A new Dictyostelium prestalk cell sub-type

Yoko Yamada, Robert R. Kay, Gareth Bloomfield, Susan Ross, Alasdair Ivens, Jeffrey G. Williams

    Research output: Contribution to journalArticle

    21 Citations (Scopus)

    Abstract

    The mature fruiting body of Dictyostelium consists of stalk and spore cells but its construction, and the migration of the preceding slug stage, requires a number of specialized sub-types of prestalk cell whose nature and function are not well understood. The prototypic prestalk-specific gene, ecmA, is inducible by the polyketide DIF-1 in a monolayer assay and requires the DimB and MybE transcription factors for full inducibility. We perform genome-wide microarray analyses, on parental, mybE- and dimB- cells, and identify many additional genes that depend on MybE and DimB for their DIF-1 inducibility. Surprisingly, an even larger number ofgenes are only DIF inducible in mybE- cells, some genes are only inducible in DimB- cells and some are inducible when either transcription factor is absent. Thus in assay conditions where MybE and DimB function as inducers of ecmA these genes fall under negative control by the same two transcription factors. We have studied in detail rtaA, one of the MybE and DimB repressed genes. One especially enigmatic group of prestalk cells is the anterior-like cells (ALCs). which exist intermingled with prespore cells in the slug. A promoter fusion reporter gene, rtaA:gal(u), is expressed in a subset of the ALCs that is distinct from the ALC population detected by a reporter construct containing ecmA and ecmB promoter fragments. At culmination, when the ALC sort out from the prespore cells and differentiate to form three ancillary stalk cell structures: the upper cup, the lower cup and the outer basal disk, the rtaA:gal(u) expressing cells preferentially populate the upper cup region. This fact, and their virtual absence from the anterior and posterior regions of the slug, identifies them as a new prestalk sub-type: the pstU cells. PstU cell differentiation is, as expected, increased in a dimB- mutant during normal development but, surprisingly, they differentiate normally in a mutant lacking DIF. Thus genetic removal of MybE or DimB reveals an alternate DIF-1 activation pathway, for pstU differentiation, that functions under monolayer assay conditions but that is not essential during multicellular development. (C) 2010 Elsevier Inc. All rights reserved.

    Original languageEnglish
    Pages (from-to)390-397
    Number of pages8
    JournalDevelopmental Biology
    Volume339
    Issue number2
    DOIs
    Publication statusPublished - 15 Mar 2010

    Keywords

    • Dictyostelium
    • DimB
    • MybE
    • DIF-1
    • Cell type differentiation
    • Prestalk
    • Anterior-like cells
    • Protein tyrosine phosphatase
    • Transcription factor
    • Gene expression
    • Basal disc
    • Culmination
    • Discoideum
    • Fate
    • Differentiation

    Cite this

    Yamada, Y., Kay, R. R., Bloomfield, G., Ross, S., Ivens, A., & Williams, J. G. (2010). A new Dictyostelium prestalk cell sub-type. Developmental Biology, 339(2), 390-397. https://doi.org/10.1016/j.ydbio.2009.12.045