scholarly journals Deletion of the Dynein Heavy-Chain Gene DYN1 Leads to Aberrant Nuclear Positioning and Defective Hyphal Development in Candida albicans

2004 ◽  
Vol 3 (6) ◽  
pp. 1574-1588 ◽  
Author(s):  
R. Martin ◽  
A. Walther ◽  
J. Wendland
Keyword(s):  
Candida Albicans ◽  
Heavy Chain ◽  
Time Lapse ◽  
Yeast Cells ◽  
Chain Gene ◽  
Wild Type ◽  
Heavy Chain Gene ◽  
Mutant Strains ◽  
Mutant Phenotypes

ABSTRACT Cytoplasmic dynein is a microtubule-associated minus-end-directed motor protein. CaDYN1 encodes the single dynein heavy-chain gene of Candida albicans. The open reading frames of both alleles of CaDYN1 were completely deleted via a PCR-based approach. Cadyn1 mutants are viable but grow more slowly than the wild type. In vivo time-lapse microscopy was used to compare growth of wild-type (SC5314) and dyn1 mutant strains during yeast growth and after hyphal induction. During yeast-like growth, Cadyn1 strains formed chains of cells. Chromosomal TUB1-GFP and HHF1-GFP alleles were used both in wild-type and mutant strains to monitor the orientation of mitotic spindles and nuclear positioning in C. albicans. In vivo fluorescence time-lapse analyses with HHF1-GFP over several generations indicated defects in dyn1 cells in the realignment of spindles with the mother-daughter axis of yeast cells compared to that of the wild type. Mitosis in the dyn1 mutant, in contrast to that of wild-type yeast cells, was very frequently completed in the mother cells. Nevertheless, daughter nuclei were faithfully transported into the daughter cells, resulting in only a small number of multinucleate cells. Cadyn1 mutant strains responded to hypha-inducing media containing l-proline or serum with initial germ tube formation. Elongation of the hyphal tubes eventually came to a halt, and these tubes showed a defect in the tipward localization of nuclei. Using a heterozygous DYN1/dyn1 strain in which the remaining copy was controlled by the regulatable MAL2 promoter, we could switch between wild-type and mutant phenotypes depending on the carbon source, indicating that the observed mutant phenotypes were solely due to deletion of DYN1.

scholarly journals Transformation of Drosophila melanogaster with the wild-type myosin heavy-chain gene: rescue of mutant phenotypes and analysis of defects caused by overexpression.

1994 ◽  
Vol 126 (3) ◽  
pp. 689-699 ◽  
Author(s):  
R M Cripps ◽  
K D Becker ◽  
M Mardahl ◽  
W A Kronert ◽  
D Hodges ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Copy Number ◽  
Chain Gene ◽  
Wild Type ◽  
Heavy Chain Gene ◽  
Myosin Heavy Chain Gene ◽  
Flight Muscles ◽  
Mutant Phenotypes

We have transformed Drosophila melanogaster with a genomic construct containing the entire wild-type myosin heavy-chain gene, Mhc, together with approximately 9 kb of flanking DNA on each side. Three independent lines stably express myosin heavy-chain protein (MHC) at approximately wild-type levels. The MHC produced is functional since it rescues the mutant phenotypes of a number of different Mhc alleles: the amorphic allele Mhc1, the indirect flight muscle and jump muscle-specific amorphic allele Mhc10, and the hypomorphic allele Mhc2. We show that the Mhc2 mutation is due to the insertion of a transposable element in an intron of Mhc. Since a reduction in MHC in the indirect flight muscles alters the myosin/actin protein ratio and results in myofibrillar defects, we determined the effects of an increase in the effective copy number of Mhc. The presence of four copies of Mhc results in overabundance of the protein and a flightless phenotype. Electron microscopy reveals concomitant defects in the indirect flight muscles, with excess thick filaments at the periphery of the myofibrils. Further increases in copy number are lethal. These results demonstrate the usefulness and potential of the transgenic system to study myosin function in Drosophila. They also show that overexpression of wild-type protein in muscle may disrupt the function of not only the indirect flight but also other muscles of the organism.

IN VIVO GENE REGULATION OF THE ?? MYOSIN HEAVY CHAIN GENE IN RODENT HEART

1998 ◽  
Vol 30 (Supplement) ◽  
pp. 143
Author(s):  
C. E Wright ◽  
F. Haddad ◽  
P. W. Bodell ◽  
K. M. Baldwin
Keyword(s):  
Gene Regulation ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Chain Gene ◽  
Heavy Chain Gene ◽  
Myosin Heavy Chain Gene

scholarly journals Allelic exclusion in transgenic mice carrying mutant human IgM genes.

1988 ◽  
Vol 167 (6) ◽  
pp. 1969-1974 ◽  
Author(s):  
M C Nussenzweig ◽  
A C Shaw ◽  
E Sinn ◽  
J Campos-Torres ◽  
P Leder
Keyword(s):  
Transgenic Mice ◽  
Heavy Chain ◽  
Chain Gene ◽  
Allelic Exclusion ◽  
Heavy Chain Gene ◽  
F1 Hybrid ◽  
Membrane Bound ◽  
Ig Heavy Chain ◽  
Simultaneous Expression

Expression of the membrane-bound version of the human mu chain in transgenic mice results in the allelic exclusion of endogenous mouse Ig heavy chain genes (6). The secreted version of the human Ig transgene has no such effect. F1 hybrid animals that carry transgenes for both secreted and membrane-bound human mu chains produce both forms of the human heavy chain while strongly suppressing endogenous mouse mu expression. The simultaneous expression of the two rearranged transgenes in primary B cells suggests that allelic exclusion operates before the formation of a second functionally rearranged heavy chain gene in vivo.

scholarly journals Clathrin heavy chain functions in sorting and secretion of lysosomal enzymes in Dictyostelium discoideum.

