlations were performed suggesting that frontal gray matter differences may be linked to Spearman's g, which measures successful test performance across multiple cognitive domains (p < 0.05). These genetic brain maps reveal how genes determine individual differences, and may shed light on the heritability of cognitive and linguistic skills, as well as genetic liability for diseases that affect the human cortex. PMID:11694885

  15. Genetic Dissection of Neural Circuits

    PubMed Central

    Luo, Liqun; Callaway, Edward M.; Svoboda, Karel

    2009-01-01

    Understanding the principles of information processing in neural circuits requires systematic characterization of the participating cell types and their connections, and the ability to measure and perturb their activity. Genetic approaches promise to bring experimental access to complex neural systems, including genetic stalwarts such as the fly and mouse, but also to nongenetic systems such as primates. Together with anatomical and physiological methods, cell-type-specific expression of protein markers and sensors and transducers will be critical to construct circuit diagrams and to measure the activity of genetically defined neurons. Inactivation and activation of genetically defined cell types will establish causal relationships between activity in specific groups of neurons, circuit function, and animal behavior. Genetic analysis thus promises to reveal the logic of the neural circuits in complex brains that guide behaviors. Here we review progress in the genetic analysis of neural circuits and discuss directions for future research and development. PMID:18341986

  16. Genetic diagnosis of human embryos.

    PubMed

    Bonnicksen, Andrea

    1992-01-01

    For all the worried talk about genetic engineering over the last two decades, it is surprising how quietly plans for the genetic diagnosis of human embryos have developed. The issues raised warrant careful examination: what needs are met through embryo diagnosis? Who bears responsibility for monitoring this technique? Under what overarching ethic should embryo diagnosis and, eventually, embryo therapy, be applied? What are the broader social implications raised by the genetic diagnosis of human embryos?

  17. Genetic studies of substance abuse.

    PubMed

    Vanyukov, M M; Tarter, R E

    2000-05-01

    Genetic studies of substance abuse indicate that variation in the risk for the disorder in the population is contributed by differences in both individual genotypes and environment. Recent developments in genetics raise the possibility of disentangling the complex system of genotype-environment interaction that determines the development of the individual behavioral phenotype. This paper reviews the concepts, methods and results pertaining to genetic investigation of substance abuse.

  18. Ethical issues in perinatal genetics.

    PubMed

    Chervenak, Frank A; McCullough, Laurence B

    2011-04-01

    Ethics is an essential dimension of perinatal genetics. This article introduces perinatologists to the ethical principles of beneficence and respect for autonomy and uses these ethical principles to articulate the ethical concept of the fetus as a patient. Together these constitute an ethical framework that we apply to risk assessment, in response to which women may be divided into four groups: prenatal genetic counseling, and the responsible management of pregnancies complicated by genetic anomalies of the fetus.

  19. Clinical Genetic Testing in Epilepsy

    PubMed Central

    2015-01-01

    New technologies for mutation detection in the human genome have greatly increased our understanding of epilepsy genetics. Application of genomic technologies in the clinical setting allows for more efficient genetic diagnosis in some patients; therefore, it is important to understand the types of tests available and the types of mutations that can be detected. Making a genetic diagnosis improves overall patient care by enhancing prognosis and recurrence risk counseling and informing treatment decisions. PMID:26316867

  20. Ethical issues in perinatal genetics.

    PubMed

    Chervenak, Frank A; McCullough, Laurence B

    2011-04-01

    Ethics is an essential dimension of perinatal genetics. This article introduces perinatologists to the ethical principles of beneficence and respect for autonomy and uses these ethical principles to articulate the ethical concept of the fetus as a patient. Together these constitute an ethical framework that we apply to risk assessment, in response to which women may be divided into four groups: prenatal genetic counseling, and the responsible management of pregnancies complicated by genetic anomalies of the fetus. PMID:21051301

