Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Caenorhabditis elegans (47)
- MicroRNAs (27)
- Gene Expression Regulation, Developmental (15)
- Caenorhabditis elegans Proteins (14)
- Mutation (7)
-
- Cell Cycle (5)
- Nuclear Proteins (5)
- RNA, Helminth (5)
- MicroRNA (4)
- Signal Transduction (4)
- Transcription Factors (4)
- *Genes, Helminth (3)
- DNA-Binding Proteins (3)
- Gene Expression Regulation (3)
- Gene Regulatory Networks (3)
- *Gene Expression Regulation, Developmental (2)
- Carrier Proteins (2)
- Cell Differentiation (2)
- Drosophila (2)
- Drosophila melanogaster (2)
- Genetics (2)
- Metamorphosis, Biological (2)
- Models, Biological (2)
- Phenotype (2)
- *Feedback, Physiological (1)
- *Immunity, Innate (1)
- *Phenotype (1)
- 3’UTR (1)
- ALG-1 (1)
- Alleles (1)
- Publication Year
- File Type
Articles 61 - 68 of 68
Full-Text Articles in Life Sciences
Molecular Cloning Of Lin-29, A Heterochronic Gene Required For The Differentiation Of Hypodermal Cells And The Cessation Of Molting In C.Elegans, A. Papp, A. Rougvie, Victor Ambros
Molecular Cloning Of Lin-29, A Heterochronic Gene Required For The Differentiation Of Hypodermal Cells And The Cessation Of Molting In C.Elegans, A. Papp, A. Rougvie, Victor Ambros
Victor R. Ambros
The lin-29 gene product of C.elegans activates a temporal developmental switch for hypodermal cells. Loss-of-function lin-29 mutations result in worms that fail to execute a stage-specific pattern of hypodermal differentiation that includes exist from the cell cycle, repression of larval cuticle genes, activation of adult cuticle genes, and the cessation of molting. Combined genetic and physical mapping of restriction fragment length polymorphisms (RFLPs) was used to identify the lin-29 locus. A probe from the insertion site of a Tc1 (maP1), closely linked and to the left of lin-29 on the genetic map, was used to identify a large set of …
Heterochronic Genes Control The Stage-Specific Initiation And Expression Of The Dauer Larva Developmental Program In Caenorhabditis Elegans, Zhongchi Liu, Victor R. Ambros
Heterochronic Genes Control The Stage-Specific Initiation And Expression Of The Dauer Larva Developmental Program In Caenorhabditis Elegans, Zhongchi Liu, Victor R. Ambros
Victor R. Ambros
We report that a stage-specific developmental program, dauer larva formation, is temporally regulated by four heterochronic genes, lin-4, lin-14, lin-28, and lin-29. The effects of mutations in these four genes on dauer larva formation have revealed that they regulate two different processes of dauer larva formation: (1) a decision specifying the larval stage at which dauer larva development initiates, and (2) the specialized differentiation of hypodermal cells during dauer larva morphogenesis. Epistasis analysis has suggested a model in which lin-4 negatively regulates lin-14, and the resulting temporal decrease in lin-14 activity specifies the stage of dauer larva initiation. Our results …
A New Kind Of Informational Suppression In The Nematode Caenorhabditis Elegans, Jonathan Hodgekin, Andrew Papp, Rock Pulak, Victor Ambros, Philip Anderson
A New Kind Of Informational Suppression In The Nematode Caenorhabditis Elegans, Jonathan Hodgekin, Andrew Papp, Rock Pulak, Victor Ambros, Philip Anderson
Victor R. Ambros
Independent reversions of mutations affecting three different Caenorhabditis elegans genes have each yielded representatives of the same set of extragenic suppressors. Mutations at any one of six loci act as allele-specific recessive suppressors of certain allels of unc-54 (a myosin heavy chain gene), lin-29 (a heterochronic gene), and tra-2 (a sex determination gene). The same mutations also suppress certain alleles of another sex determination gene, tra-1, and of a morphogenetic gene, dpy-5. In addition to their suppression phenotype, the suppressor mutations cause abnormal morphogenesis of the male bursa and the hermaphrodite vulva. We name these genes smg-1 through smg-6 (suppressor …
A Hierarchy Of Regulatory Genes Controls A Larva-To-Adult Developmental Switch In C. Elegans, Victor Ambros
A Hierarchy Of Regulatory Genes Controls A Larva-To-Adult Developmental Switch In C. Elegans, Victor Ambros
Victor R. Ambros
