INVESTIGADORES
ABRAHAM Solana
artículos
Título:
Evolution of pre-zygotic and post-zygotic barriers to gene flow among three cryptic species within the Anastrepha fraterculus complex
Autor/es:
RULL JUAN; ABRAHAM SOLANA; KOVAKESKI ADALECIO; SEGURA DIEGO; MENDOZA MARIANA; LIENDO MARIA CLARA; VERA MARIA TERESA
Revista:
ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2013 vol. 148 p. 213 - 222
ISSN:
0013-8703
Resumen:
Tropical tephritids are ideally suited for studies on population divergence and speciation because they
include species groups undergoing rapid radiation, in which morphologically cryptic species and sister
species are abundant. The fraterculus species group in the Neotropical genus Anastrepha is a case
in point, as it is composed of a complex of up to seven A. fraterculus morphotypes proposed to be
cryptic species. Here, we document pre- and post-zygotic barriers to gene flow among adults of the
Mexican A. fraterculus morphotype and three populations (Argentina, Brazil, and Peru) belonging
to two separate morphotypes (Brazilian 1 and Peruvian). We unveiled three forms of pre-zygotic
reproductive isolation resulting in strong assortative mating. In field cages, free-ranging male and
female A. fraterculus displayed a strong tendency to form couples with members of the opposite sex
belonging to their own morphotype, suggesting that male pheromone emission, courtship displays,
or both intervene in shaping female choice before actual contact and coupling. In addition, males
and females of the Peruvian morphotype became receptive and mated significantly later than adults
of the Mexican and Brazilian 1 morphotypes. After contact, Mexican females exhibited greater mating
discrimination than males when facing adults of the opposite sex belonging to either the Peruvian
or the Brazilian 1 morphotype as evidenced by vigorous resistance to penetration once they had been
forcefully mounted by heterotypic males. Forced copulations resulted in production of F1 hybrids
that were either less viable (and partially fertile) than parental crosses or even sterile. Our results
suggest that the Mexican morphotype is a distinct biological entity and that pre-zygotic reproductive
isolation through divergence in courtship or male-produced pheromone and other mechanisms
appear to evolve faster than post-zygotic isolation in the fraterculus species group.