Electrophoretic characterization of equine oviductal fluid.
Abstract: To characterize further the events involved in fertilization and early embryonic development in the mare, effect of the estrous cycle on oviductal fluid proteins was investigated. Five mares had indwelling cannulas placed in their oviducts so that fluid could be collected throughout the estrous cycle. Daily fluid volumes were recorded and mares were monitored for signs of standing estrus. Oviductal fluid samples were pooled across mares according to stage of cycle (either estrus or nonestrus) for further analysis. Two-dimensional polyacrylamide gel electrophoresis (PAGE) was used to determine proteins present in estrus-associated and nonestrus-associated equine oviductal fluid as compared to blood serum from the same mares. Oviductal fluid volumes increased significantly during estrus to an average of 3.94 ml/24 hr from 1.44 ml/24 hr during nonestrus. Total oviductal protein increased significantly from 24.6 mg/24 hr during nonestrus to 53.9 mg/24 hr during estrus. One-dimensional PAGE demonstrated that the proteins in equine oviductal fluid were present throughout the cycle and also common to equine serum. Reducing conditions revealed one band at 106 kDa detected only in nonestrus-associated oviductal fluid, while nonreducing conditions revealed bands at 48 and 25 kDa that were present in oviductal fluid in general. Two-dimensional PAGE demonstrated three 50 kDa proteins that were detected only in estrus-associated oviductal fluid and several 24 kDa proteins detected only in nonestrus-associated oviductal fluid. Those proteins found only in estrus-associated oviductal fluid may be vital to the fertilization process, while those found only in nonestrus-associated oviductal fluid may be vital to early embryonic development.
Publication Date: 1994-05-01 PubMed ID: 8176362DOI: 10.1002/jez.1402680608Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research investigates how the estrous cycle affects proteins in the oviductal fluid of mares, potentially influencing fertilization and early embryonic development. It found a significant increase in fluid volumes and protein quantity during estrus, along with the presence of certain proteins exclusive to specific stages of the cycle.
Research Approach and Methodology
- As part of the study, cannulas (small tubes) were inserted in the oviducts of five mares to collect oviductal fluid throughout their estrous cycles. The horses’ behaviors were monitored for signs of standing estrus, a condition indicating ovulation and fertility.
- Daily fluid volumes were recorded, and oviductal fluid samples were combined according to the stage of the cycle; estrus (when the mare is in heat and fertile) or non-estrus (when she is not).
- These samples were studied using two-dimensional polyacrylamide gel electrophoresis (PAGE), which enables the separation and identification of proteins. The proteins found in estrus-associated and non-estrus-associated equine oviductal fluid were compared to proteins found in the blood serum from the same mares.
Key Findings
- Detailed analysis revealed that oviductal fluid volumes significantly increased during estrus, averaging 3.94 milliliters in 24 hours as compared to 1.44 milliliters during non-estrus.
- The total quantity of protein in the oviductal fluid also significantly increased — from 24.6 milligrams in 24 hours during non-estrus to 53.9 milligrams during estrus.
- Further one-dimensional PAGE analysis showed that proteins in the equine oviductal fluid are present throughout the cycle and are also common to equine serum.
- Under reducing conditions, one protein band, weighing 106 kDa, was detected only in the non-estrus-associated oviductal fluid.
- Under non-reducing conditions, protein bands were detected at 48 and 25 kDa in the general oviductal fluid.
- However, using two-dimensional PAGE, they discovered three 50 kDa proteins exclusively present in estrus-associated oviductal fluid and several 24 kDa proteins specific to non-estrus-associated oviductal fluid.
Implications of the Findings
- The researchers propose that the proteins exclusively found in the estrus-associated oviductal fluid could play an essential part in the fertilization process.
- Conversely, those proteins detected only in non-estrus-associated oviductal fluid might be crucial for early embryonic development.
Cite This Article
APA
Willis P, Sekhar KN, Brooks P, Fayrer-Hosken RA.
(1994).
Electrophoretic characterization of equine oviductal fluid.
J Exp Zool, 268(6), 477-485.
https://doi.org/10.1002/jez.1402680608 Publication
Researcher Affiliations
- Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602.
MeSH Terms
- Animals
- Blood Proteins / analysis
- Body Fluids / chemistry
- Electrophoresis, Gel, Two-Dimensional
- Electrophoresis, Polyacrylamide Gel
- Estrus
- Fallopian Tubes / chemistry
- Female
- Horses
- Proteins / analysis
Citations
This article has been cited 1 times.- Natalia B, John P, Wiesława M, Wojciech N, Marzenna PO, Katarzyna HL, Michał K, Małgorzata O. Age-related changes in the cytoplasmic ultrastructure of feline oocytes. Sci Rep 2025 Apr 12;15(1):12668.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
