Sexual reproduction between partners of the same mating type in Cryptococcus neoformans (Nature, 434:1017-1021, 21 April 2005)

報告日期: 2005/09/27
報告時間: 15:10/16:00
報告學生: 楊亞倫(英)
講評老師: 許明隆
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Sexual reproduction between partners of the same mating

type in Cryptococcus neoformans

Nature. 434, 1017-21 (2005)

 

SpeakerYah-Luen Yang                    Date94.09.27  PM 3:10-4:00

CommentatorDr. Ming-Long Hsu            placeRoom 602

 

Abstract

Cryptococcus neoformans is a basidiomycetous fungus and that globally distributed human fungal pathogen that causes life-threatening meningoencephalitis in immunocompromised patients. (1) It has a defined sexual cycle involving haploid cells of α and a mating types. yet the vast majority of environmental and clinical isolates are α . (2) When nutrients are limiting, α and a cells secrete pheromones that trigger cell–cell fusion. Meanwhile, fruiting and mating among the C. neoformans are playing an extremely important role in the pathogenic course. (3) Though this of the words, under single mating type limited feeling, how to carry on sexual cycle under the natural environment? In this paper, the authors utilizes FACS and microdissection method to verify and propose nuclear diploidization occurs during monokaryotic fruiting and might directly promote filamentation. On the other hand, the study group identified and synthesized the lipid modified peptide pheromone that activates cascade. They conclude that the pheromone response pathway functions before cell or nuclear fusion during fruiting and suggest pheromone signaling might play an analogous role in C. neoformans fruiting. At the same time, the importance of meiotic recombination that gene mutation observes basidium and forms basidospore chain situation to prove by DMC1 gene. Finally, the authors propose that the sexual recombination of C. neoformans is through mating and fruiting. These studies reveal how sexual reproduction can occur between partners of the same mating type. These findings have implications for the evolution of microbial pathogens, as well as for parthenogenesis, cell fusion events and transitions between self-fertilizing and outcrossing modes of reproduction observed in both fungi and other kingdoms.

 

 

References

1.         Casadevall, A. et al., ASM Press, Washington, DC, 1998.

2.         Kwon-Chung, K. J. et al., Am. J. Epidemiol. 108, 337–340 (1978).

3.         Wickes, B. L. et al., Proc.Natl Acad. Sci. USA 93, 7327–7331 (1996).