A study describes the dynamics of chromatin during organ and tissue regeneration

Researchers in Barcelona, who conducted the analysis with Drosphila melanogaster, discovered a group of genes involved in regeneration and which are kept in different species. The study appears highlighted on the cover of the journal Genome Research.

Researchers have described the genes and regulatory elements of their expression that are required during the process of tissue and organ regeneration. The study, which appears on the cover of the prestigious journal Genome Research, combines the classic genetic analysis with the new study techniques for chromatin through next-generation sequencing, provides with a new perspective in the field of regenerative medicine.

Participants in the study are Elena Vizcaya-Molina (UB) and Cecilia C Klein (CRG-UB), co-first authors of the article, which has been led by Montserrat Corominas (UB). CRG group leader Roderic Guigó (CRG, Pompeu Fabra University) and researchers Florenci Serras (UB) and Rakesh K. Mishra (CCMB, Hyderabad, India) also co-authored the paper.

Regeneration genes

In this article, the authors analysed the transcriptome of imaginal disks in the Drosophila melanogaster’s wing in different regeneration time periods. Through the analysis of massive RNA sequencing, they identified those genes that are differentially expressed during the process. Also, they saw that more than 30 % of these genes are located in gene clusters. Thanks to the comparative analysis conducted on other species (mice and zebra fish), the authors discovered a group of genes involved in regeneration and which are conserved in all those species. “Knowing which genes these organisms –which are able to regenerate- have in common can help us understand what is necessary to activate this process in organisms with more limited regenerative skills, such as humans”, notes Elena Vizcaya-Molina.

“This study shows the growing importance of omics and bioinformatics to understand basic biological processes”, notes the postdoc CRG researcher and UB lecturer, Cecilia Klein. The combination of new sequencing techniques and bioinformatics analysis with the experimental study allows researchers to progress regarding the understanding of gene regulation, in this case, regeneration.

Regulatory elements in regeneration

In this study, researchers also found out for the first time, three kinds of regulatory elements that are related to regeneration: those that increase their activity during regeneration, those that are reused from other development stages or other tissues, and last, a group of unique elements in regeneration. “These regulartory elements are DNA sequences able to lead and shape the gene expression”, says Elena Vizcaya. Also, the authors found that these elements could be activated by some conserved genes among species (fly, mouse and zebra fish). “The ectopic activation of specific regulatory elements of regeneration could be a key tool to boost the organs’ regenerative ability that are not able to regenerate”, concludes th expert Montserrat Corominas.

Flies as model animal in regeneration

Regeneration has been of great interest since ancient times, as seen in Greek mythology legends, for instance. However, the regenerative ability of Drosophila melanogaster, known as fruit fly, was not discovered until the forties, when it was found out by one of the fathers of regenerative medicine. Thomas Morgan saw the fly’s imaginal disks (primordial in adults’ cuticular structures) were able to regenerate after being broken. It’s been some years the fly is regarded as a model to study regeneration.

Reference article: Vizcaya-Molina E, Klein CC, Mishra RK, Serras F, Guigo R, Corominas M. 2018.”Damage responsive elements in Drosophila regeneration”. November 20, 2018. Doi: 10.1101/gr.233098.117