FIG 1.

UPI of mitochondria occurs in Phycomyces. (A) Positions of the oligonucleotide primers used to amplify a variable part of the mitochondrial genome. (B) Agarose gel showing the sizes of the PCR products of an mtDNA fragment cut with TaqαI restriction enzyme from the parental strains. (C) Gels of the PCR products of the mtDNA fragment cut with TaqαI, from parents and five representative progeny from eight crosses (Table 1). (D) The mitochondria are inherited from the (+) parent regardless of the origin of the mitochondria. Agarose gels show the mtDNA fragment cut with TaqαI from the strains in which the mitochondrial genome was switched into the other sex background. (E) The mtDNA from the (−) parent is degraded in the zygospore. Chromatograms of a fragment of the mitochondrial genome amplified from the parents NRRL1554 (+) and NRRL1555 (−) and two single zygospores (one week old). The asterisks show the nucleotide sequences that differ between the parents. A trace of the mtDNA from the (−) parent is still amplified from zygospore 1.