Life Sciences Commons^™

Function Of Mentzelia Nuda (Loasaceae) Postfloral Nectaries In Seed Defense, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Mentzelia nuda is a coarse, short-lived perennial of the High Plains of North America. The flowers secrete nectar which serves as an attractant for pollinating bees. Postfloral nectar secretion attracts ants whose presence significantly enhances seed set. This is the first demonstration of advantage to postflowering activity of a floral nectary.

Intercellular Communication In Plants: Evidence For A Rapidly Generated, Bidirectionally Transmitted Wound Signal, Eric Davies, Anne Schuster

School of Biological Sciences: Faculty Publications

Wounding (whether by excision, abrasion, or puncture) elicited rapid, massive, and enduring formation of polysomes in aged pea stems and other mature tissues. The response depended on temperature and severity of wounding but not on water uptake, and it occurred in tissues adjacent to, distant from, above, and below the site of injury. The kinetics of polysome formation were similar in tissues adjacent to or up to 150 mm distant from the point of injury. The wound-induced increases in proteinsynthesizing capacity of the polysomes both in vivo and in vitro were much greater than the increases in rRNA and poly(A) …

Analysis Of A Controlling-Element Mutation At The Adh Locus Of Maize, John Osterman, Drew Schwartz

School of Biological Sciences: Faculty Publications

A Ds-suppressed Adh mutant was isolated by the allyl alcohol pollen selection

technique. The mutant produces a reduced level of an altered thermolabile

enzyme suggesting that the Ds element is inserted in the Adh structural gene.

The mutant protein is enzymatically active and does not differ detectably in

size from the progenitor protein. A number of possible explanations for the data

are presented.

Lavender, A Chick Melanocyte Mutant With Defective Melanosome Translocation: A Possible Role For 10 Nm Filaments And Microfilaments But Not Microtubules, Paula Mayerson, John Brumbaugh

School of Biological Sciences: Faculty Publications

Lavender is a mutation of chick neural-crest-derived melanocytes showing dilute feather pigmentation. This defect, previously attributed to a lack or attenuation of dendrites, was found to be due to a defect in melanosome translocation. The mutant phenotype, of melanincongested perikarya and pigmentless dendrites is expressed both in vivo and in vitro. Studies with colcemid and cytochalasin B suggest that the avian melanocyte resembles a dispersing amphibian melanophore in its requirement for microfilaments but not microtubules.
Ultrastructural analysis revealed a normal complement of intracellular filaments. Microtubules, however, are scarce. Intermediate (10 nm) filaments surround and are closely associated with intracellular organelles, …

Lavender, A Chick Melanocyte Mutant With Defective Melanosome Translocation: A Possible Role For 10 Nm Filaments And Microfilaments But Not Microtubules, Paula L. Mayerson, John A. Brumbaugh

School of Biological Sciences: Faculty Publications

Lavender is a mutation of chick neural-crest-derived melanocytes showing dilute feather pigmentation. This defect, previously attributed to a lack or attenuation of dendrites, was found to be due to a defect in melanosome translocation. The mutant phenotype, of melanincongested perikarya and pigmentless dendrites is expressed both in vivo and in vitro. Studies with colcemid and cytochalasin B suggest that the avian melanocyte resembles a dispersing amphibian melanophore in its requirement for microfilaments but not microtubules.

Ultrastructural analysis revealed a normal complement of intracellular filaments. Microtubules, however, are scarce. Intermediate (10 nm) filaments surround and are closely associated with intracellular …

Cover Of Plants With Extrafloral Nectaries At Four Northern California Sites, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Percent cover of plants with extrafloral nectaries was investigated in three California habitats with the same physiognomy as habitats previously studied in Nebraska (perennial native grassland, riparian forest, deciduous forest). In contrast to Nebraska where cover of plants with extrafloral nectaries reached 14 percent, no plants with extrafloral nectaries were found in any California transect. Chaparral was also studied; no plants with extrafloral nectaries were found.