  1. Genetic screening: marvel or menace?

    PubMed

    Rowley, P T

    1984-07-13

    Genetic screening is a systematic search in the population for persons of certain genotypes. The usual purpose is to detect persons who themselves or whose offspring are at risk for genetic diseases or genetically determined susceptibilities to environmental agents. Is genetic screening a marvel about to free us from the scourge of genetic disease or a menace about to invade our privacy and determine who may reproduce? There are three different types of genetic screening. Newborn screening identifies serious genetic disease at birth, permitting prompt treatment to prevent mental and physical retardation. Fetal screening and prenatal diagnosis identify genetic disease in the fetus permitting selective termination of pregnancy and the opportunity to have children free of defects detectable in utero. Carrier screening identifies individuals heterozygous for a gene for a serious recessive disease who may be at risk for affected offspring. The challenge to society is to provide (by way of cost-effective programs) expert services, including genetic counseling and follow-up, to all who may benefit, to ensure confidentiality and freedom of choice, and to avoid misunderstanding and stigmatization. It is recommended that the objective of screening programs should be to maximize the options available to families at risk rather than to reduce the incidence of genetic diseases. Whenever possible, the providers of these services should be the providers of primary health care. Urgently needed are a greater awareness of avoidable genetic diseases on the part of primary care providers and efforts to familiarize the public with the basic concepts of human genetics through the public school system.

  2. Genetic screening: marvel or menace?

    PubMed

    Rowley, P T

    1984-07-13

    Genetic screening is a systematic search in the population for persons of certain genotypes. The usual purpose is to detect persons who themselves or whose offspring are at risk for genetic diseases or genetically determined susceptibilities to environmental agents. Is genetic screening a marvel about to free us from the scourge of genetic disease or a menace about to invade our privacy and determine who may reproduce? There are three different types of genetic screening. Newborn screening identifies serious genetic disease at birth, permitting prompt treatment to prevent mental and physical retardation. Fetal screening and prenatal diagnosis identify genetic disease in the fetus permitting selective termination of pregnancy and the opportunity to have children free of defects detectable in utero. Carrier screening identifies individuals heterozygous for a gene for a serious recessive disease who may be at risk for affected offspring. The challenge to society is to provide (by way of cost-effective programs) expert services, including genetic counseling and follow-up, to all who may benefit, to ensure confidentiality and freedom of choice, and to avoid misunderstanding and stigmatization. It is recommended that the objective of screening programs should be to maximize the options available to families at risk rather than to reduce the incidence of genetic diseases. Whenever possible, the providers of these services should be the providers of primary health care. Urgently needed are a greater awareness of avoidable genetic diseases on the part of primary care providers and efforts to familiarize the public with the basic concepts of human genetics through the public school system. PMID:6729472

  3. Abundance of non-native crabs in intertidal habitats of New England with natural and artificial structure.

    PubMed

    Lovely, Christina M; O'Connor, Nancy J; Judge, Michael L

    2015-01-01

    Marine habitats containing complex physical structure (e.g., crevices) can provide shelter from predation for benthic invertebrates. To examine effects of natural and artificial structure on the abundance of intertidal juvenile crabs, 2 experiments were conducted in Kingston Bay, Massachusetts, USA, from July to September, 2012. In the first experiment, structure was manipulated in a two-factor design that was placed in the high intertidal for 3 one-week periods to test for both substrate type (sand vs. rock) and the presence or absence of artificial structure (mesh grow-out bags used in aquaculture, ∼0.5 m(2) with 62 mm(2) mesh openings). The Asian shore crab, Hemigrapsus sanguineus, and small individuals of the green crab, Carcinus maenas, were observed only in the treatments of rocks and mesh bag plus rocks. Most green crabs were small (<6 mm in carapace width) whereas H. sanguineus occurred in a wide range of sizes. In the second experiment, 3 levels of oyster-shell treatments were established using grow-out bags placed on a muddy sand substrate in the low intertidal zone: mesh grow-out bags without shells, grow-out bags with oyster shells, and grow-out bags containing live oysters. Replicate bags were deployed weekly for 7 weeks in a randomized complete block design. All crabs collected in the bags were juvenile C. maenas (1-15 mm carapace width), and numbers of crabs differed 6-fold among treatments, with most crabs present in bags with live oysters (29.5 ± 10.6 m(-2) [mean ± S.D.]) and fewest in bags without shells (4.9 ± 3.7 m(-2)). Both C. maenas and H. sanguineus occurred in habitats with natural structure (cobble rocks). The attraction of juvenile C. maenas to artificial structure consisting of plastic mesh bags containing both oyster shells and living oysters could potentially impact oyster aquaculture operations.

