Split-clutch IVF: A technique to examine indirect fitness consequences of mate preferences in sticklebacks

Although laboratory mate choice experiments and field studies often reveal certain traits of male three-spined sticklebacks (as well as other model sp ecies) to be attractive to mate searching females, evidence that mating wit h males possessing such traits improves offspring survival and performance is scarce. In particular, there is a lack of unambiguous data linking prefe rred male traits with inherited genetic 'viability', which are essential fo r 'good genes' models of sexual selection. In this paper, we provide a prot ocol for performing half-sibling crosses in three-spined sticklebacks using a split-clutch in vitro fertilisation (SC-IVF) technique. This approach co ntrols for variable maternal investment and standardises parental care - tw o confounding variables that frequently distort the relationship between si re trait and offspring performance - allowing the detection of offspring vi ability characteristics linked to specific sire traits such as sexual color ation, body size or condition.