Differential expression of fibroblast growth factor receptors in the developing murine choroid plexus.
The choroid plexuses (CPs) are specialised secretory organs situated within the ventricles of the brain involved in the production of cerebrospinal fluid (CSF) and the maintenance of the blood-CSF barrier. Abnormal function of the CPs can lead to hydrocephalus and raised intracranial pressure, pathologies frequently observed in certain craniofacial syndromes caused by single point mutations in fibroblast growth factor receptors (FGFRs). At present, relatively little is known about the embryonic CPs in terms of gene or protein expression, function as the brain develops or on the potential role of FGFRs within this context. Given the limited information available on the regulation of FGFRs during development of the CPs and periventricular tissues, we have carried out a detailed analysis of the localisation of FGFR1, 2, 3 and 4 proteins in these regions of the murine embryo from the time of formation of the CP in the third ventricle at E12.5 throughout the second half of gestation, and examined the expression of different FGFR isoforms at E12.5 by RT-PCR. We show here that FGFR1 and FGFR4 are expressed in murine CPs at E12.5 but not at E15.5 or E18.5, suggesting a role for the signaling pathways transduced by these receptors at early stages of CP development. In contrast, FGFR2 expression is maintained throughout CP development, indicating that this receptor may play a role in the function of immature and mature CP. Also FGFR3 is detected at each developmental stage studied, but surprisingly its expression appears confined to the nuclei of CP cells, suggesting that FGFR3 in the CP does not respond to extracellular FGFs but may act in intracrine fashion.
Reid
Sarah
S
Developmental Biology Unit, Institute of Child Health, UCL, 30, Guilford Street, London WC1N 1EH, UK.
Ferretti
Patrizia
P
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics*; D002831:Choroid Plexus / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D019465:Craniofacial Abnormalities / Q000150:complications; D004475:Ectoderm / Q000166:cytology / Q000378:metabolism; D004805:Ependyma / Q000166:cytology / Q000378:metabolism; D005260:Female; D005333:Fetus; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D006849:Hydrocephalus / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D007150:Immunohistochemistry; D019586:Intracranial Hypertension / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism; D051379:Mice; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D011247:Pregnancy; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D051496:Receptor, Fibroblast Growth Factor, Type 1; D051497:Receptor, Fibroblast Growth Factor, Type 2; D051499:Receptor, Fibroblast Growth Factor, Type 4; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics
D020033:Protein Isoforms; D012333:RNA, Messenger; D017468:Receptors, Fibroblast Growth Factor; D005346:Fibroblast Growth Factors; C496349:Fgfr1 protein, mouse; C496354:Fgfr2 protein, mouse; C496372:Fgfr4 protein, mouse; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D051497:Receptor, Fibroblast Growth Factor, Type 2; D051499:Receptor, Fibroblast Growth Factor, Type 4