Heavy metal residues in natural ecosystems have emerged as a significant global environmental problem requiring urgent resolution. Because these elements are non-biodegradable, organisms can accumulate excessive levels of heavy metal elements into their tissues. Previous studies suggest that prolonged exposure to heavy metal enrichment poses comprehensive toxicity to various organs in vertebrates. However, few studies have focused on elucidating the molecular mechanism underlying the hepatotoxic effects of heavy metal enrichment in Chiroptera. In this study, 10 Hipposideros armiger individuals were dissected from Yingde City (YD, relatively pollution-free) and Chunwan City (CW, excessive heavy metals emission). Environmental samples were also obtained. To investigate the mechanism of heavy metal toxicity in bat livers, we employed a combination of multi-omics, pathology, and molecular biology methods. Our results revealed significant enrichment of Cd and Pb in the bat livers and food sources in the CW group (P<0.05). Furthermore, prolonged accumulation of heavy metals disrupted hepatic transcription profiles associated with the solute carriers family, the ribosome pathway, ATP usage, and heat shock proteins. Excessive heavy metal enrichment also altered the relative abundance of typical gut microbe taxa significantly (P<0.05), inhibiting tight-junction protein expression. We observed a significant decrease in the levels of superoxide dismutase, glutathione peroxidase, and glutathione (P<0.05), along with elevated reactive oxygen species (ROS) density and malondialdehyde content following excessive heavy metal enrichment. Additionally, hepatic fat accumulation and inflammation injuries were present under conditions of excessive heavy metal enrichment, while the contents of metabolism biomarkers significantly decreased (P<0.05). Consequently, prolonged heavy metal enrichment can induce hepatotoxicity by disturbing the microbes-gut-liver axis and hepatic transcription modes, leading to a decrease in overall metabolic activity in bats. Our study offers strategies for biodiversity conservation and highlights the importance of addressing environmental pollution to raise public awareness.

We describe a new species (Sinospelaeobdella jiangxiensissp. n.) from a natural cave in southwestern Jiangxi Province, China, according to external and internal morphology and COI gene sequences. S. jiangxiensissp. n. is distinguishable from other species of Sinospelaeobdella primarily by morphological characteristics, including body length, the position of the fifth pair of eyes and the first pair of testes, the number of caeca, and the shape and number of auricular projections. We also estimate its phylogenetic position within the genus Sinospelaeobdella. Molecular phylogenetic analyses supported the morphological delimitation of S. jiangxiensissp. n. as separate from S. wulingensis. Both the morphological and molecular data support S. jiangxiensissp. n. as a new species, so the results provide critical data for the determination and conservation of Sinospelaeobdella, and enhance the documented diversity of this recently established genus.

Since the emergence of Severe Acute Respiratory Syndrome (SARS) in 2002, bats have been recognized as important reservoirs of diverse coronaviruses (CoVs). Despite extensive research on the broad geographic transmission of bat CoVs, there is a notable gap in understanding the transmission dynamics within sympatric bat communities. Using a phylogeographic Bayesian statistical framework, we examined CoV transmission patterns and their determinants in a region where four bat roosting caves coexist and CoVs circulate persistently. Our findings reveal that two subgenera of CoVs, α-CoVs and β-CoVs dominate different bat caves at varying times. Notably, β-CoVs show more frequent cross-species transmission events among the dominant reservoir hosts, bats of Rhinolophidae. Phylogenetic distance between host species emerges as the key influence factor of viral cross-species transmission, whereas cohabitation duration and the number of hosts sharing caves do not significantly influence viral transmission. In addition, we emphasize that the compositional similarity of species in the roosting caves is critical for the inter-cave transmission of bat-CoVs, rather than the distance between cave. These results provide novel insights into the complex transmission dynamics of bat CoVs within sympatric bat communities.

Bats are reservoirs for many emerging viruses, yet broad-scale spatial patterns of bat viromes and their ecological determinants remain unclear, limiting spillover risk assessment. To address this, we conducted a standardized survey across central to southern China. During 2022–2023, fecal samples were collected from 527 bats representing 17 species at 21 caves in seven provinces. Using each cave as the analytical unit, samples from all species at a site were pooled to construct 21 fecal RNA virome libraries for metatranscriptomic sequencing; viral-like contigs were annotated, and viral alpha/beta diversity was quantified at the genus level. Sites were grouped by geographic distance and latitude to evaluate spatial differentiation and to relate virome patterns to host community attributes and environmental factors. We annotated 56 viral families, including 19 vertebrate-associated families, with multiple families and genera shared across geographic groupings. Vertebrate-associated viral diversity showed limited evidence of geographic isolation within the study region but suggested gradual turnover with latitude. Host species richness was the strongest correlate of virome diversity, exceeding the effects of evaluated environmental variables (e.g., climate and human activity). These results support prioritization of species-rich bat habitats for surveillance and risk assessment.

Bats, as the world’s second-largest mammalian order, have garnered significant attention for their ability to harbor numerous viruses without exhibiting disease symptoms. Nucleotide-binding domain and leucine-rich repeat-containing receptors (NLRs) are crucial components of the immune system. This study conducted an evolutionary analysis of the NLR gene family across 26 bat species to investigate the molecular mechanisms underlying their role in viral resistance under high viral load pressure. We identified gene duplication events in multiple genes. The NLR gene family exhibited high conservation throughout evolution, which may contribute to the occurrence of gene duplication. This conserved genomic structure also ensures functional stability, safeguarding bats’ antiviral resistance. Most NLR genes primarily function within the type I interferon (IFN) signaling pathway and the NF-κB signaling pathway. The NLR gene family enhances the innate immune capacity of bats through the adaptive evolution of some genes, combining enhanced gene functionality with the maintenance of gene conservation at a low evolutionary rate. Moreover, bats employ diverse innate immune strategies, where multiple immune pathways collectively establish the innate immune barrier. The molecular evolution of this gene family provides new insights into the molecular mechanisms and functional pathways involved in the innate immune response of bats.