Researchers from China have claimed to have created the world’s first single-chromosome yeast while not affecting the majority of its functions.
The researchers involved in the creation are molecular biologists from the Centre for Excellence in Molecular Plant Sciences in China. The research was published on the website of the journal – Nature on August 2, 2018.
• Brewer's yeast, one-third of whose genome is said to share ancestry with humans, has 16 chromosomes.
• However, Chinese scientists have managed to fit nearly all its genetic material into just one chromosome while not affecting the majority of its functions.
• The researchers used CRISPR-Cas9 genome-editing to create a single-chromosome yeast strain.
• Using the CRISPR-Cas9, the research team removed the DNA at the telomeres, the ends of chromosomes that protect them from degrading.
• They also snipped out the centromeres, sequences in the middle that are important to DNA replication.
• First, they fused two chromosomes, then joined the product to another chromosome, and repeated the process in successive rounds until there was only one chromosome left.
• Yeast is a type of eukaryote, which also includes humans, plants, and animals.
• Humans have 46 chromosomes, whereas male jack jumper ants have just one.
• The research revealed that the number of chromosomes of a eukaryote has no correlation with the amount of genetic information they possess.
• It showed that all the genetic information can be concentrated in just one chromosome.
• Researchers have previously fused two yeast chromosomes together but no one has ever performed such a type of extreme genetic surgery where all genetic material is fitted into just one chromosome.
By simplifying a complex genome system, the research provides a new approach to studying the functions of telomeres.
Earlier research found that the length of telomeres is related to early aging, the formation of tumours, and other diseases. Telomeres shorten as a cell splits, but if telomeres cannot shorten anymore, the cell dies.
Hence, the breakthrough could help in furthering research related to aging and diseases in humans.
It may also pave the way for new man-made species in the future.