U.S. Geological Survey, Western Ecological Research Center, San Diego, CA, United States.
Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States.
J Hered. 2023 Jun 22;114(4):410-417. doi: 10.1093/jhered/esad032.
Genome assemblies are increasingly being used to identify adaptive genetic variation that can help prioritize the population management of protected species. This approach may be particularly relevant to species like Blainville's horned lizard, Phrynosoma blainvillii, due to its specialized diet on noxious harvester ants, numerous adaptative traits for avoiding predation (e.g. cranial horns, dorsoventrally compressed body, cryptic coloration, and blood squirting from the orbital sinuses), and status as Species of Special Concern in California. Rangewide decline since the early 20th century, the basis of its conservation status, has been driven mainly by habitat conversion, over-collecting, and invasion of a non-native ant that displaces its native ant prey base. Here, we report on a scaffold-level genome assembly for P. blainvillii as part of the California Conservation Genomics Project (CCGP), produced using Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology. The de novo assembly has 78 scaffolds, a total length of ~2.21 Gb, a scaffold N50 length of ~352 Mb, and BUSCO score of 97.4%. This is the second species of Phrynosoma for which a reference genome has been assembled and represents a considerable improvement in terms of contiguity and completeness. Combined with the landscape genomics data being compiled by the CCGP, this assembly will help strategize efforts to maintain and/or restore local genetic diversity, where interventions like genetic rescue, translocation, and strategic land preservation may be the only means by which P. blainvillii and other low-vagility species can survive in the fragmented habitats of California.
基因组组装越来越多地被用于识别适应性遗传变异,这有助于优先考虑保护物种的种群管理。对于像巴氏角蜥(Phrynosoma blainvillii)这样的物种,这种方法可能特别相关,因为它们的特殊饮食是对有毒的收获蚁,以及许多避免捕食的适应性特征(例如头部角、背腹压缩的身体、隐蔽的颜色和眼眶窦喷射血液),并且在加利福尼亚州被列为特别关注的物种。自 20 世纪初以来,该物种的范围已经下降,这是其保护状况的基础,主要是由于栖息地转换、过度采集以及一种非本地蚂蚁的入侵,这种蚂蚁取代了其本地蚂蚁的猎物基础。在这里,我们报告了巴氏角蜥的支架水平基因组组装,作为加利福尼亚保护基因组学项目(CCGP)的一部分,该组装使用了太平洋生物科学的 HiFi 长读和 Hi-C 染色质接近测序技术。从头组装有 78 个支架,总长度约为 2.21Gb,支架 N50 长度约为 352Mb,且 BUSCO 评分为 97.4%。这是第二个组装了参考基因组的 Phrynosoma 物种,在连续性和完整性方面有了相当大的提高。结合 CCGP 正在汇编的景观基因组学数据,该组装将有助于制定保持和/或恢复当地遗传多样性的策略,在这种情况下,像遗传拯救、转移和战略性土地保护等干预措施可能是巴氏角蜥和其他低迁移性物种在加利福尼亚支离破碎的栖息地中生存的唯一手段。