Medical Sciences

Negate Ohno Hypothesis about Sex Chromosomes Evolution, Subvert Cornerstone of Sex Chromosomes Evolution Theory

The appearance of sex is an important event in the organic evolution. Since the gender of mammal is dependent on sex chromosomes, the issue about the origin and evolution about sex chromosomes catches biologists’ great attention for a long time. Based on the analysis of RNA-Seq data of second gene sequencing technology, the research group led by Professor He Xionglei belonging to School of Life Science, Sun Yat-Sen University, found out that the general amount of a single X chromosome is about half of the general amount of two autosomes, different from the previous study considering the general amount of a single X chromosome is almost the same as the general amount of two autosomes. The finding of Professor He Xionglei’s research group negates Ohno Hypothesis about sex chromosomes evolution, and raises a new question about the amount compensation of set chromosomes.

This important finding was published in World-top Periodical Nature Genetics (34.284 in Factor of Influence, Science – Genetics), and later it was published in other well-known periodicals, such as Nature Reviews Genetics. The first completed institution of the paper is Sun Yat-Sen University; the co-first authors are Xiong Yuanyan, a Ph.D candidate of Information Biology of School of Life Science, and Chen Xiaoshu, a Ph.D candidate of Biochemistry and Molecular Biology of School of Life Science and Professor Zhang Zhijian of University of Michigan, USA is the major cooperator.

In 2007, 30-year old Mr. He Xionglei graduated from University of Michigan with his Ph.D and was recruited as a professor by Sun Yat-Sen University through Hundred Talents Program. During the period working in Sun Yat-Sen University, Professor He Xionglei devotes himself to the research of sex chromosomes and his findings overthrow the previous theoretical framework of X chromosome evolution, opening a new chapter of research on sex chromosomes evolution. Meanwhile, this is the first study that negates the result of major biology based on gene chip technology by using the data of RNA-Seq technology. Considering the usage of gene chip technology in various fields in the past decades, this finding means there is possibility that this traditional gene chip technology would be wavered, which is a important caution in the whole field.

Recently, School of Life Science continuously enhances the construction of branches of learning, emphasises the importance of talents, highly values the combination of introducing and cultivating talents, establishes high level creation teams and talents cultivating base, providing first-class research and teaching service platform for young teachers. The research finding of Professor He Xionglei is the marked achievement of Life Science School for constructing a leading at home and well-known abroad life science school.