Expanded male sex-determining region conserved during the evolution of homothallism in the green alga Volvox
Bibliographic record
Abstract
Male and female genotypes in heterothallic (self-incompatible) species of haploid organisms, such as algae and bryophytes, are generally determined by male and female sex-determining regions (SDRs) in the sex chromosomes. To resolve the molecular genetic basis for the evolution of homothallic (bisexual and self-compatible) species from a heterothallic ancestor, we compared whole-genome data from Thai and Japanese genotypes within the homothallic green alga Volvox africanus . The Thai and Japanese algae harbored expanded ancestral male and female SDRs of ∼1 Mbp each, representing a direct heterothallic ancestor. Therefore, the expanded male and female ancestral SDRs may originate from the ancient (∼75 mya) heterothallic ancestor, and either might have been conserved during the evolution of each homothallic genotype. An expanded SDR-like region seems essential for homothallic sexual reproduction in V. africanus , irrespective of male or female origin. Our study stimulates future studies to elucidate the biological significance of such expanded genomic regions.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 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".