The Catalytic Function of Hormone-Sensitive Lipase is Essential for Fertility in Male Mice
Bibliographic record
Abstract
In male mice, deficiency of hormone sensitive lipase (HSL, Lipe gene, E.C.3.1.1.3) causes deficient spermatogenesis, azoospermia, and infertility. Postmeiotic germ cells express a specific HSL isoform that includes a 313 amino acid N-terminus encoded by a testis-specific exon (exon T1). The remainder of testicular HSL is identical to adipocyte HSL. The amino acid sequence of the testis-specific exon is poorly conserved, showing only a 46% amino acid identity with orthologous human and rat sequences, compared with 87% over the remainder of the HSL coding sequence, providing no evidence in favor of a vital functional role for the testis-specific N-terminus of HSL. However, exon T1 is important for Lipe transcription; in mouse testicular mRNA, we identified 3 major Lipe transcription start sites, finding numerous testicular transcription factor binding motifs upstream of the transcription start site. We directly explored two possible mechanisms for the infertility of HSL-deficient mice, using mice that expressed mutant HSL transgenes only in postmeiotic germ cells on a HSL-deficient background. One transgene expressed human HSL lacking enzyme activity but containing the testis-specific N-terminus (HSL-/-muttg mice). The other transgene expressed catalytically inactive HSL with the testis-specific N-terminal peptide (HSL-/-atg mice). HSL-/-muttg mice were infertile, with abnormal histology of the seminiferous epithelium and absence of spermatozoa in the epididymal lumen. In contrast, HSL-/-atg mice had normal fertility and normal testicular morphology. In conclusion, whereas the catalytic function of HSL is necessary for spermatogenesis in mice, the presence of the N-terminal testis-specific fragment is not essential.
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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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.002 |
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".