Showing papers by "Ranjan Deka published in 1990"
TL;DR: The present data and a similar study in Laotians suggest that the Lao-speaking populations of the Mekong River basin in northeastern Thailand and Laos have the highest frequencies of the Hb CS gene in Southeast Asia.
Abstract: The distribution of the hemoglobin Constant Spring (Hb CS) gene in eight populations in Southeast Asia (including Assam) was determined using oligonucleotide hybridization. Hb CS was absent in two Assamese populations with a high prevalence of Hb E. The Hb CS gene frequency was 0.033 in northern Thailand and near 0.01 in central Thailand and Cambodia. High frequencies, between 0.05 and 0.06, were observed in northeastern Thailand. The present data and a similar study in Laotians suggest that the Lao-speaking populations of the Mekong River basin in northeastern Thailand and Laos have the highest frequencies of the Hb CS gene in Southeast Asia.
54 citations
Journal Article•
TL;DR: The results suggest that ovarian teratomas can provide a rapid method for mapping genes relative to the centromere, and Estimated gene-centromere distances suggest that, while recombination occurs normally in ovarian ter atomas arising by meiosis II errors, ovarian Teratomas arisingBy meiosis I nondisjunction have altered patterns of recombination.
Abstract: Chromosomal heteromorphisms and DNA polymorphisms have been utilized to identify the mechanisms that lead to formation of human ovarian teratomas and to construct a gene-centromere map of chromosome 1 by using those teratomas that arise by meiotic nondisjunction Of 61 genetically informative ovarian teratomas, 213% arose by nondisjunction at meiosis I, and 393% arose by meiosis II nondisjunction Eight polymorphic marker loci on chromosome 1p and one marker on 1q were used to estimate a gene-centromere map The results show clear linkage of the most proximal 1p marker (NRAS) and the most proximal 1q marker (D1S61) to the centromere at a distance of 14 cM and 20 cM, respectively Estimated gene-centromere distances suggest that, while recombination occurs normally in ovarian teratomas arising by meiosis II errors, ovarian teratomas arising by meiosis I nondisjunction have altered patterns of recombination Furthermore, the estimated map demonstrates clear evidence of chiasma interference Our results suggest that ovarian teratomas can provide a rapid method for mapping genes relative to the centromere
53 citations