A5001863290- Protist diversity and phylogeny
- Microtubule and mitosis dynamics
- Microbial Community Ecology and Physiology
- Photosynthetic Processes and Mechanisms
- Genetic and Kidney Cyst Diseases
- DNA Repair Mechanisms
- Methane Hydrates and Related Phenomena
- Epigenetics and DNA Methylation
- Bacteriophages and microbial interactions
- Coastal wetland ecosystem dynamics
- Various Chemistry Research Topics
- Marine Toxins and Detection Methods
- Developmental Biology and Gene Regulation
- Nuclear Structure and Function
- Animal Genetics and Reproduction
- Trace Elements in Health
- Algal biology and biofuel production
- Glycosylation and Glycoproteins Research
- Environmental DNA in Biodiversity Studies
- Geology and Paleoclimatology Research
- Chromosomal and Genetic Variations
- Telomeres, Telomerase, and Senescence
- Legume Nitrogen Fixing Symbiosis
- Marine Invertebrate Physiology and Ecology
- Polar Research and Ecology
St. Olaf College
2012-2025
Cornell University
1991-2023
Lake Forest College
2008
Texas A&M University
1999
SynZyme Technologies (United States)
1999
University of Chicago
1998
University of Iowa
1987-1991
Beth Israel Deaconess Hospital
1983
Harvard University
1983
University of Washington
1982
Mating Tetrahymena thermophila were bombarded with ribosomal DNA-coated particles at various times in development. Both macronuclear and micronuclear transformants recovered. Optimal developmental stages for transformation occurred during meiosis the micronucleus anlagen formation macronucleus. Evidence is given transient retention of introduced plasmid. Genetic molecular tests confirmed that sexually heritable was associated integration homologous site recipient chromosome.
A detailed mapping and description of campaniform sensilla on the wing haltere Drosophila melanogaster is provided. Six types are distinguished. Similarities in pattern their distribution dorsal ventral surfaces each appendage, as well between haltere, apparent. These data used to assess quality homeotic transformation several mutants bithorax complex which halteres transformed into wings. Flies homozygous for abxbx3pbx produce a complete inventory appendage. In abx, bx3 bx3pbx homozygotes...
We explored how the number of structures is determined in an intracellular organelle series. In Tetrahymena, oral apparatus contains three diagonal ciliary rows: M1, M2, and M3. During development, M rows emerge by sequential segmentation a group basal bodies, starting with longest most anterior M1 ending shortest posterior The mpD-1 mpH-1 alleles increase decrease rows, respectively. identify MpH as TPR protein MpD importin-9. Both proteins localize to form concentration gradients. row...
During sexual reproduction, the freshwater ciliate Tetrahymena thermophila sheds membrane-bound vesicles into extracellular environment (cEMVs: ciliary micro-vesicles). We provide evidence that 100 nm shed from cilia of starved cells promote mating between complementary types. A proteomic analysis revealed these EMVs are decorated with mating-type proteins expressed MAT locus, define a cell’s sex (one seven). Once junction is established cells, smaller 60 (junction vesicles) appear within...
Recombinant human PRL was produced in a murine C127 cell expression system and purified to greater than 97% homogeneity using anion cation exchange chromatography. This material biologically equivalent pituitary-derived both an enzyme-linked immunosorbent assay the Nb2 lymphoma proliferation assay. The predominant forms were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis immunoblotting as being 23 25 kilodaltons (kDa). These mass values confirmed electrospray...
We set out to find the "fenestrin" gene, a gene whose protein is associated with numerous cellular apertures, including nuclear exchange junction in mating Tetrahymena thermophila. First we developed protocols for imaging and isolating intact junctions from conjugating cells. Proteins these were purified using SDS-PAGE, subjected limited proteolysis, precise molecular weights determined by mass spectrometry. Using Protein Prospector software published Genome Database, genes 15 of most...
The histories of 292 people referred for psychiatric assessment after compensable injury are reviewed. It was found that most were suffering from neurotic disorders, notably anxiety states and reactive depressions. Hysterical reactions to be commonest amongst the immigrant population, unskilled poorly educated. Psychoses brain damage mentioned. problem accident neurosis Its relationship hysteria malingering is discussed. concluded many social problems Injured have been obscured in past,...
