CRIMINOLOGY, Issue 4 2000
ANTHONY WALSH
Criminology is in need of conceptual revival, and behavior genetics can provide the concepts and research design to accomplish this. Behavior genetics is a biologically-friendly environmental discipline that often tells us more about environmental effects on individual traits than about genetic effects. Anomie/strain theory is used to illustrate the usefulness of behavior genetics to criminological theories. Behavior genetics examines the individual differences that sort people into different modes of adaptation and that lead them to cope constructively or destructively with strain. Behavior genetics and other biosocial perspectives have the potential to help illuminate Agnew's (1997) extension of General Strain Theory (GST) into the developmental realm. [source]

DO RECENT FINDINGS IN PLANT MITOCHONDRIAL MOLECULAR AND POPULATION GENETICS HAVE IMPLICATIONS FOR THE STUDY OF GYNODIOECY AND CYTONUCLEAR CONFLICT?

EVOLUTION, Issue 5 2008
David E. McCauley
The coexistence of females and hermaphrodites in plant populations, or gynodioecy, is a puzzle recognized by Darwin. Correns identified cytoplasmic inheritance of one component of sex expression, now known as cytoplasmic male sterility (CMS). Lewis established cytonuclear inheritance of gynodioecy as an example of genetic conflict. Although biologists have since developed an understanding of the mechanisms allowing the joint maintenance of CMS and nuclear male fertility restorer genes, puzzles remain concerning the inheritance of sex expression and mechanisms governing the origination of CMS. Much of the theory of gynodioecy rests on the assumption of maternal inheritance of the mitochondrial genome. Here we review recent studies of the genetics of plant mitochondria, and their implications for the evolution and transmission of CMS. New studies of intragenomic recombination provide a plausible origin for the chimeric ORFs that characterize CMS. Moreover, evidence suggests that nonmaternal inheritance of mitochondria may be more common than once believed. These findings may have consequences for the maintenance of cytonuclear polymorphism, mitochondrial recombination, generation of gynomonoecious phenotypes, and interpretation of experimental crosses. Finally we point out that CMS can alter the nature of the cytonuclear conflict that may have originally selected for uniparental inheritance. [source]

ANTHROPOGENIC EFFECTS ON POPULATION GENETICS OF PHYTOPHAGOUS INSECTS ASSOCIATED WITH DOMESTICATED PLANTS

EVOLUTION, Issue 12 2007
Nadir Alvarez
The hypothesis of isolation by distance (IBD) predicts that genetic differentiation between populations increases with geographic distance. However, gene flow is governed by numerous factors and the correlation between genetic differentiation and geographic distance is never simply linear. In this study, we analyze the interaction between the effects of geographic distance and of wild or domesticated status of the host plant on genetic differentiation in the bean beetle Acanthoscelides obvelatus. Geographic distance explained most of the among-population genetic differentiation. However, IBD varied depending on the kind of population pairs for which the correlation between genetic differentiation and geographic distance was examined. Whereas pairs of beetle populations associated with wild beans showed significant IBD (P < 10,4), no IBD was found when pairs of beetle populations on domesticated beans were examined (P= 0.2992). This latter result can be explained by long-distance migrations of beetles on domesticated plants resulting from human exchanges of bean seeds. Beetle populations associated with wild beans were also significantly more likely than those on domesticated plants to contain rare alleles. However, at the population level, beetles on cultivated beans were similar in allelic richness to those on wild beans. This similarity in allelic richness combined with differences in other aspects of the genetic diversity (i.e., IBD, allelic diversity) is compatible with strongly contrasting effects of migration and drift. This novel indirect effect of human actions on gene flow of a serious pest of a domesticated plant has important implications for the spread of new adaptations such as resistance to pesticides. [source]

