Molecular Cloning and Expression Analysis of Endogenous Cellulase EsGH9-1 from Eriocheir sinensis and Its Response to Different Diets
Bibliographic record
Abstract
Cellulases are a class of modular enzymes with a catalytic glycoside hydrolase (GH) module that hydrolyzes the β-1, 4-glucosidic bond of the cellulose chain. Cellulases had been broadly divided into three types: endo-β-1, 4-glucanases, exo-β-1, 4-glucanases and β-glucosidases, which of synergistic effect lead to the complete degradation of cellulose to glucose. The endo-β-1, 4-glucanase is one of the key cellulases in cellulose digestion, which are likely to be the product of a glycosyl hydrolase family 9 (GHF9) gene. In this study, an endogenous cellulase gene, EsGH9-1, was identified from the transcriptome database of the Chinese mitten crab, Eriocheir sinensis, and the sequence of EsGH9-1 was cloned by PCR. The expression levels of EsGH9-1 in different tissues and different developmental stages were studied. In addition, EsGH9-1 mRNA expression and corresponding enzyme activity under different diet conditions were analysed. The result showed that EsGH9-1 genomic DNA (11 679 bp) consists of 15 exons interrupted by 14 introns; EsGH9-1 cDNA (2044 bp) contains an open reading frame of 1740 bp, corresponding to a polypeptide of 580 amino acid residues, with a typical catalytic domain of the glycosyl hydrolase family 9 (GHF9). EsGH9-1 was expressed in various tissues of E. sinensis, particularly high in the hepatopancreas. A significant increase in expression of EsGH9-1 was also observed in megalopa and early-stage larvae. Under different dietary conditions, the relative expression of EsGH9-1 in the plant diet group was significantly up-regulated, which was consistent with the trend of β-1, 4-endoglucanase activity. The finding of the endogenous cellulase gene (EsGH9-1) in E. sinensis implies that EsGH9-1 may be involved in the decomposition of plant diet. Furthermore, this work is a fundamental step toward understanding the role of endogenous cellulase in the digestion mechanism of aquatic crustaceans.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".