Thursday, February 24, 2011

Images of Science

The 11th Wellcome Image Awards were announced on 23 February 2011, recognising the creators of the most informative, striking and technically excellent images among recent acquisitions to Wellcome Images, as chosen by a panel of judges.
All of the winners can be seen on the awards website. A few of my favourites are presented below.

Cavefish Embryo
Confocal micrograph of a cavefish embryo at around five-days-post-fertilization, viewed from the side (lateral view). The embryo has been stained with an antibody that targets a calcium binding protein (calretinin) shown in green, which highlights different neuronal types and their processes in the nervous system. This staining also reveals taste buds, that in the cavefish are located around the mouth and extend along the body.

The eyes are still present at this stage of development but they will degenerate naturally during the lifetime of the fish as they live in a dark environment where eyes are redundant. Thus, adult cavefish are blind.

Ruby tailed wasp
Photomicrograph of the ruby-tailed wasp. Chrysis ignita is the most commonly observed (of several) species of the ruby-tailed wasp. It is easily recognised by the vibrant iridescent colours on its body. The head and thorax is a metallic green / blue, while the abdomen is a ruby red / bronze colour, which gives it its name. The underside of the abdomen is also concave, which allows the wasp to roll itself into a protective ball if threatened.

Ruby tailed wasps are 'parasitoids' meaning that they eventually kill their hosts. Chrysis ignita parasitizes Mason Bees - the females lay their eggs in the same nest as mason bees, so, when the ruby-tailed wasp larvae hatch, they feed on the mason bee larvae. Ruby tailed wasps do have a sting but it is not functional and most species have no venom.

Cell division and gene expression in plant cells
Fluorescent micrograph showing cell division in an Arabidopsis seedling used to study in vivo gene expression and cell growth analysis, cell by cell from living tissue

Using this technique fluorescent proteins are targeted to the nucleus, so plants can be imaged as they grow, this also allows for simultaneous and automated quantification of gene activity and cell growth in a cell-by-cell basis. As the plant is alive different time points can be captured to track changes in cell size and gene activity in each cell. Information regarding cell growth and gene activity can be extracted from living tissue at different stages.

The red fluorescence is always expressed (acts as a reference), other promoters of interest are fused to different fluorescent proteins and co localized to the nucleus. In this case the green fluorescent protein (GFP) is regulated by a gene of interest (and is therefore only expressed when that gene is active and is therefore variable among cells). A third fluorescent protein is attached to plasma membrane to visualise the segmentation of cells as they grow.

Small red cells that don't have the gene active and do not express GFP are precursors of stomata. Cells that are yellow have both the red and green expressed.

Ergot fungus infection in wheat
Fluorescent micrograph showing wheat stigmas infected with the ergot fugus (Claviceps), which causes ergotism in humans.


  © Communicate Science; Blogger template 'Isolation' by 2012

Back to TOP