Poster: Posttranscriptional Regulation

Abs # 1079: Characterization of nuclear encoded proteins required for chloroplast translation initiation in Chlamydomonas reinhardtii

Presenter:	Somanchi, Aravind , somanar@auburn.edu
Authors	Somanchi, Aravind  (A)
Affiliations:	(A): Auburn University

Nuclear encoded proteins have been shown to be required for the translation of several chloroplast mRNAs. Insertional mutagenesis has been an invaluable approach in the identification and characterization of several Chlamydomonas reinhardtii nuclear encoded proteins. A library of insertional mutants showing deficiencies in the synthesis of different photosynthetic proteins has been generated. Preliminary analyses have identified several of these mutants to have deficiencies in the synthesis of photosynthetic proteins, despite accumulating wt levels of corresponding mRNAs. Two such mutants, 1407 and 1428, have been shown to deficient in the accumulation of the chloroplast D1 and D2 proteins. Marker mapping and genome walking have been used to identify the insertion site of the marker and the sequences flanking the insertion. The flanking sequences are used to screen an indexed cosmid library to identify cosmids containing the wt copies of the genes, disrupted in the two mutants. The availability of the sequence of the complete nuclear genome of Chlamydomonas reinhardtii, will assist in the identification potential genes (and ORFs) present on these cosmids. Complementation of the mutants with the full-length cosmids and parts of the cosmid containing putative genes will facilitate the identification and characterization of the genes responsible for the mutant phenotypes.