• Journal of Microbiology
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• v.33 no.3
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• pp.196-200
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• 1995

In order to express the CDC70 gene of Saccharomyces cerevisiae by heat shock, we have designed heat inducibe hybrid promoters using the Drosophila melanogaster heat shock elements (HSEs). A 220 bp-long upstream fragment of the D. melanogaster hsp70 gene comprised of four HSEs was placed upstream of the putative proximal TATA box of the CDC70 gene. Hybrid promoters containing different fusion joints were tested for their ability to drive the CDC70 gene expression by heat shock. The results showed that the HSEs of D. melanogaster conferred the heat-induced CDC70 gene expression, but the heat inducibility was much lower than that in D. melanogaster.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.210-215
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• 1989

In order to elucidate and characterize the signal transduction pathway(s) whereby yeast cells respond to mating pheromone, we have isolated mutants which are able to conjugate in the absence of the alpha-factor receptor. Sixty-one suppressors of a ste2-deletion mutation which also confer a ts conditional "start" arrest phenotypw have been subjected to genetic analysis. The mutants could be assigned to three complementation groups designated CDC70, CDC72 and CDC73, which are unlinked to each other as well as to the previously identified start genes. Quantitation of mating ability of the cdc70, cdc72 and cdc73 mutations in a ste2-deletion background gives levels ranging from 0.1% to 0.3% of wild type, depending on the allele and the gene. The results indicate that the signals from mating pheromone might be mediated by the CDC70, CDC72 and CDC73 products. products.

• The Korean Journal of Mycology
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• v.19 no.4
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• pp.266-275
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• 1991

The gene CDC70 encoding the${\alpha}-subunit$ of G protein has been known to be a component involved in mating pheromone signalling in the yeast, Saccharomyces cerevisiae. To isolate mutations of the genes involved in the signal transduction, Saccharomyces cerevisiae the strain bearing the cdc70-5 mutation was mutagenized to be forced to recover the ability of colony-formation at restrictive temperature, which means the new mutation can suppress the temperature sensitivity of the cdc70-5 phenotypes. Among these suppressors, $sir^-$ and $mat{\alpha}2^{-}$ mutations are excluded because of no relationship to signal transducer. And the selected suppressors were analyzed for the linkage relationships by the tetrad analysis. Out of fifteen suppressors isolated, twelve were classified into four linkage groups, designated as sga1, sga2, sga3, sga4 by the tetrad analysis. The other three genes were determined for the linkage.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.33-45
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• 2011

Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of cancer cell. Inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the cancer cell was reported. However, its role during oocyte maturation and early embryo development is very insufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on meiotic maturation and early embryonic development in pigs. We also investigated several indicators of developmental potential, including structural integrity, gene expression (Hsp90-, cell cycle-, and apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Then, we examined the roles of Hsp90 inhibitor on viability of primary cells in pigs. Porcine oocytes were cultured in the NCSU-23 medium with or without 17-AAG for 44 h. The proportion of GV arrested oocytes was significantly different between the 17-AAG treated and untreated group (78.2 vs 34.8%, p<0.05). After completion of meiotic maturation, the proportion of MII oocytes was lower in the 17-AAG treated group than in the control group (27.9 vs 71.0%, p<0.05). After IVF, the percentage of penetrated oocytes was significantly lower in the 17-AAG treated group (25.2%), resulting in lower normal pronucleus formation (2PN of 14.6%). Therefore, the inhibition of meiotic progression by Hsp90 inhibitor played a critical role in fertilization status. Porcine embryo were cultured in the PZM-3 medium with or without 17-AAG for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (7.5 vs 4.4, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation porcine blastocysts. The mRNA expressions of cell cycle-related genes were down-regulated in the 17-AAG treated group compared with control. Also, the expression of the pro-apoptotic gene Bax increased in 17-AAG treated group, whereas expression of the anti-apoptotic gene Bel-XL decreased. However, the expression of ER stress-related genes did not changed by 17-AAG. Cultured pESF cells were treated with or without 17-AAG and used for MIT assay. The results showed that viability of pESF cells were decreased by treatment of 17-AAG ($2{\mu}M$) for 24 hr. These results indicated that 17-AAG decreased cell proliferation and increased cell death. Expression patterns Hsp90 complex genes (Hsp70 and p23), cell cycle-related genes (cdc2 and cdc25c) and apoptosis-related genes (Bax and Bcl-XL) were significantly changed by using RT-PCR analysis. The spliced form of pXbp-1 product (pXbp-1s) was detected in the tunicamycin (TM) treated cells, but it is not detected in 17-AAG treated cells. In conclusion, Hsp90 appears to play a direct role in porcine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with cell cycle- and apoptosis-related genes expression in developing porcine embryos.