Comparative mapping of a new repetitive DNA sequence and chromosome region-specific probes unveiling rearrangements in an Amazonian frog complex
Bibliographic record
Abstract
The frog species Physalaemus ephippifer exists in the Amazonian region and harbors heteromorphic Z and W chromosomes. A genetic lineage closely related to this species was recognized based on its mitochondrial DNA and RADseq-style markers, but its taxonomic status is still unclear and has been referred to as Lineage 1 of “P. cuvieri”. The heteromorphic sex chromosomes found in P. ephippifer are not present in this lineage and which of its chromosome pairs is homologous to the sex chromosomes of P. ephippifer remain to be elucidated as well as the role of such a karyotypic divergence in the evolution of these frogs. Here, we described a new family of repetitive DNA and used its chromosomal sites along with the markers detected by a probe constructed from the microdissected segment of the Z chromosome of P. ephippifer to infer chromosomal homology. We also analyzed an unnamed species that is considered to be the sister group of the clade composed of Lineage 1 of “P. cuvieri” and P. ephippifer. Our results suggest that complex rearrangements involving the chromosomes that were inferred to be homeologous to the sex chromosomes of P. ephippifer have occurred during the divergence of this group of frogs.
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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 | 0.001 | 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) | 0.002 | 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".