Cellulose synthesis in two secondary cell wall processes in a single cell type

Alternatives to the Draize rabbit eye irritation test are currently being investigated. Because of morphological and biochemical differences between the rabbit and the human eye, continuous human cell lines have been proposed for use in ocular toxicology studies. Single cell-type monolayer cultures in culture medium have been used extensively in ocular toxicology. In the present study, an SV40-immortalised human corneal epithelial (HCE) cell line was characterised immunohistochemically, by using 13 different monoclonal antibodies to cytokeratins (CKs), ranging from CK3 to CK20. The results from the monolayer HCE cell cultures were compared with those from the corneal epithelium of human corneal cryostat sections. Previous studies have shown that the morphology of the HCE cell is similar to that of primary cultured human corneal epithelial cells, and that the cells express the cornea-specific CK3. In the study reported here, we show that the cell line also expresses CKs 7, 8, 18 and 19. These CKs are typically expressed by simple epithelial cells, and are not found in the human cornea in vivo. Therefore, the monolayer HCE cell line grown in culture medium does not express the CK pattern that is typical of human corneal epithelium. This should be taken into consideration when using HCE cell cultures in similar single cell-type experiments for ocular toxicology.

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A Workflow in Single Cell-Type Metabolomics: From Data Pre-Processing and Statistical Analysis to Biological Insights

OMICS-Based Approaches in Plant Biotechnology ◽

10.1002/9781119509967.ch6 ◽

2019 ◽

pp. 105-127

Author(s):

Biswapriya B. Misra

Keyword(s):

Statistical Analysis ◽

Single Cell ◽

Cell Type ◽

Single Cell Type

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Species Having C4 Single-Cell-Type Photosynthesis in the Chenopodiaceae Family Evolved a Photosynthetic Phosphoenolpyruvate Carboxylase Like That of Kranz-Type C4 Species

PLANT PHYSIOLOGY ◽

10.1104/pp.106.085829 ◽

2006 ◽

Vol 142 (2) ◽

pp. 673-684 ◽

Cited By ~ 27

Author(s):

María Valeria Lara ◽

Simon D.X. Chuong ◽

Hossein Akhani ◽

Carlos Santiago Andreo ◽

Gerald E. Edwards

Keyword(s):

Single Cell ◽

Phosphoenolpyruvate Carboxylase ◽

Cell Type ◽

C4 Species ◽

Single Cell Type

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A Single-Cell-Type Real-Time PCR Method Based on a Modified Patch-Pipette Cell Harvesting System

Molecular Biotechnology ◽

10.1007/s12033-016-9953-y ◽

2016 ◽

Vol 58 (8-9) ◽

pp. 558-565 ◽

Cited By ~ 3

Author(s):

Yuanlong Song ◽

Miaomiao Zhang ◽

Xiaoqing Tao ◽

Zifen Xu ◽

Liangpin Zhang ◽

...

Keyword(s):

Single Cell ◽

Real Time ◽

Real Time Pcr ◽

Cell Type ◽

Cell Harvesting ◽

Patch Pipette ◽

Pcr Method ◽

Single Cell Type

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Rapid cell expansion and cellulose synthesis regulated by plasmodesmata and sugar: insights from the single-celled cotton fibre

Functional Plant Biology ◽

10.1071/fp06234 ◽

2007 ◽

Vol 34 (1) ◽

pp. 1 ◽

Cited By ~ 66

Author(s):

Yong-Ling Ruan

Keyword(s):

Cell Wall ◽

Cell Biology ◽

Secondary Cell Wall ◽

Higher Plants ◽

Single Cells ◽

Critical Role ◽

Fibre Length ◽

Cotton Fibre ◽

Cellulose Synthesis ◽

Temporary Closure

Higher plants comprise mixtures of some 40 different cell types, and this often complicates the interpretation of data obtained at the tissue level. Studies for a given cell type may provide novel insights into the mechanisms underlying defined cellular and developmental processes. In this regard, the cotton fibre represents an excellent single-cell model to study the control of rapid cell elongation and cellulose synthesis. These single cells, initiated from the ovule epidermis at anthesis, typically elongate to ~3–5 cm in the tetraploid species before they switch to intensive secondary cell wall cellulose synthesis. By maturity, more than 94% of fibre weight is cellulose. To unravel the mechanisms of fibre elongation and cellulose synthesis, two hypotheses have been examined: (a) that sucrose degradation and utilisation mediated by sucrose synthase (Sus) may play roles in fibre development and (b) that symplastic isolation of the fibre cells may be required for their rapid elongation. Reverse genetic and biochemical analyses have revealed the critical role that Sus plays in fibre initiation and early elongation. Late in development, plasma-membrane and cell wall association of Sus protein seems to be involved in rapid cellulose synthesis. Cell biology and gene expression studies showed a temporary closure of fibre plasmodesmata (PD), probably due to the deposition of callose, at the rapid phase of elongation. The duration of the PD closure correlates positively with the final fibre length attained. These data support the view that PD closure may be required for fibres to achieve extended elongation. The branching of PD towards the secondary cell wall stage is postulated to function as a molecule sieve for tight control of macromolecule trafficking into fibres to sustain intensive cellulose synthesis.

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A smoothed EM-algorithm for DNA methylation profiles from sequencing-based methods in cell lines or for a single cell type

Statistical Applications in Genetics and Molecular Biology ◽

10.1515/sagmb-2016-0062 ◽

2017 ◽

Vol 16 (5-6) ◽

Cited By ~ 1

Author(s):

Lajmi Lakhal-Chaieb ◽

Celia M.T. Greenwood ◽

Mohamed Ouhourane ◽

Kaiqiong Zhao ◽

Belkacem Abdous ◽

...

Keyword(s):

Dna Methylation ◽

Em Algorithm ◽

Single Cell ◽

Cell Lines ◽

Methylation Status ◽

Embryonic Stem ◽

Cell Type ◽

Data Set ◽

Cpg Sites ◽

Single Cell Type

AbstractWe consider the assessment of DNA methylation profiles for sequencing-derived data from a single cell type or from cell lines. We derive a kernel smoothed EM-algorithm, capable of analyzing an entire chromosome at once, and to simultaneously correct for experimental errors arising from either the pre-treatment steps or from the sequencing stage and to take into account spatial correlations between DNA methylation profiles at neighbouring CpG sites. The outcomes of our algorithm are then used to (i) call the true methylation status at each CpG site, (ii) provide accurate smoothed estimates of DNA methylation levels, and (iii) detect differentially methylated regions. Simulations show that the proposed methodology outperforms existing analysis methods that either ignore the correlation between DNA methylation profiles at neighbouring CpG sites or do not correct for errors. The use of the proposed inference procedure is illustrated through the analysis of a publicly available data set from a cell line of induced pluripotent H9 human embryonic stem cells and also a data set where methylation measures were obtained for a small genomic region in three different immune cell types separated from whole blood.

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