  4. Abundance of non-native crabs in intertidal habitats of New England with natural and artificial structure.

    PubMed

    Lovely, Christina M; O'Connor, Nancy J; Judge, Michael L

    2015-01-01

    Marine habitats containing complex physical structure (e.g., crevices) can provide shelter from predation for benthic invertebrates. To examine effects of natural and artificial structure on the abundance of intertidal juvenile crabs, 2 experiments were conducted in Kingston Bay, Massachusetts, USA, from July to September, 2012. In the first experiment, structure was manipulated in a two-factor design that was placed in the high intertidal for 3 one-week periods to test for both substrate type (sand vs. rock) and the presence or absence of artificial structure (mesh grow-out bags used in aquaculture, ∼0.5 m(2) with 62 mm(2) mesh openings). The Asian shore crab, Hemigrapsus sanguineus, and small individuals of the green crab, Carcinus maenas, were observed only in the treatments of rocks and mesh bag plus rocks. Most green crabs were small (<6 mm in carapace width) whereas H. sanguineus occurred in a wide range of sizes. In the second experiment, 3 levels of oyster-shell treatments were established using grow-out bags placed on a muddy sand substrate in the low intertidal zone: mesh grow-out bags without shells, grow-out bags with oyster shells, and grow-out bags containing live oysters. Replicate bags were deployed weekly for 7 weeks in a randomized complete block design. All crabs collected in the bags were juvenile C. maenas (1-15 mm carapace width), and numbers of crabs differed 6-fold among treatments, with most crabs present in bags with live oysters (29.5 ± 10.6 m(-2) [mean ± S.D.]) and fewest in bags without shells (4.9 ± 3.7 m(-2)). Both C. maenas and H. sanguineus occurred in habitats with natural structure (cobble rocks). The attraction of juvenile C. maenas to artificial structure consisting of plastic mesh bags containing both oyster shells and living oysters could potentially impact oyster aquaculture operations. PMID:26401456

  5. Abundance of non-native crabs in intertidal habitats of New England with natural and artificial structure

    PubMed Central

    Lovely, Christina M.; Judge, Michael L.

    2015-01-01

    Marine habitats containing complex physical structure (e.g., crevices) can provide shelter from predation for benthic invertebrates. To examine effects of natural and artificial structure on the abundance of intertidal juvenile crabs, 2 experiments were conducted in Kingston Bay, Massachusetts, USA, from July to September, 2012. In the first experiment, structure was manipulated in a two-factor design that was placed in the high intertidal for 3 one-week periods to test for both substrate type (sand vs. rock) and the presence or absence of artificial structure (mesh grow-out bags used in aquaculture, ∼0.5 m2 with 62 mm2 mesh openings). The Asian shore crab, Hemigrapsus sanguineus, and small individuals of the green crab, Carcinus maenas, were observed only in the treatments of rocks and mesh bag plus rocks. Most green crabs were small (<6 mm in carapace width) whereas H. sanguineus occurred in a wide range of sizes. In the second experiment, 3 levels of oyster-shell treatments were established using grow-out bags placed on a muddy sand substrate in the low intertidal zone: mesh grow-out bags without shells, grow-out bags with oyster shells, and grow-out bags containing live oysters. Replicate bags were deployed weekly for 7 weeks in a randomized complete block design. All crabs collected in the bags were juvenile C. maenas (1–15 mm carapace width), and numbers of crabs differed 6-fold among treatments, with most crabs present in bags with live oysters (29.5 ± 10.6 m−2 [mean ± S.D.]) and fewest in bags without shells (4.9 ± 3.7 m−2). Both C. maenas and H. sanguineus occurred in habitats with natural structure (cobble rocks). The attraction of juvenile C. maenas to artificial structure consisting of plastic mesh bags containing both oyster shells and living oysters could potentially impact oyster aquaculture operations. PMID:26401456

  6. Genetic comorbidities in Parkinson's disease

    PubMed Central

    Nalls, Mike A.; Saad, Mohamad; Noyce, Alastair J.; Keller, Margaux F.; Schrag, Anette; Bestwick, Jonathan P.; Traynor, Bryan J.; Gibbs, J. Raphael; Hernandez, Dena G.; Cookson, Mark R.; Morris, Huw R.; Williams, Nigel; Gasser, Thomas; Heutink, Peter; Wood, Nick; Hardy, John; Martinez, Maria; Singleton, Andrew B.

