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Sample records for carcinus maenas genetic

  1. Development and Application of Microsatellites in Carcinus maenas: Genetic Differentiation between Northern and Central Portuguese Populations

    PubMed Central

    Pascoal, Sónia; Creer, Simon; Taylor, Martin I.; Queiroga, Henrique; Carvalho, Gary; Mendo, Sónia

    2009-01-01

    Carcinus maenas, the common shore crab of European coastal waters, has recently gained notoriety due to its globally invasive nature associated with drastic ecological and economic effects. The native ubiquity and worldwide importance of C. maenas has resulted in it becoming one of the best-studied estuarine crustacean species globally. Accordingly, there is significant interest in investigating the population genetic structure of this broadly distributed crab along European and invaded coastlines. Here, we developed polymerase chain reaction (PCR) primers for one dinucleotide and two trinucleotide microsatellite loci, resulting from an enrichment process based on Portuguese populations. Combining these three new markers with six existing markers, we examined levels of genetic diversity and population structure of C. maenas in two coastal regions from Northern and Central Portugal. Genotypes showed that locus polymorphism ranged from 10 to 42 alleles (N = 135) and observed heterozygosity per locus ranged from 0.745 to 0.987 with expected heterozygosity ranging from 0.711 to 0.960; values typical of marine decapods. The markers revealed weak, but significant structuring among populations (global FST = 0.004) across a 450 km (over-water distance) spatial scale. Combinations of these and existing markers will be useful for studying population genetic parameters at a range of spatial scales of C. maenas throughout its expanding species range. PMID:19789651

  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. 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...

  5. Pattern and pathways for mercury lifespan bioaccumulation in Carcinus maenas.

    PubMed

    Coelho, J P; Reis, A T; Ventura, S; Pereira, M E; Duarte, A C; Pardal, M A

    2008-06-01

    Carcinus maenas is an important and exploited natural resource in temperate estuaries, being consumed by local populations and also used as fish bait. Through bioaccumulation and bioamplification processes occurring in polluted estuarine ecosystems, this species may directly or indirectly represent a major pathway for Human contamination. No information is available on the overall lifespan bioaccumulation pattern of mercury for this species, which would be an invaluable tool for assessing the risks associated with C. maenas harvest in contaminated areas. Taking that in mind, the main objectives of this work were to clarify the lifespan bioaccumulation pattern of mercury for this species. A consistent lifespan accumulation pattern was found for this species, both for total and organic mercury, and coherent differences were found between genders, suggesting different physiological responses to contamination. From our results two scenarios emerge: (a) for low mercury contamination areas where the diet is the major pathway for metal uptake, with higher levels in muscle and hepatopancreas (twice as high as in gills) and higher organic mercury fractions (as high as 80-90% in muscle), crabs bioaccumulate with age and (b) on high contaminated areas, environmental exposure is predominant, with higher levels found in gills (reaching 0.8 mg kg(-1)), lower organic fractions and no mercury increment with age. Detoxification strategies, dietary differences and species mobility may account for these two accumulation patterns.

  6. 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...

  7. 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...

  8. Green crab (Carcinus maenas) foraging efficiency reduced by fast flows.

    PubMed

    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.

  9. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. 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

  11. 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...

  12. 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...

  13. 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)

  14. 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 ...

  15. 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 ...

  16. 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

  17. 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).

  18. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. 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

  20. Parasites of the shore crab Carcinus maenas (L.): implications for reproductive potential and invasion success.

    PubMed

    Zetlmeisl, C; Hermann, J; Petney, T; Glenner, H; Griffiths, C; Taraschewski, H

    2011-03-01

    The European shore crab, Carcinus maenas, is one of the most successful marine invasive species. Its success has been in part attributed to the loss of parasites, rekindling an interest in host-parasite interactions and impacts on host fitness in this crab. In the present study, we investigated C. maenas populations from Europe, South Africa and Australia for parasites, and assessed their impact on the fitness of male crabs. For the shore crab, testes weight along with success in mating competition is traded off against other life-history traits. We therefore used this parameter as an indicator both for reproductive fitness and a possible resource trade-off in response to parasite infestation. In the native range, crabs infested with Sacculina carcini showed significantly lower testes weight than uninfected crabs. However, helminth parasites did not generally cause reduced testes weights. Crab populations from South Africa and Australia were either parasitized at very low prevalences, or were completely parasite free. However, no population level effect of this parasite release was reflected in testes weight. These findings do not support a severe fitness impact of helminth parasites on C. maenas, which questions the role of parasites on its population dynamics, both in the native area and for invasive success.

  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. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. 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.

  3. Biochemical and locomotor responses of Carcinus maenas exposed to the serotonin reuptake inhibitor fluoxetine.

    PubMed

    Mesquita, Sofia Raquel; Guilhermino, Lúcia; Guimarães, Laura

    2011-10-01

    The aim of this study was to assess the effects of the widely used anti-depressant fluoxetine on behaviour (locomotion), moulting, neuromuscular transmission, energy production and anti-oxidant defences' efficiency of the epibenthic crab Carcinus maenas. Crabs were individually exposed to fluoxetine concentrations for 7d. Effects on locomotion were assessed at the end of the exposure using an open field test adapted to C. maenas in the present study. Tissue samples were later collected to evaluate fluoxetine effects on physiological functions using the activity of key enzymes and other parameters as biomarkers, namely: N-acetyl-β-glucosaminidase (NAGase) in the epidermis (moulting) and the hepatopancreas; cholinesterases (ChE) in muscle (neuromuscular cholinergic transmission); NADP(+)-dependent isocitrate dehydrogenase (IDH) and lactate dehydrogenease (LDH) in muscle (energy production); glutathione S-transferases (GST) in hepatopancreas (biotransformation and oxidative stress system); glutathione reductase (GR), and glutathione peroxidade (GPx), total glutathione levels (TG) and lipid peroxidation levels in the hepatopancreas (anti-oxidant defences and oxidative damage). Because no information on C. maenas NAGase activity was previously available, its variation during the moult cycle was also investigated. The results showed that locomotion was significantly increased at fluoxetine concentrations equal or above 120 μg L⁻¹, with animals spending more time moving, walking longer distances than controls. Levels of NAGase activity were found to vary in relation to C. maenas moult cycle, but no alterations were observed after exposure to fluoxetine. Significant increases in the activity of ChE, GST and GR enzymes, and the levels of TG were found, with a lowest observed effect concentration (LOEC) of 120 μg L⁻¹. Effects on locomotion were significantly and positively correlated to those induced on ChE activity. The results raise concern when hypothesising

  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. De novo assembly of the Carcinus maenas transcriptome and characterization of innate immune system pathways.

    PubMed

    Verbruggen, Bas; Bickley, Lisa K; Santos, Eduarda M; Tyler, Charles R; Stentiford, Grant D; Bateman, Kelly S; van Aerle, Ronny

    2015-06-16

    The European shore crab, Carcinus maenas, is used widely in biomonitoring, ecotoxicology and for studies into host-pathogen interactions. It is also an important invasive species in numerous global locations. However, the genomic resources for this organism are still sparse, limiting research progress in these fields. To address this resource shortfall we produced a C. maenas transcriptome, enabled by the progress in next-generation sequencing technologies, and applied this to assemble information on the innate immune system in this species. We isolated and pooled RNA for twelve different tissues and organs from C. maenas individuals and sequenced the RNA using next generation sequencing on an Illumina HiSeq 2500 platform. After de novo assembly a transcriptome was generated encompassing 212,427 transcripts (153,699 loci). The transcripts were filtered, annotated and characterised using a variety of tools (including BLAST, MEGAN and RSEM) and databases (including NCBI, Gene Ontology and KEGG). There were differential patterns of expression for between 1,223 and 2,741 transcripts across tissues and organs with over-represented Gene Ontology terms relating to their specific function. Based on sequence homology to immune system components in other organisms, we show both the presence of transcripts for a series of known pathogen recognition receptors and response proteins that form part of the innate immune system, and transcripts representing the RNAi, Toll-like receptor signalling, IMD and JAK/STAT pathways. We have produced an assembled transcriptome for C. maenas that provides a significant molecular resource for wide ranging studies in this species. Analysis of the transcriptome has revealed the presence of a series of known targets and functional pathways that form part of their innate immune system and illustrate tissue specific differences in their expression patterns.

  6. 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

  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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Ontogeny of osmoregulatory structures and functions in the green crab Carcinus maenas (Crustacea, Decapoda).

    PubMed

    Cieluch, Ude; Anger, Klaus; Aujoulat, Fabien; Buchholz, Friedrich; Charmantier-Daures, Mireille; Charmantie, Guy

    2004-01-01

    The ontogeny of osmoregulation, the development of branchial transporting epithelia and the expression of the enzyme Na+/K+-ATPase were studied in Carcinus maenas (L.) obtained from the North Sea, Germany. Laboratory-reared zoea larvae, megalopae and young crabs were exposed to a wide range of salinities, and hemolymph osmolality was measured after 24 h exposure time (72 h in juveniles). Zoea I larvae slightly hyper-regulated in dilute media (10.2 per thousand and 17.0 per thousand ) and osmoconformed at >17 per thousand. All later zoeal stages (II-IV) osmoconformed in salinities from 10.2 per thousand to 44.3 per thousand. The megalopa hyper-regulated at salinities from 10.2 to 25.5 per thousand. Young crabs hyperregulated at salinities from 5.3 per thousand to 25.5 per thousand, showing an increase in their osmoregulatory capacity. The development of transporting epithelia and the expression of Na+/K+-ATPase were investigated by means of transmission electron microscopy and immunofluorescence microscopy. In the zoea IV, only a very light fluorescence staining was observed in gill buds. Epithelial cells were rather undifferentiated, without showing any features of ionocytes. Gills were present in the megalopa, where Na+/K+-ATPase was located in basal filaments of the posterior gills. In crab I juveniles and adults, Na+/K+-ATPase was noted in the three most posterior pairs of gills, but lacking in anterior gills. Ionocytes could first be recognized in filaments of megalopal posterior gills, persisting through subsequent stages at the same location. Thus, the development of the gills and the expression of Na+/K+-ATPase are closely correlated with the ontogeny of osmoregulatory abilities. The morphological two-step metamorphosis of C. maenas can also be regarded as an osmo-physiological metamorphosis, (i) from the osmoconforming zoeal stages to the weakly regulating megalopa, and (ii) to the effectively hyper-regulating juvenile and adult crabs.

  14. Effects of 4-nonylphenol on the endocrine system of the shore crab, Carcinus maenas.

    PubMed

    Lye, Christina M; Bentley, Matthew G; Galloway, Tamara

    2008-06-01

    There is a considerable body of evidence to suggest that many anthropogenic chemicals, most notably xeno-estrogens, are able to disrupt the endocrine system of vertebrates. There have been few comparable studies on the effects of exposure to these chemicals that may serve as biomarkers of endocrine disruption in aquatic invertebrate species. In addition, the evidence available is complex, conflicting, and far from conclusive. The present study aimed to investigate the impact of the xeno-estrogen 4-nonylphenol (4-NP, nominal concentrations 10-100 microg L(-1)) on the regulation and functioning of the endocrine system of the shore crab Carcinus maenas. It also set out to establish whether 4-NP are causing the effects (i.e., changes of exoskeletons including secondary sexual characteristics, pheromonally mediated behavior and ecdysone levels, and the presence of vt in the male hepatopancreas) found recently in wild shore crabs (Lye et al.,2005). The study utilizes morphological (e.g., gonadosomatic and hepatosomatic indices) and hormonal (ecdysteroid moulting hormone levels and the induction of female specific proteins, vitellins) biomarkers using radioimmunoassay and an indirect enzyme linked immunosorbent assay applied to the soluble protein fraction of adult male hepatopancreatic homogenates. Exposure of C. maenas to an effective concentration as low as 1.5 microg L(-1) 4-NP resulted in a reduced testis weight, increased liver weight, and altered levels of ecdysone equivalents compared to controls. Induction of vitellin-like proteins was absent in all samples tested. The ecological implications and the possible mechanisms for the action of 4-NP on the response of the shore crab to xeno-estrogen exposure are discussed.

  15. 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.

  16. 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.

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

    USGS Publications Warehouse

    Kuris, Armand M.; Torchin, Mark E.; Lafferty, Kevin 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. Sex-specific mediation of foraging in the shore crab, Carcinus maenas.

    PubMed

    Hayden, Dominic; Jennings, Alice; Müller, Carsten; Pascoe, David; Bublitz, Ralf; Webb, Heather; Breithaupt, Thomas; Watkins, Lloyd; Hardege, Jörg

    2007-08-01

    Experiments were conducted to investigate the sex-specific differences to feeding responses of the shore crab Carcinus maenas throughout the year. Results demonstrate that female shore crabs exhibit stronger feeding responses than males throughout the year with a significantly reduced feeding response in males during the summer months' reproductive season. We also studied the possible function(s) of the moulting hormone, 20-hydroxyecdysone (Crustecdysone) that has been described as a potential female-produced sex pheromone to initiate male reproductive behaviour in a number of crustaceans. We recently presented evidence that for shore crabs this is not the case and now show that the steroid is instead functioning as a sex-specific feeding deterrent protecting the moulting 'soft' female crabs. Whilst male shore crabs were deterred from prey (Mytilus edulis) and synthetic feeding stimulants glycine and taurine when these feeding stimulants were spiked with crustecdysone, intermoult female crabs were significantly less affected and rarely deterred from feeding. This sex specificity of the moulting hormone, in combination with the female sex pheromone, which has no anti-feeding properties, ensures that male crabs mate with soft-shelled, moulted females rather than engage in cannibalism, such as found frequently in cases when soft-shelled females are exposed to intermoult females.

  3. 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.

  4. 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

    2013-07-06

    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.

  5. 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

  6. Seed Predation by the Shore Crab Carcinus maenas: A Positive Feedback Preventing Eelgrass Recovery?

    PubMed Central

    2016-01-01

    There is an increasing interest to restore the ecosystem services that eelgrass provides, after their continuous worldwide decline. Most attempts to restore eelgrass using seeds are challenged by very high seed losses and the reasons for these losses are not all clear. We assess the impact of predation on seed loss and eelgrass establishment, and explore methods to decrease seed loss during restoration in the Swedish northwest coast. In a laboratory study we identified three previously undescribed seed predators, the shore crab Carcinus maenas, the hermit crab Pagurus bernhardus and the sea urchin Strongylocentrotus droebachiensis, of which shore crabs consumed 2–7 times more seeds than the other two species. The importance of shore crabs as seed predators was supported in field cage experiments where one enclosed crab caused 73% loss of seeds over a 1-week period on average (~ 21 seeds per day). Seedling establishment was significantly higher (14%) in cages that excluded predators over an 8-month period than in uncaged plots and cages that allowed predators but prevented seed-transport (0.5%), suggesting that seed predation constitutes a major source of seed loss in the study area. Burying the seeds 2 cm below the sediment surface prevented seed predation in the laboratory and decreased predation in the field, constituting a way to decrease seed loss during restoration. Shore crabs may act as a key feedback mechanism that prevent the return of eelgrass both by direct consumption of eelgrass seeds and as a predator of algal mesograzers, allowing algal mats to overgrow eelgrass beds. This shore crab feedback mechanism could become self-generating by promoting the growth of its own nursery habitat (algal mats) and by decreasing the nursery habitat (seagrass meadow) of its dominant predator (cod). This double feedback-loop is supported by a strong increase of shore crab abundance in the last decades and may partly explain the regime shift in vegetation observed

  7. 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.

  8. 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.

  9. Seed Predation by the Shore Crab Carcinus maenas: A Positive Feedback Preventing Eelgrass Recovery?

    PubMed

    Infantes, Eduardo; Crouzy, Caroline; Moksnes, Per-Olav

    2016-01-01

    There is an increasing interest to restore the ecosystem services that eelgrass provides, after their continuous worldwide decline. Most attempts to restore eelgrass using seeds are challenged by very high seed losses and the reasons for these losses are not all clear. We assess the impact of predation on seed loss and eelgrass establishment, and explore methods to decrease seed loss during restoration in the Swedish northwest coast. In a laboratory study we identified three previously undescribed seed predators, the shore crab Carcinus maenas, the hermit crab Pagurus bernhardus and the sea urchin Strongylocentrotus droebachiensis, of which shore crabs consumed 2-7 times more seeds than the other two species. The importance of shore crabs as seed predators was supported in field cage experiments where one enclosed crab caused 73% loss of seeds over a 1-week period on average (~ 21 seeds per day). Seedling establishment was significantly higher (14%) in cages that excluded predators over an 8-month period than in uncaged plots and cages that allowed predators but prevented seed-transport (0.5%), suggesting that seed predation constitutes a major source of seed loss in the study area. Burying the seeds 2 cm below the sediment surface prevented seed predation in the laboratory and decreased predation in the field, constituting a way to decrease seed loss during restoration. Shore crabs may act as a key feedback mechanism that prevent the return of eelgrass both by direct consumption of eelgrass seeds and as a predator of algal mesograzers, allowing algal mats to overgrow eelgrass beds. This shore crab feedback mechanism could become self-generating by promoting the growth of its own nursery habitat (algal mats) and by decreasing the nursery habitat (seagrass meadow) of its dominant predator (cod). This double feedback-loop is supported by a strong increase of shore crab abundance in the last decades and may partly explain the regime shift in vegetation observed along

  10. 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

  11. 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

  12. 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

  13. Residual analysis in determining the error structure in enzyme kinetic data. Simulation experiments and observations on Carcinus maenas phosphofructokinase.

    PubMed

    Little, D I; Poat, P C; Giles, I G

    1982-06-01

    The nature of the experimental error in the initial velocities of an enzyme-catalysed reaction is required if meaningful least-squares regression is to be applied. When a rate equation more complex that that of Michaelis and Menten is to be solved least-squares techniques are the method of choice and so determination of the error structure becomes mandatory. The use of residual analysis and Tukey's T statistics to determine the weights to use are described. This method has the advantage of requiring no additional experimentation over that required for the primary investigation. Using data obtained for Carcinus maenas phosphofructokinase the variance was found to increase with velocity and was approximated by either an empirical power function, var (vi) alpha vi1.8 or by the function, var (vi) alpha 0.007 + vi2. The latter function is preferred and suggests that the data contains both a constant absolute error and a constant percentage error component.

  14. Lack of adult novel northern lineages of invasive green crab Carcinus maenas along much of the northern US Atlantic coast

    PubMed Central

    Williams, Larissa M.; Nivison, Camilla L.; Ambrose, William G.; Dobbin, Rebecca; Locke, William L.

    2017-01-01

    Introduced over 200 yr ago to the east coast of North America, Carcinus maenas now ranges from New York to Newfoundland. In the 1980s, a secondary invasion of European lineages, termed northern haplotypes, occurred in Nova Scotia. Young-of-the-year sampled in 2007 revealed that northern haplotypes were present in low frequencies at several northwestern Atlantic sites as far south as New York; a model predicted an increase in their range and frequency over time. We collected samples in 2013 and 2014 to determine the haplotypes of adult crabs from New York to Nova Scotia. Six haplotypes, encompassing previously identified northern and southern haplotypes, 1 novel southern haplotype, and 1 Scandinavian haplotype, were identified in 275 crabs sampled at 11 sites. Northern haplotypes were only found in Nova Scotia, Beals Island (Maine), and Mount Desert Island (Maine) at a frequency of 60, 8, and 24%, respectively; remaining sites were predominantly composed of a previously identified southern haplotype. Northern haplotypes are limited in adult crabs to Mount Desert Island and north, indicating that the southern haplotype is selectively favored at some point during their life history, recruitment of northern larvae is limited south of Mount Desert Island, or entire year-classes post-2007 were lost. Our results do not support the predictions of an increase in the range and frequency of northern haplotypes, at least among adults, and indicate that a more complete knowledge of factors affecting C. maenas life stages is necessary to understand the current distribution of haplotypes. PMID:28127110

  15. Lack of adult novel northern lineages of invasive green crab Carcinus maenas along much of the northern US Atlantic coast.

    PubMed

    Williams, Larissa M; Nivison, Camilla L; Ambrose, William G; Dobbin, Rebecca; Locke, William L

    2015-01-01

    Introduced over 200 yr ago to the east coast of North America, Carcinus maenas now ranges from New York to Newfoundland. In the 1980s, a secondary invasion of European lineages, termed northern haplotypes, occurred in Nova Scotia. Young-of-the-year sampled in 2007 revealed that northern haplotypes were present in low frequencies at several northwestern Atlantic sites as far south as New York; a model predicted an increase in their range and frequency over time. We collected samples in 2013 and 2014 to determine the haplotypes of adult crabs from New York to Nova Scotia. Six haplotypes, encompassing previously identified northern and southern haplotypes, 1 novel southern haplotype, and 1 Scandinavian haplotype, were identified in 275 crabs sampled at 11 sites. Northern haplotypes were only found in Nova Scotia, Beals Island (Maine), and Mount Desert Island (Maine) at a frequency of 60, 8, and 24%, respectively; remaining sites were predominantly composed of a previously identified southern haplotype. Northern haplotypes are limited in adult crabs to Mount Desert Island and north, indicating that the southern haplotype is selectively favored at some point during their life history, recruitment of northern larvae is limited south of Mount Desert Island, or entire year-classes post-2007 were lost. Our results do not support the predictions of an increase in the range and frequency of northern haplotypes, at least among adults, and indicate that a more complete knowledge of factors affecting C. maenas life stages is necessary to understand the current distribution of haplotypes.

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

    PubMed Central

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

    2013-01-01

    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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Genomic evidence of hybridization between two independent invasions of European green crab (Carcinus maenas) in the Northwest Atlantic.

    PubMed

    Jeffery, N W; DiBacco, C; Wringe, B F; Stanley, R R E; Hamilton, L C; Ravindran, P N; Bradbury, I R

    2017-09-01

    Invasive species have been associated with significant negative impacts in their introduced range often outcompeting native species, yet the long-term evolutionary dynamics of biological invasions are not well understood. Hybridization, either among waves of invasion or between native and introduced populations, could alter the ecological and evolutionary impacts of invasions yet has rarely been studied in marine invasive species. The European green crab (Carcinus maenas) invaded eastern North America twice from northern and southern locations in its native range. Here we examine the frequency of hybridization among these two distinct invasions at locations from New Jersey, USA to Newfoundland, Canada using restriction-site-associated DNA sequencing (RAD-seq), microsatellite loci and cytochrome c oxidase subunit I mitochondrial DNA (mtDNA) sequences. We used Bayesian clustering and hybrid assignment analyses to investigate hybridization between the northern and southern populations. Of the samples analyzed, six locations contained at least one hybrid individual, while two locations were characterized by extensive hybridization, with 95% of individuals collected from Placentia Bay, Newfoundland being hybrids (mostly F2) and 90% of individuals from Kejimkujik, Nova Scotia being classified as hybrids, mostly backcrosses to the northern ecotype. The presence of both F2 hybrids and backcrossed individuals suggests that these hybrids are viable and introgression is occurring between invasions. Our results provide insight into the demographic and evolutionary consequences of hybridization between independent invasions, and will inform the management of green crabs in eastern North America.

  3. RAD sequencing reveals genomewide divergence between independent invasions of the European green crab (Carcinus maenas) in the Northwest Atlantic.

    PubMed

    Jeffery, Nicholas W; DiBacco, Claudio; Van Wyngaarden, Mallory; Hamilton, Lorraine C; Stanley, Ryan R E; Bernier, Renée; FitzGerald, Jennifer; Matheson, K; McKenzie, C H; Nadukkalam Ravindran, Praveen; Beiko, Robert; Bradbury, Ian R

    2017-04-01

    Genomic studies of invasive species can reveal both invasive pathways and functional differences underpinning patterns of colonization success. The European green crab (Carcinus maenas) was initially introduced to eastern North America nearly 200 years ago where it expanded northwards to eastern Nova Scotia. A subsequent invasion to Nova Scotia from a northern European source allowed further range expansion, providing a unique opportunity to study the invasion genomics of a species with multiple invasions. Here, we use restriction-site-associated DNA sequencing-derived SNPs to explore fine-scale genomewide differentiation between these two invasions. We identified 9137 loci from green crab sampled from 11 locations along eastern North America and compared spatial variation to mitochondrial COI sequence variation used previously to characterize these invasions. Overall spatial divergence among invasions was high (pairwise FST ~0.001 to 0.15) and spread across many loci, with a mean FST ~0.052 and 52% of loci examined characterized by FST values >0.05. The majority of the most divergent loci (i.e., outliers, ~1.2%) displayed latitudinal clines in allele frequency highlighting extensive genomic divergence among the invasions. Discriminant analysis of principal components (both neutral and outlier loci) clearly resolved the two invasions spatially and was highly correlated with mitochondrial divergence. Our results reveal extensive cryptic intraspecific genomic diversity associated with differing patterns of colonization success and demonstrates clear utility for genomic approaches to delineating the distribution and colonization success of aquatic invasive species.

  4. 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.

  5. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. A remarkable, precisely timed release of hyperglycemic hormone from endocrine cells in the gut is associated with ecdysis in the crab Carcinus maenas.

    PubMed

    Chung, J S; Dircksen, H; Webster, S G

    1999-11-09

    Molting or ecdysis is the most fundamentally important process in arthropod life history, because shedding of the exoskeleton is an absolute prerequisite for growth and metamorphosis. Although the hormonal mechanisms driving ecdysis in insects have been studied extensively, nothing is known about these processes in crustaceans. During late premolt and during ecdysis in the crab Carcinus maenas, we observed a precise and reproducible surge in hemolymph hyperglycemic hormone (CHH) levels, which was over 100-fold greater than levels seen in intermolt animals. The source of this hormone surge was not from the eyestalk neurosecretory tissues but from previously undescribed endocrine cells (paraneurons), in defined areas of the foregut and hindgut. During premolt (the only time when CHH is expressed by these tissues), the gut is the largest endocrine tissue in the crab. The CHH surge, which is a result of an unusual, almost complete discharge of the contents of the gut endocrine cell, regulates water and ion uptake during molting, thus allowing the swelling necessary for successful ecdysis and the subsequent increase in size during postmolt. This study defines an endocrine brain/gut axis in the arthropods. We propose that the ionoregulatory process controlled by CHH may be common to arthropods, in that, for insects, a similar mechanism seems to be involved in antidiuresis. It also seems likely that a cascade of very precisely coordinated release of (neuro) hormones controls ecdysis.

  14. 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

  15. 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

    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.

  16. Cadmium bioaccumulates after acute exposure but has no effect on locomotion or shelter-seeking behaviour in the invasive green shore crab (Carcinus maenas).

    PubMed

    Blewett, Tamzin A; Newton, Dustin; Flynn, Shannon L; Alessi, Daniel S; Goss, Greg G; Hamilton, Trevor J

    2017-01-01

    Cadmium (Cd(2+)) is a non-essential metal ubiquitous in the environment due to industrial processes. However, little is known regarding the ability of Cd(2+) to impact the behaviour of aquatic animals in receiving environments. Green shore crabs (Carcinus maenas) were exposed to waterborne Cd(2+) [control (no Cd(2+)), low (0.30 μmol/L), medium (3.3 μmol/L) and high (63 μmol/L)], for 24 h, then, crabs were placed in an open field and shelter test to determine potential changes in locomotion and preference for shelter. Tissues (gill, haemolymph, stomatogastric ganglion) were taken for bioaccumulation analysis of Cd(2+) and ion content. Behavioural testing was recorded with a motion-tracking software system and showed no impact of Cd(2+) on any variable in either of the tests used. All three tissues accumulated Cd(2+) in a concentration-dependent manner. Crabs exposed to low Cd(2+) showed a small but significant decrease in haemolymph Ca(2+), however, this effect was not present at higher Cd(2+) exposures. Overall, the results indicate that short-term Cd(2+) exposure, and the resulting Cd(2+) accumulation, had no effect on locomotor and anxiety-related behaviour of green shore crabs.

