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Full-Text Articles in Life Sciences
Audition In Sciaenid Fishes With Different Swim Bladder-Inner Ear Configurations, John U. Ramcharitar, Dennis M. Higgs, Arthur N. Popper
Audition In Sciaenid Fishes With Different Swim Bladder-Inner Ear Configurations, John U. Ramcharitar, Dennis M. Higgs, Arthur N. Popper
Biological Sciences Publications
We investigated how morphological differences in the auditory periphery of teleost fishes may relate to hearing capabilities. Two species of western Atlantic sciaenids were examined: weakfish (Cynoscion regalis, Block and Schneider) and spot (Leiostomus xanthurus, Lacepede). These species differ in the anatomical relationship between the swim bladder and the inner ear. In weakfish, the swim bladder has a pair of anterior horns that terminate close to the ear, while there are no extensions of the swim bladder in spot. Thus, the swim bladder in spot terminates at a greater distance from the ear when compared to weakfish. With the use …
Drosophila Cks30a Interacts With Cdk1 To Target Cyclin A For Destruction In The Female Germline, Andrew Swan, Gail Barcelo, Trudi Schüpbach
Drosophila Cks30a Interacts With Cdk1 To Target Cyclin A For Destruction In The Female Germline, Andrew Swan, Gail Barcelo, Trudi Schüpbach
Biological Sciences Publications
Skip to Next Section Cks is a small highly conserved protein that plays an important role in cell cycle control in different eukaryotes. Cks proteins have been implicated in entry into and exit from mitosis, by promoting Cyclin-dependent kinase (Cdk) activity on mitotic substrates. In yeast, Cks can promote exit from mitosis by transcriptional regulation of cell cycle regulators. Cks proteins have also been found to promote S-phase via an interaction with the SCFSkp2 Ubiquitination complex. We have characterized the Drosophila Cks gene, Cks30A and we find that it is required for progression through female meiosis and the mitotic divisions …
Minimizing Invasion Risk By Reducing Propagule Pressure: A Model For Ballast-Water Exchange, Marjorie J. Wonham, Mark A. Lewis, Hugh J. Macisaac
Minimizing Invasion Risk By Reducing Propagule Pressure: A Model For Ballast-Water Exchange, Marjorie J. Wonham, Mark A. Lewis, Hugh J. Macisaac
Biological Sciences Publications
Biological invasions are a major and increasing agent of global biodiversity change. Theory and practice indicate that invasion risk can be diminished by reducing propagule pressure, or the quantity, quality, and frequency of introduced individuals. For aquatic invasions, the primary global invasion pathway is ballast-water transport, and the primary risk reduction strategy is currently open-ocean exchange. Exchange was developed with shipping between freshwater ports in mind, but the majority of shipping connects brackish and marine ports. A worldwide convention, adopted in 2004 by the International Maritime Organization, now mandates ballast-water exchange (or equivalent management) for its 164 member states. Will …
Sex Differences In Singing And Duetting Behavior Of Neotropical Rufous-And-White Wrens (Thryothorus Rufalbus), Daniel J. Mennill, Sandra L. Vehrencamp
Sex Differences In Singing And Duetting Behavior Of Neotropical Rufous-And-White Wrens (Thryothorus Rufalbus), Daniel J. Mennill, Sandra L. Vehrencamp
Biological Sciences Publications
In many tropical bird species, males and females sing together in coordinated vocal duets. Although studies of duetting present unique opportunities for understanding conflict and cooperation between the sexes, very few investigations describe the similarities and differences between male and female singing behaviors. Here, we present the first detailed account of the singing behavior of Rufous-and-white Wrens (Thryothorus rufalbus), a resident tropical duetting songbird. Male and female songs share a similar structure, yet show pronounced sex differences. Male songs have lower frequency characteristics and more repeated trill syllables, and often sound louder than female songs. Males sing more than females, …
Stress Hormones: A Link Between Maternal Condition And Sex‐Biased Reproductive Investment, Oliver P. Love, Eunice H. Chin, Katharine E. Wynne-Edwards, Tony D. Williams
Stress Hormones: A Link Between Maternal Condition And Sex‐Biased Reproductive Investment, Oliver P. Love, Eunice H. Chin, Katharine E. Wynne-Edwards, Tony D. Williams
