Open Access. Powered by Scholars. Published by Universities.®
- Keyword
Articles 1 - 14 of 14
Full-Text Articles in Life Sciences
Gene Expression Profiling Identifies The Zinc-Finger Protein Charlatan As A Regulator Of Intestinal Stem Cells In Drosophila, Alla Amcheslavsky, Yingchao Nie, Qi Li, Feng He, Michele Markstein, Yt Ip, Leo Tsuda
Gene Expression Profiling Identifies The Zinc-Finger Protein Charlatan As A Regulator Of Intestinal Stem Cells In Drosophila, Alla Amcheslavsky, Yingchao Nie, Qi Li, Feng He, Michele Markstein, Yt Ip, Leo Tsuda
Michele Markstein
Intestinal stem cells (ISCs) in the adult Drosophila midgut can respond to tissue damage and support repair. We used genetic manipulation to increase the number of ISC-like cells in the adult midgut and performed gene expression profiling to identify potential ISC regulators. A detailed analysis of one of these potential regulators, the zinc-finger protein Charlatan, was carried out. MARCM clonal analysis and RNAi in precursor cells showed that loss of Chn function caused severe ISC division defects, including loss of EdU incorporation, phosphorylated histone 3 staining and expression of the mitotic protein Cdc2. Loss of Charlatan also led to a …
Gene Number Determination And Genetic Polymorphism Of The Gamma Delta T Cell Co-Receptor Wc1 Genes, Chuang Chen, Carolyn Ta Herzig, Leeson J. Alexander, John W. Keele, Tara G. Mcdaneld, Janice C. Telfer, Cynthia L. Brown
Gene Number Determination And Genetic Polymorphism Of The Gamma Delta T Cell Co-Receptor Wc1 Genes, Chuang Chen, Carolyn Ta Herzig, Leeson J. Alexander, John W. Keele, Tara G. Mcdaneld, Janice C. Telfer, Cynthia L. Brown
Janice C. Telfer
Background: WC1 co-receptors belong to the scavenger receptor cysteine-rich (SRCR) superfamily and are encoded by a multi-gene family. Expression of particular WC1 genes defines functional subpopulations of WC1+ γδ T cells. We have previously identified partial or complete genomic sequences for thirteen different WC1 genes through annotation of the bovine genome Btau_3.1 build. We also identified two WC1 cDNA sequences from other cattle that did not correspond to sequences in the Btau_3.1 build. Their absence in the Btau_3.1 build may have reflected gaps in the genome assembly or polymorphisms among animals. Since the response of γδ T cells to bacterial …
Brachypodium As A Model For The Grasses: Today And The Future, Ana Lucia Caicedo, J. Brkljacic, E. Grotewold, R. Scholl, T. Mocker, D. F. Garvin, P. Vain, T. Brutnell, R. Sibout, M. Bevan, H. Budak, C. Gao, Y. Gu, S. P. Hazen, B. F. Holt Iii, S. -Y Hong, M. Jordan, A. J. Manzaneda, T. Michell-Olds, K. Mochida, L. A.J. Mur, C. -M. Park, J. Sedbrook, M. Watt, S. J. Zheng, J. P. Vogel
Brachypodium As A Model For The Grasses: Today And The Future, Ana Lucia Caicedo, J. Brkljacic, E. Grotewold, R. Scholl, T. Mocker, D. F. Garvin, P. Vain, T. Brutnell, R. Sibout, M. Bevan, H. Budak, C. Gao, Y. Gu, S. P. Hazen, B. F. Holt Iii, S. -Y Hong, M. Jordan, A. J. Manzaneda, T. Michell-Olds, K. Mochida, L. A.J. Mur, C. -M. Park, J. Sedbrook, M. Watt, S. J. Zheng, J. P. Vogel
Ana Lucia Caicedo
No abstract provided.
