Abstract

In this study, forward and reverse suppression subtractive hybridization (SSH) libraries were constructed between female and male gametophyte of Gracilaria lemaneiformis to isolate genes differentially expressed between gametophytes. Dot-blots were performed to screen 384 colonies randomly selected from each subtracted libraries. Partial gene (designated as GMF-01) which is female gametophyte-specific was selected to isolate its cDNA full length sequences and to be characterized. Then we got its cDNA full length sequences using SMART-RACE technic. Sequence analysis showed that the open reading frame (ORF) of GMF-01 is 1002 bp long with a GC content of 47.7%, encoding 333 amino acids. GMF-01 does not have significant match in the databases when examined on NCBI website. Amino acid sequence analysis showed that the theoretical pI of this translated protein is 7.92, while the instability index is computed to be 43.61, which has classified the protein as unstable. Results of prediction showed 45.05% of its secondary structure has random coil and sub-cellular location prediction indicated that it is probably a extracellular protein.

Key words: Gracilaria lemaneiformis, suppression subtractive hybridization (SSH), sex determination, gametophyte.