Function and evolution of a minimal plastid genome from a nonphotosynthetic parasitic plant. Export

@article{citeulike:5419264, abstract = {Complete nucleotide sequencing shows that the plastid genome of Epifagus virginiana, a nonphotosynthetic parasitic flowering plant, lacks all genes for photosynthesis and chlororespiration found in chloroplast genomes of green plants. The 70,028-base-pair genome contains only 42 genes, at least 38 of which specify components of the gene-expression apparatus of the plastid. Moreover, all chloroplast-encoded RNA polymerase genes and many tRNA and ribosomal protein genes have been lost. Since the genome is functional, nuclear gene products must compensate for some gene losses by means of previously unsuspected import mechanisms that may operate in all plastids. At least one of the four unassigned protein genes in Epifagus plastid DNA must have a nongenetic and nonbioenergetic function and, thereby, serve as the reason for the maintenance of an active genome. Many small insertions in the Epifagus plastid genome create tandem duplications and presumably arose by slippage mispairing during DNA replication. The extensive reduction in genome size in Epifagus reflects an intensification of the same processes of length mutation that govern the amount of noncoding DNA in chloroplast genomes. Remarkably, this massive pruning occurred with a virtual absence of gene order change.}, author = {Wolfe, K. H. and Morden, C. W. and Palmer, J. D.}, citeulike-article-id = {5419264}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/1332054}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=1332054}, day = {15}, issn = {0027-8424}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, keywords = {monotropa, plastid}, month = {November}, number = {22}, pages = {10648--10652}, posted-at = {2009-08-11 23:29:47}, priority = {2}, title = {Function and evolution of a minimal plastid genome from a nonphotosynthetic parasitic plant.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/1332054}, volume = {89}, year = {1992} }

TY - JOUR ID - citeulike:5419264 L3 - citeulike-article-id:5419264 N2 - Complete nucleotide sequencing shows that the plastid genome of Epifagus virginiana, a nonphotosynthetic parasitic flowering plant, lacks all genes for photosynthesis and chlororespiration found in chloroplast genomes of green plants. The 70,028-base-pair genome contains only 42 genes, at least 38 of which specify components of the gene-expression apparatus of the plastid. Moreover, all chloroplast-encoded RNA polymerase genes and many tRNA and ribosomal protein genes have been lost. Since the genome is functional, nuclear gene products must compensate for some gene losses by means of previously unsuspected import mechanisms that may operate in all plastids. At least one of the four unassigned protein genes in Epifagus plastid DNA must have a nongenetic and nonbioenergetic function and, thereby, serve as the reason for the maintenance of an active genome. Many small insertions in the Epifagus plastid genome create tandem duplications and presumably arose by slippage mispairing during DNA replication. The extensive reduction in genome size in Epifagus reflects an intensification of the same processes of length mutation that govern the amount of noncoding DNA in chloroplast genomes. Remarkably, this massive pruning occurred with a virtual absence of gene order change. IS - 22 JF - Proceedings of the National Academy of Sciences of the United States of America SN - 0027-8424 EP - 10652 TI - Function and evolution of a minimal plastid genome from a nonphotosynthetic parasitic plant. VL - 89 SP - 10648 KW - monotropa KW - plastid AU - Wolfe, KH AU - Morden, CW AU - Palmer, JD PY - 1992/11/15/ UR - http://view.ncbi.nlm.nih.gov/pubmed/1332054 ER -