Lee–Boot effect

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The Lee–Boot effect is a phenomenon concerning the suppression or prolongation of oestrous cycles of mature female mice (and other rodents), when females are housed in groups and isolated from males.{{cite journal|title=Spontaneous Pseudopregnancy in Mice|last1=Lee|first1=S. van der|last2=Boot|first2= L.M|journal=Acta Physiol. Pharmacol.|publisher=Neer.|volume=5|issue=213|date=1956|pages=213–215 |pmid=13402502 }}{{cite web|url=http://www.research.uci.edu/tmf/husbandry.htm|title=Mouse Husbandry, Breeding and Development: Pheromone Effects|publisher=Transgenic Mouse Facility, University of California}} It is caused by the effects of an estrogen-dependent pheromone, possibly 2,5-dimethylpyrazine, which is released via the urine and acts on the vomeronasal organ of recipients.{{cite book|last1=Carlson|first1=Neil R.|title=Physiology of behavior|url=https://archive.org/details/physiologybehavi00carl_811|url-access=limited|date=2013|publisher=Pearson|location=Boston|isbn=978-0205239399|page=[https://archive.org/details/physiologybehavi00carl_811/page/n355 335]|edition=11th}}{{cite journal |last1=Petrulis |first1=Aras |title=Chemosignals, Hormones and Mammalian Reproduction |journal=Hormones and Behavior |date=May 2013 |volume=65 |issue=5 |pages=723–41 |doi=10.1016/j.yhbeh.2013.03.011 |pmid=23545474|pmc=3667964 }} This pheromone lowers the concentration of luteinizing hormone and elevates prolactin levels, synchronising or stopping the recipient's cycle.{{Cite journal|last1=Jemiolo|first1=Bozena|last2=Novotny|first2=Milos|date=1994-03-01|title=Inhibition of sexual maturation in juvenile female and male mice by a chemosignal of female origin|journal=Physiology & Behavior|volume=55|issue=3|pages=519–522|doi=10.1016/0031-9384(94)90110-4|pmid=8190771|s2cid=28082749|issn=0031-9384}} This effect goes some way to explain why spontaneous pseudopregnancy 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 glands are required for production of the urine pheromone which is responsible for this effect.{{cite journal|author=Ma W, Miao Z, Novotny MV|title=Role of the adrenal gland and adrenal-mediated chemosignals in suppression of estrus in the house mouse: the Lee-Boot effect revisited.|journal=Biol Reprod|year=1998|volume=59|issue=6|pages=1317–20|pmid=9828173|doi=10.1095/biolreprod59.6.1317|doi-access=}}