Goñi Beatriz, Matsuda Muneo, Tobari Yoshiko N
Department of Biology, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan.
Genome. 2006 Nov;49(11):1374-83. doi: 10.1139/g06-106.
A cytogenetic analysis of male crossing over in Drosophila ananassae revealed that cytological exchanges resulted in genetic crossing over, and that chiasma frequency and the genetic recombination correlated positively in chromosomes 2 and 3. Furthermore, the frequency of chromosome breakages correlated positively with chiasma frequency. Paracentric inversion heterozygosity had no detectable influence on the chromosome pairing or exchange events within the inversion loop at meiosis. Scoring of the chiasma demonstrated that males homozygous for the previously mapped enhancers of male crossing over had low frequencies of chiasmata, whereas higher frequencies of chiasmata were observed in males heterozygous for enhancers. The results presented here indicate that the genetic factors controlling male crossing over are involved in the origin of chromosome breakages and in exchange events.
对拟果蝇雄性交换的细胞遗传学分析表明，细胞学交换导致了基因交换，并且在2号和3号染色体上，交叉频率与基因重组呈正相关。此外，染色体断裂频率与交叉频率呈正相关。臂内倒位杂合性对减数分裂时倒位环内的染色体配对或交换事件没有可检测到的影响。交叉的计分显示，对于先前定位的雄性交换增强子纯合的雄性交叉频率较低，而在增强子杂合的雄性中观察到较高的交叉频率。此处给出的结果表明，控制雄性交换的遗传因素参与了染色体断裂的起源和交换事件。
