Viral diversity in wild and urban rodents of Yunnan Province, China.

Rodents represent over 40% of known mammal species and are found in various terrestrial habitats. They are significant reservoirs for zoonotic viruses, including harmful pathogens such as arenaviruses and hantaviruses, yet knowledge of their hosts and distributions is limited. Therefore, characterizing the virome profile in these animals is invaluable for outbreak preparedness, especially in potential hotspots of mammal diversity. This study included 681 organs from 124 rodents and one Chinese tree shrew collected from Yunnan Province, China, during 2020-2021. Metagenomic analysis revealed unique features of mammalian viruses in rodent organs across habitats with varying human disturbances. R. tanezumi in locations with high anthropogenic disturbance exhibited the highest mammal viral diversity, with spleen and lung samples showing the highest diversities for these viruses at the organ level. Mammal viral diversity for both commensal and non-commensal rats was identified to positively correlate with landscape disturbance. Some virus families were associated with particular organs or host species, suggesting tropism for these pathogens. Notably, known and novel viral species that are likely to infect humans were identified. R. tanezumi was identified as a reservoir and carrier for various zoonotic viruses, including porcine bocavirus, hantavirus, cardiovirus, and lyssavirus. These findings highlight the influence of rodent community composition and anthropogenic activities on diverse virome profiles, with R. tanezumi as an important reservoir for zoonotic viruses.

Virome characterization and identification of a putative parvovirus and poxvirus in bat ectoparasites of Yunnan Province, China.

Ectoparasites found on bats are known to contain important microbes. However, the viruses hosted by these obligate parasites are understudied. This has led to the near oversight of the potential role of these ectoparasites in virus maintenance and transmission from bats to other interacting species and the environment. Here, we sampled bat ectoparasites parasitizing a diverse selection of bat species in the families Rhinolophidae, Vespertilionidae, Megadermatidae, Hipposideridae and Pteropodidae in Yunnan Province, China. We show that the ectoparasite prevalence was generally higher in male compared to female bats. Most ectoparasites were found to fall within the Nycteribiidae, Spinturnicidae and Streblidae bat ectoparasite families. We subsequently applied a non-biased sequencing of libraries prepared from the pooled ectoparasites, followed by an in-silico virus-centric analysis of the resultant reads. We show that ectoparasites hosted by the sampled families of bats are found to carry, in addition to a diverse set of phages, vertebrate and insect viruses in the families Aliusviridae, Ascoviridae, Chuviridae, Circoviridae, Flaviviridae, Hepadnaviridae, Hepeviridae, Herpesviridae, Iridoviridae, Marseilleviridae, Nairoviridae, Orthomyxoviridae, Parvoviridae, Poxviridae, Reoviridae, Retroviridae, and Rhabdoviridae. We further report a partial Parvovirus VP1/VP2 gene and partial Poxvirus ubiquitin-like gene predicted by two independent next generation sequencing data analysis pipelines. This study describes the natural virome of bat ectoparasites, providing a platform for understanding the role these ectoparasites play in the maintenance and spread of viruses to other animals.

Recombinant chimpanzee adenovirus vector vaccine expressing the spike protein provides effective and lasting protection against SARS-CoV-2 infection in mice.

SARS-CoV-2 infection is a global public health threat. Vaccines are considered amongst the most important tools to control the SARS-CoV-2 pandemic. As expected, deaths from SARS-CoV-2 infection have dropped dramatically with widespread vaccination. However, there are concerns over the duration of vaccine-induced protection, as well as their effectiveness against emerging variants of concern. Here, we constructed a recombinant chimpanzee adenovirus vectored vaccine expressing the full-length spike of SARS-CoV-2 (AdC68-S). Rapid and high levels of humoral and cellular immune responses were observed after immunization of C57BL/6J mice with one or two doses of AdC68-S. Notably, neutralizing antibodies were observed up to at least six months after vaccination, without substantial decline. Single or double doses AdC68-S immunization resulted in lower viral loads in lungs of mice against SARS-CoV-2 challenge both in the short term (21 days) and long-term (6 months). Histopathological examination of AdC68-S immunized mice lungs showed mild histological abnormalities after SARS-CoV-2 infection. Taken together, this study demonstrates the efficacy and durability of the AdC68-S vaccine and constitutes a promising candidate for clinical evaluation.

Viral Hyperparasitism in Bat Ectoparasites: Implications for Pathogen Maintenance and Transmission.

