Additive Effects of Multiple SEGREGATION DISTORTER ( SD) Chromosomes on Sperm Dysfunction in DROSOPHILA MELANOGASTER.
Additive Effects of Multiple SEGREGATION DISTORTER ( SD) Chromosomes on Sperm Dysfunction in DROSOPHILA MELANOGASTER.
复制标题
多重分离扭曲 (SD) 染色体对果蝇精子功能障碍的累加效应。
作者：
T. W. Lyttle
分离扭曲 (SD) 染色体的一部分，包括 Sd 和 E(SD) 基因座，已通过插入易位从 SD Roma 移动到 Y(L)。与亲本 SD 染色体相比，该 Dp(2;Y)SD 染色体在导致携带 Rsp(s) 的精子功能障碍的能力方面显示出可忽略不计的降低，这表明即使从其正常的第二染色体环境中移除，SD 仍然可以有效地发挥作用，并且其活性水平不依赖于与正常常染色体同源物的配对。使用该 Dp(2;Y)SD 以及标准 SD 染色体（SD Roma 或 R(SD-36)-1(bw)）以及所有可能的三向组合中的第三个 SD 染色体抑制子 (TM6) 构建了雄性基因型。在每种情况下观察到的 SD 介导的功能障碍水平与假设所有 SD 元素都以加法方式起作用（用 M 表示，精子功能障碍概率的概率变换）而不是乘法作用的模型最为一致。 SD 元件的累加作用与多个 Rsp(s) 拷贝所表现出的对 SD 活性的独立响应形成对比。
A portion of the Segregation distorter (SD) chromosome, including both the Sd and E(SD) loci, has been moved by insertional translocation from SD Roma into Y(L ). This Dp(2;Y)SD chromosome shows a negligible reduction in its ability to cause dysfunction of Rsp( s)-bearing sperm when compared to the parent SD chromosome, suggesting that SD can still act effectively, even when removed from its normal second chromosome milieu, and that its activity level does not depend on pairing with a normal autosomal homologue. Male genotypes have been constructed using this Dp(2;Y)SD along with a standard SD chromosome (either SD Roma or R( SD-36)-1(bw)) and a third chromosome suppressor of SD (TM6) in all possible three-way combinations. The observed level of SD-mediated dysfunction in each case is most compatible with a model that assumes that all SD elements act additively (in terms of M, the probit transformation of the probability of sperm dysfunction), rather than multiplicatively. The additive action of SD elements contrasts with the independent response to SD activity exhibited by multiple Rsp(s) copies.