The ecology of male egg attendance in an arboreal breeding frog, Chirixalus eiffingeri (Anura: Rhacophoridae), from Taiwan

Field observations were conducted on egg attendance in Chirixalus eiffingeri from April to August 2003. Parental attendance during embryonic development was performed exclusively by males. The frequency of egg attendance was low (27%), but it had a distinct diel pattern in which males were observed to attend eggs more frequently at night than during the day. Attendance frequency significantly decreased with increasing developmental stage of the embryos, but it was not statistically significantly related to clutch size. Field observations confirmed that male frogs actively moisten egg clutches using their ventral surfaces, presumably to prevent desiccation of egg clutches. The non-significant relationship between hatching success and frequency of egg attendance suggests that embryonic survival of C. eiffingeri is more than a function of egg attendance, and ecological and environmental factors, such as climate and characteristics of microhabitats, may also influence the survivorship of the embryos.     

Resiliency factors protecting against teenage alcohol use and smoking: influences of religion, religious involvement and values, and ethnicity in the Missouri Adolescent Female Twin Study.

The objective of this study was to investigate the contribution of ethnicity (African American vs European/other ancestry), family religious affiliation, religious involvement, and religious values, to risk of alcohol and cigarette use in adolescent girls; and to estimate genetic and shared environmental effects on religious involvement and values. Telephone interviews were conducted with a sample of female like-sex twin pairs, aged 13-20 (n = 1687 pairs, including 220 minority pairs), as well as with one or both parents of twins aged 11-20 (n = 2111 families). These data, together with one-year follow-up twin questionnaire data, and two-year follow-up parent interview data, were used to compare ethnic differences. Proportional hazards regression models and genetic variance component models were fitted to the data. Despite higher levels of exposure to family, school and neighborhood environmental adversities, African American adolescents were less likely to become teenage drinkers or smokers. They showed greater religious involvement (frequency of attendance at religious services) and stronger religious values (eg belief in relying upon their religious beliefs to guide day-to-day living). Controlling for religious affiliation, involvement and values removed the ethnic difference in alcohol use, but had no effect on the difference in rates of smoking. Religious involvement and values exhibited high heritability in African Americans, but only modest heritability in EOAs. The strong protective effect of adolescent religious involvement and values, and its contribution to lower rates of African American alcohol use, was confirmed. We speculate about the possible association between high heritability of African American religious behavior and an accelerated maturation of religious values during adolescence.     

Quantitative tales of ethnic differentiation: measuring and using Roma/Gypsy ethnicity in statistical analyses

This paper analyses the use of ethnicity in quantitative models, focusing on Roma/Gypsy ethnic affiliation. Three research models are identified, together with characteristic measurement and model specification issues. A path model is estimated as a methodological example in order to explore the association of Roma/Gypsy ethnic affiliation with church attendance in Romania, using data from two surveys with national and Roma samples. Direct, mediated and moderated relationships involving ethnic affiliation are highlighted and discussed in relation to the processes of ethnic differentiation.     

Genetic influences on acquisition of tolerance to alcohol

Abstract

This paper provides a general review of the nature of tolerance to alcohol and describes specific studies designed to evaluate genetic influences on the acquisition of tolerance. Both environmental and genetic factors are involved in acquisition of either acute or chronic tolerance. Studies showing inbred strain differences in rates of acquisition of tolerance in mice are prima facie evidence for genetic influences, but the possible interactions between genes and environmental factors have not been investigated. Potential relationship between acutely and chronically acquired tolerance to alcohol is discussed.     

Association between stress and blood pressure variation in a Caribbean population

Based on the work of Selye (The Stress of Life, New York: McGraw-Hill, 1976) it is hypothesized that stress can produce physiological abnormalities, i.e., elevated blood pressure, and that social variables can be used as indicators or risk factors for disease. It is theorized that deviations from acceptable social patterns or traditional life-styles can produce stressful conditions that are associated with disease and that these situations can be demonstrated by examination of certain social characteristics. This association is examined among the Black Caribs of St. Vincent, West Indies. The social variables included in this analysis are marital status (single, married, widowed, or separated), frequency of church attendance (frequently, sometimes, seldom, or never), years of education, and number of children (for women only). The findings show that single individuals have higher pressures than married subjects and that males who never attend church have higher pressures than men who frequently attend church; a relationship was not demonstrated for females. Among males, as the years of education increased, blood pressure also increased, but for females, increased education was associated with lower pressures. Family size was not associated with systolic or diastolic pressure. The analysis of these selected social variables suggests that these variables influence male systolic and diastolic pressures, but only female diastolic pressure.     

