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Species conservation can be improved by knowledge of genetic diversity and demographic history. The Sichuan hill-partridge (Arborophila rufipectus , SP) is an endangered species endemic to the mountains in southwestern China. However, little is known about this species' genomic variation and demographic history. Here, we present a comprehensive whole-genome analysis of six SP individuals from the Laojunshan National Nature Reserve in Sichuan Province, China. We observe a relatively high genetic diversity and low level of recent inbreeding in the studied SP individuals. This suggests that the current population carries genetic variability that may benefit the long-term survival of this species, and that the present population may be larger than currently recognized. Analyses of demographic history showed that fluctuations in the effective population size of SP are inconsistent with changes of the historical climate. Strikingly, evidence from demographic modeling suggests SPs population decreased dramatically 15,100 years ago after the Last Glacial Maximum, possibly due to refugial isolation and later human interference. These results provide the first detailed and comprehensive genomic insights into genetic diversity, genomic inbreeding levels, and demographic history of the Sichuan hill-partridge, which are crucial for the conservation and management of this endangered species. [ABSTRACT FROM AUTHOR]

Blister beetles (Coleoptera: Meloidae) produce a natural defensive toxin cantharidin (CTD), which has been used for various cancer treatments and other diseases. Currently, the lack of chromosome‐level reference genomes in Meloidae limits further understanding of the mechanism of CTD biosynthesis and environmental adaptation. In this study, the chromosome‐level genome assembly of Mylabris phalerata was generated based on PacBio and Hi‐C sequencing. This reference genome was about 136.68 Mb in size with contig N50 of 9.17 Mb and composed of 12 chromosomes. In comparison to six other Coleoptera insects, M. phalerata exhibited multiple expanded gene families enriched in juvenile hormone (JH) biosynthetic process pathway, farnesol dehydrogenase activity, and cytochrome P450, which may be related to CTD biosynthesis. Consistently, the transcriptomic analysis suggested the "terpenoid backbone biosynthesis" pathway and "the juvenile hormone" as putative core pathways of CTD biosynthesis and presented eight up‐regulated differential expression genes in male adults as candidate genes. It is possible that the restricted feeding niche and lifestyle of M. phalerata were the cause of the gene family's contraction of odorant binding proteins. The ABC transporters (ABCs) related to exporting bound toxins out of the cell and the resistance to the self‐secreted toxins (e.g. CTD) were also contracted, possibly due to other self‐protection strategies in M. phalerata. A foundation of understanding CTD biosynthesis and environmental adaptation of blister beetles will be established by our reference genome and discoveries. [ABSTRACT FROM AUTHOR]

The red panda (Ailurus fulgens) is a distinctive mammal known for its reliance on a diet primarily consisting of bamboo. The gut microbiota and overall health of animals are strongly influenced by diets and environments. Therefore, conducting research to explore the taxonomical and functional variances within the gut microbiota of red pandas exposed to various dietary and environmental conditions could shed light on the dynamic complexities of their microbial communities. In this study, normal fecal samples were obtained from red pandas residing in captive and semi‐free environments under different dietary regimes and used for metabolomic, 16S rRNA, and metagenomic sequencing analysis, with the pandas classified into four distinct cohorts according to diet and environment. In addition, metagenomic sequencing was conducted on mucus fecal samples to elucidate potential etiological agents of disease. Results revealed an increased risk of gastrointestinal diseases in red pandas consuming bamboo shoots due to the heightened presence of pathogenic bacteria, although an increased presence of microbiota‐derived tryptophan metabolites appeared to facilitate intestinal balance. The red pandas fed bamboo leaves also exhibited a decrease in gut microbial diversity, which may be attributed to the antibacterial flavonoids and lower protein levels in leaves. Notably, red pandas residing in semi‐free environments demonstrated an enriched gut microbial diversity. Moreover, the occurrence of mucus secretion may be due to an increased presence of species associated with diarrhea and a reduced level of microbiota‐derived tryptophan metabolites. In summary, our findings substantiate the influential role of diet and environment in modulating the gut microbiota of red pandas, offering potential implications for improved captive breeding practices. [ABSTRACT FROM AUTHOR]

