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Hansong Ma

Ma

Hansong Ma PhD, Wellcome Trust Sir Henry Dale Fellow, member of the Department of Genetics.

Lab website 

Europe PMC | PubMed

 

 

  

The genetics of Drosophila mitochondrial DNA and its influence on evolution and disease

In addition to the nuclear genome, all animals have another genome packed inside the mitochondrion called mtDNA. This maternally inherited genome encodes important proteins for energy production. Mutations in mtDNA are responsible for over 50 mitochondrial diseases, affecting 1 in 4,300 of the UK population. 

Given that there are multiple copies of mtDNA in each cell, pathogenic mitochondrial mutations often arise among thousands of wild-type genomes. Once their percentage exceeds a certain threshold, it causes a phenotypic manifestation of the genetic defects. Selectivity in the transmission of functional versus pathogenic genomes in somatic cells affects the expression of disease phenotype as we age. Selective transmission in germline governs the inheritance of mtDNA mutations from mother to progeny, and in this way its evolution. 

Recently, I have developed some genetic tools for mitochondrial studies in Drosophila, which have a mitochondrial genome that is very similar to humans. By artificially mixing different genomes and following their transmission over generations, my lab will use Drosophila to investigate how mitochondrial mutations are inherited. We will also investigate how differences in mitochondrial genotypes contribute to broad-scale organismal phenotypes, such as longevity and fertility. These studies will advance understanding of mitochondrial genetics and provide new insights into mitochondrial disease.

Selected publications:

 • Ma H, O'Farrell PH (2016) Selfish drive can trump function when animal mitochondrial genomes compete. Nat Genet 48(7):798-802.

 • Ma H, O'Farrell PH (2015) Selections that isolate recombinant mitochondrial genomes in animals. Elife 4:e07247.

 • Ma H, Xu H, O'Farrell PH (2014) Transmission of mitochondrial mutations and action of purifying selection in Drosophila melanogaster. Nat Genet 46(4):393-397.

 • Voelz K et al. (2013) Transmission of Hypervirulence traits via sexual reproduction within and between lineages of the human fungal pathogen cryptococcus gattii. PLoS Genet 9(9):e1003771.

 • Ma H, May RC (2010) Mitochondria and the regulation of hypervirulence in the fatal fungal outbreak on Vancouver Island. Virulence (3):197-201.

 • Ma H, Hagen F, Stekel DJ, Johnston SA, Sionov E, Falk R, Polacheck I, Boekhout T,  May RC (2009) The fatal fungal outbreak on Vancouver Island is characterized by enhanced intracellular parasitism driven by mitochondrial regulation. Proc Natl Acad Sci U S A 106(31):12980-12985.

MaGroupJan2017

Plain English

Mitochondria are the “power stations” inside our cells, playing an important role in health and disease. Mitochondria carry their own DNA, which is always inherited from the mother, while the DNA in each cell nucleus is derived equally from the mother and father. Disorders arising from mutant mitochondrial DNA are particularly complicated to understand because each cell contains many mitochondria, each with its own genome, and often normal and mutant mitochondrial genomes exist in a single cell.   

Inheritance of the mitochondrial genome in germline and body tissues is therefore different from conventional inherited disorders, but it is important to understand the process if we are to diagnose and cure mitochondrial diseases.

My lab has developed genetic tools to study mitochondrial inheritance in the fruit fly, which provides a good model for the human mitochondrial genome. I am studying transmission of mitochondrial mutations and how these contribute to disease, longevity and fertility.

Co-workers

Chieh-Yin (Ason) Chiang • Kathy Oswald  • John Overton