Discussion
B.
l. tsinlingensis belongs to Brachymystax , which is the most
ancient species of salmonid fish. Its genomic resources not only provide
new insights into its evolution but also supply basic data for future
studies of salmonid evolution. We presented the first chromosome-level
genome assembly of B. l. tsinlingensis with an N50
~50.15 Mb. Several different methods confirmed the high
quality and accuracy of the assembled genome. Comparison of the genome
of B. l. tsinlingensis with that of other salmonids revealed that
the basic genome characters of salmonids were similar after the Ss4R
event. Ss4R also caused an increase in TEs in salmonids and the number
of genes, and several positively selected genes were specific to
salmonids. The evolutionary rate of all salmonids was slower compared
with other species. In addition, there is a pressing need to protect
these endangered species. Habitat conservation for B. l.
tsinlingensis is particularly important for ensuring the long-term
survival and viability of B. l. tsinlingensis populations.