Glutamine synthetase as a biological marker for fish phylogenetics : some new insights
Bibliographic record
Abstract
Glutamine synthetase is a key enzyme for nitrogen metabolism. It occurs in all organisms and is one of the oldest functioning genes. Many vertebrates have only one functional copy of this gene, while many plants have been shown to be multicopy for this gene. Pseudogenes for glutamine synthetase have also been reported in mammals. Until recently only a single copy of glutamine synthetase had been described in fish. However, six copies of this gene are expressed in rainbow trout Oncorhynchus myklss and two copies of this gene are expressed in the gulf toadfish Opsanus beta. We investigated a variety of intertidal fishes from British Columbia, Canada using PCR amplification of genomic DNA product and reverse transcriptase PCR to explore the diversity of glutamine synthetase in fish. We recovered two isoforms of glutamine synthetase in fourteen out of twenty-one fish. We describe the partial sequences for the two copies of this gene that differed in nucleotide composition by 8 to 22 percent. Phylogenetic analysis was performed using the different glutamine synthetase isoforms to generate trees for intertidal fishes collected in this study. Fish from the following orders were represented in this study: Myxiniformes, Lepisosteiformes, Salmoniformes, Gasterosteiformes, Syngnathiformes, Scorpaeniformes, Perciformes and Pleuronectiformes. Most species adhered to the traditional taxonomic classification although some representative fish did not.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 source (direct Gemma or distilled Codex), 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".