title: Exploration of salivary proteins in buffalo: an approach to find marker proteins for estrus.
abstract: Saliva is considered as the best source of biological material for biomarker discovery studies since it is noninvasive in comparison to other body sources. Usually buffalo cannot precisely express estrus signals. Hence, there is a need for concise methods to detect the time of estrus to ensure the success of artificial insemination. Therefore, we have established a reference proteome map on the whole saliva of buffalo during their estrous cycle with special reference to estrus. Nearly 12 bands have been observed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of whole saliva. Collectively, 179 proteins are identified with respect to different phases of the estrous cycle using mass spectrometry. On the whole, 37 proteins are exclusively expressed in the estrus phase, which include β-enolase, Toll-like receptor (TLR) 4, clusterin, lactoperoxidase, serotransferrin, TGM3, UBA6, and transducin. Among the proteins, β-enolase and TLR 4 were validated, and their specific expression was found during estrus as compared to other phases using immunoblot. The functional annotation reveals many as binding proteins in the estrus saliva when compared to the other phases. The present findings conclude that the proteomic approach adopted to identify the proteins from buffalo saliva around the estrous cycle may provide a new tool for screening the estrus phase. The results further conclude that the specific expression of β-enolase and TLR 4 can be taken as the indicator of estrus in buffalo.
authors.affiliation: Center for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India;
authors.forename: Subramanian
authors.initials: S
authors.lastname: Muthukumar
authors.affiliation: Institute of Medical Biology, A-STAR, Singapore;
authors.forename: Ramalingam
authors.initials: R
authors.lastname: Rajkumar
authors.affiliation: Center for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India;
authors.forename: Durairaj
authors.initials: D
authors.lastname: Rajesh
authors.affiliation: Center for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India;
authors.forename: Ganesan
authors.initials: G
authors.lastname: Saibaba
authors.affiliation: Proteomics Research Center, National Yang-Ming University, Taipei, Taiwan; and.
authors.forename: Chen-Chung
authors.initials: CC
authors.lastname: Liao
authors.affiliation: Center for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India; archunan@bdu.ac.in ppadmanabhan@ntu.edu.sg.
authors.forename: Govindaraju
authors.initials: G
authors.lastname: Archunan
authors.affiliation: Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore archunan@bdu.ac.in ppadmanabhan@ntu.edu.sg.
authors.forename: Parasuraman
authors.initials: P
authors.lastname: Padmanabhan
authors.affiliation: Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
authors.forename: Balazs
authors.initials: B
authors.lastname: Gulyas
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002020:Buffaloes; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D030762:Estrous Cycle / Q000378:metabolism*; D004971:Estrus / Q000378:metabolism*; D011237:Predictive Value of Tests; D020543:Proteome / Q000378:metabolism; D012463:Saliva / Q000737:chemistry*; D012471:Salivary Proteins and Peptides / Q000032:analysis*
chemical_list: D015415:Biomarkers; D020543:Proteome; D012471:Salivary Proteins and Peptides
keywords: LC-MS/MS; SDS-PAGE; estrous cycle; β-enolase