Zhu Lifeng, Deng Cao, Zhao Xiang, Ding Jingjing, Huang Huasheng, Zhu Shilin, Wang Zhiwen, Qin Shishang, Ding Yuhua, Lu Guoqing, Yang Zhisong
College of life Sciences Nanjing Normal University Nanjing China.
University of Nebraska at Omaha Omaha.
Evol Appl. 2018 Oct 9;11(10):2040-2053. doi: 10.1111/eva.12705. eCollection 2018 Dec.
The Milu (Père David's deer, ) were once widely distributed in the swamps (coastal areas to inland areas) of East Asia. The dramatic recovery of the Milu population is now deemed a classic example of how highly endangered animal species can be rescued. However, the molecular mechanisms that underpinned this population recovery remain largely unknown. Here, different approaches (genome sequencing, resequencing, and salinity analysis) were utilized to elucidate the aforementioned molecular mechanisms. The comparative genomic analyses revealed that the largest recovered Milu population carries extensive genetic diversity despite an extreme population bottleneck. And the protracted inbreeding history might have facilitated the purging of deleterious recessive alleles. Seventeen genes that are putatively related to reproduction, embryonic (fatal) development, and immune response were under high selective pressure. Besides, a gene involved in controlling reabsorption of sodium in the body, was positively selected. An additional 29 genes were also observed to be positively selected, which are involved in blood pressure regulation, cardiovascular development, cholesterol regulation, glycemic control, and thyroid hormone synthesis. It is possible that these genetic adaptations were required to buffer the negative effects commonly associated with a high-salt diet. The associated genetic adaptions are likely to have enabled increased breeding success and fetal survival. The future success of Milu population management might depend on the successful reintroduction of the animal to historically important distribution regions.
麋鹿（大卫神父鹿）曾广泛分布于东亚的沼泽地（从沿海地区到内陆地区）。麋鹿种群数量的显著恢复如今被视为拯救极度濒危动物物种的经典范例。然而，支撑这一种群恢复的分子机制在很大程度上仍不为人知。在此，我们运用了不同方法（基因组测序、重测序和盐度分析）来阐明上述分子机制。比较基因组分析表明，尽管经历了极端的种群瓶颈，最大的恢复后的麋鹿种群仍具有广泛的遗传多样性。而且长期的近亲繁殖历史可能促进了有害隐性等位基因的清除。17个与繁殖、胚胎（致命）发育和免疫反应可能相关的基因处于高选择压力之下。此外，一个参与控制体内钠重吸收的基因受到了正选择。还观察到另外29个基因受到正选择，它们涉及血压调节、心血管发育、胆固醇调节、血糖控制和甲状腺激素合成。这些遗传适应可能是为了缓冲通常与高盐饮食相关的负面影响。相关的遗传适应可能使繁殖成功率和胎儿存活率得以提高。麋鹿种群管理未来的成功可能取决于将这种动物成功重新引入历史上重要的分布区域。
