High genetic instability of heterochromatin after transposition of the LINE-like I factor in Drosophila melanogaster
High genetic instability of heterochromatin after transposition of the LINE-like I factor in Drosophila melanogaster
复制标题
DOI：
10.1073/pnas.94.15.8052
复制
发表时间：
1997-07-22
影响因子：
11.1
通讯作者：
Mei, E
中科院分区：
文献类型：
--
作者：
Dimitri, P;Arca, B;Mei, E
在目前的工作中，我们已经询问了一组13个定位于黑胃果蝇2号染色体异染色质的必要基因是否在I- r杂交发育过程中I因子的转位后是可变的。我们发现，尽管与常染色质相比，在2号染色体异染色质中发现的遗传功能密度较低，但致命事件映射到该区域的频率却惊人地高。细胞遗传学和分子遗传学分析表明，这些突变可能与插入或重排有关。此外，携带特异性异染色质致死突变的染色体是由异染色质中的重组产生的。这些数据表明，I因子高频转置到2号染色体的中心周围区域，并可能在组成性异染色质的进化中发挥作用。
In the present work, we have asked whether a group of 13 essential genes mapping to the heterochromatin of Drosophila melanogaster chromosome 2 are mutable following transposition of the I factor during I-R hybrid dysgenesis. We found that the frequency of lethal events mapping to chromosome 2 heterochromatin is surprisingly high, despite the low density of genetic functions identified in this region compared with euchromatin. Cytogenetic and molecular analyses indicated that the recovered mutations correspond either to insertions or to rearrangements, Moreover, chromosomes bearing specific heterochromatic lethal mutations were generated by recombination in the heterochromatin, Together, these data indicate that I factors transpose with high frequency into pericentric regions of chromosome 2 and may play a role in the evolution of constitutive heterochromatin.