THE ORIGIN OF VERTEBRATE FOETAL MEMBRANES

The Origin of Vertebrate Gills

Pharyngeal gills are a fundamental feature of the vertebrate body plan [1]. However, the evolutionary history of vertebrate gills has been the subject of a long-standing controversy [2-8]. It is thought that gills evolved independently in cyclostomes (jawless vertebrates-lampreys and hagfish) and gnathostomes (jawed vertebrates-cartilaginous and bony fishes), based on their distinct embryonic o...

The origin of vertebrate limbs.

The earliest tetrapod limbs are polydactylous, morphologically varied and do not conform to an archetypal pattern. These discoveries, combined with the unravelling of limb developmental morphogenetic and regulatory mechanisms, have prompted a re-examination of vertebrate limb evolution. The rich fossil record of vertebrate fins/limbs, although restricted to skeletal tissues, exceeds the morphol...

Protein transmission across the rabbit foetal membranes.

Diagnosis of Premature Rupture of Foetal Membranes

Premature rupture of foetal membranes (PROM) complicates 10 % of pregnancies and is the most important identifiable cause of pre-term delivery. The diagnosis of PROM is based on the detection of amniotic fluid in the vagina. This can be achieved by chemical, clinical or biochemical methods. An ideal test should be specific for amniotic fluid and should not be affected by gestational age or inte...

Electrical potential differences across the foetal membranes of the rabbit.

T H E chemical composition of the foetal fluids in the rabbit was studied by Davies & Routh (1957). These investigators showed that the amniotic and exocoelomic fluids resembled extracellular fluid in their ionic composition whereas the allantoic fluid more closely resembled intracellular fluid. These findings were confirmed by Dickerson & McCance (1957). An experimental study of the trans-memb...