The regulation of fruit ripening at molecular level is poorly understood in nonclimateric fruit such as the strawberry. The accumulation of anthocyanin is a visible and easily measured change in ripening strawberry fruit. This accumulation of anthocyanin is accompanied by increases in the activities of two enzymes which form part of the anthocyanin biosynthetic pathway: phenylalanine ammonia-lyase (PAL) and uridine diphosphate glucose: flavonoid 03-glucosyltransferase (UDPGFT). The aim of this project is the molecular cloning and functional characterization of genes that are involved in the regulation of the genes of the anthocyanin biosynthetic pathway (Myb transcriptional factors). With this purpose a turning stage cDNA expression library and a substractive cDNA library (ripe stage vs unripe stage) will be screened with to differents oligos nucleotide probes. One of them is a general oligo corresponding to the consensus sequence of the Myb DNA binding domain. It would be able to clone putative Myb transcriptional factors related to the strawberry ripening process. And the other oligo corresponds to the DNA binding sequence of the an2 gene, a petunia homologuos of the Cl gene of maize, that has been shown to be involved in the control of a set of structural anthocyanin genes in the limb of the petal from petunia flowers. Such studies would permit a better knowledge of the color generation pathways and their application through biotechnology to improve the colors of fruit of agronomical and economical relevance. It will also show whether Myb transcriptional factors are involved in other ripening process differents in addition to their role in the production of colour.