Characterizing the regulation and function of Zip1 in Saccharomyces cerevisiae meiosis

Sun, Dijue (2016) Characterizing the regulation and function of Zip1 in Saccharomyces cerevisiae meiosis. Doctoral thesis (PhD), University of Sussex.

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Meiosis is characterized by one round of DNA replication followed by two successive rounds of cell division, resulting in a halving of the genome. During meiotic prophase I, many events occur to allow faithful chromosome segregation. At the chromosomal level, homologs align and become closely juxtaposed along their entire lengths via a proteinaceous structure called the synaptonemal complex (SC). DNA double-strand breaks are induced during prophase I, resulting in the formation of crossover between homologs, which leads to the correct segregation during meiosis I. A well-characterized protein, termed Zip1, is the major component of the SC. Zip1 is known to involve in several different processes of meiosis. Firstly, Zip1 is involved during non- homologous centromere coupling. Secondly, Zip1 synapse homologs together. Thirdly, Zip1 promotes crossing over during prophase I as well as required for interference. The work described in this thesis has characterized the functions and regulation of several Zip1-phospho mutants during meiosis. In particular, Zip1-T114 was shown to involve partially during non-homologous centromere coupling. Zip1-S144 is a putative consensus site for Cdc5 phosphorylation and was found to have a role in SC disassembly.

Zip1 has also been known to involve in non-exchange chromosome segregation (NECS). The work described here used time lapse imaging to further study the characteristics of NECS. This study has generated another homeologous chromosome in SK1 strain background. This homeologous chromosome diploid contains one chromosome III from Saccharomyces cerevisiae and one chromosome III from Saccharomyces paradoxus. Both species share 85% homology. Using live cell imaging has revealed that the NECS is very dynamic. This dynamic movement distinguishes from exchange chromosome segregation where stable centromere pairing between homologs was observed. Therefore a model has proposed for NECS, whereby non-exchange centromeres constant been associate and dissociate from prophase until anaphase segregation
during meiosis I.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Life Sciences > Biochemistry
Subjects: Q Science > QD Chemistry > QD0241 Organic chemistry > QD0415 Biochemistry
Depositing User: Library Cataloguing
Date Deposited: 02 Jun 2016 10:52
Last Modified: 20 Aug 2021 06:06

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