Characterization and genetic analysis of bovine α<sub>s1</sub>‐casein <i>I</i> variant
Bibliographic record
Abstract
The aim of this study was to identify the molecular genetic origin underlying the I variant of alpha(s1)-casein and to develop a DNA-based test for this polymorphism as a tool for genetic analyses independent of milk sample testing. All coding exons and flanking regions of the alpha(s1)-casein gene were sequenced in DNA samples from cattle of known alpha(s1)-casein genotypes (BI, CI, II, CC), determined by isoelectric focusing of milk samples. A nucleotide substitution (A>T) in exon 11 (g.19836A>T) leads to the exchange of Glu with Asp at amino acid position 84 of the mature protein (p.Glu84Asp) and perfectly co-segregated with the presence of the alpha(s1)-casein I variant in the milk of the analysed animals. Genotyping of a total of 680 DNA samples from 31 Bos taurus and Bos indicus cattle breeds and from Bos grunniens, Bison bison and Bison bonasus by restriction fragment length polymorphism analysis revealed the occurrence of Asp at position 84 at low frequencies in Bos taurus and Bos indicus breeds and established its origin from the alpha(s1)-casein C variant (p.Glu192Gly). Ten different intragenic haplotypes in the gene region from intron 8 to intron 12 were observed by sequencing, of which two occurred in Bison bison and one in Bison bonasus only. Using available casein gene complex information, an association of Asp at position 84 to beta-casein A(2) and kappa-casein B was shown in the Bos indicus breed Banyo Gudali. Taken together, we can postulate that the alpha(s1)-casein variant I is caused by a non-synonymous nucleotide substitution in exon 11 of the gene and that it originated within Bos indicus and spread to Bos taurus subsequently.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 |
| 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) | 0.000 | 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 teacher head, 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".