Expression of Prox1 during mouse cochlear development.
We carried out an analysis of the expression of Prox1, a homeo-domain transcription factor, during mouse inner ear development with particular emphasis on the auditory system. Prox1 is expressed in the otocyst beginning at embryonic day (E)11, in the developing vestibular sensory patches. Expression is down regulated in maturing (myosin VIIA immunoreactive) vestibular hair cells and subsequently in the underlying support cell layer by E16.5. In the auditory sensory epithelium, Prox1 is initially expressed at embryonic day 14.5 in a narrow stripe of cells at the base of the cochlea. This stripe encompasses the full thickness of the sensory epithelium, including developing hair cells and support cells. Over the next several days the stripe of expression extends to the apex, and as the sensory epithelium differentiates Prox1 becomes restricted to a subset of support cells. Double labeling for Prox1 and cell-type-specific markers revealed that the outer hair cells transiently express Prox1. After E18, Prox1 protein is no longer detectable in hair cells, but it continues to be expressed in support cells for the rest of embryogenesis and into the second postnatal week. During this time, Prox1 is not expressed in all support cell types in the organ of Corti, but is restricted to developing Deiters' and pillar cells. The expression is maintained in these cells into the second week of postnatal life, at which time Prox1 is dynamically down regulated. These studies form a baseline from which we can analyze the role of Prox1 in vertebrate sensory development.
Virginia Merrill Bloedel Hearing Research Center and Department of Otolaryngology, University of Washington School of Medicine, Seattle, Washington 98195, USA. oliviab@u.washington.edu
Olivia
O
Bermingham-McDonogh
Elizabeth C
EC
Oesterle
Jennifer S
JS
Stone
Clifford R
CR
Hume
Huy M
HM
Huynh
Toshinori
T
Hayashi
D000818:Animals; D000831:Animals, Newborn; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D003051:Cochlea / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D004622:Embryo, Mammalian; D004848:Epithelium / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D011247:Pregnancy; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D009418:S100 Proteins / Q000378:metabolism; D025521:Tumor Suppressor Proteins; D024723:Ventricular Myosins / Q000235:genetics / Q000378:metabolism; D000098551:Prospero-Related Homeobox 1 Protein
D051792:Basic Helix-Loop-Helix Proteins; D049452:Green Fluorescent Proteins; D018398:Homeodomain Proteins; D018809:Proliferating Cell Nuclear Antigen; D009418:S100 Proteins; D025521:Tumor Suppressor Proteins; D024723:Ventricular Myosins; D000098551:Prospero-Related Homeobox 1 Protein; C500943:Atoh1 protein, mouse; C110294:S100A1 protein; C413374:p27 antigen