Comparison between stearoyl‐CoA desaturase expression in milk somatic cells and in mammary tissue of lactating dairy cows

Abstract

Stearoyl-CoA desaturase (SCD) is an important enzyme in the bovine mammary gland, where it inserts a cis-double bond at the Δ9 position in a wide range of fatty acids. Investigating SCD expression in the bovine mammary gland generally requires invasive biopsy to obtain mammary tissue. The aim of this study was to evaluate the use of milk somatic cells as a non-invasive alternative to biopsy for measuring mammary SCD expression in dairy cows. Both milk somatic cells and mammary tissue were collected from 14 Holstein-Friesian cows and used for analysis of SCD expression by real-time PCR. The SCD5 mRNA levels in mammary tissue compared with SCD1 were low, and for several milk somatic cell samples, SCD5 expression was even below the limit of detection. A significant relationship was found between SCD1 expression in milk somatic cells and in mammary tissue. In addition, SCD1 expression in milk somatic cells was significantly related to Δ9-desaturase indices in milk, which are commonly used as an indicator of SCD1 activity within the mammary gland. Our study showed that milk somatic cells can be used as a source of mRNA to study SCD1 expression in dairy cows, offering a non-invasive alternative to mammary tissue samples obtained by biopsy.

Effects of short- and long-chain fatty acids on the expression of stearoyl-CoA desaturase and other lipogenic genes in bovine mammary epithelial cells

“…Notably, we previously demonstrated modest relationships between mRNA levels of SCD1 in biopsies of the bovine mammary gland and the C16 or C18 desaturation index (r 2 of 0.35 and 0.39, respectively; Jacobs et al, 2011), as calculated from total lipids extracted from the milk, whereas others reported that D9 desaturation indices were poor predictors of SCD activity (Bionaz and Loor, 2008;Invernizzi et al, 2010). Interestingly, the relationship between SCD1 expression in bovine milk somatic cells and the C16 or C18 desaturation index was somewhat better than the relationship between SCD1 expression in biopsies of mammary gland and these indices (Jacobs et al, 2013). We concluded that SCD1 mRNA expression in milk somatic cells could provide a better reflection of SCD1 activity in the mammary gland compared with the expression measured in bovine mammary tissue obtained from biopsy.…”

“…The primers selected for qPCR are presented in Supplementary Table S1. The primers to quantify bovine SCD1, ACTB, 18S RNA, peroxisome proliferator-activated receptor alpha (PPARA) and peroxisome proliferatoractivated receptor delta (PPARD) expression have been used previously (Jacobs et al, 2011;Goselink et al, 2013;Jacobs et al, 2013). PCR efficiencies for the genes were established to be at least 91%.…”

Screening for the Most Suitable Reference Genes for Gene Expression Studies in Equine Milk Somatic Cells

“…Moreover, numerous independent experiments revealed that milk somatic cells (MSC) may be considered as a source of valuable material for gene expression studies, which may reflects the transcriptional potential of the lactating mammary gland [ 1 – 3 ]. It is particularly important for the investigations focused on searching for molecular markers associated with milk composition, as well as studies regarding molecular aspects of immunological response during mammary gland inflammation [ 4 , 5 ]. As it was indicated by Cánovas et al (2014) [ 2 ] in comparison to the other sources (e.g.…”

Differential expression of CXCR1 and commonly used reference genes in bovine milk somatic cells following experimental intramammary challenge

“…Compared to biopsies, milk somatic cells allow for easy resampling but yield less RNA, especially if the SCC is low [ 19 ]. Because of the low yield in some samples, we opted to isolate RNA from all milk somatic cells rather than a subpopulation (e.g.…”