scholarly journals Conversion of lacZ Enhancer Trap Lines to GAL4 Lines Using Targeted Transposition in Drosophila melanogaster

Genetics ◽  
1999 ◽  
Vol 151 (3) ◽  
pp. 1093-1101 ◽  
Author(s):  
Katharine J Sepp ◽  
Vanessa J Auld
Keyword(s):  
Expression System ◽  
Enhancer Trap ◽  
P Element ◽  
Specific Expression ◽  
Complete Replacement ◽  
New Genes ◽  
Biological Studies ◽  
Gal4 Expression ◽  
Element Mobilization ◽  
Low Efficiency

Abstract Since the development of the enhancer trap technique, many large libraries of nuclear localized lacZ P-element stocks have been generated. These lines can lend themselves to the molecular and biological characterization of new genes. However they are not as useful for the study of development of cellular morphologies. With the advent of the GAL4 expression system, enhancer traps have a far greater potential for utility in biological studies. Yet generation of GAL4 lines by standard random mobilization has been reported to have a low efficiency. To avoid this problem we have employed targeted transposition to generate glial-specific GAL4 lines for the study of glial cellular development. Targeted transposition is the precise exchange of one P element for another. We report the successful and complete replacement of two glial enhancer trap P[lacZ, ry+] elements with the P[GAL4, w+] element. The frequencies of transposition to the target loci were 1.3% and 0.4%. We have thus found it more efficient to generate GAL4 lines from preexisting P-element lines than to obtain tissue-specific expression of GAL4 by random P-element mobilization. It is likely that similar screens can be performed to convert many other P-element lines to the GAL4 system.

Non-Viral Vectors for Gene Delivery

2018 ◽  
Vol 9 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Aparna Bansal ◽  
Himanshu
Keyword(s):  
Gene Therapy ◽  
Viral Vectors ◽  
Transfection Efficiency ◽  
Gene Transfection ◽  
Expression System ◽  
Target Cells ◽  
Specific Expression ◽  
Naked Dna

Introduction: Gene therapy has emerged out as a promising therapeutic pave for the treatment of genetic and acquired diseases. Gene transfection into target cells using naked DNA is a simple and safe approach which has been further improved by combining vectors or gene carriers. Both viral and non-viral approaches have achieved a milestone to establish this technique, but non-viral approaches have attained a significant attention because of their favourable properties like less immunotoxicity and biosafety, easy to produce with versatile surface modifications, etc. Literature is rich in evidences which revealed that undoubtedly, non–viral vectors have acquired a unique place in gene therapy but still there are number of challenges which are to be overcome to increase their effectiveness and prove them ideal gene vectors. Conclusion: To date, tissue specific expression, long lasting gene expression system, enhanced gene transfection efficiency has been achieved with improvement in delivery methods using non-viral vectors. This review mainly summarizes the various physical and chemical methods for gene transfer in vitro and in vivo.

scholarly journals hobo enhancer trapping mutagenesis in Drosophila reveals an insertion specificity different from P elements.

Genetics ◽  
1993 ◽  
Vol 135 (4) ◽  
pp. 1063-1076 ◽  
Author(s):  
D Smith ◽  
J Wohlgemuth ◽  
B R Calvi ◽  
I Franklin ◽  
W M Gelbart
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Element ◽  
Enhancer Trap ◽  
P Element ◽  
Present Evidence ◽  
P Elements ◽  
Element Insertion ◽  
Enhancer Trapping ◽  
Indispensable Tool

Abstract P element enhancer trapping has become an indispensable tool in the analysis of the Drosophila melanogaster genome. However, there is great variation in the mutability of loci by these elements such that some loci are relatively refractory to insertion. We have developed the hobo transposable element for use in enhancer trapping and we describe the results of a hobo enhancer trap screen. In addition, we present evidence that a hobo enhancer trap element has a pattern of insertion into the genome that is different from the distribution of P elements in the available database. Hence, hobo insertion may facilitate access to genes resistant to P element insertion.

