Contact: Miall 8.22, +44(0) 113 34 32822,
You can read more about Dr Peel's interests here:
Evolutionary Developmental Biology in Animals
I am interested in how animal evolution occurs at different levels of biological complexity; i.e. genetic, cellular, organismal and ecological. My research efforts to date have focused on understanding how diversity in animal body plans evolved. Animals obtain their species-specific morphological characteristics during embryonic development and/or metamorphosis. My work therefore compares the genetic and cellular mechanisms controlling embryogenesis in different animal species in order to identify the molecular changes that underpinned divergence in animal body plans during evolution.
The red flour beetle Tribolium castaneum
My research currently focuses on a laboratory model insect species, the red flour beetle Tribolium castaneum. This is a holometabolous insect species, meaning that it exhibits 'complete metamorphosis', passing from larva to adult via a pupal stage. I study Tribolium because it is becoming increasing amenable to genetic manipulation in the laboratory and has retained a number of interesting ancestral developmental traits, such as the sequential formation of body segments during embryogenesis.
The evolution of segmentation mechanisms in holometabolous insects
One of the aims of my work is to provide important insights into how developmental gene networks evolve. This can be achieved by gaining a deep understanding of the developmental genetic mechanisms operating in Tribolium, and identifying how these are similar or different to the development genetic mechanisms operating in other holometabolous insect species; e.g. the parasitic wasp Nasonia vitripennis, the honeybee Apis mellifera, the moths Bombyx mori and Manduca sexta, and the fruit fly Drosophila melanogaster (see Peel, 2008. Philos. Trans. R. Soc. Lond. B. Biol. Sci.). I am particularly interested in using comparative developmental biology to understand how the gene networks controlling body segment formation have evolved (see Peel, Chipman & Akam, 2005. Nat. Rev. Genet.). Ancestrally, insects developed their trunk segments sequentially, in an anterior-to-posterior progression. This developmental trait is found in more primitive, non-holometabolous, insect species, such as grasshoppers and true bugs, as well as non-insect arthropods such as centipedes and spiders. The beetle Tribolium is an example of a holometabolous insect species that has also retained this ancestral trait during evolution. However, many other holometaoblous insects, including Nasonia, Apis and Drosophila, have evolved a faster mode of development in which all body segments form more-or-less simultaneously. By studying the genetic and cellular mechanisms underlying Tribolium body segment specification I explore how this evolutionary transition from sequential to simultaneous segmentation might have occurred.
The origin and evolution of segmentation mechanisms in animals
I also make comparisons between much more distantly related animals. My recent work has helped to prove that the genetic developmental mechanism controlling the formation of body segments in Tribolium shows striking similarities to the developmental mechanism that gives rise to repeated internal body structures in humans, such as our vertebrate/ribs and their associated muscle (see Sarrazin*, Peel* & Averof, 2012. Science). Segmented structures in arthropods and vertebrates both form under the control of a 'segmentation clock' gene network. I am currently investigating whether the arthropod and vertebrate segmentation clocks are sufficiently similar at the genetic level to suggest that they were both inherited from the common ancestor of arthropods and vertebrates. This ancestral animal lived over 550 million years ago. The alternative possibility is that arthropod and vertebrate segmentation clocks represent an interesting case of parallel evolution, in which similar gene networks have evolved, or been recruited, independently, to pattern reiterated morphological structures. Either way, my work promises to offer important insights into some of the earliest events in the evolution of animal developmental mechanisms.
Flour beetles are also a classical laboratory model system for studying intra- and interspecific ecological interactions, and among many significant beetle pests of stored food products. In collaboration with other members of the School of Biology I am currently developing a number of projects investigating the genetic factors that influence Tribolium behaviour and community ecology, with a view to improving beetle pest management and understanding the factors involved in the maintenance of species diversity.
Rahul Sharma (Research Fellow - BBSRC)
Matthew Dooley (BBSRC/Fera PhD student; Oct 2014 - Sept 2018)
Peter Harrison (BBSRC PhD student; Oct 2014 - Sept 2018)
Information about available PhD projects can be found via the following links:
Description of Images:
Top panel: Tribolium castaneum oogenesis and early embryonic development.
From left-to-right:  Tribolium ovariole showing oocytes (unlaid eggs) at different stages of development; taken from a transgenic beetle in which nuclear localized green-fluorescent protein (nGFP) is ubiquitously expressed (green). Acetylated tubulin is stained red.  Tribolium terminal oocyte, now filled with yoke, and almost ready to be laid – green and red show the same as in . Note the asymmetric position of the oocyte nucleus – its migration to one side of the oocyte helps set the ventral-dorsal (front-to-back) body axis (see Lynch et al., 2010).  View down on the anterior pole of a recently laid (1-2 hours old) Tribolium egg showing anteriorly localized mRNA of the gene Tc-pangolin (red) associated with a cortical microtubule network (green) (see Peel & Averof, 2010).  A mitotic wave sweeping across a Tribolium blastoderm embryo (from bottom left to top right). Note the leakage of nGFP (green) when the nuclear envelope (red) breaks down prior to mitosis.  An early germband embryo, with nuclear membranes stained red, at the beginning of axis elongation and the formation of abdominal segments. The developing head lobes are at the top.
Middle panel: Developmental gene expression in Drosophila and Tribolium embryos.
From left-to-right:  Early Tribolium germband embryo showing expression of two genes (Tc-even-skipped and Tc-odd-skipped) involved in segment formation that are expressed out-of-phase with one another (see Sarrazin et al., 2012). . An elongating Tribolium embryo showing expression of the segmentation gene Tc-engrailed (blue) and the Hox gene Tc-Deformed (red) (see Peel et al., 2013). . Abdominal region of a Drosophila embryo showing expression of the engrailed-family genes engrailed (red) and invected (green) (see Peel et al., 2006). Nuclei are stained blue.  Anterior end of a fully extended Tribolium embryo showing expression of the segmentation gene Tc-engrailed (blue) and the head development gene Tc-collier (see Peel et al., 2013). . Drosophila blastoderm embryo showing expression of the segmentation gene fushi-tarazu (yellow). Nuclei are stained grey.
Bottom panel: Oscillating segmentation gene expression in Tribolium.
From left-to-right: [1-5] Embryos of increasing age showing germband elongation and dynamic expression of the segmentation gene Tc-odd-skipped. Expression of Tc-odd-skipped oscillates in the posterior most cells of the embryo (see Sarrazin et al., 2012).
Investigating the gene regulatory network underlying the segmentation clock of the flour beetle Tribolium castaneum (2015-2018). Funded by a BBSRC New Investigator Research Grant (BB/L020092/1)
Investigating the Arthropod Segmentation Clock that controls Sequential Segment Formation during Arthropod Development and its Potentially Ancient Evolutionary Origins (2013-2017). Funded by a Marie Curie CIG (PCIG12-GA-2012-333650).
BLGY2223 - Organismal Evolution
BLGY1124/1128 - The Diversity of Life/Living Planet
BLGY1128 - Living Planet
BLGY1304 - Research Experience and Skills Level 1
BLGY2100/2301 - Level 2 Tutorials
BLGY2223 - Organismal Evolution
BLGY2262 - Animal Developmental Biology
BLGY2301 - Research Experience and Skills Level 2
BLGY3021 - Research Project
BLGY3245 - Advanced Topics in Evolution
BLGY3251 - Animal Developmental Biology
BLGY3340 - Biology Research Projects
Member of Masters Taught Student Education Committee (Exams Officer: Biodiversity and Conservation)