Genetics

Artificial Selection for Reduced Fitness in Panmictic Populations of Drosophila melanogaster Abstract We investigated the evolution of the panmictic experimental populations of Drosophila melanogaster under the influence of artificial selection for reduced fitness. Slowly developing flies were selected among offspring from parents with low sexual activity and low fecundity. As result of this selection carried out for 16 generations, there was a strong decline in the various components of fitness. Our results confirm the results of the experiments by Kaidanov and his staff. The more rapid decrease in fitness observed by us seems to be due to the use of panmictic populations instead of inbred lines. Thus, the resulting fly selection observed in our studies likely reflects a preexisting genetic variation, rather than new mutations.

Mutations in the Insulin Signaling Pathway Genes Affect Carbohydrate Level under Heat Stress in Drosophila melanogaster Females Abstract The effect of the following insulin signaling pathway genes on carbohydrate content under normal and heat stress conditions in Drosophila melanogaster females is studied: transcription factor Forkhead box class O (dfoxo) and insulin-like peptide DILP6 (dilp6), which is synthesized in the fat body. The hypomorphic mutations dilp641 and foxoBG01018 are shown to result in an increase in glucose and trehalose levels under normal conditions. For the first time, a sharp decline in the expression level of dilp6 and dfoxo genes caused by these mutations is demonstrated not to prevent the increase in the levels of both sugars under heat stress, but reduce the intensity of this response.

Phylogenetic Analysis of Yersinia pestis Strains of the Caucasian Subspecies from the Foci of the Caucasus and Transcaucasia according to the Whole Genome Sequencing Data Abstract We have investigated the population structure of Yersinia pestis spp. caucasica strains from natural plague foci located in the Caucasus and Transcaucasia. According to the data of a whole genome SNP analysis of 28 strains of the Caucasian subspecies, seven of which are sequenced by us, and taking into account 1625 identified core SNPs, the presence of several phylogenetic lines and populations of Yersinia pestis ssp. caucasicacorresponding to the geographical distribution of the strains has been determined. Strains of Y. pestis Caucasian subspecies include three separate clusters, the first of which is represented by strains from the East Caucasian high-mountain plague focus. Their genome has revealed 80 unique SNPs, which indicates their greatest antiquity and the long-standing divergence of this branch from the common stem of the evolution of Caucasian strains. The genomes of strains of two other clusters also differ in a large number of individual SNPs, 32 and 36, respectively. One of them includes strains from the Pre-Sevan mountain, Zangezur-Karabakh mountain, and Pre-Araks low-mountain foci with the grouping within the cluster of three separate subclusters: Pre-Sevan (IIa), Zangezur-Karabakh (IIb), and Zangezur-Karabakh-Pre-Araks (IIc). Another one, the third cluster of the Caucasian subspecies, consists of strains from the northwestern part of the Caucasus highlands (Gyumri and Javakheti-Akhalkalaki foci). Using PCR with hybridization-fluorescent registration of results and whole genome sequencing, two clinical strains of Y. pestis were shown to belong to the Caucasian subtype, which confirms the ability of this subspecies to cause plague in humans.

Relationship of Bovine Lymphocyte Antigen Genes with Clinical Mastitis Disease Using SSCP Technique Abstract BoLA-A and BoLA-DRB3 are in class I and II genes of bovine lymphocyte antigen of immune system respectively which cattle express per haplotype. The aim of this study was to evaluate relationship of BoLA-A and BoLA-DRB3 polymorphisms with clinical mastitis disease using SSCP technique. In the current study, blood sampling was carried out from Holstein cattle (n = 50 susceptible and n = 50 resistant to clinical mastitis) and a random sampling was conducted from Iranian native cattle (Sarabi; n = 50). Amplification of exon 2 of BoLA-DRB3 and BoLA-A genes by specific primers was used for SSCP technique. SSCP technique successfully able to detect some pattern is related to clinical mastitis disease in BoLA-DRB3.2 region as well as genotype pattern of C was observed significantly (P < 0.05) in susceptible Holstein cattle in compared to others pattern. Also, B and Q genotypes patterns of SSCP were detected only in susceptible cattle. Also, SSCP results were showed 17 genotypes pattern in Holstein and 17 different genotypes pattern in Sarabi cattle in BoLA-DRB3.2 gene. Thus, our finding indicated that Sarabi breed comprises completely different allelic in the BoLA-DRB3.2 region compared to Holstein breed. Moreover, results of this study revealed that exon 2 of BoLA-A showed lack of polymorphism in both studied breed. This is the first study on characterization of exon 2 of BoLA-A‎gene using SSCP technique in bovine.‎

