Artificial inseminationwas performed on Days 9,10, and
11 after cloprostenol treatment. The females were sedated
with ketamine hydrochloride (Ketalar; Daiichi Sankyo
Propharma, Tokyo, Japan) at a dose of 5 mg/kg body weight.
A 4-Fr multipurpose catheter (1.35-mm outer diameter;
Atom Medical, Tokyo, Japan) attached to a 1-ml syringewas
filled with 200 mL sperm suspension and was inserted
approximately 4 cm through the vagina and most likely
into the uterine cavity after lubrication with an obstetrical
gel. This distance is the approximate length of the entire
vagina (about 3.4 cm) and uterus (about 0.8 cm) in the
marmoset [19]. Sperm were deposited by gently depressing
the syringe plunger. After AI, the catheter was removed
slowly, and the female was placed on a heating plate to
recover from sedation.