Molecular characterization of ribosomal intergenic spacer in the tadpole shrimp<i>Triops cancriformis</i>(Crustacea, Branchiopoda, Notostraca)
Bibliographic record
Abstract
Nuclear ribosomal DNA constitutes a multigene family, with tandemly arranged units linked by an intergenic spacer (IGS), which contains initiation/termination transcription signals and usually tandemly arranged subrepeats. The structure and variability of the IGS region are analyzed here in hermaphroditic and parthenogenetic populations of the "living fossil" Triops cancriformis (Branchiopoda, Notostraca). The results indicate the presence of concerted evolution at the population level for this G+C-rich IGS region as a whole, with the major amount of genetic variability found outside the subrepeat region. The subrepeats region is composed of 3 complete repeats (a, c, d) intermingled with 3 repeat fragments (b, e, f) and unrelated sequences. The most striking datum is the absolute identity of subrepeats (except type d) occupying the same position in different individuals/populations. A putative promoter sequence is present upstream of the 18S rRNA gene, but not in subrepeats, which is at variance with other arthropod IGSs. The absence of a promoter sequence in the subrepeats and subrepeat sequence conservation suggests that this region acts as an enhancer simply by its repetitive nature, as observed in some vertebrates. The putative external transcribed spacer (840 bp) shows hairpin structures, as in yeasts, protozoans, Drosophila, and vertebrates.
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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) | 0.000 | 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".