Dynamic expression of Dab2 in the mouse embryonic central nervous system

Kwok-Kuen Cheung¹^,2 , Samuel C Mok³ , Payam Rezaie⁴^,5 and Wood Yee Chan¹

¹Department of Anatomy, Faculty of Medicine, The Chinese University of Hong Kong, PR China

²Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, PR China

³Department of Gynecologic Oncology University of Texas M.D. Anderson Cancer Center T4.3908, 1515 Holcombe Boulevard Houston, TX 77030, USA

⁴Neuropathology Research Laboratory, Department of Life Sciences, Faculty of Science, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK

⁵Department of Neuroscience, Institute of Psychiatry, King's College London, DeCrespigny Park, London SE5 8AF, UK

author email corresponding author email

BMC Developmental Biology 2008, 8:76doi:10.1186/1471-213X-8-76


Published:	4 August 2008

Abstract

Background

Dab2, one of two mammalian orthologs of Drosophila Disabled, has been shown to be involved in cell positioning and formation of visceral endoderm during mouse embryogenesis, but its role in neuronal development is not yet fully understood. In this report, we have examined the localization of the Dab2 protein in the mouse embryonic central nervous system (CNS) at different developmental stages.

Results

Dab2 protein was transiently expressed in rhombomeres 5 and 6 of the developing hindbrain between E8.5 and E11.5, and in the floor plate of the neural tube from E9.5 to E12.5, following which it was no longer detectable within these regions. Dab2 protein was also identified within circumventricular organs including the choroid plexus, subcommissural organ and pineal gland during their early development. While Dab2 was still strongly expressed in the adult choroid plexus, immunoreactivity within the subcommissural organ and pineal gland was lost after birth. In addition, Dab2 was transiently expressed within a subpopulation of Iba1-positive mononuclear phagocytes (including presumed microglial progenitors) within the neural tube from E10.0 and was lost by E14.5. Dab2 was separately localized to Iba1 positive cells from E9.5 and subsequently to F4/80 positive cells (mature macrophage/myeloid-derived dendritic cells) positioned outside the neural tube from E12.5 onwards, implicating Dab2 expression in early cells of the mononuclear phagocyte lineage. Dab2 did not co-localize with the pan-neuronal marker PGP9.5 at any developmental stage, suggesting that Dab2 positive cells in the developing CNS are unlikely to be differentiating neurons.

Conclusion

This is the first study to demonstrate the dynamic spatiotemporal expression of Dab2 protein within the CNS during development.