Ioly Kotta-Loizou | PubMed Health

PubMed2026

Detection of dsRNA in Soil-Derived Ascomycetes and Characterization of Cladosporium cladosporioides Partitivirus 1 Isolate IPBL11.

Mycoviruses can induce phenotypic and physiological changes in their fungal hosts, making them valuable biological resources. To harness this potential, it is crucial to gather comprehensive information on their distribution patterns, genomic and structural characteristics, and interactions with host fungi. In this study, we screened 64 ascomycete isolates collected from various soil environments in Korea to detect the presence of double-stranded RNA (dsRNA) elements. We identified dsRNA bands in three of these isolates. Among them, we determined the complete genome sequence of a bipartite dsRNA virus found in Cladosporium anthropophilum. Phylogenetic analyses based on the RNA-dependent RNA polymerase (RdRP) and capsid protein (CP) sequences indicated that this virus belongs to the genus Gammapartitivirus within the family Partitiviridae. Comparative sequence analyses suggested that this virus is best classified as a new isolate of Cladosporium cladosporioides partitivirus 1, which we designated as Cladosporium cladosporioides partitivirus 1 isolate IPBL11 (CcPV1-IPBL11).

Cladosporium anthropophilum↗

PubMed2026

Conserved host-exclusive oligonucleotide motifs enriched in pathogenic genes of human oncogenic viruses.

Comparative viral genomics can reveal sequence-level constraints influencing virus-host interactions. Relative minimal absent words (rMAWs) are short oligonucleotide motifs present in viral genomes but completely absent from the host, potentially reflecting selective pressures related to host adaptation and immune evasion. Using the EAGLE algorithm and the GRCh38 human reference genome, we systematically screened for prevalent rMAWs (prMAWs) across six major human oncogenic viruses: Epstein-Barr virus (EBV), hepatitis B virus (HBV), hepatitis C virus (HCV), human papillomavirus (HPV), human T-cell leukemia virus type 1 (HTLV-1), and human herpesvirus 8/Kaposi's sarcoma-associated herpesvirus (HHV-8/KSHV). highly conserved 11- and 12-bp prMAWs were identified in EBV, HBV, HTLV-1, and HHV-8/KSHV, with sequence prevalences ranging from 91.5% to 97.9%. Conversely, no short prMAWs were detected in HCV or HPV, likely reflecting differences in genome architecture, mutation rates, and long-term host adaptation to the human host. Importantly, the identified host-exclusive motifs exhibited non-random genomic distribution and were preferentially embedded within viral genes central to replication, persistence, immune modulation, and oncogenesis, including EBNA-1 (EBV), HBx (HBV), Tax-associated regions (HTLV-1), and lytic replication genes of HHV-8/KSHV. Notably, all detected prMAWs were enriched in GC nucleotides and exhibited marked CpG over-representation, suggesting sequence constraints associated with epigenetic regulation and viral persistence. Collectively, these highly conserved, host-exclusive signatures offer promising, candidates for sequence-directed approaches in the diagnosis, monitoring, and investigation of virus-associated cancers.

Humans↗