scholarly journals Genome-Wide Linkage Disequilibrium and the Extent of Effective Population Sizes in Six Chinese Goat Populations Using a 50K Single Nucleotide Polymorphism Panel

Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 350 ◽  
Author(s):  
Haile Berihulay ◽  
Rabiul Islam ◽  
Lin Jiang ◽  
Yuehui Ma
Keyword(s):  
Linkage Disequilibrium ◽  
Genetic Parameter ◽  
Genetic Selection ◽  
Chromosome 1 ◽  
Effective Population ◽  
Genome Wide ◽  
Population Sizes ◽  
Trait Locus ◽  
D Values ◽  
Genome Wide Linkage Disequilibrium

Genome-wide linkage disequilibrium is a useful parameter to study quantitative trait locus (QTL) mapping and genetic selection. In many genomic methodologies, effective population size is an important genetic parameter because of its relationship to the loss of genetic variation, increases in inbreeding, the accumulation of mutations, and the effectiveness of selection. In this study, a total of 193 individuals were genotyped to assess the extent of LD and Ne in six Chinese goat populations using the SNP 50K BeadChip. Across the determined autosomal chromosomes, we found an average of 0.02 and 0.23 for r2 and D’ values, respectively. The average r2 between all the populations varied little and ranged from 0.055 r2 for the Jining Grey to 0.128 r2 for the Guangfeng, with an overall mean of 0.083. Across the 29 autosomal chromosomes, minor allele frequency (MAF) was highest on chromosome 1 (0.321) and lowest on chromosome 25 (0.309), with an average MAF of 0.317, and showing the lowest (25.5% for Louping) and highest (28.8% for Qingeda) SNP proportions at MAF values > 0.3. The inbreeding coefficient ranged from 0.064 to 0.085, with a mean of 0.075 for all the autosomes. The Jining Grey and Qingeda populations showed higher Ne estimates, highlighting that these animals could have been influenced by artificial selection. Furthermore, a declining recent Ne was distinguished for the Arbas Cashmere and Guangfeng populations, and their estimated values were closer to 64 and 95, respectively, 13 generations ago, which indicates that these breeds were exposed to strong selection. This study provides an insight into valuable genetic information and will open up the opportunity for further genomic selection analysis of Chinese goat populations.

scholarly journals Evaluation of Linkage Disequilibrium, Effective Population Size and Haplotype Block Structure in Chinese Cattle

Animals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 83 ◽  
Author(s):  
Lei Xu ◽  
Bo Zhu ◽  
Zezhao Wang ◽  
Ling Xu ◽  
Ying Liu ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Genomic Selection ◽  
Haplotype Block ◽  
Block Structure ◽  
Effective Population ◽  
Chinese Cattle ◽  
Genome Wide ◽  
Population Sizes ◽  
Haplotype Block Structure ◽  
Selection For

Understanding the linkage disequilibrium (LD) across the genome, haplotype structure, and persistence of phase between breeds can enable us to appropriately design and implement the genome-wide association (GWAS) and genomic selection (GS) in beef cattle. We estimated the extent of genome-wide LD, haplotype block structure, and the persistence of phase in 10 Chinese cattle population using high density BovinHD BeadChip. The overall LD measured by r2 between adjacent SNPs were 0.60, 0.67, 0.58, 0.73, and 0.71 for South Chinese cattle (SCHC), North Chinese cattle (NCC), Southwest Chinese cattle (SWC), Simmental (SIM), and Wagyu (WAG). The highest correlation (0.53) for persistence of phase across groups was observed for SCHC vs. SWC at distances of 0–50 kb, while the lowest correlation was 0.13 for SIM vs. SCHC at the same distances. In addition, the estimated current effective population sizes were 27, 14, 31, 34, and 43 for SCHC, NCC, SWC, SIM, and WAG, respectively. Our result showed that 58K, 87K, 95K, 52K, and 52K markers were required for implementation of GWAS and GS in SCHC, NCC, SWC, SIM, and WAG, respectively. Also, our findings suggested that the implication of genomic selection for multipopulation with high persistence of phase is feasible for Chinese cattle.

Genome-wide linkage disequilibrium and past effective population size in three Korean cattle breeds

2016 ◽  
Vol 48 (1) ◽  
pp. 85-89 ◽  
Author(s):  
P. Sudrajad ◽  
D. W. Seo ◽  
T. J. Choi ◽  
B. H. Park ◽  
S. H. Roh ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Population Size ◽  
Effective Population Size ◽  
Effective Population ◽  
Korean Cattle ◽  
Cattle Breeds ◽  
Genome Wide ◽  
Genome Wide Linkage Disequilibrium

scholarly journals Estimates of linkage disequilibrium and effective population sizes in Chinese Merino (Xinjiang type) sheep by genome-wide SNPs

2017 ◽  
Vol 39 (7) ◽  
pp. 733-745 ◽  
Author(s):  
Shudong Liu ◽  
Sangang He ◽  
Lei Chen ◽  
Wenrong Li ◽  
Jiang Di ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Effective Population ◽  
Genome Wide ◽  
Population Sizes

