DOYLE, JEFF J.1*, JANE L. DOYLE1, JASON T. RAUSCHER1, and Tony (A. H. D.) Brown2. 1L. H. Bailey Hortorium, Department of Plant Biology, Cornell University, Ithaca, NY 14853 USA; 2Centre for Plant Biodiversity Research, CSIRO Plant Industry, GPO Box 1600, Canberra ACT 2601, Australia. - "New" nuclear genes and phylogenetic studies in Glycine.
Cytochrome oxidase subunit 2 (cox2) is a mitochondrial gene
that has been transferred to the nucleus in some legumes, and lost
from the mitochondrial genomes of some of these taxa. The nuclear copy
has acquired a spliceosomal intron that is approximately 1 kb long in
Glycine and allied genera. The nuclear copy of the gene is
duplicated in Glycine species; this is also the case with the
chloroplast-expressed nuclear gene for glutamine synthetase (ncpGS).
These two low copy nuclear genes join histone H3-D and the nrDNA ITS
region in providing useful characters for addressing a variety of
questions in Glycine and relatives. These include the origins
of the paleopolyploid genus, Glycine, relationships among
diploid species of Glycine subgenus Glycine, and the
origins and evolution of polyploids in the subgenus.
Key words: cytochrome oxidase subunit 2, glutamine synthetase, Glycine, polyploidy