The assessment of insemination success in yellow dung flies using competitive PCR
Autor: | Matthew Hall, Andrew J Pemberton, Paul I. Ward, Luc F. Bussière, Marco Demont |
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Rok vydání: | 2010 |
Předmět: |
Genetics
biology urogenital system cryptic choice Diptera DNA quantification biology.organism_classification Insemination Sperm sperm competition Sperm displacement Female sperm storage Spermatheca Evolutionary biology Sexual selection mate choice paternity sperm selection Scathophaga stercoraria Sperm competition Diptera - Evolution reproductive and urinary physiology Ecology Evolution Behavior and Systematics Biotechnology |
Zdroj: | Molecular Ecology Resources. 10:292-303 |
ISSN: | 1755-0998 1755-098X |
DOI: | 10.1111/j.1755-0998.2009.02754.x |
Popis: | In spite of considerable interest in postcopulatory sexual selection, separating the effects of sperm competition from cryptic female choice remains difficult because mechanisms underlying postcopulatory processes are poorly understood. One methodological challenge is to quantify insemination success for individual males within the sperm stores of multiply mated females to discover how insemination translates into eventual paternity. Any proposed method must be applicable in organisms without extensive DNA sequence information (which include the majority of model species for sexual selection). Here, we describe the development and application of microsatellite competitive-multiplex-PCR for quantifying relative contributions to a small number of sperm in storage. We studied how DNA template characteristics affect PCR amplification of known concentrations of mixed DNA and generated regressions for correcting observations of allelic signal strength based on such characteristics. We used these methods to examine patterns of sperm storage in twice-mated female yellow dung flies, Scathophaga stercoraria. We confirm previous findings supporting sperm displacement and demonstrate that average paternity for the last mate accords with the mean proportion of sperm stored. We further find consistent skew in storage across spermathecae, with more last male sperm stored in the singlet spermatheca on one side of the body than in the doublet on the opposite side. We also show that the time between copulations may be important for effectively sorting sperm. Finally, we demonstrate that male size may influence the opportunity for sperm choice, suggesting future work to disentangle the roles of male competition and cryptic female choice. |
Databáze: | OpenAIRE |
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