An integrative bioinformatics pipeline shows that honeybee-associated microbiomes are driven primarily by pollen composition.

The microbiomes associated with bee nests influence colony health through various mechanisms, although it is not yet clear how honeybee congeners differ in microbiome assembly processes, in particular the degrees to which floral visitations and the environment contribute to different aspects of diversity. We used DNA metabarcoding to sequence bacterial 16S rRNA from honey and stored pollen from nests of 4 honeybee species (Apis cerana, A. dorsata, A. florea, and A. laboriosa) sampled throughout Yunnan, China, a global biodiversity hotspot. We developed a computational pipeline integrating multiple databases for quantifying key facets of diversity, including compositional, taxonomic, phylogenetic, and functional ones. Further, we assessed candidate drivers of observed microbiome dissimilarity, particularly differences in floral visitations, habitat disturbance, and other key environmental variables. Analyses revealed that microbiome alpha diversity was broadly equivalent across the study sites and between bee species, apart from functional diversity which was very low in nests of the reclusive A. laboriosa. Turnover in microbiome composition across Yunnan was driven predominantly by pollen composition. Human disturbance negatively impacted both compositional and phylogenetic alpha diversity of nest microbiomes, but did not correlate with microbial turnover. We herein make progress in understanding microbiome diversity associated with key pollinators in a biodiversity hotspot, and provide a model for the use of a comprehensive informatics framework in assessing pattern and drivers of diversity, which enables the inclusion of explanatory variables both subtly and fundamentally different and enables elucidation of emergent or unexpected drivers.

[Effects of soybean isoflavone on body weight and food utilization rate in ovariectomized rats].

OBJECTIVE: To investigate the inhibitory action of phytoestrogen soybean isoflavone on body weight increasing in ovariectomized rats that imitated postmenopausal women and the effect of decreasing food availability. METHODS: Four-month-old Wistar rats were sham-operated or ovariectomized by abdominal cavity operation and divided into Sham, Ovx, estrogen group(EC) and three isoflavone group and feed 16 weeks. The diet was prepared by ourselves and some contained diethylstilbestrol or different concentration of isoflavone. During the experiment, the rats weight and food intake were recorded. The food utilization rates of each group were calculated. RESULTS: The result showed that high dosage of soybean isoflavone (187.4 mg/kg bw x d) can significantly inhibited OVX induced weight gain and inhibitory action decreased with the dose reduce. Compared with Sham and Ovx group, the food intake of isoflavone group decreased significantly but no different in 3 dosage group and higher than EC group. Compared with Ovx group, the food utilization rates of high isoflavone group decreased significantly but higher than EC group. Isoflavone not influenced the growth and organ/body rates of rats. CONCLUSION: High dosage of isoflavone (187.4mg/kg bw x d) decreased OVX rat's weight gain significantly through reducing food utilization rate.