Factors influencing Cinnamon Teal nest attendance patterns

Patterns of nest attendance in birds result from complex behaviours and influence the success of reproductive events. Incubation behaviours vary based on individual body condition, energy requirements and environmental factors. We assessed nest attendance patterns in Cinnamon Teal Spatula cyanoptera breeding in the San Luis Valley of Colorado in 2016–2017 using trail and video cameras to observe behaviours throughout incubation. We evaluated the effect of temporal, life‐history and environmental covariates on the frequency and duration of incubation recesses as well as the incubation constancy. There was considerable model uncertainty among the models used to evaluate recess frequency. Recess duration varied according to the interaction between nest age and a quadratic effect of time of day, with hens on older nests taking longer recesses in the afternoon and hens on nests earlier in incubation taking longer recesses in the morning and evening. Incubation constancy decreased with higher ambient temperatures in the study area. This study provides evidence that Cinnamon Teal modify their behaviour during incubation according to the age of the nest and the time of day. These results improve our knowledge of Cinnamon Teal breeding ecology and shed light on the behaviours that fast‐lived species may use to cope with environmental factors during nesting.     

The role of α-synuclein in the pathophysiology of alcoholism

Alcoholism has complex etiology and there is evidence for both genetic and environmental factors in its pathophysiology. Chronic, long-term alcohol abuse and alcohol dependence are associated with neuronal loss with the prefrontal cortex being particularly susceptible to neurotoxic damage. This brain region is involved in the development and persistence of alcohol addiction and neurotoxic damage is likely to exacerbate the reinforcing effects of alcohol and may hinder treatment. Understanding the mechanism of alcohol’s neurotoxic effects on the brain and the genetic risk factors associated with alcohol abuse are the focus of current research. Because of its well-established role in neurodegenerative and neuropsychological disorders, and its emerging role in the pathophysiology of addiction, here we review the genetic and epigenetic factors involved in regulating α-synuclein expression and its potential role in the pathophysiology of chronic alcohol abuse. Elucidation of the mechanisms of α-synuclein regulation may prove beneficial in understanding the role of this key synaptic protein in disease and its potential for therapeutic modulation in the treatment of substance use disorders as well as other neurodegenerative diseases.     

A religious upbringing reduces the influence of genetic factors on disinhibition: evidence for interaction between genotype and environment on personality.

Information on personality, on anxiety and depression and on several aspects of religion was collected in 1974 Dutch families consisting of adolescent and young adult twins and their parents. Analyses of these data showed that differences between individuals in religious upbringing, in religious affiliation and in participation in church activities are not influenced by genetic factors. The familial resemblance for different aspects of religion is high, but can be explained entirely by environmental influences common to family members. Shared genes do not contribute to familial resemblances in religion. The absence of genetic influences on variation in several dimensions of religion is in contrast to findings of genetic influences on a large number of other traits that were studied in these twin families. Differences in religious background are associated with differences in personality, especially in Sensation Seeking. Subjects with a religious upbringing, who are currently religious and who engage in church activities score lower on the scales of the Sensation Seeking Questionnaire. The most pronounced effect is on the Disinhibition scale. The resemblances between twins for the Disinhibition scale differ according to their religious upbringing. Receiving a religious upbringing seems to reduce the influence of genetic factors on Disinhibition, especially in males.     

Adolescent religiousness and its influence on substance use: preliminary findings from the Mid-Atlantic School Age Twin Study.

