Geometric morphology and population genomics provide insights into the adaptive evolution of Apis cerana in Changbai Mountain.

BACKGROUND: Exploration of adaptive evolution of organisms in response to environmental change can help to understand the evolutionary history of species and the underlying mechanisms of adaptation to local environments, thus guiding future conservation programmes. Before the introduction of Apis mellifera in China, eastern honey bees (Apis cerana) were the only species used for beekeeping in this region. In the mountains of Changbai, populations of A. cerana are considered a distinct ecotype of the species which formed through the distinct selective pressures in this area over time. RESULT: We performed a measure of 300 wing specimens of eastern honey bees and obtained the geometric morphological variation in the wing of A. cerana in Changbai Mountain. A total of 3,859,573 high-quality SNP loci were yielded via the whole-genome resequencing of 130 individuals in 5 geographic regions. CONCLUSION: Corresponding geometric morphology and population genomics confirmed the particularity of the A. cerana in Changbai Mountain. Genetic differentiation at the subspecies level exists between populations in Changbai Mountain and remaining geographic regions, and a significant reduction in the effective population size and an excessive degree of inbreeding may be responsible for a substantial loss of population genetic diversity. Candidate genes potentially associated with cold environmental adaptations in populations under natural selection were identified, which may represent local adaptations in populations. Our study provided insights into the evolutionary history and adaptation of A. cerana in Changbai Mountain, as well as its conservation.

Carbon monoxide releasing molecule 2 exhibits anti-inflammatory effects by regulating T lymphocyte differentiation to protect intestinal barrier in rats with hemorrhagic shock / 中华急诊医学杂志

Objective:To investigate the protective effect of carbon monoxide releasing molecule 2 (CORM-2) on intestinal barrier by regulating the differentiation of T lymphocytes in rats with hemorrhagic shock.Methods:Healthy male Sprague-Dawley rats ( n=56) were randomly (random number) divided into the sham operation group, shock group, dimethyl sulfoxide (DMSO) control group, inactivated carbon monoxide release molecule-2 (iCORM-2) pretreatment group and three pretreatment CORM-2 with the doses of 2, 4 and 6 mg/kg separately. The hemorrhagic shock was induced with the use of a modified Wiggers model. Rats in the CORM-2 group and iCORM-2 group were intraperitoneally injected with CORM-2 with the doses of 2, 4 and 6 mg/kg and 6 mg/kg iCORM-2 instantly before shock induction. Rats in the DMSO group received intraperitoneal administration of 2% DMSO with the same volume of iCORM-2. Rats in the shock group and sham operation group were not pretreated before inducing shock. Mean arterial pressure of each rat was recorded at different phases after catheterization or shock. Twenty-three hours after shock induction, the permeability of intestinal barrier was measured by FITC-dextran flux, and then ileum tissues were harvested to observe histopathologic changes. Immunohistochemistry was used to detect the expression of transcription factors T-bet and Foxp3 of intestinal mucosa in rats, and the expression of interferon-γ (IFN-γ), interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) in intestinal mucosa was measured by Western blot. One-way analysis of variance or Kruskal Wallis rank sum test was used to compare the difference among groups for normal or non-normal distributed data. Results:Compared with the sham operation group, serum concentrations of FITC-dextran were significantly increased in the shock group, DMSO group and iCORM-2 group (all P<0.05). The concentrations of FITC-dextran in serum of three CORM-2 pretreatment groups pretreatment were significantly decreased compared with other groups undergoing shock (all P<0.05). Rats in the shock group, DMSO group and iCORM-2 group showed severe ileum injury. CORM-2 intervention resulted in alleviation of intestinal mucosal injury in rats with shock, and rats in groups pretreatment CORM-2 at the doses of 4 and 6 mg/kg exhibited integrity of anatomic ileac structure. Compared with the sham operation group, T-bet levels of intestinal intraepithelial lymphocytes were increased in shock group and DMSO group (all P<0.05). Compared with the shock group, levels of T-bet were decreased in intestinal epithelium of three groups pretreatment with CORM-2 at the doses of 2, 4 and 6 mg/kg (all P<0.05). Foxp3 levels in intestinal intraepithelial lymphocytes of the iCORM-2 group and two groups pretreatment with CORM-2 at the doses of 4 and 6 mg/kg were increased compared with the shock group and DMSO group (all P<0.05), but there was no significant difference among the shock group, DMSO group and group pretreatment with CORM-2 at 6 mg/kg (all P>0.05). The shock group showed increased expression of IFN-γ (all P<0.05), but unchangeable expression of IL-10 and TGF-β (all P>0.05) compared with the sham operation group. Compared with the shock group, the expression levels of IL-10 in three groups pretreatment with CORM-2 at the doses of 2, 4 and 6 mg/kg were significantly increased (all P<0.05), and the expression levels of TGF-β were increased in two groups pretreatment with CORM-2 at the doses of 4 and 6 mg/kg (all P<0.05). The expression of IFN-γ in group pretreatment with CORM-2 at 6 mg/kg was significantly decreased compared with the shock group ( P<0.05). Conclusions:CORM-2 inhibited the activation of type 1 helper T cells to decrease the expression of proinflammatory factors and upregulated the expression of anti-inflammatory factors. Thus, CORM-2 reduced gut inflammation and protected the intestinal barrier.