Roger Jacobs, Ph.D.

Jacobs

Telephone: (905) 525-9140

Office: LSB-429 Ext 27350

Lab: LSB-420 Ext 27991

Email: jacobsr@mcmaster.ca

Interests & Activities

The role of cell surface signaling during development, growth and ageing of the heart in Drosophila, using genetic, morphological and molecular tools.

PRC frontal embryo XC DgDlg

Frontal view of embryonic heart

Cross-section of heart tube, lined by ECM (yellow)

Publications
  • Bogatan S, Cevik D, Demidov V, Vanderploeg J, Panchbhaya A, Vitkin A, Jacobs JR.(2015) Talin Is Required Continuously for Cardiomyocyte Remodeling during Heart Growth in Drosophila. PLoS One. 2015 Jun 25;10(6)pub icon
  • Vanderploeg J, Jacobs JR.(2015) Talin is required to position and expand the luminal domain of the Drosophila heart tube. Dev Biol. 2015 Sep 15;405(2):189-201. pub icon
  • Vanderploeg J, Vazquez Paz LL, MacMullin A, Jacobs JR. (2012) Integrins are required for cardioblast polarisation in Drosophila. BMC Dev Biol. 12:8. pub icon
  • Knox J, Moyer K, Yacoub N, Soldaat C, Komosa M, Vassilieva K, Wilk R, Hu J,Vazquez Paz Lde L, Syed Q, Krause HM, Georgescu M, Jacobs JR.  (2011) Syndecan contributes to heart cell specification and lumen formation during Drosophila cardiogenesis. Dev Biol. 356:279-90. pub icon
  • Moyer KE, Jacobs, JR. (2008) Varicose: a MAGUK required for the maturation and function of Drosophila septate junctions. BMC Dev Biol. 8:99  pub icon
  • MacMullin A and Jacobs, JR. (2006) Slit coordinates cardiac morphogenesis in Drosophila. Dev Biol. 293:154-64. 
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  • Settle, M., Gordon, M.D., Nadella, M., Dankort, D., Muller, W., Jacobs, J.R. (2003) Genetic identification of effectors downstream of Neu (ErbB-2) autophosphorylation sites in a Drosophila model.Oncogene 22:1916-1926. 
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  • Stevens, A. and Jacobs, J.R. (2002) Integrins Regulate Responsiveness to Slit Repellent Signals J. Neurosci. 22: 4448-4455. pub icon
  • Battye, R.A., Stevens, A., Perry, R., and Jacobs, J.R. (2001) Repellent signaling from Slit requires the Leucine Rich Region. J. Neurosci . 21:4290-4298 
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  • Jacobs, J.R. (2000) The Midline Glia of Drosophila: A molecular genetic model for the developmental functions of glia. Prog. Neurobiol. 62:475-508  pub icon
Research

Genetics of cell signaling and development

Our studies are aimed at uncovering the molecules and mechanisms that regulate cell differentiation, and morphogenesis during development. We address these issues in Drosophila, a model organism with state- of-the-art tools to assess gene function and manipulate gene expression in vivo. Our focus is the morphogenesis, growth and aging of the Drosophila heart. The genetic and molecular mechanisms are highly conserved between Drosophila and  mammals. Insights into mechanism are relevant to studies of congenital cardiomyopthies and disorders of cardiac aging, such as cardiac hypertrophy.

Guidance Signaling during heart morphogenesis

We previously demonstrated how Slit, a glycoprotein secreted by the nervous system midline, acts as a repellent signal to guide the extension of developing axons in the CNS. Our current studies reveal that Slit also works to guide cell movement and shape change essential to forming the Drosophila heart. Without Slit,  heart cells cannot align themselves properly to build  the heart tube. Furthermore, Slit is required for the heart to form an inner chamber (lumen) to carry the blood.  Significantly, Slit function in the heart is closely linked to adhesion signals and the extracellular matrix. We are using molecular and genetic techniques to explore how adhesion signals affect the cell shape changes as the heart is formed. The  composition of the extracellular matrix changes with growth and aging. We are examining what signals and physiological circumstances regulate these changes.

Left: sparse fibrils of ECM protein Pericardin (green) overlie the contractile cardiomyocytes (actin-red)

Right: Altered cardiomyocyte adhesion and contraction results in heavier deposition of Pericardin

PRC- larval