scholarly journals cis-regulatory sequences responsible for alternative splicing of the Drosophila dopa decarboxylase gene.

1994 ◽  
Vol 14 (11) ◽  
pp. 7385-7393 ◽  
Author(s):  
J Shen ◽  
J Hirsh
Keyword(s):  
Alternative Splicing ◽  
Germ Line ◽  
Fusion Gene ◽  
P Element ◽  
Dopa Decarboxylase ◽  
Regulatory Sequences ◽  
Exon 1 ◽  
Alternatively Spliced ◽  
The Central Nervous System ◽  
Germ Line Transformation

The Drosophila dopa decarboxylase gene, Ddc, is expressed in the hypoderm and in specific sets of cells in the central nervous system (CNS). The unique Ddc primary transcript is alternatively spliced in these two tissues. The Ddc CNS mRNA contains all four exons (A through D), whereas the hypodermal mRNA contains only three exons (A, C, and D). To localize cis-regulatory sequences responsible for Ddc alternative splicing, a Ddc minigene and several fusion genes containing various amounts of Ddc sequences fused to fushi tarazu (ftz) exon 1 were constructed and introduced into flies by P-element-mediated germ line transformation. We find that Ddc intron ab and exon B are sufficient to regulate Ddc alternative splicing, since transcripts of a minimal fusion gene containing most of Ddc intron ab and exon B are spliced to exon B in the CNS but not in the hypoderm. These results indicate that Ddc alternative splicing is regulated by either a negative mechanism preventing splicing to exon B in the hypoderm or a positive mechanism activating splicing to exon B in the CNS. Our previous data suggest that Ddc hypodermal splicing is the actively regulated splicing pathway (J. Shen, C. J. Beall, and J. Hirsh, Mol. Cell. Biol. 13:4549-4555, 1993). Here we show that deletion of Ddc intron ab sequences selectively disrupts hypodermal splicing specificity. These results support a model in which Ddc alternative splicing is negatively regulated by a blockage mechanism preventing splicing to exon B in the hypoderm.

cis-regulatory sequences responsible for alternative splicing of the Drosophila dopa decarboxylase gene

1994 ◽  
Vol 14 (11) ◽  
pp. 7385-7393
Author(s):  
J Shen ◽  
J Hirsh
Keyword(s):  
Alternative Splicing ◽  
Germ Line ◽  
Fusion Gene ◽  
P Element ◽  
Dopa Decarboxylase ◽  
Regulatory Sequences ◽  
Exon 1 ◽  
Alternatively Spliced ◽  
The Central Nervous System ◽  
Germ Line Transformation

The Drosophila dopa decarboxylase gene, Ddc, is expressed in the hypoderm and in specific sets of cells in the central nervous system (CNS). The unique Ddc primary transcript is alternatively spliced in these two tissues. The Ddc CNS mRNA contains all four exons (A through D), whereas the hypodermal mRNA contains only three exons (A, C, and D). To localize cis-regulatory sequences responsible for Ddc alternative splicing, a Ddc minigene and several fusion genes containing various amounts of Ddc sequences fused to fushi tarazu (ftz) exon 1 were constructed and introduced into flies by P-element-mediated germ line transformation. We find that Ddc intron ab and exon B are sufficient to regulate Ddc alternative splicing, since transcripts of a minimal fusion gene containing most of Ddc intron ab and exon B are spliced to exon B in the CNS but not in the hypoderm. These results indicate that Ddc alternative splicing is regulated by either a negative mechanism preventing splicing to exon B in the hypoderm or a positive mechanism activating splicing to exon B in the CNS. Our previous data suggest that Ddc hypodermal splicing is the actively regulated splicing pathway (J. Shen, C. J. Beall, and J. Hirsh, Mol. Cell. Biol. 13:4549-4555, 1993). Here we show that deletion of Ddc intron ab sequences selectively disrupts hypodermal splicing specificity. These results support a model in which Ddc alternative splicing is negatively regulated by a blockage mechanism preventing splicing to exon B in the hypoderm.

scholarly journals Trans-acting Factors Required for Inclusion of Regulated Exons in the Ultrabithorax mRNAs of Drosophila melanogaster

Genetics ◽  
1999 ◽  
Vol 151 (4) ◽  
pp. 1517-1529 ◽  
Author(s):  
James M Burnette ◽  
Allyson R Hatton ◽  
A Javier Lopez
Keyword(s):  
Drosophila Melanogaster ◽  
Alternative Splicing ◽  
P Element ◽  
Splicing Factors ◽  
Loss Of Function ◽  
Large Collection ◽  
Splicing Pattern ◽  
Alternatively Spliced ◽  
Hypomorphic Alleles

