Abstract
Theoretical considerations suggest that a high load of deleterious mutations should accumulate in asexual genomes. An ideal system for testing this hypothesis occurs in the hybrid all-female fish Poeciliopsis monacha-lucida. The hybrid genotype is retained between generations by an oogenetic process that transmits only a nonrecombinant haploid monacha genome to their ova. The hybrid genotype is re-established in nature by fertilization of these monacha eggs with sperm from a sexual species, P. lucida. The unique reproductive mechanism of these hybrids allows the genetic dissection of the clonal monacha genome by forced matings with males of P. monacha. The resultant F1 hybrids and their backcross progeny were examined to determine the amount and kinds of genetic changes that might have occurred in two clonal monacha genomes.—Using six allozyme markers, four similar linkage groups were identified in each clonal genome. Segregation and assortment at these loci revealed no apparent differences between monacha genomes from sexually and clonally reproducing species. Mortality of F1 and backcross progeny revealed differences between the two clonal genomes, suggesting that deleterious genes may accumulate in genomes sheltered from recombination.
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Selected References
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- Anderson W. W. Genetics of natural populations xli. The selection coefficients of heterozygotes for lethal chromosomes in Drosophila on different genetic backgrounds. Genetics. 1969 Aug;62(4):827–836. doi: 10.1093/genetics/62.4.827. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CLARK E. A method for artificial insemination in viviparous fishes. Science. 1950 Dec 15;112(2920):722–723. doi: 10.1126/science.112.2920.722. [DOI] [PubMed] [Google Scholar]
- Leslie J. F., Vrijenhoek R. C. Genetic analysis of natural populations of Poeciliopsis monacha: Allozyme inheritance and pattern of mating. J Hered. 1977 Sep-Oct;68(5):301–306. doi: 10.1093/oxfordjournals.jhered.a108841. [DOI] [PubMed] [Google Scholar]
- Parker E. D., Jr, Selander R. K. The organization of genetic diversity in the parthenogenetic lizard Cnemidophorus tesselatus. Genetics. 1976 Dec;84(4):791–805. doi: 10.1093/genetics/84.4.791. [DOI] [PMC free article] [PubMed] [Google Scholar]