allelic diversity
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2022 ◽  
Author(s):  
Luisa Amo ◽  
Guillermo Amo de Paz ◽  
Johanna Kabbert ◽  
Annie Machordom

MHC genes play a fundamental role in immune recognition of pathogens and parasites. Therefore, females may increase offspring heterozygosity and genetic diversity by selecting MHC genetically compatible or heterozygous males. In birds, several studies suggest that MHC genes play a role in mate choice, and recent evidence suggest that olfaction may play a role in such discrimination. Previous studies indicated that house sparrow females with low allelic diversity prefer males with higher diversity in MHC-I alleles. Here, we directly explored whether both house sparrow females and males could estimate by scent the number in MHC amino acid and functional variants as well as the level of MHC-I similarity or dissimilarity of potential partners. Our results show that neither females nor males exhibit a preference related to the number of MHC-I amino acid variants or functional variants or in relation to MHC amino acid or functional similarity of potential partners, suggesting that MHC-I is not detected through olfaction. Further studies are needed to understand the mechanisms responsible for MHC-I based mate discrimination in birds.


Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 54
Author(s):  
Sofía Sucar ◽  
Martín Federico Carboni ◽  
María Florencia Rey Burusco ◽  
Martín Alfredo Castellote ◽  
Gabriela Alejandra Massa ◽  
...  

Native potatoes are the most diverse among cultivated potato species and thus constitute a valuable source for identifying genes for potato improvement. Nevertheless, high-density mapping, needed to reveal allelic diversity, has not been performed for native Argentinian potatoes. We present a study of the genetic variability and population structure of 96 Andigena potatoes from Northwestern Argentina performed using a subset of 5035 SNPs with no missing data and full reproducibility. These high-density markers are distributed across the genome and present a good coverage of genomic regions. A Bayesian approach revealed the presence of: (I) a major group comprised of most of the Andean accessions; (II) a smaller group containing the out-group cv. Spunta and the sequenced genotype DM; and (III) a third group containing colored flesh potatoes. This grouping was also consistent when maximum likelihood trees were constructed and further confirmed by a principal coordinate analysis. A group of 19 accessions stored as Andean varieties clustered consistently with group Tuberosum accessions. This was in agreement with previous studies and we hypothesized that they may be reintroductions of European-bred long day-adapted potatoes. The present study constitutes a valuable source for allele mining of genes of interest and thus provides a tool for association mapping studies.


2021 ◽  
pp. 330-335
Author(s):  
В.И. Рисованная ◽  
С.М. Гориславец ◽  
François Lefort

Представлены результаты оценки генетического разнообразия 24 местных сортов юга России, поддерживаемых на ампелографической коллекции ФГБУН «ВННИИВиВ «Магарач». ДНК-типирование сортов и оценка аллельного разнообразия выполнено с использованием 9 ядерных (nSSR) и 3 хлоропластных (cpSSR) микросателлитных локусов. Уровень полиморфизма nSSR локусов составил 100 %. Всего было идентифицировано 73 аллеля, в среднем 9.1 аллеля /локус. Минимальное количество аллелей идентифицировано в локусах ssrVrZAG64 и ssrZag83. Наибольшее количество аллелей выявлено в локусе ssrVvUCH29 (13 аллелей), диапазон размера которых составил 203 п.н. - 309 п.н. В результате анализа полиморфизма сpSSR-локусов идентифицировано 4 хлоротипа: А, В, С, D. Наиболее распростанен в группе изученных сортов хлоротип D (58 %). В статье обсуждается происхождение сортов на основе анализа их гаплотипов. По результатами анализа аллельного полиморфизма nSSR-локусов рассчитана матрица генетических дистанций, значения которой находились в диапазоне 0,33-0,94, построена дендрограмма, отражающая взаимоотношения между образцами. По степени генетического сходства выделились 3 основных кластера, в которых наблюдалась дифференциация или тенденция к дифференциации по эколого-географическим группам. The assessment results of genetic diversity of 24 local varieties of the South of Russia, maintained in the ampelographic collection of the FSBSI Institute Magarach are presented. DNA typing of cultivars and assessment of allelic diversity was performed using 9 nuclear (nSSR) and 3 chloroplast (cpSSR) microsatellite loci. The level of polymorphism of nSSR loci was 100%. A total of 73 alleles were identified with an average of 9.1 alleles per locus. The minimal number of alleles was observed in the ssrVrZAG64 and ssrZag83 loci. The biggest number of alleles was found in the ssrVvUCH29 locus (13 alleles), the size range of which was 203 bp-309 bp. As a result of polymorphism analysis of cpSSR loci, 4 chlorotypes were identified: A, B, C, D. Chlorotype D is the most widespread in the group of the studied cultivars (58%). The article discusses the origin of varieties based on the analysis of their haplotypes. Based on the results of the analysis of allelic polymorphism of nSSR loci, a matrix of genetic distances was calculated, the values of which were in the range of 0.33-0.94, and a dendrogram, reflecting the relationship between the samples, was constructed. According to the degree of genetic similarity, 3 main clusters were distinguished, in which differentiation or a tendency towards differentiation by ecological-geographical groups was observed.


