PhD Scholarship: Role of the Ribosomal DNA Repeats in Chromosome Segregation

Страна: Новая Зеландия;

Дедлайн: 31.12.2010


Специальные условия: Two PhD positions are available in this institution

Адрес: Massey University


Organisms must ensure their chromosomes separate faithfully during division. Failure to do so can result in chromosome nondisjunction and cause disorders, notably Down syndrome in humans. While understanding the systems that bring about faithful chromosome segregation is an area of intense investigation, relatively little is known about whether genomic factors impede segregation. The goal of your project will be to test a novel hypothesis: that the ribosomal DNA repeats (rDNA) are an impediment to accurate chromosome segregation.

The rDNA is a distinctive feature of eukaryote genomes. It forms large tracts of tandemly repeated cistrons (from fifty to many thousands of copies) that occupy the nucleolus and encode the major RNA components of the ribosome. The rDNA is the most heavily-transcribed region of the genome but also has numerous “extra-coding” functions. Several observations suggest that some of these extra-coding functions may make the rDNA refractory to proper chromosome segregation.

In order to test this novel hypothesis, you will use the model genetic organism, Saccharomyces cerevisiae, to investigate the genetic pathways that might result in the rDNA impeding proper chromosome segregation. In particular, you will develop assays to follow meiotic chromosome segregation. You will use mutants in pathways involved in rDNA recombination, rDNA replication timing, cohesin/condensin, and meiotic recombination in conjunction with these assays to determine which pathway(s) are involved in rDNA-mediated chromosome missegregation.