Simple Summary: Red pandas have evolved to become specialized bamboo eaters within Carnivora. Probably due to the difficulty in obtaining materials, reports on genes related to digestion and metabolism at expression and regulation levels in red pandas are rare. Red pandas and carnivorous mammal ferrets have a close phylogenetic relationship. They both consume highly nutritious milk during the suckling period, but consume low-energy bamboo and high-energy meat during the adult period, respectively. In order to explore the molecular mechanisms of dietary changes and nutrient utilization in red pandas, we discussed (1) the differences in expression changes of some genes related to digestion and metabolism in the stomach of these two species after food changes, as well as the expression adaptation of genes related to digestion and metabolism in both species during different feeding periods, and (2) the regulatory effects of lncRNAs and miRNAs on adaptive expressions of genes related to digestion and metabolism in both species from suckling to adult. Red pandas evolved from carnivores to herbivores and are unique within Carnivora. Red pandas and carnivorous mammals consume milk during the suckling period, while they consume bamboo and meat during the adult period, respectively. Red pandas and carnivorous mammal ferrets have a close phylogenetic relationship. To further investigate the molecular mechanisms of dietary changes and nutrient utilization in red pandas from suckling to adult, comparative analysis of the whole transcriptome was performed on stomach tissues from red pandas and ferrets during the suckling and adult periods. The main results are as follows: (1) we identified ncRNAs for the first time in stomach tissues of both species, and found significant expression changes of 109 lncRNAs and 106 miRNAs in red pandas and 756 lncRNAs and 109 miRNAs in ferrets between the two periods; (2) up-regulated genes related to amino acid transport regulated by lncRNA-miRNA-mRNA networks may efficiently utilize limited bamboo amino acids in adult red pandas, while up-regulated genes related to amino acid degradation regulated by lncRNAs may maintain the balance of amino acid metabolism due to larger daily intakes in adult ferrets; and (3) some up-regulated genes related to lipid digestion may contribute to the utilization of rich nutrients in milk for the rapid growth and development of suckling red pandas, while up-regulated genes associated with linoleic acid metabolism regulated by lncRNA-miRNA-mRNA networks may promote cholesterol decomposition to reduce health risks for carnivorous adult ferrets. Collectively, our study offers evidence of gene expression adaptation and ncRNA regulation in response to specific dietary changes and nutrient utilization in red pandas during suckling and adult periods. [ABSTRACT FROM AUTHOR]

Macaques (genus Macaca) are the most widely distributed non‐human primates, and their evolutionary history, gene expression profiles, and genetic differences have been extensively studied. However, the DNA methylomes of macaque species are not available in public databases, which hampers understanding of epigenetic differences among macaque species. Epigenetic modifications can potentially affect development, physiology, behavior, and evolution. Here, we investigated the methylation patterns of the Tibetan macaque (M. thibetana; TM), Chinese rhesus macaque (M. mulatta lasiota; CR), and crab‐eating macaque (M. fascicularis; CE) through whole‐genome bisulfite sequencing from peripheral blood. We compared genome‐wide methylation site information for the three species. We identified 12,128 (CR vs. CE), 59,165 (CR vs. TM), and 39,751 (CE vs. TM) differentially methylated regions (DMRs) in the three macaques. Furthermore, we obtained the differentially expressed genes (DEGs) among the three macaque species. The differences between CR and CE were smaller at both the methylome and transcriptome levels than compared with TM (CR vs. TM and CE vs. TM). We also found a change in the density of single nucleotide mutations in DMRs relative to their flanking regions, indicating a potential mechanism through which genomic alterations may modulate methylation landscapes, thereby influencing the transcriptome. Functional enrichment analyses showed the DMR‐related genes were enriched in developmental processes and neurological functions, such as the growth hormone‐related pathway, insulin secretion pathway, thyroid hormone synthesis pathway, morphine addiction, and GABAergic synapses. These differences may be associated with variations in physiology and habitat among the macaques. Our study provides one of the first genome‐wide comparisons of genetic, gene expression, and epigenetic variations across different macaques. Our results should facilitate further research on comparative genomic and genetic differences in macaque species. [ABSTRACT FROM AUTHOR]