Chromosomal and molecular perspectives on <i>Potamotrygon motoro</i> (Müller & Henle, 1841) from central Amazon
Bibliographic record
Abstract
Cytogenetic studies on Potamotrygon motoro (Müller & Henle, 1841) are limited to classical cytogenetic techniques, but they do reveal great karyotypic variation. The main differences are related to the karyotypic formula and the absence/presence of sex chromosome systems. Thus, this study aimed to expand knowledge of the karyotypic composition of Potamotrygon motoro from different locations of the Central Amazon using Fluorescence in situ Hybridization to investigate the distribution of ribosomal DNAs (rDNA) and microsatellites sequences (SSRs). In addition, we used the mitochondrial DNA cytochrome oxidase subunit I (mtDNA COI) to perform neighbor-joining analysis to investigate the relationships among the individuals sampled. In our study, Potamotrygon motoro presented 2n = 66 chromosomes, with 18m + 12sm + 10st + 26a and heterochromatic blocks on centromeric region of all chromosomes. The 18S rDNA is present in three chromosomal pairs and 5S rDNA is located in the pair 16, which is a feature shared among freshwater stingray species. Regarding the mapping of SSRs, dinucleotide sequences showed a greater number of sites, usually on terminal regions of chromosomal pairs, with an accumulation throughout the long arms of the pair 17. Our molecular analyses did not reveal differences between the sequences used. In general, the karyotypic differences previously reported for Potamotrygon motoro indicate the presence of different cytotypes within the species.
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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 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".