Plant & Animal Genome VII Conference

S5

PECULARITIES OF THE PINE GENOME

Faculty of Genetics, Departments of Forest Science and Crop Science, Texas A&M University, College Station, TX 77843-2135 USA

Pine genomics research is shaped by ecology, life history and genomic attributes. Genomics technology transfer from model flowering species may prove to be less efficient than exploiting gymnosperm attributes directly. Pines are part of the oldest unbroken seed plant lineage, with fossils dating back to 200 million years. It is surprising to find that pines share a levithan genome size (22-30 pg/C) and 12 pairs of chromosomes, both of which show negligible variation even among divergent subgenera. Preliminary evidence supports genic and possibly ancient genomic duplication. Pines are highly outcrossing plants; many species reveal a wealth of multiple alleles, high embryonic genetic loads and few barriers to interspecific hybridization. Perhaps the most interesting but least explored attribute is the pine genome itself. How are genes organized within the is complex genome? Although 70-80% of the pine genome is repetitive DNA, there is also a notable excess of low-copy DNA. Sequencing within low-copy DNA and in undermethylated regions reveals retroelements, certain classes of trinucleotide repeats, various regulatory elements as well as some conserved genic regions.