title: Two Independent Functions of Collier/Early B Cell Factor in the Control of Drosophila Blood Cell Homeostasis.
abstract: Blood cell production in the Drosophila hematopoietic organ, the lymph gland, is controlled by intrinsic factors and extrinsic signals. Initial analysis of Collier/Early B Cell Factor function in the lymph gland revealed the role of the Posterior Signaling Center (PSC) in mounting a dedicated cellular immune response to wasp parasitism. Further, premature blood cell differentiation when PSC specification or signaling was impaired, led to assigning the PSC a role equivalent to the vertebrate hematopoietic niche. We report here that Collier is expressed in a core population of lymph gland progenitors and cell autonomously maintains this population. The PSC contributes to lymph gland homeostasis by regulating blood cell differentiation, rather than by maintaining core progenitors. In addition to PSC signaling, switching off Collier expression in progenitors is required for efficient immune response to parasitism. Our data show that two independent sites of Collier/Early B Cell Factor expression, hematopoietic progenitors and the PSC, achieve control of hematopoiesis.
authors: Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), University Paul Sabatier (UPS), CNRS, 118 Route de Narbonne 31062 Toulouse cedex 09, France.
authors: Justine
authors: J
authors: Oyallon
authors: Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), University Paul Sabatier (UPS), CNRS, 118 Route de Narbonne 31062 Toulouse cedex 09, France.
authors: Nathalie
authors: N
authors: Vanzo
authors: Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), University Paul Sabatier (UPS), CNRS, 118 Route de Narbonne 31062 Toulouse cedex 09, France.
authors: Joanna
authors: J
authors: Krzemień
authors: Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), University Paul Sabatier (UPS), CNRS, 118 Route de Narbonne 31062 Toulouse cedex 09, France.
authors: Ismaël
authors: I
authors: Morin-Poulard
authors: Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), University Paul Sabatier (UPS), CNRS, 118 Route de Narbonne 31062 Toulouse cedex 09, France.
authors: Alain
authors: A
authors: Vincent
authors: Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), University Paul Sabatier (UPS), CNRS, 118 Route de Narbonne 31062 Toulouse cedex 09, France.
authors: Michèle
authors: M
authors: Crozatier
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006410:Hematopoiesis; D006434:Hemocytes / Q000166:cytology*; D006706:Homeostasis; D006790:Host-Parasite Interactions; D007107:Immune System; D017403:In Situ Hybridization; D008196:Lymph / Q000502:physiology*; D008938:Mitosis; D034622:RNA Interference; D015398:Signal Transduction; D055153:Stem Cell Niche; D013234:Stem Cells; D014157:Transcription Factors / Q000378:metabolism*; D014863:Wasps
chemical_list: D029721:Drosophila Proteins; D014157:Transcription Factors; C104357:kn protein, Drosophila; D049452:Green Fluorescent Proteins