Cytogenetic characterization by in situ hybridization techniques and molecular analysis of 5S rRNA genes of the European hazelnut (<i>Corylus avellana</i>)
Bibliographic record
Abstract
The European hazelnut (Corylus avellana L.) is widespread in Europe, where it has been cultivated for centuries. Despite progress in genetics, most of the cytogenetic aspects of this species have been overlooked. The aim of this study was to fill in this gap and obtain basic information on the chromosome structure of this species. Karyomorphological analysis confirmed the chromosome number 2n = 22 and showed that, despite their apparent uniformity, the chromosomes could be separated into three groups of different size: large (L), medium (M), and small (S). As a first step towards the physical mapping of the hazelnut chromosomes, we applied FISH to localize the position of rRNA genes (rDNA). The sites of 45S and 5S rDNA enabled us to identify two chromosome pairs belonging, respectively, to the L and S groups. The self-GISH procedure revealed that repetitive DNA is concentrated in the pericentromeric regions of the chromosomes, as with other species with rather small genomes. The analysis of 5S rDNA repeats offered additional information on the hazelnut genome by obtaining the whole sequence of the transcribed region so far unpublished. The overall results constitute a substantial advance in hazelnut cytogenetics. Further investigation of other species of Corylus could be an effective approach to understanding the phylogenesis of the genus and resolving taxonomic problems.
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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".