A5005089361- Developmental Biology and Gene Regulation
- Congenital heart defects research
- Microtubule and mitosis dynamics
- Cellular Mechanics and Interactions
- Neurobiology and Insect Physiology Research
- Sperm and Testicular Function
- Cellular transport and secretion
- Reproductive Biology and Fertility
- Protist diversity and phylogeny
- Physiological and biochemical adaptations
- Spaceflight effects on biology
- Neurogenesis and neuroplasticity mechanisms
- Photoreceptor and optogenetics research
- Animal Genetics and Reproduction
- Zebrafish Biomedical Research Applications
- Insect Resistance and Genetics
- Genetic and Kidney Cyst Diseases
- Invertebrate Immune Response Mechanisms
- Hypothalamic control of reproductive hormones
- Receptor Mechanisms and Signaling
- Pluripotent Stem Cells Research
- Micro and Nano Robotics
- Caveolin-1 and cellular processes
- Hormonal and reproductive studies
- Hemispheric Asymmetry in Neuroscience
Oregon Health & Science University
2002-2017
University of Portland
1996-2012
Oregon Medical Research Center
2011
Oregon National Primate Research Center
1976-1998
Northwestern University
1998
Texas A&M University
1995
Bowdoin College
1995
University of Minnesota
1995
Wesleyan University
1988-1993
University of California, Irvine
1993
Abstract We show with time-lapse micrography that narrowing in the circumblastoporal dimension (convergence) and lengthening animal-vegetal (extension) of involuting marginal zone (IMZ) noninvoluting (NIMZ) are major tissue movements driving blastopore closure involution IMZ during gastrulation South African clawed frog, Xenopus laevis. Analysis shows degree convergence is uniform from dorsal to ventral sides, whereas extension greater on side gastrula. Expiants gastrula simultaneous NIMZ....
The processes thought to function in Xenopus gastrulation include bottle cell formation, migration of cells on the roof blastocoel, and autonomous convergent extension circumblastoporal region. A review recent classical results shows that only last accounts for bulk tissue displacement gastrulation, including spreading marginal zone toward blastopore, involution zone, closure blastopore. Microsurgical manipulation explantation studies, analysed by time-lapse video cine microscopy, dorsal...
Abstract Morphometric data from scanning electron micrographs (SEM) of cells in intact embryos and high‐resolution time‐lapse recordings cell behavior cultured explants were used to analyze the cellular events underlying morphogenesis notochord during gastrulation neurulation Xenopus laevis . The becomes longer, narrower, thicker as it changes its shape arrangement more are added at posterior end. development fall into three phases. In first phase, occurring late gastrula, become distinct...
Vertebrate embryos define an anatomic plane of bilateral symmetry by establishing rudimentary anteroposterior and dorsoventral (DV) axes. A left-right (LR) axis also emerges, presaging eventual morphological asymmetries the heart other viscera. In radially symmetric egg Xenopus laevis, earliest steps in DV determination are driven microtubule-dependent localization maternal components toward prospective dorsal side. LR is linked time to this DV-determining process, but unclear....
Catecholamines, thought to derive from the extrinsic innervation of ovary, participate in regulation ovarian development and mature gonadal function. Recently, intraovarian neurons containing tyrosine hydroxylase (TH), rate-limiting enzyme catecholamine biosynthesis, were described ovary nonhuman primates. We now show that primate expresses both genes encoding TH dopamine β-hydroxylase (DBH), key enzymes norepinephrine (NE) biosynthesis. Ovarian identified as a site DBH gene expression,...
The ovary of humans and nonhuman primates is innervated by sympathetic sensory neurons the peripheral nervous system. Recent studies demonstrated that density innervation to rhesus monkey developmentally regulated, with adult being attained around time puberty. In present study, we used an immunocytochemical approach obtain insights into cell-cell signaling mechanisms may contribute functional maintenance this innervation. Because system require target-derived neurotropins for their survival...
In dividing Xenopus eggs, furrowing is accompanied by expansion of a new domain plasma membrane in the cleavage plane. The source known to include store oogenetically produced exocytotic vesicles, but site where their exocytosis occurs has not been described. Previous work revealed V-shaped array microtubule bundles at base advancing furrows. Cold shock or exposure nocodazole halted domain, which suggests that these microtubules are involved localized exocytosis. present report, scanning...
ABSTRACT The egg of the frog Xenopus is cylindrically symmetrical about its animal-vegetal axis before fertilization. Midway through first cell cycle, yolky subcortical cytoplasm rotates 30° relative to cortex and plasma membrane, usually toward side sperm entry point. Dorsal embryonic structures always develop on away from which moves. Details deep cytoplasmic movements associated with cortical rotation were studied in eggs vitally stained during oogenesis a yolk platelet-specific...
The mammalian testis is innervated by extrinsic catecholaminergic nerves and responds to catecholamines with steroid secretion. Although the primate has also been shown be innervated, potential differences in density of this innervation between immature sexually developed individuals have not described. A recent study demonstrated that ovary contains a network neuron-like cells some these are catecholaminergic. It thus possible male gonad endowed similar intragonadal source catecholamines....
Our experimental results, as well those of others, lead us to suggest the following steps in dorsalization and axialization Xenopus egg embryo: (1) spermaster determines direction rotation cortex relative deeper cytoplasm (endoplasm ); (2) activates latent dorsalizingaxializing agents vegetal hemisphere. The extent am ount activation. location activated agents. (3) determine level mesoderm-inducing activity cells cleaved from that cytoplasmic region. (4) inducing at least time which marginal...