Integrated and independent evolution of heteromorphic sperm types.
Proc Biol Sci
; 280(1769): 20131647, 2013 Oct 22.
Article
em En
| MEDLINE
| ID: mdl-24004938
ABSTRACT
Sperm are a simple cell type with few components, yet they exhibit tremendous between-species morphological variation in those components thought to reflect selection in different fertilization environments. However, within a species, sperm components are expected to be selected to be functionally integrated for optimal fertilization of eggs. Here, we take advantage of within-species variation in sperm form and function to test whether sperm components are functionally and genetically integrated both within and between sperm morphologies using a quantitative genetics approach. Drosophila pseudoobscura males produce two sperm types with different functions but which positively interact together in the same fertilization environment; the long eusperm fertilizes eggs and the short parasperm appear to protect eusperm from a hostile female reproductive tract. Our analysis found that all sperm traits were heritable, but short sperm components exhibited evolvabilities 10 times that of long sperm components. Genetic correlations indicated functional integration within, but not between, sperm morphs. These results suggest that sperm, despite sharing a common developmental process, can become developmentally and functionally non-integrated, evolving into separate modules with the potential for rapid and independent responses to selection.
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Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Espermatozoides
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Drosophila
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Evolução Biológica
Limite:
Animals
Idioma:
En
Revista:
Proc Biol Sci
Assunto da revista:
BIOLOGIA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Estados Unidos