Ultrastructural description of fresh and frozen/thawed sperm derived from collared peccaries (<scp><i>Pecari tajacu</i></scp> Linnaeus, 1,758)
Bibliographic record
Abstract
The aim was to describe, through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the ultrastructure of peccaries' fresh and frozen-thawed sperm. For that, semen derived from three mature males was obtained by electroejaculation and evaluated for motility, membrane integrity, membrane functionality, chromatin integrity, and morphology through light microscopy. Samples were frozen using a Tris extender plus egg yolk (20%) and glycerol (6%). Then, fresh and frozen-thawed semen samples were mixed in different sperm pools that were processed for SEM and TEM. Sperm motility, membrane integrity, and functionality were impaired (p < .05) by freezing-thawing procedures, but sperm morphology, and chromatin integrity evaluated by light microscopy were not significantly affected. The SEM revealed that peccaries' sperm presents a flattened head in a paddle format, measuring 6.07 μm in length and 3.84 μm in width, with a vastus acrosome (4.46 μm). Normal tails measure 38.11 μm, being formed by an extensive midpiece with 15.52 μm in length. In frozen-thawed samples, both SEM and TEM provide us information about damage undetected through light microscopy as the presence of vesicles in the acrosome, loose plasma membrane, vacuolized mitochondria, dense fibers disorganized, and decondensed chromatin. In conclusion, we provide the first description of the sperm ultrasctruture in collared peccaries. Moreover, SEM and TEM help us to identify some nanometric damage provoked by freezing-thawing procedures, thus providing valuable information for the improvement of such important protocols used for biobanking formation.
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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".