  17. Inter-population variability in the reproductive morphology of the shore crab (Carcinus maenas): evidence of endocrine disruption in a marine crustacean?

    PubMed

    Brian, Jayne V

    2005-04-01

    Environmental contaminants that are capable of causing endocrine disrupting effects are currently a major cause for concern. These chemicals are known to influence the reproductive development of vertebrates by mimicking or antagonising the actions of endogenous hormones. However, little is known regarding their potential effects on invertebrates. Here we examine variations in the reproductive morphology of the shore crab (Carcinus maenas) for evidence of endocrine disruption. Crabs were collected from a number of sites comprising a putative gradient of exposure to endocrine disrupting chemicals. Patterns of inter-population variability in the expression of sexually dimorphic traits were then examined for evidence of hormone disruption. Extensive variability was detected and patterns of chelal morphology were consistent with the gradient of endocrine disruption. However, overall, the patterns of morphological variability were not consistent with hormonally-mediated effects. This suggests that shore crabs are not susceptible to the same type of endocrine disrupting effects that have been detected in vertebrates, which are most commonly mediated via the oestrogen receptor. However, the potential for androgenic effects on crustacean morphology are discussed.

  18. Interspecific Hybridization and Mitochondrial Introgression in Invasive Carcinus Shore Crabs

    PubMed Central

    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

  19. Effects of elevated seawater pCO2 on gene expression patterns in the gills of the green crab, Carcinus maenas

    PubMed Central

    2011-01-01

    Background The green crab Carcinus maenas is known for its high acclimation potential to varying environmental abiotic conditions. A high ability for ion and acid-base regulation is mainly based on an efficient regulation apparatus located in gill epithelia. However, at present it is neither known which ion transport proteins play a key role in the acid-base compensation response nor how gill epithelia respond to elevated seawater pCO2 as predicted for the future. In order to promote our understanding of the responses of green crab acid-base regulatory epithelia to high pCO2, Baltic Sea green crabs were exposed to a pCO2 of 400 Pa. Gills were screened for differentially expressed gene transcripts using a 4,462-feature microarray and quantitative real-time PCR. Results Crabs responded mainly through fine scale adjustment of gene expression to elevated pCO2. However, 2% of all investigated transcripts were significantly regulated 1.3 to 2.2-fold upon one-week exposure to CO2 stress. Most of the genes known to code for proteins involved in osmo- and acid-base regulation, as well as cellular stress response, were were not impacted by elevated pCO2. However, after one week of exposure, significant changes were detected in a calcium-activated chloride channel, a hyperpolarization activated nucleotide-gated potassium channel, a tetraspanin, and an integrin. Furthermore, a putative syntaxin-binding protein, a protein of the transmembrane 9 superfamily, and a Cl-/HCO3- exchanger of the SLC 4 family were differentially regulated. These genes were also affected in a previously published hypoosmotic acclimation response study. Conclusions The moderate, but specific response of C. maenas gill gene expression indicates that (1) seawater acidification does not act as a strong stressor on the cellular level in gill epithelia; (2) the response to hypercapnia is to some degree comparable to a hypoosmotic acclimation response; (3) the specialization of each of the posterior gill

  20. 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.

  1. An x-ray absorption near edge structure spectroscopy study of metal coordination in Co(II)-substituted Carcinus maenas hemocyanin.

    PubMed Central

    Della Longa, S; Bianconi, A; Palladino, L; Simonelli, B; Congiu Castellano, A; Borghi, E; Barteri, M; Beltramini, M; Rocco, G P; Salvato, B

    1993-01-01

    High-resolution x-ray absorption near edge structure spectroscopy was used to characterize the metal sites in three different cobalt-substituted derivatives of Carcinus maenas hemocyanin (Hc), including a mononuclear cobalt, a dinuclear cobalt and a copper-cobalt hybrid derivative. Co(II) model complexes with structures exemplifying octahedral, trigonal bipyramidal, pseudo-tetrahedral, and square planar geometries were also studied. The results provide structural information about the metal binding site(s) in the Co-Hcs that extend earlier results from EPR and optical spectroscopy (Bubacco et al. 1992. Biochemistry. 31: 9294-9303). Experimental spectra were compared to those calculated for atomic clusters of idealized geometry, generated using a multiple scattering approach. The energy of the dipole forbidden 1s-->3d transition and of the absorption edge in the spectra for all cobalt Hc derivatives confirmed the cobaltous oxidation state which rules out the presence of an oxygenated site. Comparisons between data and simulations showed that the mononuclear and dinuclear Co(II) derivatives, as well as the hybrid derivative, contain four-coordinate Co(II) in distorted tetrahedral sites. Although the spectra for Co(II) in dinuclear metal sites more closely resemble the simulated spectrum for a tetrahedral complex than do spectra for the mononuclear derivative, the Co(II) sites in all derivatives are very similar. The Cu K-edge high resolution x-ray absorption near edge structure spectrum of the hybrid Cu-Co-Hc resembles that of deoxy-Hc demonstrating the presence of three-coordinate Cu(I). PMID:8312502

  2. 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

  3. Identification and developmental expression of mRNAs encoding putative insect cuticle hardening hormone, bursicon in the green shore crab Carcinus maenas.

    PubMed

    Wilcockson, David C; Webster, Simon G

    2008-03-01

    Bursicon is the ultimate hormone in insect ecdysis, which is involved in cuticle hardening. Here we show that mRNAs encoding the heterodimeric cystine knot protein bursicon (Burs alpha, beta), are present in crustaceans, suggesting ubiquity of this hormone in arthropods. We firstly report the cloning, sequencing of mRNAs encoding subunits from the water flea, Daphnia arenata and the CNS of the crab, Carcinus maenas, in comparison with insect bursicon subunits. Expression patterns of alpha and beta burs mRNAs were examined by in-situ hybridisation (ISH) and quantitative RT-PCR. In the thoracic ganglion, burs alpha and beta mRNAs were completely colocalised in neurones expressing crustacean cardioactive peptide (CCAP). However, in the brain and eyestalk, bursicon transcripts were never observed, despite a complex expression pattern of CCAP interneurones. Patterns of expression of burs alpha and beta mRNAs were constitutive during the moult cycle of adult crabs, in stark contrast to the situation in insects. Whilst copy numbers of burs beta transcripts closely matched those of CCAP, those of burs alpha mRNA were around 3-fold higher than burs beta. This pattern was apparent during embryogenesis, where bursicon transcripts were first observed at around 50% development-the same time as first expression of CCAP mRNA. Transcript ratios (burs alpha: beta) increased during development. Our studies have shown, for the first time, that bursicon mRNAs are expressed in identified neurones in the nervous system of crustaceans. These findings will now promote further investigation into the functions of bursicon during the moult cycle and development of crustaceans.

  4. 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.

  5. An x-ray absorption near edge structure spectroscopy study of metal coordination in Co(II)-substituted Carcinus maenas hemocyanin.

    PubMed

    Della Longa, S; Bianconi, A; Palladino, L; Simonelli, B; Congiu Castellano, A; Borghi, E; Barteri, M; Beltramini, M; Rocco, G P; Salvato, B

    1993-12-01

    High-resolution x-ray absorption near edge structure spectroscopy was used to characterize the metal sites in three different cobalt-substituted derivatives of Carcinus maenas hemocyanin (Hc), including a mononuclear cobalt, a dinuclear cobalt and a copper-cobalt hybrid derivative. Co(II) model complexes with structures exemplifying octahedral, trigonal bipyramidal, pseudo-tetrahedral, and square planar geometries were also studied. The results provide structural information about the metal binding site(s) in the Co-Hcs that extend earlier results from EPR and optical spectroscopy (Bubacco et al. 1992. Biochemistry. 31: 9294-9303). Experimental spectra were compared to those calculated for atomic clusters of idealized geometry, generated using a multiple scattering approach. The energy of the dipole forbidden 1s-->3d transition and of the absorption edge in the spectra for all cobalt Hc derivatives confirmed the cobaltous oxidation state which rules out the presence of an oxygenated site. Comparisons between data and simulations showed that the mononuclear and dinuclear Co(II) derivatives, as well as the hybrid derivative, contain four-coordinate Co(II) in distorted tetrahedral sites. Although the spectra for Co(II) in dinuclear metal sites more closely resemble the simulated spectrum for a tetrahedral complex than do spectra for the mononuclear derivative, the Co(II) sites in all derivatives are very similar. The Cu K-edge high resolution x-ray absorption near edge structure spectrum of the hybrid Cu-Co-Hc resembles that of deoxy-Hc demonstrating the presence of three-coordinate Cu(I).

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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.

  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.

  12. Increase in density of genetically diverse invasive Asian shore crab (Hemigrapsus sanguineus) populations in the Gulf of Maine

    PubMed Central

    Williams, Larissa M.

    2017-01-01

    Hemigrapsus sanguineus, the Asian shore crab, has rapidly replaced Carcinus maenas, the green crab, as the most abundant crab on rocky shores in the northwest Atlantic since its introduction to the United States (USA) in 1988. The northern edge of this progressing invasion is the Gulf of Maine, where Asian shore crabs are only abundant in the south. We compared H. sanguineus population densities to those from published 2005 surveys and quantified genetic variation using the cytochrome c oxidase subunit I gene. We found that the range of H. sanguineus had extended northward since 2005, that population density had increased substantially (at least 10-fold at all sites), and that Asian shore crabs had become the dominant intertidal crab species in New Hampshire and southern Maine. Despite the significant increase in population density of H. sanguineus, populations only increased by a factor of 14 in Maine compared to 70 in southern New England, possibly due to cooler temperatures in the Gulf of Maine. Genetically, populations were predominantly composed of a single haplotype of Japanese, Korean, or Taiwanese origin, although an additional seven haplotypes were found. Six of these haplotypes were of Asian origin, while two are newly described. Large increases in population sizes of genetically diverse individuals in Maine will likely have a large ecological impact, causing a reduction in populations of mussels, barnacles, snails, and other crabs, similar to what has occurred at southern sites with large populations of this invasive crab species. PMID:28919836

  13. Increase in density of genetically diverse invasive Asian shore crab (Hemigrapsus sanguineus) populations in the Gulf of Maine.

    PubMed

    Lord, Joshua P; Williams, Larissa M

    2017-04-01

    Hemigrapsus sanguineus, the Asian shore crab, has rapidly replaced Carcinus maenas, the green crab, as the most abundant crab on rocky shores in the northwest Atlantic since its introduction to the United States (USA) in 1988. The northern edge of this progressing invasion is the Gulf of Maine, where Asian shore crabs are only abundant in the south. We compared H. sanguineus population densities to those from published 2005 surveys and quantified genetic variation using the cytochrome c oxidase subunit I gene. We found that the range of H. sanguineus had extended northward since 2005, that population density had increased substantially (at least 10-fold at all sites), and that Asian shore crabs had become the dominant intertidal crab species in New Hampshire and southern Maine. Despite the significant increase in population density of H. sanguineus, populations only increased by a factor of 14 in Maine compared to 70 in southern New England, possibly due to cooler temperatures in the Gulf of Maine. Genetically, populations were predominantly composed of a single haplotype of Japanese, Korean, or Taiwanese origin, although an additional seven haplotypes were found. Six of these haplotypes were of Asian origin, while two are newly described. Large increases in population sizes of genetically diverse individuals in Maine will likely have a large ecological impact, causing a reduction in populations of mussels, barnacles, snails, and other crabs, similar to what has occurred at southern sites with large populations of this invasive crab species.

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

    USDA-ARS?s Scientific Manuscript database

    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. Spectroscopic properties of Carcinus aestuarii hemocyanin and its structural subunits

    NASA Astrophysics Data System (ADS)

    Dolashka-Angelova, Pavlina; Hristova, Rumiyana; Stoeva, Stanka; Voelter, Wolfgang

    1999-12-01

    Hemocyanin (Hc) of Carcinus aestuarii contains three major and one minor electrophoretically separable polypeptide chains which were purified by fast protein liquid chromatography (FPLC) ion exchange chromatography. N-terminal amino acid sequences of four structural subunits (SSs) from C. aestuarii were compared with known N-terminal sequences from other arthropodan hemocyanins. The conformational changes, induced by various treatments, were monitored by far UV, CD and fluorescence spectroscopy. The critical temperatures for the structural subunits, Tc, determined by fluorescence spectroscopy, are in the region of 52-59°C and coincide with the melting temperatures, Tm (49-55°C), determined by CD spectroscopy. The free energy of stabilization in water, Δ GDH 2O , toward guanidinium hydrochloride is about 1.3 times higher for the dodecameric Hc as compared to the isolated subunits and about one time higher for Ca1, comparing with other SSs. The studies reveal that the conformational stability of the native dodecamer towards various denaturants (temperature and guanidinium hydrochloride) indicate that the quaternary structure is stabilized by oligomerization between structural subunits, and the possibility of a structural role of the sugar mojeties cannot be excluded.

  16. Acidification of the gill cells of the shore crab Carcinus mediterraneus: Its physiological significance

    NASA Astrophysics Data System (ADS)

    Lucu, Č.; Siebers, D.

    1995-03-01

    In a preparation of isolated gills of the shore crab Carcinus mediterraneus perfused with dilute sea water (pH 8.1, 200 mM Na+) which was identical to the bathing solution of the gill, acidification of the collected perfusate was observed. Acidification was not affected by 10-4 M EIPA (5-[N-ethyl-N-isopropyl]amiloride), a strong inhibitor of Na+/H+ exchange. However, in the presence of 10-4 M acetazolamide, acidification was greatly blocked. The significant decrease of the acid load of the perfusate is considered to be a result of inhibition of the branchial intracellular carbonic anhydrase catalyzing the formation of H+ ions.

  17. 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.

  18. [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.

  19. Effects of temperature on cellular and biochemical parameters in the crab Carcinus aestuarii (Crustacea, Decapoda).

    PubMed

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

    2011-06-01

    The effects of temperature on cellular and biochemical parameters of the crab Carcinus aestuarii were evaluated. Crabs were kept for 7 days at 4, 17 (reference value) and 30 °C (salinity of 35 psu), and total haemocyte count (THC), haemocyte volume, haemocyte proliferation, phenoloxidase (PO) activity in both haemocyte lysate (HL) and cell-free haemolymph (CFH), CFH total protein and glucose levels, superoxide dismutase (SOD) and catalase (CAT) activities in both gills and digestive gland were evaluated. The lowest and the highest temperature significantly decreased THC, whereas haemocyte volume and haemolymph glucose concentration did not differ significantly among experimental conditions. Haemolymph protein concentration significantly reduced in crabs maintained at 30 °C, when compared with that of animals kept at 4 and 17 °C. Haemocyte proliferation increased significantly in crabs kept at 4 and 30 °C, when compared with that of crabs held at 17 °C. Likewise, a significantly higher PO activity was recorded in CFH from crabs kept at 4 and 30 °C, than in control crabs. Conversely, PO activity did not vary significantly in HL. With regard to antioxidant enzyme activities, a significant decrease in CAT activity was observed in gills from crabs kept at 4 °C, when compared to that of crabs kept at 17 °C and 30 °C. Results obtained demonstrated that the highest and lowest temperature tested influenced crab biological responses, and indicated that C. aestuarii modulated its cellular and biochemical parameters (mainly haemocyte proliferation, CFH protein concentrations and CFH PO activity) in order to cope with temperature. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. 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 ...

  1. Foraging behaviour and mutual interference in the Mediterranean shore crab, Carcinus aestuarii, preying upon the immigrant mussel Musculista senhousia

    NASA Astrophysics Data System (ADS)

    Mistri, M.

    2003-01-01

    Predator-prey dynamics between the Mediterranean shore crab Carcinus aestuarii and the immigrant mussel Musculista senhousia were examined in laboratory experiments to assess the effects of varying predator and prey densities upon predator foraging rates and prey survival. The factorial design involved three predator and three prey densities, with four trials per treatment combination. Functional responses were differentiated statistically by analysis of the exponent β of a general functional response model. Shore crabs displayed type II (decelerating rise to an upper asymptote) inversely density-dependent functional responses at low and moderate predator densities, while a non-traditional model was probably more appropriate at high predator density. No density-dependent refuge was observed for M. senhousia, whereas, at high predator density, mutual interference among crabs was evident and prey mortality was lowered. Mediterranean shore crab's combined functional and interference response, by affecting foraging rates, was important to the outcome of interactions between predators and the bivalve prey, and might play an important role in determining crab's predatory behaviour and dispersion, and prey persistence, in the field.

  2. Genetics

    USDA-ARS?s Scientific Manuscript database

    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

    USDA-ARS?s Scientific Manuscript database

    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. 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. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. 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

  6. Oxidized derivatives of Octopus vulgaris and Carcinus aestuarii hemocyanins at pH 7.5 and related models by x-ray absorption spectroscopy.

    PubMed Central

    Borghi, Elena; Solari, Pier Lorenzo; Beltramini, Mariano; Bubacco, Luigi; Di Muro, Paolo; Salvato, Benedetto

    2002-01-01

    The binuclear copper sites of the met and met-azido derivatives of Octopus vulgaris and Carcinus aestuarii hemocyanins at pH 7.5 were characterized by high-resolution x-ray absorption spectroscopy in the low energy region (XANES) and in the higher region (EXAFS). The accuracy of the analysis of the data was tested with two mononuclear and six binuclear copper(II) complexes of the poly(benzimidazole) ligand systems 2-BB, L-5,5 and L-6,6 (Casella et al., 1993, Inorg. Chem. 32:2056-2067; 1996, Inorg. Chem. 35:1101-1113). Their structural and reactivity properties are related to those of the protein's derivatives. The results obtained for those models with resolved x-ray structure (the 2-BB-aquo and azido mononuclear complexes, and the binuclear L-5,5 Cu(II)-bis(hydroxo) (Casella et al., unpublished)), extends the validity of our approach to the other poly(benzimidazole)-containing complexes and to the hemocyanin derivatives. Comparison between the protein's and the complexes' data, support a description of the met-derivatives as a five-coordinated O-bridged binuclear copper(II) center and favors, for both species, a bis(hydroxo) structure with a 3-A Cu-Cu distance. For O. vulgaris met-azido derivative a mu-1,3 bridging mode for the ligand appears the most likely. The structural situation of C. aestuarii met-azido-derivative is less clear: a mu-1,1 mode is favored, but a terminal mode cannot be excluded. PMID:12023249

  7. 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. © 2014 John Wiley & Sons Ltd.

  8. Genetic Counseling

    MedlinePlus

    ... Home > Pregnancy > Before or between pregnancies > Genetic counseling Genetic counseling E-mail to a friend Please fill ... a genetic counselor in your area. What is genetic counseling? Genetic counseling helps you understand how genes , ...

  9. [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.

  10. 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. © 2014 John Wiley & Sons Ltd.

  11. 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

  12. 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).

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. Genetic Counseling

    MedlinePlus

    ... Genetic Counseling Genomic Testing Pathogen Genomics Epidemiology Resources Genetic Counseling Recommend on Facebook Tweet Share Compartir In ... informed decisions about testing and treatment. Reasons for Genetic Counseling There are many reasons that people go ...

  19. 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.

  20. 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.

  1. 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.

  2. 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 ...

  3. Genetic counseling

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000510.htm Genetic counseling To use the sharing features on this ... cystic fibrosis or Down syndrome. Who May Want Genetic Counseling? It is up to you whether or ...

  4. Genetic Manipulation

    ERIC Educational Resources Information Center

    Klein, David

    1973-01-01

    Knowledge of genetic manipulations opens the door to ambitious possibilities of inhabiting the world with genetically perfect human beings. Legal, technological and social problems are involved. Attempts must be made to identify hereditary complaints in individuals. (PS)

  5. 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 ...

  6. New Genetics

    MedlinePlus

    ... Organisms RNA Interference The New Genetics is a science education booklet explains the role of genes in health and disease, the basics of DNA and its molecular cousin RNA, and new directions in genetic research. ...

  7. 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

  8. Genetic modification and genetic determinism.

    PubMed

    Resnik, David B; Vorhaus, Daniel B

    2006-06-26

    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.

  9. 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.

  10. 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.

  11. 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.

  12. Genetic Alliance

    MedlinePlus

    ... educate consumers around appropriate testing and public health services, and help individuals navigate the complex health care delivery system. Highlights Genetic Alliance Internship Program Learn about ...

  13. Spontaneous alternation in marine crabs: invasive versus native species.

    PubMed

    Ramey, Patricia Ann; Teichman, Elizabeth; Oleksiak, Justin; Balci, Fuat

    2009-09-01

    Organisms ranging from paramecia to humans tend to explore places that have been least recently explored, which is referred to as spontaneous alternation. Although organisms rely on different sources of information in alternating between places, the emergent behavioral pattern is likely advantageous during exploration and foraging. Under this rationale, continuous spontaneous alternation performance of the invasive green crab, Carcinus maenas was assessed and compared with the native blue crab, Callinectes sapidus in a plus-maze submerged in seawater. For the first time spontaneous alternation behavior was demonstrated in Crustacea (i.e., C. maenas) and significant interspecific differences in alternation performance were observed between the invasive versus the native species. Carcinus maneas exhibited a pronouncedly higher spontaneous alternation performance than C. sapidus. Carcinus maneas on average alternated at levels higher than chance, which was not the case for C. sapidus. These observations point to an additional behavioral mechanism that might result in the competitive success of green crabs over blue crabs in areas where they co-occur. Most of the subjects exhibited asymptotic alternation performance from the onset; there was no improvement in their performance over the course of the experimental session. This finding implies the innate nature of this behavioral policy.

  14. 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)

  15. Genetic algorithms

    SciTech Connect

    Grefenstette, J.J.

    1994-12-31

    Genetic algorithms solve problems by using principles inspired by natural population genetics: They maintain a population of knowledge structures that represent candidate solutions, and then let that population evolve over time through competition and controlled variation. GAs are being applied to a wide range of optimization and learning problems in many domains.

  16. Genetic Counseling.

    ERIC Educational Resources Information Center

    Exceptional Parent, 1987

    1987-01-01

    Information is presented on a number of tests used in genetic counseling (e.g., genetic evaluation, chromosome evaluation, consideration of multifactorial conditions, prenatal testing, and chorionic villus sampling) which help parents with one disabled child make family planning decisions. (CB)

  17. 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)

  18. Genetic principles

    Treesearch

    Ronald P. Overton; David T. Funk

    1989-01-01

    Tree growth is a function of both environment and genetic makeup. All forest management activities during a rotation from establishment to harvest affect the genetic composition and the environment of a stand. Silvicultural practices which fail to take both of these factors into account will reduce forest productivity.

  19. 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)

  20. RNA genetics

    SciTech Connect

    Domingo, E. ); Holland, J.J. . Dept. of Biology); Ahlquist, P. . Dept. of Plant Pathology)

    1988-01-01

    This book contains the proceedings on RNA genetics: Retroviruses, Viroids, and RNA recombination, Volume 2. Topics covered include: Replication of retrovirus genomes, Hepatitis B virus replication, and Evolution of RNA viruses.

  1. Genetic Counseling

    PubMed Central

    Reid, Kathryn J.; Sakati, Nadia; Prichard, Lorraine L.; Schneiderman, Lawrence J.; Jones, Oliver W.; Dixson, Barbara K.

    1976-01-01

    The geographic distribution of County Health Department clinic facilities in the state of California has made it readily possible to establish a regionalized program for genetic counseling services, using public health nurses as a major source of case-finding. From both consumer and health professional standpoints, regionalized satellite genetic counseling clinics have been successful, and in particular, the effectiveness of public health nurses in identifying clinical genetic problems is readily apparent. Long-term follow-up reinforcement of genetic counseling appears to be an important conclusion from these studies. It is our suggestion that reinforcement of counseling would best be accomplished through the health team member (physician, nurse and so forth) following the patient or family rather than through the consulting geneticist. PMID:946335

  2. Genetics (image)

    MedlinePlus

    ... chromosomes to their child, 22 autosomal and 1 sex chromosome. The inheritance of genetic diseases, abnormalities, or traits ... chromosome the abnormal gene resides on (autosomal or sex chromosome), and by whether the gene itself is dominant ...

  3. 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

  4. Genetic Screening

    PubMed Central

    Burke, Wylie; Tarini, Beth; Press, Nancy A.; Evans, James P.

    2011-01-01

    Current approaches to genetic screening include newborn screening to identify infants who would benefit from early treatment, reproductive genetic screening to assist reproductive decision making, and family history assessment to identify individuals who would benefit from additional prevention measures. Although the traditional goal of screening is to identify early disease or risk in order to implement preventive therapy, genetic screening has always included an atypical element—information relevant to reproductive decisions. New technologies offer increasingly comprehensive identification of genetic conditions and susceptibilities. Tests based on these technologies are generating a different approach to screening that seeks to inform individuals about all of their genetic traits and susceptibilities for purposes that incorporate rapid diagnosis, family planning, and expediting of research, as well as the traditional screening goal of improving prevention. Use of these tests in population screening will increase the challenges already encountered in genetic screening programs, including false-positive and ambiguous test results, overdiagnosis, and incidental findings. Whether this approach is desirable requires further empiric research, but it also requires careful deliberation on the part of all concerned, including genomic researchers, clinicians, public health officials, health care payers, and especially those who will be the recipients of this novel screening approach. PMID:21709145

  5. Genetic counseling.

    PubMed

    Pina-Neto, João Monteiro de

    2008-08-01

    The objective of this review of genetic counseling (GC) is to describe the current concepts and philosophical and ethical principles accepted by the great majority of countries and recommended by the World Health Organization, the stages of the process, its results and the psychological impact that a genetic disease has on a family. The concepts presented are based on an historical synthesis of the literature on GC since the 1930s until today, and the articles cited represent the most important research published which today provides the foundation for the theory and practice of GC. The modern definition of GC is a process of communication that deals with the human problems related with the occurrence of a genetic disease in a family. It is of fundamental importance that health professionals are aware of the psychological aspects triggered by genetic diseases and the ways in which these can be managed. In the field of human and medical genetics we are still living in a phase in which technical and scientific aspects predominate, with little emphasis on the study of emotional reactions and people's processes of adaptation to these diseases, which leads to clients having a low level of understanding of the events that have taken place, with negative consequences for family life and for society. The review concludes by discussing the need to refer families with genetic diseases for GC and the need for professionals working in this area to invest more in humanizing care and developing non-directive psychological GC techniques.

