Development of a modified artificial insemination technique combining penile vibration stimulation and the swim-up method in the common marmoset.

The common marmoset, Callithrix jacchus, is used as a New World monkey species in biomedical studies because of its small body size and good reproduction in captivity. A modified artificial insemination technique was developed in this species to encourage breeding of lines carrying interesting genes and traits. Fresh semen was collected by penile vibratory stimulation. Medium containing highly motile sperm was inseminated into the uterus using a catheter. Seven females were inseminated using freshly prepared sperm from different males every day for 3 days including the expected ovulation day. As a result, four females conceived, and three females delivered six offspring in total (two singletons and one quadruplet). The paternity of the newborns was determined using microsatellite markers to accurately pinpoint the timing of insemination and ovulation. It is expected that our artificial insemination protocol can be effectively used to establish marmoset lines and genetically manage marmoset colonies.