1994 ◽  
Vol 126 (2) ◽  
pp. 343-352 ◽  
Author(s):  
T Ruscetti ◽  
J A Cardelli ◽  
M L Niswonger ◽  
T J O'Halloran
Keyword(s):  
Dictyostelium Discoideum ◽  
Heavy Chain ◽  
Lysosomal Enzyme ◽  
Lysosomal Enzymes ◽  
Secretory Pathway ◽  
Chain Gene ◽  
Wild Type ◽  
Clathrin Heavy Chain ◽  
Mutant Cells

The clathrin heavy chain is a major component of clathrin-coated vesicles that function in selective membrane traffic in eukaryotic cells. We disrupted the clathrin heavy chain gene (chcA) in Dictyostelium discoideum to generate a stable clathrin heavy chain-deficient cell line. Measurement of pinocytosis in the clathrin-minus mutant revealed a four-to five-fold deficiency in the internalization of fluid-phase markers. Once internalized, these markers recycled to the cell surface of mutant cells at wild-type rates. We also explored the involvement of clathrin heavy chain in the trafficking of lysosomal enzymes. Pulse chase analysis revealed that clathrin-minus cells processed most alpha-mannosidase to mature forms, however, approximately 20-25% of the precursor molecules remained uncleaved, were missorted, and were rapidly secreted by the constitutive secretory pathway. The remaining intracellular alpha-mannosidase was successfully targeted to mature lysosomes. Standard secretion assays showed that the rate of secretion of alpha-mannosidase was significantly less in clathrin-minus cells compared to control cells in growth medium. Interestingly, the secretion rates of another lysosomal enzyme, acid phosphatase, were similar in clathrin-minus and wild-type cells. Like wild-type cells, clathrin-minus mutants responded to starvation conditions with increased lysosomal enzyme secretion. Our study of the mutant cells provide in vivo evidence for roles for the clathrin heavy chain in (a) the internalization of fluid from the plasma membrane; (b) sorting of hydrolase precursors from the constitutive secretory pathway to the lysosomal pathway; and (c) secretion of mature hydrolases from lysosomes to the extracellular space.

Developmental pattern of mouse skeletal myosin heavy chain gene transcripts in vivo and in vitro

Cell ◽  
1987 ◽  
Vol 49 (1) ◽  
pp. 121-129 ◽  
Author(s):  
André Weydert ◽  
Paul Barton ◽  
A.John Harris ◽  
Christian Pinset ◽  
Margaret Buckingham
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Developmental Pattern ◽  
Chain Gene ◽  
Heavy Chain Gene ◽  
Myosin Heavy Chain Gene ◽  
Skeletal Myosin ◽  
Gene Transcripts

Articular, monoclonal γ3 heavy-chain deposition disease: Characterization of a partially deleted heavy-chain gene and its protein product synthesized in vivo and in vitro

2003 ◽  
Vol 48 (11) ◽  
pp. 3266-3271 ◽  
Author(s):  
Keith M. Thompson ◽  
Knut Sletten ◽  
Per Brandtzaeg ◽  
Eva Källberg ◽  
Tale Norbye Wien ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Protein Product ◽  
Chain Gene ◽  
Heavy Chain Gene ◽  
Deposition Disease ◽  
Heavy Chain Deposition Disease

scholarly journals In vivo analysis of the murine beta-myosin heavy chain gene promoter.

1993 ◽  
Vol 268 (7) ◽  
pp. 5332-5338
Author(s):  
H. Rindt ◽  
J. Gulick ◽  
S. Knotts ◽  
J. Neumann ◽  
J. Robbins
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Gene Promoter ◽  
Chain Gene ◽  
Heavy Chain Gene ◽  
Myosin Heavy Chain Gene ◽  
In Vivo Analysis

scholarly journals Cytoplasmic Dynein Is Required for the Nuclear Attachment and Migration of Centrosomes during Mitosis in Drosophila

1999 ◽  
Vol 146 (3) ◽  
pp. 597-608 ◽  
Author(s):  
John T. Robinson ◽  
Edward J. Wojcik ◽  
Mark A. Sanders ◽  
Maura McGrail ◽  
Thomas S. Hays
Keyword(s):  
Heavy Chain ◽  
Spatial Organization ◽  
Critical Role ◽  
Genetic System ◽  
Cytoplasmic Dynein ◽  
Chain Gene ◽  
Wild Type ◽  
Dynein Heavy Chain ◽  
And Migration

Cytoplasmic dynein is a multisubunit minus-end–directed microtubule motor that serves multiple cellular functions. Genetic studies in Drosophila and mouse have demonstrated that dynein function is essential in metazoan organisms. However, whether the essential function of dynein reflects a mitotic requirement, and what specific mitotic tasks require dynein remains controversial. Drosophila is an excellent genetic system in which to analyze dynein function in mitosis, providing excellent cytology in embryonic and somatic cells. We have used previously characterized recessive lethal mutations in the dynein heavy chain gene, Dhc64C, to reveal the contributions of the dynein motor to mitotic centrosome behavior in the syncytial embryo. Embryos lacking wild-type cytoplasmic dynein heavy chain were analyzed by in vivo analysis of rhodamine-labeled microtubules, as well as by immu-nofluorescence in situ methods. Comparisons between wild-type and Dhc64C mutant embryos reveal that dynein function is required for the attachment and migration of centrosomes along the nuclear envelope during interphase/prophase, and to maintain the attachment of centrosomes to mitotic spindle poles. The disruption of these centrosome attachments in mutant embryos reveals a critical role for dynein function and centrosome positioning in the spatial organization of the syncytial cytoplasm of the developing embryo.

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