Wuzhishan pig
{{Short description|Chinese breed of pig}}
The Wuzhishan is a Chinese breed of small domestic pig from the Wuzhishan mountains of Hainan Island, off the south coast of China. It was formerly numerous in the island, but in the later twentieth century numbers fell heavily as a consequence of indiscriminate cross-breeding with pigs of faster-growing breeds. It was listed in 1991 as being at risk of extinction, and in 2000 was officially identified as one of nineteen pig breeds most in need of conservation.{{r|cabi|p=714}} Other names for it are the Shan and the Laoshu – which means 'mouse'.{{r|dad}}
History
The Wuzhishan is a traditional breed of the Wuzhishan mountains of Hainan Island, off the south coast of China, and was formerly numerous in the island, with an estimated total population in the 1960s of some {{val|10000}}.{{r|agtr}} Later in the twentieth century, pigs of faster-growing breeds were brought to Hainan from the mainland; indiscriminate cross-breeding with these led to a rapid decline in numbers of the original stock to no more than a few hundreds, and by 1991 it was considered to be at risk of extinction.{{r|cabi|p=714}} In 2000 it was among the nineteen pigs on a government list of breeds with the highest priority for conservation.{{r|cabi|p=714}} A conservation herd at the Institute of Animal Science of the Chinese Academy of Agricultural Sciences in Beijing, established in 1989 from a nucleus of three of the pigs, had by 2004 had grown to some two hundred head.{{r|agtr}} Another herd was established in Hainan by the Academy of Agricultural Sciences in the 1990s, and also grew to about two hundred head.{{r|agtr}}
Characteristics
It is a small pig, with a weight for sows of some {{val|30|–|35|u=kg}}, height at the withers of {{val|35|–|45|u=cm}}, and body length in the range {{val|50|–|70|u=cm}}.{{r|agtr}} The pigs are black with white underparts – the belly, the inner sides of the legs and the feet.{{r|dad}}
The Wuzhishan pig is mainly used to study the human circulatory system due to the similarities between pig and human organs.{{r|agtr}}{{Cite journal |last1=Niu |first1=Miaomiao |last2=Liu |first2=Yaqian |last3=Xiang |first3=Lei |last4=Zhao |first4=Yuqiong |last5=Yuan |first5=Jifang |last6=Jia |first6=Yunxiao |last7=Dai |first7=Xin |last8=Chen |first8=Hua |date=March 2020 |title=Long-term case study of a Wuzhishan miniature pig with diabetes |journal=Animal Models and Experimental Medicine |language=en |volume=3 |issue=1 |pages=22–31 |doi=10.1002/ame2.12098 |issn=2576-2095 |pmc=7167240 |pmid=32318656}}
Genetic research
The full genome sequence and analysis were completed by BGI Group in 2012; the breed was successfully identified in early 2013.{{cite journal |last1=Fang |first1=Xiaodong |display-authors=etal |date=December 2012 |title=The sequence and analysis of a Chinese pig genome |journal=GigaScience |volume=1 |issue=1 |pages=16 |doi=10.1186/2047-217X-1-16 |pmc=3626506 |pmid=23587058 |doi-access=free }} The intellectual property rights for the breed are protected by both ChinesePatent CN1502231A; 201410152868; 201410152864, etc. and American patents.{{Cite web |title=US Patent Issued to Institute of Animal Science Chinese Academy of Agricultural Sciences on May 12 for "Method for Auxiliary Identification of Inbred Line of Wuzhishan Miniature Pig and Its Special Primer" (Chinese Inventors)|publisher=US Fed News Service, Including US State News|date=May 12, 2015 |url=http://www.highbeam.com/doc/1P3-3681566211.html |archive-url=https://web.archive.org/web/20150924204413/http://www.highbeam.com/doc/1P3-3681566211.html |archive-date=2015-09-24}}
On May 18 2015, the Chinese Academy of Agricultural Sciences announced that its Institute of Animal Science agreed to transfer all breeding research to Beijing Grand Life Science & Technology Co., Ltd.,{{cite web |date=2015-05-21 |title=牧医所五指山小型猪近交系成果转让签约仪式在京举行_中国农业科学院 |url=http://www.caas.net.cn/ysxw/gnhz1/256256.shtml |url-status=dead |archive-url=https://web.archive.org/web/20150531013828/http://www.caas.net.cn/ysxw/gnhz1/256256.shtml |archive-date=2015-05-31 |access-date=2015-05-31 |publisher=Caas.net.cn}} which had the sole rights to breed and sell Wuzhishan pigs for commercial purposes.
Multiple Chinese research institutions, medical schools, hospitals, and enterprises conduct research around Wuzhishan pigs to establish their suitability as research models.{{cite journal|journal=Journal of Agricultural Biotechnology|date=2012|page=849~857|doi=10.3969/j.issn.1674-7968.2012.08.001|title=Journal|url= http://www.jabiotech.org/CN/abstract/abstract9796.shtml|access-date=2015-05-31}}{{cite web|url=http://xuewen.cnki.net/CJFD-GWXK200712021.html |title=近交系五指山小型猪消化器官的解剖学研究_CNKI学问 |publisher=Xuewen.cnki.net |access-date=2015-05-31}} Research on future life science and medical applications of the pigs also began to take place, to which the initial results include the injection of embryonic germ cells into blastocysts,{{cite journal |last1=Dong |first1=X |last2=Feng |first2=Shutang |display-authors=etal |date=Mar 2014 |title=Generation of chimeric piglets by injection of embryonic germ cells from inbred Wuzhishan miniature pigs into blastocysts |journal=Xenotransplantation |volume=21 |issue=2 |pages=140–148 |doi=10.1111/xen.12077 |pmid=24329557 |s2cid=21964542}} along with islet isolation and purification.{{cite journal |last1=Jiang |first1=X |last2=Qian |first2=T |last3=Linn |first3=T |last4=Cao |first4=L |last5=Xiang |first5=G |last6=Wang |first6=Y |last7=Peng |first7=H |last8=Xue |first8=P |last9=Zhang |first9=L |last10=Chen |first10=D |last11=Yang |first11=X |date=May 2012 |title=Islet isolation and purification from inbred Wuzhishan miniature pigs |journal=Xenotransplantation |volume=19 |issue=3 |pages=159–165 |doi=10.1111/j.1399-3089.2012.00702.x |pmid=22702467 |s2cid=7099492}}
On June 23, 2017, the Academy of Military Medical Sciences and Grand Life Science declared that the PERV-pol gene-deficient Wuzhishan pig had been identified and verified by systematic virology methods and whole genome sequencing.{{cite web |url=http://www.bio360.net/article/show/42812 |title=我国科学家选育成功世界首例无猪内源性反转录病毒（PERV）传染性的近交系小型猪新品系 – 快讯 基因编辑 生物360 – 中文生命科学界资讯站 |website=www.bio360.net |url-status=dead |archive-url=https://web.archive.org/web/20170907124547/http://www.bio360.net/article/show/42812 |archive-date=2017-09-07}} Grand Life had succeeded in reproducing F0/F1 PERV-noninfectious Wuzhishan pigs that became available for advanced biomedical research purposes.中国实验动物信息网，http://www.lascn.net/Item/28132.aspx This included a series of studies under the 2017-2020 National Primary Research Programs on bio-material development and tissue-organ repair.