Birnbaum, K., Shasha, D. E., Wang, J. Y., Jung, J. W., Lambert, G. M., Galbraith, D. W., & Benfey, P. N. (2003). A Gene Expression Map of the Arabidopsis Root. Science, 302(5652), 1956-1960.
PMID: 14671301;Abstract:
A global map of gene expression within an organ can identify genes with coordinated expression in localized domains, thereby relating gene activity to cell fate and tissue specialization. Here, we present localization of expression of more than 22,000 genes in the Arabidopsis root. Gene expression was mapped to 15 different zones of the root that correspond to cell types and tissues at progressive developmental stages. Patterns of gene expression traverse traditional anatomical boundaries and show cassettes of hormonal response. Chromosomal clustering defined some coregulated genes. This expression map correlates groups of genes to specific cell fates and should serve to guide reverse genetics.
Naivar, M., & Galbraith, D. W. (2015). Data acquisition and processing in flow cytometry.. Current Protocols in Cytometry, 71, 10.19.1-10.19.12.. doi:10.1002/0471142956.cy1019s71
Galbraith, D., & Galbraith, D. W. (2009). Simultaneous flow cytometric quantification of plant nuclear DNA contents over the full range of described angiosperm 2C values. Cytometry. Part A : the journal of the International Society for Analytical Cytology, 75(8).
Flow cytometry provides a rapid, accurate, and simple means to determine nuclear DNA contents (C-value) within plant homogenates. This parameter is extremely useful in a number of applications in basic and applied plant biology; for example, it provides an important starting point for projects involving whole genome sequencing, it facilitates characterization of plant species within natural and agricultural settings, it allows facile identification of engineered plants that are euploid or that represent desired ploidy classes, it points toward studies concerning the role of C-value in plant growth and development and in response to the environment and in terms of evolutionary fitness, and, in uncovering new and unexpected phenomena (for example endoreduplication), it uncovers new avenues of scientific enquiry. Despite the ease of the method, C-values have been determined for only around 2% of the described angiosperm (flowering plant) species. Within this small subset, one of the most remarkable observations is the range of 2C values, which spans at least two orders of magnitude. In determining C-values for new species, technical issues are encountered which relate both to requirement for a method that can provide accurate measurements across this extended dynamic range, and that can accommodate the large amounts of debris which accompanies flow measurements of plant homogenates. In this study, the use of the Accuri C6 flow cytometer for the analysis of plant C-values is described. This work indicates that the unusually large dynamic range of the C6, a design feature, coupled to the linearity of fluorescence emission conferred by staining of nuclei using propidium iodide, allows simultaneous analysis of species whose C-values span that of almost the entire described angiosperms.
Galbraith, D. W. (2014). Challenges and Solutions in Cytometric Measurements of Non-Mammalian Species. Cytometry, 85A(10), 831-832.
Cytometric instruments and the associated measurement methodologies were generally developed to enable examination of the properties of mammalian cells, tissues, and organs, with a major concern being that of human health. This general statement is particularly applicable to flow cytometric measurements, which were originally used for the study of blood cells, and analysis of these cells and their subsets remains a major fraction of the activities in flow cytometry and cell sorting. Although this statement is less applicable to image cytometry, including microscopy in its various forms, both flow and image cytometry encounter technical difficulties when they are applied outside the field of mammalian biology. Part of this relates to structural issues: cells of non-mammalian origin are often of sizes very different to those of mammals, and may come in the form of tissues and organs that are difficult to convert into single cell suspensions. Cell suspensions obtained from natural non-mammalian ecosystems may also comprise mixtures of cells of very different sizes. Part of this also relates to the functional activities of non-mammalian cells in producing secondary products, or other polymeric components that can interfere with cytometric measurements. This special section describes four recent articles that demonstrate ways in which cytometric methodologies can be improved to ameliorate systematic errors in measurement that are a consequence of the unconventional properties of the cells being studied.
Vasic, B., Ravanmehr, V., & Galbraith, D. (2011). Analysis and synthesis of boolean cell-cycle gene regulatory networks. Proc. 2011 Information Theory and Applications Workshop.
