Production of Prostaglandin F2α and Its Metabolite by Endometrium and Yolk Sac Placenta in Late Gestation in the Tammar Wallaby, Macropus eugenii1

Shaw, Geoff; Gehring, Helen M.; Bell, ET

doi:10.1095/biolreprod60.3.611

Cited by 20 publications

(12 citation statements)

References 28 publications

(45 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Prostaglandins have been shown to be important to normal birth mechanisms in other marsupials such as the tammar wallaby [50, 51]. Injection of exogenous prostaglandin F2 (PGF2) have also been shown to induce birthing in marsupials [50, 52].…”

Section: Discussionmentioning

confidence: 99%

Transcriptomic Changes Associated with Pregnancy in a Marsupial, the Gray Short-Tailed Opossum Monodelphis domestica

2016

View full text Add to dashboard Cite

Live birth has emerged as a reproductive strategy many times across vertebrate evolution; however, mammals account for the majority of viviparous vertebrates. Marsupials are a mammalian lineage that last shared a common ancestor with eutherians (placental mammals) over 148 million years ago. Marsupials are noted for giving birth to highly altricial young after a short gestation, and represent humans’ most distant viviparous mammalian relatives. Here we ask what insight can be gained into the evolution of viviparity in mammals specifically and vertebrates in general by analyzing the global uterine transcriptome in a marsupial. Transcriptome analyses were performed using NextGen sequencing of uterine RNA samples from the gray short-tailed opossum, Monodelphis domestica. Samples were collected from late stage pregnant, virgin, and non-pregnant experienced breeders. Three different algorithms were used to determine differential expression, and results were confirmed by quantitative PCR. Over 900 opossum gene transcripts were found to be significantly more abundant in the pregnant uterus than non-pregnant, and over 1400 less so. Most with increased abundance were genes related to metabolism, immune systems processes, and transport. This is the first study to characterize the transcriptomic differences between pregnant, non-pregnant breeders, and virgin marsupial uteruses and helps to establish a set of pregnancy-associated genes in the opossum. These observations allowed for comparative analyses of the differentially transcribed genes with other mammalian and non-mammalian viviparous species, revealing similarities in pregnancy related gene expression over 300 million years of amniote evolution.

show abstract

Section: Discussionmentioning

confidence: 99%

Transcriptomic Changes Associated with Pregnancy in a Marsupial, the Gray Short-Tailed Opossum Monodelphis domestica

2016

View full text Add to dashboard Cite

show abstract

“…Prostaglandins are an important mediator of parturition in the tammar wallaby . Production of prostaglandin F2a in vitro increases in endometrial and placental explants on the last 2 days of gestation (Shaw et al 1999). This alone may be sufficient to stimulate uterine contractions and initiate parturition (Shaw, 1983).…”

Section: Release Of Mesotocinmentioning

confidence: 99%

The role of oxytocin and regulation of uterine oxytocin receptors in pregnant marsupials

Parry

Bathgate

2000

Experimental Physiology

View full text Add to dashboard Cite

The oxytocin-like peptide of most Australian marsupials is mesotocin, which differs from oxytocin by a single amino acid. This substitution has no functional significance as both peptides have equivalent affinity for and biological activity on the marsupial oxytocin-like receptor. A role for mesotocin in marsupial parturition has been demonstrated in the tammar wallaby where plasma mesotocin concentrations increase less than one minute before birth. Infusion of an oxytocin receptor antagonist at the end of gestation disrupts normal parturition, probably by preventing mesotocin from stimulating uterine contractions. In the absence of mesotocin receptor activation, a peripartum surge in prostaglandins is delayed which suggests a functional relationship between mesotocin, prostaglandin release and luteolysis. Female marsupials have anatomically separate uteri and in monovular species, such as the tammar wallaby, only one uterus is gravid with a single fetus whereas the contralateral uterus remains non-gravid. We have used this unique animal model to differentiate systemic and fetal-specific factors in the regulation of uterine function during pregnancy. The gravid uterus in the tammar wallaby becomes increasingly sensitive to mesotocin as gestation proceeds, with the maximum contractile response observed at term. This is reflected in a large increase in mesotocin receptor concentrations in the gravid uterus, and a downregulation in the non-gravid uterus in late pregnancy. The upregulation in myometrial mesotocin receptors is pregnancy-specific and independent of systemic steroids. One factor that may influence mesotocin receptor upregulation in the gravid uterus in late pregnancy is mechanical stretch of the uterus caused by the growing fetus. Our data highlight that a local fetal influence is more important than systemic factors in the regulation of mesotocin receptors in the tammar wallaby. Experimental Physiology (2000) 85S, 91s-99sMammals evolved from reptile-like ancestors sometime between the late Triassic and Cretaceous periods, 190-100 million years ago, into prototherians (or monotremes), metatherians (or marsupials) and eutherians. One of the main characteristics of mammals is their ability to provide offspring with milk in the immediate postnatal period. Essential for lactation is the production of the nonapeptide hormone oxytocin by the magnocellular neurones of the hypothalamus. Release of oxytocin from the posterior pituitary, induced by the sucking stimulus of the young, causes contractions of the myo-epithelial cells of the mammary gland which results in milk ejection. The other main physiological effect of oxytocin in eutherians is to stimulate smooth muscle contractions of the uterus during birth.

