51. Cloning and sequencing of mitochondrial encoded genes in rice

E. K. KALEIKAU, C. ANDRE, B. DOSHI and V. WALBOT

Department of Biological Sciences, Stanford University, Stanford, CA 94305, U.S.A.

Three mitochondrial encoded genes of IR36 rice-apocytochrome b (cob), subunit 3 of cytochrome c oxidase (coxIII), and subunit 9 of ATP synthase (atp9) -were isolated from a lambda library using maize probes and cloned into a Bluescript KS- plasmid vector. Southern hybridization analysis and restriction mapping indicate that two cob genes exist which differ in their 3' coding regions. Both cob genes have been cloned and partially sequenced. Interestingly, northern hybridization analysis detects only one major cob transcript suggesting that one of the cob genes might be a pseudogene. The coding regions for coxIII and atp9 have been sequenced and show 97% homology to maize sequences, however, both the 5' and 3' flanking sequences are divergent. The complete sequence of both cob rice genes, coxIII and atp9 will be published elsewhere.