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Articles 1 - 8 of 8
Full-Text Articles in Life Sciences
The Characterization Of Ribosomal Rna Gene Chromatin From Physarum Polycephalum, Sally A. Amero, Vicky L. Montoya, Wendy L. Murdoch, Roy C. Ogle, John L. Keating, Robert M. Grainger
The Characterization Of Ribosomal Rna Gene Chromatin From Physarum Polycephalum, Sally A. Amero, Vicky L. Montoya, Wendy L. Murdoch, Roy C. Ogle, John L. Keating, Robert M. Grainger
Medical Diagnostics & Translational Sciences Faculty Publications
We have isolated ribosomal RNA gene (rDNA) chromatin from Physarum polycephalum using a nucleolar isolation procedure that minimizes protein loss from chromatin and, subsequently, either agarose gel electrophoresis or metrizamide gradient centrifugation to purify this chromatin fraction (Amero, S. A., Ogle, R. C., Keating, J. L., Montoya, V. L., Murdoch, W. L., and Grainger, R. M. (1988) J. Biol. Chem. 263, 10725-10733). Metrizamide-purified rDNA chromatin obtained from nucleoli isolated according to the new procedure has a core histone/DNA ratio of 0.77:1. The major core histone classes comigrate electrophoretically with their nuclear counterparts on Triton-acid-urea/sodium dodecyl sulfate two-dimensional gels, although they …
Environmental Effects On Remating In Drosophila Melanogaster, Lawrence G. Harshman, Ary A. Hoffman, Timothy Prout
Environmental Effects On Remating In Drosophila Melanogaster, Lawrence G. Harshman, Ary A. Hoffman, Timothy Prout
Lawrence G. Harshman Publications
The effects of density and food on remating were investigated using Drosophila melanogaster. The frequency of remating was unaffected by density for some combinations of fly strains but was reduced at low relative densities for other combinations. Until females had used most of their stored sperm, remating was less likely when food was absent or contact with food was prevented. Food availability had little effect on the incidence of remating once stored sperm were depleted and had no effect on initial virgin mating frequency. This study indicates that environmental factors can have a substantial direct influence on the frequency …
International Registry Of Poultry Genetic Stocks, Ralph G. Somes Jr.
International Registry Of Poultry Genetic Stocks, Ralph G. Somes Jr.
Storrs Agricultural Experiment Station
No abstract provided.
Genic Studies Of Lasiurus (Chiroptera: Vespertilionidae), Robert J. Baker, John C. Patton, Hugh H. Genoways, John W. Bickham
Genic Studies Of Lasiurus (Chiroptera: Vespertilionidae), Robert J. Baker, John C. Patton, Hugh H. Genoways, John W. Bickham
University of Nebraska State Museum: Mammalogy Papers
Bats of the genus Lasiurus present a number of interesting systematic problems that are difficult to resolve by traditional techniques. Members of the genus share a suite of derived morphological (Hall and Jones, 1961; Handley , 1960) and karyotypic (Bickham 1979, 1988) characteristics. However, until 1960 (Handley, 1960), members were placed in two genera- Lasiurus and Dasypterus-based primarily upon the presence or absence of the small, first upper premolar. Handley (1960) analyzed the differences and similarities among these two genera and concluded they were not distinct even at a subgeneric level. One goal of this study was to provide …
Truncation Of Screwworm (Diptera: Calliphoridae) Development By Irradiation Of Embryos., David B. Taylor, Robert L. Mangan
Truncation Of Screwworm (Diptera: Calliphoridae) Development By Irradiation Of Embryos., David B. Taylor, Robert L. Mangan
David B Taylor
Gamma irradiation of screwworm, Cochliomyia hominivorax (Coquerel), embryos was used to truncate the life cycle at the prepupal stage. Egg hatch and larval survival were not reduced by dosages ≤8 kilorads (kr). Pupariation and adult emergence were inhibited by dosages ≥2.8 and 1.2 kr, respectively. Larvae, irradiated as embryos with dosages ≤8 kr, successfully infested wounded sheep, although larval weight was lower than normal. A dosage of 5.8 kr was sufficient to prevent pupariation, while permitting larval development to the third instar. Truncation of screwworm development permits the use of artificially wounded and infested animals for screwworm population surveillance and …
The Purification Of Ribosomal Rna Gene Chromatin From Physarum Polycephalum, Sally A. Amero, Roy C. Ogle, John L. Keating, Vicky L. Montoya, Wendy L. Murdoch, Robert M. Grainger
The Purification Of Ribosomal Rna Gene Chromatin From Physarum Polycephalum, Sally A. Amero, Roy C. Ogle, John L. Keating, Vicky L. Montoya, Wendy L. Murdoch, Robert M. Grainger
Medical Diagnostics & Translational Sciences Faculty Publications
We have undertaken the purification of ribosomal RNA gene (rDNA) chromatin from the slime mold Physarum polycephalum, in order to study its chromatin structure. In this organism rDNA exists in nucleoli as highly repeated minichromosomes, and one can obtain crude chromatin fractions highly enriched in rDNA from isolated nucleoli. We first developed a nucleolar isolation method utilizing polyamines as stabilization agents that results in a chromatin fraction containing far more protein than is obtained by the more commonly used divalent cation isolation methods. The latter method appears to result in extensive histone loss during chromatin isolations. Two methods were then …
Hybridization Of Aedes (Protomacleaya) Zoosophus With Ae. (Pro.) Triseriatus Group Species: Hybrid Morphology, David Taylor
Hybridization Of Aedes (Protomacleaya) Zoosophus With Ae. (Pro.) Triseriatus Group Species: Hybrid Morphology, David Taylor
David B. Taylor
Morphology of hybrids between Aedes (Protomacleaya) zoosophus and Ae. (Pro.) triseriatus group species is described. Adult females of hybrids key to Ae. zoosophus. Hybrids are differentiated from Ae. zoosophus by the dark longitudinal medial or submedial lines on the thorax and by the reduced width of the light tarsal and abdominal bands. The transverse band of light scales on the anterior scutum is complete in Ae. hendersoni / Ae. zoosophus hybrids and incomplete in Ae. triseriatus / Ae. zoosophus hybrids. Aedes brelandi / Ae. zoosophus hybrids are similar to Ae. hendersoni / Ae. zoosophus hybrids. However, due to the …
Truncation Of Screwworm (Diptera: Calliphoridae) Development By Irradiation Of Embryos., David Taylor, Robert Mangan
Truncation Of Screwworm (Diptera: Calliphoridae) Development By Irradiation Of Embryos., David Taylor, Robert Mangan
David B. Taylor
Gamma irradiation of screwworm, Cochliomyia hominivorax (Coquerel), embryos was used to truncate the life cycle at the prepupal stage. Egg hatch and larval survival were not reduced by dosages ≤8 kilorads (kr). Pupariation and adult emergence were inhibited by dosages ≥2.8 and 1.2 kr, respectively. Larvae, irradiated as embryos with dosages ≤8 kr, successfully infested wounded sheep, although larval weight was lower than normal. A dosage of 5.8 kr was sufficient to prevent pupariation, while permitting larval development to the third instar. Truncation of screwworm development permits the use of artificially wounded and infested animals for screwworm population surveillance and …