Polymorphisms in the C-type lectin genes cluster in chromosome 19 and predisposition to severe acute respiratory syndrome coronavirus (SARS-CoV) infection

Background: Polymorphisms of CLEC4M have been associated with predisposition for infection by the severe acute respiratory syndrome coronavirus (SARS-CoV). DC-SIGNR, a C-type lectin encoded by CLEC4M, is a receptor for the virus. A variable number tandem

Localization of a novel gene for congenital nonsyndromic simple microphthalmia to chromosome 2q11-14

Microphthalmia is a clinically and genetically heterogeneous disorder of eye development. The genetic basis of nonsyndromic microphthalmia is not yet fully understood. Previous studies indicated that disease pedigrees from different genetic backgrounds co

Mitochondrial genome evidence reveals successful Late Paleolithic settlement on the Tibetan Plateau

Due to its numerous environmental extremes, the Tibetan Plateau -the world's highest plateau-is one of the most challenging areas of modern human settlement. Archaeological evidence dates the earliest settlement on the plateau to the Late Paleolithic, whi

Tracing the Origins of Hakka and Chaoshanese by Mitochondrial DNA Analysis

Hakka and Chaoshanese are two unique Han populations residing in southern China but with northern Han (NH) cultural traditions and linguistic influences. Although most of historical records indicate that both populations migrated from northern China in the last two thousand years, no consensus on their origins has been reached so far. To shed more light on the origins of Hakka and Chaoshanese, mitochondrial DNAs (mtDNAs) of 170 Hakka from Meizhou and 102 Chaoshanese from Chaoshan area, Guangdong Province, were analyzed. Our results show that some southern Chinese predominant haplogroups, e.g. B, F, and M7, have relatively high frequencies in both populations. Although median network analyses show that Hakka/Chaoshanese share some haplotypes with NH, interpopulation comparison reveals that both populations show closer affinity with southern Han (SH) populations than with NH. In consideration of previous results from nuclear gene (including Y chromosome) research, it is likely that matrilineal landscapes of both Hakka and Chaoshanese have largely been shaped by the local people during their migration southward and/or later colonization in southern China, and factors such as cultural assimilation, patrilocality, and even sex-bias in the immigrants might have played important roles during the process. Am J Phys Anthropol 141:124-130, 2010. (C) 2009 Wiley-Liss, Inc.

Distinctive Paleo-Indian Migration Routes from Beringia Marked by Two Rare mtDNA Haplogroups

Background: It is widely accepted that the ancestors of Native Americans arrived in the New World via Beringia approximately 10 to 30 thousand years ago (kya). However, the arrival time(s), number of expansion events, and migration routes into the Western

Nucleotide variation and recombination along the fourth chromosome in Drosophila simulans

The fourth chromosome of Drosophila melanogaster and its sister species are believed to be nonrecombining and have been a model system for testing predictions of the effects of selection on linked, neutral variation. We recently examined nucleotide variat

Recombination Yet Inefficient Selection along the Drosophila melanogaster Subgroup's Fourth Chromosome

A central goal of evolutionary genetics is an understanding of the forces responsible for the observed variation, both within and between species. Theoretical and empirical work have demonstrated that genetic recombination contributes to this variation by breaking down linkage between nucleotide sites, thus allowing them to behave independently and for selective forces to act efficiently on them. The Drosophila fourth chromosome, which is believed to experience no-or very low-rates of recombination has been an important model for investigating these effects. Despite previous efforts, central questions regarding the extent of recombination and the predominant modes of selection acting on it remain open. In order to more comprehensively test hypotheses regarding recombination and its potential influence on selection along the fourth chromosome, we have resequenced regions from most of its genes from Drosophila melanogaster, D. simulans, and D. yakuba. These data, along with available outgroup sequence, demonstrate that recombination is low but significantly greater than zero for the three species. Despite there being recombination, there is strong evidence that its frequency is low enough to have rendered selection relatively inefficient. The signatures of relaxed constraint can be detected at both the level of polymorphism and divergence.

Localization of Sry gene on Y chromosome of Muntjac munticus vaginalis

The chromosomes 1, Y-1, Y-2 of Muntjac munticus vaginalis were isolated by fluorescence activated chromosome sorting and amplified by degenerate oligonucleotide primed-polymerase chain reaction ( DOP-PCR). A primer pair within human Sry HMG box was design

Numbers of migratory waterbirds at Lake Lashihai, China

Between October 1999 and April 2000, WC surveyed the waterbirds at Lake Lashihai, China. A total of 52 species were recorded, of which one species was a resident, 34 were winter visitors, and 17 were passage migrants. Species richness was highest in November. Passage migrants mainly occurred in October, November, and April, and they stayed longer at the lake during their autumn migration than during the spring migration. The seasonal distribution pattern of total numbers of all waterbirds was bimodal. One peak occurred between late December and early January, and the other in middle March. The seasonal distribution patterns of 15 common species have been classified a. bimodal, unimodal, or irregular. The numbers of five common species were variable in middle winter, and their numerical Change in contiguous weeks were more than 30%, suggesting that local movements might be frequent.

Migration routes and stopover sites of Black-necked Cranes determined by satellite tracking

Because their breeding and wintering areas are in remote locations, little is known about the biology of Black-necked Cranes (Grus nigricollis), including their migratory behavior. Using satellite telemetry, we monitored the migration of Black-necked Cran

Sorex bedfordiae has the Smallest Diploid Chromosome Number of the XY Group in the Genus Sorex (Mammalia, Soricidae)

Karyological data on the lesser stripe-backed shrew, Sorex bedfordiae, were obtained from four specimens collected on Mt. Laojun, Lijiang District, Yunnan Province, China. Three of the four S. bedfordiae specimens had karyotypes consisting of 2n=26, NFa=4