Leech anticoagulants are ancestral and likely to be multifunctional
Bibliographic record
Abstract
Abstract Bloodfeeding leeches have powerful anticoagulants that allow them to feed for extended periods. However, many leech species are predatory rather than bloodfeeding. It is not known whether they express these proteins and whether the proteins are co-opted for other purposes. Little is known about salivary secretions of the sister groups of leeches, where blood is not part of the diet. We screened the transcriptomes of four non-bloodfeeding leeches and four leech relatives to identify major lineages of anticoagulant genes, helping to determine their evolutionary origin and maintenance. We estimated selection regimes that are expected after a change in feeding behaviour. We found widespread presence of putative anticoagulants, although our results also indicate that several of these are members of multicopy gene families. Our analyses suggest that homologues to leech anticoagulants were already present before the origin of bloodfeeding in leeches and that negative selection is the major driver of evolutionary rates even in non-bloodfeeding taxa. These results point to the retention of the original function by these molecules in non-bloodfeeding species. Ultimately, the proteins might not be involved in bloodfeeding or it seems likely that their putative pleiotropic effects are of great importance.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".