Aging and the evolution of the sex-specific chromatin structure in Drosophila

果蝇的衰老与性别特异性染色质 染色质景观是基因调控的关键，但人们对此知之甚少。 它在性别之间或成年后的生活中有何不同。有越来越多的证据 人一生中染色质的变化对细胞 衰老。特别是，在老化的细胞中观察到异染色质的丢失。 包括果蝇在内的几个物种。雄蝇的年龄别死亡率 女性的平均寿命比女性高，平均寿命短。男性也 比女性含有更多的异色DNA，这是因为 存在一个大的富含重复序列的Y染色体，我们的初步数据表明 具有不同表观遗传学特征的性染色体的存在 果蝇(即一种超转录剂量补偿的X染色体， 和沉默的异染色质Y)导致染色质结构的整体变化 性别之间的差异。我们建议比较特定性别的基因表达和 不同性别果蝇种系的表观遗传学特征 染色体核型在他们的寿命，以研究性别的影响- 细胞衰老过程中特定染色质的差异。我们将试验性地修改 参与异染色质维持的基因的蛋白质水平，以直接检测 如果异染色质的形成是性别特异性表观遗传的主要因素 个人资料和寿命。此外，我们将及时分析染色质的状态- 系列样本，并表征老年人与老年人的组织特异性染色质状态。 幼蝇，以解决染色质变化的时间动力学 衰老，以及不同组织间细胞衰老的潜在重要差异。

Aging and the sex-specific chromatin in Drosophila The chromatin landscape is key for gene regulation, but little is known about how it differs between sexes, or over adult life. There is accumulating evidence that chromatin changes during an individual's lifespan contribute to cellular aging. In particular, loss of heterochromatin has been observed in aged cells of several species, including Drosophila. Age-specific mortality rates of male flies are higher and average lifespans are shorter than those of females. Males also contain substantially more heterochromatic DNA than females, due to the presence of a large, repeat-rich Y chromosome, and our preliminary data suggest that the presence of sex chromosomes with different epigenetic profiles in Drosophila (that is, a hyper-transcribed dosage compensated X chromosome, and a silenced heterochromatic Y) result in global changes of chromatin structure between sexes. We propose to compare sex-specific gene expression and epigenetic profiles in Drosophila species and strains with different sex chromosome karyotypes across their lifespan, to study the influence of sex- specific chromatin differences on cellular aging. We will experimentally modify protein levels of genes involved in heterochromatin maintenance, to directly test if heterochromatin formation is a main contributor to sex-specific epigenetic profiles and longevity. Additionally, we will assay chromatin states in time- series samples, and characterize tissue-specific chromatin states in aged vs. young flies, to address the temporal dynamics of changes in chromatin during aging, and potentially important differences in cellular aging across tissues.