Molecular Evolution Of The Rice Blast Resistance Gene Pi-Ta In Invasive Weedy Rice In The Usa, Ana Lucia Caicedo, S. Lee, Y. Jia, D. R. Gealy, K. M. Olsen
Molecular Evolution Of The Rice Blast Resistance Gene Pi-Ta In Invasive Weedy Rice In The Usa, Ana Lucia Caicedo, S. Lee, Y. Jia, D. R. Gealy, K. M. Olsen
Ana Lucia Caicedo
The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and …
Timing Is Everything: Early Degradation Of Abscission Layer Is Associated With Increased Seed Shattering In U.S. Weedy Rice, Ana Lucia Caicedo, C. S. Thurber, P. K. Helper
Timing Is Everything: Early Degradation Of Abscission Layer Is Associated With Increased Seed Shattering In U.S. Weedy Rice, Ana Lucia Caicedo, C. S. Thurber, P. K. Helper
Ana Lucia Caicedo
Background Seed shattering, or shedding, is an important fitness trait for wild and weedy grasses. U.S. weedy rice (Oryza sativa) is a highly shattering weed, thought to have evolved from non-shattering cultivated ancestors. All U.S. weedy rice individuals examined to date contain a mutation in the sh4 locus associated with loss of shattering during rice domestication. Weedy individuals also share the shattering trait with wild rice, but not the ancestral shattering mutation at sh4; thus, how weedy rice reacquired the shattering phenotype is unknown. To establish the morphological basis of the parallel evolution of seed shattering in weedy rice and …
Genomic Patterns Of Nucleotide Diversity In Divergent Populations Of U.S. Weedy Rice, Michael Reagon, Carrie S. Thurber, Brian L. Gross, Kenneth M. Olsen, Yulin Jia, Ana Lucia Caicedo
Genomic Patterns Of Nucleotide Diversity In Divergent Populations Of U.S. Weedy Rice, Michael Reagon, Carrie S. Thurber, Brian L. Gross, Kenneth M. Olsen, Yulin Jia, Ana Lucia Caicedo
Ana Lucia Caicedo
Background: Weedy rice (red rice), a conspecific weed of cultivated rice (Oryza sativa L.), is a significant problem throughout the world and an emerging threat in regions where it was previously absent. Despite belonging to the same species complex as domesticated rice and its wild relatives, the evolutionary origins of weedy rice remain unclear. We use genome-wide patterns of single nucleotide polymorphism (SNP) variation in a broad geographic sample of weedy, domesticated, and wild Oryza samples to infer the origin and demographic processes influencing U.S. weedy rice evolution. Results: We find greater population structure than has been previously reported for …
Exploiting Position Effects And The Gypsy Retrovirus Insulator To Engineer Precisely Expressed Transgenes, Michele Markstein, Chrysoula Pitsouli, Christians Villalta, Susan E. Celniker, Norbert Perrimon
Exploiting Position Effects And The Gypsy Retrovirus Insulator To Engineer Precisely Expressed Transgenes, Michele Markstein, Chrysoula Pitsouli, Christians Villalta, Susan E. Celniker, Norbert Perrimon
Michele Markstein
A major obstacle to creating precisely expressed transgenes lies in the epigenetic effects of the host chromatin that surrounds them. Here we present a strategy to overcome this problem, employing a Gal4-inducible luciferase assay to systematically quantify position effects of host chromatin and the ability of insulators to counteract these effects at phiC31 integration loci randomly distributed throughout the Drosophila genome. We identify loci that can be exploited to deliver precise doses of transgene expression to specific tissues. Moreover, we uncover a previously unrecognized property of the gypsy retrovirus insulator to boost gene expression to levels severalfold greater than at …
Geographic Diversity Cline Of R Gene Homologs In Wild Populations Of Solanum Pimpinellifolium (Solanaceae), Ana Lucia Caicedo
Geographic Diversity Cline Of R Gene Homologs In Wild Populations Of Solanum Pimpinellifolium (Solanaceae), Ana Lucia Caicedo
Ana Lucia Caicedo
Plant resistance (R) genes tend to be highly variable within plant species and are thought to be under natural selection; however, little is known about the geographic distribution of R gene diversity within and among plant populations. To determine the possible roles of demography and selection on R gene evolution, patterns of diversity at the multigenic Cf-2 R gene family were studied in Solanum pimpinellifolium populations along the northern coast of Peru. Population diversity levels of Cf-2 homologs follow a latitudinal cline, consistent with the species's history of gradual colonization of the Peruvian coast and population variation in outcrossing levels. …