Humans continue to encroach on the habitats of wild animals, potentially bringing different species into contact that would not typically encounter each other under natural circumstances, and forcing them into stressful, suboptimal conditions. Stressors from unsustainable human land use changes are suspected to dramatically exacerbate the probability of zoonotic spillover of pathogens from their natural reservoir hosts to humans, both by increasing viral load (and shedding) and the interface between wildlife with livestock, pets and humans. Given their known role as reservoir hosts, bats continue to be investigated for their possible role as the origins of many viral outbreaks. However, the participation of bat-associated ectoparasites in the spread of potential pathogens requires further work to establish. Here, we conducted a comprehensive review of viruses, viral genes and other viral sequences obtained from bat ectoparasites from studies over the last four decades. This review summarizes research findings of the seven virus families in which these studies have been performed, including Paramyxoviridae, Reoviridae, Flaviviridae, Peribunyaviridae, Nairoviridae, Rhabdoviridae and Filoviridae. We highlight that bat ectoparasites, including dipterans and ticks, are often found to have medically important viruses and may have a role in the maintenance of these pathogens within bat populations.

A New MiRNA MiRm0002 in Eggplant Participates in the Regulation of Defense Responses to Verticillium Wilt.

Verticillium wilt is a major disease that severely affects eggplant production, and a new eggplant miRNA named miRm0002 identified through high-throughput sequencing was highly induced by Verticillium wilt infection. However, the miRm0002 function was still elusive. In this study, the sequence of the miRm0002 precursor was cloned and transgenic eggplants were constructed. In vivo inoculation test and in vitro fungistatic test showed that overexpressing miRm0002 lines were more resistant to Verticillium dahliae and inhibiting miRm0002 lines were more sensitive, compared to the wild-type (WT) control. Some physiological indicators were selected and the results showed that SOD, POD, and CAT activities were significantly increased in Verticillium wilt-infected overexpressing miRm0002 lines, indicating that the expression of miRm0002 activates the antioxidant system. QRT-PCR assay showed that the transcript expression of miRm0002 candidate target ARF8, a gene encoding auxin response factor was negatively related to miRm0002 in WT as well as transgenic eggplants. However, RLM-RACE mapping and degradome sequencing showed miRm0002 could not cleave the sequence of ARF8. Taken together, these data suggest that miRm0002 plays a positive role in the defense response of eggplant against Verticillium wilt.

Genome-wide identification and functional analysis of the WDR protein family in potato.

WD-repeat (WDR) proteins are highly abundant and participate in a seemingly wide range of interactions and cellular functions acting as scaffolding molecules. However, WDR identification in potato has not been conducted so far. In this study, we demonstrated the presence of at least 168 WDR genes in potato (Solanum tuberosum L.) which can be subdivided into five discrete clusters (Cluster I-V) and 10 classes inferred from their phylogenetic features of the constituent genes and the distribution of domains. These genes are distributed on all 12 chromosomes, of which chromosome 3 carries the most genes with 26 StWDRs. The expression of potato WDR genes showed tissue specificity with a high expression in carpels, callus and roots, and the expression patterns were obviously different among different genes. Transcript profiling of 168 StWDR genes revealed the particular tissues in which the 168 StWDR are expressed, and displayed a high expression in carpels, callus and roots. Most StWDRs were modulated by salt, ABA and Verticillium dahliae stresses, of which StWD092 was found to be highly expressed under all the three stresses. These outcomes revealed the intricate crosstalk between WDRs and other regulatory networks in the event of adverse milieu.

High-pressure effects on the molecular aggregation and physicochemical properties of myosin in relation to heat gelation.

Myosin was extracted from the M. psoas muscle of rabbits, and dissolved in 0.6M KCl buffer (pH6.5). Effects of high-pressure (HP, 100 to 300MPa, 9min, 25°C) treatment on myosin solubility, molecular traits (molecular weight and morphology), flow behavior and strength of heat-induced myosin gels were studied and compared with the untreated controls. Myosin subjected to 200MPa HP treatment had lower solubility than samples treated at other pressures (P<0.05). Molecular dimerization and morphological swelling of myosin was observed using gel-permeation chromatography and atomic-force microscopy. Additionally, the shear-thinning behavior of myosin solutions (10mg/mL) was improved by HP treatment (≥200MPa), and a positive trend in gel-strength enhancement was inferred. It is postulated that significant morphological changes in myosin accounted for changes in its functional properties, by the influence of HP treatment on protein-protein and/or protein-water interactions. There is a relationship between molecular morphology and the coalescing behavior of myosin, since significant changes of both attributes were observed at pressures ≥200MPa.