backResearcher Profile

Don Stewart

Job Title: Assistant Professor
Employer: Acadia University
Place of Birth: Halifax, Nova Scotia, Canada
High School attended: Windsor Regional
Further Education: Acadia University (B.Sc.), University of Toronto (Ph.D.).
Geographic focus of research: Maritime Provinces (Nova Scotia, Prince Edward Island, New Brunswick)

Brief synopsis of current research:
My current research programme focuses on patterns and rates of molecular evolution in bivalve mollusks, particularly freshwater (Unionidae) and marine (Mytilidae) mussels. These bivalve have been shown to exhibit an unusual system of mitochondrial DNA inheritance in which males are heteroplasmic (i.e., contain two types of mtDNA, their fatherís and motherís) but only transmit their fatherís mtDNA in their sperm. Females only transmit their motherís mtDNA. The system is complicated by the fact that maternally transmitted mtDNA genomes occasionally ďsneakĒ into the paternal route of inheritance. I am using phylogenetic techniques to try to pin down the origin of this unusual mode of mitochondrial DNA transmission and am also investigating a possible connection between this system of mtDNA inheritance and the unusually high rate of molecular evolution observed in these mussels.

Mailing address:
Biology Department, Acadia University, Wolfville, NS B0P 1X0



Recent Publications:

Garrido-Ramos, M., D.T. Stewart, B.W. Sutherland, and E. Zouros. 1998. The distribution of male-transmitted and female-transmitted mitochondrial DNA types in somatic tissues of blue mussels: Implications for the operation of doubly uniparental inheritance of mitochondrial DNA. Genome 41: 818-824

Sutherland, B.W., D.T. Stewart, M. Garrido-Ramos, and E. Zouros. 1998. The fate of paternal mitochondrial DNA in developing female mussels, Mytilus edulis. Genetics 148: 341-348.

Hoeh, W.R., D.T. Stewart, B.S. Sutherland, and E. Zouros. 1997. Phylogenetic evidence for role-reversals of gender-associated mitochondrial DNA in Mytilus (Bivalvia: Mytilidae). Molecular Biology and Evolution 14: 959-967.

Stewart, D.T., E. Kenchington, R. Singh, and E. Zouros. 1996. Degree of selective constraint as an explanation of the different rates of evolution of gender-specific mitochondrial DNA lineages in the mussel Mytilus. Genetics 143:1349-1357.

Stewart, D.T. , C. Saavedra, R.R. Stanwood, A.O. Ball, and E. Zouros. 1995. Male and female mitochondrial DNA lineages in the Blue Mussel Mytilus. Molecular Biology and Evolution 12: 735-747.