Research has consistently shown that religiousness is associated with lower levels of alcohol and drug use, but little is known about the nature of adolescent religiousness or the mechanisms through which it influences problem behavior in this age group. This paper presents preliminary results from the Mid-Atlantic School Age Twin Study, a prospective, population-based study of 6-18-year-old twins and their mothers. Factor analysis of a scale developed to characterize adolescent religiousness, the Religious Attitudes and Practices Inventory (RAPI), revealed three factors: theism, religious/spiritual practices, and peer religiousness. Twin correlations and univariate behavior-genetic models for these factors and a measure of belief that drug use is sinful reveal in 357 twin pairs that common environmental factors significantly influence these traits, but a minor influence of genetic factors could not be discounted. Correlations between the multiple factors of adolescent religiousness and substance use, comorbid problem behavior, mood disorders, and selected risk factors for substance involvement are also presented. Structural equation modeling illustrates that specific religious beliefs about the sinfulness of drugs and level of peer religiousness mediate the relationship between theistic beliefs and religious/spiritual practices on substance use. Limitations and future analyses are discussed.     

Focus: Addiction: Perceptions of Family Alcohol Use in a Young Adult Sample

Perceptions of family alcohol use have been linked to adolescent alcohol use behaviors, yet there have been no studies that have assessed this relationship in young adults. This study examined perceptions of family alcohol use and their association with participants’ self-reported alcohol use. Participants included 171 undergraduate students (mean age = 21.67, 71.9 percent female, 75.4 percent Caucasian). Participants completed measures assessing quantity and frequency of alcohol use, negative consequences of use, and sibling relationship quality. They also reported their perceptions of alcohol use for siblings and parents during a typical week. Perceptions of siblings’ quantity of weekly alcohol use were significantly associated with participants’ quantity of alcohol use (r = .21, p = .006) and frequency of alcohol use (r = .23, p = .002). Perceptions of parental alcohol use were not related to the participants’ alcohol use patterns.     

Genetic and environmental influences on alcohol use: DF analysis of NLSY kinship data

Research designs to study alcohol use and abuse have included twin, adoption and family history/high risk studies. Results have consistently implied a genetic factor in the aetiology of alcohol abuse. However, less research has been conducted in search of environmental factors. This study uses kinship structure in a large national dataset (the National Longitudinal Survey of Youth) to estimate (using DeFries-Fulker analysis) the extent of the shared genetic, non-shared genetic, shared environmental and non-shared environmental influences on alcohol use. The NLSY kinship sample contained 3890 pairs of cousins, half-siblings, full-siblings and twins between the ages of 14 and 21 in the initial year of the survey (1979). Estimates of heritability (h2) and shared environment (c2) were small to moderate for the entire dataset for both light drinking and heavy drinking behaviour, with h2 estimates slightly higher in each case. Non-shared genetic measures of self-esteem and locus of control accounted for a significant portion of the remaining variance in heavy drinking behaviour. Race and gender patterns showed c2 and h2 estimates that were also small to moderate for both light and heavy drinking behaviour. Significant non-shared effects were found for the White group for heavy drinking behaviour, and for male pairs for both heavy and light drinking behaviour. Additionally, implications and future directions are discussed.     

Genetics and genomics of alcohol sensitivity

Alcohol abuse and alcoholism incur a heavy socioeconomic cost in many countries. Both genetic and environmental factors contribute to variation in the inebriating effects of alcohol and alcohol addiction among individuals within and across populations. From a genetics perspective, alcohol sensitivity is a quantitative trait determined by the cumulative effects of multiple segregating genes and their interactions with the environment. This review summarizes insights from model organisms as well as human populations that represent our current understanding of the genetic and genomic underpinnings that govern alcohol metabolism and the sedative and addictive effects of alcohol on the nervous system.     

Basic research on heredity and alcohol: Implications for clinical application

Abstract

Alcoholism has been described as a behavioral condition comprised of symptoms of alcohol dependence and the psycho‐socio‐biologic consequences of chronic alcohol dependence. Progress in clarifying the role of genetic factors in explaining differences in onset of dependence upon alcohol, frequency of consequences of chronic alcohol use, and transmission of patterns of alcoholism within a family pedigree has been based upon use of diagnostic methods that reliably and validly separate alcohol dependence from alcohol abuse. Twin methods, which control for genotypic variation, and adoption studies, which control for differences in rearing, have provided significant support for a genetic vulnerability hypothesis for development of alcoholism and a genetic heterogeneity hypothesis for type of alcoholism. The author reviews data from basic and clinical investigation of two subtypes of alcoholism: one associated with antisocial personality, and one that is “familial” (family‐history‐positive alcoholism). Significant differences in onset and clinical course for these subtypes suggest that differential plans for matching treatment to the individual alcoholic may be warranted.     

