| dc.contributor.advisor | Schuh, Melina Dr. | |
| dc.contributor.author | Harasimov, Katarina | |
| dc.date.accessioned | 2022-09-15T10:57:52Z | |
| dc.date.issued | 2022-09-15 | |
| dc.identifier.uri | http://resolver.sub.uni-goettingen.de/purl?ediss-11858/14245 | |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-9443 | |
| dc.language.iso | eng | de |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | |
| dc.subject.ddc | 570 | de |
| dc.title | Actin promotes chromosome aggregation and accurate chromosome segregation in mammalian oocytes | de |
| dc.type | cumulativeThesis | de |
| dc.contributor.referee | Bohnsack, Markus Prof. Dr. | |
| dc.date.examination | 2021-09-22 | de |
| dc.description.abstracteng | Accurate chromosome segregation during meiosis is essential for the formation of a new
life. During meiosis, spindle microtubules bind to the chromosomes’ kinetochores and
arms in order to separate the genetic material. Chromosome movements during cell
division are thus generally thought to be driven by microtubules. Whether actin moves
chromosomes in mammalian mitosis or meiosis is unknown. In this thesis, I studied the
prolonged gap phase between nuclear envelope breakdown and the onset of spindle
microtubule assembly in human and porcine oocytes. Strikingly, I found that actin moves
chromosomes during this early phase of meiosis. In particular, actin transiently clusters
the oocytes’ chromosomes into an aggregate. Chromosome aggregation is driven by
Formin-2- and Spire-nucleated actin cables. The actin cables associate with the chromosomes’
kinetochores and push on chromosome arms while contracting, and thereby drive
chromosome aggregation. I show that chromosome aggregation prevents chromosome
losses during the prolonged gap phase between nuclear envelope breakdown and the onset
of spindle microtubule assembly. In addition, chromosome aggregation limits the
formation of premature incorrect kinetochore-microtubule attachments. Moreover, I
present data that reveal additional unexpected roles for actin and myosins in later stages
of meiosis. Together, my data establish essential roles for actin-dependent chromosome
movements in preventing aneuploidy in mammalian oocytes. | de |
| dc.contributor.coReferee | Lénárt, Peter PhD | |
| dc.contributor.thirdReferee | Urlaub, Henning Prof. Dr. | |
| dc.contributor.thirdReferee | Faesen, Alex Dr. | |
| dc.contributor.thirdReferee | Klopfenstein, Dieter Dr. | |
| dc.subject.eng | mammalian oocytes, actin, myosin | de |
| dc.identifier.urn | urn:nbn:de:gbv:7-ediss-14245-8 | |
| dc.date.embargoed | 2024-09-21 | |
| dc.affiliation.institute | Biologische Fakultät für Biologie und Psychologie | de |
| dc.subject.gokfull | Biologie (PPN619462639) | de |
| dc.description.embargoed | 2024-09-21 | de |
| dc.identifier.ppn | 1816890375 | |
| dc.identifier.orcid | 0000-0003-2703-4342 | de |
| dc.notes.confirmationsent | Confirmation sent 2022-09-15T11:15:01 | de |