Pool J E, Wong A, Aquadro C F
Department of Molecular Biology and Genetics, Cornell University, 233 Biotechnology Building, Ithaca, NY 14853, USA.
Heredity (Edinb). 2006 Jul;97(1):27-32. doi: 10.1038/sj.hdy.6800830. Epub 2006 May 10.
We report the identification of male-killing Spiroplasma in a wild-caught female Drosophila melanogaster from Uganda, the first such infection to be found in this species outside of South America. Among 38 female flies collected from Namulonge, Uganda in April, 2005, one produced a total of 41 female offspring but no males. PCR testing of subsequent generations revealed that females retaining Spiroplasma infection continued to produce a large excess of female progeny, while females that had lost Spiroplasma produced offspring with normal sex ratios. Consistent with earlier work, we find that male-killing and transmission efficiency appear to increase with female age, and we note that males born in sex ratio broods display much lower survivorship than their female siblings. DNA sequence comparisons at three loci suggest that this Spiroplasma strain is closely related to the male-killing strain previously found to infect D. melanogaster in Brazil, although part of one locus appears to show a recombinant history. Implications for the origin and history of male-killing Spiroplasma in D. melanogaster are discussed.
我们报告了在一只从乌干达野生捕获的雌性黑腹果蝇中鉴定出杀雄螺原体，这是在南美洲以外的该物种中首次发现此类感染。在2005年4月从乌干达纳穆隆格采集的38只雌性果蝇中，有一只总共产生了41只雌性后代但没有雄性。对后代的PCR检测显示，保留螺原体感染的雌性继续产生大量雌性后代，而失去螺原体的雌性产生的后代性别比例正常。与早期研究一致，我们发现杀雄和传播效率似乎随雌性年龄增加而提高，并且我们注意到在性别比例异常的群体中出生的雄性比其雌性同胞的存活率低得多。三个基因座的DNA序列比较表明，这种螺原体菌株与先前在巴西发现感染黑腹果蝇的杀雄菌株密切相关，尽管其中一个基因座的一部分似乎显示出重组历史。本文讨论了黑腹果蝇中杀雄螺原体的起源和历史。
