title: Host Mitochondrial Association Evolved in the Human Parasite Toxoplasma gondii via Neofunctionalization of a Gene Duplicate.
abstract: In Toxoplasma gondii, an intracellular parasite of humans and other animals, host mitochondrial association (HMA) is driven by a gene family that encodes multiple mitochondrial association factor 1 (MAF1) proteins. However, the importance of MAF1 gene duplication in the evolution of HMA is not understood, nor is the impact of HMA on parasite biology. Here we used within- and between-species comparative analysis to determine that the MAF1 locus is duplicated in T. gondii and its nearest extant relative Hammondia hammondi, but not another close relative, Neospora caninum Using cross-species complementation, we determined that the MAF1 locus harbors multiple distinct paralogs that differ in their ability to mediate HMA, and that only T. gondii and H. hammondi harbor HMA(+) paralogs. Additionally, we found that exogenous expression of an HMA(+) paralog in T. gondii strains that do not normally exhibit HMA provides a competitive advantage over their wild-type counterparts during a mouse infection. These data indicate that HMA likely evolved by neofunctionalization of a duplicate MAF1 copy in the common ancestor of T. gondii and H. hammondi, and that the neofunctionalized gene duplicate is selectively advantageous.
authors.affiliation: Department of Biological Sciences, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260.
authors.forename: Yaw
authors.initials: Y
authors.lastname: Adomako-Ankomah
authors.affiliation: Department of Biological Sciences, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260.
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: English
authors.affiliation: Department of Biological Sciences, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Danielson
authors.affiliation: Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305.
authors.forename: Lena F
authors.initials: LF
authors.lastname: Pernas
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, VP8 5C2, Canada.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Parker
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, VP8 5C2, Canada.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Boulanger
authors.affiliation: Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, US Department of Agriculture, Beltsville, Maryland 20705.
authors.forename: Jitender P
authors.initials: JP
authors.lastname: Dubey
authors.affiliation: Department of Biological Sciences, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 boylej@pitt.edu.
authors.forename: Jon P
authors.initials: JP
authors.lastname: Boyle
mesh_terms: D000818:Animals; D002415:Cats; D018628:Gene Dosage; D020440:Gene Duplication; D005786:Gene Expression Regulation; D006790:Host-Parasite Interactions / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D005810:Multigene Family; D015800:Protozoan Proteins / Q000235:genetics*; D014122:Toxoplasma / Q000235:genetics*; D014123:Toxoplasmosis / Q000469:parasitology*; D014158:Transcription, Genetic
chemical_list: D015800:Protozoan Proteins
keywords: Hammondia hammondi; Neospora caninum; Toxoplasma gondii; gene duplication; neofunctionalization