Genes Expressed in the Ring Gland, the Major Endocrine Organ of Drosophila melanogaster

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 217-231
Author(s):  
Peter D Harvie ◽  
Maria Filippova ◽  
Peter J Bryant
Keyword(s):  
Reporter Gene ◽  
Translational Regulation ◽  
Developmental Stages ◽  
System Development ◽  
Elongation Factor ◽  
Endocrine System ◽  
Nervous System Development ◽  
Enhancer Trap ◽  
P Element ◽  
Ring Gland

Abstract We have used an enhancer-trap approach to begin characterizing the function of the Drosophila endocrine system during larval development. Five hundred and ten different lethal PZ element insertions were screened to identify those in which a reporter gene within the P element showed strong expression in part or all of the ring gland, the major site of production and release of developmental hormones, and which had a mutant phenotype consistent with an endocrine defect. Nine strong candidate genes were identified in this screen, and eight of these are expressed in the lateral cells of the ring gland that produce ecdysteroid molting hormone (EC). We have confirmed that the genes detected by these enhancer traps are expressed in patterns similar to those detected by the reporter gene. Two of the genes encode proteins, protein kinase A and calmodulin, that have previously been implicated in the signaling pathway leading to EC synthesis and release in other insects. A third gene product, the translational elongation factor EF-1α F1, could play a role in the translational regulation of EC production. The screen also identified the genes couch potato and tramtrack, previously known from their roles in peripheral nervous system development, as being expressed in the ring gland. One enhancer trap revealed expression of the gene encoding the C subunit of vacuolar ATPase (V-ATPase) in the medial cells of the ring gland, which produce the juvenile hormone that controls progression through developmental stages. This could reveal a function of V-ATPase in the response of this part of the ring gland to adenotropic neuropeptides. However, the gene identified by this enhancer trap is ubiquitously expressed, suggesting that the enhancer trap is detecting only a subset of its control elements. The results show that the enhancer trap approach can be a productive way of exploring tissue-specific genetic functions in Drosophila.

Identification of Chromosome Inheritance Modifiers in Drosophila melanogaster

Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1623-1637 ◽  
Author(s):  
Kenneth W Dobie ◽  
Cameron D Kennedy ◽  
Vivienne M Velasco ◽  
Tory L McGrath ◽  
Juliani Weko ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Biological Activity ◽  
Cancer Progression ◽  
Birth Defects ◽  
Mitotic Chromosome ◽  
P Element ◽  
Inverse Pcr ◽  
Gtpase Activating Protein ◽  
New Genes ◽  
Genomic Analyses

Abstract Faithful chromosome inheritance is a fundamental biological activity and errors contribute to birth defects and cancer progression. We have performed a P-element screen in Drosophila melanogaster with the aim of identifying novel candidate genes involved in inheritance. We used a “sensitized” minichromosome substrate (J21A) to screen ∼3,000 new P-element lines for dominant effects on chromosome inheritance and recovered 78 Sensitized chromosome inheritance modifiers (Scim). Of these, 69 decreased minichromosome inheritance while 9 increased minichromosome inheritance. Fourteen mutations are lethal or semilethal when homozygous and all exhibit dramatic mitotic defects. Inverse PCR combined with genomic analyses identified P insertions within or close to genes with previously described inheritance functions, including wings apart-like (wapl), centrosomin (cnn), and pavarotti (pav). Further, lethal insertions in replication factor complex 4 (rfc4) and GTPase-activating protein 1 (Gap1) exhibit specific mitotic chromosome defects, discovering previously unknown roles for these proteins in chromosome inheritance. The majority of the lines represent mutations in previously uncharacterized loci, many of which have human homologs, and we anticipate that this collection will provide a rich source of mutations in new genes required for chromosome inheritance in metazoans.

scholarly journals An Enhancer Trap Screen for Ecdysone-Inducible Genes Required for Drosophila Adult Leg Morphogenesis

Genetics ◽  
2000 ◽  
Vol 156 (4) ◽  
pp. 1765-1776 ◽  
Author(s):  
Julie Gates ◽  
Carl S Thummel
Keyword(s):  
Hormonal Regulation ◽  
Sequence Similarity ◽  
Enhancer Trap ◽  
P Element ◽  
Lacz Reporter Gene ◽  
Hnrnp K ◽  
Leg Development ◽  
Drosophila Homolog ◽  
New Directions ◽  
Inducible Genes

Abstract Although extensive studies of Drosophila imaginal disc development have focused on proliferation and patterning, relatively little is known about how the patterned imaginal discs are transformed into adult structures during metamorphosis. Studies focused primarily on leg development have shown that this remarkable transformation is coordinated by pulses of the steroid hormone ecdysone and requires the function of ecdysone-inducible transcription factors as well as proteases and components of the contractile cytoskeleton and adherens junctions. Here, we describe a genetic screen aimed at expanding our understanding of the hormonal regulation of Drosophila adult leg morphogenesis. We screened 1300 lethal P-element enhancer trap insertions on the second chromosome for a series of sequential parameters including pupal lethality, defects in leg morphogenesis, and ecdysone-induced lacZ reporter gene expression. From this screen we identified four mutations, one of which corresponds to bancal, which encodes the Drosophila homolog of hnRNP K. We also identified vulcan, which encodes a protein that shares sequence similarity with a family of rat SAPAP proteins. Both bancal and vulcan are inducible by ecdysone, thus linking the hormone signal with leg morphogenesis. This screen provides new directions for understanding the hormonal regulation of leg development during Drosophila metamorphosis.

