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 ␤-enolase, Toll-like receptor (TLR) 4, clusterin, lactoperoxidase, serotransferrin, TGM3, UBA6, and transducin. Among the proteins, ␤-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 ␤-enolase and TLR 4 can be taken as the indicator of estrus in buffalo.-Muthukumar, S., Rajkumar, R., Rajesh, D

A comparison of the uterine proteome of mares in oestrus and dioestrus

“…In addition to its role as an APP, TF also has antibacterial properties: Through binding iron, TF contributes to decreasing iron available to micro‐organisms (Jurado, ). One study mapped the proteome of whole saliva throughout the oestrous cycle of buffalo, in which serotransferrin was noted to be one of the proteins exclusively expressed in the oestrus stage (Muthukumar et al, ). These characteristics suggest a rationale for the increased quantity of APOA1 and TF seen in the present study.…”

Evaluation of pheromone‐based kit: A noninvasive approach of estrus detection in buffalo

“…The urine samples were collected from buffaloes ( n = 36) maintained in the Post‐Graduate Institute of Research in Animal Science, Kattupakkam, Chennai, Tamil Nadu, India. The samples were categorized as proestrus (−3 day), estrus (day 0) and diestrus (+10) according to Rajanarayanan and Archunan (), and Muthukumar, Rajkumar, Rajesh, et al (). All the experimental procedures were approved by the Institutional Animal Ethics Committee (IAEC), Post‐Graduate Institute of Research in Animal Science, Kattupakkam, Chennai, Tamil Nadu, India.…”

“…The urine samples were collected from buffaloes (n = 36) maintained in the Post-Graduate Institute of Research in Animal Science, Kattupakkam, Chennai, Tamil Nadu, India. The samples were categorized as proestrus (−3 day), estrus (day 0) and diestrus (+10) according to Archunan (2011), andMuthukumar, Rajkumar, Rajesh, et al (2014). All the experimental procedures were…”

“…In the light of this, the success rate of AI is only approximately 50% or even less at the field level, which is a cause of concern leading to great economic loss. Several attempts have been made to devise methods to detect estrus in buffalo, but none has been proved as efficient or reliable (Muthukumar, Rajkumar, Karthikeyan, et al, ; Muthukumar, Rajkumar, Rajesh, et al, ; Rajanarayanan & Archunan, ). As farmers face real difficulty in successfully conducting AI in buffalo, there is an urgent need to develop a practicable noninvasive, farmer‐friendly method/kit/module to detect the estrus in buffalo which would enhance the success rate of AI.…”

“…Several attempts have been made to devise methods to detect estrus in buffalo, but none has been proved as efficient or reliable (Muthukumar, Rajkumar, Karthikeyan, et al, 2014;Muthukumar, Rajkumar, Rajesh, et al, 2014;Rajanarayanan & Archunan, 2011).…”