Quiz 23: Genomics II: Functional Genomics, Proteomics, and Bioinformatics
The fertilized egg develops into an adult organism through four types of processes like - cell division, migration of the cells, cell differentiation and cell death. The growth of the cell occurs by cell division. Migration of the cells occurs during the embryonic development to organize the cells and germ layers. Cell differentiation is necessary to produce several types of cells to perform a specific function. Cell death is needed for construction of certain structures. Cell death is much needed during embryonic development of mammals; to form fingers of the hand, as hand is oval and flattened structure initially, cell death occurs between the regions of fingers.
In the cloned Bicoid protein injected in to the posterior end of zygote then the embryo would develop with 2 anterior ends. This is because Bicoid protein has key role in the formation of anterior portions of embryo. It would be difficult to predict the result of injection of Bicoid protein at later stages of development. As the genetic hierarchy had established already, the effects of introduction of Bicoid protein may be diminished. During the later stages of the development, the embryo undergoes divisions to form different types of cells and hence the injection of Bicoid protein may affect only a small areA.
Both Drosophila and Caenorhabditis elegans are well studied organisms to understand the developmental genetics extensively. Drosophila is advantageous because researchers could identify more mutant alleles involved in the alteration of development in a particular pattern. The hierarchy of gene regulation is studied extensively and understood well in the fruit fly. Caenorhabditis elegans is also advantageous for its simplicity and vast knowledge about cell fate. The researchers able to explore the timing of the gene expression, which is very critical factor in the developmental process. In animals, the development starts with an egg cell and then development of antero-posterior and dorso-ventral axes takes place. That adult organism is developed by the expansion of embryonic body plan. In plants, growth primarily initiated by-shoot and root meristems. At cellular level, development of plants is different, which does not involve cell migration. Many of the plant cells are totipotent. Development of animals requires specific organization within an oocyte and at the genetic level development of both animals and plants is similar due to involvement of genetic hierarchy of transcription factors that regulate the formation and expression of cells specialization.