Genome-wide linkage disequilibrium in two Japanese beef cattle breeds

2006 ◽  
Vol 37 (2) ◽  
pp. 139-144 ◽  
Author(s):  
M. Odani ◽  
A. Narita ◽  
T. Watanabe ◽  
K. Yokouchi ◽  
Y. Sugimoto ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Beef Cattle ◽  
Cattle Breeds ◽  
Genome Wide ◽  
Beef Cattle Breeds ◽  
Genome Wide Linkage Disequilibrium

scholarly journals Incorporating genetic selection into individual-based models (IBMs) of malaria and other infectious diseases

2019 ◽  
Author(s):  
Ian M. Hastings ◽  
Raman Sharma
Keyword(s):  
Control Strategies ◽  
Genetic Parameter ◽  
Genetic Selection ◽  
Wait Time ◽  
Antimicrobial Drug Resistance ◽  
Infinite Population ◽  
Individual Based Models ◽  
Population Sizes ◽  
Human Infections ◽  
The Impact

AbstractOptimal control strategies for human infections are often investigated by computational approaches using individual-based models (IBMs). These typically track humans and evaluate the impact of control interventions in terms of human deaths, clinical cases averted, interruption of transmission etc. Genetic selection can be incorporated into these IBMs and used to track the spread of mutations whose origin and spread are often driven by the intervention, and which subsequently undermine the control strategy; for example, mutations which encode antimicrobial drug resistance or diagnosis- or vaccine-escape phenotypes. Basic population genetic descriptions of selection are based on infinite population sizes (so that chance fluctuations in allele frequency are absent) but IBMs track finite population sizes. We describe how the finite sizes of IBMs affect simulating the dynamics of genetic selection and how best to incorporate genetic selection into these models. We use the OpenMalaria IBM of malaria as an example, but the same principles apply to IBMs of other diseases. We identify four strategies to incorporate selection into IBMs and make the following four recommendations. Firstly, calculate and report the selection coefficients, s, of the advantageous allele as the key genetic parameter. Secondly, use these values of ‘s’ to calculate the wait-time until a mutation successful establishes itself in the population. The wait time for the mutation can be added to speed of selection, s, to calculate when the mutation will reach significant, operationally important levels. Thirdly, quantify the ability of the IBM to robustly estimate small selection coefficients. Fourthly, optimise computational efficacy: when ‘s’ is small it is plausible that fewer replicates of larger IBMs will be more efficient than a larger number of replicates of smaller size.

scholarly journals Extent of genome-wide linkage disequilibrium in Australian Holstein-Friesian cattle based on a high-density SNP panel

BMC Genomics ◽  
2008 ◽  
Vol 9 (1) ◽  
pp. 187 ◽  
Author(s):  
Mehar S Khatkar ◽  
Frank W Nicholas ◽  
Andrew R Collins ◽  
Kyall R Zenger ◽  
Julie AL Cavanagh ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
High Density ◽  
Genome Wide ◽  
Holstein Friesian ◽  
Snp Panel ◽  
Friesian Cattle ◽  
Genome Wide Linkage Disequilibrium

scholarly journals Gene duplication confers enhanced expression of 27-kDa γ-zein for endosperm modification in quality protein maize

2016 ◽  
Vol 113 (18) ◽  
pp. 4964-4969 ◽  
Author(s):  
Hongjun Liu ◽  
Junpeng Shi ◽  
Chuanlong Sun ◽  
Hao Gong ◽  
Xingming Fan ◽  
...  
Keyword(s):  
Linkage Mapping ◽  
Genome Wide Association Study ◽  
Genetic Selection ◽  
Quality Protein Maize ◽  
Genome Wide ◽  
Mapping Analysis ◽  
Enhanced Expression ◽  
Selection For ◽  
Trait Locus ◽  
Maize Domestication

The maize opaque2 (o2) mutant has a high nutritional value but it develops a chalky endosperm that limits its practical use. Genetic selection for o2 modifiers can convert the normally chalky endosperm of the mutant into a hard, vitreous phenotype, yielding what is known as quality protein maize (QPM). Previous studies have shown that enhanced expression of 27-kDa γ-zein in QPM is essential for endosperm modification. Taking advantage of genome-wide association study analysis of a natural population, linkage mapping analysis of a recombinant inbred line population, and map-based cloning, we identified a quantitative trait locus (qγ27) affecting expression of 27-kDa γ-zein. qγ27 was mapped to the same region as the major o2 modifier (o2 modifier1) on chromosome 7 near the 27-kDa γ-zein locus. qγ27 resulted from a 15.26-kb duplication at the 27-kDa γ-zein locus, which increases the level of gene expression. This duplication occurred before maize domestication; however, the gene structure of qγ27 appears to be unstable and the DNA rearrangement frequently occurs at this locus. Because enhanced expression of 27-kDa γ-zein is critical for endosperm modification in QPM, qγ27 is expected to be under artificial selection. This discovery provides a useful molecular marker that can be used to accelerate QPM breeding.

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