  6. Genetic screening

    PubMed Central

    Andermann, Anne; Blancquaert, Ingeborg

    2010-01-01

    Abstract OBJECTIVE To provide a primer for primary care professionals who are increasingly called upon to discuss the growing number of genetic screening services available and to help patients make informed decisions about whether to participate in genetic screening, how to interpret results, and which interventions are most appropriate. QUALITY OF EVIDENCE As part of a larger research program, a wide literature relating to genetic screening was reviewed. PubMed and Internet searches were conducted using broad search terms. Effort was also made to identify the gray literature. MAIN MESSAGE Genetic screening is a type of public health program that is systematically offered to a specified population of asymptomatic individuals with the aim of providing those identified as high risk with prevention, early treatment, or reproductive options. Ensuring an added benefit from screening, as compared with standard clinical care, and preventing unintended harms, such as undue anxiety or stigmatization, depends on the design and implementation of screening programs, including the recruitment methods, education and counseling provided, timing of screening, predictive value of tests, interventions available, and presence of oversight mechanisms and safeguards. There is therefore growing apprehension that economic interests might lead to a market-driven approach to introducing and expanding screening before program effectiveness, acceptability, and feasibility have been demonstrated. As with any medical intervention, there is a moral imperative for genetic screening to do more good than harm, not only from the perspective of individuals and families, but also for the target population and society as a whole. CONCLUSION Primary care professionals have an important role to play in helping their patients navigate the rapidly changing terrain of genetic screening services by informing them about the benefits and risks of new genetic and genomic technologies and empowering them to

  7. Non-destructive assessment of polycyclic aromatic hydrocarbon (PAH) exposure by fluorimetric analysis of crab urine.

    PubMed

    Koenig, Samuel; Savage, Candida; Kim, Jonathan P

    2008-12-01

    The detection of urinary polycyclic aromatic hydrocarbon (PAH) metabolites by fluorescence spectrophotometry is particularly effective as a practical means to assess PAH exposure in decapod crabs. However, the practical application of this technique has thus far only been tested for the European shore crab (Carcinus maenas) and only a few field studies have been conducted in heavily polluted areas. The present study evaluated the adaptability of this method as a rapid, cost-effective and non-destructive biomonitoring tool for the New Zealand crab species, Macrophthalmus hirtipes (stalk-eyed mud crab). A field gradient could be detected among the sites and different input sources of PAH contamination could be discerned through the differentiation of pyrogenic and petrogenic PAH signatures. The present study shows that the fluorescence screening method is sensitive to relatively low levels of PAH contamination and more broadly applicable to smaller crab species than C. maenas, for which the technique was developed.

  8. 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.

  9. 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

  10. 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.

  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.

  12. 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.

  13. Genetic Counseling

    MedlinePlus

    ... test results and your baby’s risk for genetic conditions. Your counselor works with you and your health care provider to help you make decisions about your baby’s health. Refers you to medical ... that focus on your baby’s condition. A support group is a group of people ...

  14. RNA genetics

    SciTech Connect

    Domingo, E. ); Holland, J.J. . Dept. of Biology); Ahlquist, P. . Dept. of Plant Pathology)

    1988-01-01

    This book contains the proceedings on RNA genetics: RNA-directed virus replication Volume 1. Topics covered include: Replication of the poliovirus genome; Influenza viral RNA transcription and replication; and Relication of the reoviridal: Information derived from gene cloning and expression.

  15. 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)

  16. 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)

  17. Genetic resistances

    USDA-ARS?s Scientific Manuscript database

    Genetic resistance often has been recognized as the most viable mean for limiting soil-borne diseases. In sugar beet, it is only for Beet necrotic yellow vein virus, i.e., rhizomania that a set of fairly different and effective, single-gene resistance is currently available, while for other soil-bor...

  18. 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.

  19. 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

  20. Genetic Testing (For Parents)

    MedlinePlus

    ... Habits for TV, Video Games, and the Internet 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, ...

  1. 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, ...

  2. 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. © 2015 John Wiley & Sons Ltd.

  3. [Genetic amniocentesis].

    PubMed

    Violante Díaz, M; Carrillo Hinojosa, M; García Necoechea, M P; Escobedo Aguirre, F; Lowenberg Favela, E; Ahued Ahued, J R

    1989-04-01

    179 patients were studied by genetic amniocentesis (GA) in sessions of 3 punctures each. This was done in order to follow a prenatal diagnosis (PD) program and study amniotic fluid at the Hospital Regional 20 de Novembre (ISSSTE) between May 1983 and December 1987. The parameters taken were: age, indications, number of sessions, number punctures, echosonographic studies for gestational age, placental insertion, punction site, amniotic fluid volume, blood contamination, failures and handling of the patient. A low incidence of abortion is reported. We don't have cases of dripping of amniotic fluid or transvaginal haemorrhage. Multiple insertion of the needle and placental or vessel lesions of the cord, as causes of a fetal death are still argued if we have in mind avoiding chances; we didn't have those complications in our cases. The percent is low if there are not previous spontaneous abortions. 79% of the amniotic fluid samples were sent between the 15th and 17th weeks of pregnancy. For alpha fetus protein determination 12 and for biochemical studies 1, specially for beta-galactosidase level. This was done at the Biomedical Investigation Institute of the National Autonomous University of Mexico (in parents with generalized gangliosidosis GM1). Even though results were good, the technique has still risks and complications. An ultrasonic study of the procedures made by physicians with trustable experience is needed. Our country has the need to create more Prenatal Genetic Diagnosis Centers.

  4. A genetic engineering approach to genetic algorithms.

    PubMed

    Gero, J S; Kazakov, V

    2001-01-01

    We present an extension to the standard genetic algorithm (GA), which is based on concepts of genetic engineering. The motivation is to discover useful and harmful genetic materials and then execute an evolutionary process in such a way that the population becomes increasingly composed of useful genetic material and increasingly free of the harmful genetic material. Compared to the standard GA, it provides some computational advantages as well as a tool for automatic generation of hierarchical genetic representations specifically tailored to suit certain classes of problems.

  5. 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

  6. Genetic risks and genetic model specification.

    PubMed

    Zheng, Gang; Zhang, Wei; Xu, Jinfeng; Yuan, Ao; Li, Qizhai; Gastwirth, Joseph L

    2016-08-21

    Genetic risks and genetic models are often used in design and analysis of genetic epidemiology studies. A genetic model is defined in terms of two genetic risk measures: genotype relative risk and odds ratio. The impacts of choosing a risk measure on the resulting genetic models are studied in the power to detect association and deviation from Hardy-Weinberg equilibrium in cases using genetic relative risk. Extensive simulations demonstrate that the power of a study to detect associations using odds ratio is lower than that using relative risk with the same value when other parameters are fixed. When the Hardy-Weinberg equilibrium holds in the general population, the genetic model can be inferred by the deviation from Hardy-Weinberg equilibrium in only cases. Furthermore, it is more efficient than that based on the deviation from Hardy-Weinberg equilibrium in all cases and controls. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. 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.

  8. Genetics Home Reference: microphthalmia

    MedlinePlus

    ... including clouding of the lens of the eye ( cataract ) and a narrowed opening of the eye (narrowed ... Genetic Testing Registry: Anophthalmia/Microphthalmia Genetic Testing Registry: Cataract, congenital, with microphthalmia Genetic Testing Registry: Cataract, microphthalmia ...

  9. Genetics Home Reference

    MedlinePlus

    ... MENU Toggle navigation Home Page Search Share: Email Facebook Twitter Home Health Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Genetics Home Reference provides consumer-friendly information about the effects of genetic variation ...

  10. Applying the New Genetics

    ERIC Educational Resources Information Center

    Sorenson, James

    1976-01-01

    New developments in the prediction and treatment of genetic diseases are presented. Genetic counseling and the role of the counselor, and rights of individuals to reproduce versus societal impact of genetic disorders, are discussed. (RW)

  11. Applying the New Genetics

    ERIC Educational Resources Information Center

    Sorenson, James

    1976-01-01

    New developments in the prediction and treatment of genetic diseases are presented. Genetic counseling and the role of the counselor, and rights of individuals to reproduce versus societal impact of genetic disorders, are discussed. (RW)

  12. Genetic aspects and genetic epidemiology of parasomnias.

    PubMed

    Hublin, Christer; Kaprio, Jaakko

    2003-10-01

    Parasomnias are undesirable phenomena associated with sleep. Many of them run in families, and genetic factors have been long suggested to be involved in their occurrence. This article reviews the present knowledge of the genetics of the major classical behavioral parasomnias as well as present results from genetic epidemiological studies. The level and type of evidence for genetic effects varies much from parasomnia to parasomnia. The genetic factors are best established in enuresis, with several linkages to chromosomal loci, but their functions are not so far known. Environmental causes and gene-environment interactions are most probably also of great importance in the origin of complex traits or disorders such as parasomnias.

  13. 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…

  14. 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.

  15. Genetics and genomic medicine.

    PubMed

    Bogaard, Kali; Johnson, Marlene

    2009-01-01

    Genetics is playing an increasingly important role in the diagnosis, monitoring and treatment of diseases, and the expansion of genetics into health care has generated the field of genomic medicine. Health care delivery is shifting away from general diagnostic evaluation toward a generation of therapeutics based on a patient's genetic makeup. Meanwhile, the scientific community debates how best to incorporate genetics and genomic medicine into practice. While obstacles remain, the ultimate goal is to use information generated from the study of human genetics to improve disease treatment, cure and prevention. As the use of genetics in medical diagnosis and treatment increases, health care workers will require an understanding of genetics and genomic medicine.

  16. 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 ...

  17. 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)

  18. 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)

  19. Genetic engineering compared to natural genetic variations.

    PubMed

    Arber, Werner

    2010-11-30

    By comparing strategies of genetic alterations introduced in genetic engineering with spontaneously occurring genetic variation, we have come to conclude that both processes depend on several distinct and specific molecular mechanisms. These mechanisms can be attributed, with regard to their evolutionary impact, to three different strategies of genetic variation. These are local nucleotide sequence changes, intragenomic rearrangement of DNA segments and the acquisition of a foreign DNA segment by horizontal gene transfer. Both the strategies followed in genetic engineering and the amounts of DNA sequences thereby involved are identical to, or at least very comparable with, those involved in natural genetic variation. Therefore, conjectural risks of genetic engineering must be of the same order as those for natural biological evolution and for conventional breeding methods. These risks are known to be quite low. There is no scientific reason to assume special long-term risks for GM crops. For future agricultural developments, a road map is designed that can be expected to lead, by a combination of genetic engineering and conventional plant breeding, to crops that can insure food security and eliminate malnutrition and hunger for the entire human population on our planet. Public-private partnerships should be formed with the mission to reach the set goals in the coming decades.

  20. Genetically engineered foods

    MedlinePlus

    ... a cell of another plant or animal. Function Genetic engineering can be done with plants, animals, or bacteria and other very small organisms. Genetic engineering allows scientists to move desired genes from one ...

  1. 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. ...

  2. 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 ...

  3. Latest Research: Genetic Links

    MedlinePlus

    ... Current Issue Past Issues Feature: Vision Latest Research: Genetic Links Past Issues / Summer 2008 Table of Contents ... laboratories is one way the NEI is expanding genetic testing of eye diseases. Photo courtesy of National ...

  4. Genetics of Hearing Loss

    MedlinePlus

    ... in Latin America Information For… Media Policy Makers Genetics of Hearing Loss Recommend on Facebook Tweet Share ... of hearing loss in babies is due to genetic causes. There are also a number of things ...

  5. Genetics and Man

    ERIC Educational Resources Information Center

    Carter, C. O.

    1973-01-01

    Can genetic evolution be controlled by man in a manner which does not violate a civilized, humane, and democratic ethos? The genetics of health and illhealth and of normal variation are discussed with respect to this question. (PEB)

  6. Genetics Home Reference: SADDAN

    MedlinePlus

    ... PDF Open All Close All Description SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans) is a ... Genetic Testing (1 link) Genetic Testing Registry: Severe achondroplasia with developmental delay and acanthosis nigricans Other Diagnosis ...

  7. Genetic Testing for ALS

    MedlinePlus

    ... Some medical centers may require a neurological exam, psychological assessment and counseling before predictive testing. If a person in the family with ALS has a negative genetic test result (no identified genetic mutation), testing family members ...

  8. Genetics Home Reference: otulipenia

    MedlinePlus

    ... Facebook Share on Twitter Your Guide to Understanding Genetic Conditions Search MENU Toggle navigation Home Page Search ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions otulipenia otulipenia Enable Javascript to ...

  9. 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, ...

  10. 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 ...

  11. About Genetic Counselors

    MedlinePlus

    ... While most genetic counseling is provided in-person, access to genetic counselors is expanding, and many now provide consultation services by telephone, videoconferencing, and the internet, or offer education and support in group settings. ...

  12. Software For Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Wang, Lui; Bayer, Steve E.

    1992-01-01

    SPLICER computer program is genetic-algorithm software tool used to solve search and optimization problems. Provides underlying framework and structure for building genetic-algorithm application program. Written in Think C.

  13. 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

  14. Genetics in psychiatry.

    PubMed

    Umesh, Shreekantiah; Nizamie, Shamshul Haque

    2014-04-01

    Today, psychiatrists are focusing on genetics aspects of various psychiatric disorders not only for a future classification of psychiatric disorders but also a notion that genetics would aid in the development of new medications to treat these disabling illnesses. This review therefore emphasizes on the basics of genetics in psychiatry as well as focuses on the emerging picture of genetics in psychiatry and their future implications.

  15. Genetics in psychiatry

    PubMed Central

    Umesh, Shreekantiah; Nizamie, Shamshul Haque

    2014-01-01

    Today, psychiatrists are focusing on genetics aspects of various psychiatric disorders not only for a future classification of psychiatric disorders but also a notion that genetics would aid in the development of new medications to treat these disabling illnesses. This review therefore emphasizes on the basics of genetics in psychiatry as well as focuses on the emerging picture of genetics in psychiatry and their future implications. PMID:25400339

  16. Introductory molecular genetics

    SciTech Connect

    Edwards-Moulds, J.

    1986-01-01

    This book begins with an overview of the current principles of genetics and molecular genetics. Over this foundation, it adds detailed and specialized information: a description of the translation, transcription, expression and regulation of DNA and RNA; a description of the manipulation of genetic material via promoters, enhancers, and gene splicing; and a description of cloning techniques, especially those for blood group genes. The last chapter looks to the impact of molecular genetics on transfusion medicine.

  17. Genetics of psoriasis.

    PubMed

    Mahil, Satveer K; Capon, Francesca; Barker, Jonathan N

    2015-01-01

    Psoriasis is a common and debilitating immune-mediated skin disease with a complex genetic basis. Genetic studies have provided critical insights into the pathogenesis of disease. This article focuses on the results of genetic association studies, which provide evidence that psoriasis susceptibility genes are involved in innate and adaptive immunity and skin barrier functions. The potential for disease stratification and the development of more effective treatments with fewer side effects using genetic data are highlighted.

  18. 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, doing…

  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. 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, doing…

  1. 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…

  2. 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

  3. 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. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Massively Parallel Genetics.

    PubMed

    Shendure, Jay; Fields, Stanley

    2016-06-01

    Human genetics has historically depended on the identification of individuals whose natural genetic variation underlies an observable trait or disease risk. Here we argue that new technologies now augment this historical approach by allowing the use of massively parallel assays in model systems to measure the functional effects of genetic variation in many human genes. These studies will help establish the disease risk of both observed and potential genetic variants and to overcome the problem of "variants of uncertain significance." Copyright © 2016 by the Genetics Society of America.

  5. 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 National Society of Genetic Counselors ...

  6. Genetics Home Reference: centronuclear myopathy

    MedlinePlus

    ... genetic conditions treated or managed? What is genetic testing? How can I find a genetics professional in my area? ... Health Topic: Muscle Disorders Genetic and Rare Diseases Information Center (1 ...

  7. 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.

  8. Genetic interest assessment

    NASA Astrophysics Data System (ADS)

    Doughney, Erin

    Genetics is becoming increasingly integrated into peoples' lives. Different measures have been taken to try and better genetics education. This thesis examined undergraduate students at the University of North Texas not majoring in the life sciences interest in genetic concepts through the means of a Likert style survey. ANOVA analysis showed there was variation amongst the interest level in different genetic concepts. In addition age and lecture were also analyzed as contributing factors to students' interest. Both age and lecture were evaluated to see if they contributed to the interest of students in genetic concepts and neither showed statistical significance. The Genetic Interest Assessment (GIA) serves to help mediate the gap between genetic curriculum and students' interest.

  9. Evolutionary behavioral genetics.

    PubMed

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

    2015-04-01

    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.

  10. Rewriting the Genetic Code.

    PubMed

    Mukai, Takahito; Lajoie, Marc J; Englert, Markus; Söll, Dieter

    2017-09-08

    The genetic code-the language used by cells to translate their genomes into proteins that perform many cellular functions-is highly conserved throughout natural life. Rewriting the genetic code could lead to new biological functions such as expanding protein chemistries with noncanonical amino acids (ncAAs) and genetically isolating synthetic organisms from natural organisms and viruses. It has long been possible to transiently produce proteins bearing ncAAs, but stabilizing an expanded genetic code for sustained function in vivo requires an integrated approach: creating recoded genomes and introducing new translation machinery that function together without compromising viability or clashing with endogenous pathways. In this review, we discuss design considerations and technologies for expanding the genetic code. The knowledge obtained by rewriting the genetic code will deepen our understanding of how genomes are designed and how the canonical genetic code evolved.

  11. [Genetic diagnostics for cardiomyopathies].

    PubMed

    Czepluch, Frauke; Wollnik, Bernd; Hasenfuß, Gerd

    2017-05-01

    Cardiomyopathies often have a genetic etiology. New genetic diagnostic strategies based on next generation sequencing (NGS)-approaches will continuously increase our knowledge about the genetic basis of cardiomyopathies within the following years. Diagnostics and therapy of rare, genetically-induced cardiac diseases increasingly require special cardiac and genetic knowledge. Interestingly, mutations in the same gene or even identical gene mutations can be associated with different cardiomyopathy phenotypes and can exhibit incomplete penetrance or variable expressivity. In the future, the correct interpretation and classification of novel gene variants identified in patients with inherited cardiomyopathy forms will represent a great challenge. Genetic counselling and - if appropriate - subsequent genetic testing for cardiomyopathy patients and their asymptomatic relatives is essential for an early diagnosis of the disease, a prognostic evaluation and possibly for the start of preventive or therapeutic measures. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Genetic selection strategies--population genetics.

    PubMed

    Siegel, P B; Dunnington, E A

    1997-08-01

    This paper provides an overview of the association between population genetics and selection strategies in poultry. Relationships between artificial and natural selection and among causes contributing to limits to artificial selection are discussed. Homeostasis and resource allocations at the individual and at the population level are reviewed. Examples from poultry demonstrate where human intervention has circumvented biological limits. Lastly, this paper considers the role of population genetics in future breeding strategies for poultry.

  13. Genetics: advances in genetic testing for deafness

    PubMed Central

    Shearer, A. Eliot; Smith, Richard J.H.

    2013-01-01

    Purpose of review To provide an update on recently discovered human deafness genes and to describe advances in comprehensive genetic testing platforms for deafness, both of which have been enabled by new massively parallel sequencing technologies. Recent findings Over the review period, three syndromic and six nonsyndromic deafness genes have been discovered, bringing the total number of nonsyndromic deafness genes to 64. Four studies have shown the utility of massively parallel sequencing for comprehensive genetic testing for deafness. Three of these platforms have been released on a clinical or commercial basis. Summary Deafness is the most common sensory deficit in humans. Genetic diagnosis has traditionally been difficult due to extreme genetic heterogeneity and a lack of phenotypic variability. For these reasons, comprehensive genetic screening platforms have been developed with the use of massively parallel sequencing. These technologies are also accelerating the pace of gene discovery for deafness. Because genetic diagnosis is the basis for molecular therapies, these advances lay the foundation for the clinical care of deaf and hard-of-hearing persons in the future. PMID:23042251

  14. 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.

  15. [China genetic counseling network (CGCN): a website on genetic counseling and genetic education].

    PubMed

    He, Min; Li, Wei

    2007-03-01

    In April 2005, with the voluntary involvement of more than 50 worldwide genetic counselors or medical geneticists, we developed a website for online genetic counseling and genetic education on common genetic disease throughout China (URL: http://www.gcnet.org.cn). This website is offering professional online genetic counseling, as well as providing information about common genetic diseases which is a resource for genetic counselors and online genetic counselees. Online genetic counseling is an alternative method to the widely accepted face-to-face counseling. The data warehouse of China Genetic Counseling Network (CGCN) will be a unique supplement to current status of Clinical Genetics and healthcare system in China.

  16. Molecular Population Genetics.

    PubMed

    Casillas, Sònia; Barbadilla, Antonio

    2017-03-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. Copyright © 2017 Casillas and Barbadilla.

  17. Molecular Population Genetics

    PubMed Central

    Casillas, Sònia; Barbadilla, Antonio

    2017-01-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. PMID:28270526

  18. 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

  19. 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.

  20. Goals of genetic counseling.

    PubMed

    Biesecker, B B

    2001-11-01

    The goals of genetic counseling have differed over the past three decades. Two schools of thought are prominent in reviewing past literature. One upholds the goal of preventing birth defects and genetic disorders while the other promotes a goal of improved psychological well-being in client adaptation to a genetic condition or risk. Both types of goals emphasize that clients should make their own reproductive decisions; however, the former relies on clients making decisions that will reduce the impact of genetic disorders. The differences in the types of goals may be due to the training and orientation of genetics health care providers, socio-cultural views, or priorities of health care settings. Regardless, there are ample reasons to dismiss the prevention of birth defects as a goal. This mini-review recommends use of genetic counseling sub-specialties as a framework for considering different client needs and thus different counseling goals and specific aims in the reproductive, pediatric/adult, and common disease settings. Given the extent of new genetic information, technologies, and the need to evaluate genetic counseling practice, genetics health care providers should work toward arriving at consensus on the goals of genetic counseling, and in doing so, the needs of clients should be considered.

  1. 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

  2. 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.

  3. Genetic Pathways to Insomnia

    PubMed Central

    Lind, Mackenzie J.; Gehrman, Philip R.

    2016-01-01

    This review summarizes current research on the genetics of insomnia, as genetic contributions are thought to be important for insomnia etiology. We begin by providing an overview of genetic methods (both quantitative and measured gene), followed by a discussion of the insomnia genetics literature with regard to each of the following common methodologies: twin and family studies, candidate gene studies, and genome-wide association studies (GWAS). Next, we summarize the most recent gene identification efforts (primarily GWAS results) and propose several potential mechanisms through which identified genes may contribute to the disorder. Finally, we discuss new genetic approaches and how these may prove useful for insomnia, proposing an agenda for future insomnia genetics research. PMID:27999387

  4. Landscape genetics of plants.

    PubMed

    Holderegger, Rolf; Buehler, Dominique; Gugerli, Felix; Manel, Stéphanie

    2010-12-01

    Landscape genetics is the amalgamation of landscape ecology and population genetics to help with understanding microevolutionary processes such as gene flow and adaptation. In this review, we examine why landscape genetics of plants lags behind that of animals, both in number of studies and consideration of landscape elements. The classical landscape distance/resistance approach to study gene flow is challenging in plants, whereas boundary detection and the assessment of contemporary gene flow are more feasible. By contrast, the new field of landscape genetics of adaptive genetic variation, establishing the relationship between adaptive genomic regions and environmental factors in natural populations, is prominent in plant studies. Landscape genetics is ideally suited to study processes such as migration and adaptation under global change.

  5. Genetic screening for deafness.

    PubMed

    Smith, Richard J H; Hone, Stephen

    2003-04-01

    Genetic testing for deafness has become a reality. It has changed the paradigm for evaluating deaf and hard-of-hearing persons and will be used by physicians for diagnostic purposes and as a basis for treatment and management options. Although mutation screening is currently available for only a limited number of genes, in these specific instances, diagnosis, carrier detection, and reproductive risk counseling can be provided. In the coming years there will be an expansion of the role of genetic testing and counseling will not be limited to reproductive issues. Treatment and management decisions will be made based on specific genetic diagnoses. Although genetic testing may be a confusing service for the practicing otolaryngologist, it is an important part of medical care. New discoveries and technologies will expand and increase the complexity of genetic testing options and it will become the responsibility of otolaryngologists to familiarize themselves with current discoveries and accepted protocols for genetic testing.

  6. PCR in forensic genetics.

    PubMed

    Morling, Niels

    2009-04-01

    Since the introduction in the mid-1980s of analyses of minisatellites for DNA analyses, a revolution has taken place in forensic genetics. The subsequent invention of the PCR made it possible to develop forensic genetics tools that allow both very informative routine investigations and still more and more advanced, special investigations in cases concerning crime, paternity, relationship, disaster victim identification etc. The present review gives an update on the use of DNA investigations in forensic genetics.

  7. 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

  8. Genetic enhancements and expectations.

    PubMed

    Sorensen, K

    2009-07-01

    Some argue that genetic enhancements and environmental enhancements are not importantly different: environmental enhancements such as private schools and chess lessons are simply the old-school way to have a designer baby. I argue that there is an important distinction between the two practices--a distinction that makes state restrictions on genetic enhancements more justifiable than state restrictions on environmental enhancements. The difference is that parents have no settled expectations about genetic enhancements.

  9. Credible genetic associations?

    PubMed Central

    Munafò, Marcus R

    2010-01-01

    The proliferation in genetic association studies, and the recurring failure of initially promising findings to robustly replicate, demonstrates the need for stringent standards to ensure the identification of credible associations. The Human Genome Epidemiology Network has recently published intermin guideliness on evidential criteria for genetic association studies. These are reviewed, and their value and importance discussed, as well as the impact these guidelines will have on the conduct of genetic association studies. PMID:21537450

  10. Genetics Home Reference: aniridia

    MedlinePlus

    ... Genetic Testing Registry: Congenital aniridia Other Diagnosis and Management Resources (1 link) GeneReview: Aniridia General Information from MedlinePlus (5 links) Diagnostic Tests Drug Therapy ...

  11. Genetic sperm defects.

    PubMed

    Chenoweth, Peter J

    2005-08-01

    Genetic sperm defects are specific sperm defects, which have been shown to have a genetic mode of transmission. Such genetic linkage, either direct or indirect, has been associated with a number of sperm defects in different species, with this number increasing with improved diagnostic capabilities. A number of sperm defects, which have proven or suspected genetic modes of transmission are discussed herein, with particular emphasis on cattle. These include: 1. Acrosome defects (knobbed, ruffled and incomplete); 2. Head defects (abnormal condensation, decapitated, round head, rolled head, nuclear crest); 3. Midpiece abnormalities ("Dag" defect, "corkscrew" defect, "pseudo-droplet" defect); 4. Tail defects ("tail stump" defect, primary ciliary dyskinesia).

  12. 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.

  13. The Genetics of Keratoconus

    PubMed Central

    Nowak, Dorota M.; Gajecka, Marzena

    2011-01-01

    Keratoconus (KTCN) is non-inflammatory thinning and anterior protrusion of the cornea that results in steepening and distortion of the cornea, altered refractive error, and decreased vision. Keratoconus is a complex condition of multifactorial etiology. Both genetic and environmental factors are associated with KTCN. Evidence of genetic etiology includes familial inheritance, discordance between dizygotic twins, and association with other known genetic disorders. Several loci responsible for a familial form of KTCN have been mapped; however, no mutations in any genes have been identified for any of these loci. This article focuses on the genetic aspects. In addition, bioinformatics methods applied in KTCN gene identification process are discussed. PMID:21572727

  14. Preimplantation genetic screening.

    PubMed

    Harper, Joyce C

    2017-01-01

    Preimplantation genetic diagnosis was first successfully performed in 1989 as an alternative to prenatal diagnosis for couples at risk of transmitting a genetic or chromosomal abnormality, such as cystic fibrosis, to their child. From embryos generated in vitro, biopsied cells are genetically tested. From the mid-1990s, this technology has been employed as an embryo selection tool for patients undergoing in vitro fertilisation, screening as many chromosomes as possible, in the hope that selecting chromosomally normal embryos will lead to higher implantation and decreased miscarriage rates. This procedure, preimplantation genetic screening, was initially performed using fluorescent in situ hybridisation, but 11 randomised controlled trials of screening using this technique showed no improvement in in vitro fertilisation delivery rates. Progress in genetic testing has led to the introduction of array comparative genomic hybridisation, quantitative polymerase chain reaction, and next generation sequencing for preimplantation genetic screening, and three small randomised controlled trials of preimplantation genetic screening using these new techniques indicate a modest benefit. Other trials are still in progress but, regardless of their results, preimplantation genetic screening is now being offered globally. In the near future, it is likely that sequencing will be used to screen the full genetic code of the embryo.

