Chinese scientists create single-chromosome yeast

Chinese scientists have created a single-chromosome yeast and its life functions show no difference from its wild counterparts, making it the first time in the world that organisms with multiple chromosomes were artificially transformed into single-chromosome form.

The genomes of eukaryote organisms are divided into chromosomes, DNA molecules carrying genetic information of an organism, and the number of chromosomes varies across species. For example, humans have 23 chromosome pairs while mice have 20 and fruit flies have four.

Yeast naturally contains 16 linear chromosomes, and a group of scientists at the Shanghai-based Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences / Institute of Plant Physiology and Ecology under CAS created a strain with almost all the genetic information fused into one single chromosome by editing the genome – in other words, successive end-to-end chromosome fusions and centromere deletions.

A paper about their research was published on the website of the United Kingdom-based Nature on Thursday, and scientists believed it was a milestone breakthrough in synthetic biology field.

“These engineered yeast strains constitute powerful resources for studying fundamental concepts in chromosome biology, including replication, recombination and segregation, all of which have been very important topics in biology for a long time,” said Paul Evans, director of Nature Research Group in China.

Qin Zhongjun, leader of the research group, said the breakthrough provides possible insights into future research of telomeres – the two “caps” on each chromosome – which are closely related to aging and diseases, and the effectiveness of new medications targeting at the “caps”.

“If we can develop future lab animals with the single-chromosome structure, it will be easier and more efficient to estimate the efficacy of the medicine by observing the changes in both ‘caps’ of just one chromosome rather than dozens of them,” he said.