In vivo mechanisms of epithelial tissue morphogenesis

During animal development, a ball of cells (the blastula) forms from division of a single cell, the egg. This ball elongates to form the main body axis (gastrulation), which becomes divided into repeated regions (segmentation). The human vertebrate column is made from the embryonic regions generated by segmentation (somites). These processes are important and defects in body axis elongation can lead to neural tube problems, such as spina bifida.

We will investigate how embryos are shaped by studying tissue elongation and segmentation in fly embryos. These embryos can be watched live and easily manipulated both genetically and physically. We will study the role of the actomyosin cytoskeleton, which is an essential cellular structure, in tissue elongation and segmentation. This structure, which can be thought of as the cell’s ‘muscle’, is a contractile web made of proteins called actin and myosin, closely associated with the cell’s membrane. In tissue elongation and segmentation, the cells redistribute their actomyosin cytoskeleton, so that it is found more commonly along certain sides of the cell. This redistribution can cause cells to contract and push past each other, which causes tissue elongation.