Diversity and potential host-interactions of gut viruses in the
black-necked crane (Grus nigricollis)
Abstract
Less is known about the interaction of viruses with their prokaryotic
host in the gut of wild animal. Here we used fecal DNA metagenomic data
(n = 24) from black-necked cranes during the wintering period for virus
characterization. The results were found to be consistent with the trend
of bacterial community changes, and the black-necked crane gut viruses
community structure was conservative during the wintering period. A
total of 280 vOTUs (6 complete, 3 HQ, 2 MQ and 269 LQ) were obtained and
life history predictions identified 207 virulent viruses. 269 LQ vOTUs
contained at least 10 viral genes, hence several of these viruses may be
too distinct from viral species in the CheckV database to properly
estimate their completeness. Meanwhile, gene-sharing network analysis
revealed that the gut viruses of black-necked crane formed 32 unique
viral clusters (VCs). Virus taxonomic assignment has revealed that
Azeredovirinae is the most abundant family during the wintering period
of black-necked cranes. Furthermore. Black-necked crane gut viruses have
a complex relationship with their prokaryotic hosts, and virus-encoded
auxiliary metabolic genes (AMGs) enhance the potential of infecting
bacteria for chitin degradation, methionine and tetrahydrofolate (THF)
metabolism. These results imply the presence of a large number of novel
viruses in the intestinal tract of black-necked cranes, which may
further affect birds by regulating prokaryotic bacterial metabolism
including lyse prokaryotic host cells and encodes AMGs related to the
degradation of complex carbohydrates and amino acid metabolism.