Science and Technology Daily, Beijing, November 8th (Reporter Zhang Jiaxin) - Researchers from the United States and the UK combined more than 7 synthetic chromosomes manufactured in the laboratory into a yeast cell, producing a "semi artificial" strain that synthesizes over 50% of its DNA. It has the same survival and replication ability as natural yeast strains. The team has now synthesized and debugged all 16 yeast chromosomes, which means they are one step closer to creating the world's first synthetic yeast genome and unraveling the fundamental components of life. The research results were published in the journal Cell on the 8th, and the same collection of papers were also published in the journals Molecular Cell and Cell Genomics. This is the first construction of a synthetic genome for eukaryotes. Yeast has a relatively compact genome and the innate ability to stitch DNA together, allowing researchers to construct synthetic chromosomes in yeast cells. The tRNA new chromosome, which was created by the team of the Langney School of Health of New York University in the United States and the University of Manchester in the United Kingdom, is a new chromosome different from the natural chromosome. They removed non coding DNA blocks and repetitive elements that were considered "junk", added new DNA fragments, and introduced a built-in diversity generator that can disrupt the genetic order within and between chromosomes. To improve genomic stability, the team also removed many genes encoding transfer RNA and transferred them back to a brand new chromosome composed solely of tRNA genes. The yeast genome is composed of 16 chromosomes, and researchers plan to create synthetic yeast strains, each containing 15 natural chromosomes and 1 synthetic chromosome. They gradually integrated all previously synthesized chromosomes (6 intact chromosomes and 1 chromosome arm) into one cell. The synthesis rate of the obtained yeast strain exceeds 31%, exhibiting normal morphology and only showing slight growth defects compared to natural yeast. In order to more effectively transfer specific chromosomes between yeast strains, they used chromosome replacement methods to transfer newly synthesized chromosomes (chromosome IV, the largest of all synthetic chromosomes), resulting in yeast cells with 7.5 synthetic chromosomes, with a synthesis rate of over 50%. In addition, a team led by Dr. Ben Blunt from the University of Nottingham in the UK and Professor Tom Ellis from Imperial College London reported synthetic chromosome XI in the journal Cell Genomics. Next, researchers will work together to combine all individual synthetic chromosomes into a fully synthesized genome. The final synthetic strain is not only the world's first synthetic eukaryote, but also the first strain jointly constructed by the international community. (New News Agency)