    2014-01-01

    Parkinson's disease (PD) has a number of known genetic risk factors. Clinical and epidemiological studies have suggested the existence of intermediate factors that may be associated with additional risk of PD. We construct genetic risk profiles for additional epidemiological and clinical factors using known genome-wide association studies (GWAS) loci related to these specific phenotypes to estimate genetic comorbidity in a systematic review. We identify genetic risk profiles based on GWAS variants associated with schizophrenia and Crohn's disease as significantly associated with risk of PD. Conditional analyses adjusting for SNPs near loci associated with PD and schizophrenia or PD and Crohn's disease suggest that spatially overlapping loci associated with schizophrenia and PD account for most of the shared comorbidity, while variation outside of known proximal loci shared by PD and Crohn's disease accounts for their shared genetic comorbidity. We examine brain methylation and expression signatures proximal to schizophrenia and Crohn's disease loci to infer functional changes in the brain associated with the variants contributing to genetic comorbidity. We compare our results with a systematic review of epidemiological literature, while the findings are dissimilar to a degree; marginal genetic associations corroborate the directionality of associations across genetic and epidemiological data. We show a strong genetically defined level of comorbidity between PD and Crohn's disease as well as between PD and schizophrenia, with likely functional consequences of associated variants occurring in brain. PMID:24057672

  7. Concepts of genetics: II edition

    SciTech Connect

    Klug, W.S.; Cummings, M.R.

    1986-01-01

    This book provides an introduction to the molecule, and progresses logically through cellular genetics and the genetics of organisms to the larger picture of population genetics. The Second Edition features new chapters on quantitative inheritance and recombinant DNA, a new appendix with a human gene map and coverage of gene disorders, expanded coverage of bacterial and viral genetics, and consolidated coverage of sex linkage, sex determination, sex chromosome abberations, and sex differentiation. Dozens of new figures are added in this edition. All diagrams, photographs, and tables work hand-in-hand with the text to explain important concepts. Practical exercises with answers at the back of the text provide immediate feedback.

  8. The Synthesis Paradigm in Genetics

    PubMed Central

    Rice, William R.

    2014-01-01

    Experimental genetics with model organisms and mathematically explicit genetic theory are generally considered to be the major paradigms by which progress in genetics is achieved. Here I argue that this view is incomplete and that pivotal advances in genetics—and other fields of biology—are also made by synthesizing disparate threads of extant information rather than generating new information from experiments or formal theory. Because of the explosive expansion of information in numerous “-omics” data banks, and the fragmentation of genetics into numerous subdisciplines, the importance of the synthesis paradigm will likely expand with time. PMID:24496401

  9. Legal aspects of genetic information.

    PubMed Central

    Andrews, L. B.

    1991-01-01

    The federally funded Human Genome Initiative will lead to the development of new capabilities to learn about an individual's genetic status. Legal issues are raised concerning patients' and other parties' access to that information. This article discusses the effect of existing statutes and case law on three pivotal questions: To what sort of information are people entitled? What control should people have over their genetic information? Do people have a right to refuse genetic information? The article emphasizes that the law protects a patient's right to obtain or refuse genetic information about oneself, as well as the right to control the dissemination of that information to others. PMID:1897258

  10. The genetics of dilated cardiomyopathy

    PubMed Central

    Dellefave, Lisa; McNally, Elizabeth M.

    2010-01-01

    Purpose of review More than forty different individual genes have been implicated in the inheritance of dilated cardiomyopathy. For a subset of these genes, mutations can lead to a spectrum of cardiomyopathy that extends to hypertrophic cardiomyopathy and left ventricular noncompaction. In nearly all cases, there is an increased risk of arrhythmias. With some genetic mutations, extracardiac manifestations are likely to be present. The precise genetic etiology can usually not be discerned from the cardiac and/or extracardiac manifestations and requires molecular genetic diagnosis for prognostic determination and cardiac care. Recent findings Newer technologies are influencing genetic testing, especially cardiomyopathy genetic testing, where an increased number of genes are now routinely being tested simultaneously. While this approach to testing multiple genes is increasing the diagnostic yield, the analysis of multiple genes in one test is also resulting in a large amount of genetic information of unclear significance. Summary Genetic testing is highly useful in the care of patients and families, since it guides diagnosis, influences care and aids in prognosis. However, the large amount of benign human genetic variation may complicate genetic results, and often requires a skilled team to accurately interpret the findings. PMID:20186049

