Variation and Variability in Drosophila Grooming Behavior

Behavioral differences can be observed between species or populations (variation) or between individuals in a genetically similar population (variability). Here, we investigate genetic differences as a possible source of variation and variability in Drosophila grooming. Grooming confers survival and social benefits. Grooming features of five Drosophila species exposed to a dust irritant were analyzed. Aspects of grooming behavior, such as anterior to posterior progression, were conserved between and within species. However, significant differences in activity levels, proportion of time spent in different cleaning movements, and grooming syntax were identified between species. All species tested showed individual variability in the order and duration of action sequences. Genetic diversity was not found to correlate with grooming variability within a species: melanogaster flies bred to increase or decrease genetic heterogeneity exhibited similar variability in grooming syntax. Individual flies observed on consecutive days also showed grooming sequence variability. Standardization of sensory input using optogenetics reduced but did not eliminate this variability. In aggregate, these data suggest that sequence variability may be a conserved feature of grooming behavior itself. These results also demonstrate that large genetic differences result in distinguishable grooming phenotypes (variation), but that genetic heterogeneity within a population does not necessarily correspond to an increase in the range of grooming behavior (variability).

Genetic and Brain Mechanisms of Addictive Behavior and Neuroadaptation

Genetic differences play a role in the susceptibility to addictive drug use, the probability that the use of these drugs will escalate and result in a drug use disorder, and whether relapse to use will occur during or after treatment [...]

Genetic advantage and equality of opportunity in education: Two definitions and an empirical application

The literature of Equality of Opportunity (EOp) has long acknowledged the existence of 'talents', 'innate ability' or 'genetic ability'. Nonetheless, attempts to explicitly incorporate a measure of innate ability in the quantification of EOp have been rare. On the other hand, the literature of social-science genetics has found credible genetic-based components of EOp, without an explicit quantification of overall EOp. In addition, there exists prevalent disagreement within both kinds of literature on whether innate ability should be perceived as a fair or unfair source of advantage. This paper proposes to quantify EOp while explicitly including a genetic-based measure of innate ability. It proposes two formal definitions of EOp that draw on both stances regarding the compensation of innate ability. Novel testable implications are derived. The educational attainment polygenic index is used as a measure of innate ability while correcting for genetic nurture and accounting for the correlation between genes and other circumstances. An empirical application in the US Health and Retirement Study finds that the share of inequality of opportunity is 26% under the view that genetic differences are unfair sources of advantage and 21% otherwise. A comparative analysis over cohorts reveals that the trend in EOp depends on the definition adopted; if genetic advantage is a fair source of inequality then EOp has improved; the opposite holds if one considers genetic advantage an unfair source of inequality. These results highlight the importance of accounting for genetic differences in the EOp framework.

Sex Differences in Migraine: A Twin Study

Migraine is a neurological disorder with a prominent sex difference such that two thirds of sufferers are female. The mechanisms behind the preponderance of migraine in women have yet to be elucidated. With data on 51,872 participants from the Swedish Twin Registry, we report results from two distinct analyses intended to clarify the degree to which genetic and environmental factors contribute to sex differences in migraine. First, we fit a sex-limitation model to determine if quantitative genetic differences (i.e., is migraine equally heritable across men and women) and/or qualitative genetic differences (i.e., are different genes involved in migraine across men and women) were present. Next, we used a multilevel logistic regression model to compare the prevalence of migraine in individuals from opposite-sex and same-sex twin pairs to determine whether differences in the prenatal hormone environment contribute to migraine risk. In the final analytic sample, women were found to have a significantly higher rate of migraine without aura relative to men (17.6% vs. 5.5%). The results from an ADE sex-limitation model indicate that migraine is equally heritable in men and women, with a broad sense heritability of 0.45, (95% CI = 0.40–0.50), while results from a reduced AE sex-limitation model provide subtle evidence for differences in the genes underlying migraine across men and women. The logistic regression analysis revealed a significant increase in migraine risk for females with a male co-twin relative to females with a female co-twin (OR = 1.51, 95% CI = 1.26–1.81). These results suggest that the prominent sex difference in migraine prevalence is not entirely accounted for by genetic factors, while demonstrating that masculinization of the prenatal environment may increase migraine risk for females. This effect points to a potential prenatal neuroendocrine factor in the development of migraine.

Features of engraftment and rejection of ear alatransplants in laboratory rats

A method for revealing genetic affinity between laboratory rats has been developed, which is based on the transplantation of ear skin-chondrocyte allografts onto the surface of a full-thickness skin defect. On the example of Wistar rats (laboratory rats were taken from three research institutes), it was shown that the rejection of allografts occurs in the interval between 8 and 21 days with the same genetic differences that existed between the animals. However, at the same time, only those structures of ear allografts such as the dermis, epidermis and its derivatives die and are rejected, but the layers of chondrocytes are submerged under the granulation tissue and remain in a viable position for at least 210 days. The latter phenomenon is probably due to the membranes that cover the chondrocytes and act as an immunological barrier.

