Molecular characterization and expression of TGFßRI and TGFßRII and its association with litter size in Tibetan sheep.

BACKGROUNDS: Transforming growth factor-ß (TGF-ß) type I receptor (TGFßRI) and type II receptor (TGFßRII) are the members of the TGFß superfamily, which are potent regulators of cell proliferation and differentiation in many organ systems, and they play key roles in multiple aspects of follicle development. OBJECTIVES: We aimed to explore the characterization, expression analysis of TGFßRI and TGFßRII genes, and the association with litter size in Tibetan sheep. METHODS: In this study, we cloned the complete coding sequences of TGFßRI and TGFßRII genes in Tibetan sheep and analyzed their genomic structures. RESULTS: The results showed that percentages of sequences homology of the two proteins in Tibetan sheep were the most similar to Ovis aries (100%), followed by Bos mutus (99%). The RT-qPCR showed that two genes were expressed widely in the different tissues of Tibetan sheep. The TGFßRI expression was the highest in the lung (p < 0.05), followed by the spleen and ovary (p < 0.05). The TGFßRII expression was significantly higher in uterus than that in lung and ovary (p < 0.05). In addition, the χ2 test indicated that all ewes in the population were in Hardy-Weinberg equilibrium, and the population was in medium or low polymorphic information content status. We also found four Single Nucleotide Polymorphism (SNPs), g.9414A > G, g.28881A > G, g.28809T > C, g.10429G > A in sheep TGFßRI gene and g.63940C > T, g.63976C > T, g.64538C > T, g.64504T > A in TGFßRII gene. Three genotypes, except for g.64504T > A, and three haplotypes were identified in each gene. linkage disequilibrium analysis indicated that there was strong linkage disequilibrium in each gene. The association analysis showed that the four SNPs of TGFßRI were associated with litter size (p < 0.05), and g.63940C > T of TGFßRII was confirmed to be associated with litter size (p < 0.05). CONCLUSIONS: Based on these preliminary results, we can assume that TGFß receptors (TGFßRI and TGFßRII) may play an important role in sheep reproduction.

Early-Warning Measures for Ecological Security in the Qinghai Alpine Agricultural Area.

The study area of this paper is the Qinghai alpine agricultural mountain area. An ecological security early-warning model is used to identify the early warning signs of ecosystem destruction, environmental pollution and resource depletion in districts and counties from 2011 to 2018. A combination of qualitative and quantitative early-warning models is used to predict the existence of hidden or sudden advance warnings. The grey (1, 1) model (GM) is used to predict the evolution trend of ecological security warning situations from 2019 to 2021. On this basis, GIS technology is used to analyze the spatial pattern changes in three periods. The results show that from 2011 to 2018, the ecological environment in Qinghai's alpine agricultural mountainous area gradually improved. In 2018, the ecological security early-warning values of all districts and counties were greater than the 2011 values. However, in 2018, the ecological security early-warning levels of PA, LD and HZh (PA, LD and HZh refer to Ledu District, Ping'an District and Huzhu Tu Autonomous County respectively.) were in the "good" ecological early-warning state, while the ecological security levels of other cities were still in the "moderate" or "mild" ecological warning state. According to the prediction results, the early-warning level of ecological security in Qinghai's alpine agricultural mountainous areas will improve further in 2021, with the "good" states dominating. From a spatial perspective, the ecological environment in the northeast region is better than that in the southern region, and the internal differences in the ecological security early-warning levels tend to narrow. Thus, we propose that areas with different ecological security levels should focus on the management and protection of the ecological environment or carry out ecological restoration or reconstruction. The aim of this paper is to provide a reference for the improvement of the ecological environment in general and the sustainable development of the economy and society as well as the ecological environment of alpine agricultural mountainous areas in particular.