  15. Genetics of nonsyndromic obesity.

    PubMed

    Lee, Yung Seng

    2013-12-01

    Common obesity is widely regarded as a complex, multifactorial trait influenced by the 'obesogenic' environment, sedentary behavior, and genetic susceptibility contributed by common and rare genetic variants. This review describes the recent advances in understanding the role of genetics in obesity. New susceptibility loci and genetic variants are being uncovered, but the collective effect is relatively small and could not explain most of the BMI heritability. Yet-to-be identified common and rare variants, epistasis, and heritable epigenetic changes may account for part of the 'missing heritability'. Evidence is emerging about the role of epigenetics in determining obesity susceptibility, mediating developmental plasticity, which confers obesity risk from early life experiences. Genetic prediction scores derived from selected genetic variants, and also differential DNA methylation levels and methylation scores, have been shown to correlate with measures of obesity and response to weight loss intervention. Genetic variants, which confer susceptibility to obesity-related morbidities like nonalcoholic fatty liver disease, were also discovered recently. We can expect discovery of more rare genetic variants with the advent of whole exome and genome sequencing, and also greater understanding of epigenetic mechanisms by which environment influences genetic expression and which mediate the gene-environment interaction.

  16. Going Forward with Genetics

    PubMed Central

    Moresco, Eva Marie Y.; Li, Xiaohong; Beutler, Bruce

    2014-01-01

    Forward genetic analysis is an unbiased approach for identifying genes essential to defined biological phenomena. When applied to mice, it is one of the most powerful methods to facilitate understanding of the genetic basis of human biology and disease. The speed at which disease-causing mutations can be identified in mutagenized mice has been markedly increased by recent advances in DNA sequencing technology. Creating and analyzing mutant phenotypes may therefore become rate-limiting in forward genetic experimentation. We review the forward genetic approach and its future in the context of recent technological advances, in particular massively parallel DNA sequencing, induced pluripotent stem cells, and haploid embryonic stem cells. PMID:23608223

  17. 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

  18. Systems Genetics of Alcoholism

    PubMed Central

    Sloan, Chantel D.; Sayarath, Vicki; Moore, Jason H.

    2008-01-01

    Alcoholism is a common disease resulting from the complex interaction of genetic, social, and environmental factors. Interest in the high heritability of alcoholism has resulted in many studies of how single genes, as well as an individual’s entire genetic content (i.e., genome) and the proteins expressed by the genome, influence alcoholism risk. The use of large-scale methods to identify and characterize genetic material (i.e., high-throughput technologies) for data gathering and analysis recently has made it possible to investigate the complexity of the genetic architecture of susceptibility to common diseases such as alcoholism on a systems level. Systems genetics is the study of all genetic variations, their interactions with each other (i.e., epistasis), their interactions with the environment (i.e., plastic reaction norms), their relationship with interindividual variation in traits that are influenced by many genes and contribute to disease susceptibility (i.e., intermediate quantitative traits or endophenotypes1) defined at different levels of hierarchical biochemical and physiological systems, and their relationship with health and disease. The goal of systems genetics is to provide an understanding of the complex relationship between the genome and disease by investigating intermediate biological processes. After investigating main effects, the first step in a systems genetics approach, as described here, is to search for gene–gene (i.e., epistatic) reactions. PMID:23584748

  19. Chapter 14: Genetic diversity

    Treesearch

    C. I. Millar

    1999-01-01

    Genetic diversity rarely makes headline news. Whereas species extinctions, loss of old-growth forests, and catastrophic forest fires are readily grasped public issues, genetic diversity is often perceived as arcane and academic. Yet genes are the fundamental unit of biodiversity, the raw material for evolution, and the ultimate source of all variation among plants and...

  20. 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…

  1. 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

  2. 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…

  3. 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…

  4. 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.

  5. Genetic selection and preservation of genetic diversity

    USDA-ARS?s Scientific Manuscript database

    For 100’s 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 risen and fallen out of favor o...

  6. Cryptic Genetic Variation in Evolutionary Developmental Genetics.

    PubMed

    Paaby, Annalise B; Gibson, Greg

    2016-06-13

    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.

  7. 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

  8. Genetic Counseling for Hearing Loss.

    ERIC Educational Resources Information Center

    Arnos, Kathleen S.

    1997-01-01

    This article addresses epidemiologic and demographic characteristics of hereditary hearing loss and genetic evaluation and counseling. It discusses who should have genetic counseling, the genetic counseling process, and effects of genetics technology on the genetic counseling process. A case study of a 2-year-old with severe sensorineural hearing…

  9. 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

  10. GENETIC COUNSELLING IN MELANOMA

    PubMed Central

    Badenas, Celia; Aguilera, Paula; Puig-Butillé, Joan A.; Carrera, Cristina; Malvehy, Josep; Puig, Susana

    2012-01-01

    Summary Genetic counselling may be offered to families with melanoma and to individuals with multiple melanomas to better understand the genetic susceptibility of the disease, the influence of environmental factors, the inheritance of the risk and behaviour that decreases the risk of dying from melanoma including specific dermatological follow-up such as total body photography and digital dermoscopy. Genetic testing may be offered to those individuals with more than a 10% chance of being a carrier of a mutation. This risk varies according to the incidence of melanoma in the country and sun behaviour. In countries with a low-medium incidence of melanoma, genetic testing should be offered to families with two cases of melanoma or an individual with two primary melanomas. In countries with a high incidence, families with three cases of melanoma, with two melanomas and one pancreatic adenocarcinoma, or patients with three primary melanomas may benefit from genetic testing. PMID:23046018

  11. Genetics of stroke

    PubMed Central

    Guo, Jin-min; Liu, Ai-jun; Su, Ding-feng

    2010-01-01

    Stroke is the second most common cause of death and the most common cause of disability in developed countries. Stroke is a multi-factorial disease caused by a combination of environmental and genetic factors. Numerous epidemiologic studies have documented a significant genetic component in the occurrence of strokes. Genes encoding products involved in lipid metabolism, thrombosis, and inflammation are believed to be potential genetic factors for stroke. Although a large group of candidate genes have been studied, most of the epidemiological results are conflicting. Studies of stroke as a monogenic disease have made huge progress, and animal models serve as an indispensable tool to dissect the complex genetics of stroke. In the present review, we provide insight into the role of in vivo stroke models for the study of stroke genetics. PMID:20729874

  12. 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)

  13. 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)

  14. Should patients with ocular genetic disorders have genetic testing?

    PubMed

    Zanolli, Mario T; Khetan, Vikas; Dotan, Gad; Pizzi, Laura; Levin, Alex V

    2014-09-01

    To discuss the risks, benefits and value of genetic testing for ocular genetic disease. Testing for ocular genetics diseases is becoming more available and successful gene therapy is being reported. Clinicians must prepare for this trend by considering diagnostic genetic testing for their patients. As advances continually occur in genetic testing for ocular genetic disorders, clinicians must develop an understanding of the potential risks and benefits for their patients.

  15. 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 ...

  16. Genetics Home Reference: anonychia congenita

    MedlinePlus

    ... of cells to one another (adhesion), cell movement (migration), and many other cellular activities. During early development, ... More about Inheriting Genetic Conditions Diagnosis & Management Genetic Testing (1 link) Genetic Testing Registry: Anonychia General Information ...

  17. Genetics & the Quality of Life.

    ERIC Educational Resources Information Center

    McInerney, Joseph D.

    1989-01-01

    Describes the contribution made to the quality of human life by the study of genetics. Presents a description of the current status of genetics education. Suggests changes in genetics education necessary to keep up with new developments. (39 references) (CW)

  18. 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.

  19. Genetics and sports.

    PubMed

    Lippi, Giuseppe; Longo, Umile Giuseppe; Maffulli, Nicola

    2010-01-01

    The limit of each individual to perform a given type of exercise depends on the nature of the task, and is influenced by a variety of factors, including psychology, environment and genetic make up. Genetics provide useful insights, as sport performances can be ultimately defined as a polygenic trait. We searched PubMed using the terms 'sports' and 'genetics' over the period 1990 to present. The physical performance phenotypes for which a genetic basis can be suspected include endurance capacity, muscle performance, physiological attitude to train and ability of tendons and ligaments to withstand injury. Genetic testing in sport would permit to identify individuals with optimal physiology and morphology, and also those with a greater capacity to respond/adapt to training and a lesser chance of suffering from injuries. Ethical and practical caveats should be clearly emphasized. The translation of an advantageous genotype into a champion's phenotype is still influenced by environmental, psychological and sociological factors. The current scientific evidence on the relationship between genetics and sports look promising. There is a need for additional studies to determine whether genome-wide genotyping arrays would be really useful and cost-effective. Since exercise training regulates the expression of genes encoding various enzymes in muscle and other tissues, genetic research in sports will help clarify several aspects of human biology and physiology, such as RNA and protein level regulation under specific circumstances.

  20. Genetics and Intervention Research

    PubMed Central

    Plomin, Robert; Haworth, Claire M.A.

    2014-01-01

    As part of this special section on genetics and behavioral intervention, we discuss the papers by McGue et al. and by Davey Smith. In the second half of our paper, we consider the integration of genetics and intervention research more broadly. The two papers describe ways to use genetic controls to infer causation from correlational (‘observational’) data without intervention. McGue et al. discuss the use of twins discordant for exposure, which is a variant of the co-twin control method. This method can show that the link between an exposure and outcome is not entirely mediated genetically. Davey Smith discusses a method called Mendelian randomization that uses DNA to draw causal inferences without the need for experimental intervention. Despite the possibilities for using genetic controls to infer causation from correlational data in order to attenuate the need for intervention studies, we are most excited about the opportunities for integrating genetics and intervention research, especially as new DNA technologies make it possible to incorporate genetics in any intervention research. PMID:25419226

  1. On Derivations Of Genetic Algebras

    NASA Astrophysics Data System (ADS)

    Mukhamedov, Farrukh; Qaralleh, Izzat

    2014-11-01

    A genetic algebra is a (possibly non-associative) algebra used to model inheritance in genetics. In application of genetics this algebra often has a basis corresponding to genetically different gametes, and the structure constant of the algebra encode the probabilities of producing offspring of various types. In this paper, we find the connection between the genetic algebras and evolution algebras. Moreover, we prove the existence of nontrivial derivations of genetic algebras in dimension two.

  2. 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.

  3. Statistics for Learning Genetics

    NASA Astrophysics Data System (ADS)

    Charles, Abigail Sheena

    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, doing statistically-based genetics problems. This issue is at the emerging edge of modern college-level genetics instruction, and this study attempts to identify key theoretical components for creating a specialized biological statistics curriculum. The goal of this curriculum will be to prepare biology students with the skills for assimilating quantitatively-based genetic processes, increasingly at the forefront of modern genetics. To fulfill this, two college level classes at two universities were surveyed. One university was located in the northeastern US and the other in the West Indies. There was a sample size of 42 students and a supplementary interview was administered to a select 9 students. Interviews were also administered to professors in the field in order to gain insight into the teaching of statistics in genetics. Key findings indicated that students had very little to no background in statistics (55%). Although students did perform well on exams with 60% of the population receiving an A or B grade, 77% of them did not offer good explanations on a probability question associated with the normal distribution provided in the survey. The scope and presentation of the applicable statistics/mathematics in some of the most used textbooks in genetics teaching, as well as genetics syllabi used by instructors do not help the issue. It was found that the text books, often times, either did not give effective explanations for students, or completely left out certain topics. The omission of certain statistical/mathematical oriented topics was seen to be also true with the genetics syllabi reviewed for this study. Nonetheless

  4. 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.

  5. [Genetic risk and discrimination].

    PubMed

    Vidal Gallardo, Mercedes

    2010-01-01

    The continuous advances in our society in the last decades have allowed us to get to know the personal genetic data. Although this discovery has important benefits, it also causes a great paradox, since the genetic information can be an element of social stigma, and its inappropriate use can damage the fundamental rights. It is obvious that there are cases in which the genetic risk, that is, the predisposition of a person to suffer some illnesses, can be a discriminatory element, especially in the contractual field.

  6. Genetics and antisocial behavior.

    PubMed

    Joseph, Jay

    2003-01-01

    This commentary article reviews a recent meta-analysis of genetic influences on antisocial behavior by Rhee and Waldman (2002). The authors combined the results of 51 twin and adoption studies and concluded that antisocial behavior has an important genetic component. However, twin and adoption studies contain several methodological flaws and are subject to the confounding influence of environmental factors. Therefore, Rhee and Waldman's conclusions in favor of genetic influences are not supported by the evidence. Two additional topics are Rhee and Waldman's incorrect description of the heritability concept and their failure to discuss several German criminal twin studies published during the Nazi era.

  7. Genetics of dispersal.

    PubMed

    Saastamoinen, Marjo; Bocedi, Greta; Cote, Julien; Legrand, Delphine; Guillaume, Frédéric; Wheat, Christopher W; Fronhofer, Emanuel A; Garcia, Cristina; Henry, Roslyn; Husby, Arild; Baguette, Michel; Bonte, Dries; Coulon, Aurélie; Kokko, Hanna; Matthysen, Erik; Niitepõld, Kristjan; Nonaka, Etsuko; Stevens, Virginie M; Travis, Justin M J; Donohue, Kathleen; Bullock, James M; Del Mar Delgado, Maria

    2017-08-03

    Dispersal is a process of central importance for the ecological and evolutionary dynamics of populations and communities, because of its diverse consequences for gene flow and demography. It is subject to evolutionary change, which begs the question, what is the genetic basis of this potentially complex trait? To address this question, we (i) review the empirical literature on the genetic basis of dispersal, (ii) explore how theoretical investigations of the evolution of dispersal have represented the genetics of dispersal, and (iii) discuss how the genetic basis of dispersal influences theoretical predictions of the evolution of dispersal and potential consequences. Dispersal has a detectable genetic basis in many organisms, from bacteria to plants and animals. Generally, there is evidence for significant genetic variation for dispersal or dispersal-related phenotypes or evidence for the micro-evolution of dispersal in natural populations. Dispersal is typically the outcome of several interacting traits, and this complexity is reflected in its genetic architecture: while some genes of moderate to large effect can influence certain aspects of dispersal, dispersal traits are typically polygenic. Correlations among dispersal traits as well as between dispersal traits and other traits under selection are common, and the genetic basis of dispersal can be highly environment-dependent. By contrast, models have historically considered a highly simplified genetic architecture of dispersal. It is only recently that models have started to consider multiple loci influencing dispersal, as well as non-additive effects such as dominance and epistasis, showing that the genetic basis of dispersal can influence evolutionary rates and outcomes, especially under non-equilibrium conditions. For example, the number of loci controlling dispersal can influence projected rates of dispersal evolution during range shifts and corresponding demographic impacts. Incorporating more realism in

  8. 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.

  9. Genetic engineering of mammals.

    PubMed

    Wells, Kevin D

    2016-01-01

    Historically, genetic engineering for mammalian reproductive questions has been accomplished primarily in the mouse. However, all the genetic manipulations that can be done in the mouse can now be accomplished in most domesticated mammals. Random integration of transgenes, homologous recombination and gene editing are now routine for several mammalian species. For livestock, queries related to fertility can be asked directly for the species in question, without a need for a mouse model. For human clinical concerns, the most appropriate model should be selected based on physiology, anatomy, or even size. The mouse will continue to be a useful genetically engineered model. However, other species are now amenable to the full range of genetic manipulations and should be considered as possible models for human conditions when appropriate.

  10. 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 ...

  11. 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 ...

  12. 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)

  13. Genetics and epilepsy

    PubMed Central

    Steinlein, Ortrud K.

    2008-01-01

    The term “epilepsy” describes a heterogeneous group of disorders, most of them caused by interactions between several or even many genes and environmental factors. Much rarer are the genetic epilepsies that are due to single-gene mutations or defined structural chromosomal aberrations, such as microdeletions. The discovery of several of the genes underlying these rare genetic epilepsies has already considerably contributed to our understanding of the basic mechanisms epileptogenesis. The progress made in the last 15 years in the genetics of epilepsy is providing new possibilities for diagnosis and therapy. Here, different genetic epilepsies are reviewed as examples, to demonstrate the various pathways that can lead from genes to seizures. PMID:18472482

  14. Genetics Home Reference: globozoospermia

    MedlinePlus

    ... Encyclopedia: Semen Analysis MedlinePlus Health Topic: Assisted Reproductive Technology General Information from MedlinePlus (5 links) Diagnostic Tests Drug Therapy Genetic Counseling Palliative Care Surgery and ...

  15. Genetics Home Reference: macrozoospermia

    MedlinePlus

    ... Encyclopedia: Semen Analysis MedlinePlus Health Topic: Assisted Reproductive Technology General Information from MedlinePlus (5 links) Diagnostic Tests Drug Therapy Genetic Counseling Palliative Care Surgery and ...

  16. Genetics Home Reference: sialuria

    MedlinePlus

    ... in my area? Other Names for This Condition French type sialuria Sialuria, French type Related Information How are genetic conditions and ... and Rare Diseases Information Center (1 link) Sialuria, French type Educational Resources (5 links) Cincinnati Children's Hospital ...

  17. 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.

  18. Genetics and identity.

    PubMed

    Nordgren, Anders

    2008-01-01

    For the last 20 years the concepts of identity and identification have been subject to much interest in the humanities and social sciences. However, the implications of genetics for identity and identification have been largely neglected. In this paper, I distinguish various conceptions of identity (as continuity over time, as basic kind of being, as unique set of properties, and as social role) and identification (as subjective experience of identity in various senses and as social ascription of identity in various senses), and investigate systematically genetic perspectives on each of these conceptions. I stress the importance of taking the genetic perspectives seriously but also their limitations. In particular, I pinpoint conceptual problems that arise when a genetic approach to identity is adopted.

  19. Genetics and delusional disorder.

    PubMed

    Cardno, Alastair G; McGuffin, Peter

    2006-01-01

    This article gives an overview of genetic research approaches and their application to delusional disorder. Most studies have been based on small samples and have had other methodological limitations, so it is not clear whether there is a genetic contribution to the aetiology of delusional disorder. It is unlikely that delusional disorder is strongly related genetically to affective disorder or schizophrenia, but more subtle relationships cannot be ruled out. The rarity of multiply affected families prohibits linkage studies and, to date, molecular genetic investigations have been mainly limited to small association studies of dopamine receptor polymorphisms. A range of considerably larger, epidemiologically rigorous studies is required, but the uncommonness and other features of the disorder put strong limitations on the prospects for ascertaining adequate samples.

  20. 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 ...

  1. 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 ( ...

  2. 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 ...

  3. 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) ...

  4. 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

  5. Genetics of anxiety disorders.

    PubMed

    Arnold, Paul D; Zai, Gwyneth; Richter, Margaret A

    2004-08-01

    There is considerable evidence that genetic determinants play a major role in the etiology of anxiety. Investigations into susceptibility genes for anxiety are well underway, particularly for panic disorder and obsessive-compulsive disorder and more broadly defined anxiety-related traits, such as neuroticism and harm avoidance. This review will discuss some of the core issues related to diagnosis and molecular genetic methodology, followed by a review of recent molecular genetic findings for anxiety. The authors will attempt to highlight the numerous convergent and exciting findings. Given the rapid acceleration in knowledge of the human genome, a more definitive understanding of the genetic roots of these complex conditions may be anticipated in the relatively near future.

  6. 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)

  7. Genetics of Alzheimer's Disease

    PubMed Central

    Ridge, Perry G.; Ebbert, Mark T. W.; Kauwe, John S. K.

    2013-01-01

    Alzheimer's disease is the most common form of dementia and is the only top 10 cause of death in the United States that lacks disease-altering treatments. It is a complex disorder with environmental and genetic components. There are two major types of Alzheimer's disease, early onset and the more common late onset. The genetics of early-onset Alzheimer's disease are largely understood with variants in three different genes leading to disease. In contrast, while several common alleles associated with late-onset Alzheimer's disease, including APOE, have been identified using 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 Alzheimer's disease. PMID:23984328

  8. Genetically engineering milk.

    PubMed

    Whitelaw, C Bruce A; Joshi, Akshay; Kumar, Satish; Lillico, Simon G; Proudfoot, Chris

    2016-02-01

    It has been thirty years since the first genetically engineered animal with altered milk composition was reported. During the intervening years, the world population has increased from 5bn to 7bn people. An increasing demand for protein in the human diet has followed this population expansion, putting huge stress on the food supply chain. Many solutions to the grand challenge of food security for all have been proposed and are currently under investigation and study. Amongst these, genetics still has an important role to play, aiming to continually enable the selection of livestock with enhanced traits. Part of the geneticist's tool box is the technology of genetic engineering. In this Invited Review, we indicate that this technology has come a long way, we focus on the genetic engineering of dairy animals and we argue that the new strategies for precision breeding demand proper evaluation as to how they could contribute to the essential increases in agricultural productivity our society must achieve.

  9. 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.

  10. [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.

  11. 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.

  12. 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. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  13. 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

  14. [Genetics of congenital cardiopathies].

    PubMed

    Moreno García, M; Gómez Rodríguez, M J; Barreiro Miranda, E

    2000-07-01

    Congenital heart malformations are the most common of all birth defects, affecting 0.5-1% of all live births. Some of these malformations are due to genetic anomalies. Patterns of autosomal dominant, autosomal recessive and X-linked inheritance have been described. Mitochondrial inheritance and chromosomal anomalies can also be responsible for congenital heart malformations. Several genes for congenital heart defects have been identified. We review current knowledge on the genetic etiology of congenital heart disease.

  15. Christianity, health, and genetics.

    PubMed

    Smith, David H

    2009-02-15

    Health is an intrinsic value that Christians should respect, but it is not the highest value. Christians should be willing to jeopardize their own health for the health of others, and should repudiate any idea that genetic problems are the result of sin. Rather, sin leads us to make genetic problems harder to live with than they should be. (c) 2009 Wiley-Liss, Inc.

  16. 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.

  17. 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.

  18. 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.

  19. Population genetics and evolution

    SciTech Connect

    De Jong, G.

    1988-01-01

    This volume reevaluates the position of population genetics in evolutionary biology by using population genetics as the tool to study the role of development and adaptation in evolution. The emphasis is on the organismic process of selection, and on how the study of selection means connecting variation at the molecular, biochemical, and phenotypic levels of organization with the resulting variation in fitness. This book illustrates that the tendency to view single locus differences in isolation as the building blocks of evolution is disappearing.

  20. Human hemoglobin genetics

    SciTech Connect

    Honig, G.R.; Adams, J.G.

    1986-01-01

    This book contains the following 10 chapters: Introduction; The Human Hemoglobins; The Human Globin Genes; Hemoglobin Synthesis and Globin Gene Expression; The Globin Gene Mutations - A. Mechanisms and Classification; The Globin Gene Mutations - B. Their Phenotypes and Clinical Expression; The Genetics of the Human Globin Gene Loci: Formal Genetics and Gene Linkage; The Geographic Distribution of Globin Gene Variation; Labortory Identification, Screening, Education, and Counseling for Abnormal Hemoglobins and Thalassemias; and Approaches to the Treatment of the Hemoglobin Disorders.

  1. Genetic diseases in adults.

    PubMed

    Kolettis, Peter N

    2003-02-01

    Genetic diseases that do not primarily affect the genitourinary tract may have urologic manifestations. These urologic manifestations range from benign and malignant renal disease to infertility. Thus, the practicing urologist may be involved in the care of these patients and should have knowledge of these diseases. Continued improvements in the diagnosis and treatment of these genetic diseases will likely result in improved survival and will increase the number of patients who may develop urologic manifestations of these diseases.

  2. Genetics and preterm birth.

    PubMed

    Allen, Carolyn M; Founds, Sandra A

    2013-01-01

    Although the etiology of preterm birth is incompletely understood, phenotype classifications combined with recent technologies such as genome-wide association studies and next-generation sequencing could lead to discovering genotypes associated with preterm birth. Identifying genetic contributions will allow for genetic screening tests to predict or detect pregnancies with potential for preterm birth. In this article we discuss current knowledge regarding phenotype classifications, genotypes, and their associations with preterm birth.

  3. Genetics of ischaemic stroke.

    PubMed

    Sharma, Pankaj; Yadav, Sunaina; Meschia, James F

    2013-12-01

    Recent advances in genomics and statistical computation have allowed us to begin addressing the genetic basis of stroke at a molecular level. These advances are at the cusp of making important changes to clinical practice of some monogenic forms of stroke and, in the future, are likely to revolutionise the care provided to these patients. In this review we summarise the state of knowledge in ischaemic stroke genetics particularly in the context of how a practicing clinician can best use this knowledge.

  4. 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.

  5. Genetics of alcoholism.

    PubMed

    Schuckit, M A; Li, T K; Cloninger, C R; Deitrich, R A

    1985-12-01

    Great progress has been made by research on the contribution genetic factors make to a vulnerability toward alcoholism. Animal studies have demonstrated the importance of genetics in ethanol preference and levels of consumption, and human family, twin, and adoption research have revealed a 4-fold higher risk for offspring of alcoholics, even if they were adopted out at birth. The work presented in this symposium reviews the ongoing search for genetic trait markers of a vulnerability toward alcoholism. Dr. Li has used both animal and human research to demonstrate the possible importance of the genetic control of enzymes involved in ethanol metabolism and has worked to help develop an animal model of alcoholism. The possible importance of subgroups with different levels of predisposition toward alcoholism is emphasized by Dr. Cloninger. An overview of the studies of sons of alcoholics, given by Dr. Schuckit, reveals the potential importance of a decreased intensity of reaction to ethanol as part of a predisposition toward alcoholism and discusses the possible impact of some brain waves and ethanol metabolites to an alcoholism vulnerability. Dr. Deitrich reviews interrelationships between studies of animals and humans in the search for factors involved in a genetic vulnerability toward alcoholism. Taken together, these presentations underscore the importance of genetic factors in alcoholism, review animal and human research attempting to identify markers of a vulnerability, and reveal the high level of interaction between human and animal research.

  6. 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

  7. Early Alzheimer's disease genetics.

    PubMed

    Schellenberg, Gerard D

    2006-01-01

    The genetics community working on Alzheimer's disease and related dementias has made remarkable progress in the past 20 years. The cumulative efforts by multiple groups have lead to the identification of three autosomal dominant genes for early onset AD. These are the amyloid-beta protein precursor gene (APP), and the genes encoding presenilin1 and 2. The knowledge derived from this work has firmly established Abeta as a critical disease molecule and lead to candidate drugs currently in treatment trials. Work on a related disease, frontotemporal dementia with parkinsonism - chromosome 17 type has also added to our understanding of pathogenesis by revealing that tau, the protein component of neurofibrillary tangles, is also a critical molecule in neurodegeneration. Lessons learned that still influence work on human genetics include the need to recognize and deal with genetic heterogeneity, a feature common to many genetic disorders. Genetic heterogeneity, if recognized, can be source of information. Another critical lesson is that clinical, molecular, and statistical scientists need to work closely on disease projects to succeed in solving the complex problems of common genetic disorders.

  8. [Genetic mental retardation].

