scholarly journals Abnormal muscle development in the heldup3 mutant of Drosophila melanogaster is caused by a splicing defect affecting selected troponin I isoforms.

1993 ◽  
Vol 13 (3) ◽  
pp. 1433-1439 ◽  
Author(s):  
J A Barbas ◽  
J Galceran ◽  
L Torroja ◽  
A Prado ◽  
A Ferrús
Keyword(s):  
Drosophila Melanogaster ◽  
Splice Site ◽  
Muscle Development ◽  
Troponin I ◽  
Differential Splicing ◽  
Thin Filaments ◽  
Molecular Changes ◽  
Splicing Defect ◽  
Visible Effect ◽  
Thoracic Muscles

The troponin I (TnI) gene of Drosophila melanogaster encodes a family of 10 isoforms resulting from the differential splicing of 13 exons. Four of these exons (6a1, 6a2, 6b1, and 6b2) are mutually exclusive and very similar in sequence. TnI isoforms show qualitative specificity whereby each muscle expresses a selected repertoire of them. In addition, TnI isoforms show quantitative specificity whereby each muscle expresses characteristic amounts of each isoform. In the mutant heldup3, the development of the thoracic muscles DLM, DVM, and TDT is aborted. The mutation consists of a one-nucleotide displacement of the 3' AG splice site at the intron preceding exon 6b1, resulting in the failure to produce all exon 6b1-containing TnI isoforms. These molecular changes in a constituent of the thin filaments cause the selective failure to develop the DLM, DVM, and TDT muscles while having no visible effect on other muscles wherein exon 6b1 expression is minor.

Abnormal muscle development in the heldup3 mutant of Drosophila melanogaster is caused by a splicing defect affecting selected troponin I isoforms

1993 ◽  
Vol 13 (3) ◽  
pp. 1433-1439
Author(s):  
J A Barbas ◽  
J Galceran ◽  
L Torroja ◽  
A Prado ◽  
A Ferrús
Keyword(s):  
Drosophila Melanogaster ◽  
Splice Site ◽  
Muscle Development ◽  
Troponin I ◽  
Differential Splicing ◽  
Thin Filaments ◽  
Molecular Changes ◽  
Splicing Defect ◽  
Visible Effect ◽  
Thoracic Muscles

The troponin I (TnI) gene of Drosophila melanogaster encodes a family of 10 isoforms resulting from the differential splicing of 13 exons. Four of these exons (6a1, 6a2, 6b1, and 6b2) are mutually exclusive and very similar in sequence. TnI isoforms show qualitative specificity whereby each muscle expresses a selected repertoire of them. In addition, TnI isoforms show quantitative specificity whereby each muscle expresses characteristic amounts of each isoform. In the mutant heldup3, the development of the thoracic muscles DLM, DVM, and TDT is aborted. The mutation consists of a one-nucleotide displacement of the 3' AG splice site at the intron preceding exon 6b1, resulting in the failure to produce all exon 6b1-containing TnI isoforms. These molecular changes in a constituent of the thin filaments cause the selective failure to develop the DLM, DVM, and TDT muscles while having no visible effect on other muscles wherein exon 6b1 expression is minor.

scholarly journals Muscle abnormalities in Drosophila melanogaster heldup mutants are caused by missing or aberrant troponin-I isoforms.

1991 ◽  
Vol 114 (5) ◽  
pp. 941-951 ◽  
Author(s):  
C J Beall ◽  
E Fyrberg
Keyword(s):  
Drosophila Melanogaster ◽  
Thin Filament ◽  
Null Allele ◽  
Troponin I ◽  
Chain Gene ◽  
Muscle Degeneration ◽  
Thin Filaments ◽  
Functional Defect ◽  
Flight Muscles ◽  
Molecular Bases

We have investigated the molecular bases of muscle abnormalities in four Drosophila melanogaster heldup mutants. We find that the heldup gene encodes troponin-I, one of the principal regulatory proteins associated with skeletal muscle thin filaments. heldup3, heldup4, and heldup5 mutants, all of which have grossly abnormal flight muscle myofibrils, lack mRNAs encoding one or more troponin-I isoforms. In contrast, heldup2, an especially interesting mutant wherein flight muscles are atrophic, synthesizes the complete mRNA complement. By sequencing mutant troponin-I cDNAs we demonstrate that the molecular basis for muscle degeneration in heldup2 is conversion of an invariant alanine residue to valine. We finally show that degeneration of heldup2 thin filament/Z-disc networks can be prevented by eliminating thick filaments from flight muscles using a null allele of the sarcomeric myosin heavy chain gene. This latter observation suggests that actomyosin interactions exacerbate the structural or functional defect resulting from the troponin-I mutation.

