Meiotic proteins Bqt1 and Bqt2 tether telomeres to promote the bouquet arrangement of chromosomes in fission yeast

In many organisms, meiotic chromosomes are bundled at their telomeres to form a bouquet arrangement. The bouquet formation plays an important role in homologous chromosome pairing and therefore progression of meiosis. As meiotic telomere clustering occurs in response to mating pheromone signaling in fission yeast, we looked for factors essential for bouquet formation among genes induced under mating pheromone signaling. This genome-wide search identified two novel proteins, Bqt1 and Bqt2, that connect telomeres to the spindle-pole body (SPB; the centrosome equivalent in fungi). Neither Bqt1 nor Bqt2 alone functions as a connector, but together the two proteins form a bridge between Rap1 (a telomere protein) and Sad1 (an SPB protein). Significantly, when both Bqt1 and Bqt2 are ectopically expressed in mitotic cells, they also form a bridge between Rap1 and Sad1. Thus, a complex including Bqt1 and Bqt2 is essential for connecting telomeres to the SPB. Keywords: Keywards: Time course, Nitrogen starvation, Mating pheromone, P-factor. Gene expression profile under nitrogen starvation in the absence or presence of mating pheromone in fission yeast. Type of experiment: Comparing between vegetatively-growing control cells and cells in each experimental condition. Experimental factor: Time course after nitrogen starvation in the presence or absence of P-factor. Quality control steps taken: All experiments were repeated twice in each condition.