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Hydatigera kamiyai (H. kamiyai) is a new species within Hydatigera that has recently been resurrected. Voles and cats are hosts of H. kamiyai and have a certain impact on its health and economy. Moreover, the Qinghai-Tibetan plateau (QTP) is a research hotspot representing Earth's biodiversity, as its unique geographical environment and climatic conditions support the growth of a variety of mammals and provide favorable conditions for various parasites to complete their life history. The aim of this study was to reveal the phylogenetic relationships and divergence times of H. kamiyai strains isolated from Neodon fuscus on the QTP using morphological and molecular methods. In this study, we morphologically observed H. kamiyai and sequenced the whole mitochondrial genome. Then, we constructed phylogenetic trees with the maximum likelihood (ML) and Bayesian inference (BI) methods. The GTR alternative model was selected for divergence time analysis. These data demonstrated that the results were consistent with the general morphological characteristics of Hydatigera. The whole genome of H. kamiyai was 13,822 bp in size, and the A + T content (73%) was greater than the G + C content (27%). The Ka/Ks values were all <1, indicating that all 13 protein-coding genes (13 PCGs) underwent purifying selection during the process of evolution. The phylogenetic tree generated based on the 13 PCGs, cytochrom oxidase subunit I (COI), 18S rRNA and 28S rRNA revealed close phylogenetic relationships between H. kamiyai and Hydatigera , with high node support for the relationship. The divergence time based on 13 PCGs indicated that H. kamiyai diverged approximately 11.3 million years ago (Mya) in the Miocene. Interestingly, it diverged later than the period of rapid uplift in the QTP. We also speculated that H. kamiyai differentiation was caused by host differentiation due to the favorable living conditions brought about by the uplift of the QTP. As there have been relatively few investigations on the mitochondrial genome of H. kamiyai , our study could provide factual support for further studies of H. kamiyai on the QTP. We also emphasized the importance of further studies of its hosts, Neodon fuscus and cats, which will be important for further understanding the life cycle of H. kamiyai. • Hydatigera kamiyai (H. kamiyai) was found for the first time in the Qinghai-Tibetan Plateau (QTP). • Complete mitochondrial genome of H. kamiyai was obtained, providing valuable data for further studies. • H. kamiyai had the potential for zoonosis. [ABSTRACT FROM AUTHOR]

Bufavirus (BuV) was first identified in feces from children with acute diarrhea, and a genetically related Canine bufavirus (CBuV) was first reported in Italy in 2018. In this study, through the investigation of CBuV in 622 anal swabs from dogs with diarrhea symptoms collected from various provinces in northern, central and eastern China during 2018–2022, 14 samples were detected to be positive. And 5 samples were from dogs co-infected with other canine diarrhea related viruses, which consist of CPV-2, CDV and CCoV. The complete genome sequences (4219 nt) of the fourteen strains were amplified and sequenced. Through comparative analysis with 51 reference BuV strains, six strains might recombinate from the CBuV strains (HUN/2012/22, CaBuV/9AS/2005/ITA and CaBuV/35/2016/ITA) in Hungary and Italy as the parents, and two genetic recombination events from various parents were predicted to occur on the BUV-422 strain. Combined analyzing the phylogenetic tree and sequence alignment, it was found that these CBuVs are highly conserved in the nonstructural protein NS1, but indeed various amino acid mutation sites in the capsid protein VP2, and even some amino acid sites coincide with putative protein plastic regions and potential epitopes. The BUV-422 and BUV-512 strains show sequential mutation sites identical to the divergent strains of CaBuV/9AS/2005/ITA and CaBuV/35/2016/ITA. This study would enrich the molecular data of CBuV in China and provide essential reference for the epidemiological research and vaccine development of CBuV in the future. • The CBuV phylogenetic branch is only closely related to PBuV and HBuV. • Six obtained Chinese CBuVs might recombinate from the CBuV strain in Hungary and Italy. • Two genetic recombination events from various parents were predicted to occur on the BUV-422 strain. • The BUV-422/512 strains show sequential mutation sites identical to the variant Italian strains. [ABSTRACT FROM AUTHOR]

Decapod hepandensovirus 1 (DHPV) is a viral pathogen that causes growth retardation and decreased feed conversion efficiency in penaeid shrimp. The virus exhibits high genetic variation between different hosts and geographical locations. It has been primarily reported in cultured Penaeus monodon , P. chinensis , and P. merguiensis , and a new type of DHPV has recently been reported in P. vannamei cultured in Korea and Taiwan. In this study, the genome of a recently reported new type of DHPV was fully sequenced by conventional Sanger sequencing combined with a next-generation sequencing approach. Similar to the other types of DHPVs infecting several shrimp species other than P. vannamei , a new type of DHPV contained a linear, single-stranded DNA genome of 6173 bp comprising three major open reading frames. However, by detailed comparative genome and phylogenetic analysis, the virus was not clustered with the pre-existing genotypes, suggesting the emergence of a possible novel genotype of DHPV in cultured shrimps. This study is the first to report the complete genomic sequence of DHPV identified in P. vannamei. • A new genotype of Decapod hepandensovirus 1 (DHPV) is found in Penaeus vannamei. • Complete genome sequence of DHPV infecting Penaeus vannamei presented in the study. • The DNA genome is 6173 bp in size, comprising 3 major open reading frames (ORFs). • ORF 3 region of the new DHPV shows notably low similarity to 9 historic viruses. • The phylogenetic tree shows the new DHPV doesn't cluster with existing genotypes. [ABSTRACT FROM AUTHOR]