Tissue Polarity in the Retina

Author(s):  
Marek Mlodzik
Keyword(s):  
2020 ◽  
Author(s):  
Fumiko Matsukawa Usami ◽  
Masaki Arata ◽  
Dongbo Shi ◽  
Sanae Oka ◽  
Yoko Higuchi ◽  
...  

SummaryThe molecular mechanisms by which cilia orientation is coordinated within and between multiciliated cells (MCCs) is not fully understood. By observing the orientation of basal bodies (BB) in MCCs of mouse oviducts, here, we show that Celsr1, a planar cell polarity (PCP) factor involved in tissue polarity regulation, is dispensable for determining BB orientation in individual cells, whereas CAMSAP3, a microtubule minus-end regulator, is critical for this process but not for PCP. MCCs exhibit a characteristic BB orientation and microtubule gradient along the tissue axis, and these intracellular polarities were maintained in the cells lacking Celsr1, although the intercellular coordination of the polarities was partly disrupted. On the other hand, CAMSAP3 regulated the assembly of microtubules interconnecting BBs by localizing at the BBs, and its mutation led to disruption of intracellular coordination of BB orientation, but not affecting PCP factor localization. Thus, both Celsr1 and CAMSAP3 are responsible for BB orientation but in distinct ways; and therefore, their cooperation should be critical for generating functional multiciliated tissues.


Development ◽  
2014 ◽  
Vol 141 (20) ◽  
pp. 3944-3954 ◽  
Author(s):  
Z. L. Hua ◽  
H. Chang ◽  
Y. Wang ◽  
P. M. Smallwood ◽  
J. Nathans
Keyword(s):  

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1883-1893 ◽  
Author(s):  
R.E. Krasnow ◽  
P.N. Adler

The Drosophila frizzled (fz) gene is required for the development of normal tissue polarity in the epidermis. Genetic epistasis experiments argue that fz is at the top of a regulatory hierarchy that controls the subcellular site for prehair initiation within the cells of the pupal wing (Wong and Adler, 1993; J. Cell Biol. 123, 209–221). Genetic mosaic experiments indicate that fz has both cell autonomous and cell non-autonomous functions that are separately mutable (Vinson and Adler, 1987; Nature 329, 549–551). Two species of fz mRNA have been identified, raising the question as to whether the two functions are provided by a single protein or by two separate protein species. We generated transgenic flies that express each of these mRNAs under the control of an hsp70 promoter. Only one of the transgenes (hsfzI) showed any fz activity. At 29 degrees C, the hsfzI transgene provided almost complete rescue of a null fz mutation, indicating that the protein encoded by this cDNA can fulfill both fz functions. Overexpression of the hsfzI transgene resulted in two distinct tissue polarity phenotypes depending on the time of heat shock.


2020 ◽  
Vol 117 (9) ◽  
pp. 4758-4769 ◽  
Author(s):  
Tao Zhou ◽  
Yunzhe Lu ◽  
Chongshen Xu ◽  
Rui Wang ◽  
Liye Zhang ◽  
...  

Tight junctions (TJs) are fundamental features of both epithelium and endothelium and are indispensable for vertebrate organ formation and homeostasis. However, mice lackingOccludin(Ocln) develop relatively normally to term. Here we show thatOclnis essential for mammary gland physiology, as mutant mice fail to produce milk. Surprisingly,Oclnnull mammary glands showed intact TJ function and normal epithelial morphogenesis, cell differentiation, and tissue polarity, suggesting thatOclnis not required for these processes. Using single-cell transcriptomics, we identified milk-producing cells (MPCs) and found they were progressively more prone to endoplasmic reticulum (ER) stress as protein production increased exponentially during late pregnancy and lactation. Importantly,Oclnloss in MPCs resulted in greatly heightened ER stress; this in turn led to increased apoptosis and acute shutdown of protein expression, ultimately leading to lactation failure in the mutant mice. We show that the increased ER stress was caused by a secretory failure of milk proteins inOclnnull cells. Consistent with an essential role in protein secretion, Occludin was seen to reside on secretory vesicles and to be bound to SNARE proteins. Taken together, our results demonstrate thatOclnprotects MPCs from ER stress by facilitating SNARE-dependent protein secretion and raise the possibility that other TJ components may participate in functions similar toOcln.


2019 ◽  
Vol 132 (10) ◽  
pp. jcs223313 ◽  
Author(s):  
D. Bazzoun ◽  
H. A. Adissu ◽  
L. Wang ◽  
A. Urazaev ◽  
I. Tenvooren ◽  
...  

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Gang Wu ◽  
Jiao Ge ◽  
Xupei Huang ◽  
Yimin Hua ◽  
Dezhi Mu

Congenital heart disease (CHD) is a common cardiac disorder in humans. Despite many advances in the understanding of CHD and the identification of many associated genes, the fundamental etiology for the majority of cases remains unclear. The planar cell polarity (PCP) signaling pathway, responsible for tissue polarity inDrosophilaand gastrulation movements and cardiogenesis in vertebrates, has been shown to play multiple roles during cardiac differentiation and development. The disrupted function of PCP signaling is connected to some CHDs. Here, we summarize our current understanding of how PCP factors affect the pathogenesis of CHD.


2000 ◽  
Vol 2 (7) ◽  
pp. E124-E125 ◽  
Author(s):  
Sergei Sokol
Keyword(s):  

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