scholarly journals Genetic diversity in global chicken breeds as a function of genetic distance to the wild populations

2020 ◽  
Author(s):  
Dorcus Kholofelo Malomane ◽  
Steffen Weigend ◽  
Armin Otto Schmitt ◽  
Annett Weigend ◽  
Christian Reimer ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Genetic Distance ◽  
Isolation By Distance ◽  
Genetic Distances ◽  
Founder Population ◽  
Wild Populations ◽  
Metabolic Processes ◽  
Evolutionary Forces ◽  
The Relationship

AbstractMigration of populations from their founder population is expected to cause a reduction in genetic diversity and facilitates population differentiation between the populations and their founder population as predicted by the theory of genetic isolation by distance. Consistent with that, a model of expansion from a single founder predicts that patterns of genetic diversity in populations can be well explained by their geographic expansion from the founders, which is correlated to the genetic differentiation. To investigate this in the chicken, we have estimated the relationship between the genetic diversity in 172 domesticated chicken populations and their genetic distances to wild populations. We have found a strong inverse relationship whereby 87.5% of the variation in the overall genetic diversity of domesticated chicken can be explained by the genetic distance to the wild populations. We also investigated if different types of SNPs and genes present similar patterns of genetic diversity as the overall genome. Among different SNP classes, the non-synonymous ones were the most deviating from the overall genome. However, the genetic distances to wild populations still explained more variation in domesticated chicken diversity in all SNP classes ranging from 81.7 to 88.7%. The genetic diversity seemed to change at a faster rate within the chicken in genes that are associated with transmembrane transport, protein transport and protein metabolic processes, and lipid metabolic processes. In general, such genes are flexible to be manipulated according to the population needs. On the other hand, genes which the genetic diversity hardly changes despite the genetic distance to the wild populations are associated with major functions e.g. brain development. Therefore, changes in the genes may be detrimental to the chickens. These results contribute to the knowledge of different evolutionary patterns of different functional genomic regions in the chicken.Author summaryThe chicken was first domesticated about 6000 B.C. in Asia from the jungle fowl. Following domestication, chickens were taken to different parts of the world mainly by humans. Evolutionary forces such as selection and genetic drift have shaped diversification within the chicken species. In addition, new breeds or strains have been developed from crossbreeding programs facilitated by man. These events, together with other breeding practices, have led to genomic alterations causing genetic differentiation between the domesticated chickens and their ancestral/wild population as well as manipulation of the genetic diversity within the domesticated chickens. We investigated the relationship between 172 domesticated chicken populations from different selection, breeding and management backgrounds and their genetic distance to the wild type chickens. We found that the genetic diversity within the populations decreases with the increasing genetic distances to the wild types. Human manipulation of chicken genetic diversity has more effect on the genetic differentiation than simple geographic separations (through migrations) do. We further found that some genes associated with vital functions show evolutionary constraints or persistent selection across the populations and do not comply with this relationship i.e. the genetic diversity within the populations is constant despite the change in the genetic distance to the wild types.

scholarly journals Genetic diversity in global chicken breeds in relation to their genetic distances to wild populations

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Dorcus Kholofelo Malomane ◽  
Steffen Weigend ◽  
Armin Otto Schmitt ◽  
Annett Weigend ◽  
Christian Reimer ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Protein Transport ◽  
Isolation By Distance ◽  
Genetic Distances ◽  
Nucleotide Polymorphisms ◽  
Founder Population ◽  
Wild Populations ◽  
Evolutionary Patterns ◽  
The One

Abstract Background Migration of a population from its founder population is expected to cause a reduction of its genetic diversity and facilitates differentiation between the population and its founder population, as predicted by the theory of genetic isolation by distance. Consistent with that theory, a model of expansion from a single founder predicts that patterns of genetic diversity in populations can be explained well by their geographic expansion from their founders, which is correlated with genetic differentiation. Methods To investigate this in chicken, we estimated the relationship between the genetic diversity of 160 domesticated chicken populations and their genetic distances to wild chicken populations. Results Our results show a strong inverse relationship, i.e. 88.6% of the variation in the overall genetic diversity of domesticated chicken populations was explained by their genetic distance to the wild populations. We also investigated whether the patterns of genetic diversity of different types of single nucleotide polymorphisms (SNPs) and genes are similar to that of the overall genome. Among the SNP classes, the non-synonymous SNPs deviated most from the overall genome. However, genetic distance to the wild chicken still explained more variation in domesticated chicken diversity across all SNP classes, which ranged from 83.0 to 89.3%. Conclusions Genetic distance between domesticated chicken populations and their wild relatives can predict the genetic diversity of the domesticated populations. On the one hand, genes with little genetic variation across populations, regardless of the genetic distance to the wild population, are associated with major functions such as brain development. Changes in such genes may be detrimental to the species. On the other hand, genetic diversity seems to change at a faster rate within genes that are associated with e.g. protein transport and protein and lipid metabolic processes. In general, such genes may be flexible to changes according to the populations’ needs. These results contribute to the knowledge of the evolutionary patterns of different functional genomic regions in the chicken.

