First reference genome assembly of the Indochinese silvered langur (Trachypithecus germaini).

DEAR EDITOR, Of the seven genera recognized in Asian colobines,Trachypithecus is the only genus that contains species groups.Compared with the species groups characterized by calcium tolerance(T.francoisi species group),multi-male,multi-female society(T.obscurus species group),and impressive hybridization(T.pileatus species group),the T.cristatus species group is distinguished by its southernmost distribution and silvery appearance.Hence,Trachypithecus is an excellent model for investigating evolutionary radiation and behavioral adaptation in Asian primates.However,comprehensive comparison of species groups remains difficult due to the lack of a reference genome for the T.cristatus species group.In the current study,based on Nanopore sequencing,we produced a high-quality de novo assembly of the Indochinese silvered langur(Trachypithecus germaini)genome as a representative of the T.cristatus species group.The assembled genome was 2.91 Gb in size,with a contig N50 of 55.90 Mb.The genome was predicted to contain 20 332 protein-coding genes,and genome synteny analysis between T.germaini and T.francoisi indicated a good collinear relationship.Demographic history analysis indicated that the T.germaini population declined during glacial periods,possibly due to climate change and human activity.The high-quality genome of the Indochinese silvered langur should provide a valuable resource for a deeper understanding of the natural history and social evolution of Trachypithecus spp.,as well as adaptive radiation in primates.