Cell Communication Mechanisms Research Articles

Correlation of asymmetric Notch2 expression and mouse incisor rotation

Notch signaling defines an evolutionarily conserved cell communication mechanism, which enables neighboring cells to adopt different fates. Furthermore, Notch signaling may create boundaries that direct both the growth and patterning of the developing organs. Here we report on the expression of Notch receptors during the development of rodent incisors. Before the aquisition of their characteristic shape, incisors rotate antero–posteriorly and become asymmetric at their labial–lingual axis. Notch2 is expressed only in the anterior part of the developing incisors, well before their rotation, while Notch2 expression was symmetrical in the developing molars. This is the first demonstration of an asymmetric gene expression pattern during the rotation of the rodent incisors.

Directed inflammation: The phylogeny of lymphokines

Implants of slow-release polymer Elvax-40 containing purified sea star factor (SSF) and rabbit T cell lymphokines were sutured to the coelomic wall of the distal arms of the sea star Asterias forbesi . Scanning electron microscopic evaluation of the pellet surface demonstrated adherence and spreading of coelomocytes over SSF- or lymphokine-containing pellets examined from 6 to 48 hours after implantation. These observations indicate that purified SSF and rabbit lymphokines demonstrate cross-phylum biological mimicry, implying a phylogenetic link between vertebrate and invertebrate cell communication mechanisms in immunoprotective functions.

Communication Between Normal Human Epidermal Cells in Vitro

Normal human epidermal cells in vitro were found to be electrically coupled indicating the presence of low resistance pathways between cells. Ultrastructurally, cells were connected by tight and gap junctions. The mechanism and possible significance of cell communication are discussed.