Insect Growth factors
During animal development the growth of different tissues and organs is finely controlled by signals originating both within the developing structure and outside it. The intrinsic controls of tissue growth are often intimately connected with the mechanisms controlling the development of a covert or overt pattern of differentiation within the cell population (Bryant, P.J. & Simpson, P., 1984). For example, the Dpp and Wg signal transduction pathways in imaginal discs are required for normal cell proliferation as well as for the control of the developing pattern (Diaz-Benjumea, F.J., Cohen, B. & Cohen, S.M., 1994). Extrinsic factors controlling tissue growth include hormones and polypeptide growth factors that are released in a regulated fashion either from central endocrine organs or from diffuse sources, and these often have tissue-specific functions. Extrinsic control of tissue growth is a familiar concept in mammals, where the main signals are growth hormone, insulin-like growth factors, and other polypeptide growth factors (Cross, M. & Dexter, T. M. 1991). However, it is a relatively unexplored area of investigation in Drosophila and other insects.
We are developing approaches to the investigation of extrinsic controls on tissue growth by using the imaginal discs of Drosophila as a model system. As it is shown in the Figure below, the Cl8+ cells undergo dramatic morphological change when transferred to the serum free media, and undergo apoptosis. The addition of growth factors can rescue the cells. This work has already led to the identification of two families of secreted growth factors: the imaginal disk growth factors (IDGFs) (Kawamura, K. , Shibata, T. , Saget, O. , Peel, D. & Bryant, P. J., 1999), which are related to chitinases, and the adenosine deaminase-related growth factors (ADGFs), which have adenosine deaminase enzymatic activity (Žurovec M, Dolezal T, Gazi M, Pavlova E & Bryant, 2002)
During animal development the growth of different tissues and organs is finely controlled by signals originating both within the developing structure and outside it. The intrinsic controls of tissue growth are often intimately connected with the mechanisms controlling the development of a covert or overt pattern of differentiation within the cell population (Bryant, P.J. & Simpson, P., 1984). For example, the Dpp and Wg signal transduction pathways in imaginal discs are required for normal cell proliferation as well as for the control of the developing pattern (Diaz-Benjumea, F.J., Cohen, B. & Cohen, S.M., 1994). Extrinsic factors controlling tissue growth include hormones and polypeptide growth factors that are released in a regulated fashion either from central endocrine organs or from diffuse sources, and these often have tissue-specific functions. Extrinsic control of tissue growth is a familiar concept in mammals, where the main signals are growth hormone, insulin-like growth factors, and other polypeptide growth factors (Cross, M. & Dexter, T. M. 1991). However, it is a relatively unexplored area of investigation in Drosophila and other insects.
We are developing approaches to the investigation of extrinsic controls on tissue growth by using the imaginal discs of Drosophila as a model system. As it is shown in the Figure below, the Cl8+ cells undergo dramatic morphological change when transferred to the serum free media, and undergo apoptosis. The addition of growth factors can rescue the cells. This work has already led to the identification of two families of secreted growth factors: the imaginal disk growth factors (IDGFs) (Kawamura, K. , Shibata, T. , Saget, O. , Peel, D. & Bryant, P. J., 1999), which are related to chitinases, and the adenosine deaminase-related growth factors (ADGFs), which have adenosine deaminase enzymatic activity (Žurovec M, Dolezal T, Gazi M, Pavlova E & Bryant, 2002)