2021 ◽  
Author(s):  
Jack M. Fu ◽  
F. Kyle Satterstrom ◽  
Minshi Peng ◽  
Harrison Brand ◽  
Ryan L. Collins ◽  
...  

Individuals with autism spectrum disorder (ASD) or related neurodevelopmental disorders (NDDs) often carry disruptive mutations in genes that are depleted of functional variation in the broader population. We build upon this observation and exome sequencing from 154,842 individuals to explore the allelic diversity of rare protein-coding variation contributing risk for ASD and related NDDs. Using an integrative statistical model, we jointly analyzed rare protein-truncating variants (PTVs), damaging missense variants, and copy number variants (CNVs) derived from exome sequencing of 63,237 individuals from ASD cohorts. We discovered 71 genes associated with ASD at a false discovery rate (FDR) ≤ 0.001, a threshold approximately equivalent to exome-wide significance, and 183 genes at FDR ≤ 0.05. Associations were predominantly driven by de novo PTVs, damaging missense variants, and CNVs: 57.4%, 21.2%, and 8.32% of evidence, respectively. Though fewer in number, CNVs conferred greater relative risk than PTVs, and repeat-mediated de novo CNVs exhibited strong maternal bias in parent-of-origin (e.g., 92.3% of 16p11.2 CNVs), whereas all other CNVs showed a paternal bias. To explore how genes associated with ASD and NDD overlap or differ, we analyzed our ASD cohort alongside a developmental delay (DD) cohort from the deciphering developmental disorders study (DDD; n=91,605 samples). We first reanalyzed the DDD dataset using the same models as the ASD cohorts, then performed joint analyses of both cohorts and identified 373 genes contributing to NDD risk at FDR ≤ 0.001 and 662 NDD risk genes at FDR ≤ 0.05. Of these NDD risk genes, 54 genes (125 genes at FDR ≤ 0.05) were unique to the joint analyses and not significant in either cohort alone. Our results confirm overlap of most ASD and DD risk genes, although many differ significantly in frequency of mutation. Analyses of single-cell transcriptome datasets showed that genes associated predominantly with DD were strongly enriched for earlier neurodevelopmental cell types, whereas genes displaying stronger evidence for association in ASD cohorts were more enriched for maturing neurons. The ASD risk genes were also enriched for genes associated with schizophrenia from a separate rare coding variant analysis of 121,570 individuals, emphasizing that these neuropsychiatric disorders share common pathways to risk.


Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1897
Author(s):  
Alina Berezhnaya ◽  
Antonina Kiseleva ◽  
Irina Leonova ◽  
Elena Salina

Heading time is an important agronomic trait affecting the adaptability and productivity of common wheat. In this study, 95 common wheat varieties from Russia and the late-maturing breeding line ‘Velut’ were tested for allelic diversity of genes having the strongest effect on heading. In this research, allelic variation at the Ppd-D1, Vrn-A1, Vrn-B1, Vrn-D1, and Vrn-B3 loci was tested. The Vrn-B1 and Vrn-B3 loci provided the largest contribution to genetic diversity. We found two novel allelic variants of the Vrn-B3 gene in the studied varieties. Ten varieties carried a 160 bp insertion in the promoter region, and the breeding line ‘Velut’ carried a 1617 bp insertion. These alleles were designated Vrn-B3e and Vrn-B3d, respectively. The analysis of the sequences showed the recent insertion of a retrotransposon homologous to the LTR retrotransposon (RLX_Hvul_Dacia_ RND-1) in the Vrn-B3d allele. Plants with the Vrn-B3e and the ‘Velut’ line with the Vrn-B3d allele headed later than the plants with the wild-type allele; among these plants, ‘Velut’ is the latest maturing wheat variety. Analysis of the gene expression of two groups of lines differing by the Vrn-B3 alleles (Vrn-B3d or vrn-B3) from the F2 population with ‘Velut’ as a parental line did not reveal a significant difference in the expression level between the groups. Additional research is required to study the reasons for the late maturation of the ‘Velut’ line. However, the studied wheat varieties could be used as a potential source of natural variation in genes controlling heading times.


2021 ◽  
pp. 1-10
Author(s):  
Shubham Loat ◽  
Namita Kumari ◽  
Shallu Saini ◽  
M. S. Dige ◽  
Anurag Kumar ◽  
...  

