Genetic control of hormone-induced ovulation rate in mice.
The nature of genetic differences in ovarian responsiveness to gonadotropins was examined in mouse strains and subspecies. Hormone-induced ovulation rate (HIOR) differed 5-fold between Mus musculus strains A/J (10.3 +/- 1.6 eggs in cumulus) and C57BL/6J (B6) (47.3 +/- 2.5 eggs in cumulus), and 6-fold among Mus spretus lines and crosses. Subspecies differed up to 10-fold in HIOR (Mus spretus/Ros: 4.8 +/- 1.0 eggs in cumulus versus B6). An additional experiment examined the genetics of HIOR in crosses. The number of eggs ovulated in response to equine chorionic gonadotropin (CG)/human CG averaged 8.4 +/- 0.9 in A/J, 40.7 +/- 1.7 in B6, 33.9 +/- 1.6 in B6AF1, and 20.2 +/- 0.3 in (B6xA)xA backcrosses. The 5-fold genetic differences in hormone-induced ovulation rate between Mus musculus strains A/J and B6 segregated in backcrosses as though they were controlled by the action of approximately 3 loci with major effects. This study demonstrates genetic variation in HIOR both within and between mouse subspecies, and provides confirmation that genetic differences are a major source of variation in the regulation of ovarian responsiveness to gonadotropins.
Spearow
J L
JL
Section of Neurobiology, Physiology and Behavior, University of California at Davis, Davis, California 95616, USA. jlspearow@ucdavis.edu
Barkley
M
M
D000818:Animals; D005260:Female; D006062:Gonadotropins / Q000502:physiology; D008297:Male; D051379:Mice / Q000235:genetics*; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D010053:Ovary / Q000502:physiology; D010060:Ovulation / Q000235:genetics* / Q000502:physiology
D006062:Gonadotropins