Demystifying the functions of the mitochondrial ORFan proteins in bivalves with doubly uniparental inheritance
Bibliographic record
Abstract
Strict maternal inheritance of mitochondria is known to be the rule in animals, but over 100 species across six orders of bivalves possess doubly uniparental inheritance (DUI) of mitochondria. Under DUI, two distinctive sex-specific mitogenomes coexist. In marine and freshwater mussels, each mitogenome has an additional protein-coding gene, called female- and male-specific open reading frame or forf and morf , respectively. The function(s) of the associated FORF and MORF proteins remain unknown. Herein, we show that these proteins present similar tissue expression patterns in two distantly related DUI species: MORF was only expressed in male gonads, whereas FORF was expressed in all tissues of both sexes in the marine mussel Mytilus edulis and the freshwater mussel Venustaconcha ellipsiformis . Moreover, MORF was only expressed during the reproductive season, while FORF presented no clear seasonality pattern in M. edulis . Immunocytochemistry revealed the presence of both proteins in mitochondria and acrosomes of late spermatids and mature sperm. We hypothesize that MORF has a key function in spermatogenesis, while FORF has a more general function in both sexes. We also propose that both proteins may be involved in the fertilization process. The involvement of MORF in paternal mitochondrial transmission is also discussed.
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) | 0.000 | 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".