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STUDIES ON ARABIDOPSIS PROTEINS REQUIRED FOR THE ESTABLISHMENT AND RELEASE OF SISTER CHROMATID COHESION

BOATENG, KINGSLEY A

Abstract Details

2007, Doctor of Philosophy, Miami University, Chemistry and Biochemistry.
The cohesin complex, composed of SMC1, SMC3, SCC3 and an a-kleisin subunit, is critical for the establishment sister chromatid cohesion during mitosis and meiosis. The Arabidopsis genome contains four a-kleisin genes, SYN1, SYN2, SYN3 and SYN4, one separase gene, AESP, and the plant specific SWI1 gene. The dsy10 mutation, previously identified as a male and female sterile desynaptic mutant, is allelic to the previously characterized SWI1 gene. Using various cytological techniques, we demonstrate here that the establishment of sister chromatid cohesion, pairing, synapsis and recombination are all blocked in dsy10 meiocytes. Finally, alterations in modified histones were observed as early as premeiotic-interphase. These observations suggest that histone modifications at early stages of meiosis are critical for the establishment of cohesion and subsequent meiotic events. AESP was previously reported to be involved in the release of cohesion. Here, we report the further characterization of aesp meiocytes and the effect of the temperature sensitive allele, rsw4. Using various cytological techniques we demonstrate that intact bivalents are present at the end of meiosis. Immunolocalization on AESP-RNAi and rsw4 plants show that the removal of SMC3 is blocked at anaphase I and II, consistent with a role of AESP in the release of cohesion. We also show that AESP may be required for proper spindle structure/function and for cytokinesis. Finally, studies were conducted on SYN2, SYN3 and SYN4 to investigate their potential role in mitosis. Subcellular localization studies on SYN2 and SYN4 suggested they play a role in mitosis; however, syn2-1 and syn4-1 single mutants were normal. In this dissertation we present further characterization of SYN2, SYN3 and SYN4. Phylogenetic analysis shows that SYN2, SYN3, and SYN4 could all represent mitotic cohesins. Consistent with these observations, syn2-1syn4-1 double mutant plants show no detectable developmental/mitotic defects. However, the localization of SYN3 is altered in the nuclei of syn2-1syn4-1 plants; it is found distributed throughout the nucleus in somatic cells of mutant plants in contrast to wild-type plants where SYN3 is preferentially localized in the nucleolus. These results suggest that SYN2 and SYN4 are the primary mitotic cohesins, but that SYN3 may also function in mitosis.
CHRISTOPHER MAKAROFF (Advisor)
226 p.

Recommended Citations

Citations

  • BOATENG, K. A. (2007). STUDIES ON ARABIDOPSIS PROTEINS REQUIRED FOR THE ESTABLISHMENT AND RELEASE OF SISTER CHROMATID COHESION [Doctoral dissertation, Miami University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=miami1185209243

    APA Style (7th edition)

  • BOATENG, KINGSLEY. STUDIES ON ARABIDOPSIS PROTEINS REQUIRED FOR THE ESTABLISHMENT AND RELEASE OF SISTER CHROMATID COHESION. 2007. Miami University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=miami1185209243.

    MLA Style (8th edition)

  • BOATENG, KINGSLEY. "STUDIES ON ARABIDOPSIS PROTEINS REQUIRED FOR THE ESTABLISHMENT AND RELEASE OF SISTER CHROMATID COHESION." Doctoral dissertation, Miami University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=miami1185209243

    Chicago Manual of Style (17th edition)