2 TRANSCRIPTOME ANALYSIS OF GRANULOSA CELLS FROM GROWING DOMINANT FOLLICLE REVEALS AGE-ASSOCIATED CHANGES AT THE TIME OF FOLLICLE SELECTION IN AGED BEEF CATTLE
Bibliographic record
Abstract
Growing dominant follicles at the time of selection from aged (n = 3; 15 ± 1.5 years) and young (n = 3; 6 ± 1.1 years) Hereford cows were compared using bovine-specific microarrays containing 40 000 targets. The objective of the study was to determine age-associated changes in transcriptome of granulosa cells at the time of dominant follicle selection. Cows were given prostaglandin F2a to cause ovulation (Day 0) and granulosa cells from dominant follicles were collected on Day 3 either by ultrasound-guided follicle aspiration or after ovariectomy. The mRNA was extracted, analyzed for quality, converted into antisense RNA, amplified, labelled with red and green florescent dyes, and hybridized with microarrays. Feature intensities were measured using Array-Pro software (Media Cybernetics Inc., Rockville, MD), and differentially expressed genes were obtained using FlexArray 1.6. A total of 169 transcripts were differentially expressed with a fold change of =2 (P = 0.05) in aged cows v. young cows. Ingenuity System Pathway (IPA; Ingenuity Systems Inc., Redwood City, CA) analysis of these transcripts revealed that granulosa cells of aged cows exhibit (1) reduced capability to regulate gonadotropins [?follistatin (FST), ?inhibin beta A (INHBA), ?inhibin beta B (INHBB)] and reduced responsiveness to gonadotropin-induced changes in cytoskeleton [?tropomyosin 2 (TPM2), ?actin gamma 2 (ACTG2), ?tubulin beta] and extracellular matrix [?tumor necrosis factor alpha-induced protein 6 (TNFAIP6), ?versican (VCAN)], (2) inefficiency in processing lipids [?low-density lipoprotein receptor (LDLR), ?stearoyl-coenzyme A desaturase (SCD), ?cluster of differentiation 36 (CD36), ?sterol-C4-methyl oxidase-like (SC4MOL)] and synthesizing steroids [?cytochrome P450, family 19, subfamily A, polypeptide 1 (CYP19A1), ?cytochrome P450, family 51, subfamily A, polypeptide 1 (CYP51A1)], (3) decreased proliferation [?proliferating cell nuclear antigen (PCNA)] and control of cell cycle check points [?checkpoint kinase 1 (CHEK1), ?centromere-associated protein E (CENPE)] and have poor intercellular communication [?gap junction protein alpha 1 (GJA1)], and (4) higher expression of oxidative stress responsive genes [?vanin-1 (VNN1), ?vanin-2 (VNN2), and ?glutathione peroxidase 3 (GPX3)]. A total of 6 transcripts: CYP19A1 (aromatase; P = 0.1), VNN1 (P = 0.05), INHBA (P = 0.1), PCNA (P = 0.001), TPM2 (P = 0.1), and GJA1 (P = 0.05) were selected to validate the microarray results via quantitative real-time PCR. In conclusion, granulosa cells of growing dominant follicles exhibit age-related changes in the transcriptome at the time of selection relative to young cows; changes that may explain follicle-associated loss of oocyte competence in aged cows. Research was supported by the Natural Sciences and Engineering Research Council of Canada (Ottawa, ON, Canada).
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) | 0.001 | 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".