Quasi Linkage Equilibrium under Weak Two-Locus Viability Selection: I. Haploid Population with Diallelic Loci Abstract A model of weak viability selection at two diallelic loci with standardization of approaches through the use of perturbation theory is examined. The estimate of the quasi-equilibrium value for the linkage disequilibrium coefficient D is analyzed, and results in terms of average effects in quantitative genetics and in terms of the theory of singular perturbations in mathematics are obtained. The approximation of a discrete-time model of a random mating population with non-overlapping generations under weak selection by ordinary differential equations is considered. Weak selection is considered as a perturbation of the model without selection. The resulting model is singularly perturbed; that is, fast (D) and slow (allele frequencies) variables can be distinguished. The first approximation equation for quasi-equilibrium of D is obtained using the first terms of the Taylor series expansion of the model functions. It coincides with the corresponding part of the system of the first approximation of the asymptotic series for solving singularly perturbed equations. The first approximation for quasi-equilibrium of D is D* = ε(p) \(\frac{\mu }{r}\) x(1 – x) y(1 – y), ε(p) ≡ v11(p) – v12(p) – v21(p) + v22(p), where μ is the intensity of selection, r is the recombination coefficient, ε(p) is the index of epistasis nonadditivity for the viabilities \({{{v}}_{{{{i}_{{\text{1}}}}{{i}_{{\text{2}}}}}}}\) , x and y are the allele frequencies of the first and second locus, respectively. The evolution of a nonequilibrium state of the population actually takes place at quasi-equilibrium (as the result of the stage of fast variable D dynamics) and current values of slow x, y.

A Study on the Effect of Prolactin Gene Variants on Milk Production Traits of Holstein Cattle Abstract Recent studies aiming to improve the daily milk production of cattle using both genetic and environmental factors are extremely important. The aim of this study is to determine the possible relationships between daily milk production and polymorphic distribution of exon 3 region of the prolactin (PRL) gene, which is an important marker for selection. With this purpose, 155 Holstein cows were included in the study, and the demographic data of the cattle were recorded. Venous blood was collected from the jugular vein of cows in 2 tubes of 2 mL each containing EDTA for DNA isolation. Genomic DNA were isolated from these whole blood samples. The prolactin gene region of the cattle were identified using PCR/RFLP and Sanger DNA sequencing method. The genotype, allele frequencies and Hardy–Weinberg equilibrium were calculated using Arlequin version 3.5.1.3 package software. Accordingly, it was found that cows with genotype AA had statistically higher milk yield as compared to those with genotype AB and BB. Missense mutation, frameshift and silent mutations were detected in the prolactin gene exon 3. It was also found that cows with missense mutation had statistically lower milk fat percentage as compared to the others. Consequently, the effects of genotypic distribution and mutation in the prolactin gene on the milk production of Holstein cows, which is a special breed in terms of milk productivity, have been revealed.

Molecular-Genetic Polymorphism of Puccinia triticina in Southern Dagestan Relating to the Center of the Common Evolution between Agent Causing Leaf Rust and Wheat Abstract Intraspecific genetic polymorphism of leaf rust caused by Puccinia triticina Erikss. was evaluated on the basis of the virulence, microsatellite loci (SSR), and single nucleotide polymorphism (SNP) of isolates collected in Southern Dagestan from species of Triticum L. sp. and Aegilops L. sp. Existence of pathogen population differentiation according to the results of virulence and microsatellite analysis indicates the existence of several genetically differing groups of isolates within the Derbent population. Derbent isolates and reference isolates of P. triticina from durum and common wheat that originated from different countries were characterized by a high degree of phylogenetic relationship by SNP markers. Ethiopian durum isolates in contrast were separated in a single clade.

