Bioscience

A Breakthrough in iPS Research of Pigs

A big progress has been made on the pig cloning with induced pluripotent stem cells (iPS), which is a hard nut to crack in the animal stem cell field through the joint efforts of Dr. Lai Liangxue from the Guangzhou Institute of Biomedicine and Health, CAS, Dr. Xiao Lei from the Zhejiang University and Dr. Du Yutao from the Beijing Genomics Institute. It represents a milestone achievement on the Chinese large animal stem cell research. The paper was published on Cell Research on Dec.18, 2012. A dozen of research groups led by Li Ning, Member of CAS from the Chinese University of Agriculture, were involved in the project. The first iPS cloned piglet was achieved by Dr. Lai Liangxue’s group in 2011 using differentiated iPS cells as donors, followed by the birth of four iPS cloned piglets in the next year by Dr. Du Yutao’s group using treatment of the embryos with histone deacetylase inhibitor. When gene targeted iPS cells are obtained, gene targeted pigs are able to be generated through chimera strategy, followed by breeding or nuclear transfer method. This is the first report in the world that viable piglets can be cloned from iPS cells. The success of the technology paves the way for utilizing iPS cells to generate gene targeted pigs.

The DNA Analysis on a Modern Human 40,000 Years Ago

An international team of researchers including Gao Xing, Fu Qiaomei, Svante Paabo and colleagues from both China and Germany did the DNA analysis from a leg bone found in 2003 at the Tianyuan Cave site located at the southeastern area of Beijing. Most of the work was carried out in a new laboratory jointly run by the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), CAS and the Max Planck Society, Germany. This team successfully extracted nuclear and mitochondrial DNA from this individual. To identify and separate the ancient genetic material from an archaeological find was not an easy matter, as large quantities of DNA from soil bacteria were also present in the sample, the researchers strived hard to apply new techniques and finally realized an important technique breakthrough on it, and enriched the nuclear DNA from the individual with less than 0.03% endogenous DNA. This is the first nuclear DNA sequence of early modern human that has been ever determined. Finally this work was published in the Proceedings of the National Academy of Sciences, USA (PNAS) in January, 2013, titled “DNA analysis of an early modern human from Tianyuan Cave, China”. The main conclusions are early modern humans present in the Beijing area 40,000 year ago were related to the ancestors of many present-day east Asians as well as Native Americans, already diverged from the ancestors of present-day Europeans; The Tianyuan individual did not carry any larger proportion of Neandertal or Denisovan DNA sequences in its genome than present-day people in the region. This research from the aspect of molecular biology found out one member of the direct ancestral Asian population, which is an important research breakthrough.