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Bioscientifica Proceedings (2020) 10 ISEDISED6 | DOI: 10.1530/biosciprocs.10.006

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Models of embryonic diapause in Carnivora

BD Murphy1 and JC Fenelon2

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1Centre de recherche en reproduction et fertilitè, Universitè de Montrèal, Quèbec, Canada; 2School of Biosciences, University of Melbourne, Melbourne, Australia


The phenomenon of obligate embryonic diapause, comprising developmental arrest at the blastocyst stage, has been recognized to occur in more than 60 species in three families in the Order Carnivora. The evolutionary advantage believed to be conferred by this trait is that it permits mating and parturition to occur at the most favorable times of year for reproductive success and offspring survival. The carnivore blastocyst in diapause consists of hundreds of cells, configured in the classic mammalian compartments of inner cell mass and trophoblast. It is encapsulated in a glycoprotein coat, derived, at least in part, from the zona pellucida of the parent oocyte. The temporal uncoupling of mating from parturition is regulated by changes in the annual photoperiod, mediated through the pineal gland, pars tuberalis a pars distalis of the pituitary and thyroid glands. In the best-studied species, the pituitary signal that awakes the embryo from arrest is prolactin, acting on the ovary and on the uterus. Ovarian signals, other than progesterone are not well understood, but it appears that there is an ovarian peptide essential for the reactivation of the embryo in mink. New studies have identified the uterine signals in the mink, and it has been shown that the synthesis and secretion of polyamines activates the mink embryo from diapause. While extensive progress has been made, it is not clear whether the regulatory mechanisms that have been identified in the better-known species are universal to carnivore diapause. As many of the carnivore species are endangered, further research on diapause is essential to their survival.

© Third International Symposium on Embryonic Diapause

Volume 10

3rd International Symposium on Embryonic Diapause

Society for Reproduction and Fertility 

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