Reduced genetic variation of an Onchocerca volvulus ABC transporter gene following treatment with ivermectin
Bibliographic record
Abstract
In some trichostrongyloid nematodes, the early stages of ivermectin (IVM) resistance have been characterized by a shift in allele frequency and reduced polymorphism at loci of P-glycoprotein genes, glutamate-gated chloride channel genes and gamma-aminobutyric acid receptor genes. Mass treatment with IVM is an integral component of the onchocerciasis control programmes. Genetic variation of an Onchocerca volvulus ABC transporter homologue (OvABC-3) from several populations in Africa was examined to determine whether an association exists between alleles of this gene and IVM treatment. Allelic variation in a non-treated population from Ghana showed this locus to be highly polymorphic. However, variability was reduced in IVM-treated populations. chi2 analysis of polymorph frequencies showed significant differences between untreated and treated samples collected in Ghana in 1999. There was less variability in this gene in samples collected in 2002 compared with the 1999 samples. In some treated populations, there appeared to be selection on OvABC-3-C. The observed reduction in variability could be expected in a control programme in which prevalence and intensity of infections are markedly reduced after years of vector control and IVM distribution. The reduction in polymorphism may not in itself indicate that these O. volvulus are IVM resistant, although it could indicate that selection for resistance is occurring.
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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 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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 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".