scholarly journals GENETIC CHANGE AND RATES OF CLADOGENESIS

Genetics ◽  
1975 ◽  
Vol 81 (4) ◽  
pp. 757-773
Author(s):  
John C Avise ◽  
Francisco J Ayala
Keyword(s):  
Genetic Differentiation ◽  
Genetic Distance ◽  
Genetic Divergence ◽  
Natural Populations ◽  
Genetic Distances ◽  
Genetic Change ◽  
The Other ◽  
Limited Information ◽  
History Of ◽  
The Relationship

ABSTRACT Models are introduced which predict ratios of mean levels of genetic divergence in species-rich versus species-poor phylads under two competing assumptions: (1) genetic differentiation is a function of time, unrelated to the number of cladogenetic events and (2) genetic differentiation is proportional to the number of speciation events in the group. The models are simple, general, and biologically real, but not precise. They lead to qualitatively distinct predictions about levels of genetic divergence depending upon the relationship between rates of speciation and amount of genetic change. When genetic distance between species is a function of time, mean genetic distances in speciose and depauperate phylads of equal evolutionary age are very similar. On the contrary, when genetic distance is a function of the number of speciations in the history of a phylad, the ratio of mean genetic distances separating species in speciose versus depauperate phylads is greater than one, and increases rapidly as the frequency of speciations in one group relative to the other increases. The models may be tested with data from natural populations to assess (1) possible correlations between rates of anagenesis and cladogenesis and (2) the amount of genetic differentiation accompanying the speciation process. The data collected in electrophoretic surveys and other kinds of studies can be used to test the predictions of the models. For this purpose genetic distances need to be measured in speciose and depauperate phylads of equal evolutionary age. The limited information presently available agrees better with the model predicting that genetic change is primarily a function of time, and is not correlated with rates of speciation. Further testing of the models is, however, required before firm conclusions can be drawn.

Ampelographic characterization of white grapevine cul-tivars (Vitis vinifera L.) grown in Palestine

2015 ◽  
Vol 3 (1) ◽  
pp. 1-11
Author(s):  
Rezq Basheer-Salimia
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Germplasm Conservation ◽  
Genetic Distances ◽  
Vitis Vinifera L ◽  
Similarity Matrix ◽  
Breeding Programs ◽  
Local Varieties ◽  
Synonymies And Homonymies

Abstract: In Palestine, grape culture consists of ecotypes and cultivars (also called local varieties), for which a large number of homonymous and synonymous designations exist as well as misnaming of cultivars. The present study is the first report using detailed ampelographic characterizations (39 informative traits) to assess genetic diversity and detect similarities among sixteen accessions collected from putative diverse grape genotypes In general, 30 descriptors presented highly and satisfactory divergent genotypes, whereas the remaining traits showed no or very little ampelographic variation. Based on the similarity matrix and the resulting dendrogram of these ampelographic data, distinguishable genotypes as well as some cases of synonymies and homonymies clearly exist. A synonymy case seemed to be in four genotypes including Jandali-Mfarad, Jan-dali-Mrazraz, Jandali, and Hamadani-Mattar, which indeed showed genetic distances of less than 0.5, sug-gesting their relatedness, and the possibility that they are the same genotype, but with different names. In addition, homonym cases also occur in the following pairs of “Marawi’s, Hamadani’s, and Zaini’s genotypes, in which each pair seems to be two distinctive genotypes. Finally, among the 16 examined genotypes, the Zaini-Baladi genotype tended to show the highest genetic distance values from the others and thus could be potentially incorporated into any further local or regional breeding programs as well as germplasm conservation.

