Life Sciences Commons^™

The Caenorhabditis Elegans Heterochronic Regulator Lin-14 Is A Novel Transcription Factor That Controls The Developmental Timing Of Transcription From The Insulin/Insulin-Like Growth Factor Gene Ins-33 By Direct Dna Binding., Marta Hristova, Darcy Birse, Yang Hong, Victor R. Ambros

Victor R. Ambros

A temporal gradient of the novel nuclear protein LIN-14 specifies the timing and sequence of stage-specific developmental events in Caenorhabditis elegans. The profound effects of lin-14 mutations on worm development suggest that LIN-14 directly or indirectly regulates stage-specific gene expression. We show that LIN-14 can associate with chromatin in vivo and has in vitro DNA binding activity. A bacterially expressed C-terminal domain of LIN-14 was used to select DNA sequences that contain a putative consensus binding site from a pool of randomized double-stranded oligonucleotides. To identify candidates for genes directly regulated by lin-14, we employed DNA microarray hybridization to compare …

Developmental Biology. Encountering Micrornas In Cell Fate Signaling., Xantha Karp, Victor Ambros

Victor R. Ambros

Comment on: LIN-12/Notch activation leads to microRNA-mediated down-regulation of Vav in C. elegans. [Science. 2005]

Silencing Of Retrotransposons In Dictyostelium By Dna Methylation And Rnai., Markus Kuhlmann, Branimira E. Borisova, Markus Kaller, Pontus Larsson, Dirk Stach, Jianbo Na, Ludwig Eichinger, Frank Lyko, Victor R. Ambros, Fredrik Soderbom, Christian Hammann, Wolfgang Nellen

Victor R. Ambros

We have identified a DNA methyltransferase of the Dnmt2 family in Dictyostelium that was denominated DnmA. Expression of the dnmA gene is downregulated during the developmental cycle. Overall DNA methylation in Dictyostelium is approximately 0.2% of the cytosine residues, which indicates its restriction to a limited set of genomic loci. Bisulfite sequencing of specific sites revealed that DnmA is responsible for methylation of mostly asymmetric C-residues in the retrotransposons DIRS-1 and Skipper. Disruption of the gene resulted in a loss of methylation and in increased transcription and mobilization of Skipper. Skipper transcription was also upregulated in strains that had genes …

Mesodermally Expressed Drosophila Microrna-1 Is Regulated By Twist And Is Required In Muscles During Larval Growth., Nicholas S. Sokol, Victor R. Ambros

Victor R. Ambros

Although hundreds of evolutionarily conserved microRNAs have been discovered, the functions of most remain unknown. Here, we describe the embryonic spatiotemporal expression profile, transcriptional regulation, and loss-of-function phenotype of Drosophila miR-1 (DmiR-1). DmiR-1 RNA is highly expressed throughout the mesoderm of early embryos and subsequently in somatic, visceral, and pharyngeal muscles, and the dorsal vessel. The expression of DmiR-1 is controlled by the Twist and Mef2 transcription factors. DmiR-1KO mutants, generated using ends-in gene targeting, die as small, immobilized second instar larvae with severely deformed musculature. This lethality is rescued when a DmiR-1 transgene is expressed specifically in the mesoderm …

Digenic Control Of Colouration In The Two-Spot Gourami Trichogaster Trichopterus Trichopterus, Jack Frankel

Jack Frankel

Cgkb-Cyanogroup Genomics Knowledge Base, Tin-Chun Chu, Lee Lee, Shankar Srinivasan, John Gaynor, Quinn Vega, Bonnie Lustigman

Tin-Chun Chu, Ph.D.

No abstract provided.

The Proto-Oncogene C-Kit Maps To Canid B-Chromosomes, Alexander S. Graphodatsky, Anna V. Kukekova, Dmitry V. Yudkin, Vladimir A. Trifonov, Nadezhda V. Vorobieva, Violetta R. Beklemisheva, Polina L. Perelman, Daria A. Graphodatskaya, Lyudmila N. Trut, Fengtang Yang, Malcolm A. Ferguson-Smith, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

Bioinformatic Analysis Of The Metal-Binding Protein Families And Heavy Metal Resistance Amongst Cyanobacteria, Tin-Chun Chu, Lee Lee, Shankar Srinivasan

Tin-Chun Chu, Ph.D.

No abstract provided.

Extremely Variable Di- And Tetranucleotide Microsatellite Loci In Brazilian Free-Tailed Bats (Tadarida Brasiliensis), Amy L. Russell, A. S. Turmelle, V. A. Brown, G. F. Mccracken

Amy L. Russell

Genetic Variation And Migration In The Mexican Free-Tailed Bat (Tadarida Brasiliensis Mexicana), Amy L. Russell, R. A. Medellín, G. F. Mccracken

Amy L. Russell

Plant Ontology (Po): A Controlled Vocabulary Of Plant Structures And Growth Stages, Pankaj Jaiswal, Shulamit Avraham, Katica Ilic, Elizabeth A. Kellogg, Susan Mccouch, Anuradha Pujar, Leonore Reiser, Seung Y. Rhee, Martin M. Sachs, Mary L. Schaeffer, Lincoln Stein, Peter Stevens, Leszek Vincent, Doreen Ware, Felipe Zapata

Peter Stevens

Poor Taxon Sampling, Poor Character Sampling, And Non-Repeatable Analyses Of A Contrived Dataset Do Not Provide A More Credible Estimate Of Insect Phylogeny: A Reply To Kjer., T. Heath Ogden

T. Heath Ogden

The wealth of data available for phylogenetic analysis of the insect orders, from both morphological and molecular sources, is steadily increasing. However, controversy exists among the methodologies one can use to reconstruct ordinal relationships. Recently, Kjer (2004) presented an analysis of insect ordinal relationships based exclusively on a single source of information: 18S rDNA sequence data. Kjer claims that his analysis resulted in a more ‘‘credible’’ phylogeny for the insect orders and strongly criticized our previous phylogenetic results. However, Kjer only used a subset of the data that are currently available for insect ordinal phylogeny, misrepresented our analyses, and omitted …

Phylogeny Of Ephemeroptera (Mayflies) Based On Molecular Evidence, T. Heath Ogden

T. Heath Ogden

This study represents the Wrst molecular phylogeny for the Order Ephemeroptera. The analyses included 31 of the 37 families, representing »24% of the genera. Fifteen families were supported as being monophyletic, Wve families were supported as nonmonophyletic, and 11 families were only represented by one species, and monophyly was not testable. The suborders Furcatergalia and Carapacea were supported as monophyletic while Setisura and Pisciforma were not supported as monophyletic. The superfamilies Ephemerelloidea and Caenoidea were supported as monophyletic while Baetoidea, Siphlonuroidea, Ephemeroidea, and Heptagenioidea were not. Baetidae was recovered as sister to the remaining clades. The mayXy gill to wing …