Gamete compatibility and sperm competition affect paternity and hybridization between sympatric Asterias sea stars.
Biol Bull
; 209(2): 113-26, 2005 Oct.
Article
em En
| MEDLINE
| ID: mdl-16260771
ABSTRACT
Gamete interactions may strongly influence speciation and hybridization in sympatric broadcast-spawning marine invertebrates. We examined the role of gamete compatibility in species integrity using cross-fertilization studies between sympatric Asterias sea stars from a secondary contact zone in the northwest Atlantic. In crosses between single males and single females, gametes of both species were compatible and produced viable, fertile hybrid offspring, but with considerable variation in the receptivity of eggs to heterospecific sperm. Differential compatibility of heterospecific gametes was detected in sperm competition studies in which we used a nuclear DNA marker to assign paternity to larval offspring. Several families showed conspecific sperm precedence in A. forbesi eggs, and one family showed competitive superiority of A. forbesi sperm fertilizing A. rubens eggs. Gametic interactions are an important component of prezygotic reproductive isolation in sympatric Asterias. The interaction between gametes of these closely related sea stars is consistent with the function of gamete recognition systems that are known to mediate fertilization success and speciation in other marine invertebrates.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Espermatozoides
/
Estrelas-do-Mar
/
Hibridização Genética
Limite:
Animals
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Biol Bull
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Canadá