A 6374 unigene set corresponding to low abundance transcripts expressed following fertilization in Solanum chacoense Bitt, and characterization of 30 receptor-like kinases.
Institut de Recherche en Biologie Végétale (IRBV). Département de sciences biologiques, Université de Montréal, 4101 Sherbrooke Est, H1X 2B2, Montréal, QC, Canada.
In order to characterize regulatory genes that are expressed in ovule tissues after fertilization we have undertaken an EST sequencing project in Solanum chacoense, a self-incompatible wild potato species. Two cDNA libraries made from ovule tissues covering embryo development from zygote to late torpedo-stage were constructed and plated at high density on nylon membranes. To decrease EST redundancy and enrich for transcripts corresponding to weakly expressed genes a self-probe subtraction method was used to select the colonies harboring the genes to be sequenced. 7741 good sequences were obtained and, from these, 6374 unigenes were isolated. Thus, the self-probe subtraction resulted in a strong enrichment in singletons, a decrease in the number of clones per contigs, and concomitantly, an enrichment in the total number of unigenes obtained (82%). To gain insights into signal transduction events occurring during embryo development all the receptor-like kinases (or protein receptor kinases) were analyzed by quantitative real-time RT-PCR. Interestingly, 28 out of the 30 RLK isolated were predominantly expressed in ovary tissues or young developing fruits, and 23 were transcriptionaly induced following fertilization. Thus, the self-probe subtraction did not select for genes weakly expressed in the target tissue while being highly expressed elsewhere in the plant. Of the receptor-like kinases (RLK) genes isolated, the leucine-rich repeat (LRR) family of RLK was by far the most represented with 25 members covering 11 LRR classes.
Plant Mol. Biol. 2005;59(3):515-32.
Pubmed ID: 16235114