GENETICS AND RECENT HUMAN EVOLUTION

EVOLUTION, Issue 7 2007
Alan R. Templeton
Starting with "mitochondrial Eve" in 1987, genetics has played an increasingly important role in studies of the last two million years of human evolution. It initially appeared that genetic data resolved the basic models of recent human evolution in favor of the "out-of-Africa replacement" hypothesis in which anatomically modern humans evolved in Africa about 150,000 years ago, started to spread throughout the world about 100,000 years ago, and subsequently drove to complete genetic extinction (replacement) all other human populations in Eurasia. Unfortunately, many of the genetic studies on recent human evolution have suffered from scientific flaws, including misrepresenting the models of recent human evolution, focusing upon hypothesis compatibility rather than hypothesis testing, committing the ecological fallacy, and failing to consider a broader array of alternative hypotheses. Once these flaws are corrected, there is actually little genetic support for the out-of-Africa replacement hypothesis. Indeed, when genetic data are used in a hypothesis-testing framework, the out-of-Africa replacement hypothesis is strongly rejected. The model of recent human evolution that emerges from a statistical hypothesis-testing framework does not correspond to any of the traditional models of human evolution, but it is compatible with fossil and archaeological data. These studies also reveal that any one gene or DNA region captures only a small part of human evolutionary history, so multilocus studies are essential. As more and more loci became available, genetics will undoubtedly offer additional insights and resolutions of human evolution. [source]

THE LOCUS OF EVOLUTION: EVO DEVO AND THE GENETICS OF ADAPTATION

EVOLUTION, Issue 5 2007
Hopi E. Hoekstra
An important tenet of evolutionary developmental biology ("evo devo") is that adaptive mutations affecting morphology are more likely to occur in the cis -regulatory regions than in the protein-coding regions of genes. This argument rests on two claims: (1) the modular nature of cis -regulatory elements largely frees them from deleterious pleiotropic effects, and (2) a growing body of empirical evidence appears to support the predominant role of gene regulatory change in adaptation, especially morphological adaptation. Here we discuss and critique these assertions. We first show that there is no theoretical or empirical basis for the evo devo contention that adaptations involving morphology evolve by genetic mechanisms different from those involving physiology and other traits. In addition, some forms of protein evolution can avoid the negative consequences of pleiotropy, most notably via gene duplication. In light of evo devo claims, we then examine the substantial data on the genetic basis of adaptation from both genome-wide surveys and single-locus studies. Genomic studies lend little support to the cis -regulatory theory: many of these have detected adaptation in protein-coding regions, including transcription factors, whereas few have examined regulatory regions. Turning to single-locus studies, we note that the most widely cited examples of adaptive cis -regulatory mutations focus on trait loss rather than gain, and none have yet pinpointed an evolved regulatory site. In contrast, there are many studies that have both identified structural mutations and functionally verified their contribution to adaptation and speciation. Neither the theoretical arguments nor the data from nature, then, support the claim for a predominance of cis -regulatory mutations in evolution. Although this claim may be true, it is at best premature. Adaptation and speciation probably proceed through a combination of cis -regulatory and structural mutations, with a substantial contribution of the latter. [source]

A CENTENNIAL CELEBRATION FOR QUANTITATIVE GENETICS

EVOLUTION, Issue 5 2007
Derek A. Roff
Quantitative genetics is at or is fast approaching its centennial. In this perspective I consider five current issues pertinent to the application of quantitative genetics to evolutionary theory. First, I discuss the utility of a quantitative genetic perspective in describing genetic variation at two very different levels of resolution, (1) in natural, free-ranging populations and (2) to describe variation at the level of DNA transcription. Whereas quantitative genetics can serve as a very useful descriptor of genetic variation, its greater usefulness is in predicting evolutionary change, particularly when used in the first instance (wild populations). Second, I review the contributions of Quantitative trait loci (QLT) analysis in determining the number of loci and distribution of their genetic effects, the possible importance of identifying specific genes, and the ability of the multivariate breeder's equation to predict the results of bivariate selection experiments. QLT analyses appear to indicate that genetic effects are skewed, that at least 20 loci are generally involved, with an unknown number of alleles, and that a few loci have major effects. However, epistatic effects are common, which means that such loci might not have population-wide major effects: this question waits upon (QTL) analyses conducted on more than a few inbred lines. Third, I examine the importance of research into the action of specific genes on traits. Although great progress has been made in identifying specific genes contributing to trait variation, the high level of gene interactions underlying quantitative traits makes it unlikely that in the near future we will have mechanistic models for such traits, or that these would have greater predictive power than quantitative genetic models. In the fourth section I present evidence that the results of bivariate selection experiments when selection is antagonistic to the genetic covariance are frequently not well predicted by the multivariate breeder's equation. Bivariate experiments that combine both selection and functional analyses are urgently needed. Finally, I discuss the importance of gaining more insight, both theoretical and empirical, on the evolution of the G and P matrices. [source]

