SPbU: a new technique of chromosome microdissection

Researchers from St Petersburg University and Friedrich-Schiller-Universität Jena, headed by Alla Krasikova, Associate Professor at SPbU, have developed a unique technique of chromosome microdissection which allows scientists to obtain and decode even tiny DNA fragments. The research findings have been published in BMC Genomics, a top-rated open access, peer-reviewed journal that considers articles on all aspects of genome-scale analysis, functional genomics, and proteomics.

Currently there is a wide range of cytogenetic and cytological approaches to studying chromosomes – mechanical microdissection among them. Using a fine glass needle mechanical microdissection technique isolates a single chromosome or their regions, which further enables amplification of isolated material and its subsequent molecular cytogenetic analysis or high-throughput sequencing. Chromosome microdissection has been widely used to identify chromosome, chromosomal rearrangements, both evolutionary and clinically significant, architecture of the cell nuclei and etc.

Relatively small physical size of mitotic chromosomes, however, limited the use of the conventional chromosome microdissection for investigation of tiny chromosomal regions. Researchers from SPbU and Friedrich-Schiller-Universität Jena have broken ground on science by developing a workflow for microdissection of giant transcriptionally active chromosomes followed by the preparation of whole-chromosome and locus-specific fluorescent in situ hybridization (FISH)-probes, high-throughput sequencing and mapping the smallest DNA fragments in genomes.   

‘This new technique of chromosome microdissection isolates chromosomal regions as small in size as 1.5–4 mln base pairs, — said Alla Zlotina, a lead author of the article, junior research associate at SPbU. — Now for successful amplification there is enough a tiny fragment of a single copy of chromosome, while previously in microdissection of metaphase chromosomes multiple copies, at least 10-15, of dissected regions, subsequently larger in size, were necessary’.

This big breakthrough came as a result of scientific cooperation between SPbU and Thomas Liehr’s laboratory through inter-university exchange programme. Two leading research centres offered their services and facilities to facilitate the research: Friedrich-Schiller-Universität Jena provided mechanical-microdissection systems, while Research Park at St Petersburg University, equipment for cynogenetic analysis with high accuracy and precision and decoding of genome fragments.

‘The new workflow can be applied for mechanical microdissection of giant transcriptionally active lampbrush chromosomes, — said Alla Krasikova, Associate Professor at SPbU. — The developed technical approach allows to obtain DNA and RNA samples from particular lampbrush chromosome loci, to define precisely the genomic position, extent and sequence content of the dissected regions. Technically unique in its kind and highly efficient, it allows scientists to correlate particular cytological structures and even individual genes with known DNA sequences. Also, it is convenient in performing in-depth analysis of functionally important chromosome regions and mechanisms of how the henetic information is realised’.

Read more at Microdissection of lampbrush chromosomes as an approach for generation of locus-specific FISH-probes and samples for high-throughput sequencing, BMC Genomics, 2016 (DOI: 10.1186/s12864-016-2437-4).