DNA recombination protein-dependent mechanism of homoplasmy and its proposed functions.
Homoplasmy is a basic genetic state of mitochondria, in which all of the hundreds to thousands of mitochondrial (mt)DNA copies within a cell or an individual have the same nucleotide-sequence. It was recently found that "vegetative segregation" to generate homoplasmic cells is an active process under genetic control. In the yeast Saccharomyces cerevisiae, the Mhr1 protein which catalyzes a key reaction in mtDNA homologous recombination, plays a pivotal role in vegetative segregation. Conversely, within the nuclear genome, homologous DNA recombination causes genetic diversity. Considering these contradictory roles of this key reaction in DNA recombination, possible functions of homoplasmy are discussed.
Shibata
Takehiko
T
Cellular & Molecular Biology Laboratory, RIKEN (The Institute of Physical and Chemical Research), Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan. tshibata@postman.riken.go.jp
Ling
Feng
F
D020090:Chromosome Segregation / Q000502:physiology; D004261:DNA Replication; D044708:DNA, Concatenated / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000235:genetics* / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism*; D011995:Recombination, Genetic / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
D044708:DNA, Concatenated; D004272:DNA, Mitochondrial; C417727:MHR1 protein, S cerevisiae; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors