scholarly journals Counter-rotational cell flows drive morphological and cell fate asymmetries in mammalian hair follicles

2018 ◽  
Vol 20 (5) ◽  
pp. 541-552 ◽  
Author(s):  
Maureen Cetera ◽  
Liliya Leybova ◽  
Bradley Joyce ◽  
Danelle Devenport
Keyword(s):  
Cell Fate ◽  
Hair Follicles ◽  
Mammalian Hair

scholarly journals Glutamatergic modulation of synaptic‐like vesicle recycling in mechanosensory lanceolate nerve terminals of mammalian hair follicles

2013 ◽  
Vol 591 (10) ◽  
pp. 2523-2540 ◽  
Author(s):  
Robert W. Banks ◽  
Peter M. B. Cahusac ◽  
Anna Graca ◽  
Nakul Kain ◽  
Fiona Shenton ◽  
...  
Keyword(s):  
Hair Follicles ◽  
Nerve Terminals ◽  
Vesicle Recycling ◽  
Mammalian Hair

A homolog of Drosophila Notch expressed during mammalian development

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 199-205 ◽  
Author(s):  
G. Weinmaster ◽  
V.J. Roberts ◽  
G. Lemke
Keyword(s):  
Cell Fate ◽  
In Situ Hybridisation ◽  
Hair Follicles ◽  
Cdna Clones ◽  
Mammalian Development ◽  
Cell Fate Decisions ◽  
Invertebrate Development ◽  
Epidermal Growth ◽  
Local Cell ◽  
Tooth Buds

Drosophila Notch and the related Caenorhabditis elegans proteins lin-12 and glp-1 function as mediators of local cell-cell interactions required for cell-fate decisions during invertebrate development. To investigate the possibility that similar proteins play determinative roles during mammalian development, we isolated cDNA clones encoding rat Notch. The deduced amino acid sequence of this protein contains 36 epidermal growth factor (EGF)-like repeats, and is remarkably similar in both its extracellular and cytoplasmic domains to the sequence of Xenopus Xotch and Drosophila Notch. In the developing central nervous system, in situ hybridisation analyses revealed that Notch transcripts were dramatically restricted to the ventricular proliferative zones of embryonic neuroepithelia. Notch was also strongly expressed during development of non-neural tissues, such as hair follicles and tooth buds, whose correct differentiation requires epithelial-mesenchymal interactions. These data support the hypothesis that Notch plays an essential role in mammalian development and pattern formation that closely parallels its role in the development of invertebrates.

scholarly journals Dermal EZH2 simultaneously orchestrates dermal differentiation and epidermal proliferation during murine skin development

2020 ◽  
Author(s):  
Venkata Thulabandu ◽  
Timothy Nehila ◽  
James W. Ferguson ◽  
Radhika P. Atit
Keyword(s):  
Cell Fate ◽  
Dermal Fibroblast ◽  
Fibroblast Cell ◽  
Hair Follicles ◽  
Dermal Fibroblasts ◽  
Skin Development ◽  
Polycomb Repressive Complex 2 ◽  
Small Molecule Inhibition ◽  
Proliferation And Differentiation ◽  
Epidermal Proliferation

AbstractSkin development and patterning is dependent on factors that regulate the stepwise differentiation of dermal fibroblasts concomitant with dermal-epidermal reciprocal signaling, two processes that are poorly understood. Here we show that dermal EZH2, the methyltransferase enzyme of the epigenetic Polycomb Repressive Complex 2 (PRC2), is a new coordinator of both these processes. Dermal EZH2 activity is present during dermal fibroblast differentiation and is required for spatially restricting Wnt/β-catenin signaling to reinforce dermal fibroblast cell fate. Later in development, dermal EZH2 regulates the differentiation to reticular dermal fibroblasts and initiation of secondary hair follicles. Embryos lacking dermal Ezh2 have elevated epidermal proliferation and differentiation that can be rescued by small molecule inhibition of retinoic acid (RA) signaling. Together, our study reveals that dermal EZH2 acts as a rheostat to control the levels of Wnt/β-catenin and RA signaling to impact fibroblast differentiation cell autonomously and epidermal keratinocyte development non-cell autonomously, respectively.

scholarly journals Identification of Astrotactin2 as a Genetic Modifier That Regulates the Global Orientation of Mammalian Hair Follicles

PLoS Genetics ◽  
2015 ◽  
Vol 11 (9) ◽  
pp. e1005532 ◽  
Author(s):  
Hao Chang ◽  
Hugh Cahill ◽  
Philip M. Smallwood ◽  
Yanshu Wang ◽  
Jeremy Nathans
Keyword(s):  
Genetic Modifier ◽  
Hair Follicles ◽  
Global Orientation ◽  
Mammalian Hair

scholarly journals Mouse notch: expression in hair follicles correlates with cell fate determination.

