Producing timed-pregnant Mongolian gerbils for developmental studies

Abstract

The developing fetus is differentially susceptible to chemicals and pathogens depending on the stage of its development. In developmental studies, embryos or fetuses therefore must be exposed to experimental interventions at the same gestational stage. Acquiring sufficient numbers of embryos of the same developmental stage requires the use of timed-pregnant animals. Timed-pregnant Mongolian gerbils currently are not available for purchase. The authors developed a novel method for timed mating of virgin female gerbils. Female gerbils were housed in the same cage as males, but physically separated by a partition, for 3 d in order to expose the females to the males' pheromones before they were allowed to interact. Females were monitored for lordosis to determine sexual receptivity. Lordosis was observed in 10 of 15 females (67%), and 9 of these females (90%) became pregnant. When lordosis was not observed, none of the females became pregnant. These results demonstrate that the timed mating method produces a high rate of mating success and indicate that lordosis is a reliable predictor of sexual receptivity and subsequent successful mating in the Mongolian gerbil.

Beyond sex and aggression: testosterone rapidly matches behavioural responses to social context and tries to predict the future

“…All females were in late stages of pregnancy; this is consistent with the typical latency to copulation after initial pairing (i.e. typically within 2 days) and a gestation period of 21 days [36].…”

Dose Response of Listeria monocytogenes Invasion, Fetal Morbidity, and Fetal Mortality after Oral Challenge in Pregnant and Nonpregnant Mongolian Gerbils

“…The animals were bred in-house according to a method developed for breeding timed-pregnant gerbils described by Roulo et al (24). Briefly, male gerbils aged Ͼ90 days and virgin female gerbils aged 80 to 95 days and averaging 71.0 g (Ϯ8.4 g) were acclimated in separate rooms for a minimum of 7 days before the female was placed into a divided cage with a male for a 3-day period meant to induce estrus.…”

A review of fundamental principles for animal models of DOHaD research: an Australian perspective

“…73,74 Co-housing strategies may be used in rodents to expose females to male pheromones without direct contact. [75][76][77] Clear plastic partitions are used to physically separate males from females but still allow pheromones to reach the female. Observing lordosis (a specific curved posture indicating willingness to mate) in the female indicates sexual receptivity.…”

“…Co-housing strategies may be used in rodents to expose females to male pheromones without direct contact 75 77 Clear plastic partitions are used to physically separate males from females but still allow pheromones to reach the female.…”