Biochemistry

Evolution and Development, Genome Evolution:

Genetic studies have helped us to understand the molecular control of development in a small number of model systems. In Drosophila melanogaster and Caenorhabditis elegans, for example, we can trace the molecular events that pattern specific body parts all the way back to the fertilised egg. What is unclear is how these patterning processes change over evolutionary time to give us the diversity of morphology we see in organisms today.

Our lab aims to understand the molecular basis of morphological evolution by studying how the developmental pathways that regulate embryogenesis evolve to produce different animal morphologies. To study this we use two model systems, the Honeybee (Apis mellifera) and a Rotifer (Brachionus plicatilis).

The Evolution of Developmental Pathways:

To understand and model the evolution of developmental pathways we need to study how evolutionary processes affect the complex interactions of genes and proteins that pattern embryos. One of the best model systems for understanding pattern formation is segmentation in the fruit fly Drosophila melanogaster. Twenty years of study of this system has lead to an almost complete understanding of how genes and their product produce the segments of Drosophila. We are studying how this system has evolved by looking at the same segmentation process in the Honeybee. Honeybee segmentation is homologous to segmentation in Drosophila, uses many of the same genes, but is different in its morphological and molecular details. Using RNAi and transgenic Drosophila we are trying to understand how these molecular and morphological changes have come about. This study should give us a better understanding of the way in which developmental processes evolved and will perhaps lead to a predictive theory of the evolution of development.

Deep Homology and the Evolution of Animals:

Little is known about the genetic control of development in animals other than the well-studied genetic model systems Drosophila, Caenorhabditis, Zebrafish and mouse. One group of animals that are poorly researched are the Lophotrochozoa, a group of animal phyla including annelids, molluscs, platyhelminths, rotifers and others. Without understanding how these animals regulate development we are unable to develop a clear picture of the evolutionary history of animals. To study the genetic control of development in the Lophotrochozoa we are using a Rotifer, Brachionus plicatilis, as a model system.
Rotifers are tiny aquatic animals that are easy to grow in the laboratory and have a short generation time. We have developed technique to examine gene expression and function and are using these to understand development in this animal.

These projects are funded by a Royal society of New Zealand Marsden Grant and a University of Otago Research Grant

Furthur Details of these projects and the Laboratory for Evolution and Development can be found on our website.

Publications:

Shigenobu, S., Bickel, R. D., Brisson, J. A., Butts, T., Chang, C.-c., Christiaens, O., Davis, G. K., Duncan, E. J., Ferrier, D. E. K., Iga, M., Janssen, R., Lin, G.-W., Lu, H.-L., McGregor, A. P., Miura, T., Smagghe, G., Smith, J. M., Zee, M. v. d., Velarde, R. A., Wilson, M. J., Dearden, P. K., Stern, D. L., 2010. Comprehensive survey of developmental genes in the pea aphid, Acyrthosiphon pisum: frequent lineage-specific duplications and losses of developmental genes. Insect Molecular Biology. 19, 47-62.

The International Aphid Genomics Consortium, 2010. Genome sequence of the pea aphid Acyrthosiphon pisum. PLoS Biol. 8, e1000313.

Wilson, M. J., Havler, M., Dearden, P. K., 2010. Giant, Kruppel, and caudal act as gap genes with extensive roles in patterning the honeybee embryo. Dev Biol. 339, 200-211

Wilson, M. J., Dearden, P. K., 2009. Tailless patterning functions are conserved in the honeybee even in the absence of Torso signaling. Dev Biol. 335, 276-87

Duncan EJ, Wilson MJ, Smith JM, Dearden PK (2008) Evolutionary origin and genomic organisation of runt-domain containing genes in arthropods. BMC Genomics;9(1):558

Specht D, Wu SB, Turner P, Dearden P, Koentgen F, Wolfrum U, Maw MA, Brandstaetter JH, Tom Dieck S (2008) .Effects of presynaptic mutations on a postsynaptic Cacna1s calcium channel co-localized with mGluR6 at mouse photoreceptor ribbon synapses.Invest Ophthalmol Vis Sci. 2008 Oct 24

M.J. Wilson and P.K. Dearden (2008). Evolution of the Insect Sox genes. BMC Evolutionary Biology, 8:120 doi:10.1186/1471-2148-8-120[

Julia M. Young, Jennifer L. Juengel, Kenneth G. Dodds, Mhairi Laird, Peter K. Dearden, Alan S. McNeilly, Kenneth P. McNatty, Theresa Wilson. (2008)The ALK6 Booroola mutation enhances suppressive effects of BMP2, -4, -6 and GDF9 on FSH release from ovine primary pituitary cell cultures. Journal of Endocrinology, 196(2):251-261

The Honeybee genome sequencing consortium (Includes P.K Dearden and M.J. Wilson) (2006) Insights into social insects from the genome of the honey bee Apis mellifera. Nature, 443. 931-949

P.K. Dearden, M.J. Wilson, L. Sablan, P.W. Osborne, M. Havler,E. McNaughton, K. Kimura, N Milshina, M. Hasselmann, T. Gempe, M. Schioett, S.J. Brown, C. Elsik, P.W.H Holland, T. Kadowaki, M. Beye. (2006). Patterns of conservation and change in Honeybee developmental genes. Genome Research,16: 1376-1384.

