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 species) to be attractive to mate searching females, evidence that mating with males possessing such traits improves offspring survival and performance is scarce. In particular, there is a lack of unambiguous data linking preferred male traits with inherited genetic 'viability', which are essential for 'good genes' models of sexual selection. In this paper, we provide a protocol for performing half-sibling crosses in three-spined sticklebacks using a split-clutch in vitro fertilisation (SC-IVF) technique. This approach controls for variable maternal investment and standardises parental care - two confounding variables that frequently distort the relationship between sire trait and offspring performance - allowing the detection of offspring viability characteristics linked to specific sire traits such as sexual coloration, body size or condition.