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Full-Text Articles in Cell and Developmental Biology

Arctic Mustard Flower Color Polymorphism Controlled By Petal-Specific Downregulation At The Threshold Of The Anthocyanin Biosynthetic Pathway, Cynthia A. Dick, Jason Buenrostro, Timothy Butler, Matthew L. Carlson, Daniel J. Kliebenstein, Justen B. Whittall Apr 2011

Arctic Mustard Flower Color Polymorphism Controlled By Petal-Specific Downregulation At The Threshold Of The Anthocyanin Biosynthetic Pathway, Cynthia A. Dick, Jason Buenrostro, Timothy Butler, Matthew L. Carlson, Daniel J. Kliebenstein, Justen B. Whittall

Biology

Intra- and interspecific variation in flower color is a hallmark of angiosperm diversity. The evolutionary forces underlying the variety of flower colors can be nearly as diverse as the colors themselves. In addition to pollinator preferences, non-pollinator agents of selection can have a major influence on the evolution of flower color polymorphisms, especially when the pigments in question are also expressed in vegetative tissues. In such cases, identifying the target(s) of selection starts with determining the biochemical and molecular basis for the flower color variation and examining any pleiotropic effects manifested in vegetative tissues. Herein, we describe a widespread purple-white …


Bacterial Cell Biology: Managing Magnetosomes, Craig Stephens May 2006

Bacterial Cell Biology: Managing Magnetosomes, Craig Stephens

Biology

Sensing of magnetic fields by living organisms — magnetosensing — is best understood in magnetotactic bacteria. Recently work has provided new insight into the biogenesis of bacterial magnetosomes, and links these organelles to a newly recognized prokaryotic cytoskeletal filament which organizes magnetosomes into a sensory structure capable of aligning cells with the geomagnetic field.


Transcriptional Profiling Of Caulobacter Crescentus During Growth On Complex And Minimal Media, Craig Stephens, Alison K. Hottes, Maliwan Meewan, Desiree Yang, Naomi Arana, Pedro Romero, Harley H. Mcadams. Mar 2004

Transcriptional Profiling Of Caulobacter Crescentus During Growth On Complex And Minimal Media, Craig Stephens, Alison K. Hottes, Maliwan Meewan, Desiree Yang, Naomi Arana, Pedro Romero, Harley H. Mcadams.

Biology

Microarray analysis was used to examine gene expression in the freshwater oligotrophic bacterium Caulobacter crescentus during growth on three standard laboratory media, including peptone-yeast extract medium (PYE) and minimal salts medium with glucose or xylose as the carbon source. Nearly 400 genes (approximately 10% of the genome) varied significantly in expression between at least two of these media. The differentially expressed genes included many encoding transport systems, most notably diverse TonB-dependent outer membrane channels of unknown substrate specificity. Amino acid degradation pathways constituted the largest class of genes induced in PYE. In contrast, many of the genes upregulated in minimal …


Identification Of The Flii And Flij Components Of The Caulobacter Flagellar Type Iii Protein Secretion System, Craig Stephens, Chris Mohr, Charles Boyd, Janine Maddock, James Gober, Lucy Shapiro Sep 1997

Identification Of The Flii And Flij Components Of The Caulobacter Flagellar Type Iii Protein Secretion System, Craig Stephens, Chris Mohr, Charles Boyd, Janine Maddock, James Gober, Lucy Shapiro

Biology

Caulobacter crescentus is motile by virtue of a polar flagellum assembled during the predivisional stage of the cell cycle. Three mutant strains in which flagellar assembly was blocked at an early stage were isolated. The mutations in these strains mapped to an operon of two genes, fliI and fliJ, both of which are necessary for motility. fliI encodes a 50-kDa polypeptide whose sequence is closely related to that of the Salmonella typhimurium FliI protein, an ATPase thought to energize the export of flagellar subunits across the cytoplasmic membrane through a type III protein secretion system. fliJ encodes a 16-kDa hydrophilic …