Detection of genetic diversity in rough fescue (Festuca campestris Rydb) populations of southern Alberta and British Columbia, Canada, using RAPD markers

2008 ◽  
Vol 88 (2) ◽  
pp. 307-312
Author(s):  
Zhao Mengli ◽  
Han Bing ◽  
Walter D Willms
Keyword(s):  
Genetic Diversity ◽  
British Columbia ◽  
Genetic Distance ◽  
Random Amplified Polymorphic Dna ◽  
Geographic Distance ◽  
Genetic Distances ◽  
Gene Frequencies ◽  
Southern Alberta ◽  
Potential Adaptation ◽  
Rough Fescue

Mountain rough fescue (Festuca campestris Rydb.) is a tufted native grass in southern Alberta and British Columbia, Canada, and has attracted interest for use in reclamation. However, its seed is often available from only a few localized sources and may not be adapted for areas removed from the collection site. We conducted a study to determine the genetic variability among rough fescue populations to assess its potential adaptation. Thirty plants were collected from each of six populations and analyzed using Random Amplified Polymorphic DNA (RAPD). One population (Kamloops, BC) was separated by several mountain ranges from the five easterly Alberta populations.The Kamloops population was also separated from the Alberta populations by genetic distance in two clusters. Of the total genetic variation present in the data, 21% was found among populations while the remaining (79%) was found within populations. Nei’s genetic distances among populations were related to their geographical distances. Genetic differences among populations appeared to be caused primarily by differences in gene frequencies rather than rare genes. Also, genetic diversity appeared to increase from west to east suggesting that the more easterly populations had greater adaptation potential. We speculate that the more easterly populations are less likely to share genes since the prevailing winds are from the west. Germplasm from the more easterly populations may be used with suitable precautions within Alberta and possibly around Kamloops. Key words: Genetic distance, geographic distance, reclamation, potential adaptation

scholarly journals Population genetic structure and variability in Lindera glauca (Lauraceae) indicates low levels of genetic diversity and skewed sex ratios in natural populations in mainland China

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8304 ◽  
Author(s):  
Biao Xiong ◽  
Limei Zhang ◽  
Shubin Dong ◽  
Zhixiang Zhang
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Isolation By Distance ◽  
Sex Ratios ◽  
Mainland China ◽  
Small Sample ◽  
Chloroplast Microsatellites ◽  
Wild Populations ◽  
Haplotype Networks ◽  
Low Levels

Lindera glauca (Lauraceae) is a tree of economic and ecological significance that reproduces sexually and asexually via apomictic seeds. It is widely distributed in the low-altitude montane forests of East Asia. Despite the potential implications of a mixed reproductive system in terms of genetic diversity, few studies have focused on this aspect. In this study, the genetic structure of wild populations of L. glauca was investigated via genetic analyses. Overall, 13 nuclear microsatellites (nSSRs) and five chloroplast microsatellites (cpSSRs) were used to genotype 300 individual plants, taken from 20 wild populations (a small sample size in some wild populations is due to the limitation of its specific reproduction, leading to certain limitations in the results of this study) and two cultivated populations ranging across nearly the entire natural distribution of mainland China. The populations exhibited low levels of genetic diversity (nSSR: AR = 1.75, Ho = 0.32, He = 0.36; cpSSR: Nb = 2.01, Hrs = 0.40), and no significant effect of isolation by distance between populations existed, regardless of marker type (nSSR: R2 = 0.0401, P = 0.068; cpSSR: R2 = 0.033, P = 0.091). Haplotype networks showed complex relationships among populations, and the H12 haplotype was predominant in most populations. Analyses of molecular variance obtained with nuclear markers (Fsc = 0.293, FST = 0.362) and chloroplast markers (Fsc = 0.299, FST = 0.312) were similar. The migration ratio of pollen flow versus seed flow in this study was negative (r = −1.149). Results suggest that weak barriers of dispersal between populations and/or the similarity of founders shared between neighbors and distant populations are indicative of the gene flow between populations more likely involving seeds. Wild L. glauca in mainland China was inferred to have highly skewed sex ratios with predominant females. In addition, some populations experienced a recent bottleneck effect, especially in Gujianshan, Chongqing, and southwest China (population GJS). It is suggested that few wild male individuals should be conserved in order to maintain overall genetic diversity in the wild populations of this species. These findings provide important information for the sustainable utilization and preservation of the overall genetic diversity of L. glauca.

