Haemoglobin ontogeny in an inbred strain of the golden hamster was determined from 12 days in gestation to adulthood. Haemoglobins, separated by isoelectric focusing in polyacrylamide gel in a linear pH gradient (7.0 to 8.0), were quantified by optical density scanning (420 nm) of the unstained gels. Three species (adult haemoglobins) increase in proportion, one (15 % at 12 days gestation) becomes dominant (85 % in adults), and two (nearly absent at 12 days gestation) increase and exist as minor species in adults. Two species (foetal haemoglobins) decrease rapidly, one (37 % at 12 days gestation) to trace levels, the other (24 % at 12 days gestation) to a persistent 3 % in adults.
Isoelectric-focused haemoglobins were eluted individually and re-identified by isoelectric focusing, disk-gel electrophoresis, and vertical gel electrophoresis. Gel exclusion studies ruled out the possibility that any one haemoglobin species is a polymer of another.
Haemoglobin proportions determined by the technique used here, isoelectric focusing, are very reproducible, both from sample to sample and from hamster to hamster of any specific age. The presence of a foetal haemoglobin fraction persisting at significant levels into adulthood suggests that this small laboratory animal is a suitable model for studies on foetal haemoglobin synthesis.
An Evolutionarily Conserved Form of Gonadotropin-Releasing Hormone Coordinates Energy and Reproductive Behavior
