Data from: Evolutionary insights of interferon Lambda genes in Tetrapods

Type III interferon, also known as interferon lambda is an innate
antiviral protein. We retrieved the IFN-λ and their receptors’ sequences
belonging to forty-two tetrapod species and conducted computational
evolutionary analysis to understand the gene’s diversity. The CNV of IFN-λ
was determined through qPCR in Indian cattle and buffalo. The tetrapod
species feature intron-containing type-III IFN genes. Some reptiles and
placental mammal have two IFN-λ loci. While marsupials, monotremes, and
birds have a single IFN-λ locus. Some of the placental mammals and
amphibians exhibit multiple IFN-λ genes as intron-less and
intron-containing. Placental mammals typically possess three to four
functional IFN-λ genes, some of them lack signal peptides. IFN-λ of these
tetrapod species formed three major clades. Mammalian IFN-λ4 appears as an
ancestral form, with syntenic conservation in most mammalian species. The
intron-less IFN-λ1 and both the type III IFN receptors have conserved
synteny in tetrapod. Purifying selection was noted in their evolutionary
analysis that plays a crucial role in minimizing genetic diversity and
maintaining the integrity of biological function. This indicates that
these proteins have successfully retained their biological function and
indispensability, even in the presence of the type I IFNs. The expansion
of IFN-λ genes in amphibians and camels have led to the evolution
of multiple IFN-λ. The CNV can arise from gene duplication and conversion
events. The qPCR-based absolute quantification resulted
that IFN-λ3 and IFN-λ4 have more than one copy
in buffalo (Murrah) and six cattle breeds (Sahiwal, Tharparkar, Kankrej,
Red Sindhi, Jersey and Holstein Friesian). Overall, these findings
highlight the evolutionary diversity and functional significance of IFN-λ
in tetrapod species.