    PubMed

    Rodríguez-Revenga Bodi, L; Madrigal-Bajo, I; Milà-Racasens, M

    2006-10-10

    Mental retardation is a frequently occurring disorder with a major impact on the life of the affected person, the family and society, with an estimated incidence of 1-3% in developed countries. Among the etiologies that cause mental retardation it would appear that 30% have a genetic origin, 15% have an environmental origin, and the rest have an unknown origin. AIM. To report the genetic causes of mental retardation and the new molecular techniques used in order to reach a diagnosis. The identification of the causes of mental retardation is of great interest due to the consequences it has in the intervention, prognosis, estimation of risk of recurrence and its prevention. Causes of mental retardation are extremely heterogeneous. Genetic causes can be classified as chromosomal alterations (aneuploidies, subtelomeric rearrangements, microdeletion or microduplication syndrome), monogenic, metabolic, or multifactorial alterations. Thanks to the development of high-resolution new techniques -comparative genomic hybridization (CGH) arrays, and multiplex ligation probe amplification (MLPA)- now we are able to detect microdeletions and microduplication all over the genome, which might be related with mental retardation. The genetic causes of mental retardation are highly heterogeneous and complex. Nowadays and thanks to the new molecular techniques we are able to perform several studies, even though almost half of cases remain undiagnosed. In those undiagnosed cases with positive familial history a genetic counseling can be provided. However, in order to perform a prenatal or a preimplantational study a genetic diagnosis is required.

  9. Synchronization of genetic oscillators

    NASA Astrophysics Data System (ADS)

    Zhou, Tianshou; Zhang, Jiajun; Yuan, Zhanjiang; Chen, Luonan

    2008-09-01

    Synchronization of genetic or cellular oscillators is a central topic in understanding the rhythmicity of living organisms at both molecular and cellular levels. Here, we show how a collective rhythm across a population of genetic oscillators through synchronization-induced intercellular communication is achieved, and how an ensemble of independent genetic oscillators is synchronized by a common noisy signaling molecule. Our main purpose is to elucidate various synchronization mechanisms from the viewpoint of dynamics, by investigating the effects of various biologically plausible couplings, several kinds of noise, and external stimuli. To have a comprehensive understanding on the synchronization of genetic oscillators, we consider three classes of genetic oscillators: smooth oscillators (exhibiting sine-like oscillations), relaxation oscillators (displaying jump dynamics), and stochastic oscillators (noise-induced oscillation). For every class, we further study two cases: with intercellular communication (including phase-attractive and repulsive coupling) and without communication between cells. We find that an ensemble of smooth oscillators has different synchronization phenomena from those in the case of relaxation oscillators, where noise plays a different but key role in synchronization. To show differences in synchronization between them, we make comparisons in many aspects. We also show that a population of genetic stochastic oscillators have their own synchronization mechanisms. In addition, we present interesting phenomena, e.g., for relaxation-type stochastic oscillators coupled to a quorum-sensing mechanism, different noise intensities can induce different periodic motions (i.e., inhomogeneous limit cycles).

  10. Genetic testing in ALS

    PubMed Central

    McLaughlin, Russell L.; Heverin, Mark; Thorpe, Owen; Abrahams, Sharon; Al-Chalabi, Ammar; Hardiman, Orla

    2017-01-01

    Objective: To determine the degree of consensus among clinicians on the clinical use of genetic testing in amyotrophic lateral sclerosis (ALS) and the factors that determine decision-making. Methods: ALS researchers worldwide were invited to participate in a detailed online survey to determine their attitudes and practices relating to genetic testing. Results: Responses from 167 clinicians from 21 different countries were analyzed. The majority of respondents (73.3%) do not consider that there is a consensus definition of familial ALS (FALS). Fifty-seven percent consider a family history of frontotemporal dementia and 48.5% the presence of a known ALS genetic mutation as sufficient for a diagnosis of FALS. Most respondents (90.2%) offer genetic testing to patients they define as having FALS and 49.4% to patients with sporadic ALS. Four main genes (SOD1, C9orf72, TARDBP, and FUS) are commonly tested. A total of 55.2% of respondents would seek genetic testing if they had personally received a diagnosis of ALS. Forty-two percent never offer presymptomatic testing to family members of patients with FALS. Responses varied between ALS specialists and nonspecialists and based on the number of new patients seen per year. Conclusions: There is a lack of consensus among clinicians as to the definition of FALS. Substantial variation exists in attitude and practices related to genetic testing of patients and presymptomatic testing of their relatives across geographic regions and between experienced specialists in ALS and nonspecialists. PMID:28159885

  11. 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…

  12. Social Work and the Genetics Revolution: Genetic Services.

    ERIC Educational Resources Information Center

    Rauch, Julia B.

    1988-01-01

    Describes basic genetic concepts and genetic services provided by social workers which involve counseling clients with genetic concerns. Contends this adds to the requisites of social work practice. Discusses the ramifications of genetic concepts for social work profession. (Author/ABL)

  13. 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…

  14. [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

  15. The future of genetic epidemiology.

    PubMed

    Morton, N E

    1992-12-01

    Starting from a broad definition of genetic epidemiology, current developments in association, segregation, and linkage analysis of complex inheritance are considered together with integration of genetic and physical maps and resolution of genetic heterogeneity. Mitochondrial inheritance, imprinting, uniparental disomy, pregressive amplification, and gonadal mosaicism are some of the novel mechanisms discussed, with speculation about the future of genetic epidemiology.

  16. 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)

  17. 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)

  18. Genetics and educational psychology.

    PubMed

    Plomin, Robert; Walker, Sheila O

    2003-03-01

    Molecular genetics, one of the most energetic and exciting areas of science, is slowly but surely coming to educational psychology. We review recent molecular genetic research on learning disabilities as a sign of things to come in educational psychology. We also consider some misconceptions about genetics that have slowed the acceptance of genetics in educational psychology. Diverse samples of children with learning disabilities have been studied, primarily in the UK and the USA. Linkage analysis can detect genes that have large effects on learning disabilities. Association analysis can detect genes of much smaller effect size, which is important because common disorders such as learning disabilities are likely to be influenced by many genes as well as by many environmental factors. For reading disability, replicated linkages have been identified on chromosomes 6, 15 and 18. A gene responsible for a rare type of language impairment has recently been identified. For common language impairment, linkages on chromosomes 16 and 19 have recently been reported. More than 200 genetic disorders, most extremely rare, include mental retardation among their symptoms, and chromosomal abnormalities are a major cause of mental retardation. Although finding specific genes associated with learning disabilities is unlikely to have much of a direct application for teachers in the classroom, such findings will have far-reaching implications for diagnosis, treatment and prevention of learning disabilities and for research in educational psychology. Educational psychology has been slower to accept evidence for the importance of genetics than other areas of psychology in part because of misconceptions about what it means to say that genetics is important for common complex disorders such as learning disabilities.

  19. Genetics of human hydrocephalus

    PubMed Central

    Williams, Michael A.; Rigamonti, Daniele

    2006-01-01

    Human hydrocephalus is a common medical condition that is characterized by abnormalities in the flow or resorption of cerebrospinal fluid (CSF), resulting in ventricular dilatation. Human hydrocephalus can be classified into two clinical forms, congenital and acquired. Hydrocephalus is one of the complex and multifactorial neurological disorders. A growing body of evidence indicates that genetic factors play a major role in the pathogenesis of hydrocephalus. An understanding of the genetic components and mechanism of this complex disorder may offer us significant insights into the molecular etiology of impaired brain development and an accumulation of the cerebrospinal fluid in cerebral compartments during the pathogenesis of hydrocephalus. Genetic studies in animal models have started to open the way for understanding the underlying pathology of hydrocephalus. At least 43 mutants/loci linked to hereditary hydrocephalus have been identified in animal models and humans. Up to date, 9 genes associated with hydrocephalus have been identified in animal models. In contrast, only one such gene has been identified in humans. Most of known hydrocephalus gene products are the important cytokines, growth factors or related molecules in the cellular signal pathways during early brain development. The current molecular genetic evidence from animal models indicate that in the early development stage, impaired and abnormal brain development caused by abnormal cellular signaling and functioning, all these cellular and developmental events would eventually lead to the congenital hydrocephalus. Owing to our very primitive knowledge of the genetics and molecular pathogenesis of human hydrocephalus, it is difficult to evaluate whether data gained from animal models can be extrapolated to humans. Initiation of a large population genetics study in humans will certainly provide invaluable information about the molecular and cellular etiology and the developmental mechanisms of human

  20. Pregnancy, cardiomyopathies, and genetics.

    PubMed

    Van Tintelen, J Peter; Pieper, Petronella G; Van Spaendonck-Zwarts, Karin Y; Van Den Berg, Maarten P

    2014-03-15

    Although familial forms of cardiomyopathy such as hypertrophic or dilated cardiomyopathy have been recognized for decades, it is only recently that much of the genetic basis of these inherited cardiomyopathies has been elucidated. This has provided important insights into the pathophysiological mechanisms underlying the disease phenotype. This increased knowledge and the availability of genetic testing has resulted in increasing numbers of mutation carriers who are being monitored, including many who are now of child-bearing age. Pregnancy is generally well tolerated in asymptomatic patients or mutation carriers with inherited cardiomyopathies. However, since pregnancy leads to major physiological changes in the cardiovascular system, in women with genetic cardiomyopathies or who carry a mutation pre-disposing to a genetic cardiomyopathy, pregnancy entails a risk of developing heart failure and/or arrhythmias. This deterioration of cardiac function may occur despite optimal medical treatment. Advanced left ventricular dysfunction, poor functional class (NYHA class III or IV), or prior cardiac events appear to increase the risk of maternal cardiac complications. However, there are no large series of cardiomyopathy patients who are regularly evaluated for cardiac complications during pregnancy and for certain types of inherited cardiomyopathy, only case reports on individual pregnancies are available. Pre-conception cardiologic evaluation and genetic counselling are important for every woman with a cardiomyopathy or a cardiomyopathy-related mutation who is considering having a family. In this article, we give an overview of the basic clinical aspects, genetics, and pregnancy outcome in women with different types of inherited cardiomyopathies. We also discuss the genetic aspects of pregnancy-associated cardiomyopathy, including peripartum cardiomyopathy.

  1. Genetic of uveitis.

    PubMed

    Pichi, Francesco; Carrai, Paola; Srivastava, Sunil K; Lowder, Careen Y; Nucci, Paolo; Neri, Piergiorgio

    2016-06-01

    Immune-mediated uveitis may be associated with a systemic disease or may be localized to the eye. T-cell-dependent immunological events are increasingly being regarded as extremely important in the pathogenesis of uveitis. Several studies have also shown that macrophages are major effectors of tissue damage in uveitis. Uveitis phenotypes can differ substantially, and most uveitis diseases are considered polygenic with complex inheritance patterns. This review attempts to present the current state of knowledge from in vitro and in vivo research on the role of genetics in the development and clinical course of uveitis. A review of the literature in the PubMed, MEDLINE, and Cochrane databases was conducted to identify clinical trials, comparative studies, case series, and case reports describing host genetic factors as well as immune imbalance which contribute to the development of uveitis. The search was limited to primary reports published in English with human subjects from 1990 to the present, yielding 3590 manuscripts. In addition, referenced articles from the initial searches were hand searched to identify additional relevant reports. After title and abstract selection, duplicate elimination, and manual search, 55 papers were selected for analysis and reviewed by the authors for inclusion in this review. Studies have demonstrated associations between various genetic factors and the development and clinical course of intraocular inflammatory conditions. Genes involved included genes expressing interleukins, chemokines, chemokine receptors, and tumor necrosis factor and genes involved in complement system. When considering the genetics of uveitis, common threads can be identified. Genome-wide scans and other genetic methods are becoming increasingly successful in identifying genetic loci and candidate genes in many inflammatory disorders that have a uveitic component. It will be important to test these findings as uveitis-specific genetic factors. Therefore, the

  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. Moral issues arising from genetics.

    PubMed

    Zucker, A; Patriquin, D

    1987-01-01

    Gene therapy, pre-natal diagnosis, genetically altered bacteria, patenting new life forms: these are all outgrowths from the development of genetics. Our focus will be on the moral issues engendered by some of the genetic techniques which are now so well integrated into clinical medicine. The section on genetic counseling is meant to show the most frequent moral problems encountered as they might really occur. Genetic screening is presented as a mix of preventive medicine and aid for genetic counseling. Genetic engineering is discussed in the context of evolution and human needs and desires.

  4. Field validation of a battery of biomarkers to assess sediment quality in Spanish ports.

    PubMed

    Martín-Díaz, M L; Blasco, J; Sales, D; Delvalls, T A

    2008-02-01

    Two marine invertebrates, the crab Carcinus maenas and the clam Ruditapes philippinarum, were used as bioindicator species to assess contamination when exposed in situ to sediment from different sites from four Spanish ports Cadiz (SW Spain), Huelva (SW Spain), Bilbao (NE Spain) and Pasajes (NE Spain). In an attempt to determine sediments toxicity, a combination of exposure biomarkers was analyzed in both species: metallothionein-like-proteins (MTLPs), ethoxyresorufin O-deethylase (EROD), glutathione S-transferase activity (GST), glutathione peroxidase (GPX) and glutathione reductase (GR). In parallel, physical and chemical characterization of the different sediments was performed and biological responses related to the contaminants. Significant induction of MTLPs was observed when organisms were exposed to metal contaminated sediments (port of Huelva), and EROD and GPX activities after exposure to sediments containing organic compounds (port of Bilbao and Pasajes). No significant interspecies differences were observed in biomarker responses except for the GST and GR.

  5. Immunochemical and immunocytochemical studies of the crustacean vitellogenesis-inhibiting hormone (VIH).

    PubMed

    Meusy, J J; Martin, G; Soyez, D; van Deijnen, J E; Gallo, J M

    1987-09-01

    Immunochemical investigations, using dot immunobinding assay (DIA) and enzyme-linked immunosorbent assay (ELISA), and immunocytochemical studies reveal the following new information about crustacean vitellogenesis-inhibiting hormone (VIH): (1) The structure of VIH is sufficiently different from that of the other sinus gland neuropeptides to allow a selective recognition of VIH by polyclonal antibodies. (2) From immunochemical criteria, VIH does not seem strictly species specific. The antisera raised against VIH of Homarus americanus cross-react with sinus gland extracts of Palaemonetes varians, Palaemon serratus, Macrobrachium rosenbergii, Carcinus maenas, and Porcellio dilatatus. (3) In the sinus gland of H. americanus, VIH immunoreactivity is localized mainly in electron-dense granules of medium size (110-185 nm in diameter) while, in P. dilatatus, the labeling is mostly on the largest granules (200-270 nm in diameter).

  6. The crab Neohelice (= Chasmagnathus) granulata: an emergent animal model from emergent countries

    NASA Astrophysics Data System (ADS)

    Spivak, Eduardo D.

    2010-09-01

    Neohelice granulata (previously known as Chasmagnathus granulata and C. granulatus) is a burrowing semiterrestrial crab found in the intertidal zone of estuaries, salt marshes and mangroves of the South-western Atlantic Ocean. Beginning in the late 1989s, an explosion of publications appeared in international journals dealing with its ecology, physiology, toxicology and behavior. A bibliometric analysis using the Scopus database allowed detecting 309 papers that deal with this species during the period 1986-2009. The number of papers per year increased continuously, reaching a mean annual value of 22.6 during the last 5 years; a great majority of them were authored by researchers from Argentina and Brazil. Neohelice granulata has become now one of the most studied crab species, after Carcinus maenas, Callinectes sapidus, Scylla serrata and Cancer pagurus and C. magister, and it can be considered as an emergent animal model for biochemical, physiological and ecological research.

  7. Milky hemolymph syndrome (MHS) in spiny lobsters, penaeid shrimp and crabs.

    PubMed

    Nunan, Linda M; Poulos, Bonnie T; Navarro, Solangel; Redman, Rita M; Lightner, Donald V

    2010-09-02

    Black tiger shrimp Penaeus monodon, European shore crab Carcinus maenas and spiny lobster Panulirus spp. can be affected by milky hemolymph syndrome (MHS). Four rickettsia-like bacteria (RLB) isolates of MHS originating from 5 geographical areas have been identified to date. The histopathology of the disease was characterized and a multiplex PCR assay was developed for detection of the 4 bacterial isolates. The 16S rRNA gene and 16-23S rRNA intergenic spacer region (ISR) were used to examine the phylogeny of the MHS isolates. Although the pathology of this disease appears similar in the various different hosts, sequencing and examination of the phylogenetic relationships reveal 4 distinct RLB involved in the infection process.

  8. Mechanism of a plastic phenotypic response: predator-induced shell thickening in the intertidal gastropod Littorina obtusata.

    PubMed

    Brookes, J I; Rochette, Rémy

    2007-05-01

    Phenotypic plasticity has been the object of considerable interest over the past several decades, but in few cases are mechanisms underlying plastic responses well understood. For example, it is unclear whether predator-induced changes in gastropod shell morphology represent an active physiological response or a by-product of reduced feeding. We address this question by manipulating feeding and growth of intertidal snails, Littorina obtusata, using two approaches: (i) exposure to predation cues from green crabs Carcinus maenas and (ii) reduced food availability, and quantifying growth in shell length, shell mass, and body mass, as well as production of faecal material and shell micro-structural characteristics (mineralogy and organic fraction) after 96 days. We demonstrate that L. obtusata actively increases calcification rate in response to predation threat, and that this response entails energetic and developmental costs. That this induced response is not strictly tied to the animal's behaviour should enhance its evolutionary potential.

  9. MISE EN EVIDENCE ET ETUDE CYTOCHIMIQUE D'UNE PROTEINE BASIQUE EXTRANUCLEAIRE DANS LES SPERMATOZOIDES DES CRUSTACES DECAPODES

    PubMed Central

    Chevaillier, Philippe

    1967-01-01

    Extranuclear basic proteins have been detected in the capsule of the spermatozoa of three species of decapod crustaceans (Nephrops norvegicus L., Macrura; Eupagurus bernhardus L., Anomura; Carcinus maenas Penn., Brachyura). Their properties have been studied by cytochemical methods. Their position inside the capsule of the spermatozoon has been specified with the aid of the electron microscope. Present in a constant fashion in the three species cited, their relative importance is very variable. In contrast to the refringent cone of the spermatozoon of Ascaris, which contains an acid protein, ascaradine, the capsule of the spermatozoon of the three decapod crustaceans studied contains basic proteins which we propose to designate by the general term "decapodine". PMID:6068078

  10. Predation on barnacles of intertidal and subtidal mussel beds in the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Buschbaum, Christian

    2002-04-01

    Balanids are the numerically dominant epibionts on mussel beds in the Wadden Sea. Near the island of Sylt (German Bight, North Sea), Semibalanus balanoides dominated intertidally and Balanus crenatus subtidally. Field experiments were conducted to test the effects of predation on the density of barnacle recruits. Subtidally, predator exclusion resulted in significantly increased abundances of B. crenatus, while predator exclusion had no significant effects on the density of S. balanoides intertidally. It is suggested that recruitment of B. crenatus to subtidal mussel beds is strongly affected by adult shore crabs ( Carcinus maenas) and juvenile starfish ( Asterias rubens), whereas recruits of S. balanoides in the intertidal zone are mainly influenced by grazing and bulldozing of the very abundant periwinkle Littorina littorea, which is rare subtidally. Thus, not only do the barnacle species differ between intertidal and subtidal mussel beds, but the biotic control factors do so as well.

  11. Temporal characterization of mercury accumulation at different trophic levels and implications for metal biomagnification along a coastal food web.

    PubMed

    Cardoso, P G; Pereira, E; Duarte, A C; Azeiteiro, U M

    2014-10-15

    The main goal of this study was to assess temporal mercury variations along an estuarine food web to evaluate the mercury contamination level of the system and the risks that humans are exposed to, due to mercury biomagnification. The highest mercury concentrations in the sediments and primary producers (macrophytes) were observed during winter sampling. Instead, the highest mercury concentrations in the water, suspended particulate matter as well as in the zooplanktonic and suprabenthic communities were observed during summer sampling. Evidences of mercury biomagnification along the food web were corroborated by the positive biomagnification factors, particularly for omnivorous macrobenthic species. Comparing the mercury levels at distinct components with several environmental quality criteria it suggests that sediments, water and edible species (e.g., bivalve Scrobicularia plana and the crustacean Carcinus maenas) presented higher mercury levels than the values accepted by legislation which represent a matter of concern for the environment and human health.

  12. Protein phosphorylation and sodium conductance in nerve membrane.

    PubMed Central

    Schoffeniels, E; Dandrifosse, G

    1980-01-01

    High molecular weight proteins extracted from the walking nerves of the shore crab (Carcinus maenas) exhibit a cycle of phosphorylation-dephosphorylation that is influenced by neurotropic compounds and inorganic ions. The net phosphorylation state of the proteins is increased in the presence of K+ ions and decreased with Na+ ions. In the absence of Mg2+ there is no phosphorylation. Ca2+ ions at low concentrations are necessary for optimal phosphorylation. At high concentration (above 0.1 mM), Ca2+ ions are inhibitory. Neurotropic compounds generally inhibit the phosphorylation process. More specifically, tetrodotoxin and veratridine, depending on the ionic composition of the medium, have opposite effects on the phosphorylation process, a result in agreement with their known physiological action. It is suggested that the high molecular weight components thus identified are part of the sodium permeation sites and that the conductance state of those sites is controlled by a phosphorylation process. Images PMID:6928680

  13. Circular dichroism study of the hemocyanin thermostability

    NASA Astrophysics Data System (ADS)

    Nikolova Georgieva, Dessislava; Stoeva, Stanka; Abid Ali, Syed; Abbasi, Atiya; Genov, Nicolay; Voelter, Wolfgang

    1998-05-01

    Circular dichroism spectroscopy is used to investigate the thermostability of six arthropod hemocyanins (Hcs), representatives of the subphyla Crustacea (infraorder Brachyura) and Chelicerate (infraorders Xiphosura and Arachnida), and three molluscan Hcs from gastropod organisms. Melting points ( Tm) are determined from the temperature dependence of ellipticity of dioxygen-binding proteins from Maia squinado, Callinectes sapidus, Carcinus maenas, Limulus polyphemus, Buthus sindicus, Androctonus australis, Megathura crenulata, Haliotis tuberculata, and Rapana thomasiana. Both, arthropod and molluscan Hcs, are thermostable proteins with melting temperatures in the region 68-91°C. Binuclear dioxygen-binding sites contribute significantly to the thermostability and increase the Tm values of the apo-forms by 3-16°C. An elevated thermostability is observed in the case of the Limulus polyphemus Hc. One of the reasons is the high degree of hemocyanin oligomerization.

  14. Toxicity and accumulation of mercury in three species of crabs with different osmoregulatory capacities

    SciTech Connect

    Bianchini, A.; Gilles, R.

    1996-07-01

    Synergism between mercury and salinity has been shown in invertebrates. Two authors have tied to correlate salinity effects with a higher or lower accumulation of mercury. Zauke, demonstrated lower mercury levels in several benthic invertebrates from limnic regions of the Elbe estuary when compared to those from Marine regions. On the other hand, Kendall did not report any significant difference in mercury concentrations in benthic macroinvertebrates throughout a salinity gradient in two estuaries from Georgia. In species hyperosmoregulating in diluted media, it could, however, be considered that the high water turnover would favor mercury accumulation. In this context, one could also expect a relationship between environmental salinity and mercury toxicity in different euryhaline species depending on their osmoregulatory capacities. We have tested this hypothesis analyzing the toxic effects and accumulation of mercury in three euryhaline crabs presenting different osmoregulatory capacities: Eriocheir sinensis (strong hyperosmoregulator), Carcinus maenas (weak hyperosmoregulator) and Cancer pagurus (osmoconformer). 16 refs., 4 figs., 1 tab.

  15. 'Take-away' foraging spatially uncouples predator and prey-attack distributions.

    PubMed

    Smallegange, Isabel M; van der Meer, Jaap; Sabelis, Maurice W

    2010-07-01

    1. Ideal-free distribution theory assumes that in a patchy environment foragers maximize fitness and hence their feeding rate by balancing gains from more food against losses from more competition. Ultimately, individuals cannot increase their feeding rate by moving to another patch and they distribute themselves over patches in proportion to prey density per patch. 2. In our experiments with shore crabs Carcinus maenas foraging on two adjacent patches with mussels Mytilus edulis, the implicit assumption of ideal-free distribution theory that catch should match time spent in a prey patch is not met, however. Despite aggregating their attack where it is most profitable shore crabs distributed themselves homogeneously across mussel patches: they 'take away' the prey caught and consume it elsewhere to reduce interference. 3. Thus, predator distributions can be quite different from prey-attack distributions. This is important because the latter is shown to be decisive for persistence of predator and prey populations in ecological models.

  16. 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 ...

  17. Genetic Susceptibility to Lymphoma

    PubMed Central

    Skibola, Christine F.; Curry, John D.; Nieters, Alexandra

    2010-01-01

    BACKGROUND Genetic susceptibility studies of lymphoma may serve to identify at risk populations and to elucidate important disease mechanisms. METHODS This review considered all studies published through October 2006 on the contribution of genetic polymorphisms in the risk of lymphoma. RESULTS Numerous studies implicate the role of genetic variants that promote B-cell survival and growth with increased risk of lymphoma. Several reports including a large pooled study by InterLymph, an international consortium of non-Hodgkin lymphoma (NHL) case-control studies, found positive associations between variant alleles in TNF -308G>A and IL10 -3575T>A genes and risk of diffuse large B-cell lymphoma. Four studies reported positive associations between a GSTT1 deletion and risk of Hodgkin and non-Hodgkin lymphoma. Genetic studies of folate-metabolizing genes implicate folate in NHL risk, but further studies that include folate and alcohol assessments are needed. Links between NHL and genes involved in energy regulation and hormone production and metabolism may provide insights into novel mechanisms implicating neuro- and endocrine-immune cross-talk with lymphomagenesis, but will need replication in larger populations. CONCLUSIONS Numerous studies suggest that common genetic variants with low penetrance influence lymphoma risk, though replication studies will be needed to eliminate false positive associations. PMID:17606447

  18. 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

  19. Microtia: epidemiology and genetics.

    PubMed

    Luquetti, Daniela V; Heike, Carrie L; Hing, Anne V; Cunningham, Michael L; Cox, Timothy C

    2012-01-01

    Microtia is a congenital anomaly of the ear that ranges in severity from mild structural abnormalities to complete absence of the ear, and can occur as an isolated birth defect or as part of a spectrum of anomalies or a syndrome. Microtia is often associated with hearing loss and patients typically require treatment for hearing impairment and surgical ear reconstruction. The reported prevalence varies among regions, from 0.83 to 17.4 per 10,000 births, and the prevalence is considered to be higher in Hispanics, Asians, Native Americans, and Andeans. The etiology of microtia and the cause of this wide variability in prevalence are poorly understood. Strong evidence supports the role of environmental and genetic causes for microtia. Although some studies have identified candidate genetic variants for microtia, no causal genetic mutation has been confirmed. The application of novel strategies in developmental biology and genetics has facilitated elucidation of mechanisms controlling craniofacial development. In this paper we review current knowledge of the epidemiology and genetics of microtia, including potential candidate genes supported by evidence from human syndromes and animal models. We also discuss the possible etiopathogenesis in light of the hypotheses formulated to date: Neural crest cells disturbance, vascular disruption, and altitude.

