Uniparental mitochondrial DNA inheritance is not affected in Ustilago maydis Δatg11 mutants blocked in mitophagy

BMC Microbiology

Christoph W Basse¹  Jörg Kämper¹  Frauke Lämmer¹  Gaby Wagner-Vogel¹ 

[1] Department of Genetics, Institute for Applied Biosciences of the Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

关键词: Atg11;    Fungi;    Ustilago maydis;    mtDNA;    Uniparental mitochondrial inheritance;    Mitophagy;   

Others  :  1137439
DOI  :  10.1186/s12866-015-0358-z

 received in 2014-11-12, accepted in 2015-01-22,  发布年份 2015

【 摘 要 】

Background

Maternal or uniparental inheritance (UPI) of mitochondria is generally observed in sexual eukaryotes, however, the underlying mechanisms are diverse and largely unknown. Recently, based on the use of mutants blocked in autophagy, it has been demonstrated that autophagy is required for strict maternal inheritance in the nematode Caenorhabditis elegans. Uniparental mitochondrial DNA (mtDNA) inheritance has been well documented for numerous fungal species, and in particular, has been shown to be genetically governed by the mating-type loci in the isogamous species Cryptococcus neoformans, Phycomyces blakesleeanus and Ustilago maydis. Previously, we have shown that the a2 mating-type locus gene lga2 is decisive for UPI during sexual development of U. maydis. In axenic culture, conditional overexpression of lga2 triggers efficient loss of mtDNA as well as mitophagy. To assess a functional relationship, we have investigated UPI in U. maydis Δatg11 mutants, which are blocked in mitophagy.

Results

This study has revealed that Δatg11 mutants are not affected in pathogenic development and this has allowed us to analyse UPI under comparable developmental conditions between mating-compatible wild-type and mutant strain combinations. Explicitly, we have examined two independent strain combinations that gave rise to different efficiencies of UPI. We demonstrate that in both cases UPI is atg11-independent, providing evidence that mitophagy is not critical for UPI in U. maydis, even under conditions of strict UPI.

Conclusions

Until now, analysis of a role of mitophagy in UPI has not been reported for microbial species. Our study suggests that selective autophagy does not contribute to UPI in U. maydis, but is rather a consequence of selective mtDNA elimination in response to mitochondrial damage.

【 授权许可】

   
2015 Wagner-Vogel et al.; licensee BioMed Central.

【 图 表 】

Figure 1.

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