Now that hay fever season has started, sufferers are well aware
of the effect of histamines. However it is easy to forget that
histamine is also a neurotransmitter involved in controlling
memories, regulating sleep, and controlling secretion of gastric
acid. New research published in BioMed Central's open access
journal BMC Developmental Biology shows that for the purple sea
urchin (Strongylocentrotus purpuratus) histamine is also
responsible for controlling metamorphosis from a free swimming
larval form to the spiny adult living on the sea floor.
Echinoids (sea urchins and sand dollars) have evolved a range of
reproductive and developmental strategies. One of them involves
a free swimming (pelagic) larval form which after a period of
'competence', while the animal searches for an appropriate
settlement site, metamorphoses into the adult form (benthic)
which lives on the sea floor. In the purple sea urchin
metamorphic changes occur in response to specific environmental
cues that competent larvae become respon