scholarly journals Tamoxifen-inducible gene deletion reveals a distinct cell type associated with trabecular bone, and direct regulation of PTHrP expression and chondrocyte morphology by Ihh in growth region cartilage

2007 ◽  
Vol 308 (1) ◽  
pp. 93-105 ◽  
Author(s):  
Matthew J. Hilton ◽  
Xiaolin Tu ◽  
Fanxin Long
1999 ◽  
Vol 274 (40) ◽  
pp. 28697-28707 ◽  
Author(s):  
Robert M. Tjin Tham Sjin ◽  
Kenneth A. Lord ◽  
Abbas Abdollahi ◽  
Barbara Hoffman ◽  
Dan A. Liebermann

1984 ◽  
Vol 72 (1) ◽  
pp. 101-109
Author(s):  
W.M. Satmary ◽  
T.J. Bradley

The Malpighian tubules of insects are generally composed of more than one cell type. In the hemipteran Rhodnius prolixus, the tubules are divided into two regions, termed the upper and lower tubules, each of which is composed of a distinct cell type. In the dipteran Aedes taeniorhynchus, primary and stellate cells are interspersed throughout the length of the tubules. We report here techniques for the dissociation of the Malpighian tubules of both of these species into single cells. Tubules are removed from the insect and placed for 1 h in insect Ringer containing elastase (Sigma, type III) at 4 mg/ml. This treatment fully removes the basal lamella. Mild agitation by hand produces a suspension of single cells, which remain viable as determined by Trypan Blue exclusion. Isolated cells have been maintained in cell culture for one week. Using light and scanning electron microscopy, upper and lower tubule cells of Rhodnius and primary and stellate cells of Aedes can be distinguished on the basis of size, shape, microvillar length, and the presence or absence of intracellular crystals.


1979 ◽  
Vol 61 (2) ◽  
pp. 213-221 ◽  
Author(s):  
C. M. Timson ◽  
J. M. Polak ◽  
J. Wharton ◽  
M. A. Ghatei ◽  
S. R. Bloom ◽  
...  

Author(s):  
Isabella N. Grabski ◽  
Rafael A. Irizarry

AbstractSingle-cell RNA sequencing (scRNA-seq) quantifies gene expression for individual cells in a sample, which allows distinct cell-type populations to be identified and characterized. An important step in many scRNA-seq analysis pipelines is the annotation of cells into known cell-types. While this can be achieved using experimental techniques, such as fluorescence-activated cell sorting, these approaches are impractical for large numbers of cells. This motivates the development of data-driven cell-type annotation methods. We find limitations with current approaches due to the reliance on known marker genes or from overfitting because of systematic differences between studies or batch effects. Here, we present a statistical approach that leverages public datasets to combine information across thousands of genes, uses a latent variable model to define cell-type-specific barcodes and account for batch effect variation, and probabilistically annotates cell-type identity. The barcoding approach also provides a new way to discover marker genes. Using a range of datasets, including those generated to represent imperfect real-world reference data, we demonstrate that our approach substantially outperforms current reference-based methods, in particular when predicting across studies. Our approach also demonstrates that current approaches based on unsupervised clustering lead to false discoveries related to novel cell-types.


2020 ◽  
Author(s):  
Ali Mohebi ◽  
Karim G. Oweiss

Orienting movements are essential to sensory-guided reward-seeking behaviors. Prefrontal cortex (PFC) is believed to exert top-down control over a range of goal-directed behaviors and is hypothesized to bias sensory-guided movements. However, the nature of PFC involvement in controlling sensory-guided orienting behaviors has remained largely unknown. Here, we trained rats on a delayed two-alternative forced-choice task requiring them to hold an orienting decision in working memory before execution is cued. Medial PFC (mPFC) Inactivation using either Muscimol or optogenetics impaired choice behavior. However, optogenetic impairment depended on the specific trial epoch during which inactivation took place. In particular, we found a lateralized role for mPFC during the presentation of instruction cues but this role became bilateral when inactivation occurred later in the delay period. Electrophysiological recording of multiple single-unit activity further provided evidence that this lateralized selectivity is cell-type specific. Our results suggest a previously unknown role of mPFC in mediating sensory-guided representation of orienting behavior and a potentially distinct cell-type specific role in shaping such representation across time.


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