A comprehensive review of HVS-I mitochondrial DNA variation of 19 Iranian populations.

Iran is located along the Central Asian corridor, a natural artery that has served as a cross-continental route since the first anatomically modern human populations migrated out of Africa. We compiled and reanalyzed the HVS-I (hypervariable segment-I) of 3840 mitochondrial DNA (mtDNA) sequences from 19 Iranian populations and from 26 groups from adjacent countries to give a comprehensive review of the maternal genetic variation and investigate the impact of historical events and cultural factors on the maternal genetic structure of modern Iranians. We conclude that Iranians have a high level of genetic diversity. Thirty-six haplogroups were observed in Iran's populations, and most of them belong to widespread West-Eurasian haplogroups, such as H, HV, J, N, T, and U. In contrast, the predominant haplogroups observed in most of the adjacent countries studied here are H, M, D, R, U, and C haplogroups. Using principal component analysis, clustering, and genetic distance-based calculations, we estimated moderate genetic relationships between Iranian and other Eurasian groups. Further, analyses of molecular variance and comparing geographic and genetic structures indicate that mtDNA HVS-I sequence diversity does not exhibit any sharp geographic structure in the country. Barring a few from some culturally distinct and naturally separated minorities, most Iranian populations have a homogenous maternal genetic structure.

Following the Trace of HVS II Mitochondrial Region Within the Nine Iranian Ethnic Groups Based on Genetic Population Analysis.

The Iranian gene pool is seen as an important human genetic resource for investigating the region connecting Mesopotamia and the Iranian plateau. The main objective of this study was to explore gene flow in nine Iranian ethnic/subpopulation groups (402 samples) by examining mtDNA HVS2 sequence variations. This then allowed us to detect mtDNA HVS2 sequence mutations in two independent thalassemia and cystic fibrosis patient sample groups. The patient groups did not explicitly belong to any of the aforementioned nine subpopulations. Across all subpopulations, the haplogroups B4a1c3a, H2a2a1, N10b, H2a2a2, and J1 were seen to be predominant. High haplogroup diversities along with admixture of the exotic groups were observed in this study. The Arab subpopulation was shown to be independent from the others. It was revealed that there is a far distant relationship between Arab and Azeri groups. The thalassemia patient group, represented an almost random sample of most Iranian ethnic groups, and revealed few significant differences (P < 0.05) in their HVS2 sequence. It turned out that the IVS II-I (G → A) mutation in the thalassemia ß-globin gene was highly significant. Since the thalassemia patients in the present study represent many unique haplotypes, we can begin to comprehend the importance of mtDNA with this disease and the necessity for more studies in this context.

Microsatellite Analysis of Genetic Diversity and Population Structure of the Iranian Kurdish Horse.

Native breeds are essential for national stocks and genetic reservoir; therefore, the preservation of indigenous breeds is a key policy priority for countries around the world. Many conservationists would assert that genetic diversity is a prerequisite for adaptive evolution, and preserving genetic diversity will need conservation efforts for the long-term survival of domestic species. This study intended to evaluate the genetic diversity of the Iranian Kurdish horse population based on microsatellite indicators, which can partially prevent it from becoming extinct. Fifty-eight tail hair and blood samples were randomly collected from Kurdistan, Kermanshah, Ilam, West Azerbaijan, Isfahan, Kerman, Hamadan, and Tehran. Genomic DNA extraction was performed by a modified salting out method. The polymerase chain reaction amplification conditions were also separately undertaken for each marker. All microsatellite loci revealed polymorphisms in the studied population. Genetic variation was examined using 12 microsatellite loci (HMS7, HMS3, HMS2, HMS6, ASB2, ASB23, VHL20, HTG10, LEX33, ASB17, AHT4, and AHT5). We found that the means of the observed and effective number of alleles were 7.58 and 4.95, with the minimum and maximum values for each of these indices associated with the loci of HMS2 and ASB17, respectively. Moreover, the mean of observed and expected heterozygosity, polymorphism information content, and Shannon's Information Index of the Iranian Kurdish population were 0.77, 0.78, 0.75, and 1.67, respectively, indicating a high degree of genetic diversity in the entire studied population. More specifically, we acquired a range of new alleles in the Iranian Kurdish horse breed that differed in their genetic structure to those of other Iranian breeds in other studies. This study provides an exciting opportunity to improve our knowledge of genetic information which will be beneficial as a base to identify purebred Kurdish horses for a further Iranian Kurdish horse genetic and breeding program.

Genome-wide association studies reveal novel loci associated with carcass and body measures in beef cattle.

Genomic selection has an essential role in the livestock economy by increasing selection productivity. Genomics provides a mechanism to increase the rate of genetic gain using marker-assisted selection. Various quantitative trait loci (QTL) associated with body, carcass and meat quality traits in beef cattle have been found. It is widely accepted that QTL traits in livestock species are regulated by several genes and factors from the environment. Genome-wide association studies (GWAS) are a powerful approach in identifying QTL and to establish genomic regions harboring the genes and polymorphisms associated with specific characteristics in beef cattle. Due to their impact on economic returns, growth, carcass and meat quality traits of cattle are frequently used as essential criteria in selection in breeding programs., GWAS has been used in beef cattle breeding and genetic program and some progress has been made. Furthermore, numerous genes and markers related to productivity traits in beef cattle have been found. This review summarizes the advances in the use of GWAS in beef cattle production and outlines the associations with growth, carcass, and meat quality.

The genetic polymorphisms of melanocortin-4 receptor gene are associated with carcass quality traits in a Chinese indigenous beef cattle breed.

Melanocortin-4 receptor (MC4R) was considered as an essential modifiers in feelings intake, the regulation of metabolism and body weight. This study aimed at identifying polymorphisms in MC4R gene that might associate with carcass quality traits in Chinese indigenous beef cattle breed. qPCR analysis showed that the MC4R gene was widely expressed in various tissues, with predominantly expression levels in heart. Three single-nucleotide polymorphisms (SNPs) were identified, including a mutation (g.85A > G) in 5'untranslated regions (UTR) and two mutations (g.927C > T and g.1069C > G) in exon 1. Based on the χ2 test, both g.927C > T and g.1069C > G loci fitted with Hardy-Weinberg equilibrium (P > .05). Population genetic analysis showed that except for g.85A > G, the other detected SNPs strongly affected the bovine back fat thickness and intramuscular fat content (P < .05). The individuals with Hap1/4 diplotypes (ACC-ATG) were highly significantly associated with carcass quality traits than the other diplotypes (P < .01 or P < .05). Results indicated that the bovine MC4R gene polymorphisms were implicated as genetic markers of potential importance in marker-assisted selection (MAS) strategies to improve carcass quality in Chinese Qinchuan cattle.