Gene discovery in the finger leather coral Sinularia notanda by construction and sequencing of a normalized cDNA library.

The transplantation of coral fragments is one of methods that restore coral communities. To form coral colonies, the fragmented corals initiated skeletal extension from the cut-edge of fragment then success the settlement. In order to understand the molecular events underlying fragment adhesion and settlement, we constructed a normalized cDNA library and generated and annotated expressed sequence tags (ESTs) from the fragmented adult polyps of soft coral Sinularia notanda. We generated 3251 high-quality ESTs with an average length of 580 bp and the EST cluster and assembly analyses produced 2796 unigenes, including 2487 singletons and 309 contigs. Of the known genes, 55 genes were sel ected to be involved in polyp fragment adhesion and settlement based on Gene Ontology (GO) classification. Notably, two EST clones were identified to show homology with galaxin gene which was demonstrated as coral specific calcifying protein of organic matrix. These EST sequences can provide utility as molecular markers in molecular and genetic studies of S. notanda and other soft coral.

Additional duplicated Hox genes in the earthworm: Perionyx excavatus Hox genes consist of eleven paralog groups.

Annelida is a lophotrochozoan phylum whose members have a high degree of diversity in body plan morphology, reproductive strategies and ecological niches among others. Of the two traditional classes pertaining to the phylum Annelida (Polychaete and Clitellata), the structure and function of the Hox genes has not been clearly defined within the Oligochaeta class. Using a PCR-based survey, we were able to identify five new Hox genes from the earthworm Perionyx excavatus: a Hox3 gene (Pex-Hox3b), two Dfd genes (Pex-Lox6 and Pex-Lox18), and two posterior genes (Pex-post1 and -post2a). Our result suggests that the eleven earthworm Hox genes contain at least four paralog groups (PG) that have duplicated. We found the clitellates-diagnostic signature residues and annelid signature motif. Also, we show by semi-quantitative RT-PCR that duplicated Hox gene orthologs are differentially expressed in six different anterior-posterior body regions. These results provide essential data for comparative evolution of the Hox cluster within the Annelida.

Population genetic structure of the ark shell Scapharca broughtonii Schrenck from Korea, China, and Russia based on COI gene sequences.

Haplotype distribution, gene flow, and population genetic structure of the ark shell (Scapharca broughtonii) were studied using a partial sequence of a mitochondrial COI gene. The sequence analysis of 100 specimens obtained from a total of seven localities-five in Korea, one in China, and one in Russia- revealed 29 haplotypes, ranging in sequence divergence from 0.1% to 2.1%. Among these, the most frequent haplotype, SB16, was extensively distributed over study areas, especially in all Korean localities. This extensive distribution consequently resulted in the near absence of statistically significant genetic distance. Also, a high rate of gene flow was characteristic among localities in Korea. A test of genetic population structure showed that the ark shell in Korea formed a large genetic group. Moreover, an AMOVA test to determine the allocation of the genetic variance showed that most of the variance was distributed between localities, instead of within localities. However, a significant population differentiation was found between geographic populations [i.e., Jinhae (locality 6) in Korea and Sangdong (locality 5) in China and Vladivostok (locality 7) in Russia] based on geographic distance and population structure. These distinct groups may be associated with geographic characteristics and barriers. The results suggest that most of the ark shell populations in Korea caused considerable distribution to form a genetically homogeneous and intermixing structure, whereas some of the Korean and Chinese and Russian populations had a significantly different genetic structure.