Sabater-Munoz, B., F. Legeai, C. Rispe, J. Bonhomme, PK. Dearden, C. Dossat, A. Duclert, J. P. Gauthier, D. G. Ducray, W. Hunter, P. Dang, S. Kambhampati, D. Martinez-Torres, T. Cortes, A. Moya, A. Nakabachi, C. Philippe, N. Prunier-Leterme, Y. Rahbe, J. C. Simon, D. L. Stern, P. Wincker and D. Tagu (2006). "Large-scale gene discovery in the pea aphid Acyrthosiphon pisum (Hemiptera)." Genome Biol 7(3): R21.

Dearden PK (2006) Germ cell development in the Honeybee (Apis mellifera); vasa and nanos expression, BMC Developmental Biology 6, 6 DOI:10.1186/1471-213X-6-6.

B. Sabater-Munoz, F. Legeai, C. Rispe, J. Bonhomme, P. K. Dearden, C. Dossat, A. Duclert, J-P. Gauthier, D. G. Ducray, W. Hunter, P. Dang, S. Kambhampati, D. Martinez-Torres, T. Cortes, A. Moya, A. Nakabachi, C. Philippe, N. Prunier-Leterme, Y. Rahbe, J-C. Simon, D. L. Stern, P. Wincker & D. Tagu. (2006) Large scale gene discovery in the pea aphid Acyrthosiphon pisum (Hemiptera). Genome Research. In Press.

A.Hemara-Wahanui , S. Berjukow , C. I. Hope , P.K. Dearden , S. Wu , J.Wilson-Wheeler, D.M. Sharp , P. Lundon-Treweek, G.M. Clover, J. Hoda, J. Striessnig, R. Marksteiner, S. Hering and M. A. Maw (2005) A CACNA1F mutation identified in an X-linked retinal disorder shifts the voltage-dependence of Cav1.4 channel activation. Proceedings of the National Academy of Sciences USA 102: 7553-7558.

P. Osborne, P.K. Dearden (2005) Expression of Pax Group III genes in the Honeybee (Apis mellifera). Development, Genes and Evolution. 215: 499-508.

P. Osborne, P.K. Dearden (2005) Non-radioactive in situ hybridisation to honeybee embryos and ovaries. Apidologie 36: 113-118.

M.J. Denton, P.K. Dearden, S.J. Sowerby (2003). Physical law not natural selection as the major determinant of biological complexity in the subcellular realm: new support for the pre-Darwinian conception of evolution by natural law. Biosystems 71(3):297-303

P.K. Dearden, M. Grbic´, C. Donly (2003). Vasa expression and Germ Cell Specification in the Spider mite Tetranychus urticae. Genes, Development and Evolution 212: 599-603

P.K. Dearden, C Donly and M Grbic´(2002). Expression of pair-rule gene homologues in a chelicerate: early patterning of the Two-Spotted Spider Mite Tetranychus urticae. Development 129(23):5461-5472

C. Chang, P.K. Dearden and M. Akam (2002). Expression of the germ determinant vasa in the grasshopper, Schistocerca gregaria. Developmental Biology 252(1):100-118

P.K. Dearden, M. Akam (2001). Early embryo patterning in the Grasshopper, Schistocerca gregaria; wingless, dpp and caudal expression. Development 128(18):3435-3444

N. Lawrence, P.K. Dearden, D. Hartley, J. Roose, H. Clevers, and A. Martinez Arias (2000). A Groucho protein that lacks the WD40 repeats modulates Wingless signalling in Drosophila and reveals dominant repressor properties of dTCF. International Journal of Developmental Biology 44(7):749-756

P.K. Dearden, M. Grbic´, F. Falciani, M. E. Akam (2000). Maternal and Early Zygotic expression of the Hox3/zen gene of the Grasshopper Schistocerca gregaria. Evolution and Development 2(5):261-270

P.K. Dearden, M. E. Akam (2000). A role for Fringe in segment morphogenesis but not segment formation in the grasshopper, Schistocerca gregaria. Development, Genes and Evolution 210(7):329-336

P.K. Dearden, M.E. Akam (2000). Segmentation in silico. Nature 406(6792):131-132

P.K. Dearden, M.E. Akam (1999). Developmental evolution: Axial patterning in insects.
Current Biology 26(9):16 R591-4