ACCESS TO THE SPRUCE GENOME ORGANIZATION AND EVOLUTION VIA INTEGRATED GENETIC MAPS

¹ Chaire de recherche du Canada en génomique forestière et environnementale, Université Laval, Sainte-Foy (Québec), Canada G1K 7P4

² Canadian Forest Service - Natural Resources Canada, Sainte-Foy (Québec), Canada G1V 4C7

In species with large and essentially unsequenced genomes, one aspect of comparative genomics is to evaluate the synteny between genetic maps of different species and get a comprehensive view of their genome organization. To do so, numerous anchor markers are necessary, which can recognize unambiguously homeologous chromosomic regions between species. Expressed sequence tag polymorphisms (ESTP) represent such anchor markers of orthologous gene loci. We have recently developed over a hundred of these markers for the comparative mapping of both Picea glauca (Moench) Voss and P. mariana (Mill.) B.S.P., two evolutionary distant species in the genus Picea. In order to maximize the number of positioned orthologous loci for genome comparison between species, at least two pedigrees with one parent in common for each of P. glauca and P. mariana were used for the construction of genetic maps. On average, more than 600 AFLP markers, 30 microsatellites, and 50 ESTPs have been positioned onto integrated genetic maps for each species. The marker density is ranging from 2.5 to 3 cM, spanning approximately 1500cM to 1700cM. The use of two pedigrees for each species resulted in 50% additional anchor markers useful for interspecific comparisons. Up to eight anchor markers per major linkage group have been positioned. Synteny and macro-colinearity were observed between species. These integrated genetic maps will help our understanding of genome architecture in conifers and furthermore, aid in identifying colinear chromosome segments involved in adaptive and economical traits.