Optimal Plot Dimensions for Performance Testing of Hybrid Potato in the Field

Field trials to evaluate the performance of new varieties are an essential component of potato breeding. Besides the genetic differences, environmental factors can lead to variation in a trial. In variety trials, the observed differences amongst varieties should reflect genetic differences, without a large impact of the random or systematic variation in the field. One way to reduce within-field variation is to adjust the plot size and its shape in a trial. Two years of field trials in which individual plants in 90-plant plots of both diploid hybrid and tetraploid varieties were measured provided data to derive relationships between LSD% and plot size and shape. We provide a method to estimate the equations to calculate the expected variation when using different plot dimensions in a relatively homogeneous trial field for tuber yield, tuber volume, tuber count, tuber shape and the standard deviations of tuber volume and shape. Compared with the yield traits, the variation for tuber shape was relatively small. The effect of plot shape was minor. With these equations, breeders can determine what plot dimensions are needed to reach the desired precision for each trait.

Synesthesia

People with synesthesia have unusual sensory experiences whereby one stimulus elicits another: Words may evoke tastes, numbers evoke colors, and so on. The eliciting stimulus is called the inducer, whereas the synesthetic experience, which is normally percept-like in quality, is referred to as the concurrent. Synesthetic experiences use some of the same neural substrates as “real” perception. The associations are influenced by cross-modal correspondences between the senses (e.g., high pitch being bright or light) and regularities in one’s own environment. Synesthesia comes in many varieties, but these likely stem from a common cause (because different varieties tend to co-occur together). This is normally explained in terms of an atypical neurodevelopmental cascade from genetic differences that affect brain development and give rise to an atypical profile of behaviors (of which synesthesia is one). People with synesthesia not only have unusual sensory experiences—this being the trait that defines them—but also present with a distinctive cognitive profile (affecting memory, imagery, perception) that has impacts on their life choices (e.g., occupation) and may predispose selectively toward certain clinical vulnerabilities.

Parent-offspring inference in highly inbred populations

Genealogical relationships are fundamental components of genetic studies. However, it is often challenging to infer correct and complete pedigrees even when genome-wide information is available. For example, inbreeding can obfuscate genetic differences between individuals, making it difficult to even distinguish first-degree relatives such as parent-offspring from full siblings. Similarly, genotyping errors can interfere with the detection of genetic similarity between parents and their offspring. Inbreeding is common in natural, domesticated, and experimental populations and genotyping of these populations often has more errors than in human datasets, so efficient methods for building pedigrees under these conditions are necessary. Here, we present a new method for parent-offspring inference in inbred pedigrees called SPORE (Specific Parent-Offspring Relationship Estimation). SPORE is vastly superior to existing pedigree-inference methods at detecting parent-offspring relationships, in particular when inbreeding is high or in the presence of genotyping errors, or both. SPORE therefore fills an important void in the arsenal of pedigree inference tools.

Molecular Classification of Vicia faba L Genotypes by Using RAPD-PCR Markers

The research included the molecular classification study of seven genotypes of the bean Vicia faba L. (FBSPN2, TLD1266, TLD1814, TLB1266, Luzdeotono, favad and Histal. Using the RAPD technique for DNA, as 13 random primers were used, the products of inflation were transferred within the agarose gel, and the results of the study showed the possibility of separating the genotypes from each other and determining the degree of genetic variation between them, as the primers used produced (1002) packages of them (417 normal bundles and (585) mixed bundles. The genetic differences of the studied genotypes were determined to be distinguished by the number of bundles, as they reached (28) bundles, including (13) unique bundles and (15) absent bundles. The ILB1266 genotype showed the highest number of unique bundles, which It reached 4 bundles, while the cultivar Favad showed the absence of unique bundles in it, either bundles are absent. The genotypes (ILD1266, IILB1266, Luzdeotono) were distinguished for having the highest number, which amounted to (3) bundles. As for the FBSPN2 genotype, it did not have any absent bundle, and the primers varied. Of the resulting bundle sizes, their sizes ranged between bp (1925-130), and the highest value for the genetic dimension ranged between (0.110 - 0.269), as the lowest genetic dimension was between the two structures (FBSPN2 and ILD1266), which amounted to 0.110, and the highest value for the genetic dimension was (0.2 69) between the genotypes (ILD1266, HISTAL) (ILD1266, Luzdeotono) The Dendrogram shows the separation of the studied genotypes into two main groups, and each of them into two subgroups.