Caprine CSN1S1 haplotype effect on gene expression and milk composition measured by Fourier transform infrared spectroscopy
Journal : Journal of Dairy Science (JDS) , vol. 93 , p. 4340–4350–11 , 2010
Publisher : Elsevier
International Standard Numbers
Printed : 0022-0302
Electronic : 1525-3198
Publication type : Academic article
Issue : 9
OMTALE : http://dx.doi.org/10.3168/jds....
DOI : doi.org/10.3168/jds.2009-2854
If you have questions about the publication, you may contact Nofima’s Chief Librarian.
The Norwegian dairy goat population has a high frequency of a CSN1S1 (alpha(S1)-casein) haplotype with negative effects on protein and fat content. It is characterized by a single point deletion in exon 12 of CSN1S1, leading to a truncated protein and hence a low content of alpha(S1)-casein in the milk. This haplotype together with another haplotype with a deletion in exon 9 are called "weak" haplotypes. "Strong" haplotypes, on the other hand, have positive effects on important milk production traits. We show that expression of CSN1S1 in the mammary gland of lactating goats is significantly lower in animals with 2 weak haplotypes. Moreover, the effects of defective alleles were not detected in animals having 1 strong and 1 weak haplotype. Expression levels of other genes in the casein cluster were not affected by the CSN1S1 haplotypes investigated. Milk samples from goats with 2 weak haplotypes could be distinguished from the other milk samples using Fourier transform infrared (FTIR) spectroscopy and partial least squares discriminant analysis (PLS-DA). The PLS-DA components were related to spectra of pure caseins and whey proteins, hence FTIR has a potential for identifying milk samples with low alpha(S1)-casein content and different protein composition. The results indicate that FTIR-based measurements can be incorporated into breeding plans, or for selection of milk samples with high casein content, which in turn may improve cheese-making properties of the milk.