Department of Zoology

Principal Investigators

Research area - Developmental Biology

Our laboratory is composed of scientists carrying out academic research on the development and evolution of the patterns of sensory bristles in insects.

We aim to understand the genetic control of the spatial organisation of bristle patterns in insects. On the notum of Drosophila there is a stereotyped array of eleven large sensory bristles. Sensory bristle development requires the activity of the achaete-scute genes whose products are bHLH-type transcription factors the expression of which confers neural potential to cells. The bristle pattern arises as the result of achaete-scute expression in clusters of cells at the site of each future bristle. These genes share cis-regulatory controlling sequences, called enhancers, that respond to local positional cues and regulate the complex spatial and temporal expression patterns of these genes. Two upstream activators, Pannier and Iroquois, bind to the enhancer sequences and regulate achaete-scute expression.

There are many thousands of species of Diptera, however, and many of these have bristle patterns that differ from Drosophila but are equally stereotyped. The question therefore arises as to how all of these different patterns are made and to what extent the basic genetic mechanisms described in Drosophila have been conserved. To study this we are using molecular and genetic approaches to study the conservation of the structure and function of achaete-scute homologues and their upstream regulators in a number of species of Diptera.

Research group - Skylab

Selected publications

• Renaud, O. and Simpson, P (2001) scabrous modifies epithelial cell adhesion and extends the range of lateral signalling during development of the spaced bristle pattern in Drosophila. Developmental Biology, 240: 361-376.
• Pistillo, D., Skaer, N. and Simpson, P (2002) scute expression in Calliphora vicina reveals an ancestral pattern of longitudinal stripes on the thorax of higher Diptera. Development, 129: 563-572.
• Nick Skaer, Daniela Pistillo, Jean-Michel Gibert, Pietro Lio, Corinna Wülbeck, and Pat Simpson (2002) Gene duplication at the achaete-scute complex and morphological complexity of the peripheral nervous system in Diptera. Trends in Genetics 18: 399-405.
• Corinna Wülbeck and Pat Simpson (2002) The expression of pannier and achaete-scute homologues in a mosquito suggests an ancient role of pannier as a selector gene in the regulation of the dorsal body pattern. Development, 129: 3861-3871.
• Olivier Renaud and Pat Simpson (2002) Movement of bristle precursors contributes to the spacing pattern in Drosophila. Mech of Dev 119: 201-211.
• Nick Skaer, Daniela Pistillo and Pat Simpson (2002) Transcriptional heterochrony of scute and changes in bristle pattern between two closely related species of blowfly. Developmental Biology 252: 31-45.
• Pat Simpson (2002) Evolution of development in closely related species of flies and of worms. Nat. Rev. Genet. 3: 907-17.
• Kazuya Usui, Daniela Pistillo and Pat Simpson (2004) Mutual exclusion of sensory bristles and tendons on the notum of Dipteran flies. Current Biology 14: 1047-1055.
• Akiko Usui-Ishihara and Pat Simpson (2005) Differences in sensory projections between macro- and microchaetes in Drosophilid flies. Developmental Biology 277: 170-183.
• Sylvain Marcellini, Jean-Michel Gibert and Pat Simpson (2005) achaete, but not scute, is dispensable for the peripheral nervous system of Drosophila . Developmental Biology 285:545-553.
• Jean-Michel Gibert, Sylvain Marcellini, Jean R. David Christian Schlötterer and Pat Simpson (2005). A major bristle QTL from a selected population of Drosophila uncovers the zinc-finger transcription factor Poils-au-dos, a repressor of achaete-scute. Developmental Biology 288: 194-205.
• Joanna Richardson and Pat Simpson (2006) A conserved trans-regulatory landscape for scute expression on the notum of cyclorraphous Diptera. Development, Genes & Evolution 216:29-38.
• Pat Simpson and Sylvain Marcellini (2006) The origin and evolution of stereotyped patterns of macrochaetes on the nota of cyclorraphous Diptera. Heredity, 97:148-156.
• Sylvain Marcellini and Pat Simpson (2006) Two or four bristles: Functional evolution of an enhancer of scute in drosophilids. PloS Biology, 4:e386.
• Pat Simpson (2007) The stars and stripes of animal bodies: evolution of regulatory elements mediating pigment and bristle patterns in Drosophila. Trends in Genetics, 23: 350-358.
• Savita Ayyar, Daniela Pistillo, Manuel Calleja, Anna Brookfield, Kelly Gittins, Claire Goldstone, and Pat Simpson (2007) NF-B/Rel-mediated regulation of the neural fate in Drosophila. PloS One 11: e1178.