There are only six isolated living giant panda populations, and a comprehensive understanding their genetic health status is crucial for the conservation of this vulnerable species. Liangshan Mountains is one of the main distribution areas of living giant pandas and is outside the newly established Giant panda national Park. In this study, 971 giant panda fecal samples were collected in the heartland of Liangshan Mountains (Mabian Dafengding Nature Reserve: MB; Meigu Dafengding Nature Reserve: MG; and Heizhugou Nature Reserve: HZG). Microsatellite makers and mitochondrial D-loop sequences were used to estimate population size and genetic diversity. We identified 92 individuals (MB: 27, MG: 22, HZG: 43) from the three reserves. Our results showed that: 1) Genetic diversity of three giant panda populations was medium-low; 2) Quite a few loci deviated significantly from the Hardy-Weinberg equilibrium and almost all these deviated loci showed significant heterozygote deficiencies and inbreeding; 3) Three giant panda populations have substantial genetic differentiation with the most differentiation between MB and the two other populations; 4) a large amount of giant panda feces outside the three reserves were found, implying the existence of protection gap. These results indicated that the giant panda population in Liangshan Mountains is at an risk of genetic decline or extinction given stochastic events and urgent need of human management. This study revealed that high attention should be paid to the protection of these giant panda populations outside the Giant panda national Park, to ensure them survival in their distribution areas.

Spodoptera litura is an important polyphagous pest that causes great damage to agriculture. We performed RNA-seq from 15 individuals of S. litura, including different larval (fifth and sixth instar larvae), chrysalis, and adult developmental stages. We also sequenced the Spodoptera frugiperda to compared with the S. litura. A total of 101,885 differentially expressed transcripts (DETs) were identified in the S. litura. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that the S. litura may undergo active development and basic metabolism, such as xenobiotic and detoxifying metabolism, during its larvae and adult stages, which explains the difficulty to control it. We also found that DETs of single-copy orthologous genes between S. litura and S. frugiperda were involved in basic metabolism and developmental, but S. litura were highly enriched in energy and metabolic processes, whereas S. frugiperda had stronger nervous and olfactory functions. Metagenomics analysis in larval S. litura and S. frugiperda revealed that microbiota can both participate in the detoxification and metabolism processes in them, but the relative abundance of detoxification-related microbiota was more abundant in S. frugiperda. Transcriptome results also confirmed the detoxification-related pathway of S. frugiperda was more abundant than that of S. litura. Therefore, we can conclude that the detoxification ability of S. frugiperda is stronger than that of in S. litura, which is related to the wide adaptation and strong resistance of S. frugiperda. Our study might provide clues to the development of novel pest control strategies.

The gut microbiomes of the host are large and complex communities, which helps to maintain homeostasis, improves digestive efficiency, and promotes the development of the immune system. The small mammals distributed in Sichuan Province are the most popular species for biodiversity research in Southwest China. However, the effects of different diets on the structure and function of the gut microbial community of these small mammals are poorly understood. In this study, whole-metagenome shotgun sequencing has been used to analyze the composition and functional structures of the gut microbiota of seven small mammals in Laojunshan National Nature Reserve, Sichuan Province, China. Taxonomic classification revealed that the most abundant phyla in the gut of seven small mammals were Bacteroides, Proteobacteria and Firmicutes. Moreover, Hafnia, Raoultella and Aeromonas were most abundant genus in the gut microbiomes of these seven species. At the functional level, we annotated a series of KEGG functional pathways, six Cazy categories and 46,163 AROs in the gut microbiomes of the seven species. Comparative analysis found that the difference in the gut microbiomes between the Soricidea and Muridae concentrated on the increase in the F/B (Firmicutes/Bacteroides) ratio in the Soricidea group, probably driven by the high fat and calorie digestive requirements due to their insectivorous diet. The comparative functional profiling revealed that functions related to metabolism and carbohydrates were significantly more abundant in Muridae group, which may be attributed to their high carbohydrate digestion requirements caused by their herbivorous diet. These data suggested that different diets in the host may play an important role in shaping the gut microbiota, and lay the foundation for teasing apart the influences of heritable and environmental factors on the evolution of gut microbial communities.