  20. Genetics and smoking

    PubMed Central

    Loukola, Anu; Hällfors, Jenni; Korhonen, Tellervo; Kaprio, Jaakko

    2014-01-01

    Regular smoking is the major risk factor for cardiovascular disease and cancers, and thus is one of the most preventable causes of morbidity and mortality worldwide. Intake of nicotine, its central nervous system effects, and its metabolism are regulated by biological pathways; some of these are well known, but others are not. Genetic studies offer a method for developing insights into the genes contributing to those pathways. In recent years, large genome-wide association study (GWAS) meta-analyses have consistently revealed that the strongest genetic contribution to smoking-related traits comes from variation in the nicotinic receptor subunit genes. Many other genes, including those coding for enzymes involved in nicotine metabolism, also have been implicated. However, the proportion of phenotypic variance explained by the identified genetic variants is very modest. This review intends to cover progress made in genetics and genetic epidemiology of smoking behavior in recent years, and focuses on studies revealing the nicotinic receptor gene cluster on chromosome 15q25. Evidence supporting the involvement of a novel pathway in the shared pathophysiology of nicotine dependence and schizophrenia is also briefly reviewed. A summary of the current knowledge on gene–environment interactions involved in smoking behavior is included. PMID:24778978

  1. 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.

  2. [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.

  3. 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

  4. Genetics of Clubfoot

    PubMed Central

    DOBBS, Matthew B; GURNETT, Christina A

    2011-01-01

    Modern advances in genetics have allowed investigators to begin to identify the complex etiology of clubfoot. It has become increasingly apparent that clubfoot is a heterogeneous disorder with a polygenetic threshold model explaining its inheritance patterns. Several recent genetics studies have identified a key developmental pathway, the PITX1-TBX4 transriptional pathway, as being important in clubfoot etiology. Both PITX1 and TBX4 are uniquely expressed in the hindlimb which helps explain the foot phenotype seen with mutations in these transcription factors. Future studies are needed to develop animal models to determine the exact mechanisms by which these genetic abnormalities cause clubfoot and to test other hypotheses of clubfoot pathogenesis. PMID:21817922

  5. Whakapapa, genealogy and genetics.

    PubMed

    Evans, Donald

    2012-05-01

    This paper provides part of an analysis of the use of the Maori term whakapapa in a study designed to test the compatibility and commensurability of views of members of the indigenous culture of New Zealand with other views of genetic technologies extant in the country. It is concerned with the narrow sense of whakapapa as denoting biological ancestry, leaving the wider sense of whakapapa as denoting cultural identity for discussion elsewhere. The phenomenon of genetic curiosity is employed to facilitate this comparison. Four levels of curiosity are identified, in the Maori data, which penetrate more or less deeply into the psyche of individuals, affecting their health and wellbeing. These phenomena are compared with non-Maori experiences and considerable commonalities are discovered together with a point of marked difference. The results raise important questions for the ethical application of genetic technologies.

  6. Genetic modification in floriculture.

    PubMed

    Chandler, Stephen F; Brugliera, Filippa

    2011-02-01

    Micro-propagation, embryo rescue, mutagenesis via chemical or irradiation means and in vitro inter-specific hybridisation methods have been used by breeders in the floriculture industry for many years. In the past 20 years these enabling technologies have been supplemented by genetic modification methods. Though many genes of potential utility to the floricultural industry have been identified, and much has been learnt of the genetic factors and molecular mechanisms underlying phenotypes of great importance to the industry, there are only flower colour modified varieties of carnation and rose in the marketplace. To a large extent this is due to unique financial barriers to market entry for genetically modified varieties of flower crops, including use of technology fees and costs of regulatory approval.

  7. Genetics of bipolar disorder.

    PubMed

    Escamilla, Michael A; Zavala, Juan M

    2008-01-01

    Bipolar disorder especially the most severe type (type I), has a strong genetic component. Family studies suggest that a small number of genes of modest effect are involved in this disorder. Family-based studies have identified a number of chromosomal regions linked to bipolar disorder, and progress is currently being made in identifying positional candidate genes within those regions. A number of candidate genes have also shown evidence of association with bipolar disorder, and genome-wide association studies are now under way, using dense genetic maps. Replication studies in larger or combined datasets are needed to definitively assign a role for specific genes in this disorder. This review covers our current knowledge of the genetics of bipolar disorder, and provides a commentary on current approaches used to identify the genes involved in this complex behavioral disorder.

  8. Genetics of fibromyalgia.

    PubMed

    Buskila, Dan; Neumann, Lily

    2005-10-01

    The pathogenesis of fibromyalgia (FM) and related conditions is not entirely understood. Recent evidence suggests that these syndromes may share heritable pathophysiologic features. Familial studies suggest that genetic and familial factors may play a role in the etiopathogenesis of these conditions. There is evidence that polymorphisms of genes in the serotoninergic and catecholaminergic systems are linked to the pathophysiology of FM and related conditions and are associated with personality traits. The precise role of genetic factors in the etiopathology of FM remains unknown, but it is likely that several genes are operating together to initiate this syndrome. Larger longitudinal studies are needed to better clarify the role of genetics in the development of FM.

  9. 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.

  10. [Genetic aspects of schizophrenia].

    PubMed

    Morozova, A Yu; Zubkov, E A; Zorkina, Ya A; Reznik, A M; Kostyuk, G P; Chekhonin, V P

    Schizophrenia is a disease with a complex non-Mendelian inheritance mechanism in most cases involving the combined action of a large number of genes. Identifying of genomic variations associated with schizophrenia endophenotypes has a great potential. This review describes genetic markers of the disease, current methods of their analysis, including genome-wide association study (GWAS). Certain genes with mutations that increase the risk of schizophrenia are described. Functional polymorphisms with phenotypic expression, which are significantly associated with clinical manifestation of schizophrenia, can serve as useful genetic markers. The authors highlight that currently there are no certain susceptibility genes. Further global research and search for markers in different population groups are needed.

  11. Genetics of Alzheimer Disease

    PubMed Central

    Bekris, Lynn M.; Yu, Chang-En; Bird, Thomas D.; Tsuang, Debby W.

    2011-01-01

    Alzheimer disease (AD) is the most common causes of neurodegenerative disorder in the elderly individuals. Clinically, patients initially present with short-term memory loss, subsequently followed by executive dysfunction, confusion, agitation, and behavioral disturbances. Three causative genes have been associated with autosomal dominant familial AD (APP, PSEN1, and PSEN2) and 1 genetic risk factor (APOEε4 allele). Identification of these genes has led to a number of animal models that have been useful to study the pathogenesis underlying AD. In this article, we provide an overview of the clinical and genetic features of AD. PMID:21045163

  12. [Comparative morphological and physiological studies of the integumentary tissue and the content of molting hormone in the crayfish Orconectes limosus during a molt cycle].

    PubMed

    Keller, R; Adelung, D

    1970-09-01

    The structural changes in the integumentary tissues during a molt cycle of the crayfishOrconectes limosus and the stages of the molt cycle are described. The incorporation of uridine-5-H(3) into the nuclei of the epidermis and the tegumental glands during the molt cycle was determined by autoradiography and grain counting. In the epidermal nuclei the incorporation reaches a peak immediately before molt; a first, poorly expressed peak seems to be reached in stageD 1 which is characterized by apolysis and the preparation for secretion of the new epicuticle. In the early premolt stages (D0, D1) the activity of the tegumental gland nuclei compared to that of the epidermal nuclei is higher than in the later premolt stages. A first peak is reached in stage D1, a second one of similar size in stage D4. In stage D2, during and shortly after the secretion of the new epicuticle, heavily labelled hemolymph cells are found in the integumentary tissue beneath the epidermis and between the epidermal cells.Compared toCarcinus maenas only an approximative estimation of the hormone titer could be achieved. This is due to technical difficulties in connection with the very low hormone content of the crayfish. Measurable amounts could be detected between the premolt stages D0 and D3. In this period a rise of the RNA synthesis was observed. The peak of RNA synthesis follows the peak of the molting hormone with a certain delay. This is in accordance with the hypothesis of hormonal control of RNA synthesis during the molt cycle in arthropods. A comparison of the time course of RNA synthesis in the crayfish with the better known time course of the hormone content inCarcinus maenas exhibits a good accordance.

  13. Genetics for the General Internist

    PubMed Central

    Laukaitis, Christina M.

    2011-01-01

    The internist’s goal is to determine a patient’s disease risk and to implement preventative interventions. Genetic evaluation is a powerful risk assessment tool and new interventions target previously untreatable genetic disorders. The purpose of this review is to educate the general internist about common genetic conditions affecting adult patients with special emphasis on diagnoses with an effective intervention, including hereditary cancer syndromes and cardiovascular disorders. Basic tenets of genetic counseling, complex genetic disease and management of adults with genetic diagnoses are also discussed. PMID:22079017

  14. Genetics for the general internist.

    PubMed

    Laukaitis, Christina M

    2012-01-01

    The internist's goal is to determine a patient's disease risk and to implement preventative interventions. Genetic evaluation is a powerful risk assessment tool, and new interventions target previously untreatable genetic disorders. The purpose of this review is to educate the general internist about common genetic conditions affecting adult patients, with special emphasis on diagnoses with an effective intervention, including hereditary cancer syndromes and cardiovascular disorders. Basic tenets of genetic counseling, complex genetic disease, and management of adults with genetic diagnoses also are discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. 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…

  16. Genetic diversity within species

    Treesearch

    D. L. Rogers; C. I. Millar; R. D Westfall

    1996-01-01

    Based on our review of literature and survey of geneticists workingon California taxa, we find genetic information lacking for most speciesin the Sierra Nevada. This situation is likely to remain infuture, with specific groups of taxa or occasional rare or high-interestspecies receiving specific study. Where we do have empirical information,we find few generalities...

  17. 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…

  18. 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.

  19. The genetics of obesity.

    USDA-ARS?s Scientific Manuscript database

    All definitions of the metabolic syndrome include some form of obesity as one of the possible features. Body mass index (BMI) has a known genetic component, currently estimated to account for about 70% of the population variance in weight status for non-syndromal obesity. Much research effort has be...

  20. Genetic transformation in conifers

    Treesearch

    S.C. Minocha; R. Minocha

    1999-01-01

    Several attempts at the genetic improvement of tree species have been made, but in comparison with crop plants the efforts as well as the results have been rather limited. The most commonly used approaches have involved selection of superior genotypes from natural outbred populations, mutations, and intra- and inter-specific hybridization under controlled conditions....

  1. Longleaf Pine Genetics

    Treesearch

    Ronald C. Schmidtling

    1999-01-01

    There has been a movement of late toward the use of natural regeneration for iongieaf pine (Pinus palustris Mill.) as well as for other forest tree species. If you have a good natural stand, and have plenty of time, natural regeneration will result in a suitable stand, and genetics is not relevant.

  2. Genetics and immunology: reinvigorated

    PubMed Central

    Snyder, Alexandra; Makarov, Vladimir; Hellmann, Matthew; Rizvi, Naiyer; Merghoub, Taha; Wolchok, Jedd D; Chan, Timothy A

    2015-01-01

    Immune checkpoint blockade therapy is changing oncology by improving the outcome of patients with advanced malignancies. Our research has revealed the genetic features of tumors present in patients who initiate a successful antitumor immune response and derive clinical benefit from immune checkpoint blockade therapy versus non-responders. PMID:26451299

  3. Prenatal Genetic Testing Chart

    MedlinePlus

    ... www.acog.org/Patients/FAQs/Prenatal-Genetic-Diagnostic-Tests › › Resources & Publications Committee Opinions Practice Bulletins Patient Education Green Journal Clinical Updates Practice Management Coding Health Info Technology Professional Liability Managing Your Practice Patient Safety & Quality ...

  4. 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…

  5. Genetics and variation

    Treesearch

    John R. Jones; Norbert V. DeByle

    1985-01-01

    The broad genotypic variability in quaking aspen (Populus tremuloides Michx.), that results in equally broad phenotypic variability among clones is important to the ecology and management of this species. This chapter considers principles of aspen genetics and variation, variation in aspen over its range, and local variation among clones. For a more...

  6. 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.

  7. 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…

  8. 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…

  9. 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…

  10. New sunflower genetics

    USDA-ARS?s Scientific Manuscript database

    Genetic research of the sunflower research unit, USDA-ARS, in Fargo, ND, was discussed in a presentation to a group of Canadian producers, industry representatives, and scientists. Because this was an international audience, I introduced the audience to ARS and the structure of the sunflower unit, a...

  11. The genetics of Tamarix

    USDA-ARS?s Scientific Manuscript database

    Genetic studies have helped us gain basic knowledge of the Tamarix invasion. We now have a better understanding of the species identities involved in the invasion, their evolutionary relationships, and the contribution of hybridization to the invasion. This information can be used to enhance the eff...

  12. Prenatal Genetic Counselling

    PubMed Central

    McGillivray, Barbara C.

    1986-01-01

    Genetic concerns and indications for prenatal diagnosis are first recognized by the family physician. Review of personal, pregnancy and family history may indicate concerns beyond that of advanced maternal age. Amniocentesis is still the most frequently used modality for prenatal diagnosis, but detailed ultrasound is valuable for structural abnormalities, and chorionic villus sampling is now being tested as an alternative to amniocentesis. PMID:21267316

  13. Genetic Resources of Watermelon

    USDA-ARS?s Scientific Manuscript database

    As a result of many years of domestication and selection for desirable fruit quality, watermelon cultivars (Citrullus lanatus) share a narrow genetic base. Africa is the center of origin and diversity of watermelon and is considered to be the central continent for collecting and conserving useful ge...

  14. Metaphorical Reasoning about Genetics.

    ERIC Educational Resources Information Center

    Martins, Isabel; Ogborn, Jon

    1997-01-01

    Describes a study of how people use metaphors to make sense of scientific phenomena and ideas in a process of extended group discussion. Interviews that involved reading an edited scientific text on DNA then discussing a number of questions about various aspects of genetics provide the data for this study. Contains 16 references. (DDR)

  15. Breeding and genetic diversity

    USDA-ARS?s Scientific Manuscript database

    Corn breeding has been historically remarkably successful. Much research has investigated optimal breeding procedures, which are detailed here. A smaller effort has been put into identifying useful genetic resources for maize and how to best use them, but results from long-term base broadening effor...

  16. 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…

  17. Genetics and Genomics

    USDA-ARS?s Scientific Manuscript database

    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...

  18. Teaching Genetics in Schools.

    ERIC Educational Resources Information Center

    Radford, A.; Bird-Stewart, J. A.

    1982-01-01

    Discusses the genetics content in secondary school curricula, suggesting possible revisions to current A- and 0-level syllabi. Present teaching methods, textbooks, and General Certificate of Education (GCE) examination questions are reviewed, problems identified, and suggestions made regarding possible improvements. (Author/JN)

  19. Genetics and Educability

    ERIC Educational Resources Information Center

    Thoday, J. M.

    1972-01-01

    Indicates each individual has a unique genetic history that determines much of his potential for excellence in a field. Educational programs should be planned with consideration of these individual variations. Instead of formulating plans for groups of people, concentration should be given to individuals in a group. (PS)

  20. A century of genetics

    Treesearch

    Daniel J. Fairbanks

    2001-01-01

    In 1866, Gregor Mendel published his experiments on heredity in the garden pea (Pisum sativum). The fundamental principles of inheritance derived from his work apply to nearly all eukaryotic species and are now known as Mendelian principles. Since 1900, Mendel has been recognized as the founder of genetics. In 1900, three botanists, Carl Correns, Hugo De Vries, and...

  1. Genetic analysis of sleep

    PubMed Central

    Crocker, Amanda; Sehgal, Amita

    2010-01-01

    Almost 20 years ago, the gene underlying fatal familial insomnia was discovered, and first suggested the concept that a single gene can regulate sleep. In the two decades since, there have been many advances in the field of behavioral genetics, but it is only in the past 10 years that the genetic analysis of sleep has emerged as an important discipline. Major findings include the discovery of a single gene underlying the sleep disorder narcolepsy, and identification of loci that make quantitative contributions to sleep characteristics. The sleep field has also expanded its focus from mammalian model organisms to Drosophila, zebrafish, and worms, which is allowing the application of novel genetic approaches. Researchers have undertaken large-scale screens to identify new genes that regulate sleep, and are also probing questions of sleep circuitry and sleep function on a molecular level. As genetic tools continue to be refined in each model organism, the genes that support a specific function in sleep will become more apparent. Thus, while our understanding of sleep still remains rudimentary, rapid progress is expected from these recently initiated studies. PMID:20551171

  2. Genetics of metabolic syndrome.

    PubMed

    Stančáková, Alena; Laakso, Markku

    2014-12-01

    Metabolic syndrome (MetS) is a cluster of metabolic traits associated with an increased risk of cardiovascular disease and type 2 diabetes mellitus. Central obesity and insulin resistance are thought to play key roles in the pathogenesis of the MetS. The MetS has a significant genetic component, and therefore linkage analysis, candidate gene approach, and genome-wide association (GWA) studies have been applied in the search of gene variants for the MetS. A few variants have been identified, located mostly in or near genes regulating lipid metabolism. GWA studies for the individual components of the MetS have reported several loci having pleiotropic effects on multiple MetS-related traits. Genetic studies have provided so far only limited evidence for a common genetic background of the MetS. Epigenetic factors (DNA methylation and histone modification) are likely to play important roles in the pathogenesis of the MetS, and they might mediate the effects of environmental exposures on the risk of the MetS. Further research is needed to clarify the role of genetic variation and epigenetic mechanisms in the development of the MetS.

  3. 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…

  4. 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…

  5. 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.

  6. Genetic technologies and ethics.

    PubMed

    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.

  7. Genetic variability in Macadamia

    USDA-ARS?s Scientific Manuscript database

    A genetic variability analysis involving 45 accessions of Macadamia including four species, M. integrifolia, M. tetraphylla, M. ternifolia, and M. hildebrandii and a wild relative, Hicksbeachia pinnatifolia was performed usingeight enzyme systems encoded by 16 loci (Gpi-1 and 2, Idh-1 and 2, Lap, Md...

  8. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Maize Genetic Resources

    USDA-ARS?s Scientific Manuscript database

    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...

  10. 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.

  11. Can you keep a (genetic) secret? The genetic privacy movement.

    PubMed

    Everett, Margaret

    2004-08-01

    This paper reviews the literature on genetic privacy, especially since 1995 and the first proposal for national genetic privacy legislation. Since that time, a majority of states have passed some form of genetic privacy legislation, and efforts to pass federal legislation are ongoing. Such new laws, however, remain untested in the courts and their effects are unclear. If they fail to provide additional protections against discrimination for most people, their most significant impact may be in their ability to either diminish or enhance the power of genetic information and to influence the way individuals view themselves and others. How does "genetic exceptionalism"--the idea that genetic information is different from other types of medical information--relate to "genetic essentialism"--the idea that we are to a large extent shaped by our genes? Anthropological views on genetics and personhood bring a new perspective to this ongoing debate. Implications for counseling practices are also explored.

  12. The genetics of deafness.

    PubMed

    Nance, Walter E

    2003-01-01

    Deafness is an etiologically heterogeneous trait with many known genetic and environmental causes. Genetic factors account for at least half of all cases of profound congenital deafness, and can be classified by the mode of inheritance and the presence or absence of characteristic clinical features that may permit the diagnosis of a specific form of syndromic deafness. The identification of more than 120 independent genes for deafness has provided profound new insights into the pathophysiology of hearing, as well as many unexpected surprises. Although a large number of genes can clearly cause deafness, recessive mutations at a single locus, GJB2 or Connexin 26, account for more than half of all genetic cases in some, but not all populations. The high frequency may well be related to the greatly improved social, educational, and economic circumstances of the deaf that began with the introduction of sign language 300-400 years ago, along with a high frequency of marriages among the deaf in many countries. Similar mechanisms may account for the rapid fixation of genes for speech after the first mutations appeared 50,000-100,000 years ago. Molecular studies have shown that mutations involving several different loci may be the cause for the same form of syndromic deafness. Even within a single locus, different mutations can have profoundly different effects, leading to a different pattern of inheritance in some cases, or isolated hearing loss without the characteristic syndromic features in others. Most cases of genetic deafness result from mutations at a single locus, but an increasing number of examples are being recognized in which recessive mutations at two loci are involved. For example, digenic interactions are now known to be an important cause of deafness in individuals who carry a single mutation at the Connexin 26 locus along with a deletion involving the functionally related Connexin 30 locus. This mechanism complicates genetic evaluation and counseling, but

  13. 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].

  14. Genetic topography of brain morphology

    PubMed Central

    Chen, Chi-Hua; Fiecas, Mark; Gutiérrez, E. D.; Panizzon, Matthew S.; Eyler, Lisa T.; Vuoksimaa, Eero; Thompson, Wesley K.; Fennema-Notestine, Christine; Hagler, Donald J.; Jernigan, Terry L.; Neale, Michael C.; Franz, Carol E.; Lyons, Michael J.; Fischl, Bruce; Tsuang, Ming T.; Dale, Anders M.; Kremen, William S.

    2013-01-01

    Animal data show that cortical development is initially patterned by genetic gradients largely along three orthogonal axes. We previously reported differences in genetic influences on cortical surface area along an anterior-posterior axis using neuroimaging data of adult human twins. Here, we demonstrate differences in genetic influences on cortical thickness along a dorsal-ventral axis in the same cohort. The phenomenon of orthogonal gradations in cortical organization evident in different structural and functional properties may originate from genetic gradients. Another emerging theme of cortical patterning is that patterns of genetic influences recapitulate the spatial topography of the cortex within hemispheres. The genetic patterning of both cortical thickness and surface area corresponds to cortical functional specializations. Intriguingly, in contrast to broad similarities in genetic patterning, two sets of analyses distinguish cortical thickness and surface area genetically. First, genetic contributions to cortical thickness and surface area are largely distinct; there is very little genetic correlation (i.e., shared genetic influences) between them. Second, organizing principles among genetically defined regions differ between thickness and surface area. Examining the structure of the genetic similarity matrix among clusters revealed that, whereas surface area clusters showed great genetic proximity with clusters from the same lobe, thickness clusters appear to have close genetic relatedness with clusters that have similar maturational timing. The discrepancies are in line with evidence that the two traits follow different mechanisms in neurodevelopment. Our findings highlight the complexity of genetic influences on cortical morphology and provide a glimpse into emerging principles of genetic organization of the cortex. PMID:24082094

  15. 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…

  16. 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…

  17. 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.

  18. Genetics Home Reference: Poland syndrome

    MedlinePlus

    ... Genetic Testing (1 link) Genetic Testing Registry: Poland anomaly Other Diagnosis and Management Resources (3 links) Children's ... my area? Other Names for This Condition Poland anomaly Poland sequence Poland syndactyly Poland's anomaly Poland's syndrome ...

  19. 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)

  20. 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)

  1. [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.

  2. Genetics Home Reference: renal hypouricemia

    MedlinePlus

    ... Facebook Share on Twitter Your Guide to Understanding Genetic Conditions Search MENU Toggle navigation Home Page Search ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions renal hypouricemia renal hypouricemia Enable ...

  3. Genetics Home Reference: Friedreich ataxia

    MedlinePlus

    ... Facebook Share on Twitter Your Guide to Understanding Genetic Conditions Search MENU Toggle navigation Home Page Search ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions Friedreich ataxia Friedreich ataxia Enable ...

  4. Genetics Home Reference: craniometaphyseal dysplasia

    MedlinePlus

    ... Facebook Share on Twitter Your Guide to Understanding Genetic Conditions Search MENU Toggle navigation Home Page Search ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions craniometaphyseal dysplasia craniometaphyseal dysplasia Enable ...

  5. Genetics Home Reference: Sotos syndrome

    MedlinePlus

    ... Facebook Share on Twitter Your Guide to Understanding Genetic Conditions Search MENU Toggle navigation Home Page Search ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions Sotos syndrome Sotos syndrome Enable ...

  6. [Public health, genetics and ethics].

    PubMed

    Kottow, Miguel H

    2002-10-01

    Genetics research has shown enormous developments in recent decades, although as yet with only limited clinical application. Bioethical analysis has been unable to deal with the vast problems of genetics because emphasis has been put on the principlism applied to both clinical and research bioethics. Genetics nevertheless poses its most complex moral dilemmas at the public level, where a social brand of ethics ought to supersede the essentially interpersonal perspective of principlism. A more social understanding of ethics in genetics is required to unravel issues such as research and clinical explorations, ownership and patents, genetic manipulation, and allocation of resources. All these issues require reflection based on the requirements of citizenry, consideration of common assets, and definition of public policies in regulating genetic endeavors and protecting the society as a whole Bioethics has privileged the approach to individual ethical issues derived from genetic intervention, thereby neglecting the more salient aspects of genetics and social ethics.

  7. Genetics Home Reference: nonsyndromic holoprosencephaly

    MedlinePlus

    ... other types of holoprosencephaly caused by genetic syndromes, chromosome abnormalities, or substances that cause birth defects (teratogens). The ... Some people do not have apparent structural brain abnormalities but have some of the facial features ... deletion syndrome Genetic Testing Registry: Holoprosencephaly ...

  8. Education of nurses in genetics.

    PubMed Central

    Forsman, I

    1988-01-01

    The need for education of nurses in genetics was articulated more than 25 years ago. This article reviews the knowledge of practicing nurses about genetics as well as the content of genetics in nursing curricula. Implementation of federal legislation that mandated increased availability of genetic services and genetics education provided support for the examination of genetics content in curricula for health professionals, including nurses, and for the development of model programs to expand this content. Recent efforts to begin to develop a pool of nurse faculty who are well prepared in genetics will be described, as well as programs to provide the necessary content through continuing-education efforts. These efforts are expected to substantially improve the capability of nurses to contribute more effectively in the delivery of genetic services. PMID:3177390

  9. Synthetic biology and genetic causation.

    PubMed

    Oftedal, Gry; Parkkinen, Veli-Pekka

    2013-06-01

    Synthetic biology research is often described in terms of programming cells through the introduction of synthetic genes. Genetic material is seemingly attributed with a high level of causal responsibility. We discuss genetic causation in synthetic biology and distinguish three gene concepts differing in their assumptions of genetic control. We argue that synthetic biology generally employs a difference-making approach to establishing genetic causes, and that this approach does not commit to a specific notion of genetic program or genetic control. Still, we suggest that a strong program concept of genetic material can be used as a successful heuristic in certain areas of synthetic biology. Its application requires control of causal context, and may stand in need of a modular decomposition of the target system. We relate different modularity concepts to the discussion of genetic causation and point to possible advantages of and important limitations to seeking modularity in synthetic biology systems.

  10. 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) ...

  11. 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)

  12. 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.

  13. 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.

  14. 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)

  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 Other Diagnosis and Management Resources (2 ...

  16. Genetics Home Reference: atopic dermatitis

    MedlinePlus

    ... such as attention deficit hyperactivity disorder (ADHD) or depression. Related Information What does it mean if a disorder seems to run in my family? What is the prognosis of a genetic condition? Genetic and Rare Diseases Information Center Frequency ...

  17. Genetics Home Reference: bipolar disorder

    MedlinePlus

    ... 7 Genetic Testing Registry: Major affective disorder 8 Genetic Testing Registry: Major affective disorder 9 Other Diagnosis and Management Resources (5 links) Depression and Bipolar Support Alliance: Finding the Right Treatment ...

  18. Genetics Home Reference: Wolfram syndrome

    MedlinePlus

    ... are some genetic conditions more common in particular ethnic groups? Genetic Changes Mutations in the WFS1 gene cause ... and Bladder Control National Institute of Mental Health: Depression Educational Resources (12 links) Boston Children's Hospital: Hearing ...

