Elsevier

Differentiation

Volume 70, Issue 1, March 2002, Pages 23-35
Differentiation

ORIGINAL ARTICLE
A gene encoding a novel anti-adhesive protein is expressed in growing cells and restricted to anterior-like cells during development of Dictyostelium

https://doi.org/10.1046/j.1432-0436.2002.700103.xGet rights and content

Abstract

The Dictyostelium gene ampA, initially identified by the D11 cDNA, encodes a novel anti-adhesive-like protein. The ampA gene product inhibits premature cell agglutination during growth and modulates cell–cell and cell–substrate adhesion during development. Analysis of the promoter indicates that cap site-proximal sequence directs ampA expression during both growth and early development. Expression following tip formation is controlled by more distal sequence, which contains TTGA repeats known to regulate prestalk cell gene expression in other promoters. Comparison of reporter gene expression and endogenous mRNA accumulation indicates that during growth the ampA gene is expressed in an increasing number of cells as a function of density. The number of cells expressing the ampA gene drops as development initiates, but the cells that continue to express the gene do so at high levels. These cells are initially scattered throughout the entire aggregate. By the tip formation stage, however, the majority of ampA-expressing cells are localized to the mound periphery, with only a few cells remaining scattered in the upper portion of the mound. In the final culminant, ampA is expressed only in the upper cup, lower cup, and basal disc. Although reporter expression is observed in cells that migrate anteriorly to a banded region just posterior to the tip, expression is rarely observed in the extreme tip. AmpA protein however, is localized to the tip as well as to ALCs during late development. The results presented here suggest that ampA gene expression is shut off in ALCs that continue along the prestalk differentiation pathway before they are added to the primordial stalk.

References (48)

  • R.R. Kay et al.

    DIF signalling and cell fate

    Sem Cell Dev Biol

    (1999)
  • M. Meima et al.

    Dictyostelium development – Socializing through cAMP

    Sem Cell Dev Biol

    (1999)
  • S. Mohanty et al.

    Control of spatial patterning and cell-type proportioning in Dictyostelium

    Sem Cell Dev Biol

    (1999)
  • M. Oyama et al.

    Changes during differentiation in requirements for cAMP for expression of cell-type-specific mRNAs in the cellular slime mold Dictyostelium discoideum

    Dev Biol

    (1986)
  • M. Oyama et al.

    Cyclic AMP and NH3/NH4+ both regulate cell-type-specific mRNA accumulation in the cellular slime mold Dictyostelium discoideum

    Dev Biol

    (1986)
  • A. Rathi et al.

    Expression of early developmental genes in Dictyostelium discoideum is initiated during exponential growth by an autocrine-dependent mechanism

    Mech Devel

    (1992)
  • J. Schindler et al.

    Ammonia determines the choice of morphogenetic pathways in Dictyostelium discoideum

    J Mol Biol

    (1977)
  • G. Shaulsky et al.

    Initial cell type divergence in Dictyostelium is independent of DIF-1

    Dev Biol

    (1996)
  • J. Sternfeld et al.

    Cell sorting during pattern formation in Dictyostelium

    Differentiation

    (1981)
  • J. Sternfeld et al.

    Fate and regulation of anterior-like cells in Dictyostelium slugs

    Dev Biol

    (1982)
  • M. Sussman

    Cultivation and synchronous morphogenesis of Dictyostelium under controlled experimental conditions

  • G. Weeks et al.

    The Dictyostelium cell cycle and its relationship to differentiation. (Minireview)

    FEMS Microbiol Lett

    (1994)
  • E. Barklis et al.

    Structure of the Dictyostelium discoideum prestalk D11 gene and protein

    Mol Cell Biol

    (1985)
  • M. Clarke et al.

    PSF and CMF, autocrine factors that regulate gene expression during growth and early development of Dictyostelium

    Experientia

    (1995)
  • Cited by (0)

    View full text