Generation and early differentiation of glial cells in the first optic ganglion of Drosophila melanogaster

Development ◽  
1992 ◽  
Vol 115 (4) ◽  
pp. 903-911 ◽  
Author(s):  
M.L. Winberg ◽  
S.E. Perez ◽  
H. Steller
Keyword(s):  
Drosophila Melanogaster ◽  
Glial Cells ◽  
Enhancer Trap ◽  
P Element ◽  
Cell Divisions ◽  
Genetic Mosaic ◽  
First Optic Ganglion ◽  
Optic Ganglion ◽  
Glial Lineage ◽  
Enhancer Trap Lines

We have examined the generation and development of glial cells in the first optic ganglion, the lamina, of Drosophila melanogaster. Previous work has shown that the growth of retinal axons into the developing optic lobes induces the terminal cell divisions that generate the lamina monopolar neurons. We investigated whether photoreceptor ingrowth also influences the development of lamina glial cells, using P element enhancer trap lines, genetic mosaics and birthdating analysis. Enhancer trap lines that mark the differentiating lamina glial cells were found to require retinal innervation for expression. In mutants with only a few photoreceptors, only the few glial cells near ingrowing axons expressed the marker. Genetic mosaic analysis indicates that the lamina neurons and glial cells are readily separable, suggesting that these are derived from distinct lineages. Additionally, BrdU pulse-chase experiments showed that the cell divisions that produce lamina glia, unlike those producing lamina neurons, are not spatially or temporally correlated with the retinal axon ingrowth. Finally, in mutants lacking photoreceptors, cell divisions in the glial lineage appeared normal. We conclude that the lamina glial cells derive from a lineage that is distinct from that of the L-neurons, that glia are generated independently of photoreceptor input, and that completion of the terminal glial differentiation program depends, directly or indirectly, on an inductive signal from photoreceptor axons.

Mutations affecting the cytoskeletal organization of syncytial Drosophila embryos

Development ◽  
1993 ◽  
Vol 118 (4) ◽  
pp. 1245-1254 ◽  
Author(s):  
W. Sullivan ◽  
P. Fogarty ◽  
W. Theurkauf
Keyword(s):  
Mitotic Division ◽  
P Element ◽  
Drosophila Embryo ◽  
Nuclear Movement ◽  
Microtubule Organization ◽  
Cytoskeletal Organization ◽  
New Genes ◽  
Movement Organization ◽  
Cytoplasmic Organization ◽  
Drosophila Embryos

Cytoplasmic organization, nuclear migration, and nuclear division in the early syncytial Drosophila embryo are all modulated by the cytoskeleton. In an attempt to identify genes involved in cytoskeletal functions, we have examined a collection of maternal-effect lethal mutations induced by single P-element transposition for those that cause defects in nuclear movement, organization, or morphology during the syncytial embryonic divisions. We describe three mutations, grapes, scrambled, and nuclear-fallout, which define three previously uncharacterized genes. Females homozygous for these mutations produce embryos that exhibit extensive mitotic division errors only after the nuclei migrate to the surface. Analysis of the microfilament and microtubule organization in embryos derived from these newly identified mutations reveal disruptions in the cortical cytoskeleton. Each of the three mutations disrupts the actin-based pseudocleavage furrows and the cellularization furrows in a distinct fashion. In addition to identifying new genes involved in cytoskeletal organization, these mutations provide insights into cytoskeletal function during early Drosophila embryogenesis.

scholarly journals Presyncodon, a Web Server for Gene Design with the Evolutionary Information of the Expression Hosts

2018 ◽  
Vol 19 (12) ◽  
pp. 3872 ◽  
Author(s):  
Jian Tian ◽  
Qingbin Li ◽  
Xiaoyu Chu ◽  
Ningfeng Wu
Keyword(s):  
High Frequency ◽  
Synonymous Codon ◽  
Low Frequency ◽  
Synonymous Codon Usage ◽  
Codon Usage Pattern ◽  
Evolutionary Information ◽  
Specific Expression ◽  
Synonymous Codons ◽  
New Genes ◽  
And Function