  19. Genetics Home Reference: Parkinson disease

    MedlinePlus

    ... are some genetic conditions more common in particular ethnic groups? Genetic Changes Most cases of Parkinson disease probably ... Parkinson's disease: variation by age, gender, and race/ethnicity. Am J Epidemiol. 2003 Jun 1;157(11): ...

  20. Genetics Home Reference: proopiomelanocortin deficiency

    MedlinePlus

    ... links) Encyclopedia: ACTH Health Topic: Obesity Health Topic: Obesity in Children Genetic and Rare Diseases Information Center (1 link) ... Support and Advocacy Resources (4 links) Genetics of Obesity Study Healthy Children.org National Adrenal Diseases Foundation Obesity Action Coalition ...

  1. Genetics of Alzheimer's disease.

    PubMed

    Chouraki, Vincent; Seshadri, Sudha

    2014-01-01

    Alzheimer's disease (AD) represents the main form of dementia, and is a major public health problem. Despite intensive research efforts, current treatments have only marginal symptomatic benefits and there are no effective disease-modifying or preventive interventions. AD has a strong genetic component, so much research in AD has focused on identifying genetic causes and risk factors. This chapter will cover genetic discoveries in AD and their consequences in terms of improved knowledge regarding the disease and the identification of biomarkers and drug targets. First, we will discuss the study of the rare early-onset, autosomal dominant forms of AD that led to the discovery of mutations in three major genes, APP, PSEN1, and PSEN2. These discoveries have shaped our current understanding of the pathophysiology and natural history of AD as well as the development of therapeutic targets and the design of clinical trials. Then, we will explore linkage analysis and candidate gene approaches, which identified variants in Apolipoprotein E (APOE) as the major genetic risk factor for late-onset, "sporadic" forms of AD (LOAD), but failed to robustly identify other genetic risk factors, with the exception of variants in SORL1. The main focus of this chapter will be on recent genome-wide association studies that have successfully identified common genetic variations at over 20 loci associated with LOAD outside of the APOE locus. These loci are in or near-novel AD genes including BIN1, CR1, CLU, phosphatidylinositol-binding clathrin assembly protein (PICALM), CD33, EPHA1, MS4A4/MS4A6, ABCA7, CD2AP, SORL1, HLA-DRB5/DRB1, PTK2B, SLC24A4-RIN3, INPP5D, MEF2C, NME8, ZCWPW1, CELF1, FERMT2, CASS4, and TRIP4 and each has small effects on risk of AD (relative risks of 1.1-1.3). Finally, we will touch upon the ongoing effort to identify less frequent and rare variants through whole exome and whole genome sequencing. This effort has identified two novel genes, TREM2 and PLD3, and shown a

  2. Genetic Counseling in Military Hospitals

    DTIC Science & Technology

    1987-04-01

    maintain an action for negligent prenatal care provided to the plaintiff’s mother while the mother and father were on active duty in the Air Force. The court...military physicians have generally met the standards of care for genetic counseling, but increased funding for personnel and equipment is necessary for...20 IV. LEGAL ISSUES IN GENETIC COUNSELING ............... 25 A. Standard of Care in Genetic Counseling ............... 25 B. Genetic Counseling

  3. 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…

  4. 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)

  5. 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.

  6. Genetics in Relation to Biology.

    ERIC Educational Resources Information Center

    Stewart, J. Bird

    1987-01-01

    Claims that most instruction dealing with genetics is limited to sex education and personal hygiene. Suggests that the biology curriculum should begin to deal with other issues related to genetics, including genetic normality, prenatal diagnoses, race, and intelligence. Predicts these topics will begin to appear in British examination programs.…

  7. Joining forces for genetic conservation

    Treesearch

    Gary Man; Emily Boes; Rhoda Maurer; Michael Dosmann; Matt Lobdell; Kevin Conrad; Mike Kintgen; Rebecca Sucher; Martin Nicholson; David Stevenson; Brianna McTeague; Evan Heck; Richard A. Sniezko

    2017-01-01

    Facing a Challenge Non-native diseases and insects as well as a changing climate pose serious threats to native trees in North America. Genetic variation in a species is key to its enduring persistence in the face of these abiotic and biotic threats. Efforts to conserve genetic diversity of North American tree at-risk species will ensure the genetic...

  8. Genetics of Sesame Street Characters.

    ERIC Educational Resources Information Center

    Raye, Susan

    2001-01-01

    Teaches genetics and inheritance using the characters from Sesame Street. Asks students to create a gene map of their favorite character and determine those genes passing to the next generation. Includes a genetics activity sheet and genetic information on the characters. (YDS)

  9. [Brazilian criminal law and genetics].

    PubMed

    de Souza, P V

    1999-01-01

    This article analyses the Brasilia criminal regulation on genetic. Act No. 8.974/95 is examined because it regulates some criminal typologies on genetic engineering and assisted reproduction. Moreover, it presents information about the Act Project No. 149/97, on genetic discrimination.

  10. 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)

  11. Genetics of Sesame Street Characters.

    ERIC Educational Resources Information Center

    Raye, Susan

    2001-01-01

    Teaches genetics and inheritance using the characters from Sesame Street. Asks students to create a gene map of their favorite character and determine those genes passing to the next generation. Includes a genetics activity sheet and genetic information on the characters. (YDS)

  12. Where genetic algorithms excel.

    PubMed

    Baum, E B; Boneh, D; Garrett, C

    2001-01-01

    We analyze the performance of a genetic algorithm (GA) we call Culling, and a variety of other algorithms, on a problem we refer to as the Additive Search Problem (ASP). We show that the problem of learning the Ising perceptron is reducible to a noisy version of ASP. Noisy ASP is the first problem we are aware of where a genetic-type algorithm bests all known competitors. We generalize ASP to k-ASP to study whether GAs will achieve "implicit parallelism" in a problem with many more schemata. GAs fail to achieve this implicit parallelism, but we describe an algorithm we call Explicitly Parallel Search that succeeds. We also compute the optimal culling point for selective breeding, which turns out to be independent of the fitness function or the population distribution. We also analyze a mean field theoretic algorithm performing similarly to Culling on many problems. These results provide insight into when and how GAs can beat competing methods.

  13. 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.

  14. Genetics of impulsive behaviour.

    PubMed

    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.

  15. Genetics of adult glioma.

    PubMed

    Goodenberger, McKinsey L; Jenkins, Robert B

    2012-12-01

    Gliomas make up approximately 30% of all brain and central nervous system tumors and 80% of all malignant brain tumors. Despite the frequency of gliomas, the etiology of these tumors remains largely unknown. Diffuse gliomas, including astrocytomas and oligodendrogliomas, belong to a single pathologic class but have very different histologies and molecular etiologies. Recent genomic studies have identified separate molecular subtypes within the glioma classification that appear to correlate with biological etiology, prognosis, and response to therapy. The discovery of these subtypes suggests that molecular genetic tests are and will be useful, beyond classical histology, for the clinical classification of gliomas. While a familial susceptibility to glioma has been identified, only a small percentage of gliomas are thought to be due to single-gene hereditary cancer syndromes. Through the use of linkage studies and genome-wide association studies, multiple germline variants have been identified that are beginning to define the genetic susceptibility to glioma.

  16. 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.

  17. Genetics of osteoporosis.

    PubMed

    Jin, Huilin; Ralston, Stuart H

    2005-03-01

    Genetic factors play an important role in regulating bone mineral density and other phenotypes relevant to the pathogenesis of osteoporosis such as ultrasound properties of bone, skeletal geometry, and bone turnover. Progress has been made in identifying quantitative traits for regulation of bone mineral density by linkage studies in man and mouse, but relatively few causal genes have been identified. Dramatic progress has been made in identifying the genes responsible for monogenic bone diseases and it appears that polymorphisms in many of these genes also play a role in regulating bone mineral density in the general population. Advances in knowledge about the genetic basis of osteoporosis and other bone diseases offer the prospect of developing new markers for assessment of fracture risk and the identification of novel molecular targets for the design of new drug treatments for osteoporosis.

  18. "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.

  19. Ethics, genetics and pediatrics.

    PubMed

    Souza, Ricardo Timm de; Goldim, José Roberto

    2008-08-01

    To reflect on the nature of ethics, from a contemporary perspective, and also on which features of the family relationship have an impact on the interface between genetics and pediatrics. The data used are the fruit of the authors' own intellectual production plus other bibliographic references. Genetics has presented ethics with new challenges. Particularly in pediatrics, where caring for patients is almost indivisible from a continuous relationship with their families, these issues are amplified even further, generating new questions that health professionals have not previously had to face. Based on the reflections outlined here, emphasis can be placed on the importance of actively recognizing the Other in its multiple dimensions and on the repercussions that this perspective has for the physician-patient-family relationship.

  20. Excess genetic baggage dumped

    SciTech Connect

    Moffat, A.S.

    1991-12-06

    In recent years, putting new genes into plants has become routine, as plant scientists have genetically engineered a wide variety of plant strains having novel genes that help them resists pests and disease, improve their nutritional properties, and produce drugs and industrial enzymes. Not widely appreciated, however, is the fact that all those genes have been introduced into the plants in combination with so-called marker genes, usually encoding for antibiotic or herbicide resistance, that are used as laboratory tools to select the few plants that have acquired the novel genes from the many that have not. The genetic engineers had previously been unable to remove the marker genes, but now scientists have come up with a new version of the gene transfer procedure that allows the marker genes to be expunged after plants have acquired the desired genes.

  1. 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

  2. The expanded genetic alphabet.

    PubMed

    Malyshev, Denis A; Romesberg, Floyd E

    2015-10-05

    All biological information, since the last common ancestor of all life on Earth, has been encoded by a genetic alphabet consisting of only four nucleotides that form two base pairs. Long-standing efforts to develop two synthetic nucleotides that form a third, unnatural base pair (UBP) have recently yielded three promising candidates, one based on alternative hydrogen bonding, and two based on hydrophobic and packing forces. All three of these UBPs are replicated and transcribed with remarkable efficiency and fidelity, and the latter two thus demonstrate that hydrogen bonding is not unique in its ability to underlie the storage and retrieval of genetic information. This Review highlights these recent developments as well as the applications enabled by the UBPs, including the expansion of the evolution process to include new functionality and the creation of semi-synthetic life that stores increased information.

  3. Genetic Transformation in Citrus

    PubMed Central

    Donmez, Dicle; Simsek, Ozhan; Izgu, Tolga; Aka Kacar, Yildiz; Yalcin Mendi, Yesim

    2013-01-01

    Citrus is one of the world's important fruit crops. Recently, citrus molecular genetics and biotechnology work have been accelerated in the world. Genetic transformation, a biotechnological tool, allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. Citrus transformation has now been achieved in a number of laboratories by various methods. Agrobacterium tumefaciens is used mainly in citrus transformation studies. Particle bombardment, electroporation, A. rhizogenes, and a new method called RNA interference are used in citrus transformation studies in addition to A. tumefaciens. In this review, we illustrate how different gene transformation methods can be employed in different citrus species. PMID:23983635

  4. 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.

  5. 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.

  6. Referring patients for a medical genetics consultation and genetic counseling.

    PubMed

    Sutton, Reid

    2011-01-01

    Clinical geneticists and genetic counselors provide diagnosis and counseling for genetic disorders affecting every organ system and every age group. Genetic counselors are more focused on informing patients and families about the inheritance of a genetic disorder and providing recurrence risk counseling, support and information about a diagnosis and reproductive options. Medical geneticists may also share some of these roles in addition to establishing a diagnosis and providing medical management. Medical Geneticists receive training in ACGME-accredited residency programs and are certified by the American Board of Medical Genetics. Genetic counseling is a masters degree program and certification is granted by the American Board of Genetic Counseling. When a patient/family is referred to a Clinical Geneticist, they may expect a thorough evaluation in an effort to establish a diagnosis that may provide information about etiology, prognosis, therapy and recurrence risk. Copyright © 2011 S. Karger AG, Basel.

  7. Genetics of pancreatitis: an update for clinicians and genetic counselors.

    PubMed

    Solomon, Sheila; Whitcomb, David C

    2012-04-01

    With novel genetic technologies available, there is a paradigm shift in the way that risk assessments, diagnoses,and therapies for genetic susceptibility syndromes are addressed. Hereditary pancreatitis is among these conditions, for which genetic counseling and next generation sequencing, help families better understand, cope with and live healthier lives. Identifying a genetic etiology to a condition formally believed to be solely environmentally induced can alter the path for treatment for many patients. This finding introduces the concept of gene-environment interactions in human disease and the relationship between genetic predisposition and exposure risk in disease development. The genetic counseling process is complex with medical explanations, psychosocial issues relating to coping with diagnosis, potential future health problems, recurrence risks and family planning. These sometimes difficult conversations can be facilitated by a genetic counselor as a member of the multidisciplinary team. This chapter addresses the intricate medical and psychosocial issues that can arise in the setting of treating patients with hereditary pancreatitis.

  8. An experimental evaluation of host specificity: The role of encounter and compatibility filters for a rhizocephalan parasite of crabs

    USGS Publications Warehouse

    Kuris, Armand M.; Goddard, Jeffrey H. R.; Torchin, Mark E.; Murphy, Nicole; Gurney, Robert; Lafferty, Kevin D.

    2007-01-01

    The encounter/compatibility paradigm of host specificity provides three qualitative pathways to the success or failure of a potential host-parasite interaction. It is usually impossible to distinguish between two of these (encounter and compatibility filters closed versus encounter filter open and compatibility filter closed) because unsuccessful infection attempts are difficult to observe in nature. We were able to open the encounter filter under experimental laboratory conditions. Our analytical system used the rhizocephalan barnacle, Sacculina carcini, a parasitic castrator of the European green crab, Carcinus maenas, and Pachygrapsus marmoratus, a native European crab that occurs with C. maenas but is not parasitized by S. carcini in nature. Penetration followed by unsuccessful infection of P. marmoratus crabs by parasitic barnacle larvae leaves a uniquely permanent record in the thoracic ganglion of the crabs. This provided us with a novel tool to quantify the encounter filter in a host-parasite system in nature. We demonstrated, in the laboratory, that the compatibility filter was closed and that, in nature, even where barnacle larvae were present, the encounter filter was also effectively closed. The closure of both filters in nature explains the failure of this potential host-parasite interaction, an outcome favored by selection in both host and parasite.

  9. Oceanographic and behavioural processes affecting invertebrate larval dispersal and supply in the western Iberia upwelling ecosystem

    NASA Astrophysics Data System (ADS)

    Queiroga, Henrique; Cruz, Teresa; dos Santos, Antonina; Dubert, Jesus; González-Gordillo, Juan Ignácio; Paula, José; Peliz, Álvaro; Santos, A. Miguel P.

    2007-08-01

    The present review addresses recent findings made in the western Iberia ecosystem on the behavioural and physical interactions that regulate dispersal, supply to coastal habitats and settlement of invertebrate larvae. These studies used the barnacle Chthamalus spp. and the crab Carcinus maenas as model organisms. The observations made on the Iberian shelf showed extensive diel vertical migrations along the water column by representatives of both groups that have never been reported before. The interaction of the diel vertical migration with the two-layer flow structure of upwelling/downwelling circulation suggests a mechanism that may help to retain larvae in shelf waters during upwelling conditions. Measurements of daily supply of C. maenas megalopae to estuaries separated by 500 km disclosed a semilunar pattern, with highest supply around highest amplitude tides, indicating that supply of megalopae to estuaries is accomplished by selective tidal stream transport. Relaxation of equatorward winds also played a role in supply, by enhancing translocation of megalopae to the nearshore. Concerning Chthamalus larvae, the observations on daily settlement made at rocky shores also separated by 500 km showed unclear patterns between locations and years. The relationship of settlement with water temperature, tidal range and upwelling indices indicated that supply of barnacle cyprids may be controlled by multiple mechanisms, viz. upwelling/downwelling circulation, internal tidal bores and sea breezes.

  10. The Bacterial (Vibrio alginolyticus) Production of Tetrodotoxin in the Ribbon Worm Lineus longissimus—Just a False Positive?

    PubMed Central

    Strand, Malin; Hedström, Martin; Seth, Henrik; McEvoy, Eric G.; Jacobsson, Erik; Göransson, Ulf; Andersson, Håkan S.; Sundberg, Per

    2016-01-01

    We test previous claims that the bacteria Vibrio alginolyticus produces tetrodotoxin (TTX) when living in symbiosis with the nemertean Lineus longissimus by a setup with bacteria cultivation for TTX production. Toxicity experiments on the shore crab, Carcinus maenas, demonstrated the presence of a paralytic toxin, but evidence from LC-MS and electrophysiological measurements of voltage-gated sodium channel–dependent nerve conductance in male Wistar rat tissue showed conclusively that this effect did not originate from TTX. However, a compound of similar molecular weight was found, albeit apparently non-toxic, and with different LC retention time and MS/MS fragmentation pattern than those of TTX. We conclude that C. maenas paralysis and death likely emanate from a compound <5 kDa, and via a different mechanism of action than that of TTX. The similarity in mass between TTX and the Vibrio-produced low-molecular-weight, non-toxic compound invokes that thorough analysis is required when assessing TTX production. Based on our findings, we suggest that re-examination of some published claims of TTX production may be warranted. PMID:27023570

  11. The Bacterial (Vibrio alginolyticus) Production of Tetrodotoxin in the Ribbon Worm Lineus longissimus-Just a False Positive?

    PubMed

    Strand, Malin; Hedström, Martin; Seth, Henrik; McEvoy, Eric G; Jacobsson, Erik; Göransson, Ulf; Andersson, Håkan S; Sundberg, Per

    2016-03-25

    We test previous claims that the bacteria Vibrio alginolyticus produces tetrodotoxin (TTX) when living in symbiosis with the nemertean Lineus longissimus by a setup with bacteria cultivation for TTX production. Toxicity experiments on the shore crab, Carcinus maenas, demonstrated the presence of a paralytic toxin, but evidence from LC-MS and electrophysiological measurements of voltage-gated sodium channel-dependent nerve conductance in male Wistar rat tissue showed conclusively that this effect did not originate from TTX. However, a compound of similar molecular weight was found, albeit apparently non-toxic, and with different LC retention time and MS/MS fragmentation pattern than those of TTX. We conclude that C. maenas paralysis and death likely emanate from a compound <5 kDa, and via a different mechanism of action than that of TTX. The similarity in mass between TTX and the Vibrio-produced low-molecular-weight, non-toxic compound invokes that thorough analysis is required when assessing TTX production. Based on our findings, we suggest that re-examination of some published claims of TTX production may be warranted.

  12. Disturbance of a met-enkephalin-like hormone in the hepatopancreas of crabs contaminated by metals

    SciTech Connect

    Amiard-Triquet, C.; Amiard, J.C.; Ferrand, R.; Andersen, A.C.; Dubois, M.P.

    1986-04-01

    This study combines trace-metal analysis with an immunofluorescent detection of a methionine-enkephalin-like substance in the digestive gland of the shore crab, Carcinus maenas L. The crabs were taken from two sites: Saint Nazaire and Le Croisic, the first being polluted in comparison to the second. The experimental crabs were also taken in Le Croisic and contaminated with Cd, Pb, Cu, and Zn during 1 to 3 weeks in the laboratory. The immunohistological observations indicate a change in the localization of the immunofluorescent methionine-enkephalin-like substance in the cells of the tubules constituting the digestive gland. In crabs from the clean site, experimentally starved or not, the immunofluorescence appears mostly basal while it exhibits an apical localization in metal-contaminated crabs or crabs caught in the polluted area. The detected substance, the nature of which remains unknown, accompanies cytoplasmic secretory granules during their migration to the cellular apex preceding the apocrine secretion. This change of the immunoreactivity enables the detection of metal contamination but it is nonspecific and therefore, a general environment pollution could produce the same phenomenon. In the particular case of zinc, this alteration appears at a Zn concentration in seawater which does not disturb the natural level of this essential metal in the digestive gland of C. maenas.

  13. [Hereditary deafness: molecular genetics].

    PubMed

    Hardelin, Jean-Pierre; Denoyelle, Françoise; Levilliers, Jacqueline; Simmler, Marie-Christine; Petit, Christine

    2004-03-01

    This article outlines recent advances in explaining hereditary deafness in molecular terms, focusing on isolated (i.e. nonsyndromic) hearing loss. The number of genes identified (36 to date) is growing rapidly. However, difficulties inherent in genetic linkage analysis, coupled with the possible involvement of environmental causes, have so far prevented the characterization of the main genes causative or predisposing to the late-onset forms of deafness.

  14. Tree genetics and improvement

    SciTech Connect

    Bey, C.F.; Houston, D.B.; Dinus, R.J.

    1986-01-01

    Tree improvement is a complex science and a multifaceted art. Tree improvement is most valuable when integrated within land-management programs. Major efforts are currently geared to developing improved seed for reforestation programs. Progeny testing is now a routine part of tree-improvement programs. Topics such as advanced-generation breeding, shortened generations, resistance breeding, and control of cone and seed insects are being given priority. Activity continues in basic research, involving genetic engineering, tissue culture, and population theory.

  15. Genetics of Diabetes Insipidus.

    PubMed

    Schernthaner-Reiter, Marie Helene; Stratakis, Constantine A; Luger, Anton

    2017-06-01

    Diabetes insipidus is a disease characterized by polyuria and polydipsia due to inadequate release of arginine vasopressin from the posterior pituitary gland (neurohypophyseal diabetes insipidus) or due to arginine vasopressin insensitivity by the renal distal tubule, leading to a deficiency in tubular water reabsorption (nephrogenic diabetes insipidus). This article reviews the genetics of diabetes insipidus in the context of its diagnosis, clinical presentation, and therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Genetics of inherited cardiomyopathy.

    PubMed

    Jacoby, Daniel; McKenna, William J

    2012-02-01

    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.

  17. 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.

  18. Genetic influences on sarcoidosis.

    PubMed

    Ishihara, M; Ohno, S

    1997-01-01

    To investigate the genetic influences underlying the development of sarcoidosis, HLA class II genotyping was performed in Japanese patients with sarcoidosis and healthy controls using the PCR-RFLP method. The frequencies of both DR52 group antigen-associated alleles (HLA-DRB1*11, -DRB1*12 and -DRB1*14) and DRB1*08 alleles were higher in the patient group, suggesting that the common, specific amino acid residue on the DRB1 molecule of these alleles may determine susceptibility to sarcoidosis. Alternatively, it is possible that another susceptibility gene, linked to these DRB1 alleles, exists within the MHC region. We screened the TNFA, TNFB, HSP70-1 and Hum70t genes around the class III region, as well as the HLA-DMA and -DMB genes in the class II region, for genetic polymorphism in sarcoidosis. None of these genes suggested a susceptibility to sarcoidosis. These studies support the thesis that one of the major genetic factors controlling the development of sarcoidosis is located within the DRB1 locus in the HLA class II region.

  19. 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.

  20. Genetic Manipulations in Dermatophytes.

    PubMed

    Alshahni, Mohamed Mahdi; Yamada, Tsuyoshi

    2017-02-01

    Dermatophytes are a group of closely related fungi that nourish on keratinized materials for their survival. They infect stratum corneum, nails, and hair of human and animals, accounting the largest portion of fungi causing superficial mycoses. Huge populations are suffering from dermatophytoses, though the biology of these fungi is largely unknown yet. Reasons are partially attributed to the poor amenability of dermatophytes to genetic manipulation. However, advancements in this field over the last decade made it possible to conduct genetic studies to satisfying extents. These included genetic transformation methods, indispensable molecular tools, i.e., dominant selectable markers, inducible promoter, and marker recycling system, along with improving homologous recombination frequency and gene silencing. Furthermore, annotated genome sequences of several dermatophytic species have recently been available, ensuring an optimal recruitment of the molecular tools to expand our knowledge on these fungi. In conclusion, the establishment of basic molecular tools and the availability of genomic data will open a new era that might change our understanding on the biology and pathogenicity of this fungal group.

  1. Genetics and violence.

    PubMed

    Alsobrook, J P; Pauls, D L

    2000-10-01

    As is evident from this brief review, the genetic study of violence is maturing at an ever-increasing rate; much more work is needed to examine specific molecular genetic markers and their associated phenotypes, particularly in subjects with juvenile onset. It is also becoming clear that more work is needed to help delineate the specific phenotypes that are being transmitted within families. It is unlikely that we will find a gene or genes that are both necessary and sufficient for the manifestation of aggression and violence. It is more likely that specific genes will be associated with discrete factors that either increase the risk for the expression of violence or that are components of the violent phenotype. Thus, in addition to continuing research that examines the role of specific genetic factors in the manifestation of violence, more work is needed that will help further develop the nosology of violence and related behaviors. As noted previously, an understanding of the inherited phenotype is critical in the study of any disorder. It is especially important in the study of complex behaviors such as violence in which there may be several behavioral components that comprise the complete diagnostic category.

  2. Cellular genetic therapy.

    PubMed

    Del Vecchio, F; Filareto, A; Spitalieri, P; Sangiuolo, F; Novelli, G

    2005-01-01

    Cellular genetic therapy is the ultimate frontier for those pathologies that are consequent to a specific nonfunctional cellular type. A viable cure for there kinds of diseases is the replacement of sick cells with healthy ones, which can be obtained from the same patient or a different donor. In fact, structures can be corrected and strengthened with the introduction of undifferentiated cells within specific target tissues, where they will specialize into the desired cellular types. Furthermore, consequent to the recent results obtained with the transdifferentiation experiments, a process that allows the in vitro differentiation of embryonic and adult stem cells, it has also became clear that many advantages may be obtained from the use of stem cells to produce drugs, vaccines, and therapeutic molecules. Since stem cells can sustain lineage potentials, the capacity for differentiation, and better tolerance for the introduction of exogenous genes, they are also considered as feasible therapeutic vehicles for gene therapy. In fact, it is strongly believed that the combination of cellular genetic and gene therapy approaches will definitely allow the development of new therapeutic strategies as well as the production of totipotent cell lines to be used as experimental models for the cure of genetic disorders.

  3. Genetic immunotherapy for cancer.

    PubMed

    Ribas, A; Butterfield, L H; Economou, J S

    2000-01-01

    Genetic immunization refers to treatment strategies where gene transfer methods are used to generate immune responses against cancer. Our growing knowledge of the mechanisms regulating the initiation and maintenance of cytotoxic immune responses has provided the rationale for the design of several genetic immunization strategies. Tumor cells have been gene-modified to express immune stimulatory genes and are then administered as tumor vaccines, in an attempt to overcome tumor cell ignorance by the immune system. With the description of well-characterized tumor antigens, multiple strategies have been proposed mainly aimed at optimal tumor antigen presentation by antigen-presenting cells (APC). Among APC, the dendritic cells have been recognized as the most powerful cells in this class, and have become the target for introducing tumor antigen genes to initiate antitumor immune responses. The detailed knowledge of how the immune system can be activated to specifically recognize tumor antigens, and the mechanisms involved in the control of this immune response, provide the basis for modern genetic immunization strategies for cancer treatment.

  4. Genetics of thyroid function.

    PubMed

    Medici, Marco; Visser, Theo J; Peeters, Robin P

    2017-03-01

    Recent studies show that subtle variations in thyroid function, including subclinical thyroid dysfunction, and even variation in thyroid function within the normal range, are associated with morbidity and mortality. It is estimated that 40-65% of the inter-individual variation in serum TSH and FT4 levels is determined by genetic factors. To identify these factors, various linkage and candidate gene studies have been performed in the past, which have identified only a few genes. In the last decade, genome-wide association studies identified many new genes, while recent whole-genome sequencing efforts have also been proven to be effective. In the current review, we provide a systematic overview of these studies, including strengths and limitations. We discuss new techniques which will further clarify the genetic basis of thyroid function in the near future, as well as the potential use of these genetic markers in personalizing the management of thyroid disease patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. 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

  6. 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

  7. Darwin and genetics.

    PubMed

    Charlesworth, Brian; Charlesworth, Deborah

    2009-11-01

    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.

