Meeting Abstract
Repetitive elements comprise around two-thirds of the human genome. Large tandem repeats such as ribosomal genes (44kb), segmental duplications (<130 kb), and telomeric repeats comprise the short arms of acrocentric chromosomes. Importantly, these sequences are missing from the human reference genome. Establishing their organization and distribution is crucial to fully understand cellular function. To extend these regions, careful approaches are necessary to ensure accurateness of sequence information, orientation, and placement. Using these kinds of approaches, we have successfully extended the sequence content after the last human ribosomal gene (rDNA) repeat on the telomere side by 550 kb. Currently, our group is sequencing two Hydractinia species, organisms that have already shown great promise for the study of regeneration, early developmental processes, and bioluminescence. Since the overall repeat and AT-content of Hydractinia is quite high (47% and 65%, respectively), we intend to apply similar strategies as those used with the human genome sequence to identify important repetitive regions such as centromeres, telomeres, and rDNA in these de novo assemblies. This will not only enable us to offer a more complete assembly than those of any other available model organism but also provide a foundation for better understanding their origin and biological relevance.
