Korean Journal of Microbiology (미생물학회지)

The Microbiological Society of Korea (한국미생물학회)
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Characterization of the Neurospora crassa rcm-1 Mutants

Neurospora crassa rcm-1 돌연변이체의 특성

  • Kim Sang-Rae (Division of Biological Sciences, Kosin University) ;
  • Lee Bheong-Uk (Division of Biological Sciences, Kosin University)
  • 김상래 (고신대학교 자연과학대학 생명과학부) ;
  • 이병욱 (고신대학교 자연과학대학 생명과학부)
  • Published : 2005.12.01
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Abstract

Analysis of the complete genome of Neurospora crassa reveals that at least 19 proteins contain tetratricopeptide repeat (TPR) motifs. One of them shows over $60\%$ homology to Ssn6 of Saccharomyces cerevisiae, a universal repressor that mediates repression of genes involved in various cellular processes. Mutant strains generated by RIP (repeat-induced point mutation) process showed four distinctive vegetative growth patterns and slow growth in various rates. Firstly, a mutant showed denser mycelial growth, yellow, csp, and looked like ropy mutant. Secondly, slower growth, dense mycelial, and conidial phenotype. Thirdly, extremely slower growth and aconidial. And finally, flat, tittle aerial hyphae, acon, and similar with a rco-1 RIP mutant. They are all male-fertile, yet female-sterile and produced little or no perithecium. It seems that various phenotypes were occurred depending upon mostly likely, the degree of RIP. These results indicate that this gene may be involved in several cellular possess during vegetative growth, and asexual and sexual development. Therefore it is pleiotropic. Sequence analysis of cDNA shows that it encodes a putative 102 kDa protein composed of 917 amino acids, and has six introns. It is designated rcm-1 (regulation of conidiation and morphology).

Neurospora crassa의 게놈 분석을 통하며 tetratricopeptide repeat (TPR) 부위를 보유할 것으로 추정되는 19중의 단배질을 찾아냈다. 이중에서 한 단백질은 Saccharomyces cerevisiae에서 다양한 유전자들의 공통 전사 억제인자로 알려진 Ssn6 단백질에 $60\%$ 이상의 유사도를 보였다. N. crassa의 RIP (repeat-induced point mutation) 과정을 통하여 생산된 돌연변이 균주들은 도두 느리게 성장하였는데, 4가지로 구분되는 돌연변이 표현형을 나타냈다. 첫 번째 돌연변이 표현형은 균사가 ropy돌연변이와 유사한 균사 모양으로 성장하고 밀도가 높아 보였고, 대분생포자는 yellow와 csp 표현형을 보였다. 두 번째 돌연변이형은 늦은 성장을 보였지만 대분생포자를 생산하였다. 세 번째는 매우 느린 균사 성장을 보였고 acon 표현형을 나타냈다. 마지막 돌연변이형은 거의 공기 중으로 균사를 뻗지 못하였으며 acon 표현형을 보였는데, rco-1 RIP 돌연변이체와 유사하였다. 돌연변이체들은 모두 male로서는 수정능을 보였지만 female로서는 교배가 불가능했으며 자낭각을 생산하지 못하였다. 이 결과들은 이 유전자가 N. crassa의 성장은 물론 무성생식 및 유성생식의 여러 과정에 관여함을 나타낸다. 염색체와 cDNA의 서열을 분식한 결과에 따르면, 유전자가 6개의 인트론을 보유하고 있고, 총917개의 아미노산으로 구성된 102kDa의 단백질을 암호화할 것으로 예상되었다. 이 유전자를 rcm-1 (regulation of conidiation and morphology)으로 명명하였다.

Keywords

References

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