EXTRANUCLEAR DIFFERENTIATION AND GENE FLOW IN THE FINITE ISLAND MODEL

Naoyuki Takahata ¹ and Stephen R. Palumbi ¹

¹ Department of Zoology, NJ-15, University of Washington, Seattle, Washington 98195

Use of sequence information from extranuclear genomes to examine deme structure in natural populations has been hampered by lack of clear linkage between sequence relatedness and rates of mutation and migration among demes. Here, we approach this problem in two complementary ways. First, we develop a model of extranuclear genomes in a population divided into a finite number of demes. Sex-dependent migration, neutral mutation, unequal genetic contribution of separate sexes and random genetic drift in each deme are incorporated for generality. From this model, we derive the relationship between gene identity probabilities (between and within demes) and migration rate, mutation rate and effective deme size. Second, we show how within- and between-deme identity probabilities may be calculated from restriction maps of mitochondrial (mt) DNA. These results, when coupled with our results on gene flow and genetic differentiation, allow estimation of relative interdeme gene flow when deme sizes are constant and genetic variants are selectively neutral. We illustrate use of our results by reanalyzing published data on mtDNA in mouse populations from around the world and show that their geographic differentiation is consistent with an island model of deme structure.

This article has been cited by other articles:

				S. Setsuko, K. Ishida, S. Ueno, Y. Tsumura, and N. Tomaru Population differentiation and gene flow within a metapopulation of a threatened tree, Magnolia stellata (Magnoliaceae) Am. J. Botany, January 1, 2007; 94(1): 128 - 136. [Abstract] [Full Text] [PDF]

				M. E. Welch, M. Z. Darnell, and D. E. McCauley Variable Populations Within Variable Populations: Quantifying Mitochondrial Heteroplasmy in Natural Populations of the Gynodioecious Plant Silene vulgaris Genetics, October 1, 2006; 174(2): 829 - 837. [Abstract] [Full Text] [PDF]

				D. Roze, F. Rousset, and Y. Michalakis Germline Bottlenecks, Biparental Inheritance and Selection on Mitochondrial Variants: A Two-Level Selection Model Genetics, July 1, 2005; 170(3): 1385 - 1399. [Abstract] [Full Text] [PDF]

				M. B. Hamilton and J. R. Miller Comparing Relative Rates of Pollen and Seed Gene Flow in the Island Model Using Nuclear and Organelle Measures of Population Structure Genetics, December 1, 2002; 162(4): 1897 - 1909. [Abstract] [Full Text] [PDF]

				J. G. Marquez and E. S. Krafsur Gene Flow Among Geographically Diverse Housefly Populations (Musca domestica L.): A Worldwide Survey of Mitochondrial Diversity J. Hered., July 1, 2002; 93(4): 254 - 259. [Abstract] [Full Text] [PDF]

				M. E. Orive and M. A. Asmussen The Effects of Pollen and Seed Migration on Nuclear-Dicytoplasmic Systems. II. A New Method for Estimating Plant Gene Flow From Joint Nuclear-Cytoplasmic Data Genetics, June 1, 2000; 155(2): 833 - 854. [Abstract] [Full Text]

				X.-S. Hu and R. A. Ennos Impacts of Seed and Pollen Flow on Population Genetic Structure for Plant Genomes With Three Contrasting Modes of Inheritance Genetics, May 1, 1999; 152(1): 441 - 450. [Abstract] [Full Text]

				R. K. Chesser Heteroplasmy and Organelle Gene Dynamics Genetics, November 1, 1998; 150(3): 1309 - 1327. [Abstract] [Full Text]