Evolutionary diversification of satellite DNA sequences from<i>Leymus</i>(Poaceae: Triticeae)
Bibliographic record
Abstract
The genus Leymus (lymegrass) comprises about 30 polyploid, perennial, temperate grass species in the tribe Triticeae (family Poaceae). Previous studies indicated a large diversity in the Leymus genome, and therefore, the aim of this study was to isolate new repetitive DNA sequences that can be used for differentiating Leymus species and elucidating their genomic relationships. A C0t-1 DNA plasmid library was generated from genomic DNA of American tetraploid species Leymus triticoides. A family of highly repetitive satellite DNA sequences, designated Lt1, was obtained from this library. The Lt1 family consisted of 380 bp SacI repeating units arranging in tandem arrays. A 120 bp MspI subfamily was discovered within this family, indicating that cytosine methylation may have played an important role in the evolution of satellite sequences. The Lt1 satellite was localized in the subtelomeric heterochromatic blocks of L. triticoides chromosomes, which are present on all chromosomes and often on both arms. The Lt1 sequences are abundant in L. triticoides but absent in its closely related species Leymus racemosus. Significant homology was found between the Lt1 family and numerous repetitive sequences from Poaceae species, indicating that the Lt1 is an ancient family of tandemly repeated sequences in grasses.
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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".