Abstract Alternatively spliced Ultrabithorax mRNAs differ by the presence of internal exons mI and mII. Two approaches were used to identify trans-acting factors required for inclusion of these cassette exons. First, mutations in a set of genes implicated in the control of other alternative splicing decisions were tested for dominant effects on the Ubx alternative splicing pattern. To identify additional genes involved in regulation of Ubx splicing, a large collection of deficiencies was tested first for dominant enhancement of the haploinsufficient Ubx haltere phenotype and second for effects on the splicing pattern. Inclusion of the cassette exons in Ubx mRNAs was reduced strongly in heterozygotes for hypomorphic alleles of hrp48, which encodes a member of the hnRNP A/B family and is implicated in control of P-element splicing. Significant reductions of mI and mII inclusion were also observed in heterozygotes for loss-of-function alleles of virilizer, fl(2)d, and crooked neck. The products of virilizer and fl(2)d are also required for Sxl autoregulation at the level of splicing; crooked neck encodes a protein with structural similarities to yeast-splicing factors Prp39p and Prp42p. Deletion of at least five other loci caused significant reductions in the inclusion of mI and/or mII. Possible roles of identified factors are discussed in the context of the resplicing strategy for generation of alternative Ubx mRNAs.

Delimiting regulatory sequences of the Drosophila melanogaster Ddc gene

1986 ◽  
Vol 6 (12) ◽  
pp. 4548-4557
Author(s):  
J Hirsh ◽  
B A Morgan ◽  
S B Scholnick
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Regulatory Elements ◽  
P Element ◽  
Developmental Expression ◽  
Upstream Region ◽  
Regulatory Sequences ◽  
Flanking Sequences

We delimited sequences necessary for in vivo expression of the Drosophila melanogaster dopa decarboxylase gene Ddc. The expression of in vitro-altered genes was assayed following germ line integration via P-element vectors. Sequences between -209 and -24 were necessary for normally regulated expression, although genes lacking these sequences could be expressed at 10 to 50% of wild-type levels at specific developmental times. These genes showed components of normal developmental expression, which suggests that they retain some regulatory elements. All Ddc genes lacking the normal immediate 5'-flanking sequences were grossly deficient in larval central nervous system expression. Thus, this upstream region must contain at least one element necessary for this expression. A mutated Ddc gene without a normal TATA boxlike sequence used the normal RNA start points, indicating that this sequences is not required for start point specificity.

P-element-mediated enhancer detection applied to the study of oogenesis in Drosophila

Development ◽  
1989 ◽  
Vol 107 (2) ◽  
pp. 189-200 ◽  
Author(s):  
U. Grossniklaus ◽  
H.J. Bellen ◽  
C. Wilson ◽  
W.J. Gehring
Keyword(s):  
Germ Line ◽  
Expression Patterns ◽  
Cell Types ◽  
Regulatory Elements ◽  
P Element ◽  
Regulatory Sequences ◽  
Transcriptional Regulatory ◽  
Morphological Criteria ◽  
Enhancer Detection ◽  
New Strategies

We have stained the ovaries of nearly 600 different Drosophila strains carrying single copies of a P-element enhancer detector. This transposon detects neighbouring genomic transcriptional regulatory sequences by means of a beta-galactosidase reporter gene. Numerous strains are stained in specific cells and at specific stages of oogenesis and provide useful ovarian markers for cell types that in some cases have not previously been recognized by morphological criteria. Since recent data have suggested that a substantial number of the regulatory elements detected by enhancer detection control neighbouring genes, we discuss the implications of our results concerning ovarian gene expression patterns in Drosophila. We have also identified a small number of insertion-linked recessive mutants that are sterile or lead to ovarian defects. We observe a strong correlation with specific germ line staining patterns in these strains, suggesting that certain patterns are more likely to be associated with female sterile genes than others. On the basis of our results, we suggest new strategies, which are not primarily based on the generation of mutants, to screen for and isolated female sterile genes.

scholarly journals P transposons controlled by the heat shock promoter.

1986 ◽  
Vol 6 (5) ◽  
pp. 1640-1649 ◽  
Author(s):  
H Steller ◽  
V Pirrotta
Keyword(s):  
Heat Shock ◽  
Germ Line ◽  
Fusion Gene ◽  
P Element ◽  
Translational Efficiency ◽  
Heat Shock Promoter ◽  
P Elements ◽  
Heat Shocks ◽  
Neomycin Resistance ◽  
Heat Shock Induction

We have transformed Drosophila melanogaster with modified P-element transposons, which express the transposase function from the heat-inducible hsp70 heat shock promoter. The Icarus transposon, which contains a direct hsp70-P fusion gene, behaved like a very active autonomous P element even before heat shock induction. Although heat shock led to abundant somatic transcription, transposition of the Icarus element was confined to germ line cells. To reduce the constitutive transposase activity observed for the Icarus element, we attenuated the translational efficiency of the transposase RNA by inserting the transposon 5 neomycin resistance gene between the hsp70 promoter and the P-element sequences. The resulting construct, called Icarus-neo, conferred resistance to G418, and its transposition was significantly stimulated by heat shock. Heat shocks applied during the embryonic or third instar larval stage had similar effects, indicating that transposition of P elements is not restricted to a certain developmental stage. Both Icarus and Icarus-neo destabilized snw in a P-cytotype background and thus at least partially overcome the repression of transposition. Our results suggest that the regulation of P-element transposition occurs at both the transcriptional and posttranscriptional levels.

