Stress Granules
Microphotography by ~lady-alessandra

Stress granules are ribonucleoprotein structures that form in cell cytoplasm under stress conditions.

Their function is still not completely clear, but it is known that stress response due to sublethal harsh conditions prevents cell death caused by otherwise lethal stimuli applied later. Whether the formation of granules is essential for this protective effect is not known.

Here we treated U2OS [osteosarcoma] cells with arsenite and stopped the noxious stimulus at different times.

  • Then we immunostained with antibodies against eIF2alpha, which is known to accumulate in stress granules (green),
  • red fluorescent phalloidin (which binds to actin filaments, allowing to see cell shape)
  • and DAPI (a blue stain which binds DNA).

You can see how eIF2alpha is widespread in the cytoplasm under basal conditions, being recruited to stress granules when the cell is under harsh conditions.

Bipolar Cells of the Mouse Retina

In the retina, bipolar cells are situated between photoreceptors and ganglion cells. They act, directly or indirectly (via amacrine cells), to transmit signals from the photoreceptors to the ganglion cells. Each bipolar cell can synapse with either rods or cones, but not both (hence the name “bipolar”). There are ten distinct types of cone bipolar cells in the mammalian retina, and only one type of rod bipolar cell (stained red in the image above).

Bipolar cells can be further classified as “ON” or “OFF” based on how they react to changes in the release of glutamate by photoreceptors. When light hits a photoreceptor cell, the photoreceptor hyperpolarizes and releases less glutamate. ON bipolar cells (stained blue in the image above) will respond to this change by depolarizing and OFF bipolar cells will respond by hyperpolarizing.

Image by Luca Della Santina, courtesy of Rachel Wong, University of Washington.

Drosophila melanogaster (stage 16 embryo)
Marine Biological Laboratory, Woods Hole, via ZEISS Microscopy on Flickr.

Ventral view of stage 16 Drosophila melanogaster embryo

Immunostained for Tropomyosin (green; muscle), Pax 3/7 (blue; segmentally repeated nuclei in CNS and ectoderm), and anti-HRP (red; cell bodies and axons of the nervous system). All nuclei shown in gray (DAPI). Imaged with ZEISS LSM 700.

Cross section of the retina from a 5-day-old zebrafish expressing fluorescent protein and immunostained for major retinal cell types. Can you identify the retinal cell types?

Image by Philip Williams, courtesy of Rachel Wong, University of Washington.

Publication date: September 2014
Source:Leukemia Research, Volume 38, Issue 9
Author(s): Ashleigh Allen , Kamraan Gill , Daniela Hoehn , Maria Sulis , Govind Bhagat , Bachir Alobeid
C-myc protein expression has been studied in mature B-cell lymphomas and overexpression has been associated with poor prognosis. We sought to determine the prognostic significance of c-myc protein expression in B-ALL. We found ≥20% c-myc expression to predict risk of persistent disease in all age groups (odds ratio 7.487, p=0.013). There was no statistically significant association between c-myc expression and risk of relapse or death in our study. Routine c-myc immunostaining may help identify higher risk patients and guide management of B-ALL. Additional studies are needed to further determine the molecular mechanisms and role of c-myc expression in B-ALL.

via ScienceDirect Publication: Leukemia Research

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