当前位置： SCI文献检索 > JOURNAL OF MOLECULAR EVOLUTION期刊下所有文献 > Analyses of ribosomal RNA sequences from glaucocystophyte cyanelles provide new insights into the evolutionary relationships of plastids.

Analyses of ribosomal RNA sequences from glaucocystophyte cyanelles provide new insights into the evolutionary relationships of plastids.

Abstract：

:Glaucocystophyte algae (sensu Kies, Berl. Deutsch. Bot. Ges. 92, 1979) contain plastids (cyanelles) that retain the peptidoglycan wall of the putative cyano-bacterial endosymbiont; this and other ultrastructural characters (e.g., unstacked thylakoids, phycobilisomes) have suggested that cyanelles are "primitive" plastids that may represent undeveloped associations between heterotrophic "host" cells (i.e., glaucocystophytes) and cyanobacteria. To test the monophyly of glaucocystophyte cyanelles and to determine their evolutionary relationship to other plastids, complete 16S ribosomal RNA sequences were determined for Cyanophora paradoxa, Glaucocystis nostochinearum, Glaucosphaera vacuolata, and Gloeochaete wittrockiana. Plastid rRNAs were analyzed with the maximum-likelihood, maximum-parsimony, and neighbor-joining methods. The phylogenetic analyses show that the cyanelles of C. paradoxa, G. nostochinearum, and G. wittrockiana form a distinct evolutionary lineage; these cyanelles presumably share a monophyletic origin. The rDNA sequence of G. vacuolata was positioned within the nongreen plastid lineage. This result is consistent with analyses of nuclear-encoded rRNAs that identify G. vacuolata as a rhodophyte and support is removal from the Glaucocystophyta. Results of a global search with the maximum-likelihood method suggest that cyanelles are the first divergence among all plastids; this result is consistent with a single loss of the peptidoglycan wall in plastids after the divergence of the cyanelles. User-defined tree analyses with the maximum-likelihood method indicate, however, that the position of the cyanelles is not stable within the rRNA phylogenies. Both maximum-parsimony and neighbor-joining analyses showed a close evolutionary relationship between cyanelles and non-green plastids; these phylogenetic methods were sensitive to inclusion/exclusion of the G. wittrockiana cyanelle sequence.(ABSTRACT TRUNCATED AT 250 WORDS)

journal_name

J Mol Evol

journal_title

Journal of molecular evolution

authors

Helmchen TA,Bhattacharya D,Melkonian M

doi

10.1007/BF00170674

subject

Has Abstract

pub_date

1995-08-01 00:00:00

pages

203-10

issue

eissn

0022-2844

issn

1432-1432

journal_volume

pub_type

杂志文章

在线工具

Analyses of ribosomal RNA sequences from glaucocystophyte cyanelles provide new insights into the evolutionary relationships of plastids.