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Sorrentino, R.P., Melk, J.P., Govind, S. (2004). Genetic analysis of contributions of dorsal group and JAK-Stat92E pathway genes to larval hemocyte concentration and the egg encapsulation response in Drosophila.  Genetics 166(3): 1343--1356.
FlyBase ID
FBrf0174690
Publication Type
Research paper
Abstract
Drosophila larvae defend themselves against parasitoid wasps by completely surrounding the egg with layers of specialized hemocytes called lamellocytes. Similar capsules of lamellocytes, called melanotic capsules, are also formed around "self" tissues in larvae carrying gain-of-function mutations in Toll and hopscotch. Constitutive differentiation of lamellocytes in larvae carrying these mutations is accompanied by high concentrations of plasmatocytes, the major hemocyte class in uninfected control larvae. The relative contributions of hemocyte concentration vs. lamellocyte differentiation to wasp egg encapsulation are not known. To address this question, we used Leptopilina boulardi to infect more than a dozen strains of host larvae harboring a wide range of hemocyte densities. We report a significant correlation between hemocyte concentration and encapsulation capacity among wild-type larvae and larvae heterozygous for mutations in the Hopscotch-Stat92E and Toll-Dorsal pathways. Larvae carrying loss-of-function mutations in Hopscotch, Stat92E, or dorsal group genes exhibit significant reduction in encapsulation capacity. Larvae carrying loss-of-function mutations in dorsal group genes (including Toll and tube) have reduced hemocyte concentrations, whereas larvae deficient in Hopscotch-Stat92E signaling do not. Surprisingly, unlike hopscotch mutants, Toll and tube mutants are not compromised in their ability to generate lamellocytes. Our results suggest that circulating hemocyte concentration and lamellocyte differentiation constitute two distinct physiological requirements of wasp egg encapsulation and Toll and Hopscotch proteins serve distinct roles in this process.
PubMed ID
PubMed Central ID
PMC1470785 (PMC) (EuropePMC)
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Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    Genetics
    Title
    Genetics
    Publication Year
    1916-
    ISBN/ISSN
    0016-6731
    Data From Reference
    Aberrations (2)
    Alleles (20)
    Genes (14)
    Insertions (1)