DNA metabarcoding uncovers the diet of subterranean rodents in China

Geographical Variation of Diet Composition of Cervus nippon kopschi in Jiangxi, China Based on DNA Metabarcoding

Food resources are the fundamental basis for the survival and reproduction of animals. Diet research is the foundation for understanding their ecological habits and is of great significance for evaluating their survival status and carrying out effective protection and management. South China sika deer (Cervus nippon kopschi) is the most endangered subspecies of wild sika deer in China, with a small population and a shrinking distribution area. Here, we used DNA metabarcoding technology to study the diet composition of C. n. kopschi in Taohongling Sika Deer National Nature Reserve in Jiangxi, China. Comparative analysis of diet composition among different areas (A-E) of C. n. kopschi was conducted, as well as C. n. hortulorum raised in the same areas. We found that the dominant families in the diet composition of C. n. kopschi were Rosaceae (46.73% of relative abundance), Anacardiaceae (6.02%), Poaceae (5.54%), and Fabaceae (3.92%), with Rubus (45.43%) being the absolute dominant genus. Thirty-two preferred plant species were identified in the diet of C. n. kopschi. The highest relative abundance (45%) was Rubus reflexus. The dominant family and genus in the diet composition of C. n. hortulorum were Fabaceae (33.89%) and Pueraria (32.87%), respectively. Of the 15 preferred plant species, the highest relative abundance was Pueraria montana (33%). The richness, diversity, and evenness of diet composition in Area B of C. n. kopschi were the highest among all areas, with significant differences compared to Areas C, D, and E. Diet composition of deer in Area A did not differ significantly from those in other areas. Principal coordinate analysis (PCoA) and nonmetric multidimensional scaling (NMDS) both indicated a significant separation in the diet composition of C. n. kopschi and C. n. hortulorum, while Area B showed significant separation from the other areas. This study elaborates on the diet composition information of C. n. kopschi and can provide a reference for the protection and improvement of the habitat of sika deer.

The associations of maternal and children's gut microbiota with the development of atopic dermatitis for children aged 2 years

BACKGROUND

It is critical to investigate the underlying pathophysiological mechanisms in the development of atopic dermatitis. The microbiota hypothesis suggested that the development of allergic diseases may be attributed to the gut microbiota of mother-offspring pairs. The purpose of this study was to investigate the relationship among maternal-offspring gut microbiota and the subsequent development of atopic dermatitis in infants and toddlers at 2 years old.

METHODS

A total of 36 maternal-offspring pairs were enrolled and followed up to 2 years postpartum in central China. Demographic information and stool samples were collected perinatally from pregnant mothers and again postpartum from their respective offspring at the following time intervals: time of birth, 6 months, 1 year and 2 years. Stool samples were sequenced with the 16S Illumina MiSeq platform. Logistic regression analysis was used to explore the differences in gut microbiota between the atopic dermatitis group and control group.

RESULTS

Our results showed that mothers of infants and toddlers with atopic dermatitis had higher abundance of Candidatus_Stoquefichus and Pseudomonas in pregnancy and that infants and toddlers with atopic dermatitis had higher abundance of Eubacterium_xylanophilum_group at birth, Ruminococcus_gauvreauii_group at 1 year and UCG-002 at 2 years, and lower abundance of Gemella and Veillonella at 2 years. Additionally, the results demonstrated a lower abundance of Prevotella in mothers of infants and toddlers with atopic dermatitis compared to mothers of the control group, although no statistical difference was found in the subsequent analysis.

CONCLUSION

The results of this study support that gut microbiota status among mother-offspring pairs appears to be associated with the pathophysiological development of pediatric atopic dermatitis.

Increased availability of preferred food and decreased foraging costs from degraded grasslands lead to rodent pests in the Qinghai-Tibet Plateau

The increased population density of rodent species during ongoing grassland degradation further deteriorates its conditions. Understanding the effects of grassland degradation on rodent feeding habits is of great value for optimizing grassland management strategies. In this study, lightly degraded (LD), moderately degraded (MD), severely degraded (SD), and reseeded grassland (RG) were selected and their plant resources and soil physical properties were investigated. In addition, the study used ITS2 barcode combined with the Illumina MiSeq sequencing method to analyze the food composition and proportion of plateau zokors in different grassland conditions. The results showed that, with grassland degradation, plant biomass decreased, but the relative proportion of forbs increased (LD: 32.05 ± 3.89%; MD: 28.97 ± 2.78%; SD: 49.16 ± 4.67% and RG: 10.93 ± 1.53%). Forbs were the main food of the plateau zokor, accounting for more than 90% of their diet, and the animal had a clear preference for Potentilla species; the soil compaction of feeding habits showed a decreasing trend in the 10–25 cm soil layer, suggesting a decreased foraging cost. Nutritional analysis showed that the stomach content of crude protein in zokors feeding on MD grassland was significantly higher than that of animals feeding on the other grassland types. Structural equation modeling showed that soil physical properties and the relative biomass of forbs had significant (P < 0.05) and extremely significant (P < 0.001) impacts on the population density of plateau zokors, with direct impact contribution rates of 0.20 and 0.63. As the severity of grassland degradation increased, although the aboveground and underground biomass of the plants decreased, the proportion of food preferred by the plateau zokor increased, and the corresponding changes in the feeding environment resulted in decreased foraging energy expenditure, thereby increasing the suitability of the degraded grassland for the plateau zokor. Compared with degraded grassland, the food diversity and evenness of zokors increased, the food niche width enlarged, and the proportion of weeds decreased in RG, which increased the difficulty of obtaining food. Reseeding in grassland management is therefore an effective way to control plateau zokors.