MULTILOCUS GENETICS AND THE COEVOLUTION OF QUANTITATIVE TRAITS

EVOLUTION, Issue 7 2006
Michael Kopp
Abstract We develop and analyze an explicit multilocus genetic model of coevolution. We assume that interactions between two species (mutualists, competitors, or victim and exploiter) are mediated by a pair of additive quantitative traits that are also subject to direct stabilizing selection toward intermediate optima. Using a weak-selection approximation, we derive analytical results for a symmetric case with equal locus effects and no mutation, and we complement these results by numerical simulations of more general cases. We show that mutualistic and competitive interactions always result in coevolution toward a stable equilibrium with no more than one polymorphic locus per species. Victimexploiter interactions can lead to different dynamic regimes including evolution toward stable equilibria, cycles, and chaos. At equilibrium, the victim is often characterized by a very large genetic variance, whereas the exploiter is polymorphic in no more than one locus. Compared to related one-locus or quantitative genetic models, the multilocus model exhibits two major new properties. First, the equilibrium structure is considerably more complex. We derive detailed conditions for the existence and stability of various classes of equilibria and demonstrate the possibility of multiple simultaneously stable states. Second, the genetic variances change dynamically, which in turn significantly affects the dynamics of the mean trait values. In particular, the dynamics tend to be destabilized by an increase in the number of loci. [source]

THE POPULATION GENETICS OF ADAPTATION ON CORRELATED FITNESS LANDSCAPES: THE BLOCK MODEL

EVOLUTION, Issue 6 2006
H. Allen Orr
Abstract Several recent theoretical studies of the genetics of adaptation have focused on the mutational landscape model, which considers evolution on rugged fitness landscapes (i.e., ones having many local optima). Adaptation in this model is characterized by several simple results. Here I ask whether these results also hold on correlated fitness landscapes, which are smoother than those considered in the mutational landscape model. In particular, I study the genetics of adaptation in the block model, a tunably rugged model of fitness landscapes. Considering the scenario in which adaptation begins from a high fitness wild-type DNA sequence, I use extreme value theory and computer simulations to study both single adaptive steps and entire adaptive walks. I show that all previous results characterizing single steps in adaptation in the mutational landscape model hold at least approximately on correlated landscapes in the block model; many entire-walk results, however, do not. [source]

QUANTITATIVE GENETICS OF PLASTRON SHAPE IN SLIDER TURTLES (TRACHEMYS SCRIPTA)

EVOLUTION, Issue 3 2006
Erin M. Myers
Abstract Shape variation is widespread in nature and embodies both a response to and a source for evolution and natural selection. To detect patterns of shape evolution, one must assess the quantitative genetic underpinnings of shape variation as well as the selective environment that the organisms have experienced. Here we used geometric morphometrics to assess variation in plastron shell shape in 1314 neonatal slider turtles (Trachemys scripta) from 162 clutches of laboratory-incubated eggs from two nesting areas. Multivariate analysis of variance indicated that nesting area has a limited role in describing plastron shape variation among clutches, whereas differences between individual clutches were highly significant, suggesting a prominent clutch effect. The covariation between plastron shape and several possible maternal effect variables (yolk hormone levels and egg dimensions) was assessed for a subset of clutches and found to be negligible. We subsequently employed several recently proposed methods for estimating heritability from shape variables, and generalized a univariate approach to accommodate unequal sample sizes. Univariate estimates of shape heritability based on Procrustes distances yielded large values for both nesting populations (h2, 0.86), and multivariate estimates of maximal additive heritability were also large for both nesting populations (h2max, 0.57). We also estimated the dominant trend in heritable shape change for each nesting population and found that the direction of shape evolution was not the same for the two sites. Therefore, although the magnitude of shape evolution was similar between nesting populations, the manner in which plastron shape is evolving is not. We conclude that the univariate approach for assessing quantitative genetic parameters from geometric morphometric data has limited utility, because it is unable to accurately describe how shape is evolving. [source]

THE POPULATION GENETICS OF SPOROPHYTIC SELF-INCOMPABILITY IN SENECIO SQUALIDUS L. (ASTERACEAE): THE NUMBER, FREQUENCY, AND DOMINANCE INTERACTIONS OF S ALLELES ACROSS ITS BRITISH RANGE

