The Lee–Boot effect is a phenomenon concerning the suppression or prolongation of
oestrous cycles
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...
of mature female mice (and other rodents), when females are housed in groups and isolated from males. It is caused by the effects of an estrogen-dependent
pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
, possibly
2,5-dimethylpyrazine,
which is released via the urine and acts on the
vomeronasal organ
The vomeronasal organ (VNO), or Jacobson's organ, is the paired auxiliary olfactory (smell) sense organ located in the soft tissue of the nasal septum, in the nasal cavity just above the roof of the mouth (the hard palate) in various tetrapods. ...
of recipients. This pheromone lowers the concentration of
luteinizing hormone
Luteinizing hormone (LH, also known as luteinising hormone, lutropin and sometimes lutrophin) is a hormone produced by gonadotropic cells in the anterior pituitary gland. The production of LH is regulated by gonadotropin-releasing hormone (GnRH) ...
and elevates
prolactin
Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pit ...
levels, synchronising or stopping the recipient's cycle.
This effect goes some way to explain why spontaneous
pseudopregnancy
In mammalian species, pseudopregnancy is a physical state whereby all the signs and symptoms of pregnancy are exhibited, with the exception of the presence of a fetus, creating a false pregnancy. The corpus luteum (the remains of an ovulated ovari ...
can occur in mice. The same response is invoked from isolated females when brought into contact with urine-soaked bedding from other females' cages. The
adrenal gland
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex which ...
s are required for production of the urine pheromone which is responsible for this effect.
See also
*
Menstrual synchrony
Menstrual synchrony, also called the McClintock effect, or the Wellesley effect, is a contested process whereby women who begin living together in close proximity would experience their menstrual cycle onsets (the onset of menstruation or menses) ...
*
Whitten effect The Whitten effect is stimulation, by male pheromones, of synchronous estrus in a female population.
Social signals, or social stimuli, have an effect on reproduction in all mammals. For certain female mice, the pheromones contained in the urine ...
References
Endocrinology
Ethology
Reproduction in mammals
{{Biology-stub