飞行脊椎动物染色质空间构象及开放性趋同研究

飞行的出现使得动物成功的占领了空中生态位，实现了由陆地进化到天空的飞跃，极大的拓展了动物的生存空间。在2亿年的进化历史中，就有三个脊椎动物类群先后独立进化出了飞行能力，它们分别是已经灭绝的翼龙、现生鸟类和蝙蝠。飞行能力的获得需要生物体发生一系列的形态结构和生理变化，以满足飞行的巨大能量需求。研究表明，这三类飞行脊椎动物在形态结构和生理表型上展现出了高度的趋同进化现象。这些形态和生理上的趋同应该具有遗传学的基础。的确，在遗传上，飞行脊椎动物独立表现出了基因组缩小的现象。然而，它们独立发生的基因组缩小与其形态或生理趋同之间的相互关系并未清楚。鉴于此，本研究聚焦飞行脊椎动物基因组缩小这一重大进化事件，采用比较基因组学的手段，探究这一趋同现象是否会导致染色质开放状态及其空间构象发生趋同进化，进而考察其是否导致趋同的基因表达调控模式，以探讨形态结构和生理功能趋同进化的可能分子机制。

The acquisition of flight has allowed animals to successfully occupy the air niche, largely expanding their living space. Upon 200 million years’ evolution, three vertebrate clades referring to extinct pterosaurs, living birds and bats, have independently evolved their flight abilities. The acquisition of flight capability requires a series of morphological and physiological changes to meet the huge energy requirements during flight. Studies have shown that these three flying vertebrates exhibit strong convergent evolution in both morphologies and physiologies. These morphological and physiological convergences should have common genetic basis. Indeed, flying vertebrates have independently evolved a shrinking genome. However, studies addressing how the independently occurred genome shrinkage leads to the observed morphological or physiological convergence are still lacking. As a result, this study will use comparative genomics approaches to explore whether the convergence of genome shrinkage lead to the convergence of the chromatin opening state and conformation, which results in convergence of gene expression regulation, and finally giving rise to the morphological and physiological convergences.