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Julissa J. Sánchez-Velásquez ◽  
Lorenzo E. Reyes-Flores ◽  
Carmen Yzásiga-Barrera ◽  
Eliana Zelada-Mázmela

Abstract Objective The advancement of molecular techniques in an era in which high-throughput sequencing has revolutionized biology renders old-fashioned alternatives to high-throughput methods obsolete. Such advanced molecular techniques, however, are not yet accessible to economically disadvantaged region-based laboratories that still obtain DNA profiles using gel-based techniques. To explore whether cost-efficient techniques can produce results that are as robust as those obtained using high-throughput methods, we compared the performance of polyacrylamide gel electrophoresis (PAGE)- and capillary electrophoresis (CE)-derived genomic data in estimating genetic diversity and inferring relatedness using 70 individuals of fine flounder (Paralichthys adspersus) selected from a hatchery population and genotyped for five microsatellite loci. Results Here, we show that PAGE- and CE-derived genomic datasets yield comparable genetic diversity levels regarding allelic diversity measures and heterozygosity. However, relatedness inferred from each dataset showed that the categorization of dyads in the different relationship categories strongly differed. This suggests that while scientists can reliably use PAGE-derived genomic data to estimate genetic diversity, they cannot use the same for parentage testing. The findings could help laboratories committed to population research not be discouraged from using the PAGE system if high-throughput technologies are unavailable and the method is adequate to address the biological question.


Author(s):  
Denise Patricia Mawili-Mboumba ◽  
Marie Louise Tshibola Mbuyi ◽  
Noe Patrick M’bondoukwe ◽  
Marielle Karine Bouyou-Akotet

Background: To perform molecular epidemiologic studies based on large cohorts, material such as RDTs or filter papers are useful for biological sample collection and extraction of RNA or DNA of good quality. Thus, we aimed to assess the quality of DNA extracted from malaria rapid diagnostic tests (RDTs) stored at various temperatures for the analysis of Plasmodium falciparum genetic diversity. Methods: Febrile patients benefitted from free malaria diagnosis using microscopy in a malaria sentinel site, at the Regional Hospital Estuaire-Melen, in Gabon, in 2015. P. falciparum isolates were collected onto one filter paper and 2 similar RDTs devices (Acon®) per patient. Nucleic acids were extracted with QiAmp Qiagen kit from paper and RDTs and the quality of the DNA was analyzed by msp1 gene amplification. Results: Msp1gene amplification was achieved in nucleic acids extracted from all filter papers and RDTs devices (n = 45, 100%). K1 alleles were detected in 93.3% (n = 42/45) of the samples and Mad20 alleles in 73.3% (n = 33/45). The number and the intensity of K1 and/or Mad20 fragments were comparable according to the sample collection material and the storage conditions (room temperature vs -20°C) of the samples. The size of the fragments indicating allelic diversity was comparable in 80% (n=36) of the samples. Conclusion: These data show that RDTs are a valuable source of DNA for malaria parasite genetic polymorphism analysis. Storage conditions of the devices did not influence the quality of DNA extracted from RDTs device, although some alleles may be missed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christopher Setzke ◽  
Carmen Wong ◽  
Michael A. Russello

AbstractHistorical DNA analysis of archival samples has added new dimensions to population genetic studies, enabling spatiotemporal approaches for reconstructing population history and informing conservation management. Here we tested the efficacy of Genotyping-in-Thousands by sequencing (GT-seq) for collecting targeted single nucleotide polymorphism genotypic data from archival scale samples, and applied this approach to a study of kokanee salmon (Oncorhynchus nerka) in Kluane National Park and Reserve (KNPR; Yukon, Canada) that underwent a severe 12-year population decline followed by a rapid rebound. We genotyped archival scales sampled pre-crash and contemporary fin clips collected post-crash, revealing high coverage (> 90% average genotyping across all individuals) and low genotyping error (< 0.01% within-libraries, 0.60% among-libraries) despite the relatively poor quality of recovered DNA. We observed slight decreases in expected heterozygosity, allelic diversity, and effective population size post-crash, but none were significant, suggesting genetic diversity was retained despite the severe demographic contraction. Genotypic data also revealed the genetic distinctiveness of a now extirpated population just outside of KNPR, revealing biodiversity loss at the northern edge of the species distribution. More broadly, we demonstrated GT-seq as a valuable tool for collecting genome-wide data from archival samples to address basic questions in ecology and evolution, and inform applied research in wildlife conservation and fisheries management.


2021 ◽  
Author(s):  
Roman Stetsenko ◽  
Thomas Brom ◽  
Vincent Castric ◽  
Sylvain Billiard

The self-incompatibility locus (S-locus) of flowering plants displays a striking allelic diversity. How such a diversity has emerged remains unclear. In this paper, we performed numerical simulations in a finite island population genetics model to investigate how population subdivision affects the diversification process at a S-locus, given that the two-genes architecture typical of S-loci involves the crossing of a fitness valley. We show that population structure increases the number of self-incompatibility haplotypes (S-haplotypes) maintained in the whole metapopulation, but at the same time also slightly reduces the parameter range allowing for their diversification. This increase is partly due to a reinforcement of the diversification and replacement dynamics of S-haplotypes within and among demes. We also show that the two-genes architecture leads to a higher diversity compared with a simpler genetic architecture where new S-haplotypes appear in a single mutation step. We conclude that population structure helps explain the large allelic diversity at the self-incompatibility locus. Overall, our results suggest that population subdivision can act in two opposite directions: it makes easier S-haplotypes diversification but increases the risk that the SI system is lost.


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