Effect of MSTN propeptide protein on the growth and development of Altay lamb muscle.

Prokaryotic expression technology was used to express maltose-binding protein binding myostatin (MSTN) propeptide fusion protein. Six disease-free Altay lambs were used in this study. The right leg gastrocnemii were injected with MSTN recombinant propeptide protein. The left leg gastrocnemii (the control group) were injected with the same dose of phosphate based saline. The lambs were fed during four months under the same conditions and then slaughtered. Gastrocnemius samples were hematoxylin-eosin stained and the size of the muscle fibers was measured. A real-time polymerase chain reaction (RT-PCR) showed that single gastrocnemius cells in the experimental group had an average area of 1163.01 µm(2), while it was 845.09 µm(2) in the control group (P < 0.05). This indicates that the MSTN propeptide biological agents had an inhibitory effect on MSTN. In order to reveal its mechanism, RT-PCR was conducted to detect the expression of the differentiation-associated genes MyoD, Myf5, Myogenin, p21, and Smad3. The results showed that, in the MSTN propeptide biological agent injected group, expression levels of MSTN, Smad3, and p21 were lower than the control group, while Myf5, MyoD, and Myogenin were higher compared to the control group. This indicates that, when expression of the MSTN gene was inhibited, muscle cell differentiation and growth can be promoted by Smad3 up-regulated expression of Myf5, MyoD, and Myogenin.

Expression of recombinant myostatin propeptide pPIC9K-Msp plasmid in Pichia pastoris.

Myostatin propeptide can inhibit the biological activity of myostatin protein and promote muscle growth. To express myostatin propeptide in vitro with a higher biological activity, we performed codon optimization on the sheep myostatin propeptide gene sequence, and mutated aspartic acid-76 to alanine based on the codon usage bias of Pichia pastoris and the enhanced biological activity of myostatin propeptide mutant. Modified myostatin propeptide gene was cloned into the pPIC9K plasmid to form the recombinant plasmid pPIC9K-Msp. Recombinant plasmid pPIC9K-Msp was transformed into Pichia pastoris GS115 by electrotransformation. Transformed cells were screened, and methanol was used to induce expression. SDS-PAGE and western blotting were used to verify the successful expression of myostatin propeptide with biological activity in Pichia pastoris, providing the basis for characterization of this protein.

Molecular tracing of white muscardine in Asian corn borer using inter-simple sequence repeat (ISSR) analysis.

Beauveria bassiana is a soil fungus that parasitizes arthropod species, and is used to control the Asian corn borer in Northeast China. In this study, B. bassiana was investigated in Xiaoxian County and Baicheng City, and the results were compared with those of Gongzhuling City, where the fungus was not applied. Using the inter-simple sequence repeat (ISSR) molecular marker technique, 198 isolates were extracted from Asian corn borer and other insect cadavers, and soil and air, and two released strains were analyzed to trace the infection source. In Xiaoxian and Baicheng populations, artificially released B. bassiana subpopulations were more abundant than indigenous fungi, and the released strains were the main cause of disease in those areas. Artificial B. bassiana displayed positive effect on overwintering of Asian corn borers in corn straw stacks in Xiaoxian County. Indigenous populations in Gongzhuling City showed higher genetic variation. In summary, we identified a significant correlation between genetic distance and geographic distance (P < 0.01).

Effect of miR-146a polymorphism on biochemical recurrence risk after radical prostatectomy in southern Chinese population.

Evidence has shown that miR-146a is involved in carcinogenesis and a common G/C variant (rs2910164) in the pre-miR-146a gene has been found to be associated with various cancers. We investigated the potential prognostic role of miR-146a polymorphism in prostate cancer after radical prostatectomy. Seventy-two southern Chinese with prostate cancer undergoing radical prostatectomy were included in this study. miR-146a polymorphism was analyzed by PCR-RFLP. Its prognostic role in biochemical recurrence was assessed using Kaplan-Meier analysis and Cox regression model. We did not find a significant association between miR-146a polymorphism and prostrate-specific antigen failure in the Chinese population [HR (95%CI): 0.83 (0.30-2.32) for CC vs GG/GC]. However, high Gleason score (over 8) was associated with increased biochemical recurrence and poorer PSA-free survival. This study was limited by the length of follow-up. Future studies with longer follow-up would allow evaluation of more direct metrics, such as disease-specific survival, metastasis-free survival, and overall survival.

Evidence for inbreeding depression in the tree Robinia pseudoacacia L. (Fabaceae).

The magnitude of inbreeding depression within populations is important for the evolution and maintenance of mixed mating systems. However, data are sparse on the magnitude of inbreeding depression in Robinia pseudoacacia. In this study, we compared differences in the mature seed set per fruit, seed mass, germination success, and seedling growth between self- and cross-pollination treatments and estimated the inbreeding depression at 3 stages: seed maturation, seedling emergence, and seedling growth at 10 and 20 weeks. We found that progenies resulting from cross-pollination treatments showed significantly higher fitness than progenies resulting from self-pollination, causing high levels of inbreeding depression. Inbreeding depression was not uniformly manifested, however, over the 3 stages. Inbreeding depression was the greatest between fertilization and seed maturation stage (δ = 0.5419), and the seedling emergence (0.3654) stage was second. No significant differences in seedling growth were observed between selfed and crossed progenies. The cumulative inbreeding depression (δ) across all 3 stages averaged 0.7452. Inbreeding depression may promote outcrossing in R. pseudoacacia by acting as a post-pollination barrier to selfing. The large difference in the seed set between self- and cross-pollination that we detected indicated that inbreeding depression would probably be a reasonable explanation for the high abortion and low seed set in R. pseudoacacia.