scholarly journals GENETIC VARIATION AND THE ECOLOGICAL PARAMETER "FOOD MEDIUM" IN CAGE POPULATIONS OF DROSOPHILA MELANOGASTER

1976 ◽  
Vol 18 (2) ◽  
pp. 379-383 ◽  
Author(s):  
S. Alahiotis
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Genetic Variants ◽  
Gene Pool ◽  
Ecological Factor ◽  
Common Gene ◽  
Enzyme Loci ◽  
Ecological Parameter ◽  
Food Medium

Impressive effects of the ecological factor "food medium" upon the frequencies of the lethal-bearing second chromosomes in Drosophila melanogaster were found in cage populations originated from a common gene pool. Allozyme frequencies for two second enzyme loci were also determined. The lethal frequencies found were higher when the environment was restrictive than when it was favorable. Moreover, the lethal frequencies were higher in populations of smaller size than in those of greater. The role of the lethal genetic variants in the structure of populations is discussed.

scholarly journals INDUCTION OF GENE POOL DIFFERENTIATION IN DROSOPHILA MELANOGASTER

1978 ◽  
Vol 20 (2) ◽  
pp. 265-273 ◽  
Author(s):  
S. Alahiotis ◽  
M. Pelecanos
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Differentiation ◽  
Environmental Factor ◽  
Gene Pool ◽  
Selective Effect ◽  
Ecological Parameter ◽  
Food Medium ◽  
Large Groups

The selective effect of the ecological parameter "food medium" upon the gene pool of Drosophila melanogaster was investigated in nine cage populations by estimating the allozyme frequencies of the a-Gpdh and Adh loci. The differentiation observed was found to depend dramatically upon the action of the above mentioned environmental factor. Small differences may be mainly attributed to the effect of the differing genetic backgrounds of each gene pool. When the environment was restrictive, a dramatic gene pool differentiation was observed. A discussion is provided bearing upon the observed induction of a process which involves large groups of coadapted genes upon which selection actually acts. Furthermore, the role of nutrition, and especially yeast, was found to have a profound effect upon the observed genetic differentiation of the gene pool of D. melanogaster.

scholarly journals Genetic Differentiation of the Two Types of Polish Cold-blooded Horses Included in the National Conservation Program

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 542
Author(s):  
Artur Gurgul ◽  
Igor Jasielczuk ◽  
Ewelina Semik-Gurgul ◽  
Klaudia Pawlina-Tyszko ◽  
Tomasz Szmatoła ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Molecular Markers ◽  
Genetic Differentiation ◽  
Gene Pool ◽  
Population Variation ◽  
Horse Population ◽  
Current Role ◽  
Conservation Program ◽  
Conservation Breeding

The current role of the horse as a companion animal resulted in a decrease of interest in breeding and usage of draft horses. This meant that the population of cold-blooded horses in Poland has been dramatically reduced during the last decades. To avoid impoverishment of the gene pool of the local horse population, a conservation program was established which involves draft horses and other local horse breeds. The draft horses bred in Poland can be subdivided in a few horse types of which the most widespread and consolidated are Sztumski and Sokólski horses. These two subpopulations are phenotypically diversified, however, the overall level of their genetic differentiation seems to be relatively low and not precisely determined, especially with the use of molecular markers. In reference to this, in this study we used Illumina genotyping arrays to describe in detail the genetic differentiation of these two cold-blooded horse populations. We describe the genetic distance between them, as well as within-population variation, admixture patterns, and level of relatedness within populations. We also made an attempt to detect genome regions divergently selected between those horses by the detection of diversifying selection signals. The results of this study provide initial evidence supporting breeding decisions that were made during conservation breeding program design and answer questions raised by the breeders of Sokólski and Sztumski horses concerning the level of their genetic variation and differentiation.

scholarly journals A CONTRIBUTION TO THE STUDY OF LINKAGE DISEQUILIBRIUM IN DROSOPHILA MELANOGASTER

1976 ◽  
Vol 18 (4) ◽  
pp. 739-745 ◽  
Author(s):  
S. Alahiotis ◽  
M. Pelecanos ◽  
A. Zacharopoulou
Keyword(s):  
Drosophila Melanogaster ◽  
Linkage Disequilibrium ◽  
Natural Population ◽  
Environmental Conditions ◽  
Gene Pool ◽  
Ecological Factors ◽  
Random Drift ◽  
Different Populations ◽  
Food Medium

