The contribution of cell division to axis extension in insects

• Applicant: Matthew Benton, Ph.D.
• Subject Area: Evolutionary Cell and Developmental Biology (Zoology) ; Developmental Biology
• Term: from 2018 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 407643416

Most animal embryos extend/elongate along their anterior-posterior (head-tail) axis during development. In the preeminent insect model organism, the fruit fly Drosophila melanogaster, embryo extension is mainly driven by the rearrangement of existing cells, and takes place after most parts of the embryo have been specified by “patterning” genes. However, in many other insects, including the beetle Tribolium castaneum, embryo extension occurs at the same time as extensive cell divisions and tissue patterning. Therefore, in contrast to Drosophila, most insect embryos must coordinate cell rearrangements, cell divisions, and tissue patterning throughout embryo extension. Nothing is known about how this coordination is achieved, as descriptions of the relative timing of these three processes do not exist. In my project, I will quantify the amount and timing of cell division during embryo extension in Tribolium. I will also investigate the degree to which the cell divisions are oriented along the anterior-posterior axis, as oriented divisions would directly contribute to embryo extension. To achieve both of these goals, I will carry out high resolution fluorescent live imaging of Tribolium embryos and analyse the resulting data using automated or manual approaches. For the second aim of my project, I will collaborate with another lab member to investigate the functional role of a group of cell divisions that occur during Drosophila embryo extension. These divisions are oriented along the anterior-posterior axis, and, like in Tribolium, occur concurrently with tissue patterning and embryo extension. The third aim of my project is to discover how tissue patterning genes directly or indirectly regulate cell divisions during Tribolium embryo extension. To do this, I will examine the expression and function of candidate genes suggested by the Drosophila aspect of the project, and by existing publications. For the final part of my project, I will carry out a broad survey of cell divisions during embryo extension across different arthropod species. Together, the results of my project will reveal how cell divisions contribute to insect embryo extension, how these divisions are regulated, and whether stereotypic patterns of cell divisions during embryo extension are conserved across arthropods.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Host: Professor Michael Akam, Ph.D.