Investigating the role of the condensin complexes during meiosis in \(Arabidopsis\) \(thaliana\)

Smith, Sarah, Jane (2012). Investigating the role of the condensin complexes during meiosis in \(Arabidopsis\) \(thaliana\). University of Birmingham. Ph.D.

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Abstract

Meiosis is a specialised cell division essential for sexual reproduction. During meiosis the chromosomes are highly organised and correct chromosome architecture is required for meiotic recombination and faithful segregation of chromosomes at anaphase. Condensin is involved in chromosome organisation during meiotic and mitotic cell divisions. Three condensin subunits, including condensin I and II specific subunits AtCAPD2 and AtCAPD3 respectively, have been studied for their role in meiosis using T-DNA insertion plants and an RNAi approach.

The condensin subunit AtSMC4 localised to meiotic chromosomes at metaphase I, where it coated the entire chromosome and remained until telophase. Some evidence of centromere localisation of AtSMC4 was also seen during prophase I and metaphase I. AtSMC4RNAi lines were able to condense their chromosomes into metaphase bivalents which were essentially normal. However at anaphase the chromosomes appeared to lose structural integrity such that a thin curtain of lagging chromatin was seen to trail behind the segregating chromosomes. As in AtSMC4RNAi lines, both condensin I and II specific subunits were also required for chromosome segregation at anaphase I and II. However their roles in this process differed. AtCAPD2RNAi resembled AtSMC4RNAi lines but Atcapd3 plants had a unique anaphase phenotype. It is possible that these two phenotypes represent different manifestations of the same role of maintaining chromosome organisation. Condensin I, but not condensin II was also shown to be required for the organisation of the rDNA and to maintain the structure of the centromeres at metaphase.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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