EVOLUTION, Issue 2 2006
Adrian C. Brennan
Abstract Sporophytic self-incompatibility (SSI) was studied in 11 British Senecio squalidus populations to quantify mating system variation and determine how its recent colonization of the United Kingdom has influenced its mating behavior. S allele number, frequency, and dominance interactions in populations were assessed using full diallels of controlled pollinations. A mean of 5.1 S alleles per population was observed, and no population contained more than six S alleles. Numbers of S alleles within populations of S. squalidus declined with increasing distance from the center of its introduction (Oxford). Cross-classification of S alleles allowed an estimate of approximately seven and no more than 11 S alleles for the entire British S. squalidus population. The low number of S alleles observed in British S. squalidus compared to other SI species is consistent with the population bottleneck associated with S. squalidus introduction to the Oxford Botanic Garden and subsequent colonization of Britain. Extensive S allele dominance interactions were observed to be a feature of the S. squalidus SSI system and may represent an adaptive response to improve limited mate availability imposed by the presence of so few S alleles. Multilocus allozyme genotypes were also identified for individuals in all populations and geographic patterns of S locus and allozyme loci variation investigated. Less interpopulation structure was observed for the S locus than for allozyme diversity-a finding indicative of the effects of negative frequency-dependent selection at the S locus maintaining equal S phenotypes within populations and enhancing effective migration between populations [source]

MULTIVARIATE QUANTITATIVE GENETICS AND THE LEK PARADOX: GENETIC VARIANCE IN MALE SEXUALLY SELECTED TRAITS OF DROSOPHILA SERRATA UNDER FIELD CONDITIONS

EVOLUTION, Issue 12 2004
Emma Hine
Abstract Single male sexually selected traits have been found to exhibit substantial genetic variance, even though natural and sexual selection are predicted to deplete genetic variance in these traits. We tested whether genetic variance in multiple male display traits of Drosophila serrata was maintained under field conditions. A breeding design involving 300 field-reared males and their laboratory-reared offspring allowed the estimation of the genetic variance-covariance matrix for six male cuticular hydrocarbons (CHCs) under field conditions. Despite individual CHCs displaying substantial genetic variance under field conditions, the vast majority of genetic variance in CHCs was not closely associated with the direction of sexual selection measured on field phenotypes. Relative concentrations of three CHCs correlated positively with body size in the field, but not under laboratory conditions, suggesting condition-dependent expression of CHCs under field conditions. Therefore condition dependence may not maintain genetic variance in preferred combinations of male CHCs under field conditions, suggesting that the large mutational target supplied by the evolution of condition dependence may not provide a solution to the lek paradox in this species. Sustained sexual selection may be adequate to deplete genetic variance in the direction of selection, perhaps as a consequence of the low rate of favorable mutations expected in multiple trait systems. [source]

THE POPULATION GENETICS OF ADAPTATION: THE ADAPTATION OF DNA SEQUENCES

EVOLUTION, Issue 7 2002
H. Allen Orr
Abstract I describe several patterns characterizing the genetics of adaptation at the DNA level. Following Gillespie (1983, 1984, 1991), I consider a population presently fixed for the ith best allele at a locus and study the sequential substitution of favorable mutations that results in fixation of the fittest DNA sequence locally available. Given a wild type sequence that is less than optimal, I derive the fitness rank of the next allele typically fixed by natural selection as well as the mean and variance of the jump in fitness that results when natural selection drives a substitution. Looking over the whole series of substitutions required to reach the best allele, I show that the mean fitness jumps occurring throughout an adaptive walk are constrained to a twofold window of values, assuming only that adaptation begins from a reasonably fit allele. I also show that the first substitution and the substitution of largest effect account for a large share of the total fitness increase during adaptation. I further show that the distribution of selection coefficients fixed throughout such an adaptive walk is exponential (ignoring mutations of small effect), a finding reminiscent of that seen in Fisher's geometric model of adaptation. Last, I show that adaptation by natural selection behaves in several respects as the average of two idealized forms of adaptation, perfect and random. [source]

THE ECOLOGY AND GENETICS OF FITNESS IN CHLAMYDOMONAS.

EVOLUTION, Issue 1 2002
VIII.
Abstract According to classical evolutionary theory, sexual recombination can generate the variation necessary to adapt to changing environments and thereby confer an evolutionary advantage of sexual over asexual reproduction. Using the green alga, Chlamydomonas reinhardtii, we investigated the effect of a single sexual episode on adaptation of heterotrophic growth on different carbon sources. In an initial mixture of isolates, sex was induced and the resulting offspring constituted the sexual populations, along with any unmated vegetative cells; the unmated mixture of isolates represented the asexual populations. Mean and variance in division rates (i.e., fitness) were measured four times during approximately 50 generations of vegetative growth in the dark on all possible combinations of four carbon sources. Consistent with effects of recombination of epistatic genes in linkage disequilibrium, sexual populations initially had a higher variance in fitness, but their mean fitness was lower than that of asexual populations, possibly due to recombinational load. Subsequently, fitness of sexual populations exceeded that of asexual ones, but finally they regained parity in both mean and variance of fitness. Although recombination was not more effective on more complex substrates, these results generally support the idea that sex can accelerate adaptation to novel environments. [source]