1993 ◽  
Vol 121 (3) ◽  
pp. 631-641 ◽  
Author(s):  
R Kopan ◽  
H Weintraub
Keyword(s):  
Hair Follicle ◽  
Cell Fate ◽  
Dermal Papilla ◽  
Cell Types ◽  
Cell Interaction ◽  
Hair Follicles ◽  
Skin Development ◽  
High Level ◽  
Cell Cell

Many vertebrate tissues, including skin, are known to develop as a consequence of epithelial-mesenchymal interactions. Much less is known about the role of cell-cell interaction within the epithelial or the mesenchymal compartments in morphogenesis. To investigate cell-cell interactions during skin development, and the potential role of the Notch homolog in this process, we cloned the mouse homolog of Notch (mNotch) and studied its expression pattern, starting as early as mesoderm formation. The novel application of double-labeled in situ hybridization in vertebrates allowed high resolution analysis to follow the fate of mNotch expressing cells directly. In comparison with the distribution of Id mRNA, analysis confirmed that in the hair follicle high levels of mNotch are expressed exclusively in the epithelial compartment. Hair follicle matrix cells start expressing mNotch as different cell types become distinguishable in the developing follicle. mNotch mRNA expression persists throughout the growth phase of the follicle and maintains the same expression profile in the second hair cycle. The cells in the follicle that undergo a phase of high level mNotch expression are in transition from mitotic precursors to several discreet, differentiating cell types. Our observations point out that both in time (during development) and in space (by being removed one cell layer from the dermal papilla) mNotch expression is clearly separated from the inductive interactions. This is a novel finding and suggests that mNotch is important for follicular differentiation and possibly cell fate selection within the follicle.

Visualization of Internal Skin Structures with the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 46-47
Author(s):  
Emil Bernstein
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Great Depth ◽  
Hair Follicles ◽  
Depth Of Field ◽  
Pig Skin ◽  
Realistic Picture ◽  
Main Components ◽  
Scanning Electron

An interesting method for examining structures in g. pig skin has been developed. By modifying an existing technique for splitting skin into its two main components—epidermis and dermis—we can in effect create new surfaces which can be examined with the scanning electron microscope (SEM). Although this method is not offered as a complete substitute for sectioning, it provides the investigator with a means for examining certain structures such as hair follicles and glands intact. The great depth of field of the SEM complements the technique so that a very “realistic” picture of the organ is obtained.

Centrosome Aurora A gradient ensures single polarity axis in C. elegans embryos

2020 ◽  
Vol 48 (3) ◽  
pp. 1243-1253 ◽  
Author(s):  
Sukriti Kapoor ◽  
Sachin Kotak
Keyword(s):  
Symmetry Breaking ◽  
Cell Fate ◽  
Cell Cortex ◽  
Axis Formation ◽  
Aurora A Kinase ◽  
Aurora A ◽  
C Elegans ◽  
Cell Embryo ◽  
Polarity Establishment

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.

Centromere assembly and non-random sister chromatid segregation in stem cells

2020 ◽  
Vol 64 (2) ◽  
pp. 223-232 ◽  
Author(s):  
Ben L. Carty ◽  
Elaine M. Dunleavy
Keyword(s):  
Stem Cells ◽  
Cell Division ◽  
Cell Fate ◽  
Sister Chromatid ◽  
Asymmetric Cell Division ◽  
Protein A ◽  
Germline Stem Cells ◽  
Sister Chromatids ◽  
Centromere Protein A ◽  
Oocyte Meiosis

Abstract Asymmetric cell division (ACD) produces daughter cells with separate distinct cell fates and is critical for the development and regulation of multicellular organisms. Epigenetic mechanisms are key players in cell fate determination. Centromeres, epigenetically specified loci defined by the presence of the histone H3-variant, centromere protein A (CENP-A), are essential for chromosome segregation at cell division. ACDs in stem cells and in oocyte meiosis have been proposed to be reliant on centromere integrity for the regulation of the non-random segregation of chromosomes. It has recently been shown that CENP-A is asymmetrically distributed between the centromeres of sister chromatids in male and female Drosophila germline stem cells (GSCs), with more CENP-A on sister chromatids to be segregated to the GSC. This imbalance in centromere strength correlates with the temporal and asymmetric assembly of the mitotic spindle and potentially orientates the cell to allow for biased sister chromatid retention in stem cells. In this essay, we discuss the recent evidence for asymmetric sister centromeres in stem cells. Thereafter, we discuss mechanistic avenues to establish this sister centromere asymmetry and how it ultimately might influence cell fate.

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