show abstract

“…Production of PGE 2 by the placenta at the end of pregnancy in the sheep provides an important trophic drive to the fetal HPA axis [27], and the resulting increase in cortisol stimulates further PGE 2 release, creating a positive feedback loop. Prostaglandin synthesis by the tammar placenta and endometrium increases over the last 2 days of pregnancy [15,16], paralleling fetal cortisol concentrations. Cortisol synthesis by the fetal adrenal of the tammar is stimulated by PGE 2 in vitro, suggesting an adrenocorticotrophic role for increased placental PGE 2 production during parturition in this marsupial [15,16].…”

Section: Discussionmentioning

confidence: 99%

“…Prostaglandin synthesis by the tammar placenta and endometrium increases over the last 2 days of pregnancy [15,16], paralleling fetal cortisol concentrations. Cortisol synthesis by the fetal adrenal of the tammar is stimulated by PGE 2 in vitro, suggesting an adrenocorticotrophic role for increased placental PGE 2 production during parturition in this marsupial [15,16]. Cortisol synthesis by the fetal adrenal in vitro is also stimulated by ACTH, which suggests that the corticotrophs in the pituitary [11] may stimulate cortisol as in eutherians [28,29].…”

Section: Discussionmentioning

confidence: 99%

“…Glucocorticoids are also involved in maturation of the lungs of the tammar wallaby fetus [14]. The choriovitelline (yolk sac) placenta of the tammar wallaby produces increasing amounts of PGE 2 and PGF 2␣ at the end of gestation [15,16], and it is likely that this enters the fetal and maternal circulation. The choriovitelline (yolk sac) placenta of the tammar wallaby produces increasing amounts of PGE 2 and PGF 2␣ at the end of gestation [15,16], and it is likely that this enters the fetal and maternal circulation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cortisol in Fetal Fluids and the Fetal Adrenal at Parturition in the Tammar Wallaby (Macropus eugenii )1

Ingram

Shaw

Renfree

1999

Biology of Reproduction

Self Cite

View full text Add to dashboard Cite

Glucocorticoid hormones may play a critical role in initiating parturition in tammar wallabies. In this study, we investigated the concentration of cortisol in fetal fluids and cortisol production by fetal adrenals over the last 3 days of the 26-day pregnancy and within 24 h postpartum. The fetal adrenals almost doubled in size between Days 24 and 26 of pregnancy, and their cortisol content increased over 10-fold during this period, from 10 pg to over 100 pg per adrenal pair. After birth, neonatal adrenals continued to grow, but cortisol content fell dramatically to 20 pg. The prepartum increase in adrenal cortisol was reflected by a substantial rise in cortisol concentrations in yolk sac fluid, allantoic fluid, and fetal blood, which were below 10 ng/ml on Day 24 and rose to over 40 ng/ml by Day 26. Cortisol concentrations in neonatal blood decreased postpartum, mirroring decreased cortisol content in neonatal adrenals. Cortisol production by the fetal adrenal was stimulated in vitro by ACTH and prostaglandin E2, suggesting that the in vivo increase may be stimulated by release of ACTH from the fetal hypothalamic-pituitary axis and prostaglandin E2 from the placenta. These results indicate that increasing cortisol production by the fetal adrenal is a characteristic of late pregnancy in the tammar wallaby and support the suggestion that fetal cortisol may trigger the initiation of parturition in this marsupial species.

show abstract

Production of Prostaglandin F2α and Its Metabolite by Endometrium and Yolk Sac Placenta in Late Gestation in the Tammar Wallaby, Macropus eugenii1

Cited by 20 publications

References 28 publications

Transcriptomic Changes Associated with Pregnancy in a Marsupial, the Gray Short-Tailed Opossum Monodelphis domestica

Transcriptomic Changes Associated with Pregnancy in a Marsupial, the Gray Short-Tailed Opossum Monodelphis domestica

The role of oxytocin and regulation of uterine oxytocin receptors in pregnant marsupials

Cortisol in Fetal Fluids and the Fetal Adrenal at Parturition in the Tammar Wallaby (Macropus eugenii )1

Contact Info

Product

Resources

About