QUANTITATIVE GENETICS OF SEXUAL PLASTICITY: THE ENVIRONMENTAL THRESHOLD MODEL AND GENOTYPE-BY-ENVIRONMENT INTERACTION FOR PHALLUS DEVELOPMENT IN THE SNAIL BULINUS TRUNCATUS

EVOLUTION, Issue 5 2000
Marie-France Ostrowski
Abstract Sexual polymorphisms are model systems for analyzing the evolution of reproductive strategies. However, their plasticity and other binary traits have rarely been studied, with respect to environmental variables. A possible reason is that, although threshold models offer an adequate quantitative genetics framework for binary traits in a single environment, analyzing their plasticity requires more refined empirical and theoretical approaches. The statistical framework proposed here, based on the environmental threshold model (ETM), should partially fill this gap. This methodology is applied to an empirical dataset on a plastic sexual polymorphism, aphally, in the snail Bulinus truncatus. Aphally is characterized by the co-occurrence of regular hermaphrodites (euphallics) together with hermaphrodites deprived of the male copulatory organ (aphallics). Reaction norms were determined for 40 inbred lines, distributed at three temperatures, in a first experiment. A second experiment allowed us to rule out maternal effects. We confirmed the existence of high broad-sense heritabilities as well as a positive effect of high temperatures on aphally. However a significant genotype-by-environment interaction was detected for the first time, suggesting that sexual plasticity itself can respond to selection. A nested series of four ETM-like models was developed for estimating genetical effects on both mean aphally rate and plasticity. These models were tested using a maximum-likelihood procedure and fitted to aphally data. Although no perfect fit of models to data was observed, the refined versions of ETM models conveniently reduce the analysis of complex reaction norms of binary traits into standard quantitative genetics parameters, such as genetic values and environmental variances. [source]

REINFORCEMENT AND THE GENETICS OF NONRANDOM MATING

EVOLUTION, Issue 1 2000
Maria R. Servedio
Abstract., The occurrence of reinforcement is compared when premating isolation is caused by the spread of a gene causing females to prefer to mate with males carrying a population-specific trait (a "preference" model) and by a gene that causes females to prefer to mate with males that share their own trait phenotype (an "assortative mating" model). Both two-island models, which have symmetric gene flow, and continent-island models, which have one-way gene flow, are explored. Reinforcement is found to occur much more easily in a two-island assortative mating model than in any of the other three models. This is due primarily to the fact that in this model the assortative mating allele will automatically become genetically associated in each population with the trait allele that is favored by natural selection on that island. In contrast, natural selection on the trait both favors and opposes the evolution of premating isolation in the two-island preference model, depending on the particular population. These results imply that species recognition in the context of mating may evolve particularly easily when it targets cues that are favored by natural selection in each population. In the continent-island models, reinforcement is found to occur more often under the preference model than the assortative mating model, thus reversing the trend from the two-island models. Patterns of population subdivision may therefore play a role in determining what types of premating isolation may evolve. [source]

MIGRAINE: EPIDEMIOLOGY, GENETICS, AND COMORBIDITY

HEADACHE, Issue 4 2004
Article first published online: 13 APR 200
No abstract is available for this article. [source]

PROPOSAL OF ECTOCARPUS SILICULOSUS (ECTOCARPALES, PHAEOPHYCEAE) AS A MODEL ORGANISM FOR BROWN ALGAL GENETICS AND GENOMICS,

JOURNAL OF PHYCOLOGY, Issue 6 2004
Akira F. Peters
The emergence of model organisms that permit the application of a powerful combination of genomic and genetic approaches has been a major factor underlying the advances that have been made in the past decade in dissecting the molecular basis of a wide range of biological processes. However, the phylogenetic distance separating marine macroalgae from these model organisms, which are mostly from the animal, fungi, and higher plant lineages, limits the latters' applicability to problems specific to macroalgal biology. There is therefore a pressing need to develop similar models for the macroalgae. Here we describe a survey of potential model brown algae in which particular attention was paid to characteristics associated with a strong potential for genomic and genetic analysis, such as a small nuclear genome size, sexuality, and a short life cycle. Flow cytometry of nuclei isolated from zoids showed that species from the Ectocarpales possess smaller haploid genomes (127,290 Mbp) than current models among the Laminariales (580,720 Mbp) and Fucales (1095,1271 Mbp). Species of the Ectocarpales may complete their life histories in as little as 6 weeks in laboratory culture and are amenable to genetic analyses. Based on this study, we propose Ectocarpus siliculosus (Dillwyn) Lyngbye as an optimal choice for a general model organism for the molecular genetics of the brown algae. [source]

