中国冠毛鸭（CC鸭）是一种独特的当地产生的水禽品种，其冠状垫影响了其存活率。因此，CC鸭是一个理想的模型来研究维持遗传稳定的遗传补偿反应。本研究首先构建了CC鸭的染色体水平基因组。比较基因组学显示，与组织修复、免疫功能和肿瘤相关的基因受到了强烈的正向选择，表明这些适应性改变可能增强了抗癌能力和免疫应答，以维持CC鸭的遗传稳定性。我们组装了斑嘴鸭（Csp-b鸭）的基因组亚组装，并在三种鸭（即CC鸭、Csp-b鸭和北京鸭）之间检测到基因组的结构变异。功能分析显示，几个结构变异与免疫系统有关，强烈暗示了抗肿瘤和免疫系统的遗传补偿，以进一步支持CC鸭的存活。此外，我们证实CC鸭源自绿头鸭。最后，我们揭示了冠毛特征的生理和遗传基础，并确定了导致冠毛形成的TAS2R40突变。总的来说，本研究的发现为遗传补偿在适应性演化中的作用提供了新的见解。版权所有 © 2023. 由Elsevier B.V.出版。

The Chinese crested (CC) duck is a unique indigenous waterfowl breed, which has a crest cushion that affects its survival rate. Therefore, the CC duck is an ideal model to investigate the genetic compensation response to maintain genetic stability. In the present study, we first generated a chromosome-level genome of CC ducks. Comparative genomics revealed that genes related to tissue repair, immune function, and tumors were under strong positive selection, indicating that these adaptive changes might enhance cancer resistance and immune response to maintain the genetic stability of CC ducks. We sub-assembled a Chinese spot-billed (Csp-b) duck genome and detected genome assembly structural variants among three ducks (i.e., CC duck, Csp-b duck, and Pekin duck). Functional analysis revealed that several structural variants were related to the immune system, which strongly suggests genetic compensation in the anti-tumor and immune systems to further support the survival of CC ducks. Moreover, we confirmed that the CC duck originated from the mallard ducks. Finally, we revealed the physiological and genetic bases of crest traits and identified a causative mutation in TAS2R40 that leads to crest formation. Overall, the findings of this study provide new insights into the role of genetic compensation in adaptive evolution.Copyright © 2023. Published by Elsevier B.V.