Cameroonian fruit bats harbor divergent viruses, including rotavirus H, bastroviruses, and picobirnaviruses using an alternative genetic code

Yinda, Claude Kwe; Ghogomu, Stephen Mbigha; Conceição-Neto, Nádia; Beller, Leen; Deboutte, Ward; Vanhulle, Emiel; Maes, Piet; Van Ranst, Marc; Matthijnssens, Jelle

The identification of these PBV-like RdRp sequences without an apparent capsid is reminiscent to that of mitoviruses (family Narnaviridae), which are known to infect the mitochondria of fungal species (Polashock and Hillman 1994; Hong et al. 1999) . Their genome also consists of a double-stranded RNA element that encodes only an RdRp but does not form encapsulated viral particles. This virus genome is transmitted horizontally through mating (anastomosis) or vertically from mother to daughter cells (Shackelton and Holmes 2008) . Apart from mitoviruses, only damselfish virus-like agents (a DNA virus) are known to infect mitochondria, although their mode of replication and transmissions is yet to be delineated (Schmale et al. 2009 ). To further investigate if indeed these PBV-like strains could be infecting the mitochondrion, we performed a principle component analysis (PCA) of the codon usage bias of different known mitochondrial genome sequences, mitoviruses, classical PBVs and PBV-like viruses using an alternative genetic code (Shi et al. 2016 ). Based on this analysis, the four PBV-like sequences identified in this study (P11-300, P11-378, P14-90, and P15-218) clustered closely together with other viruses using the alternative genetic code, such as mitoviruses, and other in crustacean/insect PBV-like viruses (Fig. 4B ). The Cameroonian strain P16-366, clustered more closely with mitochondrial genomes (Fig. 4B) . Most of the PBVs using a standard genetic code, clustered away from sequences using the alternative genetic codes, although there were some exceptions.