PRELIMINARY ANALYSIS OF QUANTITATIVE GENETICS AND PHENOTYPIC PLASTICITY IN AULACOSEIRA SUBARCTICA (BACILLAR-IOPHYTA)

JOURNAL OF PHYCOLOGY, Issue 2000
S. M. Edgar
Several clones of Aulacoseira subarctica were isolated from Yellowstone, Lewis, and East Rosebud Lakes (Montana, Wyoming). Two to four clones from each lake were grown in batch cultures under three light intensities, 2, 11.4 and 115 ,E m,2 s,1. Clones were conditioned to their light environment for a three-week period. Inoculants from the conditioned clones taken during log phase of growth, were grown until in log phase, then samples were collected. Five randomly chosen valves for 2 replicates of each clone were examined using a scanning electron microscope and captured on film at a magnification of 20,000x. Each image was digitized and quantitative morphometric characters were measured. A preliminary quantitative genetic analysis was performed on selected characters within each light environment. Plasticity of characters within clones across the three light regimes were also examined. The amount of variability found within characters in A. subarctica will be discussed in terms of environmental, genetic, and microenvironmental sources. [source]

IMAGING GENETICS: CONTRIBUTIONS FROM TWIN STUDIES

PSYCHOPHYSIOLOGY, Issue 2008
Article first published online: 12 AUG 200
No abstract is available for this article. [source]

Where's the Conservation in Conservation Genetics?

CONSERVATION BIOLOGY, Issue 3 2008
CRISTIANO VERNESI
No abstract is available for this article. [source]

Interleukin-1 receptor antagonist and tumour necrosis factor-alpha gene polymorphisms in Turkish patients with allergic contact dermatitis

CONTACT DERMATITIS, Issue 2 2009
Ilgen Ertam
Background: It has been shown that the family of interleukin-1 receptor antagonist (IL-1 RA) and tumour necrosis factor-alpha (TNF,) genes are polymorphic and related to some inflammatory diseases. Allergic contact dermatitis is the classic presentation of delayed-type hypersensitivity responses to exogenous agents. A number of genes playing role in inflammatory response may be associated with allergic contact dermatitis. Objectives: To investigate whether there is an association between IL-1RA and TNF, gene polymorphisms and allergic contact dermatitis in Turkish patients with allergic contact dermatitis. Methods: This study was performed by the collaboration of Departments of Dermatology and Medical Genetics, Ege University, Faculty of Medicine. A total of 50 patients (31 females and 19 males) with allergic contact dermatitis, and 100 age- and sex-matched controls (58 females and 42 males) were included in the study. IL-1RA Variable Number of Tandem Repeats (VNTR) polymorphism in intron 2 and TNF,-308G-A polymorphism were genotyped by using polymerase chain reaction and agarose gel electrophoresis. Results: The frequency of IL-1RA 1/2 (48%) genotype was significantly higher (P = 0.002) in patient group than that is found in control group (22%). The frequency of TNF, (TNF G-308A) G/G genotype was significantly higher in patient group (68%) than that is found in control group (31%) (P = 0.008). Conclusions: Our findings suggest that TNF, (G/G) gene polymorphism may play role in susceptibility to allergic contact dermatitis in Turkish patients. [source]

Morphological irregularities and features of resistance to apoptosis in the dcp-1/pita double mutated egg chambers during Drosophila oogenesis