Association between Allelic Variants of IL2 , IL2RA , and IL7R Genes and Multiple Sclerosis Abstract Multiple sclerosis is a chronic progressive disease of nervous system caused by a combination of genetic and environmental factors leading to the development of a complex of autoimmune and neurodegenerative processes. We performed the analysis of association between multiple sclerosis and polymorphic markers of interleukin-2 (IL2), interleukin-2 receptor alpha chain (IL2A) and interleukin-7 receptor alpha chain (IL7R) in the group of Russians, Tatars, and Bashkirs from the Republic of Bashkortostan (N = 1620). In the total study group, we detected the association of IL7R rs10624573*I (OR = 0.79, PBonf = 0.018) and rs1494558*T (OR = 1.44, PBonf = 2.33 × 10–4) variants with multiple sclerosis. When analyzed separately according to the ethnic origin, the association with IL7R rs1494558*T (OR = 1.49, PBonf = 0.005) remained significant in the group of Russians, and the association of IL7R rs10624573*I remained significant in the group of Bashkirs (OR = 0.56, PBonf = 0.02). We performed the multilocus analysis of association using the APSampler algorithm, and found seven combinations of the alleles and/or genotypes of the studied polymorphic loci, significantly associated with multiple sclerosis, most frequently including IL7R rs1494558 and IL7R rs10624573 allelic variants.

Development of Nuclear Microsatellite Markers with Long (Tri-, Tetra-, Penta-, and Hexanucleotide) Motifs for Three Larch Species Based on the de novo Whole Genome Sequencing of Siberian Larch ( Larix sibirica Ledeb.) Abstract Siberian larch (Larix sibirica Ledeb.) is one of the major boreal tree species in Eurasia and has a considerable economic and ecological value. Despite that importance, the development and use of microsatellite markers in this species remain limited. Microsatellite markers are considered to be a valuable tool for estimation of population diversity and structure. Availability of a draft reference assembly of the Siberian larch genome allowed us to identify 1015 microsatellite loci or simple sequence repeats (SSRs) with tri-, tetra-, penta-, and hexanucleotide motifs. For 60 of them PCR primers were designed and tested for amplification in L. sibirica and for their within-genus transferability to L. gmelinii (Rupr.) Rupr. and L. cajanderi Mayr. Here, we present a set of 14 reliable and polymorphic new nuclear SSR markers that can be used for further population genetic studies, breeding programs, and timber origin identification.

An Analysis of the Associations of Polymorphic Variants of the LEPR (rs1137100), LRP5 (rs3736228), and LPL (rs320) Genes with the Risk of Developing Type 2 Diabetes Mellitus Abstract Diabetes mellitus is a hereditary predisposed multifactorial disease. However, the genetic mechanisms of its development have not been fully revealed yet. We conducted a search for associations of polymorphic variants of the LEPR (rs1137100), LRP5 (rs3736228), and LPL (rs320) genes involved in the development of obesity with the development of type 2 diabetes mellitus. The association with development of the disease was established for the T allele of the LRP5 locus (rs3736228) (p = 0.029, OR = 1.46). The rs1137100 locus (p = 0.032) of the LEPR gene was shown to be associated with the body mass index (BMI), but it was not connected with the presence of type 2 diabetes mellitus. Risk markers of development of type 2 diabetes included the T allele of the rs3736228 locus of the LRP5 gene (OR = 1.74, p = 0.012) and the G allele of the rs320 locus of the LPLgene (OR = 1.39, p = 0.027). Statistically significant association was only found in the group of nonobese patients. A decrease in the level of low-density lipoprotein was observed in individuals with the TT genotype of the LPL locus (rs320) (p = 0.04). Individuals with the GT and GG genotypes of this locus had a lower cholesterol level (p = 0.027). A decrease in the level of BMI (p = 0.012) and a decrease in the concentration of triglycerides in the blood (p = 0.00000004) were detected in carriers of the CC genotype of the LRP5 rs3736228 locus.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com