Otkriće novog tipa pokretnih genetičkih elemenata

undergraduate thesis

• Title (english): Discovery of a new type of mobile genetic elements
• Author: Lucija Papa
• Mentor: Ivana Ivančić Baće (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2014, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Pokretni genetički elementi su definirane sekvence DNA koje imaju sposobnost ugradnje u genom domaćinskih stanica i promjene svoje genetičke lokacije unutar njega. Javljaju se u svim domenama živih organizama, te se smatra da zbog promjena koje unose u genom (npr. inaktivacije gena usred ugradnje ili dopreme novih gena) pokretni genetički elementi djeluju kao jedni od najbitnijih pokretača evolucije. Kaspozoni su novootkriveni tip prokariostkih samo-sintetizirajućih pokretnih genetičkih elemenata. Iako dijele sličosti s većim brojem različitih pokretnih genetičkih elemenata prokariota i eukariota, jedini za pokretanje u genomu domaćina koriste endonukleaze Cas1. Osim gena za endonukleazu Cas1, svi kaspozoni nose i gen za DNA polimerazu polB. Filogenetskim analizama ovih gena istraženi su srodstveni odnosi kaspozona i drugih pokretnih genetičih elemenata. S obzirom na filogeniju kaspozonskih proteina Cas1, pretpostavlja se da su proteini Cas1 sustava CRISPR-Cas, odgovornog za postojanje stečene imunosti kod arheja i bakterija, potekli upravo od kaspozonskih proteina Cas1. Ovo čini kaspozone ključnim dijelom razvoja sustava stečene imunosti kod prokariota.

Abstract (english)

Mobile genetic elements are defined DNA sequences capable of integrating into a host genome and moving from one location in the genome to the other. They are abundant in all three domains of life. Since they can render genes inactive by insertion inside the coding sequence, or bring novel genes to the host cell, mobile genetic elements are considered to be one of the main drivers of evolution. Casposons are recently discovered type of self-synthesizing prokaryotic mobile genetic elements. Although they share a number of traits with different types of prokaryotic and eukaryotic mobile genetic elements, they are the only ones to use Cas1 endonucleases for excision and integration into the host genome. Phylogenetic analysis was used to explore genetic relationships between casposons and other mobile genetic elements. Based on Cas1 protein phylogeny, it is proposed that Cas1 proteins from CRISPR-Cas adaptive immunity system in prokaryotes emerged from casposon Cas1 proteins. This suggests that casposons played a key role in the origin of acquired immunity in archaea and bacteria.

• Keywords: pokretni genetički elementi; kaspozoni
• Keywords (english): mobile genetic elements; casposons
• Language: croatian
• URN:NBN: urn:nbn:hr:217:406852
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-12-11 08:38:51