A chromosome‐level genome assembly of Brachymystax lenok tsinlingensis
provides new insights into salmonids evolution
The salmonid-specific fourth vertebrate whole-genome duplication (Ss4R)
occurred ~80 million years ago in the ancestor of all
salmonids and provides a unique opportunity to study the evolutionary
history of the duplicated genome. Study of the genome of Brachymystax
lenok tsinlingensis might be particularly insightful given that this is
the only Brachymystax species with a published salmonid genome. Here, we
present a high-quality chromosome-level genome assembly for B. l.
tsinlingensis and found that the salmonids have a unique GC content and
codon usage, have undergone a whole-genome duplication event and a burst
of transposon-mediated repeat expansion, have a slower evolutionary
rate, and possess specific expanded gene families and unique positively
selected genes. Generally, the B. l. tsinlingensis genome could provide
a valuable reference for the study of other salmonids as well as aid the
conservation of this endangered species.