荒漠特有地鸦属鸟类的适应性进化研究

自达尔文时代起，适应性进化一直是进化生物学和生态学领域研究的重要科学问题之一。全球气候变化对物种的生存影响很大，特别是对于极端环境分布的物种。近年来动物对青藏高原极端环境的适应进化有广泛而深入的研究，而较少关注荒漠极端环境的适应问题。地鸦属鸟类全世界有4种，包括白尾地鸦（我国塔克拉玛干沙漠特有种）、黑尾地鸦、波斯地鸦和里海地鸦，均为典型的干旱荒漠特有种，且与远缘的青藏高原地山雀存在明显的表型趋同（如长而下弯的喙、较长的跗趾和接近环境背景的沙褐色体羽等）。本项目拟选择地鸦类为研究对象，采用三代测序技术构建两个高质量基因组（地鸦属两个支系各一个代表物种，即白尾地鸦和波斯地鸦），并运用比较基因组学方法，从位点、基因、基因家族、生物功能和通路等多个角度检测这些物种如何适应荒漠极端环境，挖掘其与地山雀表型趋同的分子遗传机制。研究结果对于理解物种如何适应荒漠极端环境、如何趋同演化具有重要的科学意义。

Since the Darwin era, adaptive evolution has been one of the important scientific issues in the fields of evolutionary biology and ecology. Global climate change has a considerable impact on species. In particular, the influence of climate change on animals is exacerbated in extreme environments. Recently, there have been extensive and in-depth studies on how animals adapted to the Qinghai-Tibet Plateau, while few studies have explored the desert adaptation. There are 4 Podoces species recognized globally which are endemic to the arid deserts and have obvious phenotypic convergence with the distantly related species, the ground tit (Pseudopodoces humilis) that is native to the Qinghai-Tibet Plateau (such as the long and decurved beak, long tarsus, and sand-brown feather). In this study, we aim to firstly assemble the high-quality genome of two Podoces species (one representative species in each of the two branches of Podoces, i.e., Podoces biddulphi and Po. pleskei) using third-generation sequencing, and then detect the signals of the desert adaptations of the species, and finally explore the convergent mechanisms of the phenotypes between Podoces and the ground tit at the levels of the locus, gene, gene family, and biological function and pathway by a comparative genomic approach. These findings will greatly facilitate the understanding of desert adaptation and convergent evolution.