Chromosomal DNA Variation Research Articles

Allele and haplotype diversity of 17 Y-STRs loci in the northern region Pashtun (Pathans) population of Pakistan

A total of 17 Y-linked short tandems repeat (Y-STRs) loci (DYS19, DYS385a, DYS385b, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, and GATA H4) were genotyped in the Pashtun (Pathans) male population residing in the northern region of Pakistan. The Pashtun population, in spite of its decisive geographic location for repopulation movements between Pakistan, Afghanistan and India over time, has been insufficiently characterised at the genetic level, especially for Y chromosomal DNA variation. To understand the genetic structure characterisation of the Pashtun resident population of the northern region, we have utilised the Y chromosome STRs diversity, haplotype diversity and discrimination capacity. In this work, a total of 67 distinct haplotypes were observed in the resident population of Pashtun living in the northern region of the country, and they showed a high haplotype diversity (0.9756) and discrimination capacity (89.3%); five individuals shared a single haplotype. Genetic distances between the studied population and 11 other populations were calculated based on haplogroup frequencies with Analysis of Molecular Variance (AMOVA).

A Y chromosomal influence on prostate cancer risk: the multi-ethnic cohort study

Background: A Y chromosomal role in prostate cancer has previously been suggested by both cytogenetic findings and patterns of Y chromosomal gene expression. We took advantage of the well established...

Genetic relationship between Korean and Mongolian populations based on the Y chromosome DNA variation

We analyzed seven Y chromosome binary markers (YAP, RPS4Y711, M9, M175, LINE1, SRY+465 and 47z) in samples from a total of 254 males from Koreans and two Mongolian ethnic groups (Buryat and Khalkh) to study the genetic relationship among these populations. We found eight distinct Y haplogroups constructed from the seven binary markers. Haplogroup DE‐YAP was present at extremely low frequencies (∼2%) in the Korean and Mongolian populations. This result is consistent with earlier reports that showed the YAP+ chromosomes to be highly polymorphic only in populations from Japan and Tibet in east Asia. The observed high frequency of haplogroup C‐RPS4Y711 in the Mongolian populations (∼40%) is concordant with recent findings, showing that the RPS4Y711‐T chromosomes were distributed at high frequencies in Siberian and Mongolian populations compared with most other populations from east Asia. Thus, the relatively moderate frequency of haplogroup C‐RPS4Y711 in Koreans (∼15%) can be seen as genetic evidence for prob...

Y chromosomal DNA variation in east Asian populations and its potential for inferring the peopling of Korea.

We have examined variations of five polymorphic loci (DYS287, DXYS5Y, SRY465, DYS19, and DXYS156Y) on the Y chromosome in samples from a total of 1260 males in eight ethnic groups of East Asia. We found four unique haplotypes constructed from three biallelic markers in these samples of East Asians. The Japanese population was characterized by a relatively high frequency of either the haplotype I-2b (-/Y2/T) or II-1 (+/Y1/C). These dual patterns of the distribution of Y chromosomes (I-2b/II-1) were also found in Korea, although they were present at relatively low frequencies. The haplotype II-1 was present in Northeast Asian populations (Chinese, Japanese, Koreans, and Mongolians) only, except for one male from the Thai population among the Southeast Asian populations (Indonesians, Philippines, Thais, and Vietnamese). The Japanese were revealed to have the highest frequency of this haplotype (27.5%), followed by Koreans (2.9%), Mongolians (2.6%), and mainland Chinese (2.2%). In contrast, the frequency of the haplotype I-2b was found to be 17.1% in the Japanese, 9.5% in Indonesian, 6.3% in Korean, 3.8% in Vietnamese, and 2.7% in Thai samples. These findings suggested that the chromosomes of haplotype I-2b were likely derived from certain areas of Northeast Asia, the region closest to Southeast Asia. Phylogenetic analysis using the neighbor-joining tree also reflected a general distinction between Southeast and Northeast Asian populations. The phylogeny revealed a closer genetic relationship between Japanese and Koreans than to the other surveyed Asian populations. Based on the result of the dual patterns of the haplotype distribution, it is more likely that the population structure of Koreans may not have evolved from a single ancient population derived from Northeast Asians, but through dual infusions of Y chromosomes entering Korea from two different waves of East Asians.

Karyotype, Nuclear and Chromosomal DNA Variation in Lens culinaris Med.

Detailed somatic karyotype analysis and nuclear DNA estimations in 10 varieties of lentil (Lens culinaris Med.) revealed significant intervarietal variation for chromatin and nuclear DNA contents. The lentil karyotypes were symmetric with preponderance of metacentric chromosomes. Secondary constrictions, located very near to centromere, were observed in one pair of chromosomes each in only 2 varieties, while in the remaining varieties they were not detectable. Correlation analysis revealed a positive linear relationship of 2C DNA amount with total chromosome volume and nuclear area while DNA density has negative relationship with nuclear area. The results indicate that quantitative DNA changes associated with evolution of varieties have affected all chromosomes within the complements but not to the same magnitude.

Chromosomal DNA variation, genomic constraints and recombination in Lathyrus

There is approximately a doubling of the total nuclear DNA between the 8 Lathyrus species and there are significant differences in the amounts of DNA in euchromatin and heterochromatin. Between the 8 species chiasma frequency and total nuclear DNA are not correlated but within complements it is positively correlated with the amount of DNA in the chromosomes. There is no significant correlation between chiasma frequency and euchromatin DNA nor between chiasma frequency and heterochromatin DNA among species, but among chromosomes, as with total DNA, it is positively correlated with euchromatin DNA and heterochromatin DNA. Results show that despite the large differences in DNA amounts between species there are genomic constraints underlying the frequency and distribution of chiasmata in the chromosome complements.