Gene of the development

The genes of the development are Gène S which make it possible to build a specific organization starting from the Zygote (or cell-egg).

One distinguishes several types of genes of the development:

the genes for maternal purpose which are transcribed during the Ovogénèse in the Ovocyte (or in accompanying cells like the feeder cells at the Drosophile) and whose products (ARNm or proteins) are stored in precise areas of the Ovocyte. After the Fecundation, these ARNm or these proteins determine the installation of the axes of polarity of the embryo before this one does not express its own genome.

Exemple: the gene Bicoid at the Drosophile is stored in the form of ARNm in the ovocyte in what will correspond to the future former area of the embryo. The embryos resulting from ovocytes without bicoid do not have former areas (not head nor of thorax).

genes expressed starting from the genome of the embryo.

One can also distinguish:

Of the genes which specify a polarity or information of position. For example, the gene Cerberus at the Xénope determines the area of the head. Some of these genes are Morphogène S, i.e. the corresponding proteins form gradients of concentration and specify different cellular types according to their concentrations. For example, the gene Dpp of the Drosophila and its counterpart BMP at the Vertébré S specify different cellular types along the dorso-ventral axis.
Of the genes which determine a particular cellular chalk-lining. For example the factors of transcription MyoD and Myf5 determine skeletal muscular cells striated in the embryo, some is their position. These genes control genes of Différenciation, which allow the formation of a cellular type particular.

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