Sperm proteome of apyrene and eupyrene sperm in Carolina Sphinx moth Manduca sexta, and monarch butterfly Danaus plexippus

All but the most basal Lepidopteran species produce two sperm morphs. Only one of these morphs is capable of completing karyogamy and producing offspring, this morph contains the correct genetic complement and is termed eupyrene sperm. Apyrene sperm, on the other hand, is completely devoid of nuclear DNA and fertilisation incompetent. Despite the fact apyrene sperm is believed to be functional, the function of this sperm type is largely unknown. Here we apply tandem mass spectrometry based proteomics to the two sperm types independently in the monarch butterfly (Danaus plexippus) and the carolina sphinx moth (Manduca sexta). Comparative analysis between sperm morphs and species shows a reduced complexity and greater divergence in apyrene sperm relative to eupyrene consistent across the two species.