Identification of a novel sperm class and its role in fertilization in <i>Drosophila</i>
Bibliographic record
Abstract
In many species, males have evolved to produce a sterile sperm (parasperm) in conjunction with fertilizing sperm (eusperm). Here, we document evidence of males depositing two morphologically distinct types of parasperm (1 and 2) into the female reproductive tract in Drosophila pseudoobscura. These parasperm differ in length, shape, amount produced, amount in long-term storage and may have separate roles in ensuring male fertilization success. Although both parasperm types protect eusperm from female spermicides, only parasperm 2, which has a corkscrew shape, is associated with sperm competition. Increased production of parasperm 2 is also negatively correlated with the eusperm and parasperm 1 production. Thus, selection may be acting on parasperm production in the presence of sperm competition. Our findings show how both sperm competition and cryptic female choice may be acting in conjunction to influence the evolution of ejaculate composition. Our identification and characterization of two distinct parasperm morphs will enhance the ability for further evaluation of parasperm's role in fertilization.
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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 | 0.000 | 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".