Lake Forest College, Biology, Springfield, IL 62711
Telomeres are the genomic structures at the ends of chromosomes that protect cells from losing genetic information during replication. In many multicellular organisms, the telomeres shorten during cell replication, serving as a molecular clock of aging. Telomerase is an enzyme that synthesizes telomeres continually during growth of most microbes. The telomerase complex consists of a protein component called the telomerase reverse transcriptase, or TERT, and an RNA component called the telomerase RNA, or TER. The TER consists of a template region used to synthesize a repeated telomeric sequence, TTAGGG. This repeat is conserved across vertebrates, including humans, and is also found in the filamentous fungi such as Aspergillus nidulans, the model organism used in our studies. In our lab, we have identified the most likely TER sequence but have not yet verified the sequence genetically. Here, we used a kind of Polymerase Chain Reaction (PCR), termed fusion PCR, to synthesize a DNA construct that carries a mutation and will ultimately knock out the putative TER sequence. Upon transformation of Aspergillus nidulans with this construct and integration into the genome via homologous recombination, we anticipate observing a “sick” phenotype of these “TER knockout” cells, most likely as abnormally small colonies. When obtained, these results will allow us to confirm the telomerase RNA sequence in Aspergillus nidulans and give us insights into the molecular clock of aging.
[Abstract (DOCX)]