Maladapted gene complexes within populations of the intertidal copepod Tigriopus californicus?
Evolution
; 63(8): 2184-92, 2009 Aug.
Article
em En
| MEDLINE
| ID: mdl-19453379
ABSTRACT
The prevalence of F2 hybrid breakdown in interpopulation crosses of the marine copepod Tigriopus californicus can be explained by disruption of coadapted gene complexes. This study further dissects the nature of hybrid gene interactions, revealing that parental populations may also harbor maladapted gene complexes. Diagnostic molecular markers (14) were assayed in reciprocal F2 hybrids to test for gene interactions affecting viability. Results showed some evidence of nuclear-nuclear coadaptation. Although there were no significant examples of pairwise linkage disequilibrium between physically unlinked loci, one of the two reciprocal crosses did show an overall excess of parental double homozygotes and an overall dearth of nonparental double homozygotes. In contrast, the nuclear-cytoplasmic data showed a stronger tendency toward maladaptation within the specific inbred lines used in this study. For three out of four loci with significant frequency differences between reciprocal F2, homozygotes were favored on the wrong cytoplasmic background. A separate study of reciprocal backcross hybrids between the same two populations (but different inbred lines) revealed faster development time when the full haploid nuclear genome did not match the cytoplasm. The occurrence of such suboptimal gene complexes may be attributable to effects of genetic drift in small, isolated populations.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Adaptação Biológica
/
Copépodes
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Evolution
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos