morphogen การใช้

• This method involves the action of morphogen gradients within the syncytium.
• Changes in these morphogen gradients may also affect the leaf form.
• Discrete target genes respond to different thresholds of morphogen activity.
• Bicoid functions as a graded morphogen transcription factor that localizes to the nucleus.
• The Bicoid protein is a morphogen as well.
• Beta-catenin also acts as a morphogen in later stages of embryonic development.
• During early development, morphogen gradients generate different cell types in distinct spatial order.
• Similar to bicoid, nanos is localized to the posterior pole as a graded morphogen.
• Turing suggested that there could be feedback control of the production of the morphogen itself.
• A morphogen spreads from a localized source and forms a concentration gradient across a developing tissue.
• This could cause continuous fluctuations in the amount of morphogen as it diffused around the body.
• In this context Shh acts as a morphogen-it induces cell differentiation dependent on its concentration.
• There also exist different morphogen gradients in a developing leaf which define the leaf's axis.
• During early development, morphogen gradients result in the differentiation of specific cell types in a distinct spatial order.
• If the morphogen is present everywhere, the result is an even pigmentation, as in a black leopard.
• Dpp diffuses from this stripe towards the edges of the tissue, forming a gradient as expected of a morphogen.
• In addition it serves for long-range transport of hydrophobic intercellular messengers, like the morphogen Indian hedgehog ( protein ).
• 7 ) Each cell has to be able to  read the morphogen concentration accurately, otherwise boundaries between tissues become ragged.
• More specifically, a morphogen is a signaling molecule that acts directly on cells to produce specific cellular responses depending on its local concentration.
• Thus, cells far from the source of the morphogen will receive low levels of morphogen and express only low-threshold target genes.