A New Resource for Characterizing X-Linked Genes in Drosophila melanogaster: Systematic Coverage and Subdivision of the X Chromosome With Nested, Y-Linked Duplications
A New Resource for Characterizing X-Linked Genes in Drosophila melanogaster: Systematic Coverage and Subdivision of the X Chromosome With Nested, Y-Linked Duplications
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DOI：
10.1534/genetics.110.123265
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发表时间：
2010-12-01
期刊：
影响因子：
3.3
通讯作者：
Cook, Kevin R.
中科院分区：
文献类型：
--
作者：
Cook, R. Kimberley;Deal, Megan E.;Cook, Kevin R.
染色体间重复对于X连锁基因的研究尤其重要。男性遗传了一个重要的X连锁基因的突变，除非在基因组的其他地方有一个复制的野生型基因拷贝，否则无法生存。通过重复来挽救X连锁突变的致命性，可以将该突变用于互补测试和其他遗传杂交的实验中，并将突变基因映射到定义的染色体区域。复制也可以用于筛选突变表型的剂量依赖性增强子和抑制子，作为鉴定参与相同生物过程的基因的一种方式。我们描述了一个正在进行的项目，在果蝇产生全面的覆盖面和广泛的断点细分的X染色体与兆碱基规模的X片段承载在Y染色体上。体内方法包括通过FLP-FRT位点特异性重组技术在连接的XY染色体上产生X倒位，然后照射以诱导大的内部X缺失。由此产生的染色体由X尖端、通过倒置置于尖端附近的中间X片段和完整的Y组成。一套嵌套的中间重复段是从每个反转前体衍生出来的。我们已经构建了一套倒置附加XY染色体，使我们能够隔离嵌套重复的片段从所有X区域。到目前为止，我们的筛选已经提供了最低78%的X覆盖率，重复断点间隔的中位数为9个基因。这些重复的染色体将是宝贵的资源，拯救和映射X连锁突变，并确定剂量依赖性修饰突变表型。
Interchromosomal duplications are especially important for the study of X-linked genes. Males inheriting a mutation in a vital X-linked gene cannot survive unless there is a wild-type copy of the gene duplicated elsewhere in the genome. Rescuing the lethality of an X-linked mutation with a duplication allows the mutation to be used experimentally in complementation tests and other genetic crosses and it maps the mutated gene to a defined chromosomal region. Duplications can also be used to screen for dosage-dependent enhancers and suppressors of mutant phenotypes as a way to identify genes involved in the same biological process. We describe an ongoing project in Drosophila melanogaster to generate comprehensive coverage and extensive breakpoint subdivision of the X chromosome with megabase-scale X segments borne on Y chromosomes. The in vivo method involves the creation of X inversions on attached-XY chromosomes by FLP-FRT site-specific recombination technology followed by irradiation to induce large internal X deletions. The resulting chromosomes consist of the X tip, a medial X segment placed near the tip by an inversion, and a full Y. A nested set of medial duplicated segments is derived from each inversion precursor. We have constructed a set of inversions on attached-XY chromosomes that enable us to isolate nested duplicated segments from all X regions. To date, our screens have provided a minimum of 78% X coverage with duplication breakpoints spaced a median of nine genes apart. These duplication chromosomes will be valuable resources for rescuing and mapping X-linked mutations and identifying dosage-dependent modifiers of mutant phenotypes.