مشخصات پژوهش

Compone nts of male semina l flui ds are known to stimulate fec undity and fertilit y in females of numerous insect species and paternal effects on offspring phenotyp e are also known, but no studies have yet demonstrated links between male effec ts on female reproduction and tho se on progen y pheno type. In separate laboratory experi ments emp loying 10-day-old virgin females of Cheilomenes sexm aculata(F.), we varied male age and mating history to manipu late levels of male allo mones and found that the magnitud e of paternal effects on progen y phenotyp e was correlated with stimulation of female reproduction. Older virgin males remained in copula longer than younger ones, induced higher levels of female fecundi ty, and sired proge ny that developed faster to yield heavier adul ts. When male age was held constant (13 days), egg fertili ty de clined as a function of previ ous male copulations, proge ny develop mental times increased, and the adult weight of daughters decline d. These results sug gest that male epigene tic effects on progeny pheno type act in concert with female reproductive stimulation; both categories of effects increased as a conseq uence of male celibacy ( facto r accumulation), and dim inished as a function of previ ous matings ( factor depletio n). Male facto rs that influence female reproduc tion are implicated in sexual conflict an d parental effects may extend this conflic t to offspring pheno type. Whereas mothers control the timin g of oviposition events and can use maternal effect s to tailor progeny phenot ypes to prevaili ng or anticip ated conditions, fathers canno t. Since females remate and dilu te paternit y in polyandrous systems, paternal fitne ss wil l be increased by link ing paternal effect s to female fecundi ty stimulation, so that more benefit s accrue to the male ’s own progeny.