Figure 1. mtDNA content and sex of progeny of a female-biased mother crossed with a male of its own or of a different species.

A) Homospecific cross. All progeny, but two, were females and all carried only the mother's mtDNA. B) Hybrid cross. Sex distribution among progeny is different than in A (11 progeny females, 14 males and 5 hermaphrodites), yet all progeny carry only the mother's mtDNA, as in A.