CYTOSKELETON, Issue 1 2005
Ioannis P. Nezis
Abstract In the present study, we demonstrate the most novel characteristic morphological features of Drosophila egg chambers lacking both dcp-1 and pita functions in the germline cells. Dcp-1 is an effector caspase and it has been previously shown to play an important role during Drosophila oogenesis [McCall and Steller, 1998 : Science 279 : 230,234; Laundrie et al., 2003 : Genetics 165 : 1881,1888; Peterson et al., 2003 : Dev Biol 260 : 113,123]. The completion of sequencing and annotation of the Drosophila genome has revealed that the dcp-1 gene is nested within an intron of another distinct gene, called pita, a member of the C2H2 zinc finger protein family that regulates transcriptional initiation. The dcp-1,/,/pita,/, nurse cells exhibit euchromatic nuclei (delay of apoptosis) during the late stages of oogenesis, as revealed by conventional light and electron microscopy. The phalloidin-FITC staining discloses significant defects in actin cytoskeleton arrangement. The actin bundles fail to organize properly and the distribution of actin filaments in the ring canals is changed compared to the wild type. The oocyte and the chorion structures have been also modified. The oocyte nucleus is out of position and the chorion appears to contain irregular foldings, while the respiratory filaments obtain an altered morphology. The dcp-1,/,/pita,/, egg chambers do not exhibit the rare events of spontaneously induced apoptosis, observed for the wild type flies, during mid-oogenesis. Interestingly, the mutated egg chambers are protected by staurosporine-induced apoptosis in a percentage of 40%, strongly suggesting the essential role of dcp-1 and/or pita during mid-oogenesis. Cell Motil. Cytoskeleton 60:14,23, 2005. © 2004 Wiley-Liss, Inc. [source]

Genetics of anxiety disorders: the complex road from DSM to DNA,

DEPRESSION AND ANXIETY, Issue 11 2009
Jordan W. Smoller M.D. Sc.D.
Abstract Anxiety disorders are among the most common psychiatric disorders, affecting one in four individuals over a lifetime. Although our understanding of the etiology of these disorders is incomplete, familial and genetic factors are established risk factors. However, identifying the specific casual genes has been difficult. Within the past several years, advances in molecular and statistical genetic methods have made the genetic dissection of complex disorders a feasible project. Here we provide an overview of these developments, with a focus on their implications for genetic studies of anxiety disorders. Although the genetic and phenotypic complexity of the anxiety disorders present formidable challenges, advances in neuroimaging and experimental animal models of anxiety and fear offer important opportunities for discovery. Real progress in identifying the genetic basis of anxiety disorders will require integrative approaches that make use of these biologic tools as well as larger-scale genomic studies. If successful, such efforts may yield novel and more effective approaches for the prevention and treatment of these common and costly disorders. Depression and Anxiety, 2009. © 2009 Wiley-Liss, Inc. [source]

Genetics of type 2 diabetes mellitus: status and perspectives

DIABETES OBESITY & METABOLISM, Issue 2 2005
Lars Hansen
Throughout the last decade, molecular genetic studies of non-autoimmune diabetes mellitus have contributed significantly to our present understanding of this disease's complex aetiopathogenesis. Monogenic forms of diabetes (maturity-onset diabetes of the young, MODY) have been identified and classified into MODY1,6 according to the mutated genes that by being expressed in the pancreatic ,-cells confirm at the molecular level the clinical presentation of MODY as a predominantly insulin secretory deficient form of diabetes mellitus. Genomewide linkage studies of presumed polygenic type 2 diabetic populations indicate that loci on chromosomes 1q, 5q, 8p, 10q, 12q and 20q contain susceptibility genes. Yet, so far, the only susceptibility gene, calpain-10 (CAPN10), which has been identified using genomewide linkage studies, is located on chromosome 2q37. Mutation analyses of selected ,candidate' susceptibility genes in various populations have also identified the widespread Pro12Ala variant of the peroxisome proliferator-activated receptor-, and the common Glu23Lys variant of the ATP-sensitive potassium channel, Kir6.2 (KCNJ11). These variants may contribute significantly to the risk type 2 diabetes conferring insulin resistance of liver, muscle and fat (Pro12Ala) and a relative insulin secretory deficiency (Glu23Lys). It is likely that, in the near future, the recent more detailed knowledge of the human genome and insights into its haploblocks together with the developments of high-throughput and cheap genotyping will facilitate the discovery of many more type 2 diabetes gene variants in study materials, which are statistically powered and phenotypically well characterized. The results of these efforts are likely to be the platform for major progress in the development of personalized antidiabetic drugs with higher efficacy and few side effects. [source]

Current literature in diabetes

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2009
Article first published online: 13 FEB 200
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of diabetes/metabolism. Each bibliography is divided into 26 sections: 1 Reviews; 2 General; 3 Genetics; 4 Epidemiology; 5 Immunology; 6 Obesity; 7 Prediction and Prevention; 8 Intervention: a) General; b) Care; c) Drug Therapy; d)Economics; e) Gene therapy; f) Nursing; g) Nutrition; h) Surgery; i) Transplantation; 9 Pathology and Complications: a) General; b) Cardiovascular; c) Eye disease; d) Gestational and fetal; e) Neurological; f) Podiatrical; g) Renal; 10 Endocrinology & Metabolism; 11 Experimental Studies; 12 Diagnosis and Techniques. Within each section, articles are listed in alphabetical order with respect to author [source]

