Isolation and unique composition of purified head plasma membrane from rooster sperm
Bibliographic record
Abstract
The structure, composition, and function of membranes from organelles of mammalian spermatozoa differ from each other and from the sperm's plasma membrane. Avian sperm studies have suffered from the lack of a technique to isolate these various membranes, which the current study now provides. Nitrogen cavitation and differential centrifugation separated head plasma membranes (HPM) of rooster sperm from sperm debris, acrosomal membranes, and mitochondrial membranes and characterized these membranes enzymatically and microscopically. The HPM was enriched in acid phosphatase (marker enzyme for HPM; 1,814.81 +/- 470.43 micromol phosphate released/microg protein vs. 868.53 +/- 75.55 for whole semen; a 202.5 +/- 37.8% enrichment, mean +/- SE, P < 0.001), with less (P < 0.001) mitochondrial and acrosomal enzyme activity. The mitochondrial fraction had 515.1 +/- 167.6% more succinate dehydrogenase activity (marker for mitochondria, P < 0.001) and the acrosomal fraction had 315.4 +/- 61.2% more acetylglucosaminidase activity (marker for acrosome, P < 0.0001) than whole semen. Thin layer and gas chromatography showed that HPM lipids had more (P < 0.05) sphingomyelin and phosphatidylserine, and less phosphatidylcholine and phosphatidylethanolamine than did the sperm body membranes (SBM). Overall, HPM had less polyunsaturated fatty acids than SBM (36.8 +/- 3.4 vs. 44.5 +/- 1.7% of total phospholipids, P < 0.05). HPM had slightly more n3 (3.2 +/- 0.5 vs. 1.3 +/- 0.2%, P < 0.01) but much less n6 (33.6 +/- 3.3 vs. 43.3 +/- 1.9%, P < 0.01), specifically less C22:4n6. Future study of avian sperm will be able to reliably characterize the structure-function relationships of specific sperm membranes.
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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 | 0.001 |
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".