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Australian Journal of Zoology Australian Journal of Zoology Society
Evolutionary, molecular and comparative zoology
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RESEARCH ARTICLE
Contents Vol 54(3)

Early pregnancy factor in marsupials

Y. P. Cruz A D , H. Morton B , A. C. Cavanagh B , L. Selwood C , S. D. Wilson A and M. Sasaki A
+ Author Affiliations
- Author Affiliations

A Department of Biology, Oberlin College, Oberlin, OH 44074, USA.

B School of Medicine, University of Queensland, Brisbane, Qld 4029, Australia.

C Department of Zoology, University of Melbourne, Parkville, Vic. 3010, Australia.

D Corresponding author. Email: yolanda.p.cruz@oberlin.edu

Australian Journal of Zoology 54(3) 211-215 https://doi.org/10.1071/ZO05050
Submitted: 31 August 2005  Accepted: 8 March 2006   Published: 22 June 2006

Abstract

Maternal recognition of pregnancy in marsupials occurs in more subtle ways than it does in eutherians. For instance, unlike in eutherians, the plasma progesterone profiles of pregnant and non-pregnant animals are similar during the luteal phase. It is typically during the brief luteal phase that both gestation and parturition occur in marsupials. Yet histological and physiological changes have been documented between gravid and non-gravid uteri in certain monovular marsupials and between pregnant and non-pregnant animals in polyovular marsupials. Early pregnancy factor (EPF), a 10.8-kDa serum protein known to be homologous to chaperonin 10, is associated with maternal immunosuppression, embryonic development and pregnancy in eutherian mammals. It has been reported in two Australian marsupials: the dasyurid Sminthopsis macroura and the phalangerid Trichosurus vulpecula. This paper documents its occurrence in the New World didelphid Monodelphis domestica. EPF is detectable by rosette inhibition assay in the peripheral circulation of pregnant but not of non-pregnant or pseudopregnant animals. Our work focuses on the embryo–maternal signalling role of EPF during pregnancy. Because progesterone-driven changes are similar in pregnant and non-pregnant marsupials, these animals are an excellent laboratory model in which to investigate the role of EPF in orchestrating the physiological changes necessary to sustain pregnancy.


Acknowledgment

YPC was funded by research grants from Oberlin College. She acknowledges with gratitude the technical assistance of Jasmine McCammon and Twila Conley. The use of M. domestica in this study was approved by the Institutional Animal Care and Use Committee of Oberlin College.


References

Athanasas, S. , Quinn, K. A. , Wong, T.-Y. , Rolfe, B. E. , Cavanagh, A. C. , and Morton, H. (1989). Passive immunization of pregnant mice against early pregnancy factor (EPF) causes loss of embryonic viability. Journal of Reproduction and Fertility 87, 495–502.
| PubMed | Cui S., Griffith N., Nanayakkara K., Cruz Y., and Selwood L. (2002). Developmental targets for fertility control in the brushtail possum. In ‘Report of Conference held under the Auspices of the National Strategy Committee for Possum and Bovine Tb Control, 2–4 April 2001’. pp. 6–11. (New Zealand Ministry of Agriculture and Forestry: Wellington.)

Curlewis, J. , and Stone, G. M. (1986). Effects of oestradiol, the oestrous cycle and pregnancy on weight, metabolism and cytosol receptors in the uterus of the brush-tail possum (Trichosurus vulpecula). Journal of Endocrinology 108, 201–210.
| PubMed | Tyndale-Biscoe C. H. (1997). Marsupials and modern biology – breaking the paradigms. In ‘Marsupial Biology: Recent Research, New Perspectives’. (Eds N. Saunders and L. Hinds.) pp. 1–19. (University of New South Wales Press: Sydney.)

Tyndale-Biscoe C. H., and Renfree M. B. (1987). ‘Reproductive Physiology of Marsupials.’ (Cambridge University Press: Cambridge.)

Von der Borsch, S. M. (1963). Unilateral hormone effect in the marsupial Trichosurus vulpecula. Journal of Reproduction and Fertility 5, 447–449.
| PubMed |

Walker, M. T. , and Rose, R. (1981). Prenatal development after diapause in the marsupial Macropus rufogriseus. Australian Journal of Zoology 29, 167–187.
| Crossref | GoogleScholarGoogle Scholar |

Wallace, G. I. (1981). Uterine factors and delayed implantation in macropodid marsupials. Journal of Reproduction and Fertility. Supplement 29, 173–181.
| PubMed |

Zhang, B. , Harness, J. , Somodevilla-Torres, M. J. , Hillyard, N. C. , and Mould, A. W. , et al. (2000). Early pregnancy factor suppresses experimental autoimmune encephalomyelitis induced in Lewis rats with myelin basic protein and in SJL/J mice with myelin proteolipid protein peptide 139–151. Journal of the Neurological Sciences 182, 5–15.
| Crossref | GoogleScholarGoogle Scholar | PubMed |

Zhang, B. , Walsh, M. D. , Nguyen, K. B. , Hillyard, N. C. , Cavanagh, A. C. , McCombe, P. A. , and Morton, H. (2003). Early pregnancy factor treatment suppresses the inflammatory response and adhesion molecule expression in the spinal cord of SJL/J mice with experimental autoimmune encephalomyelitis and the delayed-type hypersensitivity reaction to trinitrochlorobenzene in normal BALB/c mice. Journal of the Neurological Sciences 212, 37–46.
| Crossref | GoogleScholarGoogle Scholar | PubMed |