Mulberry trees are an important ecological and economic tree species. The latest research by mainland researchers has found that the fusion fracture of chromosomes makes mulberry trees have two sets of chromosome bases. This study shattered the previous perception that "an organism has only one set of chromosome bases" and laid the foundation for accurately mapping the "family tree" of mulberry tree kinship. The relevant research results have been published online by the academic journal Horticultural Research.
"Chromosomes are carriers of genetic material, and the study of chromosomes can provide important references for the analysis of the origin, evolution and kinship of species." Professor He Ningjia, corresponding author of the paper and the State Key Laboratory of Silkworm Genome Biology of Southwest University, introduced that Sichuan mulberry and white mulberry are common varieties of mulberry trees, and previous studies have found that the chromosome bases of the two are 7 and 14 respectively. However, whether the two sets of chromosome bases exist at the same time, and the evolutionary relationship between the two, is unclear.
Through genome sequencing and fluorescence in situ hybridization experiments, the research group of Southwest University found that the 6 chromosomes of Chuansang and the 14 chromosomes of Baisang have high chromosomal colinearity, of which the longest chromosome of Chuansang corresponds to the four chromosomes of Baisang. At the same time, there is a phenomenon of chromosomal fusion in the middle of mitosis and white mulberry to the final stage of meiosis. A large number of studies have shown that the fusion break of chromosomes is the cause of the differentiation of the base number of the two sets of chromosomes, and the research group has proposed the theory of "mulberry chromosome rupture-fusion cycle".
"It's like having two teams with the same number of people, one divided into 14 groups and the other divided into 7 groups." He Ningjia explained that the relationship between these two sets of chromosome cardinals is not a simple multiple relationship, can not replace each other, the two can be through the fusion or rupture of a part of their own chromosomes, mutated into a part of each other.
Xiang Zhonghuai, an academician of the Chinese Academy of Engineering, believes that this research fills the gap in the field of mulberry genetic genome and provides a new thinking path for the study of mulberry germplasm resources and the analysis of the evolutionary mechanism of mulberry plants. (Reporter Ke Gaoyang)
Source: Xinhua News Agency
![#Ice and Snow 2022# The masses watching the competition found that no, Ren Ziwei's skates are just different, not only the color is not the same, the brand is not the same, there is also a story.[fig]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)