The path to life of the zebrafish
This picture of the department of Histology and Bioimaging of the CRMB shows different stages of Zebrafish embryonic development using a confocal laser microscope. The actin is stained red and in blue the yolk, which feeds the developing embryo. The phases are fist one cell, then two cells, four, and finally the result 48 hours after fertilization.
The New Cajal Era
More than 100 years have passed after the first contributions made by Santiago Ramón y Cajal to the neural network theory. Nowadays neuroscientists take advantage of innovative tools to study neural circuits in order to understand complex behaviours.
This image by David D’Amico, from the group on neurobehavioral phenotyping of mouse models of disease at the CRG, shows the hippocampus of a transgenic mouse expressing yellow fluorescent protein (YFP) in specific subsets of central neurons. This type of tansgenic mice help scientists to understand neural networks in both physiological and pathological conditions.
Little big fly
In this photo taken by Cristina Morera Albert, of the CMRB, a house fly is observed with a scanning electron microscope (SEM). This type of microscope uses electrons and electromagnetic lenses to “illuminate” a sample allowing visualising the sample in 3D at high magnification.
In this case, we observe the compound eyes of the fly and its thorax, which is divided into three segments: prothorax, mesothorax and metathorax. The thorax is covered by hairs called bristles, which are always arranged in the same place and have a sensory function. One can also see the wings, which protrude from the second segment, with their nerves.
Breaking the difraction barrier
In this pseudocolored image by Gemma Perez from the UPF, we can observe the improvement in resolution of Stimulated Emission Depletion (STED) microscopy (right), compared with confocal microscopy (left).
STED is one of the recently developed super-resolution methods that have broken the diffraction limit in light microscopy, and the CRG/UPF Advanced Light Microscopy Unit has one of the only two STED systems currently available in Spain.
The dots in the image show the distribution of PatL1, a component of Processing Bodies (PB), dynamic cytoplasmatic granules that are conserved among eukaryotes. PBs are too small and sometimes are in too close vicinity to be properly rendered by confocal imaging, which has a maximal resolution of 200 nm. In contrast, STED microscopy, capable of resolving distances of <80 nm, can show more details of their sizes and distribution (bar= 1 µm).
SVGmap is a configurable image browser for experimental data, a new tool developed by the biomedical genomics group of the GRIB (UPF-IMIM) at the PRBB. According to the group “it is useful to create browsers for individualized high-quality images which change the color of some regions according to some values”. It has recently been published in Bioinformatics.
You can read more about it at Núria López-Bigas’ laboratory blog: http://bg.upf.edu/blog/
Muscle or mosaic?
This image by Francesc Sànchez Corredera, from Esther Barreiro’s lab on Molecular mechanisms of lung cancer predisposition (IMIM-Hospital del Mar), is a 3m thick sample of a Guinea pig diaphragm muscle, dyed with an Anti-Myosin Type II antibody and amplified 20 times. The protein myosin II is expressed in fast muscle fibres, but not in slow ones. This is why in this image we can see the fast muscle fibres in which myosin II is present dyed in brown, while the slow muscle fibres are negative (not dyed and therefore white).
This way, researchers can count the number of fibres of each type and establish a fibrilar percentage of each muscle.
The image, by Laura Quintana (CRG) shows a mouse embryo with double antibody staining for Neurofilament (blue) and E-cadherin (green) proteins, labelling the nervous system and the internal organs respectively. It was captured using OPT (Optical Projection Tomography), a microscopy technique for 3D imaging of specimens of between 1mm-1cm.
The OPT scanner projects light through the cleared specimen (a specimen made transparent using a clearing solution), taking 400 images as it rotates 360º. Those images are reconstructed using computer software to create a 3D image of the whole specimen. Since it uses diverse UV-filters and white light, multiple labelling can be simultaneously captured, as it shows in the image.