• Title/Summary/Keyword: Expected Inbreeding

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Genomic Heterogeneity of Chicken Populations in India

  • Rajkumar, Ullengala;Gupta, B. Ramesh;Reddy, A. Rajasekhara
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.12
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    • pp.1710-1720
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    • 2008
  • A comprehensive genome profiling study was undertaken based on automated genotyping and analysis of 20 microsatellite markers that involved 155 birds representing eight different populations. The distribution of microsatellite markers in each of these breeds helped us to decipher genetic heterogeneity, population genetic structure and evolutionary relationships of the present day chicken populations in India. All the microsatellite loci utilized for the analysis were polymorphic and reasonably informative. A total of 285 alleles were documented at 20 loci with a mean of 14.25 alleles/locus. A total of 103 alleles were found to be population/strain specific of which, only 30 per cent had a frequency of more than 10. The mean PIC values ranged from 0.39 for the locus ADL158 to 0.71 for loci MCW005 or ADL267 across the genomes and 0.55 in Dahlem Red to 0.71 in Desi (non-descript), among the populations. The overall mean expected and observed heterozygosity estimates for our populations were 0.68 and 0.64, respectively. The overall mean inbreeding coefficients (FIS) varied between -0.05 (Babcock) and 0.16 (Rhode Island Red). The pairwise FST estimates ranged from 0.06 between Aseel and Desi (non-descript) to 0.14 between Dahlem Red and Babcock. The Nei's genetic distance varied from 0.30 (WLH-IWD and WLH-IWF) to 0.80 (Dahlem Red and Babcock. Phylogenetic analysis grouped all the populations into two main clusters, representing i) the pure breeds, Dahlem Red and Rhode Island Red, and ii) the remaining six populations/strains. All the chicken populations studied were in the state of mild to moderate inbreeding except for commercial birds. A planned breeding is advised for purebreds to revive their genetic potential. High genetic diversity exists in Desi (non-descript), local birds, which can be exploited to genetically improve the birds suitable for backyard poultry.

Genetic characteristics of Korean Jeju Black cattle with high density single nucleotide polymorphisms

  • Alam, M. Zahangir;Lee, Yun-Mi;Son, Hyo-Jung;Hanna, Lauren H.;Riley, David G.;Mannen, Hideyuki;Sasazaki, Shinji;Park, Se Pill;Kim, Jong-Joo
    • Animal Bioscience
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    • v.34 no.5
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    • pp.789-800
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    • 2021
  • Objective: Conservation and genetic improvement of cattle breeds require information about genetic diversity and population structure of the cattle. In this study, we investigated the genetic diversity and population structure of the three cattle breeds in the Korean peninsula. Methods: Jeju Black, Hanwoo, Holstein cattle in Korea, together with six foreign breeds were examined. Genetic diversity within the cattle breeds was analyzed with minor allele frequency (MAF), observed and expected heterozygosity (HO and HE), inbreeding coefficient (FIS) and past effective population size. Molecular variance and population structure between the nine breeds were analyzed using a model-based clustering method. Genetic distances between breeds were evaluated with Nei's genetic distance and Weir and Cockerham's FST. Results: Our results revealed that Jeju Black cattle had lowest level of heterozygosity (HE = 0.21) among the studied taurine breeds, and an average MAF of 0.16. The level of inbreeding was -0.076 for Jeju Black, while -0.018 to -0.118 for the other breeds. Principle component analysis and neighbor-joining tree showed a clear separation of Jeju Black cattle from other local (Hanwoo and Japanese cattle) and taurine/indicine cattle breeds in evolutionary process, and a distinct pattern of admixture of Jeju Black cattle having no clustering with other studied populations. The FST value between Jeju Black cattle and Hanwoo was 0.106, which was lowest across the pair of breeds ranging from 0.161 to 0.274, indicating some degree of genetic closeness of Jeju Black cattle with Hanwoo. The past effective population size of Jeju Black cattle was very small, i.e. 38 in 13 generation ago, whereas 209 for Hanwoo. Conclusion: This study indicates genetic uniqueness of Jeju Black cattle. However, a small effective population size of Jeju Black cattle indicates the requirement for an implementation of a sustainable breeding policy to increase the population for genetic improvement and future conservation.

Genetic analysis of endangered species Crested Ibis (Nipponia nippon) microsatellite markers (Microsatellite Markers를 이용한 따오기의 유전적 특성 분석)

  • Kim, Da Hye;Kim, Yi Seul;Seo, Joo Hee;Kim, Sung Jin;Kong, Hong Sik
    • Korean Journal of Ornithology
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    • v.25 no.2
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    • pp.77-81
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    • 2018
  • The Korean Crested ibis Nipponia Nippon is an endangered species. A pair of Crested ibis was introduced from China in October 2008, and a successful program of artificial incubation of the species, and over 200 animals have been successfully bred through the restoration project up to 2017 at Upo ibis restoration center. We assessed genetic diversity and sex determination in the Korean Crested ibis. In total, 228 Crested ibis (115 females and 113 males) were identified. And genetic diversity measures, observed heterozygosity, expected heterozygosity, and polymorphic information content values were lower in 2017 than those in 2016. The inbreeding coefficient showed that the degree of ancestry increased in 2017. The decrease in polymorphism and increase in the degree of ancestry is thought to be due to inbreeding in such a small group. In this study provided important insight into protocols for genetic management of the breeding population of Korean Crested ibis in Korea and will help in extending the restoration program.

