Main Cause of Whitten Effect in Mice
The main cause of the Whitten effect in mice is:
- Release of GnRH — Correct Answer
- Release of prostaglandins
- Release of prolactin
- Release of oxytocin
Correct Answer: Release of GnRH
The Whitten effect is triggered by the release of GnRH (Gonadotropin-Releasing Hormone) from the hypothalamus. When a male mouse is introduced into a group of female mice, male pheromones are detected via the VNO → signal reaches the hypothalamus → GnRH is released → synchronization of estrus in all female mice.
Whitten Effect — Detailed Mechanism
- Male mouse introduced into female group
- Male pheromones detected by Vomeronasal organ (VNO) of females
- VNO → limbic system → hypothalamus → GnRH released
- GnRH → anterior pituitary → FSH & LH release
- FSH/LH → follicular development & ovulation → synchronization of estrus in all females
Practical Application
The Whitten effect is used in livestock management — the Ram effect (similar to Whitten effect in sheep) is used to synchronize estrus in ewes by introducing a ram after a period of separation. This allows for controlled and synchronized mating.
Contrast with Bruce Effect
- Whitten effect: GnRH release → estrus synchronization
- Bruce effect: Blockage of prolactin release → pregnancy termination
📚 About this Topic — Animal Physiology
This multiple choice question is from Animal Physiology, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Physiology to strengthen your preparation.
