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Showing posts with the label Development

How has the study of the origins and development of the neural crest shed light on our understanding of development mechanisms and the origins of development disease?

Define neural crest as the ectodermal cells from the lateral neural plate. They go on to form various parts of the body such as: Skull + teeth, PNS, calcitonin producing cells, parathyroid glands, carotid bodies, spiral septum, adrenal chromaffin cells. They start from the neural tube but during development they migrate . Subsequently the study of these have given greater insight into cell migration mechanisms. Furthermore these neural crest cells are plastic and have allowed for improved understanding into how regulative development occurs. Finally labelling experiments have allowed us to trace the lineage of differentiated cells to form fate maps . This has enabled us to understand the origins of many types of cells are actually neural crest and subsequenty help us to understand why conditions such as DiGeorge’s which causes craniofacial deformities can also cause      thyroid gland agenesis and persistent truncus arteriosus. Neural crest fate mappi...

Discuss the role of hox genes in animal development.

Segmentation is a key process in animal development defined as the serial repetition of tissue pattern along the axis of the body and allows differentiation of the developing organism. This differentiation in particular is mediated through Hox Genes. This essay will discuss their role and possible mechanisms for how they work. What are the hox genes? The hox genes are a set of genes that determine a segments identity. In the human there are 4 sets of 13 genes. These contain a homeobox domain which allows them to trigger the expression of various genes throughout the tissue. The exact nature of their expression is unknown however their role in patterning can be shown throughout various experiments. Experiments in flies The hox genes were originally discovered in the drosophila by Edward B lewis when he noticed that in some mutant drosphila some segments took the identity of segments above them. For example the drosophila expressed a pair of wings where it should have expressed ...