Calcium-induced movement of troponin-I relative to actin in skeletal muscle thin filaments

Science ◽  
1990 ◽  
Vol 247 (4948) ◽  
pp. 1339-1341 ◽  
Author(s):  
T Tao ◽  
B. Gong ◽  
P. Leavis
Keyword(s):  
Skeletal Muscle ◽  
Troponin I ◽  
Thin Filaments

scholarly journals Rbfox1 is required for myofibril development and maintaining fiber type–specific isoform expression in Drosophila muscles

2022 ◽  
Vol 5 (4) ◽  
pp. e202101342
Author(s):  
Elena Nikonova ◽  
Amartya Mukherjee ◽  
Ketaki Kamble ◽  
Christiane Barz ◽  
Upendra Nongthomba ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Muscle Development ◽  
Rna Binding ◽  
Troponin I ◽  
Rna Binding Proteins ◽  
Fiber Type ◽  
Structural Defects ◽  
Specific Gene ◽  
Fiber Types ◽  
Isoform Expression

Protein isoform transitions confer muscle fibers with distinct properties and are regulated by differential transcription and alternative splicing. RNA-binding Fox protein 1 (Rbfox1) can affect both transcript levels and splicing, and is known to contribute to normal muscle development and physiology in vertebrates, although the detailed mechanisms remain obscure. In this study, we report that Rbfox1 contributes to the generation of adult muscle diversity in Drosophila. Rbfox1 is differentially expressed among muscle fiber types, and RNAi knockdown causes a hypercontraction phenotype that leads to behavioral and eclosion defects. Misregulation of fiber type–specific gene and splice isoform expression, notably loss of an indirect flight muscle–specific isoform of Troponin-I that is critical for regulating myosin activity, leads to structural defects. We further show that Rbfox1 directly binds the 3′-UTR of target transcripts, regulates the expression level of myogenic transcription factors myocyte enhancer factor 2 and Salm, and both modulates expression of and genetically interacts with the CELF family RNA-binding protein Bruno1 (Bru1). Rbfox1 and Bru1 co-regulate fiber type–specific alternative splicing of structural genes, indicating that regulatory interactions between FOX and CELF family RNA-binding proteins are conserved in fly muscle. Rbfox1 thus affects muscle development by regulating fiber type–specific splicing and expression dynamics of identity genes and structural proteins.

scholarly journals Indirect flight muscles in Drosophila melanogaster as a tractable model to study muscle development and disease

2020 ◽  
Vol 64 (1-2-3) ◽  
pp. 167-173
Author(s):  
Saroj Jawkar ◽  
Upendra Nongthomba
Keyword(s):  
Drosophila Melanogaster ◽  
Muscle Development ◽  
Myoblast Fusion ◽  
Successful Development ◽  
Adult Muscle ◽  
Attachment Sites ◽  
Flight Muscles ◽  
And Function

Myogenesis is a complex multifactorial process leading to the formation of the adult muscle. An amalgamation of autonomous processes including myoblast fusion and myofibrillogenesis, as well as non-autonomous processes, such as innervations from neurons and precise connections with attachment sites, are responsible for successful development and function of muscles. In this review, we describe the development of the indirect flight muscles (IFMs) in Drosophila melanogaster, and highlight the use of the IFMs as a model for studying muscle development and disease, based on recent studies on the development and function of IFMs.

scholarly journals Bisphosphorylation of cardiac troponin I modulates the Ca2+-dependent binding of myosin subfragment S1 to reconstituted thin filaments

FEBS Letters ◽  
1996 ◽  
Vol 384 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Silke U. Reiffert ◽  
Kornelia Jaquet ◽  
Ludwig M.G. Heilmeyer ◽  
Marcia D. Ritchie ◽  
Michael A. Geeves
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Cardiac Troponin I ◽  
Thin Filaments ◽  
Myosin Subfragment

scholarly journals Intronic PAH gene mutations cause a splicing defect by a novel mechanism involving U1snRNP binding downstream of the 5’ splice site

PLoS Genetics ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. e1007360 ◽  
Author(s):  
Ainhoa Martínez-Pizarro ◽  
Maja Dembic ◽  
Belén Pérez ◽  
Brage S. Andresen ◽  
Lourdes R. Desviat
Keyword(s):  
Splice Site ◽  
Gene Mutations ◽  
Splicing Defect ◽  
Pah Gene

scholarly journals Imaginal Pioneers Prefigure the Formation of Adult Thoracic Muscles in Drosophila melanogaster

2000 ◽  
Vol 222 (2) ◽  
pp. 450-459 ◽  
Author(s):  
Patricia K. Rivlin ◽  
Anne M. Schneiderman ◽  
Ronald Booker
Keyword(s):  
Drosophila Melanogaster ◽  
Thoracic Muscles
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