Root elongation in drying soil is generally limited by a combination of mechanical impedance and water stress. Relationships between root elongation rate, water stress (matric potential), and mechanical impedance (penetration resistance) are reviewed, detailing the interactions between these closely related stresses. Root elongation is typically halved in repacked soils with penetrometer resist...

Appropriate embryonic and fetal development significantly impact pregnancy success and, therefore, the efficiency of swine production. The pre-implantation period of porcine pregnancy is characterized by several developmental hallmarks, which are initiated by the dramatic morphological change that occurs as pig blastocysts elongate from spherical to filamentous blastocysts. Deficiencies in blas...

BACKGROUND Sperm length in Drosophilidae varies from a few hundred microns to 6 cm as a result of evolutionary selection. In postcopulatory competition, longer sperm have an advantage in positioning their head closer to the egg. Sperm cell elongation can proceed in the absence of an axoneme, suggesting that a mechanism besides intraflagellar transport emerged to sustain it. RESULTS Here we re...

Cotton (Gossypium herbaceum L.) fiber development consists of a fiber elongation stage (up to 20 d post-anthesis) and a subsequent cell wall thickening stage. Cell wall analysis revealed that the extractable matrix (pectic and hemicellulosic) polysaccharides accounted for 30-50% of total sugar content in the fiber elongation stage but less than 3% in the cell wall thickening stage. By contrast,...

Toxin-resistant polypeptide chain elongation factor 2 cDNA has been cloned from a mutant hamster cell line with only non-ADP-ribosylatable elongation factor 2. The mutation conferring resistance to diphtheria toxin and Pseudomonas aeruginosa exotoxin A is a G-to-A transition in the first nucleotide of codon 717. Codon 715 encodes a histidine residue that is modified post-translationally to diph...

To clarify the role of a number of mRNA processing factors in transcription elongation, we developed an in vivo assay for direct analysis of elongation on chromatin. The assay relies on two substrates containing two G-less cassettes separated by either a long and GC-rich or a short and GC-poor DNA sequence (G-less-based run-on (GLRO) assay). We demonstrate that PAF, THSC/TREX-2, SAGA, the exoso...

Leaf growth in grasses is determined by the cell division and elongation rates, with the duration of cell elongation being one of the processes that is the most sensitive to salinity. Our objective was to investigate the distribution profiles of cell production, cell length and the duration of cell elongation in the growing zone of the wheat leaf during the steady growth phase. Plants were grow...

The synthesis of mature and functional messenger RNA by eukaryotic RNA polymerase II (Pol II) is a complex, multistage process requiring the cooperative action of many cellular proteins. This process, referred to collectively as the transcription cycle, proceeds via five stages: preinitiation, initiation, promoter clearance, elongation, and termination. During the past few years, fundamental st...

During Caenorhabditis elegans development, the process of epidermal elongation converts the bean-shaped embryo into the long thin shape of the larval worm. Epidermal elongation results from changes in the shape of epidermal cells, which in turn result from changes in the epidermal cytoskeleton, the extracellular matrix, and in cell-matrix adhesion junctions. Here, we review the roles of cytoske...

Prion protein is known to have the ability to adopt a pathogenic conformation, which seems to be the basis for protein-only infectivity. The infectivity is based on self-replication of this pathogenic prion structure. One of possible mechanisms for such replication is the elongation of amyloid-like fibrils. We measured elongation kinetics and thermodynamics of mouse prion amyloid-like fibrils a...