Genetic diversity of Saudi native chicken breeds segregating for naked neck and frizzle genes using microsatellite markers

  • Fathi, Moataz;El-Zarei, Mohamed;Al-Homidan, Ibrahim;Abou-Emera, Osama
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.12
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    • pp.1871-1880
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    • 2018
  • Objective: Recently, there has been an increasing interest in conservation of native genetic resources of chicken on a worldwide basis. Most of the native chicken breeds are threatened by extinction or crossing with ecotypes. Methods: Six Saudi native chicken breeds including black naked neck, brown frizzled, black, black barred, brown and gray were used in the current study. The aim of the current study was to evaluate genetic diversity, relationship and population structure of Saudi native chicken breeds based on 20 microsatellite markers. Results: A total of 172 alleles were detected in Saudi native chicken breeds across all 20 microsatellite loci. The mean number of alleles per breed ranged from 4.35 in gray breed to 5.45 in normally feathered black with an average of 8.6 alleles. All breeds were characterized by a high degree of genetic diversity, with the lowest heterozygosity found in the brown breed (72%) and the greatest in the frizzled and black barred populations (78%). Higher estimate of expected heterozygosity (0.68) was found in both black breeds (normal and naked neck) compared to the other chicken populations. All studied breeds showed no inbreeding within breed (negative inbreeding coefficient [$F_{IS}$]). The phylogenetic relationships of chickens were examined using neighbor-joining trees constructed at the level of breeds and individual samples. The neighbor-joining tree constructed at breed level revealed three main clusters, with naked neck and gray breeds in one cluster, and brown and frizzled in the second cluster leaving black barred in a separate one. Conclusion: It could be concluded that the genetic information derived from the current study can be used as a guide for genetic improvement and conservation in further breeding programs. Our findings indicate that the Saudi native chicken populations have a rich genetic diversity and show a high polymorphism.

Time Trends in Estimates of Genetic Parameters in a Population of Layer Breeders (난용종계 집단에서의 선발에 의한 유전모수 변화 양상)

  • 최연호;오봉국
    • Korean Journal of Poultry Science
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    • v.17 no.4
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    • pp.255-268
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    • 1990
  • This study was carried out to investigate the time-trends of genetic parameters of the dosed flock population which selected for improving egg production. Data for two layer pure lines, Line-W (Single Comb White Leghorn) and Line-B (brown layer) which have been maintained at the Mani Breeding Farm were collected from 1980 to 1985 during 5 generations. The effective number of parents per generation ranged from 148 to 366 in Line-W and 85 to 355 in Line-B, and the cumulative expected inbreeding coefficients during 5 generations of selection were 15% and 1.6%. So inbreeding could not be considered a critical factor on estimating the genetic parameters, heritabilities and genetic correlations Heritabilities of EN 300 and EN 400, primary two selected traits were significantly decreased during 5 generations but the estimates of the other 03its not showed the consistent decreasing pattern significantly. No time trends of probable consequence were evident in the genetic correlation coefficients of the traits studied. The reason for that situation was attributed to the fact that selection was conducted for multiple objectives and the relative importance of selection for the studied traits were not consistent by generations.

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Genetic Variation in the Endemic Rare Tree Species, Juniperus chinensis var. sargentii HENRY (희귀(稀貴) 수종(樹種) 눈향나무 집단(集團)의 동위효소(同位酵素) 분석(分析)에 의한 유전변이(遺傳變異) 연구(硏究))

  • Yang Byeung-Hoon;Kwon Hae-Yun;Han Sang-Don
    • Korean Journal of Plant Resources
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    • v.19 no.1
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    • pp.76-82
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    • 2006
  • Genetic variation of two Juniperus chinensis var. sargentii populations in Mt. Seorak and Mt. Halla was investigated by isozyme analysis at reproducible 11 loci of 7 isozyme systems(Aat-1, Aat-2, Gdh, Idh, Lap, Mdh-1, Mdh-2, Mdh-3, 6Pgd, Pgi-1, and Pgi-2), of which 7 loci were polymorphic. The levels of genetic diversity of two populations were A=2.2, $A_e=1.61,\;P_{95}=54.5,\;H_{o}=0.179,\;H_e=0.287$(Mt. Seorak population) and A=2.1, $A_e=1.48,\;P_{95}=63.6,\;H_{o}=0.270,\;H_e=0.250$(Mt. Halla population), respectively. These values were similar to and/or somewhat higher than those observed in other Korean native conifers. Moderately low degree of genetic differentiation was observed between 2 analyzed populations ($F_{ST}=0.039$). Heterozygosity of the population in Mt. Seorak was significantly lower than expected, and much high level of inbreeding coefficient(F=0.376) was observed. Considering the limited population size and distribution range of the population, the population seemed to be influenced by inbreeding and/or random genetic drift, Consequently, Mt. Seorak population should be considered to be a more important candidate for the conservation of J. chinensis var. sargentii.