  11. Legal aspects of genetic information.

    PubMed

    Andrews, L B

    1991-01-01

    The federally funded Human Genome Initiative will lead to the development of new capabilities to learn about an individual's genetic status. Legal issues are raised concerning patients' and other parties' access to that information. This article discusses the effect of existing statutes and case law on three pivotal questions: To what sort of information are people entitled? What control should people have over their genetic information? Do people have a right to refuse genetic information? The article emphasizes that the law protects a patient's right to obtain or refuse genetic information about oneself, as well as the right to control the dissemination of that information to others.

  12. Genetics Home Reference: Kallmann syndrome

    MedlinePlus

    ... Encyclopedia: Hypogonadotropic Hypogonadism Encyclopedia: Smell - Impaired Health Topic: Endocrine Diseases Health Topic: Taste and Smell Disorders Genetic and Rare Diseases Information Center (7 links) ...

  13. Genetics of diabetic nephropathy.

    PubMed

    Parving, H H; Tarnow, L; Rossing, P

    1996-12-01

    Diabetic nephropathy is a clinical syndrome characterized by persistent albuminuria, a relentless decline in GFR, raised arterial blood pressure, and increased relative mortality for cardiovascular diseases. Diabetic nephropathy is a leading cause of end-stage renal failure. The pathogenesis of diabetic nephropathy is multifactorial, with contributions from metabolic abnormalities, hemodynamic alterations, and various growth factors and genetic factors. Epidemiologic and family studies have demonstrated that only a subset of the patients develop this complication that family clustering of nephropathy is present, and that ethnicity plays an important role in the risk of developing this kidney disease. Short stature and low birth weight are both associated with increased risk of developing diabetic nephropathy, supporting the hypothesis that genetic predisposition or factors operating in utero, in early childhood, or both contribute to the development of diabetic nephropathy. Studies elucidating phenotypic markers such as parenteral hypertension and systemic blood pressure elevation have yielded conflicting results. The contribution from elevated blood pressure only plays a minor role in the majority of the patients developing diabetic nephropathy. The majority of the studies have demonstrated increased sodium/lithium countertransport activity in insulin-dependent diabetes mellitus patients with nephropathy, whereas studies of this phenotypic marker in parents of patients with and without nephropathy have yielded conflicting results. Recently, studies of genetic markers involved in the regulation of blood pressure and levels of cardiovascular risk factors have been conducted. Several studies have demonstrated that the deletion polymorphism in the angiotensin-I-converting enzyme acts as a risk factor for cardiovascular disease in diabetic patients. However, a meta-analysis does not support the suggestion that this factor plays any role for the initiation of diabetic

  14. On Gene Concepts and Teaching Genetics: Episodes from Classical Genetics

    ERIC Educational Resources Information Center

    Burian, Richard M.

    2013-01-01

    This paper addresses the teaching of advanced high school courses or undergraduate courses for non-biology majors about genetics or history of genetics. It will probably be difficult to take the approach described here in a high school science course, although the general approach could help improve such courses. It would be ideal for a college…

  15. Genetic predisposition, non-genetic risk factors and coronary infarct

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Using a genetic predisposition score (GPS), additively integrating the associations of 11 polymorphisms with coronary heart disease (CHD), we examined the consequences of joint presence of high GPS and non-genetic CHD risk factors. Methods: Within the European Prospective Investigation i...

  16. [The Human Genome Project, genetic viability and genetic epidemiology].

