Cenci Giovanni, Belloni Giorgio, Dimitri Patrizio
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Ecotekne, Università di Lecce, Via Lecce-Monteroni, 73100 Lecce, Italy.
Genet Res. 2003 Feb;81(1):15-24. doi: 10.1017/s0016672302006018.
Genetic and cytological approaches have yielded significant insight into the mapping and organization of genes located in the heterochromatin of Drosophila melanogaster. To date, only a few of these genes have been molecularly characterized in detail, and their function unveiled. As a further step towards the identification of heterochromatic gene functions, we have carried out a cytological analysis of mitotic and meiotic cell divisions in mutants carrying different allelic combinations of 1(2)41Aa, a gene located in the proximal heterochromatin of chromosome 2. Our results showed that larval brains of 1(2)41Aa mutants display a high frequency of cells with irregularly condensed chromosomes. In addition, defective chromosome condensation was detected in male meiosis, consequently affecting chromosome segregation and giving rise to irregular spermatids. Taken together, these findings indicate that 1(2)41Aa is a novel cell cycle gene required for proper chromosome condensation in both somatic and germ line cells.
遗传学和细胞学方法已经让我们对位于黑腹果蝇异染色质中的基因图谱和组织有了重要的认识。到目前为止，这些基因中只有少数得到了详细的分子特征描述，其功能也得以揭示。作为进一步鉴定异染色质基因功能的步骤，我们对携带位于2号染色体近端异染色质的基因1(2)41Aa不同等位基因组合的突变体进行了有丝分裂和减数分裂细胞分裂的细胞学分析。我们的结果表明，1(2)41Aa突变体的幼虫大脑中出现染色体凝聚不规则的细胞的频率很高。此外，在雄性减数分裂中检测到染色体凝聚缺陷，从而影响染色体分离并产生不规则的精子细胞。综上所述，这些发现表明1(2)41Aa是一个新的细胞周期基因，在体细胞和生殖细胞中正常染色体凝聚均需要该基因。
