A BALANCED LETHAL SEX-CHROMOSOME SYSTEM?
D000818:Animals; D002875:Chromosomes; D005260:Female; D010060:Ovulation; D011247:Pregnancy; D011270:Pregnancy, Animal; D012106:Research; D012377:Rodentia; D012730:Sex Chromosomes; D019849:Sex Determination Processes
CHROMOSOMES; EXPERIMENTAL LAB STUDY; OVULATION; PREGNANCY; PREGNANCY, ANIMAL; RODENTS; SEX DETERMINATION