Two types of Drosophila R7 photoreceptor cells are arranged randomly

A model for stochastic cell-fate determination

Melanie L Bell, James B. Earl, Steven G. Britt

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

The R7 photoreceptor cells of the Drosophila retina are ultraviolet sensitive and are thought to mediate color discrimination and polarized light detection. In addition, there is growing evidence that the color sensitivity of the R8 cell within an individual ommatidium is regulated by a genetic switch that depends on the type of R7 cell adjacent to it. Here we examine the organization of the two major types of R7 cells by three different rigorous statistical methods and present evidence that they are arranged randomly and independently. First, we performed L-function analyses to test whether the organization of R7 cells (and the relationship between them) is regular, clustered, or completely spatially random. Next, we used generalized linear mixed models to test whether the proportion of R7 cell neighbors differs from their prevalence within the eye as a whole. Finally, we conducted a series of simulations to test whether the proportion of R7 cell neighbors differs from that in a random simulation. In each case, we found evidence that the organization of the two types of R7 cells is random and independent, suggesting that R7 cells in neighboring ommatidia are unlikely to interact and influence each other's identity and may be determined stochastically in a cell-autonomous manner. Compared with traditional lineage or inductive mechanisms, this may represent a novel mechanism of cell fate determination based on noisy or stochastic gene expression in which the differentiation of an individual R7 cell is a random event but the proportions of R7 cell subtypes are regulated.

Original languageEnglish (US)
Pages (from-to)75-85
Number of pages11
JournalJournal of Comparative Neurology
Volume502
Issue number1
DOIs
StatePublished - May 1 2007
Externally publishedYes

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Photoreceptor Cells
Drosophila
Color
Retina
Linear Models

Keywords

  • Cell fate determination
  • Development
  • Differentiation
  • Drosophila melanogaster
  • Photoreceptor
  • Random
  • Replicated bivariate point pattern
  • Retina
  • Rhodopsin
  • Spatial point pattern
  • Stochastic

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Two types of Drosophila R7 photoreceptor cells are arranged randomly : A model for stochastic cell-fate determination. / Bell, Melanie L; Earl, James B.; Britt, Steven G.

In: Journal of Comparative Neurology, Vol. 502, No. 1, 01.05.2007, p. 75-85.

Research output: Contribution to journalArticle

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