碩士 / 國立臺灣海洋大學 / 水產養殖學系 / 97 / The full length sequence of α2-macroglobulin (α2-M) cDNA of longlegged spiny lobster Panulirus longipes (Palo) is 4583 bp with a 21 bp 5`UTR, a 191 bp 3`UTR and a 4371 bp open reading frame (ORF) which encodes 1457 amino acid containing a 22 aa signal peptide. The predicted molecular mass of the translated protein is 160.9 kDa with an estimated pI of 5.33. Palo α2-M is a glycoprotein with 9 putative N-link glycosylation sites that are located in the first 1/3 near N terminus and the area near thioester domain. The Palo α2-M has 3 functional domains: (1) a bait region with high variation in amino acids sequence, (2) a thioester domain (GEGEQNM), and (3) a receptor binding domain (RBD).
Based on the phylogenetic tree, α2-Ms are divided into vertebrate and invertebrate sub-groups. Invertebrate α2-Ms can be further divided into three groups, mollusc, insect and crustacean. Similarity analysis indicated that Palo α2-M showed respective similarity of 89.4%, 63.1%, 62.6%, 61.9%, 61.8%, 45.7 and 42.8 to Paho α2-M, Maro α2-M, Liva α2-M, Pemo α2-M, Maja α2-M, Scse α2-M, and Lipo α2-M, respectively.
Based on the phylogenetic tree, proPO are divided into insect and crustacean sub-group. Crustacean proPO can be further divided into 1) Malacostraca proPO (including crab, lobster and penaeid shrimp), and 2) Branchiopoda proPO (including artemia and daphnia). Similarity analysis indicated that Palo proPO showed similarity of 74.6% to Homarus americanus (Hoam) proPO. Palo proPO showed similarity of 70.1 ± 3.1％, 50.9 ± 1.7％ and 50.1 ± 0.9％ to Malacostraca proPO, Insecta proPO and Branchiopoda proPO, respectively.
Real-time quantitative RT-PCR indicated that α2-M and proPO only expressed in haemocyte, but not in hepatopancrease, intestine, muscle, gill and eyestalk.
Palo α2-M expression was significantly up-regulated at 24 h post β-glucan injection, whereas the Palo α2-M activity significantly decreased at 72 h post β-glucan injection. Palo proPO expression significantly up- regulated at 120 h post β-glucan injection, whereas the Palo α2-M activity significantly increased at 48 h post β-glucan injection. These facts indicated that the α2-M and proPO of lobster are induced by β-glucan.
| Identifer | oai:union.ndltd.org:TW/097NTOU5086013 |
| Date | January 2009 |
| Creators | Chien-Lun Huang, 黃千倫 |
| Contributors | Jiann-Chu Chen, 陳建初 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 99 |
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