Plasma-membrane calcium pumps and hereditary deafness

2007 ◽  
Vol 35 (5) ◽  
pp. 913-918 ◽  
Author(s):  
M. Brini ◽  
F. Di Leva ◽  
T. Domi ◽  
L. Fedrizzi ◽  
D. Lim ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Plasma Membrane ◽  
Alternative Splicing ◽  
Membrane Domains ◽  
Hereditary Deafness ◽  
Calcium Pumps ◽  
Specific Targeting ◽  
Alternatively Spliced ◽  
The Central Nervous System

In mammals, four different genes encode four PMCA (plasma-membrane Ca2+-ATPase) isoforms. PMCA1 and 4 are expressed ubiquitously, and PMCA2 and 3 are expressed predominantly in the central nervous system. More than 30 variants are generated by mechanisms of alternative splicing. The physiological meaning of the existence of so many isoforms is not clear, but evidently it must be related to the cell-specific demands of Ca2+ homoeostasis. Recent studies suggest that the alternatively spliced regions in PMCA are responsible for specific targeting to plasma membrane domains, and proteins that bind specifically to the pumps could contribute to further regulation of Ca2+ control. In addition, the combination of proteins obtained by alternative splicing occurring at two different sites could be responsible for different functional characteristics of the pumps.

scholarly journals Myosin light-chain 1/3 gene alternative splicing: cis regulation is based upon a hierarchical compatibility between splice sites.

1990 ◽  
Vol 10 (5) ◽  
pp. 2133-2144 ◽  
Author(s):  
M E Gallego ◽  
B Nadal-Ginard
Keyword(s):  
Alternative Splicing ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Cooperative Interaction ◽  
Splice Sites ◽  
Exon 2 ◽  
Exon 1 ◽  
Alternatively Spliced ◽  
Flanking Sequences ◽  
Exon 4

The mechanisms involved in the selective joining of appropriate 5' and 3' splice sites are still poorly understood in both constitutive and alternatively spliced genes. With two promoters associated with different exons, the myosin light-chain 1/3 gene generates two pre-mRNAs that also differ by the use of a pair of internal exons, 3 and 4, that are spliced in a mutually exclusive fashion. When the promoter upstream from exon 1 is used, only exon 4 is included. If the promoter upstream from exon 2 is used, only exon 3 is included. In an attempt to understand the molecular basis for the mutually exclusive behavior of these two exons and the basis of their specific selection, a number of minigene constructs containing exons 3 and 4 were tested in a variety of homologous or heterologous cis and trans environments. The results demonstrate that the mutually exclusive behavior of myosin light-chain exons 3 and 4 and selection between the two exons are cis regulated and are affected by the nature of the flanking sequences. Both exons competed for the common flanking 5' and 3' splice sites. Flanking exons were found that favored inclusion into mature mRNA of exon 3, exon 4, both, or neither, suggesting a specific cooperative interaction between certain 5' and 3' splice sites. Thus, alternative splicing of myosin light-chain 1/3 pre-mRNAs is regulated in cis by a hierarchy of compatibilities between pairs of 5' and 3' splice sites.

scholarly journals Repression and activation of the Drosophila dopa decarboxylase gene in glia.

1992 ◽  
Vol 12 (12) ◽  
pp. 5659-5666 ◽  
Author(s):  
G S Mastick ◽  
S B Scholnick
Keyword(s):  
Germ Line ◽  
Transcriptional Start Site ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Dopa Decarboxylase ◽  
In Vitro Mutagenesis ◽  
Wild Type ◽  
Cell Activator ◽  
Germ Line Transformation

Glial expression of the Drosophila dopa decarboxylase gene (Ddc) is repressed by a regulatory region located approximately 1 kb upstream of the transcriptional start site. We have used in vitro mutagenesis and germ line transformation to determine which elements within the Ddc promoter mediate repression. Our evidence suggests that the hypodermal cell activator elements IIA and IIB play a major role in the transcriptional regulation of Ddc in glial cells. A variety of mutations demonstrate that element IIA is a strong glial activator element and that element IIB is necessary for glial repression. Although these two regulatory elements are nearly identical in sequence, our data suggest that they are not redundant. Altering the wild-type number and spacing of elements IIA and IIB indicates that the wild-type arrangement of this repeat is critical for repression. We conclude that these key elements of the Ddc promoter regulate both activation and repression in glia.

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