NUCLEAR-ENCODED PROTEIN-CODING GENES OF THE AGAROPHYTE GRACILARIA-VERRUCOSA (GRACILARIALES, RHODOPHYTA)

Single-copy nuclear genes encoding cytosolic glyceraldehyde-3-phosphat e dehydrogenase (GapC), triosephosphate isomerase (TPII) and polyubiqu itin (UBI6R), plastid-localized GAPDH (GapA), and mitochondrial aconit ase (m-ACN), together with their corresponding cDNAs, have been cloned or PCR-amplified from Gracilaria verrucosa, sequenced, and characteri zed by genomic Southern hybridization. Three spliceosomal introns were found, one each near the 5' end of GapA, GapC, and m-ACN. Codon usage is biased, with third-position A's underrepresented. Nucleotide compo sitions of the genes are balanced except in TPII. Upstream promoter st ructure, downstream poly(A) processing signals, intron splice junction s, and one translation initiation site were analyzed. Poly(A) processi ng features of these red algal genes resemble those of green plants mo re than those of animals.