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Full-Text Articles in Life Sciences
Differential Gene Expression In Insects: Transcriptional Control, Lawrence G. Harshman, Anthony A. James
Differential Gene Expression In Insects: Transcriptional Control, Lawrence G. Harshman, Anthony A. James
School of Biological Sciences: Faculty Publications
Studies on transcriptional control of gene expression play a pivotal role in many areas of biology. In non-Drosophilid insects, the cuticle, chorion, immune response, silk gland, storage proteins, and vitellogenin are foci for advances in basic research on promoter elements and transcription factors. Insects offer other advantages for gene regulation studies, including the availability of applied problems. In non-Drosophilid insects, the most serious problem for transcriptional control studies is the lack of homologous in vivo expression systems. Once this deficiency is addressed, the full impact of research on transcription control will be realized throughout the field of entomology.
Evolutionary Change In A Receiver Bias: A Comparison Of Female Preference Functions, Alexandra Basolo
Evolutionary Change In A Receiver Bias: A Comparison Of Female Preference Functions, Alexandra Basolo
School of Biological Sciences: Faculty Publications
Female poeciliid fishes of the sister genera Xiphophorus and Priapella share a preference for males with swords, despite phylogenetic information suggesting that swords arose in Xiphophorus after the divergence of the two genera. This study examines the strength of sword and body-size preferences in a representative of both genera. A comparison of the preference functions reveals that the strength of the preference favoring a sword in P. olmecae is significantly stronger than that in X. helleri. This result demonstrates that the pre-existing bias is not evolutionarily fixed, and that there has been change in the bias favoring the sword, …
Molecular Characterization Of The Α-Glucosidase Gene (Mala) From The Hyperthermophilic Archaeon Sulfolobus Solfataricus, Michael Rolfsmeier, Cynthia Haseltine, Elisabetta Bini, Amy Clark, Paul H. Blum
Molecular Characterization Of The Α-Glucosidase Gene (Mala) From The Hyperthermophilic Archaeon Sulfolobus Solfataricus, Michael Rolfsmeier, Cynthia Haseltine, Elisabetta Bini, Amy Clark, Paul H. Blum
School of Biological Sciences: Faculty Publications
Acidic hot springs are colonized by a diversity of hyperthermophilic organisms requiring extremes of temperature and pH for growth. To clarify how carbohydrates are consumed in such locations, the structural gene (malA) encoding the major soluble α-glucosidase (maltase) and flanking sequences from Sulfolobus solfataricus were cloned and characterized. This is the first report of an α-glucosidase gene from the archaeal domain. malA is 2,083 bp and encodes a protein of 693 amino acids with a calculated mass of 80.5 kDa. It is flanked on the 5’ side by an unusual 1-kb intergenic region. Northern blot analysis of the …
Roles Of Dnak And Rpos In Starvation-Induced Thermotolerance Of Escherichia Coli, David Rockabrand, Kevin Livers, Tess Austin, Robyn Kaiser, Debra Jensen, Richard Burgess, Paul H. Blum
Roles Of Dnak And Rpos In Starvation-Induced Thermotolerance Of Escherichia Coli, David Rockabrand, Kevin Livers, Tess Austin, Robyn Kaiser, Debra Jensen, Richard Burgess, Paul H. Blum
School of Biological Sciences: Faculty Publications
DnaK is essential for starvation-induced resistance to heat, oxidation, and reductive division in Escherichia coli. Studies reported here indicate that DnaK is also required for starvation-induced osmotolerance, catalase activity, and the production of the RpoS-controlled Dps (PexB) protein. Because these dnaK mutant phenotypes closely resemble those of rpoS (o38) mutants, the relationship between DnaK and RpoS was evaluated directly during growth and starvation at 30°C in strains with genetically altered DnaK content. A starvation-specific effect of DnaK on RpoS abundance was observed. During carbon starvation, DnaK deficiency reduced RpoS levels threefold, while DnaK excess increased RpoS levels …
Life-History Decisions Under Predation Risk: Importance Of A Game Perspective, Amos Bouskila, Michael E. Robinson, Bernard D. Roitberg, Brigitte Tenhumberg
Life-History Decisions Under Predation Risk: Importance Of A Game Perspective, Amos Bouskila, Michael E. Robinson, Bernard D. Roitberg, Brigitte Tenhumberg
School of Biological Sciences: Faculty Publications
We model ontogenetic shifts (e.g. in food or habitat use) during development under predation risk. We ask whether inclusion of state and frequency dependence will provide new insights when compared with game-free life-history theory. We model a simple biological scenario in which a prey animal must switch from a low-predation, low-growth habitat to a high-predation, high-growth habitat. To assess the importance of frequency dependence, we compare the results of four scenarios of increasing complexity: (1) no predation; (2) constant predation; (3) frequency-dependent predation (predation risk diluted at high prey density); and (4) frequency-dependent predation as in (3) but with predators …
Population Biology Of Intraspecific Polyploidy In Grasses, Kathleen H. Keeler
Population Biology Of Intraspecific Polyploidy In Grasses, Kathleen H. Keeler
School of Biological Sciences: Faculty Publications
Polyploidy is the duplication of an entire nuclear genome, whether diploid or higher level (Stebbins, 1971; Thompson & Lumaret, 1992) and a frequent occurrence in plants. Stebbins (1971) estimated that 30-35% of flowering plant species are polyploid, and that many more had a polyploid event in their evolutionary history, including all members of such important families as the Magnoliaceae, Salicaceae, and Ericaceae. Goldblatt (1980) estimated 55%, but probably up to 75%, of monocotyledons had at least one polyploid event in their history, using the criterion that if the species has a base number higher than n=13 it is derived …