Cell-type.specific expression of ep!dermal cytokeratm genes during gastrulauon of Xenopus laevis
نویسندگان
چکیده
Analysis of the spatial pattern of expression of embryo-specific epidermal cytokeratin genes in Xenopus laevis shows earliest activity in the animal pole cells of stage-9 blastulae. These genes are transcribed predominantly in the epithelial or outer ectoderm, to a lesser extent in the sensorial or inner ectoderm, and at low levels if at all in other regions of the embryo. In the early gastrnla the entire ectoderm, including preneural and preepidetmal regions, expresses cytokeratin mRNAs; accumulation of these mRNAs in preneural cells is terminated after contact is made with involuting chordamesoderm. On the basis of this and earlier work (Sargent et al. 1986) we suggest that the pattern of expression of cytokeratin genes in frog embryogenesis is based on prelocalized components modulated by the inductive influence of involuting chordamesoderm. The cytokeratin proteins are deposited in the form of filamentous networks in both layers of the epidermis. In the epithelial layer, a much denser mesh of filaments is facing the outside of the embryo. This polarity is established at the onset of the polymerization of these filaments. Thus, intraembryonic and intracellular localization of keratin gene expression and protein deposition is established at the onset of activation of these genes.
منابع مشابه
Expression of hsp90 Alpha and hsp90 Beta during Xenopus laevis Embryonic Development
Background: Members of the eukaryotic Hsp90 family function as important molecular chaperones in the assembly, folding and activation of cellular signaling in development. Two hsp90 genes, hsp90 alpha and hsp90 beta, have been identified in fish and homeothermic vertebrates but not in poikilothermic vertebrates. In the present study, the expression of hsp90 alpha and hsp90 beta genes in Xenopus...
متن کاملIntegrin Linked Kinase (X-ILK) Function during Embryonic Development and within Adult Tissues of Xenopus laevis
Integrin linked kinase (ILK) is a serine/threonine protein kinase implicated in the phosphatidylinositol 3’kinase (PI3’K) pathway. Integrin linked kinase has been investigated in different organisms such as mammalian systems (human, mice, rat), insects (Drosophila) and nematodes (Cenorhabditis elegans), however to date little data regarding ILK research on amphibians has been reported. In...
متن کاملThe S362A mutation block ROMK2 (Kir1.1b) endocytosis in Xenopus laevis oocyte membrane .
Abstract The S362A mutation block ROMK2 (Kir1.1b) endocytosis in Xenopus laevis oocyte membrane . Saeed Hajihashemi1 , 1-Assistant professor, PhD in Physiology, Department of Physiology, School of Medical science, Arak University of Medical Sciences. Introduction: ROMK channel is localized on the apical membrane of the nephron. Recent studies suggest that endocytosis of ROMK chan...
متن کاملThe expression of melanopsin and clock genes in Xenopus laevis melanophores and their modulation by melatonin
Vertebrates have a central clock and also several peripheral clocks. Light responses might result from the integration of light signals by these clocks. The dermal melanophores of Xenopus laevis have a photoreceptor molecule denominated melanopsin (OPN4x). The mechanisms of the circadian clock involve positive and negative feedback. We hypothesize that these dermal melanophores also present per...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2007