Further Characterization of Genetic Elements Associated with the Segregation Distorter Phenomenon in DROSOPHILA MELANOGASTER.
Further Characterization of Genetic Elements Associated with the Segregation Distorter Phenomenon in DROSOPHILA MELANOGASTER.
复制标题
与果蝇分离扭曲现象相关的遗传元件的进一步表征。
作者：
C. B. Sharp;A. Hilliker;D. Holm
分离扭曲 (SD) 与果蝇第二条染色体相关，已知会导致带有非 SD 同源物的精子导致杂合雄性功能障碍。在早期的研究中，使用不同的、独立衍生的 SD 染色体，三个主要基因座被确定为导致雄性分离比扭曲的原因。在这项研究中，SD-5 染色体的遗传成分已成为进一步研究的主题，我们的研究结果提供了以下信息。交叉分析证实了 Sd 基因座映射到远离遗传标记 pr 但与之密切相关的位置。自发和辐射诱导的重组分析和缺陷研究为以下观点提供了坚实的支持：Rsp（响应者）基因座位于 2 号染色体的近端异染色质内，遗传标记 lt 和 rl 之间，最有可能位于右臂的异染色质中。然而，这项研究的主要重点是提供 SD 增强子 [E(SD)] 遗传特性的更好定义。我们的研究结果将该基因座置于 2 号染色体左臂异染色质中两个最近端必需基因的区域内。此外，我们的分析揭示了 E(SD) 基因座可能与独立于 Sd 引起的减数分裂驱动有关。
Segregation Distorter, SD, associated with the second chromosome of Drosophila melanogaster, is known to cause sperm bearing the non-SD homologue to dysfunction in heterozygous males. In earlier studies, using different, independently derived, SD chromosomes, three major loci were identified as contributing to the distortion of segregation ratios in males. In this study the genetic components of the SD-5 chromosome have been the subjects of further investigation, and our findings offer the following information. Crossover analysis confirms the mapping of the Sd locus to a position distal to but closely linked with the genetic marker pr. Spontaneous and radiation-induced recombinational analyses and deficiency studies provide firm support to the notion that the Rsp (Responder) locus lies within the proximal heterochromatin of chromosome 2, between the genetic markers lt and rl and most likely in the heterochromatin of the right arm. The major focus of this study, however, has been on providing a better definition of the genetic properties of the Enhancer of SD [E(SD)]. Our findings place this locus within the region of the two most proximal essential genes in the heterochromatin of the left arm of chromosome 2. Moreover, our analysis reveals a probable association of the E(SD) locus with a meiotic drive independent of that caused by Sd.