Are mitochondria inherited paternally in Ascaris?

Mitochondrial DNA (mtDNA) is finding increasing usage as a tool for studying the systematics, population genetics and epidemiology of parasitic helminths, and is generally assumed to be inherited maternally. Yet two features of Ascaris biology--fertilization by large amoeboid sperm and some novel aspects of sperm mitochondria--suggest a paternal component to mitochondrial inheritance in this organism. In this study, we compare mtDNA restriction patterns of parental worms with those of their progeny but find no evidence for paternal inheritance. We suggest that sperm-derived mitochondria are actively destroyed or outcompeted by maternal organelles in the zygote.