Egg chemoattractants moderate intra specific competition- Lymberry, Kennigton Flashcards
what are egg and sperm interactions assumed to generate?
infraspecific variation in reproductive fitness
what is sperm chemotaxis and what is it a form of?
attraction sperm by egg derived chemicals
form of gamete signalling
what was used to track the success of sperms competing to fertilise the egg?
what evidence was provided?
fluorescently labelled mitochondrial dye in muscles
evidence thar competitive fertilisation success is moderated by differential sperm chemotaxis
what does the data support about egg chemoattractants selectivity ?
selectively attract ejaculates from genetically compatible males- inferred from mitochondrial and nuclear genetic markers
what does multiple mating lead to competition among?
among ejaculations for fertilisation
what does different sperm chemotaxis allow females to do?
to bias outcomes of intraspecific sperm competitions
base the bias on complex patterns of genetic compatibility
where did sexual selection began, what used to be the mechanism and what has this ancestral sexual selection given rise to?
in the sea
broadcast spawning
given rise to sexual dimorphism and internal fertilisation
what can studying gamete level interactions be applied to?
a wide range of taxonomic groups
what can eggs of broadcast spawners moderate?
recognition and fusion of sperm at gamete surface or select specific sperm nuclei
in the mussel what was revealed about chemoattractants?
that they have differential effects on swimming behaviour and physiology of sperm
what has important fitness implications?
intrasepcific effects of chemoattractants on fertilisation
what was being tested in M.galloprovincialis?
whether differential sperm chemotaxis/chemoattractants moderate gamete level mate choice and if fertilisation biases reflect patterns of genetic compatibility
what was used to label sperm mitochondria?
fluorescent dye
in mussels what mitochondria is inherited?
both male and female
what does differential attraction of sperm up an egg chemoattractant gradient moderate?
moderates intraspecific competitive fertilisation success
what do fertilisation biases reflect?
preferences for unrelated males at nuclear loci and selection of the same mitochondrial DNA lineage
what is M.Galloprovincialis?
sessile bivalve mollusc in intertidal regions in australia
in the methods which sperm competed?
sperm from each focal male and sperm from standard rival male with chemoattractant gradient from the female
in each cross what was used to assess competitive fertilisation success of focal male?
eggs from standard female
what did removal of male effect and male female interactions result in?
a worse fit than removal of male by female interaction alone
what did male by female interaction indicators show?
significant variation in the way chemoattractants of female affected competitive success (the success depended on the chemoattractants)
did nuclear genetic relatedness differ between focal male and female pairs?
no
when was competitive fertilisation success higher?
when focal male and female nuclear genotypes were less related and with the same mitochondrial lineage
what can differential attraction of sperm up a chemical gradient act as?
a mechanism of gamete level mate choice
what doe egg chemoattractants influence?
intraspecific sperm competition
what does chemotaxis ensure for broadcast spawners?
that egg is found and fertilised by conspecific sperm
