\"The graded nuclear location of the transcription factor Dorsal along the dorso
ID: 3166118 • Letter: #
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"The graded nuclear location of the transcription factor Dorsal along the dorsoventral axis of the early Drosophila embryo provides positional information for the determination of different cell fates. Nuclear uptake of Dorsal depends on a complex signalling pathway comprising two parts: an extracellular pro- teolytic cascade transmits the dorsoventral polarity of the egg chamber to the early embryo and gener- ates a gradient of active Spätzle protein, the ligand of the receptor Toll; an intracellular cascade down- stream of Toll relays this graded signal to embryonic nuclei. The slope of the Dorsal gradient is not deter- mined by diffusion of extracellular or intracellular components from a local source, but results from self-organised patterning, in which positive and neg- ative feedback is essential to create and maintain the ratio of key factors at different levels, thereby establishing and stabilising the graded spatial infor- mation for Dorsal nuclear uptake." Curr Biol 15:R887.
Article: http://www.cell.com/current-biology/fulltext/S0960-9822(05)01226-1
1. What are the two main properties of a morphogen?
Explanation / Answer
Q What are the two main properties of a morphogen
A morphogen is a substance whose non-uniform distribution controls the pattern of tissue development in the process of morphogenesis or pattern formation, morphogenesis is an important process of developmental biology, it gives rise to positions of different specialized cell types in a tissue or In other words a morphogen is a signaling molecule , which directly acts on cells to produce specific cellular responses depending on its local concentration.
Two important characteristic of morphogen are -
i)They show a graded distribution throughout a developmental field, due to this the value of concentration in a particular point of gradient corresponds to a particular position in that field.
ii) Different range of morphogen concentration shows different cell fates.
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