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Genetics and Genomics

Selected Works

1999

Articles 1 - 9 of 9

Full-Text Articles in Life Sciences

The Lin-4 Regulatory Rna Controls Developmental Timing In Caenorhabditis Elegans By Blocking Lin-14 Protein Synthesis After The Initiation Of Translation, Philip Olsen, Victor Ambros Dec 1999

The Lin-4 Regulatory Rna Controls Developmental Timing In Caenorhabditis Elegans By Blocking Lin-14 Protein Synthesis After The Initiation Of Translation, Philip Olsen, Victor Ambros

Victor R. Ambros

lin-4 encodes a small RNA that is complementary to sequences in the 3' untranslated region (UTR) of lin-14 mRNA and that acts to developmentally repress the accumulation of LIN-14 protein. This repression is essential for the proper timing of numerous events of Caenorhabditis elegans larval development. We have investigated the mechanism of lin-4 RNA action by examining the fate of lin-14 mRNA in vivo during the time that lin-4 RNA is expressed. Our results indicate that the rate of synthesis of lin-14 mRNA, its state of polyadenylation, its abundance in the cytoplasmic fraction, and its polysomal sedimentation profile do not …

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Monogenic Control Of Iris Coloration In The January Tetra (Hemigrammus Hyanuary Characidae), Jack Frankel Nov 1999

Monogenic Control Of Iris Coloration In The January Tetra (Hemigrammus Hyanuary Characidae), Jack Frankel

Jack Frankel

The January tetra (Hemigrammus hyanuary Durbin) exhibits two eye color phenotypes. These have a silver iris, which is characteristic of the species, and a green color variant. Segregation patterns observed in the progenies from 12 different crosses support an hypothesis for the monogenic inheritance of iris coloration in this species.

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The Timing Oflin-4rna Accumulation Controls The Timing Of Postembryonic Developmental Events Incaenorhabditis Elegans, Rhonda Feinbaum, Victor Ambros May 1999

The Timing Oflin-4rna Accumulation Controls The Timing Of Postembryonic Developmental Events Incaenorhabditis Elegans, Rhonda Feinbaum, Victor Ambros

Victor R. Ambros

The lin-4 gene encodes a small RNA that is required to translationally repress lin-14 toward the end of the first larval stage of Caenorhabditis elegans development. To determine if the timing of LIN-14 protein down-regulation depends on the temporal profile of lin-4 RNA level, we analyzed the stage-specificity of lin-4 RNA expression during wild-type development and examined the phenotypes of transgenic worms that overexpress lin-4 RNA during the first larval stage. We found that lin-4 RNA first becomes detectable at approximately 12 h of wild-type larval development and rapidly accumulates to nearly maximum levels by 16 h. This profile of …

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Cell Cycle-Dependent Sequencing Of Cell Fate Decisions In Caenorhabditis Elegans Vulva Precursor Cells, Victor Ambros Apr 1999

Cell Cycle-Dependent Sequencing Of Cell Fate Decisions In Caenorhabditis Elegans Vulva Precursor Cells, Victor Ambros

Victor R. Ambros

In Caenorhabditis elegans, the fates of the six multipotent vulva precursor cells (VPCs) are specified by extracellular signals. One VPC expresses the primary (1 degrees ) fate in response to a Ras-mediated inductive signal from the gonad. The two VPCs flanking the 1 degrees cell each express secondary (2 degrees ) fates in response to lin-12-mediated lateral signaling. The remaining three VPCs each adopt the non-vulval tertiary (3 degrees ) fate. Here I describe experiments examining how the selection of these vulval fates is affected by cell cycle arrest and cell cycle-restricted lin-12 activity. The results suggest that lin-12 participates …

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Genome-Wide Bioinformatic And Molecular Analysis Of Introns In Saccharomyces Cerevisiae, Marc Spingola, Leslie Grate, David Haussler, Manuel Ares Jan 1999

Genome-Wide Bioinformatic And Molecular Analysis Of Introns In Saccharomyces Cerevisiae, Marc Spingola, Leslie Grate, David Haussler, Manuel Ares