The heterochronic genes lin-4, lin-14, lin-28, and lin-29 control the timing of specific postembryonic developmental events in C. elegans. The experiments described here examine how these four genes interact to control a particular stage-specific event of the lateral hypodermal cell lineages. This event, termed the "larva-to-adult switch" (L/A switch), involves several coordinate changes in the behavior of hypodermal cells at the fourth molt: cessation of cell division, formation of adult (instead of larval) cuticle, cell fusion, and cessation of the molting cycle. The phenotypes of multiply mutant strains suggest a model wherein the L/A switch is controlled by the stage-specific …
Molecular Genetics Of The Caenorhabditis Elegans Heterochronic Gene Lin-14, Gary Ruvkun, Victor Ambros, Alan Coulson, Robert Waterston, John Sulston, H. Horvitz
Molecular Genetics Of The Caenorhabditis Elegans Heterochronic Gene Lin-14, Gary Ruvkun, Victor Ambros, Alan Coulson, Robert Waterston, John Sulston, H. Horvitz
Victor R. Ambros
We describe a general strategy for the genetic mapping in parallel of multiple restriction fragment length polymorphism (RFLP) loci. This approach allows the systematic identification for cloning of physical genetic loci within about 100 kb of any gene in Caenorhabditis elegans. We have used this strategy of parallel RFLP mapping to clone the heterochronic gene lin-14, which controls the timing and sequence of many C. elegans postembryonic developmental events. We found that of about 400 polymorphic loci in the C. elegans genome associated with the Tc1 family of repetitive elements, six are within 0.3 map unit of lin-14. The three …
The Lin-14 Locus Of Caenorhabditis Elegans Controls The Time Of Expression Of Specific Postembryonic Developmental Events, Victor R. Ambros, H. Robert Horvitz
The Lin-14 Locus Of Caenorhabditis Elegans Controls The Time Of Expression Of Specific Postembryonic Developmental Events, Victor R. Ambros, H. Robert Horvitz
Victor R. Ambros
The lin-14 locus of Caenorhabditis elegans plays an important role in specifying the normal timing and sequence of developmental events in the lateral hypodermal cell lineages. The results of gene dosage, complementation, and temperature-shift experiments indicate that the fates expressed by cells at successive stages of these cell lineages are specified by the level of lin-14 activity and that lin-14 acts at multiple times during development to control stage-specific choices of cell fate. Our observations suggest that during normal development a reduction in the level of lin-14 gene function causes the sequential expression of stage-specific cell fates.
Heterochronic Mutants Of The Nematode Caenorhabditis Elegans, Victor Ambros, R. Horvitz
Heterochronic Mutants Of The Nematode Caenorhabditis Elegans, Victor Ambros, R. Horvitz
Victor R. Ambros
Mutations in the Caenorhabditis elegans genes lin-14, lin-28, and lin-29 cause heterochronic developmental defects: the timing of specific developmental events in several tissues is altered relative to the timing of events in other tissues. These defects result from temporal transformations in the fates of specific cells, that is, certain cells express fates normally expressed by cells generated at other developmental stages. The identification and characterization of genes that can be mutated to cause heterochrony support the proposal that heterochrony is a mechanism for phylogenetic change and suggest cellular and genetic bases for heterochronic variation.
Surface Ruffles As Markers For Studies Of Cell Transformation By Rous Sarcoma Virus, Victor R. Ambros, Lan Bo Chen, John M. Buchanan
Surface Ruffles As Markers For Studies Of Cell Transformation By Rous Sarcoma Virus, Victor R. Ambros, Lan Bo Chen, John M. Buchanan
Victor R. Ambros
Confluent chick embryo fibroblasts infected with the Ts68 mutant of Rous sarcoma virus were examined by scanning electron microscopy at the permissive (36 degrees) and nonpermissive (41 degrees) temperatures for transformation. Infected cells shifted from 41 degrees to 36 degrees undergo a change in shape from elongated to rounded. This process is preceded by the appearance of surface ruffles on the cell. These surface ruffles are not observed on cells maintained at 41 degrees, appear as early as 0.5 hr after a shift to 36 degrees, and are common on cells maintained at 36 degrees. By 3.5 hr after the …