北京动物园

Hypoderma diana Brauer, 1858, poses a significant threat to species of deer, yet records of this species in China remain fragmented and lack comprehensive documentation. Following high mortality in wapiti populations in Inner Mongolia during 2023-2024, surveys were conducted in the Gaogesitai Hanwula Nature Reserve in March 2025. Species identity was established through rigorous morphological analysis of third-instar larvae and an emerged adult female using light and scanning electron microscopy, supplemented by a 689 bp COI fragment. Results confirmed H. diana as the causative agent, with larvae localized along the host's vertebral column. Comparative SEM analysis of the antennomaxillary sensory complex in H. diana, H. bovis (Linnaeus, 1758), and H. lineatum (Villers, 1789) revealed undifferentiated, volcano-like warts, contrasting sharply with the highly differentiated antennae and sensilla of Oestrus ovis Linnaeus, 1758. This study represents an inaugural record of H. diana in the Chifeng region and provides the first atlas of diagnostic features for both third-instar larvae and adults. These findings document H. diana as a critical agent of myiasis in the Manchurian wapiti, refining its known epidemiological profile in China and establishing an essential morphological reference for future wildlife health surveillance.

Diving behavior in waterfowl represents a remarkable physiological adaptation requiring extensive genetic modifications to cope with hypoxic and high-pressure underwater environments. We analyzed 25 Anseriformes genomes, representing diverse foraging strategies, and identified 13,873 orthogroups with 7991 single-copy orthogroups across all species. Comparative genomic analysis revealed significant positive selection signatures in diving waterfowl, with GO and KEGG enrichment analyses highlighting key functional adaptations in metabolic regulation, transmembrane and immune responses. Metabolic pathways showed enrichment in insulin secretion and peptide hormone regulation, while transport mechanisms dominated molecular functions, including ion channels and solute transporters essential for maintaining cellular homeostasis under hypoxic conditions. Neural adaptations were evident through enrichment of postsynaptic density components and neurotransmitter transport systems. We identified nine genes with shared amino acid substitutions across diving species, including critical genes PLB1, PKD1, and GPR34. These findings demonstrate convergent molecular evolution in diving waterfowl, revealing the genetic basis underlying successful aquatic foraging strategies.

ABSTRACT Type I interferons (IFNs) play essential roles in antiviral immune responses. The extensive diversification of type I IFNs into various subtypes and duplicated gene copies has posed significant challenges for evolutionary reconstruction. To address this, we developed the type I IFN sequence composition and structure (IFN‐SCOPE) model and gene‐network graph degree centrality (GENE‐GRADE) algorithm, which transform the discovery of type I IFN evolutionary trajectories into computing the node centrality in its gene networks. Through synteny‐guided analysis, we verified that three previously reported evolutionarily conserved type I IFN loci (HACD4, MOB3B, and UBAP2) have maintained chromosomal colocalization across all major amniote lineages. While the MOB3B locus maintained a single IFN‐κ ortholog, the HACD4 (IFN‐HA) and UBAP2 (IFN‐UB) loci showed lineage‐specific expansion patterns: IFN‐HA proliferated in mammals/reptiles but remained single‐copy in birds, whereas IFN‐UB expanded in birds but not in other lineages. A phylogenetic analysis revealed that these independently evolved multicopy genes nevertheless clustered into two conserved subgroups (IFN‐HA2/HA1 and IFN‐UB2/UB1), suggesting convergent functional specialization. Within the IFN‐HA and IFN‐UB clusters, the single‐copy IFN‐HA2 and IFN‐UB2 genes, positioned at the ancestral ends of their respective genomic arrays, likely represent the progenitor sequences of each locus, where the poorly characterized IFN‐ν (rather than IFN‐β) is the ancestral form of mammalian IFN‐HA subtypes. Furthermore, wet lab evidence revealed type I IFN genes at noncanonical loci resulting from interchromosomal duplication events in tortoises and diving ducks and provided clear evidence that interchromosomal duplications contributed to type I IFN gene diversity. These discoveries advance our understanding of the evolutionary mechanisms that shape type I IFN genes in amniotes and are potentially beneficial for the development of novel type I IFN‐based antiviral treatments through comparative immunological approaches.

In zoo husbandry and wildlife conservation, accurate sex identification is critical for American mammals with indistinct sexual dimorphism, yet relevant molecular studies are limited. In this study, the Y-chromosomal SRY gene, a core male sex-determining factor in mammals, was investigated. Primers were designed for its conserved regions, and PCR amplification, sequencing, and bioinformatic analysis were conducted on seven Neotropical mammals (e.g., two-toed sloth, jaguar). Their SRY nucleotide sequence similarity reached 83.2-95.0%. Over 60 American mammals from Carnivora, Xenarthra, Primates, Artiodactyla and Rodentia were further analyzed via GenBank data: a phylogenetic tree was built, primer binding sites were predicted, and the target fragment was found to have purifying selection (dN/dS = 0.352) and span three HMG-box motifs. This study provides a potential cross-species sex identification method for American mammals, offering molecular support for precise zoo management and wild conservation, with important practical and scientific value.

The gut microbiota of avian species is influenced by a diverse array of factors, encompassing host genetics, environmental conditions, physiological states, dietary patterns and age, among others. With the advent of high-throughput sequencing technology, research into avian gut microbiota has gained momentum. The artificial lake within the zoo serves as a unique nexus between the natural and captive environments. Despite this, our understanding of the gut microbiota of waterbirds residing in such an artificial habitats remains limited. In this study, we focused on three distinct species of waterbird kept in the artificial lake and traditional enclosures. We used high-throughput sequencing technology to determine the faecal microbiome of 25 waterbirds from three species, including bar-headed goose (Anser indicus), ruddy shelduck (Tadorna ferruginea) and black-necked crane (Grus nigricollis). Our objective was to elucidate the composition and community structure of their gut microbiota, while exploring the nexus between dietary habits and gut microbiota. Our findings revealed that the dietary patterns and gut microbiota of ruddy shelducks and bar-headed geese exhibited similar traits. On the other hand, black-necked cranes, whose food primarily consists of fish and meat, possessed a gut microbiota optimized for the digestion of protein and fat. Notably, artificial lakes may support higher microbial diversity compared to cage feeding. The results underscore the significance of diet as the primary determinant of gut microbiota variation among the captive waterbird. This study provides implications for promoting the healthy growth and well-being of wild waterbird in captivity.