Sebastian Marquardt's Lab
Only a small proportion of the DNA in higher organisms represents genes. Curiously most of what we know about genomic information is derived from studying this minority (e.g. 3% of the human genome comprises genes). The number of genes does not scale with organismal complexity; it is for example similar in humans and worms. We are interested in elucidating functional contributions of the majority of DNA sequences that do not code for proteins (non-coding DNA). We know far less about non-coding DNA sequences than genes.
Identifying the biological roles of non-coding DNA represents a pressing question in current genomics research. Interestingly, most non-coding sequences are actively transcribed by RNA polymerase II (Pol II) to yield long non-coding RNA (lncRNA). Gene promoters represent a conserved source of lncRNA through divergent non-coding transcription. However, the generated lncRNA molecules are not usually conserved, whereas genome-wide non-coding Pol II transcription is found in wide range of organisms.
Our lab is thus interested in the functional consequences of non-coding transcription independent of the lncRNA molecules. We study how the mechanism of Pol II transcription of non-coding regions affects nearby gene expression through changes in chromatin packaging and modification. Non-coding transcription is sensitive to the cellular environment and responds dynamically. Currently, we are pursuing how this dynamic non-coding transcription may be part of plant environmental sensing mechanisms by studying transcription kinetics in environmental interactions.