Nepravilnosti u mitozi i mejozi – bolesti i evolucija

undergraduate thesis

• Title (english): berrations in Mitosis and Meiosis – Disorders and the Evolution
• Author: Lucija Šimić
• Mentor: Višnja Besendorfer (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2022-09-21, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Tijekom razvoja eukariota pojavili su se procesi mitoze i mejoze, a o njihovoj važnosti
govori i činjenica da su rašireni među svim živućim eukariotima. Za razvoj mitoze bila je ključna
pojava mitohondrija, a homolozi svih važnijih mitotskih molekula pronađeni su prokariotima.
Evolucija mejoze je kontroverznija te se može podijeliti u dvije teorije: mejoza se razvila iz
bakterijske transformacije i mejoza se razvila iz mitoze. Kod svih eukariotskih organizama su
pronađeni mejotski geni, što pokazuje da, prema današnjim dokazima, nije postojao period u
eukariotskoj evoluciji gdje mejoza nije bila prisutna. Bolesti u mitozi i mejozi su uzrokovane
nepravilnim razdvajanjem sestrinskih kromatida ili homolognih kromosoma, što rezultira
aneuploidnim brojem kromosoma. Mitotske aneuploidije kod ljudi mogu dovesti do nastanka
raka, dok mejotske aneuploidije najčešće rezultiraju trisomijama i monosomijama. Aneuploidije
spolnih kromosoma se bolje podnose u odnosu na autosomalne zbog inaktivacije svih kopija
kromosoma X osim jedne ili malog broja gena prisutnih na kromosomu Y.

Abstract (english)

The processes of mitosis and meiosis appeared during the development of eukaryotes,
and the fact that they are spread among all living eukaryotes speaks of their importance. The
appearance of mitochondria was crucial for the development of mitosis, and homologues of all
important mitotic molecules have been found in prokaryotes. The evolution of meiosis is more
controversial and can be divided into two theories: meiosis evolved from bacterial transformation
and meiosis evolved from mitosis. Meiotic genes have been found in all eukaryotic organisms,
which shows that, according to today's evidence, there was no period in eukaryotic evolution
where meiosis was not present. Disorders in mitosis and meiosis are caused by nondisjunction of
sister chromatids or homologous chromosomes, resulting in an aneuploid number of
chromosomes. Mitotic aneuploidies in humans can lead to cancer, while meiotic aneuploidies
most often result in trisomies and monosomies. Sex chromosome aneuploidies are more tolerable
than autosomal ones due to the inactivation of all copies of the X chromosome except for one or a
small number of genes present on the Y chromosome.

• Keywords: mitoza; mejoza; evolucija; aneuploidija; nepravilno razdvajanje kromosoma
• Keywords (english): mitosis; meiosis; evolution; aneuploidy; chromosome nondisjunction
• Language: croatian
• URN:NBN: urn:nbn:hr:217:557809
• 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: 2022-10-06 12:37:56