Inheritance of mitochondrial DNA in the rotifer Brachionus plicatilis

By crossing Brachionus plicatilis s.s. NH1L strain and German strain, we obtained two types of hybrids, NH1L female × German male designated as NXG and German female × NH1L male designated as GXN. To confirm the crossing of the two hybrid strains at the genetic level, random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) analysis using 10 kinds of primers (10 and 12 mers) was carried out. Some amplified DNA fragments from RAPD of the hybrid strain showed mixed patterns of both parental strains, thus confirming that both hybrids were crossbreeds of the NH1L and German strains. Using these hybrids, we investigated the mode of mitochondrial inheritance in B. plicatilis. Full length mtDNA of the four strains was amplified by PCR, and digested with restriction enzymes to obtain restriction fragment length polymorphism (RFLP) patterns. Both hybrid strains had the same RFLP patterns as their female parents. This result shows that mitochondrial inheritance in rotifers is maternal