ISSN:
1432-0983
Keywords:
Sorghum
;
Mitochondrial DNA
;
orf25
;
Cytoplasmic male sterility
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We describe fundamental characteristics of sorghum mitochondrial orf25,urf209, and a related chimeric configuration,orf265/130, which is restricted to the IS1112C source of cytoplasmic male sterility in sorghum. Transcripts ofurf209 are edited at ten nucleotides, resulting in nine amino-acid changes predicted from genomic sequences. The eDNA-predicted polypeptide product is 23.6 kDa, while Western blot analyses identify a product of 20 kDa. Transcription ofurf209 is characterized by one or two transcripts, dependent on nuclear background, but this difference is not related to male fertility status. Theorf265/130 chimeric region includes 288 by 95% identical to sequences 5′ to maize T-cytoplasmT-urf13 andatp6, which includes a common transcription initiation site, and terminates with a recombinational event involvingurf209. Theurf209 similarity extends 189 bp, followed by sequences duplicated 5′ to sorghumatp6-2. Sequences immediately 3′ to theatp6-2 similarity include a second inframe start codon, definingorf130. Structural features 5′ toorf130 are shared with motifs found 5′ to several translated mitochondrial open reading frames. Theorf265/orf130 configuration is uniquely transcribed, and transcripts oforf130 exhibit one silent RNA editing event. Transcription in somatic cells is not altered by male fertility status.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02221557
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