Plant & Animal Genome IX Conference Plant & Animal Genome IX Conference
Poster: Forest Trees
P5i_19.html
The objective of this work is to compare genetic maps of two economically important conifer species in Europe: Pinus pinaster and Picea abies. Pinus taeda is used as a reference in a Conifer Comparative Genome Project (http://dendrome.ucdavis.edu/Synteny/index.html). Syntenic relationships between the three species were established with ESTPs (Expressed Sequence Tag Polymorphism) markers obtained from pine cDNA libraries. Two sets of 100 primers pairs (set1 and 2 available at http://www.pierroton.inra.fr/genetics/pinus/primers.html and http://dendrome.ucdavis.edu/Synteny/primerpairs.html) were designed to amplify preferentially PCR fragments in conserved or in more variable (3' UTR) coding regions, respectively. Length and Single Strand Conformation Polymorphisms (SSCP) were detected for set1 and Denaturant Gradient Gel Electrophoresis (DGGE) method was used to detect variation in set2.The PCR results showed that phylogenic distance between species (inter-Genus amplification is lower than intra-Genus amplification) and primers position (amplification in coding regions is higher than in 3' UTR) influence the amplification rates.25 and 40 EST were located in P.abies and P.pinaster maps respectively. Compared to P.taeda reference map, gene composition and order show a good conservation. Considering that karyotype did not change in most of the members of the Pinaceae family (2n=24), it is likely that the genome structure of conifers did not evolve a lot since their divergence. Thorough results are needed to validate this hypothesis.In addition to providing anchor points for comparative mapping, ESTP markers give direct access to expressed genes and should enable us to identify positional candidate genes (i.e. genes that map within a QTL interval) for important quantitative traits.