Identification of serum protein markers for early diagnosis of pregnancy in buffalo

Improper or delayed pregnancy diagnosis has significant impact over animal production, particularly in buffaloes which inherently suffer from several reproductive inefficiencies. Thus the present study has undertaken to identify serum protein markers pertaining to early pregnancy diagnosis in buffaloes. Serum samples were collected from 10 pregnant Murrah Buffalo heifers at weekly intervals from days 0‐35 post‐artificial insemination and from 12 inseminated non‐pregnant cyclic buffalo heifers on days 0, 7, 14 and 21. Two‐dimensional gel electrophoresis and densitometric analysis revealed the presence of five protein spots showing average density fold change of ≥4 during early pregnancy. Mass spectrometry analysis identified these up‐regulated proteins as anti‐testosterone antibody light chain, apolipoprotein A‐II precursor, serum amyloid A, cytokeratin type II, component IV isoform 1, which are have established roles in embryogenesis, but over‐expression of the fifth identified protein immunoglobulin lambda light chain in pregnancy has been elucidated as a novel finding in the current study. Further, with bioinformatics analysis, potential antigenic B‐cell epitopes were predicted for all these five proteins. An antibody cocktail‐based approach involving antibodies against all these five up‐regulated entire proteins or their epitopes could be developed for early detection of pregnancy in buffaloes. © 2016 Japanese Society of Animal Science