Linkage disequilibrium was detected in 12 out of 30 cases involving gene alleles and inversions in three cage populations and in a natural population of Drosophila melanogaster from Greece. The cage populations possessed practically the same gene pool at their origin and were maintained simultaneously under the effects of the ecological factors "food medium" and "humidity". It is discussed that the correlation of the same direction found between the frequencies of nonallelic elements of Adh locus and In(2L)22D-34A or In(2R)52A-56F in such different populations as American, Japanese (Mukai et al., 1971, 1974; Langley et al., 1974) and Greek, as well as cage populations under different environmental conditions, could be attributed to the effect of epistatic selection. Moreover, it seems that the In(2L)22D-34A has a tendency to interact genetically with the α-Gpdh locus, particularly when the populations are maintained under crowding conditions. However, further data are needed to assess whether other cases of the observed nonrandom associations can be better explained as transient associations generated by random drift, or as the result of epistatic selection.

Behavioral and Cytogenetic Analysis of the cacophony Courtship Song Mutant and Interacting Genetic Variants in Drosophila melanogaster

Genetics ◽  
1987 ◽  
Vol 115 (3) ◽  
pp. 461-475
Author(s):  
Shankar J Kulkarni ◽  
Jeffrey C Hall
Keyword(s):  
Drosophila Melanogaster ◽  
Locomotor Activity ◽  
Genetic Variants ◽  
Distal Part ◽  
Courtship Song ◽  
Wild Type ◽  
Lethal Mutations ◽  
Complex Interactions ◽  
Chromosomal Breakpoints

ABSTRACT The courtship song of a Drosophila melanogaster male consists of tone pulses interspersed with humming sounds. An X chromosomal mutation, cacophony (cac), causes the production of polycyclic pulses readily distinguishable from those in wild type, which are mono- or bicyclic. Yet, courtship hums and flight wing beats are normal in this mutant, suggesting a specific role of the cac gene in the neural program underlying one particular feature of the fly's wing vibrations. A precise cytogenetic localization of cac is presented; this was obtained by uncovering the song abnormality with deletions that are missing all or the distal part of region 11A; the flies tested were diplo-X adults that had been turned into males by the transformer mutation. Duplications including distal 11A covered cac. The possibility of behavioral specificity for cac's effects was examined by screening a variety of sexual and nonsexual behaviors; these experiments included tests of flies in which the mutation was uncovered by a small deletion. We conclude that cac causes only a limited array of well-defined defects: longer and louder tone pulses in the song and depressed locomotor activity. Further complementation tests involving cac and other closely linked genetic variants-the night-blind-A (nbA) visual mutation, l(1) L13 lethal mutations, and a series of X chromosomal breakpoints-suggested complex interactions among these factors: the breakpoints uncover all three types of mutations; cac and nbA appear to be alleles of l(1)L13, whereas the two behavioral mutations complement each other

scholarly journals Impact of rare and common genetic variation in the Interleukin-1 pathway on human cytokine responses

2020 ◽  
Author(s):  
Rosanne C. van Deuren ◽  
Peer Arts ◽  
Giulio Cavalli ◽  
Martin Jaeger ◽  
Marloes Steehouwer ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genetic Variants ◽  
Rare Variants ◽  
Common Genetic Variation ◽  
Common Variants ◽  
Healthy Individuals ◽  
Cytokine Responses ◽  
Human Cytokine

