| Popis: |
The green alga Chlamydomonas reinhardtii is an ideal model in which to study the cooperation of nuclear and chloroplast genes in chloroplast ribosome biogenesis. At least six of the 33 r-proteins identified in the large subunit and 14 of the 31 r-proteins of the small subunit appear to be made in the chloroplast of C. reinhardtii, with the remainder being synthesized in the cytoplasm (Schmidt et al, 1983). Antibodies to 16 chloroplast r-proteins from C. reinhardtii have been examined for cross reactivity with specific r-proteins from Anabaena, E. coli and the chloroplast of spinach (Randolph-Anderson et al, 1989; Schmidt et al, 1984). To date 11 chloroplast-encoded r-protein genes have been identified in C. reinhardtii (Harris, 1992). The completely sequenced chloroplast genomes of tobacco, rice and the liverwort Marchantia have revealed an additional 12 r-protein genes which have not yet been located in Chlamydomonas (Shimada and Sugiura, 1991). With a few exceptions, the same set of r-protein genes is found in all chloroplast genomes examined in green algae and land plants (Palmer, 1991). The exceptions include the location of the rpl5 gene in the chloroplast genome of Chlamydomonas and certain other algae, the rpl21 gene in the chloroplast genome of Marchantia, and the rpsl6 gene in the chloroplast genome of higher plants but not in Marchantia. |
