Galbraith, D. W. (2014). Endoreduplicative standards for calibration of flow cytometric C-value measurements.. Cytometry, 85, 368-374.
AbstractIt has been estimated that there are, globally, as many as 400,000 species of the angiosperms (the flowering plants). Of these, a minimal proportion has been characterized at the cytological level. Urgency is required in initiating a systematic and comprehensive census, due to species extinction as a consequence of anthropogenic activities. Fundamental to eukaryotes is the 2C-value, the amount of DNA contained within the nucleus of the unreduced gametes. Flow cytometry provides an ideal method for determining C-values, but the values archived in the Kew Plant C-value Database represent 2% of these species. Complicating the issue is a proliferation of different, and inconsistent standards for C-value measurements utilizing flow cytometry, and variability associated with different instrument platforms and using different staining procedures. In previous work, the use of flow cytometry for analysis of plant nuclear DNA contents for species spanning much of the range of genome sizes found in the angiosperms was described. For this work, an endoreduplicative species (Arabidopsis thaliana L.) was particularly helpful as an internal standard for genome size calibration. Such a standard is compromised if it overlaps in DNA content than that of the species whose genome size is sought. This report describes the use of a second species displaying endoreduplication, Capsicum annuum L., for similar standardization. The results (a) indicate accurate reporting of nuclear DNA contents across a range 0.32-423.68 pg, (b) confirm that endoreduplication increases nuclear DNA contents by complete replication of the genome, and (c) provide a means for quality control of linearity in instrumentation over defined dynamic ranges.
Shoemaker, R. C., Christofferson, S. E., & Galbraith, D. W. (1987). Storage protein accumulation patterns in somatic embryos of cotton (Gossypium hirsutum L.). Plant Cell Reports, 6(1), 12-15.
PMID: 24248439;Abstract:
The storage protein content of somatic embryos of Gossypium hirsutum L. cv. Coker 201 was determined using extinction level, antigen/antibody association detection methods. Mature storage protein was first detected in early globular-stage somatic embryos at a total concentration of 0.36% of the embryo protein mass. Tulip-stage and mature somatic embryos were comprised of 3.0% and 1.3% mature storage protein, respectively. Maximum storage protein synthesis was found to occur during early globular- and early heart-stages. During this period of development, significant levels of protein precursors were found also to accumulate. The pattern of storage protein synthesis, processing and accumulation paralleled the pattern that has been reported for the zygotic system, although somatic embryos accumulate storage protein at much earlier stages and to a lesser degree. The possibility of using complex biochemical pathways to monitor embryogenic systems in vitro is discussed. © 1987 Springer-Verlag.
Macas, J., Lambert, G. M., Dolezel, D., & Galbraith, D. W. (1998). Nuclear expressed sequence tag (NEST) analysis: A novel means to study transcription through amplification of nuclear RNA. Cytometry, 33(4), 460-468.
PMID: 9845441;Abstract:
We describe a novel concept and corresponding methods for the analysis of transcription in higher plant cells. The concept is that an examination of the presence of different polyadenylated transcripts within isolated nuclei reflects the state of gene expression at a given moment more precisely than do conventional techniques using total cellular mRNA. The methods involve isolation of polyadenylated nuclear transcripts from flow-sorted nuclei, reverse transcription, amplification using the polymerase chain reaction, and analysis of the products through gel electrophoresis and sequencing. By using specific primers, we have demonstrated detection of selected gene products in nuclei from transgenic plants. We also employed a technique for analysis of individual transcripts based on the length polymorphisms of restriction fragments derived from their 3' ends. Because the technique does not require a priori knowledge of the analyzed sequences, it is suitable for displaying the complete spectra of RNA transcripts present in nuclei at the moment of their isolation. These fragments can be easily isolated and sequenced and the sequence information used for assignment of putative function of corresponding genes. These techniques have been used to identify leaf-, root- , and cell cycle-specific transcripts. In principle, they should be applicable to the tissues of any eukaryotic species that contain transcriptionally active nuclei.
Bak, S., Tax, F. E., Feldmann, K. A., Galbraith, D. W., & Feyereisen, R. (2001). CYP83B1, a cytochrome P450 at the metabolic branch paint in auxin and indole glucosinolate biosynthesis in Arabidopsis. PLANT CELL, 13(1), 101-111.
Zhang, X., Zhang, L., Dong, F. C., Gao, J. F., Galbraith, D. W., & Song, C. P. (2001). Hydrogen peroxide is involved in abscisic acid-induced stomatal closure in Vicia faba. PLANT PHYSIOLOGY, 126(4), 1438-1448.
