Background: Oil palm is the second largest source of edible oil which contributes to approximately 20% of the world's production of oils and fats. In order to understand the molecular biology involved in in vitro propagation, flowering, efficient utilization of nitrogen sources and root diseases, we have initiated an expressed sequence tag (EST) analysis on oil palm.

BackgroundGracilaria tenuistipitata is an agarophyte with substantial economic potential because of its high growth rate and tolerance to a wide range of environment factors. This red seaweed is intensively cultured in China for the production of agar and fodder for abalone. Microsatellite markers were developed from the chloroplast genome of G. tenuistipitata var. liui to differentiate G. tenuistipitata obtained from six different localities: four from Peninsular Malaysia, one from Thailand and one from Vietnam. Eighty G. tenuistipitata specimens were analyzed using eight simple sequence repeat (SSR) primer-pairs that we developed for polymerase chain reaction (PCR) amplification.FindingsFive mononucleotide primer-pairs and one trinucleotide primer-pair exhibited monomorphic alleles, whereas the other two primer-pairs separated the G. tenuistipitata specimens into two main clades. G. tenuistipitata from Thailand and Vietnam were grouped into one clade, and the populations from Batu Laut, Middle Banks and Kuah (Malaysia) were grouped into another clade. The combined dataset of these two primer-pairs separated G. tenuistipitata obtained from Kelantan, Malaysia from that obtained from other localities.ConclusionsBased on the variations in repeated nucleotides of microsatellite markers, our results suggested that the populations of G. tenuistipitata were distributed into two main geographical regions: (i) populations in the west coast of Peninsular Malaysia and (ii) populations facing the South China Sea. The correct identification of G. tenuistipitata strains with traits of high economic potential will be advantageous for the mass cultivation of seaweeds.

Sargassum is a source for many metabolites, including alginic acid, alginates, sulfated fucoidans, pigments, oils, sterols, and mannitols. The present study is the first attempt to examine Sargassum binderi (Sonder) J. Agardh, a tropical brown seaweed, using an expressed sequence tag (EST) approach. Singlepass 5¢ sequencing of 2304 cDNA clones generated 1876 ESTs of good quality, from which 1270 tentative unique genes (TUGs) consisting of 991 singletons and 279 contigs were obtained. Approximately 39.5% of the TUGs from S. binderi showed significant matches to the existing data bases and were further divided into nine subcategories: metabolism (24.9%); transcription and translation (22.5%); cellular processes (7.2%); protein folding, sorting, and degradation (5.6%); signaling (2.8%); membrane and transport (3%); receptor (1.1%); other functions (4.2%); and unknown proteins (28.7%). The sequences were compared with ESTs from Laminaria digitata (Hudson) J. V. Lamour.

Red seaweeds of the genus Gracilaria are agarophytes that produce more than 60% of the world's agar supply. Despite the importance of this genus in agar production, the potential of Gracilaria as a candidate for genomic research has been almost unexplored. In this study, a total of 8,088 expressed sequence tags (ESTs) were generated from Gracilaria changii, and clustered into 4922 tentative unique genes (TUGs), of which approximately 35% showed significant matches (bit scores greater than 50 and E-values less than 10 À5 ) to other genes in the databases. Among the TUGs that have significant similarity to the genes in the databases are ESTs corresponding to diverse functional groups such as metabolism, transcription, signalling, translation, transportation, protein folding, sorting, destination and degradation, cell division, cellular processes, replication and repair, cell structure, and miscellaneous. cDNAs involved in diverse metabolic pathways were identified among the EST collection. The presence and frequency of the transcripts allow us to survey the transcriptomic activities of this tropical agarophyte.

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