Differential gene expression and analysis of milk proteins from dairy buffalo with and without subclinical mastitis

Author(s)

Fernanda Tanamati

• Document type: Doctoral Thesis
• Press: Jaboticabal. 2018-03-22.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2018-02-27
• Advisor: Humberto Tonhati; Nedenia Bonvino Stafuzza; Daniele Fernanda Gimenez

Abstract

Mastitis in dairy buffalo causes economic losses due to decreased milk production, along with having a negative effect on the animals’ welfare. Thus, two studies were performed: the objective of study I was to evaluate the expression levels of lactoferrin (LTF), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin- 8 (IL-8) and toll-like receptors 2 (TLR-2) and 4 (TLR-4) in Murrah buffaloes with and without subclinical mastitis. Milk samples were collected from 12 buffaloes with mastitis and 12 buffaloes without mastitis for RNA extraction, cDNA synthesis, and validation of expression profiles by qRT-PCR. The ΔΔCt was estimated using orthogonal contrasts of the target genes expression adjusted for the expression of the housekeeping genes between both treatments. The expression of the TLR-2, TLR-4, TNF-α, IL-1β and IL-8 genes were upregulated in buffaloes with mastitis, while the LTF gene showed no differential expression. The study of these immune function genes that are active in the mammary gland is important for the development of strategies aimed at preserving the health of the udder. The objective of study II was to evaluate the proteins present in the milk whey from buffaloes with and without subclinical mastitis, using a proteomic approach to identify differentially expressed proteins and potential biomarkers for the disease. For this, 16 samples of Murrah buffalo milk were collected, comprised of eight animals with and eight animals without subclinical mastitis. The spectral counting method was used to quantify the relative abundance of the individual proteins, and the databases of proteins annotated for Bubalus bubalis and for Bos taurus were used in the analysis. After integrating the gene annotations from the buffalo and bovine references, a total of 1,033 proteins were identified, of which 156 proteins were differentially regulated between healthy and affected animals. 18 biological processes in which these proteins participate were identified, and cathelicidin-3 was identified as a potential biomarker of subclinical mastitis. These results are important to better understand the behavior of mastitis in the buffalo mammary gland, and in turn may aid in the early diagnosis. (AU)

• FAPESP's process: 14/19321-4 - Study of the expression of genes related to mastitis in dairy buffaloes
• Grantee: Fernanda Tanamati
• Support Opportunities: Scholarships in Brazil - Doctorate