Úloha transkripčních faktorů při vývoji oka myši

Vidění /zrak je složitý proces, který začíná přenosem a lomem světla přes vysoce specializovanou průhlednou tkáň nazývanou rohovka. Rohovka slouží jako ochranná bariéra a přispívá k zaostřovací schopnosti oka. Vývoj savčí rohovky sestává z několika fází, zahrnující tvorbu rohovkového epitelu (CE), rohovkového stromatu a endotelu (CEn) během embryogeneze, následované postnatální stratifikací epitelu a pravidelnou obnovou odlupovaných povrchových buněk epitelu. Transkripční faktor Paired box protein (Pax) 6 je evolučně konzervovaný transkripční factor, důležitý pro správný vývoj oka. Pro další porozumění úloze Pax6 při vývoji rohovky jsme využili systém Cre-loxP k selektivní inaktivaci Pax6 ve dvou tkáních oka, konkrétně postnatálním CE a tkání "epitelu očního povrchu" (OSE) (rohovka, limbus a spojivka). Vytvořili jsme novou transgenní myší linii s postnatálně specifickou expresí Cre-rekombinázy v CE, Aldh3-Cre. Inaktivace Pax6 v postnatálním CE pomocí Aldh3-Cre vedla k abnormálně tenké rohovce s defekty v buněčné adhezi. Tím jsme přímo prokázali, že Pax6 hraje klíčovou roli v postnatálním vývoji rohovky. Poté jsme selektivně inaktivovali Pax6 v OSE pomocí další specifické myší linie K14- Cre. U těchto myší docházelo ke "konjunktivalizaci" CE a epitelu limbu (přeměně tkáně CE a limbu v tkáň...Vision is a complex process that begins with the transmission and refraction of light through a highly specialised transparent tissue called the cornea. The cornea acts as a protective barrier and contributes to the focusing power of the eye. The development of mammalian cornea is a multiphase process involving the formation of the corneal epithelium (CE), stroma and endothelium (CEn) during embryogenesis, followed by the postnatal stratification of epithelium and constant renewal of desquamated outermost cells. Paired box protein (Pax) 6 is an evolutionarily conserved transcription factor important for the proper development of the eye. To provide further insights into the role of Pax6 in corneal development, we took the advantage of Cre-loxP system for selectively inactivating Pax6 in two ocular domains, specifically, the postnatal CE and the ocular surface epithelium (OSE) (cornea, limbus, and conjunctiva). We generated a novel postnatal CE-specific Cre-expressing transgenic mouse line, Aldh3-Cre. Inactivation of Pax6 in the postnatal CE using Aldh3-Cre resulted in the abnormal thin cornea with defective cell-cell adhesion, thus providing direct evidence for the function of Pax6 in postnatal corneal development. Subsequently, the OSE-specific depletion of Pax6 using K14-Cre, resulted in the...Katedra buněčné biologieDepartment of Cell BiologyPřírodovědecká fakultaFaculty of Scienc

The role of transcription factors in mouse eye development

Vision is a complex process that begins with the transmission and refraction of light through a highly specialised transparent tissue called the cornea. The cornea acts as a protective barrier and contributes to the focusing power of the eye. The development of mammalian cornea is a multiphase process involving the formation of the corneal epithelium (CE), stroma and endothelium (CEn) during embryogenesis, followed by the postnatal stratification of epithelium and constant renewal of desquamated outermost cells. Paired box protein (Pax) 6 is an evolutionarily conserved transcription factor important for the proper development of the eye. To provide further insights into the role of Pax6 in corneal development, we took the advantage of Cre-loxP system for selectively inactivating Pax6 in two ocular domains, specifically, the postnatal CE and the ocular surface epithelium (OSE) (cornea, limbus, and conjunctiva). We generated a novel postnatal CE-specific Cre-expressing transgenic mouse line, Aldh3-Cre. Inactivation of Pax6 in the postnatal CE using Aldh3-Cre resulted in the abnormal thin cornea with defective cell-cell adhesion, thus providing direct evidence for the function of Pax6 in postnatal corneal development. Subsequently, the OSE-specific depletion of Pax6 using K14-Cre, resulted in the..

Chromatin Remodeling Enzyme Snf2h Is Essential for Retinal Cell Proliferation and Photoreceptor Maintenance

Chromatin remodeling complexes are required for many distinct nuclear processes such as transcription, DNA replication, and DNA repair. However, the contribution of these complexes to the development of complex tissues within an organism is poorly characterized. Imitation switch (ISWI) proteins are among the most evolutionarily conserved ATP-dependent chromatin remodeling factors and are represented by yeast Isw1/Isw2, and their vertebrate counterparts Snf2h (Smarca5) and Snf2l (Smarca1). In this study, we focused on the role of the Snf2h gene during the development of the mammalian retina. We show that Snf2h is expressed in both retinal progenitors and post-mitotic retinal cells. Using Snf2h conditional knockout mice (Snf2h cKO), we found that when Snf2h is deleted, the laminar structure of the adult retina is not retained, the overall thickness of the retina is significantly reduced compared with controls, and the outer nuclear layer (ONL) is completely missing. The depletion of Snf2h did not influence the ability of retinal progenitors to generate all the differentiated retinal cell types. Instead, the Snf2h function is critical for the proliferation of retinal progenitor cells. Cells lacking Snf2h have a defective S-phase, leading to the entire cell division process impairments. Although all retinal cell types appear to be specified in the absence of the Snf2h function, cell-cycle defects and concomitantly increased apoptosis in Snf2h cKO result in abnormal retina lamination, complete destruction of the photoreceptor layer, and consequently, a physiologically non-functional retina