|Budget Amount *help
¥30,100,000 (Direct Cost: ¥30,100,000)
Fiscal Year 1989: ¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 1988: ¥9,200,000 (Direct Cost: ¥9,200,000)
Fiscal Year 1987: ¥16,800,000 (Direct Cost: ¥16,800,000)
This project aims to understand the mechanisms underlying meiotic recombination, focusing the molecular events of chromosome pairing and chiasma formation. The followings are the results obtained and the experiments on progress, using lily microsporocytes, mouse spermatocytes and yeast.
1) Using two mutant plasmids of pBR322, mutl and mut2, both are tetracycle sensitive, and cell extracts or proteins, recombination activity was determined by measuring the appearance of Tc resistant colonies after transformation of rec strain of E coli with the incubated DNA. We intend to clone the gene(s) of this protein(s) but the experiment is still on progress. The delay is due to the lack of enzyme preparation. By the same reason, the preparation of anti-body against this protein still continues.(1,2,3,11,19,21,22)
2) However, the analysis of this protein was advanced. Specificity of the reaction for temperature, feature of substrate DNA, and relations to other enzymes became evident. These results a
re important to understand the physiology of germ cell differentiation and fertility.(4,5,6,10,11,12,13)
3) We have found the presence of two recA like proteins, ATP-dependent (m-rec) and ATP-independent (mAi-rec), and their behavior (D-loop formation and strand transfer activities) during meiosis and their cellular localization were studied in relation to meiotic recombination. We have also identify the proteins act on recombination with and without Mg^<++>, which makes the number of recombinatory proteins to four (or more). Also, the presence and alteration of two DNA ligases have been analyzed and specific function of ligase II for meiotic recombination has been speculated.(7,8,9,20,21)
5) Isolation of synaptonema complex (S.C.) and the SDS-PAGE analysis of S.C. protein(s) and the preparation of anti-bodies have been completed.
6) Using protoplasts and mini-protoplasts, chromosome transfer has been successfully completed in reproductive cells.(13,14,15,16,23).
7) The detailed analysis of yeast cell morphogenesis has been completed nd the basic information for meiotic induction is accumulated.(17,18) Less