Digital gene expression analyses of mammary glands from meat ewes naturally infected with clinical mastitis

Abstract

Clinical mastitis in sheep has gravely restrained production performance for a long time. Knowledge of mechanisms of its pathogenesis and resistance in meat sheep mammary gland with clinical mastitis are not yet understood, especially for clinical mastitis caused by natural infection. In this work, RNA-sequencing was firstly used to screen the differentially expressed genes (DEGs) in clinical mastitic mammary tissues (CMMTs) when compared with healthy mammary tissues (HMTs) from meat sheep flocks. We identified 420 DEGs including 316 upregulated and 104 downregulated genes in CMMTs. Gene ontology annotation revealed these DEGs were mainly engaged in immune response and inflammation response. Pathway enrichment showed they were primarily enriched in pathways relevant to inflammation, immune response and metabolism. Alternative splicing analysis showed most common differential splicing genes in CMMTs and HMTs were implicated in immune response. Immunostaining for three immune response-related proteins encoded by DEGs were mainly observed in mammary epithelium from both CMMTs and HMTs, and their positive signals were more intensive in CMMTs than those in HMTs. These findings provide experimental basis and reference for further researching the molecular genetic mechanisms, particularly immune defence mechanisms, of sheep mammary gland during clinical mastitis.

Mammary Defences and Immunity against Mastitis in Sheep

“…In any case, selection for mastitis resistance based on decreased somatic cell counts has been shown to be of value in selection of individuals with reduced susceptibility to mastitis [118,119,120]. A recent study has indicated that genes differentially expressed in mammary tissues of ewes with clinical mastitis, were involved with regulation of the immune response and the inflammation procedure in these animals [121]; this finding directly associates genetic background of ewes with mammary defences.…”

SLC34A2 Targets in Calcium/Phosphorus Homeostasis of Mammary Gland and Involvement in Development of Clinical Mastitis in Dairy Cows

“…Conjoint analysis revealed that the 12 shared DEPs were involved in ion homeostasis and absorption. Previous studies have shown that DEPs, such as SLC34A2 [30,31], PRKCB [32], FTH1 [1], and MAPK1 [33], could be putative biomarkers for mastitis. The PPI network displayed 12 candidate DEPs interacting with all selected GO terms, pathways, and DEPs, especially SLC34A2, indicating that these DEPs participate in the regulation of Ca/P metabolism and homeostasis via different routes.…”

Genome‐wide scan for selective sweeps identifies novel loci associated with resistance to mastitis in German Holstein cattle

“…Furthermore, some other genes such as RASGRP3 on chromosome 11 are involved in immune system mechanisms, cytokine signalling and B‐cell receptor signalling (Li et al, 2019; Parker Gaddis et al, 2018), CFAP69, STEAP2, ITGB3BP (chromosome 4) are related to immune system mechanisms and stimulate apoptosis in breast cancer cells (Gomes et al, 2012; van Roosmalen et al, 2015; Yang et al, 2017), FAM98A (chromosome 11) has a partial role in the organization of stress granules (Ozeki et al, 2019), which is a factor in tumour proliferation (Zheng et al, 2018).…”