    PubMed

    Hagymási, Krisztina; Tulassay, Zsolt

    2005-12-18

    The goal of the Human Genome Project to elucidate the complete sequence of the human genome has been achieved. The aims of the "post-genome" era are explaining the genetic information, characterisation of functional elements encoded in the human genome and mapping the human genetic variability as well. Two unrelated human beings also share 99.9% of their genomic sequence. The difference of 0.1% is the result of genetic polymorphisms: single nucleotide polymorphisms, repetitive sequences and insertion/deletion. The genetic differences, coupled with environmental exposures will determine the phenotypic variation we observe in health or disease. The disease-causing genetic variants can be identified by linkage analysis or association studies. The knowledge of human genome and application of multiple biomarkers will improve our ability to identify individuals at risk, so that preventive interventions can be applied, earlier diagnosis can be made and treatment can be optimized.

  17. Genetics in the art and art in genetics.

    PubMed

    Bukvic, Nenad; Elling, John W

    2015-01-15

    "Healing is best accomplished when art and science are conjoined, when body and spirit are probed together", says Bernard Lown, in his book "The Lost Art of Healing". Art has long been a witness to disease either through diseases which affected artists or diseases afflicting objects of their art. In particular, artists have often portrayed genetic disorders and malformations in their work. Sometimes genetic disorders have mystical significance; other times simply have intrinsic interest. Recognizing genetic disorders is also an art form. From the very beginning of my work as a Medical Geneticist I have composed personal "algorithms" to piece together evidence of genetics syndromes and diseases from the observable signs and symptoms. In this paper we apply some 'gestalt' Genetic Syndrome Diagnostic algorithms to virtual patients found in some art masterpieces. In some the diagnosis is clear and in others the artists' depiction only supports a speculative differential diagnosis.

  18. Genetics in the art and art in genetics.

    PubMed

    Bukvic, Nenad; Elling, John W

    2015-01-15

    "Healing is best accomplished when art and science are conjoined, when body and spirit are probed together", says Bernard Lown, in his book "The Lost Art of Healing". Art has long been a witness to disease either through diseases which affected artists or diseases afflicting objects of their art. In particular, artists have often portrayed genetic disorders and malformations in their work. Sometimes genetic disorders have mystical significance; other times simply have intrinsic interest. Recognizing genetic disorders is also an art form. From the very beginning of my work as a Medical Geneticist I have composed personal "algorithms" to piece together evidence of genetics syndromes and diseases from the observable signs and symptoms. In this paper we apply some 'gestalt' Genetic Syndrome Diagnostic algorithms to virtual patients found in some art masterpieces. In some the diagnosis is clear and in others the artists' depiction only supports a speculative differential diagnosis. PMID:25089030

  19. Network analyses structure genetic diversity in independent genetic worlds.

    PubMed

    Halary, Sébastien; Leigh, Jessica W; Cheaib, Bachar; Lopez, Philippe; Bapteste, Eric

    2010-01-01

    DNA flows between chromosomes and mobile elements, following rules that are poorly understood. This limited knowledge is partly explained by the limits of current approaches to study the structure and evolution of genetic diversity. Network analyses of 119,381 homologous DNA families, sampled from 111 cellular genomes and from 165,529 phage, plasmid, and environmental virome sequences, offer challenging insights. Our results support a disconnected yet highly structured network of genetic diversity, revealing the existence of multiple "genetic worlds." These divides define multiple isolated groups of DNA vehicles drawing on distinct gene pools. Mathematical studies of the centralities of these worlds' subnetworks demonstrate that plasmids, not viruses, were key vectors of genetic exchange between bacterial chromosomes, both recently and in the past. Furthermore, network methodology introduces new ways of quantifying current sampling of genetic diversity.

  20. Biomarkers, genetics and cancer

    SciTech Connect

    Anton-Guirgis, H.; Lynch, H.T.

    1985-01-01

    Biological markers can greatly facilitate identification of individuals at high cancer risk. This volume surveys the entire field of biological markers and how they promote early diagnosis of various hereditary cancer forms. Chapters written in down-to-earth style make the data relevant to practicing clinicians as well as research scientists. Markers for site-specific tumors are investigated from the standpoints of etiology and carcinogenesis. Particular attention is given to cancer genetic settings that could serve as models for further research. Methods of identifying both those at high cancer risk and those in a pre-cancerous state are clearly explained. Specific areas covered include polymorphic markers, multiple biological markers, hereditary adenomatosis, and carcino-embryonic antigens. Research findings from studies of twins, families, and first degree relatives offer valuable insights into heritable cancer syndromes.