Effect of Unilateral Ovariectomy on Twinning Frequency in the Marmoset

Abstract

The marmosets, small New World primates of the family Callithricidae, were reported by Wislocki (1939) (Gengozian, 1970), and the sexes of the twins approximate to those expected for fraternal twinning, i.e.

Single-Born Marmosets without Hemopoietic Chimerism: Naturally Occurring and Induced

“…Prompted by the early reports of Hill and Hill [11] and Wislocki [18], describing the presence of corpora lutea from each ovary, we attempted to achieve true single-born marmosets by simple unilateral ovariectomies. As reported in that study, the frequency of twinning derived from five such single-ovary breeders did not differ from that obtained from our nonoperated females [7], This observation was not too surprising in view of the fact that in many polytocous nonprimate species the partial or complete removal of one ovary leads to an increase in the number of follicles formed by remaining ovarian tissue. This phenomenon, referred to as the 'law of follicular constancy' [13], is thought to be controlled by a hormonal feedback balance between the pituitary and ovaries [16].…”

Reproductive factors affecting survivorship in captive callitrichidae

“…Cases of singlet births would then occur when one embryo does not survive and is resorbed or expelled at parturition. There have not been many longitudinal studies of prenatal survivorship, but many studies have found evidence (blood chimerism, presence of two placentae and/or two corpora lutea) of loss of a co-twin in utero (Wislocki, 1939;Gengozian and Merritt, 1970;Chambers and Hearn, 1985;Tardif, personal communication). If ovulation and fertilization of two ova were standard, the singleton may not receive the advantage of increased birth weight and prenatal nutrition.…”

“…High rates of in-utero loss are found in most prolific species (Bindon, 1984;Hanrahan, 1980). Gengozian and Merritt (1970) found that in a sample of births from unilateral ovariectomized female marmosets, all single births had either two placentae or were chimeric by analysis of sex chromosomes, suggesting loss of a sibling in utero.…”

Number of ovulations in the marmoset monkey (Callithrix jacchus): Relation to body weight, age and repeatability

“…While these results suggest a link between reproductive output and energy availability, factors such as maternal age and possibly shifting composition of the breeding population represent potential confounding variables in these studies. In addition, these studies cannot distinguish between effects on number of ovulations versus prenatal survivorship, given that death and reabsorption of some fetuses in a litter, resulting in litter size reduction in utero, has been demonstrated to occur in callitrichids [Gengozian & Merritt, 1970;Jaquish et al, 1996].…”