Uterine Proteins in the Marsupial, Didelphis Marsupialis Virginiana, During Gestation

Abstract

The No r t h American opossum, Didelphis marsupialis virginiana, is a polyovular, polyoestrous marsupial. The gestation period of 13 days is the same length as the luteal phase of the cycle (Hartman, 1923(Hartman, , 1925 (Hartman, 1923;Renfree, 1974). After ovulation, the two uteri increase greatly in size and turgidity, due to an accumulation of fluid in the hypertrophied mucosa and the development of a rich supply of capillaries and venules (Harman, 1923 (Renfree, 1974) were included for comparison.Opossums were collected and housed as already described (Renfree, 1974

Uterine histology and reproductive cycles in pregnant and non-pregnant opossums, Didelphis virginiana

“…The uterine gland index declined after mid-gestation, consistent with the pattern of endometrial weights (Renfree, 1975) embryotrophe (Sharman, 1961), Padykula & Taylor (1971 described the ultrastructure of the surface epithelium as indicative of a transport function. Therefore, the contribution of glandular epithelium to embryo nutrition might diminish during late gestation and be supplanted by the surface epithelium.…”

Uterine and embryonic metabolism after diapause in the tammar wallaby, Macropus eugenii

“…Three females had no blastocyst (one each at Days 0, 7 and 9), and one of the Day-0 blastocysts was lost when it adhered inside a pipette during transfer. The two remaining Day-0 blastocysts appeared normal, and both had low rates of uptake and incorporation of uridine ( (Hill & O'Donoghue, 1913;Renfree & Tyndale-Biscoe, 1973;Shorey & Hughes, 1973;Renfree, 1973Renfree, , 1975Shaw & Rose, 1979;Fleming & Harder, 1981a, b), the results from these two non-pregnant females were included with those from pregnant females for statistical analysis. Leucine incorporation changed markedly after removal of pouch young.…”

Scanning Electron Microscopic Observations on the 9-Day Opossum (<i>Didelphis virginian</i><i>a</i>) Embryo

“…During this period of gestation, the opossum embryos lie free within the uterine lumen and are thought to be nurtured by secretions from the uterus. Uterine secre tions of Didelphis are rich in proteins, principally albu mins and prealbumins [Renfree, 1975]. These secretions are thought to be a major source of nutrition during the free vesicle phase.…”

“…The nutrients make their way to the growing embryo through the enveloping shell mem brane and then are thought to be absorbed by the extraembryonic ectoderm. The fluid within the lumen of the embryonic sphere contains prealbumin proteins that differ in composition from those found in uterine secre tions [Renfree, 1975]. Because the extraembryonic ectoderm apparently is active in the absorpiton of mate rials, morphological differences in endodcrmal cells that lie immediately adjacent to this active form might have been predicted.…”