Individual differences in plasma ALT, AST and GGT: contributions of genetic and environmental factors, including alcohol consumption

The causes of individuality of the plasma enzymes alanine aminotransferase (ALT; EC 2.6.1.2), aspartate aminotransferase (AST; EC 2.6.1.1) and gamma-glutamyl transferase (GGT; EC 2.3.2.2) were investigated in a study of 206 pairs of twins. Between-person variance was greater in men than women, while within-person variation was similar in both sexes. Plasma ALT and AST levels were affected by genetic factors, while GGT was affected by some environmental factor shared by co-twins. In the men, alcohol intake had a significant but small effect on all three enzyme levels, and since alcohol consumption was highly heritable, this appeared as a genetic influence on enzyme activities. The major factors involved in the observed correlations between these enzymes were a non-shared environmental factor other than alcohol affecting ALT, AST and GGT, and a genetic factor affecting only ALT and AST.     

No Evidence for Genome-Wide Interactions on Plasma Fibrinogen by Smoking,Alcohol Consumption and Body Mass Index: Results from Meta-Analyses of 80,607 Subjects

Plasma fibrinogen is an acute phase protein playing an important role in the blood coagulation cascade having strong associations with smoking, alcohol consumption and body mass index (BMI). Genome-wide association studies (GWAS) have identified a variety of gene regions associated with elevated plasma fibrinogen concentrations. However, little is yet known about how associations between environmental factors and fibrinogen might be modified by genetic variation. Therefore, we conducted large-scale meta-analyses of genome-wide interaction studies to identify possible interactions of genetic variants and smoking status, alcohol consumption or BMI on fibrinogen concentration. The present study included 80,607 subjects of European ancestry from 22 studies. Genome-wide interaction analyses were performed separately in each study for about 2.6 million single nucleotide polymorphisms (SNPs) across the 22 autosomal chromosomes. For each SNP and risk factor, we performed a linear regression under an additive genetic model including an interaction term between SNP and risk factor. Interaction estimates were meta-analysed using a fixed-effects model. No genome-wide significant interaction with smoking status, alcohol consumption or BMI was observed in the meta-analyses. The most suggestive interaction was found for smoking and rs10519203, located in the LOC123688 region on chromosome 15, with a p value of 6.2×10⁻⁸. This large genome-wide interaction study including 80,607 participants found no strong evidence of interaction between genetic variants and smoking status, alcohol consumption or BMI on fibrinogen concentrations. Further studies are needed to yield deeper insight in the interplay between environmental factors and gene variants on the regulation of fibrinogen concentrations.     

The Omega-3 Fatty Acid Eicosapentaenoic Acid Is Required for Normal Alcohol Response Behaviors in C. elegans

Alcohol addiction is a widespread societal problem, for which there are few treatments. There are significant genetic and environmental influences on abuse liability, and understanding these factors will be important for the identification of susceptible individuals and the development of effective pharmacotherapies. In humans, the level of response to alcohol is strongly predictive of subsequent alcohol abuse. Level of response is a combination of counteracting responses to alcohol, the level of sensitivity to the drug and the degree to which tolerance develops during the drug exposure, called acute functional tolerance. We use the simple and well-characterized nervous system of Caenorhabditis elegans to model the acute behavioral effects of ethanol to identify genetic and environmental factors that influence level of response to ethanol. Given the strong molecular conservation between the neurobiological machinery of worms and humans, cellular-level effects of ethanol are likely to be conserved. Increasingly, variation in long-chain polyunsaturated fatty acid levels has been implicated in complex neurobiological phenotypes in humans, and we recently found that fatty acid levels modify ethanol responses in worms. Here, we report that 1) eicosapentaenoic acid, an omega-3 polyunsaturated fatty acid, is required for the development of acute functional tolerance, 2) dietary supplementation of eicosapentaenoic acid is sufficient for acute tolerance, and 3) dietary eicosapentaenoic acid can alter the wild-type response to ethanol. These results suggest that genetic variation influencing long-chain polyunsaturated fatty acid levels may be important abuse liability loci, and that dietary polyunsaturated fatty acids may be an important environmental modulator of the behavioral response to ethanol.     

