Early Embryonic Development in Agriculturally Important Species
Fuller W Bazer1, Gregory A Johnson2
1Department of Animal Science, Texas A&M University, College Station, TX 77843-2471, USA.
Animals : an Open Access Journal From MDPI
|July 13, 2024
Summary
Early pregnancy in pigs, sheep, cows, and horses involves complex embryonic development and implantation. Successful pregnancy recognition signals are crucial for maintaining corpora lutea and progesterone secretion.
Area of Science:
- Comparative embryology
- Reproductive biology
- Mammalian pregnancy
Background:
- Fertilization is not a limiting factor for pregnancy establishment in pigs, sheep, cows, and horses.
- Embryonic development to the blastocyst stage is a common early step across these species.
Purpose of the Study:
- To review early embryonic development, implantation, and pregnancy recognition signaling in domestic ungulates.
- To compare and contrast these processes in pigs, sheep, cows, and horses.
Main Methods:
- Literature review of early embryonic development and implantation.
- Comparative analysis of pregnancy recognition mechanisms.
Main Results:
- Pigs, sheep, and cows exhibit central-type implantation with blastocyst elongation and uterine apposition.
- Equine blastocysts migrate within the uterus before attaching to the uterine luminal epithelium (LE).
- Pregnancy recognition signals vary, with pigs using interleukin 1 beta and interferon gamma, while sheep and cows use interferon tau to maintain corpora lutea.
Conclusions:
- Implantation involves interactions between extracellular matrix (ECM) proteins and integrins.
- Understanding these diverse reproductive strategies is key to improving livestock fertility and managing pregnancy.