Multilocus Genotyping to Study Population Structure in Three Buffalo Populations of India

  • Tantia, M.S.;Vijh, R.K.;Mishra, Bina;Kumar, S.T. Bharani;Arora, Reena
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.8
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    • pp.1071-1078
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    • 2006
  • Three buffalo populations viz. Bhadawari, Tarai and local buffaloes of Kerala were genotyped using 24 heterologous polymorphic microsatellite loci. A total of 140 alleles were observed with an average observed heterozygosity of 0.63. All the loci were neutral and 18 out of the 24 loci were in Hardy Weinberg Equilibrium. The $F_{IS}$ values (estimate of inbreeding) for 16 loci in all the three populations were negative. This indicated lack of population structure in the three populations. The effective number of immigrants was 5.88 per generation between the Tarai and Bhadawari populations which was quite high suggesting substantial gene flow. The genetic distances revealed closeness between the Tarai and Bhadawari populations which was expected from geographical contiguity. The FST values were not significantly different from zero showing no population differentiation. The Correspondence Analysis based on the allelic frequency data clustered the majority of the Tarai and Bhadawari individuals as an admixture.

Genetic Structure In Korean Populations of Atractomorpha lata (Orthoptera: Pyrgomorphidae)

  • Jeong, Myeong-Ji;Gang, Sun-Seok;Yeehn, Yeeh
    • Animal cells and systems
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    • v.1 no.4
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    • pp.535-538
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    • 1997
  • Allozyme variation of seven enzyme systems was analyzed from 202 individuals from four Korean populations of Atractomorpha lata. These populations exhibit higher levels of values of in most other insects with a mean 64% of polymorphic loci and a mean 0.384 of expected heterozygosity within populations. Fixation indices indicated considerable substructuring within populations sampled (mean $F_{is}=0.403)$, indicating probable inbreeding or assortative mating coupled with restricted migration between subpopulations. This was supported by the field observation that the species exists as small, discrete colonies in meadow habitats and females carry males. In addition, significant differences in allere frequencies between males and females at polymorphic loci examined (70%, 16 of 23 cases) could account for the observed heterozygote deficiencies.

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Genetic Diversity and Genetic Structure of Acer pseudosieboldianum Populations in South Korea Based on AFLP Markers (AFLP 마커를 이용한 당단풍나무 집단의 유전다양성과 유전구조)

  • Ahn, Jiyoung;Hong, Kyung-Nak;Baek, Seung-Hoon;Lee, Min-Woo;Lim, Hyo-In;Lee, Jei-Wan
    • Journal of Korean Society of Forest Science
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    • v.105 no.4
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    • pp.414-421
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    • 2016
  • Fourteen Acer pseudosieboldianum populations in South Korea were used to estimate genetic diversity, genetic differentiation and genetic relationships using seven AFLP primer combinations. The average of effective alleles ($A_e$), the proportion of polymorphic loci (%P) and Shannon's diversity index (I) was 1.4, 82.2% and 0.358, respectively. The expected heterozygosity ($H_e$) under Hardy-Weinberg equilibrium was 0.231 and the expected heterozygosity (Hj) from Bayesian inference was 0.253. The level of genetic diversity was moderate compared to those of Genus Acer and lower than those of other species having similar ecological niche and life history. The inbreeding coefficient within populations ($F_{IS}$) from Bayesian method was 0.712 and it could be influenced by selfing or biparental inbreeding to induce homozygote excess. The level of genetic differentiation was 0.107 from AMOVA (${\Phi}_{ST}$) and 0.110 from Bayesian method (${\Phi}^{II}$). The genetic differentiation was lower than those of other species having similar ecological niche and life history. Ulleungdo population had the lowest level of genetic diversity and was genetically the most distinct population from others in the study. We consider that founder effect and genetic drift might be occurred to reduce genetic diversity and then the geographical isolation might interrupt gene flow to aggravate it.

Population Structure and Genetic Bottleneck Analysis of Ankleshwar Poultry Breed by Microsatellite Markers

  • Pandey, A.K.;Kumar, Dinesh;Sharma, Rekha;Sharma, Uma;Vijh, R.K.;Ahlawat, S.P.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.7
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    • pp.915-921
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    • 2005
  • Genetic variation at 25 microsatellite loci, population structure, and genetic bottleneck hypothesis were examined for Ankleshwar poultry population found in Gujrat, India. The estimates of genetic variability such as effective number of alleles and gene diversities revealed substantial genetic variation frequently displayed by microsatellite markers. The average polymorphism across the studied loci and the expected gene diversity in the population were 6.44 and 0.670${\pm}$0.144, respectively. The population was observed to be significantly differentiated into different groups, and showed fairly high level of inbreeding (f = 0.240${\pm}$0.052) and global heterozygote deficit. The bottleneck analysis indicated the absence of genetic bottleneck in the past. The study revealed that the Ankleshwar poultry breed needs appropriate genetic management for its conservation and improvement. The information generated in this study may further be utilized for studying differentiation and relationships among different Indian poultry breeds.