2.2 Phylogenetic analysis
The phylogenetic tree of all 164 species and 38 selected species was
constructed by MEGA X[15] using the
neighbor-joining (NJ) method with 1000 bootstrap replicates. Multiple
sequences alignment used for phylogenetic tree construction was
generated by the MAFFT software[16]
with default parameters. We further searched
for conserved
domains within human TMPRSS2 protein against the NCBI’s CDD v3.18 –
55570 PSSMs database[17] by setting
the expected value threshold of 0.01 and 500 maximum number of hits. We
then constructed a phylogenetic tree using protein sequences of domain
regions by use of the same NJ method as the whole amino sequences.