Résumé
Tissue culture of oil palm induces somaclonal variation. The main one, known as the mantled abnormality, displays homeotic floral modifications and is associated with a lower oil yield. To detect abnormal cell lines as early as possible during the tissue culture process, studies to identify molecular markers have been carried out. Given the epigenetic nature of the mantled phenotype, differential gene expression has been focused upon rather than genome structure. We investigated gene expression patterns at the transcriptome level for three developmental stages: embryogenic cell suspensions, somatic embryos and leafy shoots. In the first step, the technique of subtractive PCR (SSH) was used to construct six cDNA libraries from variant and normal plant materials allowing enrichment for cDNA corresponding to genes which are up- or down-regulated in association with clonal conformity. In the second step, transcript abundance was monitored by macroarray hybridization. A range of genes altered in their expression in abnormal tissues has been identified and a number of which have been validated by RT-PCR. This approach will provide insights into the biological processes involved in the generation of the mantle phenotype and the identified markers should lead to the development of a clonal conformity test. (Résumé d'auteur)