Day Grace, Robb Kate, Oxley Andrew, Telonis-Scott Marina, Ujvari Beata
School of Life and Environmental Sciences, Deakin University, Geelong 3216, VIC, Australia.
Marine Mammal Foundation, Melbourne 3194, VIC, Australia.
iScience. 2024 Mar 27;27(4):109590. doi: 10.1016/j.isci.2024.109590. eCollection 2024 Apr 19.
A quarter of marine mammals are at risk of extinction, with disease and poor habitat quality contributing to population decline. Investigation of the Major Histocompatibility Complex (MHC) provides insight into species' capacity to respond to immune and environmental challenges. The eighteen available cetacean chromosome level genomes were used to annotate MHC Class I loci, and to reconstruct the phylogenetic relationship of the described loci. The highest number of loci was observed in the striped dolphin (), while the least was observed in the pygmy sperm whale () and rough toothed dolphin (). Of the species studied, Mysticetes had the most pseudogenes. Evolutionarily, MHC Class I diverged before the speciation of cetaceans. Yet, locus one was genomically and phylogenetically similar in many species, persisting over evolutionary time. This characterisation of MHC Class I in cetaceans lays the groundwork for future population genetics and MHC expression studies.
四分之一的海洋哺乳动物面临灭绝风险，疾病和恶劣的栖息地质量导致其数量下降。对主要组织相容性复合体（MHC）的研究有助于深入了解物种应对免疫和环境挑战的能力。利用18个已有的鲸类染色体水平基因组对MHC I类基因座进行注释，并重建所描述基因座的系统发育关系。在条纹海豚中观察到的基因座数量最多，而在侏虎鲸和糙齿海豚中观察到的数量最少。在所研究的物种中，须鲸类的假基因最多。在进化上，MHC I类在鲸类物种形成之前就已经分化。然而，在许多物种中，基因座1在基因组和系统发育上是相似的，并且在进化过程中一直存在。对鲸类MHC I类的这种特征描述为未来的种群遗传学和MHC表达研究奠定了基础。
