Položaj kromosoma 1 i 9, obilježenih pomoću tehnologije CRISPR/Cas9, u odnosu na jezgrinu ovojnicu i centrosome

Abstract

Human chromosomes occupy specific territories in the cell nucleus. Chromosomes that are localized at the periphery of the cell nucleus at the onset of mitosis show increased missegregation rates, in compromised mitosis conditions, than the chromosomes that are localized centrally. I specifically labeled subtelomeric region of chromosome 1 and pericentromeric region of chromosome 9 using technology CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9). I determined their position in the cell nucleus, during early prometaphase, with respect to the nuclear envelope and centrosomes. Chromosome 1 is localized at the periphery, whereas chromosome 9 is equally distributed in the cell nucleus during early prometaphase. Furthermore, chromosome 1 and chromosome 9 are both equally polar (closing the angle of >90º with the spindle pole) during early prometaphase. Also, there is no difference in the distance between chromosome 1 and chromosome 9 from the centrosome in early prometaphase and the average distance of the centrosome to the former nuclear envelope in early prometaphase is 2.79 μm. The position of centrosomes during early prometaphase is important from the point of mitotic fidelity. The results of this thesis further support future research of specific chromosome position during early prometaphase.Kromosomi ljudskih stanica zauzimaju specifične teritorije u jezgri. Kromosomi koji se nalaze na periferiji jezgre prije početka mitoze skloniji su pogrešnoj podjeli, u uvjetima narušene mitoze, u odnosu na kromosome koji su pozicionirani centralno. Specifično sam obilježila subtelomernu regiju kromosoma 1 i pericentromernu regiju kromosoma 9 upotrebom tehnologije CRISPR/Cas9 (engl. clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9). Odredila sam položaj navedenih kromosoma u jezgri, tijekom rane prometafaze, u odnosu na jezgrinu ovojnicu i centrosome. Kromosom 1 zauzima periferni položaj, dok je kromosom 9 podjednako distribuiran u svim dijelovima jezgre tijekom rane prometafaze. Nadalje, kromosom 1 i kromosom 9 su podjednako polarni (zatvaraju kut >90º s polom diobenog vretena) tijekom rane prometafaze. Također, ne postoji razlika u udaljenosti kromosoma 1 i kromosoma 9 od centrosoma u ranoj prometafazi te prosječna udaljenost centrosoma od nekadašnje jezgrine ovojnice tijekom rane prometafaze iznosi 2,79 μm. Pozicija centrosoma tijekom rane prometafaze važna je za pravilnu diobu. Rezultati proizašli iz ovoga rada podupiru buduća istraživanja položaja specifičnih kromosoma tijekom rane prometafaze