Mitochondrial DNA variation and genetic structure in populations of Drosophila melanogaster

The understanding of the genetic structure of a species can be improved by considering together data from different types of genetic markers. In the past, a number of worldwide populations of Drosophila melanogaster have been extensively studied for several such markers, including allozymes, chromosomal inversions, and quantitative characters. Here we present results from a study of restriction- fragment-length polymorphisms of mitochondrial DNA (mtDNA) in 92 isofemale lines from many of the same geographic populations of D. melanogaster. Eleven restriction enzymes were used, of which four revealed restriction-site polymorphism. A total of 24 different haplotypes were observed, of which 18 were unique to single populations. In many populations, the unique haplotypes have reached high frequency without being observed in neighboring populations. A Wagner parsimony tree reveals that mutationally close variants show geographical clumping, suggesting local differentiation of mtDNA in populations. The Old-World and the New-World populations are differentiated, with the predominant Old-World haplotype being virtually absent from the New World. These results contrast with those for the nuclear genes, in which many loci show parallel clines in different continents, and suggest a common origin of D. melanogaster populations in North America.      

中国高山ping亚属（Subgerus Alticola）的系统类与分布

高山ｐｉｎｇ亚属广布于中亚山地，即从喜马拉雅山、兴都库库会经帕米尔、天山、西茂而至图瓦、抗爱山和贝加尔湖一带。中国过去仅记录２种：银色高山ｐｉｎｇ（Ａｌｔｉｃｏｌａ ａｒｇｅｎｔａｔｃｓ Ｓｅｖｅｒｔｓｏｖ；有时定作劳氏高山ｐｉｎｇＡ．ｒｏｙｌｅｉ的一亚种）和斯氏高山ｐｉｎｇ。本文依据形态学资料和采用判别函数分析的方法，对该亚属进行了研究。我们认为中国高山ｐｉｎｇ至少有３个以上的物种存在，现概述于     

Electrical burns causing a urinary bladder fistula. Case report.

We present a patient with electrical burns which resulted in loss of the right upper arm and a urinary bladder fistula. A jump flap was used to cover the repaired bladder, and also to cover the stump of the amputated right arm.     

Biological characteristics of the peptides α and β isolated from bovine seminal plasma

The bull seminal plasma peptides α andβ have been examined for their biological properties. While both the peptides were able to inhibit the human chorionic gonadotropin-dependent uterine response in the mouse, α alone exhibits the property of suppressing post-castrational rise in gonadotropin in appropriate animal models. This suggests that the peptideβ must be acting directly on the ovary to suppress estrogen production and, consequently, the uterine weight increase. Such a possibility was confirmed when α andβ were examined by the coupled bioassay which is capable of discriminating between pituitary feedback factors and those acting directly on the gonad. In a test system designed to examine chronic effects, both α andβ showed evidence of acting directly on the ovary to inhibit human menopausal gonadotropin-induced estrogen production. Such a direct action could not be correlated with the relative potencies of these peptides when examined for their follicle stimulating hormone-receptor binding inhibitor and lutinizing hormone-receptor binding inhibitor activities.