DNA content and genome composition of diploid and triploid water frogs belonging to the <i>Rana</i> <i>esculenta</i> complex (Amphibia, Anura)
Bibliographic record
Abstract
The Central European water frog Rana esculenta L., 1758 is a natural hybrid between Rana lessonae Camerano, 1882 (LL) and Rana ridibunda Pallas, 1771 (RR). Hybrids are usually diploid (RL) or triploid (LLR or RRL). Distinguishing LL from RL, RR from RL, and LLR from RRL according to external morphology is ambiguous. In this study we checked whether the DNA content in erythrocyte nuclei measured by image cytometry is useful in determination of the taxonomic status of diploids (LL, RR, and RL) and the genome composition of triploids (LLR and RRL). For exact and direct identification of parental species, as well as for determination of genome composition in hybrids, we applied actinomycin D – 4',6-diamidino-2-phenylindole chromosome staining to metaphase plates. We analyzed 43 LL, 12 RR, and 32 RL diploids, and 37 LLR and 19 RRL triploids. All diploid hybrids had 2n = 26 chromosomes, and all triploid hybrids had 3n = 39 chromosomes. Neither aneuploid nor mosaic hybrids were detected. The expected numbers of 13 R. lessonae (L) and 13 R. ridibunda (R) chromosomes in RL hybrids were recorded in about 31% of individuals. In the rest of the sample the composition was variable, ranging from 9 to 14 R chromosomes and the corresponding number of L chromosomes. The expected composition of 26 L and 13 R chromosomes was detected in about 32% of LLR triploids, whereas in the rest of the sample the composition of chromosomes ranged from 8 to 15 R chromosomes and the corresponding number of L chromosomes. The expected numbers of 26 R and 13 L chromosomes were detected in about 26% of RRL triploids, whereas in the rest of the sample the composition of chromosomes ranged from 19 to 28 R chromosomes and the corresponding number of L chromosomes. The DNA content densitometry showed that RR and RL diploids had 9.5% and 3.8% more DNA, respectively, than LL diploids. These differences, although statistically significant, were not sufficient to unequivocally discriminate LL from RL and RR from RL. Triploids had about 50% more DNA than LL diploids (49% in LLR and 51% in RRL), but these differences were too small for unequivocal determination of their genome composition.
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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) | 0.001 | 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".