scholarly journals Genetic Diversity and Population Divergence of a Rare, Endemic Grass (Elymus breviaristatus) in the Southeastern Qinghai-Tibetan Plateau

2019 ◽  
Vol 11 (20) ◽  
pp. 5863 ◽  
Author(s):  
Qingqing Yu ◽  
Qian Liu ◽  
Yi Xiong ◽  
Yanli Xiong ◽  
Zhixiao Dong ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Tibetan Plateau ◽  
Isolation By Distance ◽  
Genetic Distances ◽  
Conservation Strategy ◽  
Conservation Strategies ◽  
Grass Species ◽  
Population Divergence ◽  
High Genetic Diversity ◽  
Widespread Species

Elymus breviaristatus is a grass species only distributed in the southeast of Qinghai-Tibetan Plateau (QTP), which has suffered from serious habitat fragmentation. Therefore, understanding patterns of genetic diversity within and among natural E. breviaristatus populations could provide insight for future conservation strategies. In this study, sequence-related amplified polymorphism markers were employed to investigate the genetic diversity and hierarchical structure of seven E. breviaristatus populations from QTP, China. Multiple measures of genetic diversity indicated that there is low to moderate genetic variation within E. breviaristatus populations, consistent with its presumed mating system. In spite of its rarity, E. breviaristatus presented high genetic diversity that was equivalent to or even higher than that of widespread species. Bayesian clustering approaches, along with clustering analysis and principal coordinate analysis partitioned the studied populations of E. breviaristatus into five genetic clusters. Differentiation coefficients (Fst, GST, etc.) and AMOVA analysis revealed considerable genetic divergence among different populations. BARRIER analyses indicated that there were two potential barriers to gene flow among the E. breviaristatus populations. Despite these patterns of differentiation, genetic distances between populations were independent of geographic distances (r = 0.2197, p = 0.2534), indicating little isolation by distance. Moreover, despite detecting a common outlier by two methods, bioclimatic factors (altitude, annual mean temperature, and annual mean precipitation) were not related to diversity parameters, indicating little evidence for isolation caused by the environment. These patterns of diversity within and between populations are used to propose a conservation strategy for E. breviaristatus.

Genetic differentiation of regional populations of the widespread Asiatic toad (Bufo gargarizans), as revealed by development of novel microsatellite markers

2018 ◽  
Vol 66 (6) ◽  
pp. 335
Author(s):  
T. Pan ◽  
P. Yan ◽  
M. Yang ◽  
H. Wang ◽  
I. Ali ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Genetic Distance ◽  
Yangtze River ◽  
The Yangtze River ◽  
Geographic Scale ◽  
Widespread Species ◽  
Bufo Gargarizans ◽  
Toad Bufo

Dispersal is a key component of a species’ life history, by influencing population persistence, genetic structure, adaptation and maintenance of genetic diversity. The Asiatic toad (Bufo gargarizans) is a widespread species in east Asia. However, we still have no knowledge of what kind of geographical scale equates to genetic differentiation within B. gargarizans. In this study, the population genetics of B. gargarizans was studied at five localities, with the Yangtze River running through the sampling area, in order to detect the level of genetic differentiation and the natural barriers to the species’ dispersal on a small geographic scale, by means of the development and use of novel microsatellite loci. These markers revealed a relatively high level of genetic diversity. Distinct genetic structure among populations in B. gargarizans was observed, as described by genetic distance, AMOVA, PCA and Geneland results. A weak but significant positive correlation between genetic distance and geographical distance. The combination of these findings suggests that the Yangtze River and geographic distance may act as effective barriers for B. gargarizans. These results serve as benchmark data for understanding the impacts of dispersal barriers and continued landscape research on B. gargarizans.

scholarly journals Genetic Diversity Based on ISSR Markers of Apple Genotypes in Ardahan/Turkey

2018 ◽  
Vol 10 (4) ◽  
pp. 554-558
Author(s):  
Emre SEVİNDİK ◽  
Hüseyin UYSAL ◽  
Zehra Tuğba MURATHAN
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Analysis ◽  
Genetic Distance ◽  
Uv Light ◽  
Genetic Relationships ◽  
Issr Markers ◽  
Genetic Distances ◽  
The Matrix ◽  
Commercial Kits ◽  
Issr Primers

