"Gene Trafficking on an Evolving X Chromosome in Drosophila"

基因在基因组中是非随机分布的。从全基因组表达谱中出现的一个有趣的模式是具有性别偏好表达的基因，即在性别之间差异表达的基因在性染色体上显示出有偏见的分布。特别是，雄性偏向基因从果蝇的X染色体中被耗尽，使得X染色体变得去雄性化。男性偏好基因的缺失可以部分解释为男性基因从X染色体上移动。这些模式背后的进化力量是有争议的，可能涉及男性生殖系X失活，性拮抗，或剂量补偿机制。果蝇米兰达-一个物种，我们最近产生了从头基因组序列组装-有一个新形成的性染色体系统。它的neo-Y染色体正处于从普通常染色体向简并Y染色体的转变过程中。作为回应，neo-X正在进化分化X的刻板特性，包括获得部分剂量补偿，以及-如初步数据所示-源自其neo-X的过量基因易位。D.因此，米兰达提供了一个独特的系统，研究机制的基因贩运的一个不断演变的X染色体和其演变的原因，在行动中使用比较和功能基因组学的方法。

Genes are distributed non-randomly across the genome. One intriguing pattern to emerge from genome-wide expression profiling is that genes with sex-biased expression that is, genes that are differentially expressed between the sexes show a biased distribution on sex chromosomes. In particular, male-biased genes are depleted from the Drosophila X chromosome, such that the X has become demasculinized. The deficiency of male-biased genes can partly be explained by movement of male genes off the X chromosome. The evolutionary forces underlying these patterns are controversial and may involve male germline X inactivation, sexual antagonism, or dosage compensation mechanisms. Drosophila miranda - a species for which we recently generated a de novo genome sequence assembly - has a newly formed sex chromosome system. Its neo-Y chromosome is in transition from an ordinary autosome to a degenerate Y. In response, the neo-X is evolving the stereotypical properties of a differentiated X, including the acquisition of partial dosage compensation and - as suggested by preliminary data - an excess of gene translocations originating from its neo-X. D. Miranda therefore provides a unique system to study the mechanisms of gene trafficking on an evolving X chromosome and its evolutionary causes in action using a comparative and functional genomics approach.