Metabolomic Profiles of Bovine Mammary Epithelial Cells Stimulated by Lipopolysaccharide.

Bovine mammary epithelial cells (bMECs) are the main cells of the dairy cow mammary gland. In addition to their role in milk production, they are effector cells of mammary immunity. However, there is little information about changes in metabolites of bMECs when stimulated by lipopolysaccharide (LPS). This study describes a metabolomics analysis of the LPS-stimulated bMECs to provide a basis for the identification of potential diagnostic screening biomarkers and possible treatments for bovine mammary gland inflammation. In the present study, bMECs were challenged with 500 ng/mL LPS and samples were taken at 0 h, 12 h and 24 h post stimulation. Metabolic changes were investigated using high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF MS) with univariate and multivariate statistical analyses. Clustering and metabolic pathway changes were established by MetaboAnalyst. Sixty-three differential metabolites were identified, including glycerophosphocholine, glycerol-3-phosphate, L-carnitine, L-aspartate, glutathione, prostaglandin G2, α-linolenic acid and linoleic acid. They were mainly involved in eight pathways, including D-glutamine and D-glutamic acid metabolism; linoleic acid metabolism; α-linolenic metabolism; and phospholipid metabolism. The results suggest that bMECs are able to regulate pro-inflammatory, anti-inflammatory, antioxidation and energy-producing related metabolites through lipid, antioxidation and energy metabolism in response to inflammatory stimuli.

CRISPR/Cas9 genome editing technique and its application in site-directed genome modification of animals.

CRISPR/Cas system, which uses CRISPR RNAs (crRNAs) to guide Cas nuclease to silence invading nucleic acids, is self-defense system against exogenous virus or plasmid in bacteria and archaea. Through molecular modification, the typeⅡCRISPR/Cas system has become a highly efficient site-directed genome editing technique, which is simpler than zinc-finger nucleases (ZFNs) and transcription activator like effector nucleases (TALENs) and easier to be designed and applied. In this review, we summarize the evolutionary history of CRISPR/Cas9 system, the working principle and modification process of type Ⅱ CRISPR/Cas and its application in animal genome modification. We also analyze the existing problems and improvement program of the CRISPR/Cas9 system as well as its application prospect combined with successful cases, which may provide innovative perspectives on improving animal traits and establishing animal models of human diseases.