| บทคัดย่อ(English) |
The black tiger shrimp (~iPenaeus monodon~i) is an economically important organism for several countries in Asia and the Pacific, including Thailand, which is the worlds number one shrimp exporter. Exportation of frozen shrimp brings an annual income of two billion US dollars to Thailand. Outbreak of diseases is a major cause of shrimp mortality and economic losses. In order to gain a better understanding of the molecular basis of shrimp defense mechanisms, this study aims to obtain cDNA clones relevant to this function. In this study, we used RT-PCR and touch-down PCR to clone partial cDNA fragments from shrimp haemocytes, the major cell type involved in eliminating invading pathogens. In addition, degenerate primers were designed from a conserved Rel-coding domain of NF-(+,K)B sequences of humans, mice, and ~iD. melanogaster~i. This pair of primers was unsuccessful in amplifying a Relcoding domain sequence from shrimp. However, during cloning attempts, we found other shrimp cDNA sequences that showed highly conserved sequences related to known proteins of other eukaryotes including 14-3-3-like protein, Innexin, and (+,a)-tubulin. More than one type of each sequence was found. 14-3-3 protein is a known multifunctional protein with a marked role in signal transduction. Additionally, we found two clones that might be related to the immune response, namely clones for hemolectin and a thiolester-motif containing protein (complement-like protein) as well as other clones of uncertain identities. The results of this research suggest that the clones for hemolectin and the thiolester-motif containing protein be investigated further for their roles in the shrimp immunity. |