  8. [Genetics of osteoporosis].

    PubMed

    Cohen-Solal, M; de Vernejoul, M C

    2004-12-01

    Osteoporosis is a multifactorial disease involving genetic component and several environmental factors. Some rare diseases that are associated with osteoporosis such as Lobstein disease or the "pseudoglial osteoporosis" syndrom are monogenetic. Nevertheless common osteoporosis is a polygenic affection resulting from the interaction between the polymorphism of different genes and the environmental factors. The genetic component of osteoporosis encompasses roughly 60 to 70% of bone mineral density, whereas the effect on fracture risk seems lower because of the importance of other environmental factors as falls. Many polymorphisms of candidate genes involved in the regulation of bone mass have been correlated to bone density. It is likely that many genes participate to the regulation of bone density although the existence of a major gene is highly suspected. Moreover linkage analysis after genome-wide search in populations with severe osteoporosis has focused on some regions of interest (QTL) on the chromosomes. This will allow to localize one or more specific genes. The current genetic studies on different populations affected by osteoporosis or not will be useful in order to better predict the fracture risk in association with bone density and biochemical markers of bone turnover. Moreover, this will lead to the development of new treatments of osfeoporosis and will help to adapt the therapy for individual patients.

  9. Advances in osteoarthritis genetics.

    PubMed

    Panoutsopoulou, Kalliope; Zeggini, Eleftheria

    2013-11-01

    Osteoarthritis (OA), the most common form of arthritis, is a highly debilitating disease of the joints and can lead to severe pain and disability. There is no cure for OA. Current treatments often fail to alleviate its symptoms leading to an increased demand for joint replacement surgery. Previous epidemiological and genetic research has established that OA is a multifactorial disease with both environmental and genetic components. Over the past 6 years, a candidate gene study and several genome-wide association scans (GWAS) in populations of Asian and European descent have collectively established 15 loci associated with knee or hip OA that have been replicated with genome-wide significance, shedding some light on the aetiogenesis of the disease. All OA associated variants to date are common in frequency and appear to confer moderate to small effect sizes. Some of the associated variants are found within or near genes with clear roles in OA pathogenesis, whereas others point to unsuspected, less characterised pathways. These studies have also provided further evidence in support of the existence of ethnic, sex, and joint specific effects in OA and have highlighted the importance of expanded and more homogeneous phenotype definitions in genetic studies of OA.

  10. Genetics of Alzheimer's disease.

    PubMed

    Alonso Vilatela, María Elisa; López-López, Marisol; Yescas-Gómez, Petra

    2012-11-01

    Alzheimer's disease (AD) is the most frequent cause of dementia in the elderly and represents an important and increasing clinical challenge in terms of diagnosis and treatment. This review highlights the role of genetics in understanding the pieces of the complex AD puzzle and summarizes the genes known to be involved in Alzheimer's disease. The amount of risk of Alzheimer's disease that is attributable to genetics is estimated to be ∼70%. Mutations in the genes encoding amyloid precursor protein (APP), presenilin 1 (PSEN1) and presenilin 2 (PSEN2) are responsible for early-onset autosomal dominant AD. Although mutations in these genes account for ∼1% of AD cases, their identification has been crucial to understand the molecular mechanisms of AD. For the more common complex late-onset AD, the ɛ-4 allele of the gene encoding apolipoprotein E (APOE) has been recognized as a major genetic risk factor. More recently, several potential disease risk genes have been identified with the use of advanced genomic methods like genome-wide association studies (GWAS). In the end, the knowledge of the pathophysiological mechanisms leading to AD will enable the development of more accurate diagnostic tests and new disease-treating strategies. Copyright © 2012 IMSS. Published by Elsevier Inc. All rights reserved.

  11. Genetic landscape of meningioma.

    PubMed

    Yuzawa, Sayaka; Nishihara, Hiroshi; Tanaka, Shinya

    2016-10-01

    Meningioma is the most common intracranial tumor, arising from arachnoid cells of the meninges. Monosomy 22 and inactivating mutations of NF2 are well-known genetic alterations of meningiomas. More recently, mutations in TRAF7, AKT1, KLF4, SMO, and PIK3CA were identified by next-generation sequencing. We here reviewed 553 meningiomas for the mutational patterns of the six genes. NF2 aberration was observed in 55 % of meningiomas. Mutations of TRAF7, AKT1, KLF4, PIK3CA, and SMO were identified in 20, 9, 9, 4.5, and 3 % of cases, respectively. Altogether, 80 % of cases harbored at least one of the genetic alterations in these genes. NF2 alterations and mutations of the other genes were mutually exclusive with a few exceptions. Clinicopathologically, tumors with mutations in TRAF7/AKT1 and SMO shared specific features: they were located in the anterior fossa, median middle fossa, or anterior calvarium, and most of them were meningothelial or transitional meningiomas. TRAF7/KLF4 type meningiomas showed different characteristics in that they occurred in the lateral middle fossa and median posterior fossa as well as anterior fossa and median middle fossa, and contained a secretory meningioma component. We also discuss the mutational hotspots of these genes and other genetic/cytogenetic alterations contributing to tumorigenesis or progression of meningiomas.

  12. Reprogenetics: Preimplantational genetics diagnosis

    PubMed Central

    Coco, Roberto

    2014-01-01

    Preimplantational Genetics Diagnosis (PGD) is requested by geneticists and reproductive specialists. Usually geneticists ask for PGD because one or both members of the couple have an increased genetic risk for having an affected offspring. On the other hand, reproductive specialists ask for embryo aneuploidy screening (PGS) to assures an euploid embryo transfer, with the purpose to achieve an ongoing pregnancy, although the couple have normal karyotypes. As embryonic aneuploidies are responsible for pre and post implantation abortions, it is logical to considerer that the screening of the embryonic aneuploidies prior to embryo transfer could improve the efficiency of the in vitro fertilization procedures. Nevertheless, it is still premature to affirm this until well-designed clinical trials were done, especially in women of advanced age where the rate of embryos with aneuploidies is much greater. Although the indications of PGD are similar to conventional prenatal diagnosis (PND), PGD has less ethical objections than the PND. As with the PGD/PGS results only unaffected embryos are transferred, both methods can avoid the decision to interrupt the pregnancy due to a genetic problem; this makes an important difference when compared to conventional prenatal diagnosis. PMID:24764761

  13. Reprogenetics: Preimplantational genetics diagnosis.

    PubMed

    Coco, Roberto

    2014-03-01

    Preimplantational Genetics Diagnosis (PGD) is requested by geneticists and reproductive specialists. Usually geneticists ask for PGD because one or both members of the couple have an increased genetic risk for having an affected offspring. On the other hand, reproductive specialists ask for embryo aneuploidy screening (PGS) to assures an euploid embryo transfer, with the purpose to achieve an ongoing pregnancy, although the couple have normal karyotypes. As embryonic aneuploidies are responsible for pre and post implantation abortions, it is logical to considerer that the screening of the embryonic aneuploidies prior to embryo transfer could improve the efficiency of the in vitro fertilization procedures. Nevertheless, it is still premature to affirm this until well-designed clinical trials were done, especially in women of advanced age where the rate of embryos with aneuploidies is much greater. Although the indications of PGD are similar to conventional prenatal diagnosis (PND), PGD has less ethical objections than the PND. As with the PGD/PGS results only unaffected embryos are transferred, both methods can avoid the decision to interrupt the pregnancy due to a genetic problem; this makes an important difference when compared to conventional prenatal diagnosis.

  14. Genetically-encoded Reporters

    NASA Astrophysics Data System (ADS)

    Isacoff, Ehud

    2002-03-01

    One of the principle goals of neuroscience has been to understand the cellular basis of information processing and the plasticity that underlies learning and memory. Efforts in this area have mainly relied on electrical recording and optical imaging with chemical dyes. Over the last few years we and others have begun to develop genetically-encoded optical reporter "dyes" which should provide several important advantages over the classical methods for monitoring signal transmission in the nervous system. The advantages are that genetically-encoded reporters can be molecularly targeted a) to specific cell types via cell-specific promoters, and b) to specific subcellular compartments by peptides that are recognized by the protein sorting machinery of the cell. This makes it possible, in principle, to exclude signals from non-neuronal cells and to visualize selectively, in a brain region that contains many cell types with numerous kinds of synaptic connections, the activity of specific types of neurons (e.g. GABAergic interneurons) and specific synaptic elements (e.g. nerve terminals or dendrites), something that has hitherto not been possible. An additional advantage is that protein reporters may be rationally and irrationally "tuned" with mutations in functional domains known to control their dynamic range of operation. The general idea behind genetically-encoded reporters of cell signaling is to encode a protein that is either intrinsically fluorescent, or that can be labeled orthogonally with a fluorescent probe, and where the physiological signal changes fluorescence emission. I will describe recent progress employing both kinds of approaches.

  15. 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

  16. 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

  17. Genetic selection of boars.

    PubMed

    Safranski, T J

    2008-11-01

    Selection of boars by visual appraisal is the simplest and oldest method used by the swine industry. However, individual performance testing, and later use of computers to incorporate relatives' data and account for environmental variation, resulted in greater rate of improvement for economically important traits. Examples of molecular genetic tools that have increased improvement for some traits are also discussed. Accurate identification of genetic merit is increasingly important with widespread use of AI and resultant greater progeny number per sire. Historically, selection was to produce desirable progeny; however, with the majority of boars now housed in dedicated boar facilities, and the efficiency of sperm production being recorded, boar stud personnel are increasingly interested in selection of boars for fertility traits. Selecting boars that are lean and heavily muscled and have good semen parameters may be problematic, given the genetic relationships among the traits. Whereas conventional animal breeding methods will remain important, use of molecular tools will increase, and identification of a boar's fertility potential at birth will allow earlier and more efficient selection of high-fertility boars. Ability to achieve acceptable female reproduction with frozen semen would facilitate selection for longevity. However, this would lengthen the generation interval and could dilute selection intensity for other traits, as it requires indirect selection for semen freezability.

  18. Genetics and social class

    PubMed Central

    Holtzman, N

    2002-01-01

    Design: Using genetic epidemiological principles, five claims on the role of genes in determining social class are examined: (1) traits that run in families are usually inherited; (2) complex traits can be explained by alleles at a single gene locus; (3) complex traits are transmitted intact from one generation to the next; (4) natural selection explains social advantage. (5) Heritability estimates provide a valid estimate of the importance of genes in explaining complex human traits or behaviour. Results: (1) Traits that run in families can result from environmental exposures that differ by social class. (2) The protein encoded by any single gene has too narrow a range of biological activity to explain traits as complex as social status. (3) Because alleles at different gene loci are transmitted independently, genetic inheritance cannot explain why offspring display the same complex traits as their parents. (4) The propagation of mutations that might result in a selective advantage takes much longer than the time for which any social class has achieved or maintained dominance. (5) Heritability measures are accurate only when environment is maintained constant. This is impossible in evaluating human traits. Conclusions: The roots of social class differences do not lie in our genes. Consequently, genetics cannot be used as a justification for maintaining a ruling class, limiting procreation among the poor, or minimising social support programmes. PMID:12080161

  19. 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.

  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. Influence of oxygen partial pressures on protein synthesis in feeding crabs.

    PubMed

    Mente, Eleni; Legeay, Alexia; Houlihan, Dominic F; Massabuau, Jean-Charles

    2003-02-01

    Many water-breathing animals have a strategy that consists of maintaining low blood PO2 values in a large range of water oxygenation level (4-40 kPa). This study examines the postprandial changes in O2 consumption, arterial blood PO2, and tissue protein synthesis in the shore crab Carcinus maenas in normoxic, O2-depleted, and O2-enriched waters to study the effects of this strategy on the O2 consumption and peptide bond formation after feeding. In normoxic water (21 kPa), the arterial PO2 was 1.1 kPa before feeding and 1.2 kPa 24 h later. In water with a PO2 of 3 kPa (arterial PO2 0.6 kPa), postprandial stimulation of protein synthesis and O2 consumption were blocked. The blockade was partial at a water PO2 of 4 kPa (arterial PO2 0.8 kPa). An increase in environmental PO2 (60 kPa, arterial PO2 10 kPa) resulted in an increase in protein synthesis compared with normoxic rates. It is concluded that the arterial PO2 spontaneously set in normoxic Carcinus limits the rates of protein synthesis. The rationale for such a strategy is discussed.

  2. 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 ...

  3. Assessing the Effects of Trematode Infection on Invasive Green Crabs in Eastern North America

    PubMed Central

    Blakeslee, April M. H.; Keogh, Carolyn L.; Fowler, Amy E.; Griffen, Blaine D.

    2015-01-01

    A common signature of marine invasions worldwide is a significant loss of parasites (= parasite escape) in non-native host populations, which may confer a release from some of the harmful effects of parasitism (e.g., castration, energy extraction, immune activation, behavioral manipulation) and possibly enhance the success of non-indigenous species. In eastern North America, the notorious invader Carcinus maenas (European green crab) has escaped more than two-thirds its native parasite load. However, one of its parasites, a trematode (Microphallus similis), can be highly prevalent in the non-native region; yet little is known about its potential impacts. We employed a series of laboratory experiments to determine whether and how M. similis infection intensity influences C. maenas, focusing on physiological assays of body mass index, energy storage, and immune activation, as well as behavioral analyses of foraging, shelter utilization, and conspicuousness. We found little evidence for enduring physiological or behavioral impacts four weeks after experimental infection, with the exception of mussel handling time which positively correlated with cyst intensity. However, we did find evidence for a short-term effect of M. similis infection during early stages of infection (soon after cercarial penetration) via a significant drop in circulating immune cells, and a significant increase in the crabs’ righting response time. Considering M. similis is the only common parasite infecting C. maenas in eastern North America, our results for minimal lasting effects of the trematode on the crab’s physiology and behavior may help explain the crab’s continued prominence as a strong predator and competitor in the region. PMID:26030816

  4. Genetics of obesity.

    PubMed

    O'Rahilly, Stephen; Farooqi, I Sadaf

    2006-07-29

    Considerable attention is currently being paid to the secular changes in food intake and physical activity that underlie the increase in the prevalence of obesity that is apparent in many societies. While this is laudable it would be unwise to view these environmental factors in isolation from the biological factors that normally control body weight and composition and the compelling evidence that inter-individual differences in susceptibility to obesity have strong genetic determinants. This is particularly important, as it is only in the past decade that we have begun to obtain substantive information regarding the molecular constituents of pathways controlling mammalian energy balance and therefore, for the first time, are in a position to achieve a better mechanistic understanding of this disease. Population-based association and linkage studies have highlighted a number of loci at which genetic variation is associated with obesity and related phenotypes and the identification and characterization of monogenic obesity syndromes has been particularly fruitful. While there is widespread acceptance that hereditary factors might predispose to human obesity, it is frequently assumed that such factors would influence metabolic rate or the selective partitioning of excess calories into fat. However, it is notable that, thus far, all monogenic defects causing human obesity actually disrupt hypothalamic pathways and have a profound effect on satiety and food intake. To conclude, the evidence we have to date suggests that the major impact of genes on human obesity is just as likely (or perhaps more likely) to directly impact on hunger, satiety and food intake rather than metabolic rate or nutrient partitioning. At the risk of oversimplification, it seems that from an aetiological/genetic standpoint, human obesity appears less a metabolic than a neuro-behavioural disease.

  5. Genetics of obesity

    PubMed Central

    O'Rahilly, Stephen; Farooqi, I.Sadaf

    2006-01-01

    Considerable attention is currently being paid to the secular changes in food intake and physical activity that underlie the increase in the prevalence of obesity that is apparent in many societies. While this is laudable it would be unwise to view these environmental factors in isolation from the biological factors that normally control body weight and composition and the compelling evidence that inter-individual differences in susceptibility to obesity have strong genetic determinants. This is particularly important, as it is only in the past decade that we have begun to obtain substantive information regarding the molecular constituents of pathways controlling mammalian energy balance and therefore, for the first time, are in a position to achieve a better mechanistic understanding of this disease. Population-based association and linkage studies have highlighted a number of loci at which genetic variation is associated with obesity and related phenotypes and the identification and characterization of monogenic obesity syndromes has been particularly fruitful. While there is widespread acceptance that hereditary factors might predispose to human obesity, it is frequently assumed that such factors would influence metabolic rate or the selective partitioning of excess calories into fat. However, it is notable that, thus far, all monogenic defects causing human obesity actually disrupt hypothalamic pathways and have a profound effect on satiety and food intake. To conclude, the evidence we have to date suggests that the major impact of genes on human obesity is just as likely (or perhaps more likely) to directly impact on hunger, satiety and food intake rather than metabolic rate or nutrient partitioning. At the risk of oversimplification, it seems that from an aetiological/genetic standpoint, human obesity appears less a metabolic than a neuro-behavioural disease. PMID:16815794

  6. Ethics in reproductive genetics.

    PubMed

    Fletcher, J C; Evans, M I

    1992-12-01

    Ethics in reproductive genetics comprise descriptive ethics and normative ethics. Ethical problems before prenatal diagnosis involve genetic counseling and informed consent for the choice patients must make. Prenatal diagnosis using amniocentesis is controversial. An international survey of geneticists showed that 25% would do prenatal diagnosis for sex selection, and 17% would refer the couple elsewhere. Hungary (60%), India (37%), the US (34%), Canada (30%), Greece (29%), and Sweden (28%) would do prenatal diagnosis. The statistical incidence of positive findings after prenatal diagnosis does not exceed 4% of all cases when most couples choose abortion. Respect for parental choice and for nondirective counseling was supported in responses to 3 cases in the international survey that also had disclosure dilemmas included with abortion choices. 84% of respondents would be nondirective for XYY and 88% for XO. In India, Hungary, Turkey, and Norway, 46%, 40%, 40%, and 33%, respectively, would advise aborting an XO (Turner) fetus. A survey of 737 genetics and obstetricians and ethicists and clergy showed acceptability of abortion in singleton pregnancies and in twins associated strongly with the trimester of pregnancy, indication for selective termination, and fetal number. Prior group review of risks and benefits of experimental fetal therapy, case selection for experimental fetal therapy, the optimal informed-consent process for fetal therapy, twin pregnancies, refusal of proven fetal therapy, the lack of federal support for research in fetal diagnosis (preimplantation embryo diagnosis) and therapy, and sources of a moral obligation are also addressed. The Belmont Report on the ethics of biomedical research in the US proposed ethical principles to guide research with human subjects including the fetus: respect for parsons, beneficence, and justice.

  7. A comprehensive review of genetics and genetic testing in azoospermia

    PubMed Central

    Hamada, Alaa J; Esteves, Sandro C; Agarwal, Ashok

    2013-01-01

    Azoospermia due to obstructive and non-obstructive mechanisms is a common manifestation of male infertility accounting for 10-15% of such cases. Known genetic factors are responsible for approximately 1/3 of cases of azoospermia. Nonetheless, at least 40% of cases are currently categorized as idiopathic and may be linked to unknown genetic abnormalities. It is recommended that various genetic screening tests are performed in azoospermic men, given that their results may play vital role in not only identifying the etiology but also in preventing the iatrogenic transmission of genetic defects to offspring via advanced assisted conception techniques. In the present review, we examine the current genetic information associated with azoospermia based on results from search engines, such as PUBMED, OVID, SCIENCE DIRECT and SCOPUS. We also present a critical appraisal of use of genetic testing in this subset of infertile patients. PMID:23503954

  8. A comprehensive review of genetics and genetic testing in azoospermia.

    PubMed

    Hamada, Alaa J; Esteves, Sandro C; Agarwal, Ashok

    2013-01-01

    Azoospermia due to obstructive and non-obstructive mechanisms is a common manifestation of male infertility accounting for 10-15% of such cases. Known genetic factors are responsible for approximately 1/3 of cases of azoospermia. Nonetheless, at least 40% of cases are currently categorized as idiopathic and may be linked to unknown genetic abnormalities. It is recommended that various genetic screening tests are performed in azoospermic men, given that their results may play vital role in not only identifying the etiology but also in preventing the iatrogenic transmission of genetic defects to offspring via advanced assisted conception techniques. In the present review, we examine the current genetic information associated with azoospermia based on results from search engines, such as PUBMED, OVID, SCIENCE DIRECT and SCOPUS. We also present a critical appraisal of use of genetic testing in this subset of infertile patients.

  9. Genetic Counselling for Schizophrenia in the Era of Molecular Genetics

    PubMed Central

    Hodgkinson, Kathleen A; Murphy, Jillian; O’Neill, Sheri; Brzustowicz, Linda; Bassett, Anne S

    2012-01-01

    Objective To review the role of genetic counselling for individuals with psychiatric illnesses. Method Using schizophrenia as an example and including updated information about a genetic subtype (22q deletion syndrome), we discuss the value of the genetic counselling process in psychiatry, with support from the literature and our clinical experience. Results Genetic counselling, the process through which knowledge about the genetics of illnesses is shared, provides information on the inheritance of illnesses and their recurrence risks; addresses the concerns of patients, their families, and their health care providers; and supports patients and their families dealing with these illnesses. For comprehensive medical management, this service should be available to all individuals with schizophrenia and their families. Conclusions New findings in the genetics of psychiatric illness may have important clinical implications for patients and their families. PMID:11280080

  10. Thermodynamics and evolutionary genetics

    NASA Astrophysics Data System (ADS)

    Müller, Ingo

    2010-03-01

    Thermodynamics and evolutionary genetics have something in common. Thus, the randomness of mutation of cells may be likened to the random thermal fluctuations in a gas. And the probabilistic nature of entropy in statistical thermodynamics can be carried over to a population of haploid and diploid cells without any conceptual change. The energetic potential wells in which the atoms of a liquid are caught correspond to selective advantages for some phenotype over others. Thus, the eventual stable state in a population comes about as a compromise in the universal competition between entropy and energy.

  11. Genetics of pediatric epilepsy.

    PubMed

    Hani, Abeer J; Mikati, Husam M; Mikati, Mohamad A

    2015-06-01

    As the genetic etiologies of an expanding number of epilepsy syndromes are revealed, the complexity of the phenotype genotype correlation increases. As our review will show, multiple gene mutations cause different epilepsy syndromes, making identification of the specific mutation increasingly more important for prognostication and often more directed treatment. Examples of that include the need to avoid specific drugs in Dravet syndrome and the ongoing investigations of the potential use of new directed therapies such as retigabine in KCNQ2-related epilepsies, quinidine in KCNT1-related epilepsies, and memantine in GRIN2A-related epilepsies.

  12. Genetics of restrictive cardiomyopathy.

    PubMed

    Sen-Chowdhry, Srijita; Syrris, Petros; McKenna, William J

    2010-04-01

    Restrictive physiology, a severe form of diastolic dysfunction, is characteristically observed in the setting of constrictive pericarditis and myocardial restriction. The latter is commonly due to systemic diseases, some of which are inherited as mendelian traits (eg, hereditary amyloidosis), while others are multifactorial (eg, sarcoidosis). When restrictive physiology occurs as an early and dominant feature of a primary myocardial disorder, it may be termed restrictive cardiomyopathy. In the past decade, clinical and genetic studies have demonstrated that restrictive cardiomyopathy as such is part of the spectrum of sarcomeric disease and frequently coexists with hypertrophic cardiomyopathy in affected families.

  13. 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.

  14. Genetics of ectopia lentis.

    PubMed

    Sadiq, Mohammad Ali; Vanderveen, Deborah

    2013-01-01

    Hereditary ectopia lentis or lens subluxation can occur with and without systemic associations. Significant overlap can be found in the genetic mutations and pathogenesis of subluxated lenses in their isolated forms as well as with associated syndromes. Gene mutations have been identified for lens subluxation associated with Marfan syndrome, Weill Marchesani syndrome, Ectopia Lentis simplex, Ectopia Lentis et pupillae, Ehlers Danlos syndrome, homocystinuria, and sulfite oxidase deficiency. Herein we describe the ocular and systemic characteristics found in patients with ectopia lentis, as well as the gene mutations identified thus far.

  15. 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.

  16. Genetic Architecture of Colorectal Cancer

    PubMed Central

    Peters, Ulrike; Bien, Stephanie; Zubair, Niha

    2015-01-01

    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 arises 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 over 40 genetic regions to be 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 summarizing 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. PMID:26187503

  17. [Current options of preimplantion genetic screening and preimplantation genetic diagnostics].

    PubMed

    Šimečková, V

    The aim of this work is to summarize the current knowledge about preimplantation genetic screening and diagnostics. A review article. Department of Gynecology and Obstetrics, District Hospital Šternberk, IVF Clinic, Olomouc. Preimplantation genetic testing is a complex of genetic and molecular cytogenetic examinations, which can help to detect abnormalities in embryos before transfer into the uterus of the mother. These specialized examinations are based on the latest findings in genetics and assisted reproduction. The preimplantation genetic testing is necessarily associated with a method of in vitro fertilization. It is performed on isolated blastomeres on the third day of embryo cultivation. Nowadays, it is preferred trophectoderm examination of cells from the five-day blastocysts. Generally speaking, after preimplantation genetic testing, we can select only embryos without genetic load to transfer into uterus. Preimplantation genetic testing is an important part of treatment of infertility. Complex diagnostics and treatment of infertile couples are increasingly influenced by the development and use of advanced genomic technologies. Further development and application of these modern methods require close cooperation between the field of assisted reproduction and clinical genetics.

  18. 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

  19. The probability of parallel genetic evolution from standing genetic variation.

    PubMed

    MacPherson, A; Nuismer, S L

    2017-02-01

    Parallel evolution is often assumed to result from repeated adaptation to novel, yet ecologically similar, environments. Here, we develop and analyse a mathematical model that predicts the probability of parallel genetic evolution from standing genetic variation as a function of the strength of phenotypic selection and constraints imposed by genetic architecture. Our results show that the probability of parallel genetic evolution increases with the strength of natural selection and effective population size and is particularly likely to occur for genes with large phenotypic effects. Building on these results, we develop a Bayesian framework for estimating the strength of parallel phenotypic selection from genetic data. Using extensive individual-based simulations, we show that our estimator is robust across a wide range of genetic and evolutionary scenarios and provides a useful tool for rigorously testing the hypothesis that parallel genetic evolution is the result of adaptive evolution. An important result that emerges from our analyses is that existing studies of parallel genetic evolution frequently rely on data that is insufficient for distinguishing between adaptive evolution and neutral evolution driven by random genetic drift. Overcoming this challenge will require sampling more populations and the inclusion of larger numbers of loci.

  20. Digital genetics: unravelling the genetic basis of evolution.

    PubMed

    Adami, Christoph

    2006-02-01

    Digital genetics, or the genetics of digital organisms, is a new field of research that has become possible as a result of the remarkable power of evolution experiments that use computers. Self-replicating strands of computer code that inhabit specially prepared computers can mutate, evolve and adapt to their environment. Digital organisms make it easy to conduct repeatable, controlled experiments, which have a perfect genetic 'fossil record'. This allows researchers to address fundamental questions about the genetic basis of the evolution of complexity, genome organization, robustness and evolvability, and to test the consequences of mutations, including their interaction and recombination, on the fate of populations and lineages.