ABSTRACTBackgroundInterleukin(IL)-1 signaling is of major importance in human innate cytokine responses. Common variants in related genes have been linked to various inflammation-mediated diseases and stimulation-induced cytokine responses, but the role of rare variants remains to be elucidated.MethodsIn this study, we characterize the role of rare and common genetic variation, as identified by molecular inversion probe-based sequencing, in 48 genes related to the IL-1 pathway. Using a systems biology approach, we examined the inter-individual variability of in vitro stimulation-specific human cytokine responses from 463 healthy individuals of the Human Functional Genomics Project and assessed the role of rare and common genetic variants, separately and combined, by means of the Sequence Kernel Association Test.ResultsWe identified strong associations for rare genetic variants in NCF4 (adjP=7.2E−05) and CASP1 (adjP=3.0E−05) with IL-6 production in response to PHA and LPS stimulation, respectively. In addition, common variants in IL36A and IL38 were associated to both C. albicans-induced IL-1β (IL36AadjP=0.0442; IL38adjP=0.0092) and IL-6 production (IL36AadjP=0.0037; IL38adjP=0.0082), an effect that was stronger at the subpathway level both for IL-1β (adjP=0.0017) and IL-6 (adjP=1.8E−04). The common variant signature for the IL-1β and IL-6 response to C. albicans was confirmed by an association with all anti-inflammatory genes (adjP=1.87E−03 and adjP=5.75E−04), and we validated this finding for non-coding common variants. Lastly, we identified a burden of rare variants in pro-inflammatory genes and LPS-induced IL-6 production (adjP=2.42E−04), and a new role for anti-inflammatory rare variants on S. aureus-stimulated IL-6 production (adjP=6.71E−03).ConclusionsIn conclusion, we show that both common and rare genetic variation in genes of the IL-1 pathway, separately and combined, differentially influence in vitro cytokine responses to various stimuli in healthy individuals. This study therefore accentuates potential mechanisms that are translatable into new hypothesis-driven characterization of common and rare variant involvement in a wide variety of inflammatory and immunological mechanisms and diseases.

scholarly journals Evolutionary genetics of Drosophila melanogaster immunity: role of the X chromosome and sex-specific dominance

2020 ◽  
Author(s):  
Manas Geeta Arun ◽  
Amisha Agarwala ◽  
Jigisha ◽  
Mayank Kashyap ◽  
Saudamini Venkatesan ◽  
...  
Keyword(s):  
Immune Response ◽  
Sex Differences ◽  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
X Chromosome ◽  
Evolutionary Genetics ◽  
Systemic Infection ◽  
Population Level ◽  
Sexual Antagonism

AbstractIntralocus Sexual Conflict (IaSC) ensues when males and females of the same species experience divergent selection on shared traits. A large number of traits have been implicated in IaSC and there is growing evidence for sexual antagonism associated with immunity. X chromosomes are thought to be hotspots of sexually antagonistic genetic variation and have been shown to harbour substantial immunity-related genetic variation.Here, using interpopulation crosses and cytogenetic cloning, we investigated the role of the X chromosome in improved immune response of laboratory populations of the fruit-fly Drosophila melanogaster selected against systemic infection by Pseudomonas entomophila.We could not detect any contribution of the X chromosome in the evolved immune response of our selected populations. However, we found strong evidence of sex-specific dominance related to immunity in our populations. Our results indicate that alleles that confer a superior immune response to the selected populations are, on average, partially dominant in females but partially recessive in males.We argue that sex-specific dominance over immunity evolved as a by-product of sexually antagonistic selection in the wild ancestors of our populations. We also highlight sex-specific dominance as a potential mechanism of sex differences in immunity, with population-level sex differences primarily driven by sex differences in heterozygotes.

Genetic background of cholesterol absorption efficacy. The role of Niemann–Pick C1-like 1 receptor and its genetic variation in lipid metabolism

2010 ◽  
Vol 151 (34) ◽  
pp. 1376-1383 ◽  
Author(s):  
Mariann Harangi ◽  
István Balogh ◽  
János Harangi ◽  
György Paragh
Keyword(s):  
Genetic Variation ◽  
Lipid Metabolism ◽  
Genetic Background ◽  
Cholesterol Absorption ◽  
Niemann Pick

A Niemann–Pick C1-like-1 egy szterolfelismerő domént tartalmazó membránfehérje, amelyet nagy számban expresszálnak csúcsi felszínükön a bélhámsejtek. Az utóbbi évek vizsgálatai azt igazolták, hogy ez a fehérje szükséges a szabad koleszterin bejutásához a bélhámsejtekbe a bél lumenéből. Biokémiai vizsgálatok azt igazolták, hogy a Niemann–Pick C1-like-1-hez kötődik az ezetimib, amely egy hatékony koleszterinfelszívódást gátló szer. A bélből történő koleszterinfelszívódás ütemében és az ezetimibkezelés hatékonyságában tapasztalt egyéni eltérések hátterében felmerült néhány Niemann–Pick C1-like-1 génvariáció oki szerepe.

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