In the natural host, most of the synonymous codons of a gene have been evolutionarily selected and related to protein expression and function. However, for the design of a new gene, most of the existing codon optimization tools select the high-frequency-usage codons and neglect the contribution of the low-frequency-usage codons (rare codons) to the expression of the target gene in the host. In this study, we developed the method Presyncodon, available in a web version, to predict the gene code from a protein sequence, using built-in evolutionary information on a specific expression host. The synonymous codon-usage pattern of a peptide was studied from three genomic datasets (Escherichia coli, Bacillus subtilis, and Saccharomyces cerevisiae). Machine-learning models were constructed to predict a selection of synonymous codons (low- or high-frequency-usage codon) in a gene. This method could be easily and efficiently used to design new genes from protein sequences for optimal expression in three expression hosts (E. coli, B. subtilis, and S. cerevisiae). Presyncodon is free to academic and noncommercial users; accessible at http://www.mobioinfor.cn/presyncodon_www/index.html.

scholarly journals A Comparison of Murine and Human Factor XI

Blood ◽  
1997 ◽  
Vol 90 (3) ◽  
pp. 1055-1064 ◽  
Author(s):  
David Gailani ◽  
Mao-Fu Sun ◽  
Yuehui Sun
Keyword(s):  
Messenger Rna ◽  
Human Factor ◽  
Dextran Sulfate ◽  
Specific Activity ◽  
Expression System ◽  
Contact Activation ◽  
Factor Xi ◽  
Specific Expression ◽  
Factor Xi Deficiency ◽  
Mammalian Expression

Factor XI is a plasma glycoprotein that is required for contact activation initiated fibrin formation in vitro and for normal hemostasis in vivo. In preparation for developing a mouse model of factor XI deficiency to facilitate investigations into this protease's contributions to coagulation, we cloned the complementary DNA for murine factor XI, expressed the protein in a mammalian expression system, and compared its properties with human recombinant factor XI. The 2.8-kb murine cDNA codes for a protein of 624 amino acids with 78% homology to human factor XI. Both recombinant murine and human factor XI are 160 kD homodimers comprised of two 80 kD polypeptides connected by disulfide bonds. Murine factor XI shortens the clotting time of human factor XI deficient plasma in an activated partial thromboplastin time assay, with a specific activity 50% to 70% that of the human protein. In a purified system, murine factor XI is activated by human factor XIIa and thrombin in the presence of dextran sulfate. Murine factor XI differs from human factor XI in that it undergoes autoactivation slowly in the presence of dextran sulfate. This is due primarily to murine factor XIa preferentially cleaving a site on zymogen factor XI within the light chain, rather than the activation site between Arg371 and Val372. Northern blots of polyadenylated messenger RNA show that murine factor XI message is expressed, as expected, primarily in the liver. In contrast, messenger RNA for human factor XI was identified in liver, pancreas, and kidney. The studies show that murine and human factor XI have similar structural and enzymatic properties. However, there may be variations in tissue specific expression and subtle differences in enzyme activity across species.

scholarly journals Development of cDNA normalization system and preliminary transcription analysis of KCS genes in apple tissues

2011 ◽  
Vol 59 (3) ◽  
pp. 9-12 ◽  
Author(s):  
Zsolt Albert ◽  
Cs. Deák ◽  
A. Miskó ◽  
M. Tóth ◽  
I. Papp
Keyword(s):  
Gene Expression ◽  
Expression System ◽  
Expression Patterns ◽  
Housekeeping Genes ◽  
Apple Fruit ◽  
Rt Pcr ◽  
Specific Primers ◽  
Specific Expression ◽  
Transcription Analysis ◽  
Tissue Specific

Wax production is an important aspect of apple (Malus domestica Borkh.) fruit development from both theoretical and practical point of views. The complex molecular mechanism that controls wax biosynthesis is still widely unknown but many studies focused on this topic. We aimed to develop further the experimental framework of these efforts with a description of an improved reference genes expression system. Results in the literature show that similarities exist among the expression of some housekeeping genes of different plant species. Based on these considerations and on gene expression data from Arabidopsis thaliana, some genes in apple were assigned for analysis. EST sequences of apple were used to design specific primers for RT-PCR experiments. Isolation of intact RNA from different apple tissues and performing RT-PCR reaction were also key point in obtaining expression patterns. To monitor DNA contamination of the RNA samples, specific primers were used that amplify intron-containing sequences from the cDNA. We found that actin primers can be used for the detection of intron containing genomic DNA, and tubulin primers are good internal controls in RT-PCR experiments. We were able to make a difference between tissue-specific and tissue-independent gene-expression, furthermore we found tissue specific differences between the expression patterns of candidate genes, that are potentially involved in wax-biosynthesis. Our results show that KCS1 and KCS4 are overexpressed in the skin tissue, this could mean that these genes have skin-specific expression in apple fruit.

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