London, October 10 : A team of researchers from the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, has successfully used a novel microscope to map the behaviour and movements of cells during zebrafish embryonic development, and to create a three-dimensional digital movie of the process.
The researchers claimed that they were the first to complete a developmental blueprint of a vertebrate using the technique called digital scanned laser light-sheet fluorescence microscopy (DSLM).
They said that the technique could also be applied to embryos of other vertebrates such as mice and frogs.
The researchers tracked individual cells making up the zebrafish embryo with the laser microscope, which scans a sheet of light across the sample in many different directions to build up a three-dimensional picture.
They monitored the embryo for over 24 hours as it grew from a single cell to tens of thousands of cells.
Over 400,000 images were created, providing a vast amount of data on cellular positions, movements and divisions.
Writing about the results of their study in the journal Science, team member Jochen Wittbrodt said that the observations were "immediately useful both for research in developmental biology as well as in teaching, considering the many movies we provide to illustrate vertebrate embryogenesis."
"We see many direct applications of our technology: the quantitative study of mutant defects, the analysis of the level of individuality in different embryos of the same species and the establishment of comprehensive databases of organ development and tissue formation, just to name a few," Nature magazine quoted the researcher as saying.
The researchers have revealed that DSLM uses around 5,000-6,000 times less light than in a confocal fluorescence microscope, and thus allows the living embryos to be observed for significantly longer periods of time without damage.
Thus far, scientists have considered mapping the embryonic development of vertebrates to be an unfeasibly enormous task.
"So far, no study has been published providing cellular-level resolution data for an entire living vertebrate embryo," says co-author Philipp Keller.
He revealed that there were only two multi-cellular organisms that had been comprehensively reconstructed in that way-a sea squirt (Ciona intestinalis), and the nematode worm (Caenorhabditis elegans).
"This technology, and these maps, should give vertebrate embryologists the ability to study development with the detail and subtlety that has long been available for worms," said Armand Leroi, an evolutionary developmental biologist from Imperial College London, UK, who researches the development of C.elegans.
"John Sulston got his Nobel not for sequencing the human genome or unravelling molecular signalling pathways, but for sitting down in front of a microscope and drawing pictures of cells. This is the same thing: just more cells - and no drawings," added Leroi.