Growth factors in Drosophila: Characterization of two novel families of growth factors, IDGFs and ADGFs

IDGFs = Imaginal Disc Growth Factors secreted glycoproteins isolated from conditioned medium, where they are abundantly secreted by various Drosophila cell lines exhibiting macrophage properties (Cl8+, S2, Kc) (Kirkpatrick et al. 1995, Kawamura et al. 1999) Detection of DS47 secreted by Dm cell lines 1 - M3 media + serum 2 - supernatant from S2 culture, serum-free 3 - supernatant from S2 culture, serum+ 4 - supernatant from KcO culture, serum-free 5 - supernatant from culture, serum+ 6 - supernatant from M culture, serum+ 7 - supernatant from Ox736-3 M culture, serum+ 8 - supernatant from culture, serum+ 9 - supernatant from culture, serum+

Idgf genes in Drosophila melanogaster ~ 55 % seq. similarity at cDNA level ~ % seq. similarity at aa level

IDGF = Imaginal Disc Growth Factors IDGF proteins in cooperation with insulin are able to stimulate proliferation, polarization and motility of Cl8+ cells in culture (Kawamura et al.1999 – recombinant IDGF1 and 2) Cl8+ in CM

Human homolog HC-gp39 stimulate proliferation of fibroblasts and synovial cells in culture (Recklies et al.2002) in vivo is connected with differentiation of peripheral macrophages (Kirkpatick et al. 2007) is highly expressed in human body during inflammation (autoimmunity deseases like arthritis, final stage of cancer, viral infections)

IDGFs probably act as lectins binding domain is slighly modified Do they bind chitin or different oligosaccharide motive? A – IDGF2 binding domain B – Chitinase A binding domain C – Ym1 binding domain (murine homolog of insect IDGFs) Varela et al. 2002

IDGFs can be specialized to different function Western blot (Bryant and Zurovec) 2 main groups: IDGFs with constitutive and induced expression

IDGFs 1-3 were identified as a part of Drosophila immune response IDGFs 1-3 were identified as a part of Drosophila immune response (DeGregorio et al. 2001, 2002, Irving et al. 2001, Levy et al. 2004,…) various MA and proteomic analysis identified IDGF 1-3 as a part of Drosophila immune response in both larvae and adults IDGF 1 and 3 are induced with septic injury IDGF3 expression is affected with Toll and Imd pathway, however IDGF1 expression is independent on both of them. IDGF2 expression is upregulated early after Gram-positive bacterial infection as well as after infection with yeasts. All IDGFs were found as a part of haemolymphal clots

ADA-RELATED GENES IN DROSOPHILA

The effect of recombinant ADGF-A on the growth and morphology of the Cl.8 + imaginal disc cells Dying cells Living cells

It is possible to mimic the effect of ADGFA on cell growth by removal of adenosine The mutant ADGF has no effect

Expression of different ADGFs ADGF-A is expressed in embryo, larva and adult (arrows)

Gene targeting by homologous recombination

Mutagenesis of the gene ADGF-A WT The ADGFA mutant A rescue construct Stop kódón

Tests for somatic mutagenesis in Drosophila based on a recessive mutation in a marker gene (left), or a mutant tumor suppressor gene (right) y = yellow, yellow bristles instead of black normal ones; wts = warts, warts-like patches of overgrown tissue Heterozygous wild type cells at four-chromatide stage Mutagen Tumor cell Normal cell Clone with yellow bristles Tumorous clone Wild type homozygous clone Surrounding heterozygous tissue, phenotypically normal