Disruption of sexual behavior in male aromatase-deficient mice lacking exons 1 and 2 of the cyp19 gene

Biochem Biophys Res Commun. 1998 Nov 18;252(2):445-9. doi: 10.1006/bbrc.1998.9672.


Aromatase is known to be involved in the control of morphological, neuroendocrine, and behavioral sex differences in the brain. To study the detailed functions of aromatase in mouse brain, we generated aromatase-deficient mice that lack exons 1 and 2 and the proximal promoter region of the cyp19 gene by homologous recombination. The genotypes of offspring from heterozygous matings conformed to the Mendelian rule. The aromatase knockout (ArKO) male and female mice displayed no significant external morphological abnormalities, although the uteri of adult ArKO female mice were remarkably underdeveloped. Male-typical sexual behavior directed toward females was, however, strongly modified in the ArKO male mice. The ArKO male mice showed significantly prolonged latencies to mount and decreased numbers of mounts in response to receptive stimulus females. These results suggest an important participation of the aromatase gene in the reproductive behaviors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aromatase / deficiency*
  • Aromatase / genetics*
  • Aromatase / physiology
  • Base Sequence
  • DNA Primers / genetics
  • Exons
  • Female
  • Gene Targeting
  • Male
  • Mice
  • Mice, Knockout
  • Phenotype
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Deletion
  • Sexual Behavior, Animal / physiology*
  • Uterus / abnormalities


  • DNA Primers
  • Aromatase