Current literature in diabetes

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 7 2008
Article first published online: 29 SEP 200
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of diabetes/metabolism. Each bibliography is divided into 26 sections: 1 Reviews; 2 General; 3 Genetics; 4 Epidemiology; 5 Immunology; 6 Obesity; 7 Prediction and Prevention; 8 Intervention: a) General; b) Care; c) Drug Therapy; d)Economics; e) Gene therapy; f) Nursing; g) Nutrition; h) Surgery; i) Transplantation; 9 Pathology and Complications: a) General; b) Cardiovascular; c) Eye disease; d) Gestational and fetal; e) Neurological; f) Podiatrical; g) Renal; 10 Endocrinology & Metabolism; 11 Experimental Studies; 12 Diagnosis and Techniques. Within each section, articles are listed in alphabetical order with respect to author [source]

Current literature in diabetes

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2008
Article first published online: 21 AUG 200
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of diabetes/metabolism. Each bibliography is divided into 26 sections: 1 Reviews; 2 General; 3 Genetics; 4 Epidemiology; 5 Immunology; 6 Obesity; 7 Prediction and Prevention; 8 Intervention: a) General; b) Care; c) Drug Therapy; d)Economics; e) Gene therapy; f) Nursing; g) Nutrition; h) Surgery; i) Transplantation; 9 Pathology and Complications: a) General; b) Cardiovascular; c) Eye disease; d) Gestational and fetal; e) Neurological; f) Podiatrical; g) Renal; 10 Endocrinology & Metabolism; 11 Experimental Studies; 12 Diagnosis and Techniques. Within each section, articles are listed in alphabetical order with respect to author [source]

Current literature in diabetes

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2008
Article first published online: 8 JUL 200
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of diabetes/metabolism. Each bibliography is divided into 26 sections: 1 Reviews; 2 General; 3 Genetics; 4 Epidemiology; 5 Immunology; 6 Obesity; 7 Prediction and Prevention; 8 Intervention: a) General; b) Care; c) Drug Therapy; d)Economics; e) Gene therapy; f) Nursing; g) Nutrition; h) Surgery; i) Transplantation; 9 Pathology and Complications: a) General; b) Cardiovascular; c) Eye disease; d) Gestational and fetal; e) Neurological; f) Podiatrical; g) Renal; 10 Endocrinology & Metabolism; 11 Experimental Studies; 12 Diagnosis and Techniques. Within each section, articles are listed in alphabetical order with respect to author [source]

Current literature in diabetes

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 4 2008
Article first published online: 24 APR 200
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of diabetes/metabolism. Each bibliography is divided into 26 sections: 1 Reviews; 2 General; 3 Genetics; 4 Epidemiology; 5 Immunology; 6 Obesity; 7 Prediction and Prevention; 8 Intervention: a) General; b) Care; c) Drug Therapy; d)Economics; e) Gene therapy; f) Nursing; g) Nutrition; h) Surgery; i) Transplantation; 9 Pathology and Complications: a) General; b) Cardiovascular; c) Eye disease; d) Gestational and fetal; e) Neurological; f) Podiatrical; g) Renal; 10 Endocrinology & Metabolism; 11 Experimental Studies; 12 Diagnosis and Techniques. Within each section, articles are listed in alphabetical order with respect to author [source]

Current literature in diabetes

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 3 2008
Article first published online: 25 FEB 200
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of diabetes/metabolism. Each bibliography is divided into 26 sections: 1 Reviews; 2 General; 3 Genetics; 4 Epidemiology; 5 Immunology; 6 Obesity; 7 Prediction and Prevention; 8 Intervention: a) General; b) Care; c) Drug Therapy; d)Economics; e) Gene therapy; f) Nursing; g) Nutrition; h) Surgery; i) Transplantation; 9 Pathology and Complications: a) General; b) Cardiovascular; c) Eye disease; d) Gestational and fetal; e) Neurological; f) Podiatrical; g) Renal; 10 Endocrinology & Metabolism; 11 Experimental Studies; 12 Diagnosis and Techniques. Within each section, articles are listed in alphabetical order with respect to author [source]