Individual and Combined Occurrence of Mycotoxins in Feed Ingredients and Complete Feeds in China.

The objective of this study was to investigate the individual and combined contamination of aflatoxin B1 (AFB1), zearalenone (ZEN) and deoxynivalenol (DON) in feedstuffs from different Provinces of China between 2016 and 2017. A total of 1569 samples, including 742 feed ingredients and 827 complete pig feed samples, were collected from various regions of China for mycotoxins analysis. The results showed that individual occurrence rates of AFB1, ZEN, and DON were more than 83.3%, 88%, and 74.5%, respectively, in all the tested samples. DON was the most prevalent contaminant, followed by ZEN and AFB1, with the average concentrations ranging from 450.0-4381.5 µg/kg, 2.3-729.2 µg/kg, and 1.3-10.0 µg/kg, respectively. Notable, 38.2%, 10.8%, and 0.6% of complete pig feeds were contaminated with DON, ZEN, and AFB1 over China's regulatory limits, respectively. Moreover, over 75.0% analyzed samples were co-contaminated with two or three mycotoxins. In conclusion, the current study revealed that the feedstuffs in China were severely contaminated with DON, followed by ZEN and AFB1 during the past two years. These findings highlight the importance of monitoring mycotoxins in livestock feed and implementing feed management and bioremediation strategies to reduce mycotoxin exposure.

Exploration and implementation for the construction of the quaternary teaching system of medical genetics including teaching, practice, research and clinical application.

Medical genetics, the connection between basic and clinical medicine, is a subject with strong applicability and plays important role in modern medical education system. Based on years of teaching experience and during the construction of state-level top quality course, our teaching team has established the quaternary teaching system of medical genetics which includes teaching, practice, research and clinical application. The four elements of the system interpenetrate, complement and reinforce each other. Specifically, classroom teaching is the basics which is further complemented by social practice, improved by research and promoted by clinical application. The quaternary teaching system provides a feasible way to integrate theoretical and clinical courses. After years of implementation, the teaching system has got great effects on the obvious improvement of research ability, social reputation and clinical service capacities of the research team.

Y chromosome diversity and paternal origin of Chinese cattle.

To determine the Y chromosome genetic diversity and paternal origin of Chinese cattle, 369 bulls from 17 Chinese native cattle breeds and 30 bulls from Holstein and four bulls from Burma were analyzed using a recently discovered USP9Y marker that could distinguish between taurine and indicine cattle more efficiently. In total, the taurine Y1, Y2 haplogroup and indicine Y3 haplogroup were detected in 7 (1.9 %), 193 (52.3 %) and 169 (45.8 %) individuals of 17 Chinese native breeds, respectively, although these frequencies varied amongst the Chinese native cattle breeds examined. Y2 dominates in northern China (91.4 %), while Y3 dominates in southern China (81.2 %). Central China is an admixture zone with Y2 predominating overall (72.0 %). Our results demonstrate that Chinese cattle have two paternal origins, one from B. taurus (Y2) and the other from B. indicus (Y3). The Y1 haplogroup may originate from the imported beef cattle breeds in western countries. The geographical distributions of the Y2 and Y3 haplogroup frequencies reveal a pattern of male indicine introgression from south to north China, and male taurine introgression from north to south China.

Phylogeography and domestication of Chinese swamp buffalo.

To further probe into whether swamp buffaloes were domesticated once or multiple times in China, this survey examined the mitochondrial DNA (mtDNA) Control Region (D-loop) diversity of 471 individuals representing 22 populations of 455 Chinese swamp buffaloes and 16 river buffaloes. Phylogenetic analysis revealed that Chinese swamp buffaloes could be divided into two distinct lineages, A and B, which were defined previously. Of the two lineages, lineage A was predominant across all populations. For predominant lineage A, Southwestern buffalo populations possess the highest genetic diversity among the three hypothesized domestication centers (Southeastern, Central, and Southwestern China), suggesting Southwestern China as the most likely location for the domestication of lineage A. However, a complex pattern of diversity is detected for the lineage B, preventing the unambiguous pinpointing of the exact place of domestication center and suggesting the presence of a long-term, strong gene flow among swamp buffalo populations caused by extensive migrations of buffaloes and frequent human movements along the Yangtze River throughout history. Our current study suggests that Southwestern China is the most likely domestication center for lineage A, and may have been a primary center of swamp buffalo domestication. More archaeological and genetic evidence is needed to show the process of domestication.

[African origin of Chinese domestic donkeys].

Analysis of the 367 mtDNA D-loop sequences (of which 241 sequences were collected from literature) of 399 bp in 13 Chinese domestic donkey breeds revealed 96 different haplotypes with 57 polymorphic sites. The haplotype diversity and the nucleotide diversity were 0.767-0.967 and 0.014-0.032, respectively, indicating abundant genetic diversity in Chinese domestic donkeys. The Neighbor-joining tree of Chinese domestic donkey sequences was constructed with 3 Nubian wild ass sequences, 3 Somali wild ass sequences and 6 Asian wild ass sequences. Our results suggest that the maternal ancestor of Chinese domestic donkeys is highly likely to be Somali and Nubian of African wild ass instead of Asian wild ass.