Modeliranje sila odgovornih za pozicioniranje kromosoma u diobenom vretenu

master's thesis

• Title (english): Modeling the forces responsible for positioning chromosomes in the mitotic spindle
• Author: Denis Radolović
• Mentor: Nenad Pavin (mentor)
• Committee member: Nenad Pavin (predsjednik povjerenstva)
• Committee member: Maja Novak (član povjerenstva)
• Committee member: Vedran Đerek (član povjerenstva)
• Committee member: Matko Glunčić (član povjerenstva)
• Committee member: Danko Radić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2024-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Diobeno vreteno biološki je mikrostroj sastavljen od mikrotubula. Njegova uloga u stanici je pravilno, precizno i robusno razdvajanje kromosoma tijekom stanične diobe, zašto mu je potreban mehanizam odredivanja i regulacije vlastite duljine. Interpolarni mikrotubuli sudjeluju u regulaciji duljine posredstvom motornih proteina u antiparalelnom preklopu dvaju mikrotubula i motornih proteina koji minus krajeve mikrotubula povezuju s polovima diobenog vretena. Ovdje uvodimo teorijski opis sila... More motornih proteina na minus krajevima u tri inačice. Numeričkim rješavanjem diferencijalne jednadžbe prvog reda za ravnotežu sila pokazujemo da ovisnost sile motornih proteina na minus krajevima o duljini mikrotubula rezultira stabilnom ravnotežnom duljinom vretena koja ovisi o omjeru brzina koračanja motora na polovima i motora u preklopu. Područje preklopa antiparalelnih mikrotubula, čija je duljina u modelu fiksirana, centrira se u inačici modela sa silama ovisnima o duljini mikrotubula, dok u ostalim inačicama ostaje izmaknuta iz središnjeg položaja. Ovi rezultati sugeriraju da bi na minus krajevima mikrotubula mogao postojati mehanizam regulacije duljine diobenog vretena zasnovan na djelovanju motornih proteina ovisnom o duljini mikrotubula. Less

Abstract (english)

The mitotic spindle is a biological micromachine built from microtubules. Its role in the cell is the regular, precise, and robust separation of chromosomes during cell division, for which it needs a mechanism of measuring and controlling its own length. Interpolar microtubules participate in spindle length control via motor proteins in their antiparallel overlap and motor proteins that connect the spindle poles with microtubule minus ends. Here, we introduce a theoretical description of... More forces by motor proteins at the minus ends in three variations. By numerically solving the first order force balance ODE, we show that the length dependence of the force by minus end motor proteins results in a stable mitotic spindle length which is determined by the ratio of stepping velocities of overlap motors and minus end motors. The antiparallel microtubule overlap region, whose length is fixed in the model, shows centering behavior in the length dependent model variant, while without length dependence it sustains its initial off-centered position. These results suggest a potential motor protein driven, microtubule-length-dependent mechanism of spindle length regulation at microtubule minus ends. Less

• Keywords: diobeno vreteno; mikrotubuli; motorni proteini; minus krajevi; regulacija duljine
• Keywords (english): mitotic spindle; microtubules; motor proteins; minus ends; length regulation
• Language: croatian
• URN:NBN: urn:nbn:hr:217:248511
• Project: Number: 855158; Title: Molekularno podrijetlo aneuploidija u zdravim i bolesnim ljudskim tkivima; Title: Molecular origins of aneuploidies in healthy and diseased human tissues; Acronym: ANEUPLOIDY; Leader: Iva Marija Tolić; Jurisdiction: eu; Funder: Europska unija
• Study programme: Title: The University Integrated Undergraduate and Graduate Programme in Physics; Research Physics; specializations in: Research Physics; Course: Research Physics; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: sveučilišni magistar fizike (sveučilišni magistar fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-09-25
• Created on: 2025-02-01 10:51:51