Tackling nervous movements: Migration of Q neuroblasts and their descendents in Caenorhabditis elegans
Year: 2009
Type: dissertation
Abstract: Cell migration is a crucial process in animal development and defective cell migration can\nlead to developmental abnormalities and disease. C.elegans has been widely used as a model\norganism to study the control of cellular movements in vivo. Particularly, the migration of\ntwo neuronal stem cells, the left and right Q neuroblasts, and their descendents has been\nproven to be an excellent model system to study the developmental control of cell migration.\nAt hatching, the left (QL) and right (QR) Q neuroblasts are located in the lateral row of\nhypodermal seam cells. In the first larval stage both Q neuroblasts delineate from the row of\nseam cells, migrate a short distance and then undergo cell division. Q daughter cells\ncontinue to migrate along the anteroposterior axis of the animal. At hatching both Q\nneuroblasts are similar in shape and morphology. Interestingly, the QR neuroblast and its\ndescendents migrate anteriorly while QL and its descendents migrate posteriorly. Extensive\ngenetic analysis revealed many insights into the genetic control of this asymmetric process.\nA highly conserved canonical Wnt/ß-catenin pathway regulates the posterior migration of\nQL descendent cells while a non-canonical Wnt signaling pathway controls anterior\nmigration of QR daughter cells. Furthermore, it was shown that Homeobox genes were also\ninvolved in the control of Q cell migration. For example, the Antennapedia-like gene mab-5\nis both necessary and sufficient for posterior migration of QL daughter cells. It is widely\naccepted that cell migration requires dramatic reorganizations of the actin cytoskeleton.\nIndeed, many genes that were shown to be involved in regulating actin reorganizations were\nalso implicated in the control of Q cell migration. Finally, in determining the direction of\nmigration, the initial short-range migration of Q neuroblasts was shown to be critical since\nmutations affecting this process were also shown to result in aberrant migration of Q\nneuroblast descendents. Here, I will give an overview of the various control mechanisms\nknown to date that are involved in the regulation of Q cell migration.
Author: Teije C. Middelkoop
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2156647047