Within the present study, it was conducted a genetic diversity analysis using ISSR markers for some apple genotypes grown in Ardahan region, Turkey. Total genomic DNA (gDNA) isolation from apple leaves was performed using commercial kits. Five ISSR primers were used to determine the genetic diversity among the genotypes studied. Polymerase Chain Reaction (PCR) was performed with all gDNA samples to produce bands to score. PCR products were run in agarose gel and visualized under UV light. Bands on the gels were scored as “1”, while no bands at the corresponding positions were scored as “0”, to generate the matrix file. Five ISSR primers produced a total of 35 bands, and 20 of them were polymorphic. The polymorphic bands rated approximately 57%. Phylogenetic relationships and genetic distances between the genotypes were calculated by using the PAUP [Phylogenetic Analysis Using Parsimony (and Other Methods)] program.  According to the PAUP data, the closest genetic distance was 0.03704 between ‘Kaburga’ and ‘Japon Apple’ genotypes, while the furthest genetic distance was 0.48148 between ‘Karanfil Apple’ and ‘Sisli Uruset’. The phylogenetic analysis obtained using UPGMA algorithm produced a phylogenetic tree with two clades. The results suggest that ISSR markers are useful tools for determining genetic relationships among apple genotypes.

Lack of isozyme similarity between Vigna unguiculata and other species of subgenus Vigna (Leguminosae)

1993 ◽  
Vol 71 (4) ◽  
pp. 586-591 ◽  
Author(s):  
R. E. Vaillancourt ◽  
N. F. Weeden
Keyword(s):  
Genetic Distance ◽  
Vigna Unguiculata ◽  
Genetic Distances ◽  
Close Relative ◽  
Tropical Africa ◽  
The Third ◽  
Upgma Cluster Analysis ◽  
Isozyme Loci ◽  
The Relationship ◽  
Nei's Genetic Distance

The cowpea (Vigna unguiculata (L.) Walp.) is an important crop of tropical Africa, Asia, and South America. However, the relationship between the cowpea and other species of subg. Vigna is relatively unknown. The objective of this study was to assess the genetic distance among species of subg. Vigna using isozymes. Twenty-four populations of the cowpea species and 39 populations from 10 other species (at least one species per section of subgenus Vigna) were sampled. Nei's genetic distance was calculated from allelic frequencies at 26 isozyme loci. UPGMA cluster analysis was performed. The range of genetic distance among species of subg. Vigna (0.41 – 2.69) was greater than previously reported in most plant genera. Three clusters of species were apparent. The first cluster included three species of sect. Vigna (V. luteola, V. oblongifolia, and V. subterranea (the Bambara groundnut)). The second cluster grouped together sections Liebrechtsia and Macrodontae. The third cluster included V. unguiculata, V. reticulata, and V. vexillata. The distances between species of this cluster were large and of similar size in all combinations (range from 0.92 to 0.95). None of the species included in this survey can be called a close relative of V. unguiculata. Key words: Vigna, cowpea, isozymes, genetic distances.

Genetic Diversity of Rice vampireweed (Rhamphicarpa fistulosa) Populations in Rainfed Lowland Rice in West Africa

Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 430-440
Author(s):  
Norliette Zossou ◽  
Hubert Adoukonèou-Sagbadja ◽  
Daniel Fonceka ◽  
Lamine Baba-Moussa ◽  
Mbaye Sall ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Lowland Rice ◽  
Rice Grain ◽  
High Genetic Diversity ◽  
Genetic Groups ◽  
Rainfed Lowland ◽  
Rice Genotypes ◽  
The Relationship ◽  
Aflp Technique

Rice vampireweed belongs to the Orobanchaceae and is found in Africa and Australia. It is a hemiparasitic weed of lowland rice genotypes and causes losses of 40 to 100% of rice grain yield. Our study addressed the genetic diversity of rice vampireweed in Benin and Senegal. The specific objectives of this research were to study the genetic diversity of rice vampireweed accessions in Benin and Senegal and the relationship between the different genotypes of rice vampireweed through agroecological areas. To achieve these objectives, the genetic diversity of rice vampireweed accessions using the AFLP technique was studied. Based on our results, dendrogram classification has distinguished four different genetic groups. The populations of Benin and Senegal are genetically diverse. Substantial genetic differentiation (GST) exists among agroecological areas within Benin and Senegal (GST = 0.17). The high genetic diversity of rice vampireweed in Benin and Senegal presents a challenge for the development of resistant rice germplasm.

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