Polymorphism at the self-incompatibility locus in Solanaceae predates speciation.
Proc Natl Acad Sci U S A
; 87(24): 9732-5, 1990 Dec.
Article
en En
| MEDLINE
| ID: mdl-2263623
Sequences of 11 alleles of the gametophytic self-incompatibility locus (S locus) from three species of the Solanaceae family have recently been determined. Pairwise comparisons of these alleles reveal two unexpected observations: (i) amino acid sequence similarity can be as low as 40% within species and (ii) some interspecific similarities are higher than intraspecific similarities. The gene genealogy clearly illustrates this unusual pattern of relationships. The data suggest that some of the polymorphism at the S locus existed prior to the divergence of these species and has been maintained to the present. In support of this hypothesis, the number of shared polymorphic sites was found to exceed the number found in simulations with independent accumulation of mutations. Strictly neutral evolution is exceedingly unlikely to maintain the polymorphism for such a long time. The allele multiplicity and extreme age of the alleles is consistent with Wright's classic one-locus population genetic model of gametophytic self-incompatibility. Similarities between the plant S locus and the mammalian major histocompatibility complex are discussed.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
/
Plantas
/
Polimorfismo Genético
/
Evolución Biológica
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
1990
Tipo del documento:
Article
Pais de publicación:
Estados Unidos