Genome-Wide Patterns Of Nucleotide Polymorphism In Domesticated Rice, Ana Lucia Caicedo, S. H. Williamson, R, D. Hernandez, A. Boyko, A. Fleded-Alon, T. L. York, N. Polato, K. M. Olsen, R. Nielsen, S. Mccouch, C. D. Bustamante, M. D. Purugganan
Genome-Wide Patterns Of Nucleotide Polymorphism In Domesticated Rice, Ana Lucia Caicedo, S. H. Williamson, R, D. Hernandez, A. Boyko, A. Fleded-Alon, T. L. York, N. Polato, K. M. Olsen, R. Nielsen, S. Mccouch, C. D. Bustamante, M. D. Purugganan
Ana Lucia Caicedo
Domesticated Asian rice (Oryza sativa) is one of the oldest domesticated crop species in the world, having fed more people than any other plant in human history. We report the patterns of DNA sequence variation in rice and its wild ancestor, O. rufipogon, across 111 randomly chosen gene fragments, and use these to infer the evolutionary dynamics that led to the origins of rice. There is a genome-wide excess of high-frequency derived single nucleotide polymorphisms (SNPs) in O. sativa varieties, a pattern that has not been reported for other crop species. We developed several alternative models to explain contemporary patterns …
Vernalization Sensitivity In Arabidopsis Thaliana (Brassicaceae): The Effects Of Latitude And Flc Variation, Ana Lucia Caicedo, M. D. Purugganan, C. Mays, R. Hopkins, J. R. Stinchcombe, J. Schmitt, J. R. Stichcombe
Vernalization Sensitivity In Arabidopsis Thaliana (Brassicaceae): The Effects Of Latitude And Flc Variation, Ana Lucia Caicedo, M. D. Purugganan, C. Mays, R. Hopkins, J. R. Stinchcombe, J. Schmitt, J. R. Stichcombe
Ana Lucia Caicedo
Latitudinal variation in climate is predicted to select for latitudinal differentiation in sensitivity to the environmental cues that signal plants to flower at the appropriate time for a given climate. In Arabidopsis thaliana, flowering is promoted by exposure to cold temperatures (vernalization), and several vernalization pathway loci are known. To test whether natural variation in vernalization sensitivity could account for a previously observed latitudinal cline in flowering time in A. thaliana, we exposed 21 European accessions to 0, 10, 20, or 30 d of vernalization and observed leaf number at flowering under short days in a growth chamber. We observed …
Comparative Plant Genomics. Frontiers And Prospects, Ana Lucia Caicedo, M. D. Purugganan
Comparative Plant Genomics. Frontiers And Prospects, Ana Lucia Caicedo, M. D. Purugganan
Ana Lucia Caicedo
No abstract provided.
Heterogeneous Evolutionary Processes Affect R Gene Diversity In Natural Populations Of Solanum Pimpinellifolium, Ana Lucia Caicedo, B. A. Schaal
Heterogeneous Evolutionary Processes Affect R Gene Diversity In Natural Populations Of Solanum Pimpinellifolium, Ana Lucia Caicedo, B. A. Schaal
Ana Lucia Caicedo
Resistance (R) genes of plants are responsible for pathogen recognition and encode proteins that trigger a cascade of responses when a pathogen invades a plant. R genes are assumed to be under strong selection, but there is limited knowledge of the processes affecting R gene diversity in the wild. In this study, DNA sequence variation of Cf-2 homologs was surveyed in populations of Solanum pimpinellifolium, a wild relative of the cultivated tomato. The Cf-2 locus is involved in resistance to strains of the fungus Cladosporium fulvum. At least 26 different Cf-2 homologs were detected in natural populations of S. pimpinellifolium. …
Epistatic Interaction Between The Arabidopsis Fri And Flc Flowering Time Genes Generates A Latitudinal Cline In A Life History Trait, Ana Lucia Caicedo, J. R. Stinchcombe, K. M. Olsen, J Schmitt, M. D. Purugganan
Epistatic Interaction Between The Arabidopsis Fri And Flc Flowering Time Genes Generates A Latitudinal Cline In A Life History Trait, Ana Lucia Caicedo, J. R. Stinchcombe, K. M. Olsen, J Schmitt, M. D. Purugganan
Ana Lucia Caicedo
Epistatic gene interactions are believed to be a major factor in the genetic architecture of evolutionary diversification. In Arabidopsis thaliana, the FRI and FLC genes mechanistically interact to control flowering time, and here we show that this epistatic interaction also contributes to a latitudinal cline in this life history trait within the species. Two major FLC haplogroups (FLCA and FLCB ) are associated with flowering time variation in A. thaliana in field conditions, but only in the presence of putatively functional FRI alleles. Significant differences in latitudinal distribution of FLC haplogroups in Eurasia and North Africa also depend on the …
Diversity And Molecular Evolution Of The Rps2 Resistance Gene In Arabidopsis Thaliana, Ana Lucia Caicedo
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, …