http://hdl.handle.net/2440/13307 Fri, 24 May 2013 16:51:45 GMT 2013-05-24T16:51:45Z http://hdl.handle.net/2440/77441 Title: Poor homologous synapsis 1 interacts with chromatin but does not colocalise with ASYnapsis 1 during early meiosis in bread wheat Author: Khoo, Kelvin Han Ping; Able, Amanda Jane; Able, Jason Alan Abstract: Chromosome pairing, synapsis, and DNA recombination are three key processes that occur during early meiosis. A previous study of Poor Homologous Synapsis 1 (PHS1) in maize suggested that PHS1 has a role in coordinating these three processes. Here we report the isolation of wheat (Triticum aestivum) PHS1 (TaPHS1), and its expression profile during and after meiosis. While the TaPHS1 protein has sequence similarity to other plant PHS1/PHS1-like proteins, it also possesses a unique region of oligopeptide repeat units. We show that TaPHS1 interacts with both single- and double-stranded DNA in vitro and provide evidence of the protein region that imparts the DNA-binding ability. Immunolocalisation data from assays conducted using antisera raised against TaPHS1 show that TaPHS1 associates with chromatin during early meiosis, with the signal persisting beyond chromosome synapsis. Furthermore, TaPHS1 does not appear to colocalise with the asynapsis protein (TaASY1) suggesting that these proteins are probably independently coordinated. Significantly, the data from the DNA-binding assays and 3-dimensional immunolocalisation of TaPHS1 during early meiosis indicates that TaPHS1 interacts with DNA, a function not previously observed in either the Arabidopsis or maize PHS1 homologues. As such, these results provide new insight into the function of PHS1 during early meiosis in bread wheat. Description: Extent: 11p. Sat, 31 Dec 2011 13:30:00 GMT http://hdl.handle.net/2440/77441 2011-12-31T13:30:00Z http://hdl.handle.net/2440/75661 Title: Rapid phenotyping for adult-plant resistance to stripe rust in wheat Author: Hickey, Lee T.; Wilkinson, Peter M.; Knight, Cheridan R.; Godwin, Ian Douglas; Kravchuk, Olena; Aitken, Elizabeth; Bansal, U. K.; Bariana, H. S.; DeLacy, Ian H.; Dieters, M. J. Sat, 31 Dec 2011 13:30:00 GMT http://hdl.handle.net/2440/75661 2011-12-31T13:30:00Z http://hdl.handle.net/2440/74742 Title: Feasibility study on the use of multivariate data methods and derivatives to enhance information from barley flour and malt samples analysed using the Rapid Visco Analyser Author: Cozzolino, Daniel; Allder, Katherine Louise; Roumeliotis, Sophia; Eglinton, Jason Konrad Sat, 31 Dec 2011 13:30:00 GMT http://hdl.handle.net/2440/74742 2011-12-31T13:30:00Z http://hdl.handle.net/2440/74373 Title: The isolation and characterisation of the wheat molecular ZIPper I homologue, TaZYP1 Author: Khoo, Kelvin Han Ping; Able, Amanda Jane; Able, Jason Alan Abstract: Background: The synaptonemal complex (SC) is a proteinaceous tripartite structure used to hold homologous chromosomes together during the early stages of meiosis. The yeast ZIP1 and its homologues in other species have previously been characterised as the transverse filament protein of the synaptonemal complex. Proper installation of ZYP1 along chromosomes has been shown to be dependent on the axial element-associated protein, ASY1 in Arabidopsis. Results: Here we report the isolation of the wheat (Triticum aestivum) ZYP1 (TaZYP1) and its expression profile (during and post-meiosis) in wild-type, the ph1b deletion mutant as well as in Taasy1 RNAi knock-down mutants. TaZYP1 has a putative DNA-binding S/TPXX motif in its C-terminal region and we provide evidence that TaZYP1 interacts non-preferentially with both single- and double-stranded DNA in vitro. 3-dimensional dual immunofluorescence localisation assays conducted with an antibody raised against TaZYP1 show that TaZYP1 interacts with chromatin during meiosis but does not co-localise to regions of chromatin where TaASY1 is present. The TaZYP1 signal lengthens into regions of chromatin where TaASY1 has been removed in wild-type but this appears delayed in the ph1b mutant. The localisation profile of TaZYP1 in four Taasy1 knock-down mutants is similar to wild-type but TaZYP1 signal intensity appears weaker and more diffused. Conclusions: In contrast to previous studies performed on plant species where ZYP1 signal is sandwiched by ASY1 signal located on both axial elements of the SC, data from the 3-dimensional dual immunofluorescence localisation assays conducted in this study show that TaZYP1 signal only lengthens into regions of chromatin after TaASY1 signal is being unloaded. However, the observation that TaZYP1 loading appears delayed in both the ph1b and Taasy1 mutants suggests that TaASY1 may still be essential for TaZYP1 to play a role in SC formation during meiosis. These data further suggest that the temporal installation of ZYP1 onto pairing homologous chromosomes in wheat is different to that of other plant species and highlights the need to study this synaptonemal complex protein on a species to species basis. Description: Extent: 13p. Sat, 31 Dec 2011 13:30:00 GMT http://hdl.handle.net/2440/74373 2011-12-31T13:30:00Z