Study on the genotypes of Echinococcus granulosus in yaks and sheep from Langkazi County in Tibet Autonomous Region of China based on mitochondrial cox1 and nad1.

To determine the genotypes of the epidemic strains of Echinococcus granulosus in livestock in Tibet, samples of E. granulosus cysts were collected from 11 yaks and 62 sheep. Genomic DNA was extracted from these samples, and gene fragments of mitochondrial cytochrome c oxidase subunit I (cox1) and NADH dehydrogenase subunit I (nad1) were amplified by PCR and sequenced. DNASTAR and MAGA7.0 were employed for homology analysis and phylogenetic tree construction. Echinococcus granulosus cysts were detected in 56.2% (41/73) of the samples screened. Of these, 63.4% (26/41) were identified as E. granulosus G1 genotype (common sheep strain), 24.4% (10 /41) as G3 genotype (buffalo strain), and 12.2% (5/41) were G6 genotype (camel strain). The study concludes that yaks and sheep in Langkazi county, Tibet, carry three E. granulosus genotypes (G1, G3, and G6), with the G1 genotype the predominant genotype in the region. This study clarifies the distribution of E. granulosus genotypes, providing genetic data and insight for the surveillance and prevention of echinococcosis.

microRNA-125b Regulates Apoptosis by Targeting Bone Morphogenetic Protein Receptor 1B in Yak Granulosa Cells.

The intronic microRNA, miR-125b, plays a vital role in promyelocytic and hematopoietic stem cells, and in the development and apoptosis of cancer cells. In this study, we showed that miR-125b regulates granulosa cell (GC) apoptosis in the yak ovary. Bioinformatic analyses and luciferase reporter assays demonstrated that bone morphogenetic protein receptor type 1B (BMPR1B) is an miR-125b target. miR-125b overexpression induced apoptosis in yak GC, and affected the mRNA and protein expression of BMPR1B and the ratio of Bcl2/Bax. Silencing of miR-125b decreased the rate of yak GC apoptosis and increased the ratio of Bcl2/Bax. In addition, the effects of an miR-125b inhibitor were overturned by cotransfection with siRNA-BMPR1B2 (siRNA-299) in yak GC. Together, these results demonstrated that miR-125b regulates GC apoptosis in the yak ovary by targeting BMPR1B.

Negative Regulation of Interferon-ß Production by Alternative Splicing of Tumor Necrosis Factor Receptor-Associated Factor 3 in Ducks.

Tumor necrosis factor receptor-associated factor 3 (TRAF3), an intracellular signal transducer, is identified as an important component of Toll-like receptors and RIG-I-like receptors induced type I interferon (IFN) signaling pathways. Previous studies have clarified TRAF3 function in mammals, but little is known about the role of TRAF3 in ducks. Here, we cloned and characterized the full-length duck TRAF3 (duTRAF3) gene and an alternatively spliced isoform of duTRAF3 (duTRAF3-S) lacking the fragment encoding amino acids 217-319, from duck embryo fibroblasts (DEFs). We found that duTRAF3 and duTRAF3-S played different roles in regulating IFN-ß production in DEFs. duTRAF3 through its TRAF domain interacted with duMAVS or duTRIF, leading to the production of IFN-ß. However, duTRAF3-S, containing the TRAF domain, was unable to bind duMAVS or duTRIF due to the intramolecular binding between the N- and C-terminal of duTRAF3-S that blocked the function of its TRAF domain. Further analysis identified that duTRAF3-S competed with duTRAF3 itself for binding to duTRAF3, perturbing duTRAF3 self-association, which impaired the assembly of duTRAF3-duMAVS/duTRIF complex, ultimately resulted in a reduced production of IFN-ß. These findings suggest that duTRAF3 is an important regulator of duck innate immune signaling and reveal a novel mechanism for the negative regulation of IFN-ß production via changing the formation of the homo-oligomerization of wild molecules, implying a novel regulatory role of truncated proteins.