Biological Sciences Publications
Abstract: In species where offspring fitness is sex‐specifically influenced by maternal reproductive condition, sex allocation theory predicts that poor‐quality mothers should invest in the evolutionarily less expensive sex. Despite an accumulation of evidence that mothers can sex‐specifically modulate investment in offspring in relation to maternal quality, few mechanisms have been proposed as to how this is achieved. We explored a hormonal mechanism for sex‐biased maternal investment by measuring and experimentally manipulating baseline levels of the stress hormone corticosterone in laying wild female European starlings (Sturnus vulgaris) and examining effects on sex ratio and sex‐specific offspring phenotype adjustment. Here we show …
Support For The Immortal Strand Hypothesis: Neural Stem Cells Partition Dna Asymmetrically In Vitro, Phillip Karpowicz, Cindi Morshead, Angela Kam, Eric Jervis, John Ramunas, Vincent Cheng, Derek Van Der Kooy
Support For The Immortal Strand Hypothesis: Neural Stem Cells Partition Dna Asymmetrically In Vitro, Phillip Karpowicz, Cindi Morshead, Angela Kam, Eric Jervis, John Ramunas, Vincent Cheng, Derek Van Der Kooy
Biological Sciences Publications
The immortal strand hypothesis proposes that asymmetrically dividing stem cells (SCs) selectively segregate chromosomes that bear the oldest DNA templates. We investigated cosegregation in neural stem cells (NSCs). After exposure to the thymidine analogue 5-bromo-2-deoxyuridine (BrdU), which labels newly synthesized DNA, a subset of neural precursor cells were shown to retain BrdU signal. It was confirmed that some BrdU-retaining cells divided actively, and that these cells exhibited some characteristics of SCs. This asymmetric partitioning of DNA then was demonstrated during mitosis, and these results were further supported by real time imaging of SC clones, in which older and newly synthesized …
Lens And Retina Formation Require Expression Of Pitx3 In Xenopus Pre-Lens Ectoderm, Farhad Khosrowshahian, Marian Wolanski, Wy Chang, Kazuhiro Fujiki, Larry Jacobs, Michael J. Crawford
Lens And Retina Formation Require Expression Of Pitx3 In Xenopus Pre-Lens Ectoderm, Farhad Khosrowshahian, Marian Wolanski, Wy Chang, Kazuhiro Fujiki, Larry Jacobs, Michael J. Crawford
Biological Sciences Publications
Pitx3 is expressed in tissues fated to contribute to eye development, namely, neurula stage ectoderm and prechordal mesoderm, then presumptive lens ectoderm, placode, and finally lens. Pitx3 overexpression alters lens, optic cup, optic nerve, and diencephalon development. Many of the induced anomalies are attributable to midline deficits; however, as assessed by molecular markers, ectopic Pitx3 appears to temporarily enlarge the lens field. These changes are usually insufficient to generate either ectopic lenses to enlarge the eye that eventually differentiates. Conversely, use of a repressor chimera or of antisense morpholinos alters early expression of marker genes, and later inhibits lens development, …
Caveolin-1 Mediates The Expression And Localization Of Cathepsin B, Pro-Urokinase Plasminogen Activator And Their Cell-Surface Receptors In Human Colorectal Carcinoma Cells, Dora Cavallo-Medved, Jianxin Mai, Julie Dosescu, Mansoureh Sameni, Bonnie F. Sloane
Caveolin-1 Mediates The Expression And Localization Of Cathepsin B, Pro-Urokinase Plasminogen Activator And Their Cell-Surface Receptors In Human Colorectal Carcinoma Cells, Dora Cavallo-Medved, Jianxin Mai, Julie Dosescu, Mansoureh Sameni, Bonnie F. Sloane
Biological Sciences Publications
Cathepsin B and pro-urokinase plasminogen activator (pro-uPA) localize to the caveolae of HCT 116 human colorectal carcinoma cells, an association mediated by active K-RAS. In this study, we established a stable HCT 116 cell line with a gene encoding antisense caveolin-1 (AS-cav-1) to examine the effects of caveolin-1, the main structural protein of caveolae, on the expression and localization of cathepsin B and pro-uPA, and their cell-surface receptors p11 and uPA receptor (uPAR), respectively. AS-cav-1 HCT 116 cells secreted less procathepsin B than control (empty vector) cells as measured by immunoblotting and pepsin activation of the proenzyme. Expression and secretion …