Genetic and molecular analysis of wings apart-like (wapl), a gene controlling heterochromatin organization in Drosophila melanogaster.
Genetic and molecular analysis of wings apart-like (wapl), a gene controlling heterochromatin organization in Drosophila melanogaster.
复制标题
翅膀分离样 (wapl) 的遗传和分子分析，这是一种控制黑腹果蝇异染色质组织的基因。
DOI：
10.1093/genetics/154.4.1693
复制
发表时间：
2000
期刊：
影响因子：
3.3
通讯作者：
Gatti,M
中科院分区：
文献类型：
--
作者：
Vernì,F;Gandhi,R;Goldberg,ML;Gatti,M
X连锁基因翼分离样（wapl）的突变导致与异常染色体形态相关的晚期幼虫致死。在wapl突变体的脑细胞中期，所有染色体的姐妹染色单体彼此平行排列，而不是呈现在野生型中观察到的典型形态。这种效应是由于染色体异染色质区的姐妹染色单体之间的粘附力减弱所致。尽管这种异常的染色体形态，突变的大脑表现出正常的有丝分裂参数，这表明异染色质凝聚力是不必要的适当的着丝粒功能。在这些观察的基础上，我们研究了wapl在女性减数分裂染色体分离中的作用。wapl在非交叉体分离上表现出明显的显性效应，进一步支持了近端异染色质参与雌性减数分裂期间染色体配对的假设。我们还研究了wapl是否调节位置效应杂色（PEV）。我们的分析表明，wapl是一个显性抑制白色和留茬杂色，而它是一个弱的增强棕色杂色。wapl定位于Pgd和pn之间的X染色体的2D区域。我们在该区域先前进行的染色体步移中鉴定了wapl基因。wapl转录单位产生两个可变剪接的转录物6.5-和5-kb长。由这些转录物中较大的转录物编码的蛋白质似乎在高等真核生物中是保守的，并且含有一系列酸性氨基酸，使人想起许多染色质相关蛋白，包括由其他基因编码的两种[HP 1和SU（VAR）3-7]，这些基因作为PEV的抑制因子。
Mutations in the X-linked gene wings apart-like (wapl) result in late larval lethality associated with an unusual chromosome morphology. In brain cell metaphases of wapl mutants, sister chromatids of all chromosomes are aligned parallel to each other instead of assuming the typical morphology observed in wild type. This effect is due to a loosening of the adhesion between sister chromatids in the heterochromatic regions of the chromosomes. Despite this aberrant chromosome morphology, mutant brains exhibit normal mitotic parameters, suggesting that heterochromatin cohesion is not essential for proper centromere function. On the basis of these observations, we examined the role of wapl in meiotic chromosome segregation in females. wapl exhibits a clear dominant effect on achiasmate segregation, giving further support to the hypothesis that proximal heterochromatin is involved in chromosome pairing during female meiosis. We also examined whether wapl modulates position-effect variegation (PEV). Our analyses showed that wapl is a dominant suppressor of both white and Stubble variegation, while it is a weak enhancer of brown variegation. wapl maps to region 2D of the X chromosome between Pgd and pn. We identified the wapl gene within a previously conducted chromosomal walk in this region. The wapl transcriptional unit gives rise to two alternatively spliced transcripts 6.5- and 5-kb long. The protein encoded by the larger of these transcripts appears to be conserved among higher eukaryotes and contains a tract of acidic amino acids reminiscent of many chromatin-associated proteins, including two [HP1 and SU(VAR)3-7] encoded by other genes that act as suppressors of PEV.