Biology subjects

Kanda, R. K.

Publications and source records attributed to Kanda, R. K..

2 recordsLinked to original sources

bioRxiv2026

Abundance, diversity and activity of endogenous retroviruses in the slow loris.

Endogenous retroviruses (ERVs) constitute a significant fraction of vertebrate genomes and serve as genomic records of past retroviral infections, while also influencing host biology through regulatory co-option and, in some cases, ongoing retrotransposition. Despite extensive examination of ERVs in haplorrhine primates, equivalent analyses in strepsirrhines remain absent, leaving a substantial gap in our understanding of ERV diversity and evolutionary dynamics across the primate order. Here, we present the first comprehensive characterisation of ERVs in a strepsirrhine primate, identifying 15 Loris Endogenous Retrovirus (LERV) families encompassing 34 subfamilies and over 6,000 insertions in the Nycticebus coucang reference genome. Phylogenetic analyses resolved LERVs into three retroviral genera: betaretroviruses (LERV1-4), type-D betaretroviruses (LERV5-9), and gammaretroviruses (LERV10-15). LERV2a shows multiple hallmarks of recent or potentially ongoing retrotransposition, including a median insertion age of zero, a high proportion of identical LTR pairs, dN/dS ratios comparable to the active retrovirus HTLV, and insertional polymorphism between two conspecific genomes. Comparative genomic screening across Lorisidae revealed that LERV subfamily distribution broadly mirrors estimated insertion ages, with progressively fewer subfamilies detected in more distantly related species. These findings establish a detailed foundation for understanding retroviral evolution in Strepsirrhini and reveal that ongoing retroviral activity is not restricted to haplorrhine primates.

genomics↗

bioRxiv2024

Novel Endogenous Retroviruses in Anura

Endogenous retroviruses (ERVs) represent remnants of past retroviral infections and have had a pivotal role in vertebrate evolution, contributing toward the generation of novel genes and regulatory elements. The majority of ERV research to date has had a mammalian focus; Anurans (the order of amphibians consisting of frogs and toads) are comparable in genome size and number of extant species and yet very few ERVs have been described in this order. Under the current classification, alpharetroviruses appear to be avian-specific; here we screened 47 publicly available Anuran genomes for alpharetroviruses using a bioinformatic pipeline. Both truncated and full-length ERV elements were identified through this screening process which were represented by multiple loci. Ten families of novel Anuran ERVs (AnERV1-10) with intact viral genes were identified in 11 anuran species, some of which are shared between multiple species. Furthermore, based on conserved domain and phylogenetic analysis, all ten novel ERV families appeared in recombined states. This included two families with alpharetrovirus classified Env proteins, although the majority had epsilonretrovirus classified Pol and gammaretrovirus classified Env proteins. These findings extend the pattern of recombination presented in two other Anuran ERVs and adds to the complex evolutionary history of retroviruses. These results suggest that analysis of other vertebrate groups beyond the mammals would provide new information on the presence and state of ERVs, providing further evidence of the modes of ERV evolution within host genomes and their role in the diversification of the vertebrate tree of life.

genomics↗