Conjugation in the freshwater ciliateTetrahymena thermophilainvolves a developmental program that models meiosis, fertilization, and early events characteristic of multicellular eukaryotes. We describe gallery five early-acting conjugation mutations. These mutants,cnj1–5,exhibit phenotypes which specific steps conjugal pathway have been altered or eliminated. Specifically,cnj1andcnj2fail to condense their micronuclear chromatin prior each three prezygotic nuclear divisions. This results...
A new method of inducing self-fertilization, uniparental cytogamy, yields homozygous germinal and somatic genotypes in the ciliate Tetrahymena thermophila. Progeny are highly fertile show a marked tendency for precocious sexual maturity. This is effective protocols designed to generate express nonlethal dominant or recessive mutations.
Genetic analysis of regulated exocytosis can be accomplished in ciliates, since mutants defective stimulus-dependent secretion dense-core vesicles identified. In Tetrahymena thermophila, wild-type cells result their encapsulation by the proteins released from vesicle cores. Cells with defects were isolated mutagenized homozygous that generated using a highly efficient method. Screening was based both on visual assay for encapsulation, and novel panning step differential centrifugation to...
ABSTRACT The ciliated protozoan Tetrahymena thermophila contains two distinct nuclei within a single cell—the mitotic micronucleus and the amitotic macronucleus. Although microtubules are required for proper division of both nuclei, macronuclear chromosomes lack centromeres role in has not been established. Here we describe nuclear defects cells expressing mutant β-tubulin allele that confers hypersensitivity to microtubule-stabilizing drug paclitaxel. Macronuclear is profoundly affected by...
ABSTRACT We describe a novel pair of nested genes, CDA12 and CDA13 , from Tetrahymena thermophila . Both are implicated in membrane trafficking associated with cell division conjugation. Green fluorescent protein localization reveals Cda12p decoration diverse membrane-bound compartments, including mobile, subcortical tubulovesicular compartments; perinuclear vesicles; candidates for recycling endosomes. Cda13p decorates intracellular foci located adjacent to cortically aligned mitochondria...
ABSTRACT Using serial-section transmission electron microscopy and three-dimensional (3D) tomography, we characterized membrane dynamics that accompany the construction of a nuclear exchange junction between mating cells in ciliate Tetrahymena thermophila . Our methods revealed number previously unknown features. (i) Membrane fusion is initiated by extension hundreds 50-nm-diameter protrusions from plasma membrane. These extend both across intercellular space to fuse with partner. (ii)...
Abstract The central nervous system of the sessile barnacle, Semibalanus cariosus (Pallas), has been studied with particular aim determining locations neuron somata in relation to peripheral nerves. This was accomplished by tracing nerves using dissection and methylene blue staining techniques, histological methods, permitting cobaltous chloride diffuse via axons into ganglia (“backfilling”). maps resulting from study reveal some well‐defined sub‐systems, a considerable degree functional...
The ancestral gamete fusion protein, HAP2/GCS1, plays an essential role in fertilization a broad range of taxa. To identify factors that may regulate HAP2/GCS1 activity, we screened mutants the ciliate
Genetic studies on the protist, Tetrahymena thermophila provide a glimpse into unexpectedly rich world of intracellular patterning that unfolds within ciliate cell cortex. Ciliate pattern useful counterpoint to animal models formation in unicellular model draws attention away from fields cells (or nuclei) as principal players metazoan paradigm, focusing instead ciliated basal bodies serving sources positional information. In this study, we identify JANA, Polo kinase Tetrahymena, serves an...
RAD51, the eukaryote homolog of Escherichia coli recA recombinase, participates in homologous recombination during mitosis, meiosis, and repair double-stranded DNA breaks. The Tetrahymena thermophila RAD51 gene was recently cloned, vitro activities induction Rad51p following damage were shown to be similar that from other species. This study describes pattern expression both cell cycle conjugation. mRNA abundance is elevated macronuclear S phase vegetative growth with meiotic prophase new...