Visualization of N-cadherin protein expression during the emigration of chicken trunk neural crest cells

Abstract

Emigration of trunk neural crest cells from the developing neural tube requires the breakage or rearrangement of cadherin-containing adherens junctions between the cells. I therefore examined the distribution of N-cadherin protein in chicken trunk neural crest cells as they emerged from the neural tube. To identify emerging neural crest cells, embryos were electroporated at the 12 to 16 somite stage of development with cDNA constructs encoding green or red fluorescent proteins and were allowed to develop for a further 12 to 24 hours before fixation. Sections or whole mounts then were stained with anti-cadherin antibodies and examined by conventional or confocal microscopy. As expected from previous work, fully-emigrated cells did not express detectable levels of surface N-cadherin. In some cases, cells that had not fully emerged from the neural tube appeared to retain surface-localized N-cadherin at areas of apposition to other neural tube cells. This suggests that modulation or breakage of N-cadherin-containing adherens junctions may be involved in control of neural crest emigration in the trunk. This work was supported by a Grant-in-Aid from the American Heart Association Western Regional Affiliates.