Marc Spingola

Introns have typically been discovered in an ad hoc fashion: introns are found as a gene is characterized for other reasons. As complete eukaryotic genome sequences become available, better methods for predicting RNA processing signals in raw sequence will be necessary in order to discover genes and predict their expression. Here we present a catalog of 228 yeast introns, arrived at through a combination of bioinformatic and molecular analysis. Introns annotated in the Saccharomyces Genome Database (SGD) were evaluated, questionable introns were removed after failing a test for splicing in vivo, and known introns absent from the SGD annotation were …

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Diversity And Molecular Evolution Of The Rps2 Resistance Gene In Arabidopsis Thaliana, Ana Lucia Caicedo Jan 1999

Diversity And Molecular Evolution Of The Rps2 Resistance Gene In Arabidopsis Thaliana, Ana Lucia Caicedo

Ana Lucia Caicedo

The RPS2 gene in Arabidopsis thaliana governs resistance to strains of the bacterial pathogen, Pseudomonas syringae pv. tomato, that express the avrRpt2 gene. The two loci are involved in a gene-for-gene interaction. Seventeen accessions of A. thaliana were sequenced to explore the diversity present in the coding region of the RPS2 locus. An unusually high level of nucleotide polymorphisms was found (1.26%), with nearly half of the observed polymorphisms resulting in amino acid changes in the RPS2 protein. Seven haplotypes (alleles) were identified and their evolutionary relationships deduced. Several of the alleles conferring resistance were found to be closely related, …

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Photoreceptor Dysplasia (Pd) In Miniature Schnauzer Dogs: Evaluation Of Candidate Genes By Molecular Genetic Analysis, Qi Zhang, V J. Baldwin, Gregory M. Acland, C J. Parshall, J. Haskell, Gustavo D. Aguirre, Kunal Ray Dec 1998

Photoreceptor Dysplasia (Pd) In Miniature Schnauzer Dogs: Evaluation Of Candidate Genes By Molecular Genetic Analysis, Qi Zhang, V J. Baldwin, Gregory M. Acland, C J. Parshall, J. Haskell, Gustavo D. Aguirre, Kunal Ray

Gustavo D. Aguirre, VMD, PhD

Photoreceptor dysplasia (pd) is one of a group of at least six distinct autosomal and one X-linked retinal disorders identified in dogs which are collectively known as progressive retinal atrophy (PRA). It is an early onset retinal disease identified in miniature schnauzer dogs, and pedigree analysis and breeding studies have established autosomal recessive inheritance of the disease. Using a gene-based approach, a number of retina-expressed genes, including some members of the phototransduction pathway, have been causally implicated in retinal diseases of humans and other animals. Here we examined seven such potential candidate genes (opsin, RDS/peripherin, ROM1, rod cGMP-gated cation channel …

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Overview Of The International Workshop On Canine Genetics, Gustavo D. Aguirre, Kunal Ray, Gregory M. Acland Dec 1998

Overview Of The International Workshop On Canine Genetics, Gustavo D. Aguirre, Kunal Ray, Gregory M. Acland

Gustavo D. Aguirre, VMD, PhD

No abstract provided.

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The Genetics And Evolution Of The Mariner Transposable Element In Drosophila Simulans: Worldwide Distribution And Experimental Population Dynamics, Amy L. Russell, R. C. Woodruff Dec 1998

The Genetics And Evolution Of The Mariner Transposable Element In Drosophila Simulans: Worldwide Distribution And Experimental Population Dynamics, Amy L. Russell, R. C. Woodruff

Amy L. Russell

We have studied both the frequency and biogeographical distribution of the transposable DNA element mariner in natural populations of Drosophila simulans and the short-term evolutionary characteristics of mariner in experimental populations. The mariner element has been identified in natural populations of D. simulans from Africa, Europe, the Middle East, Japan, Australia, several Pacific islands, North America, and South America. Only four lines out of 296 were devoid of active mariner elements, as measured by the presence of functional mariner transposase. A slight correlation was found between the latitudinal coordinate of the collection sites and the level of mariner activity in …

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