Varying coefficient model for gene-environment interaction: a non-linear look

MOTIVATION: The genetic basis of complex traits often involves the function of multiple genetic factors, their interactions and the interaction between the genetic and environmental factors. Gene-environment (G×E) interaction is considered pivotal in determining trait variations and susceptibility of many genetic disorders such as neurodegenerative diseases or mental disorders. Regression-based methods assuming a linear relationship between a disease response and the genetic and environmental factors as well as their interaction is the commonly used approach in detecting G×E interaction. The linearity assumption, however, could be easily violated due to non-linear genetic penetrance which induces non-linear G×E interaction. RESULTS: In this work, we propose to relax the linear G×E assumption and allow for non-linear G×E interaction under a varying coefficient model framework. We propose to estimate the varying coefficients with regression spline technique. The model allows one to assess the non-linear penetrance of a genetic variant under different environmental stimuli, therefore help us to gain novel insights into the etiology of a complex disease. Several statistical tests are proposed for a complete dissection of G×E interaction. A wild bootstrap method is adopted to assess the statistical significance. Both simulation and real data analysis demonstrate the power and utility of the proposed method. Our method provides a powerful and testable framework for assessing non-linear G×E interaction.     

Epidemiology and Genetic Epidemiology of the Liver Function Test Proteins

Background

The liver function test (LFT) is among the most commonly used clinical investigations to assess hepatic function, severity of liver diseases and the effect of therapies, as well as to detect drug-induced liver injury (DILI).

Aims

To determine the relative contribution of genetic and environmental factors as well as test and quantify the effects of sex, age, BMI and alcohol consumption to variation in liver function test proteins - including alanine amino transaminase (ALT), Albumin, gamma glutamyl transpeptidase (GGT), total bilirubin, total protein, total globulin, aspartate transaminase (AST), and alkaline phosphotase (ALP) - using the classical twin model.

Methods

Blood samples were collected from a total of 5380 twin pairs from the TwinsUK registry. We measured the expression levels of major proteins associated with the LFT, calculated BMI from measured weight and height and questionnaires were completed for alcohol consumption by the twins. The relative contribution of genetic and environmental factors to variation in the LFT proteins was assessed and quantified using a variance components model fitting approach.

Results

Our results show that (1) variation in all the LFTs has a significant heritable basis (h² ranging from 20% to 77%); (2) other than GGT, the LFTs are all affected to some extent by common environmental factors (c² ranging from 24% to 54%); and (3) a small but significant proportion of the variation in the LFTs was due to confounding effects of age, sex, BMI, and alcohol use.

Conclusions

Variation in the LFT proteins is under significant genetic and common environmental control although sex, alcohol use, age and BMI also contribute significantly to inter-individual variation in the LFT proteins. Understanding the underlying genetic contribution of liver function tests may help the interpretation of their results and explain wide variation among individuals.     

Lactate dehydrogenase: a polymorphism of Anoplarchus purpurescens: geographic variation in central California

Previous studies on the muscle lactate dehydrogenase polymorphism of the stichaeid fish Anoplarchus purpurescens in Puget Sound have demonstrated the existence of a clinal pattern of allele frequency. The LDH-A' allele was observed to increase toward the south, with several environmental factors showing correlation with this change in allele frequency. Populations from California were sampled in the present study to determine whether or not gene frequencies along an independent transect near the southern end of the species distribution are consistent with the interpretation that the geographic patterns reflect the influence of environmental factors. In California, the LDH-A' allele decreases in frequency to the south. This observation necessitates the reevaluation of possible environmental influences on the LDH polymorphism. Only one of several proposed hypotheses is completely consistent with the geographic patterns observed along both the Washington and California transects. However, the genetic differentiation along the California coast cannot be unequivically ascribed to the influence of environmental factors; current morphological data indicate the possibility of historical influences on the population genetic structure of California A. purpurescens.