Trans-specificity at loci near the self-incompatibility loci in Arabidopsis. Genetics

Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom.
Genetics (Impact Factor: 5.96). 05/2006; 172(4):2699-704. DOI: 10.1534/genetics.105.051938
Source: PubMed


We compared allele sequences of two loci near the Arabidopsis lyrata self-incompatibility (S) loci with sequences of A. thaliana orthologs and found high numbers of shared polymorphisms, even excluding singletons and sites likely to be highly mutable. This suggests maintenance of entire S-haplotypes for long evolutionary times and extreme recombination suppression in the region.

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Available from: Jenny Hagenblad
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    • "An equivalent phenomenon can be observed in absence of contemporary gene flow, when ancestral polymorphisms have been maintained during past speciation events (Avise and Robinson 2008; Fig. 1B). Known examples of incomplete lineage sorting of adaptive significance mostly include alleles under long-term balancing selection such as in plant / plant pathogen recognition systems (Stahl et al. 1999; Rose et al. 2007; Horger et al. 2012), major histocompatibility complexes in mammals (Edwards et al. 1997; Loisel et al. 2006), AB-blood type defining enzymes and viral response factors in primates (Newman et al. 2006; Ferrer-Admetlla et al. 2009; Segurel et al. 2012), photoreceptors sustaining color vision in New World monkeys (Hunt et al. 1998), and self-incompatibility genes in plants and fungi (Wu et al. 1998; Schierup et al. 2001; Charlesworth et al. 2006; Igic et al. 2006). The recent development of methods dedicated to the detection of ancestral polymorphisms should yield to better estimates of the frequency of this phenomenon (Scally et al. 2012; Segurel et al. 2012). "
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    • "Numerous tests in Arabidopsis sporophytic SI systems have yielded scant evidence for recombination (Kamau and Charlesworth, 2005; Charlesworth et al., 2006; Hagenblad et al., 2006; Edh et al., 2009). Recombination has been detected in SI loci of Brassica species (Kusaba et al., 1997; Awadalla and Charlesworth, 1999; Takuno et al., 2007) but only in genes or gene domains that do not play a direct role in self-incompatibility specificity (Takuno et al., 2007; Edh et al., 2009). "
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