Identification of the minimalized essential unit for genetic inheritance of artificial mini-chromosomes

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K22402
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 43:Biology at molecular to cellular levels, and related fields
• Research Institution: Kindai University
• Principal Investigator: Shinohara Miki 近畿大学, 農学部, 教授 (80335687)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Keywords: 減数分裂期 / 相同組換え / 人工染色体 / 染色体分配

Outline of Final Research Achievements

In eukaryotes, Saccharomyces cerevisiae allows the construction of fully artificially synthesized chromosomes using the minimum regions of the basic units of chromosomal function such as replication origin, centromeres, and telomeres. Here we show that the artificial mini-chromosomes show frequent non-disjunction of homologs during the first division of meiosis while normal segregation during the second division. In addition, since the cause of non-disjunction was considered to be meiotic crossover recombination deficiency, UAS sequence of the GAL1 promoter was inserted on the artificial mini-chromosome and analyzed chromosome segregation in Gal4-BD-Spo11 expressing strains, but no improvement was observed. On the other hand, autophosphorylation-mediated activation of the chromosomal axis factor Mek1 kinase plays an important role in template selection for meiotic recombination, revealing that ectopic recombination occurs frequently in the phosphorylation-deficient mek1 mutant.

Free Research Field

分子遺伝学

Academic Significance and Societal Importance of the Research Achievements

1真核生物の中でセントロメア、テロメア、複製開始点など染色体の必須要素が明らかになっている出芽酵母で、人工染色体にさまざまな人工DNA配列を付加することによって引き起こされる減数分裂期組換えの挙動の変化について解析を行うことで、細胞内における染色体サイズの認識とそれに応じた交叉型組換え制御機構について明らかにし、次世代に継承可能にするための最小のゲノム要素を明らかにすることができる。