Characterization of mutant alleles of myospheroid, the gene encoding the beta subunit of the Drosophila PS integrins.

Genetics ◽  
1992 ◽  
Vol 132 (2) ◽  
pp. 519-528 ◽  
Author(s):  
T A Bunch ◽  
R Salatino ◽  
M C Engelsgjerd ◽  
L Mukai ◽  
R F West ◽  
...  
Keyword(s):  
Chromosome Pairing ◽  
Protein Product ◽  
Beta Subunit ◽  
Wild Type ◽  
Muscle Attachment ◽  
Negative Interaction ◽  
Gene Encoding ◽  
Attachment Sites ◽  
Muscle Attachment Sites

Abstract This paper presents the characterization of nine alleles of myospheroid, which encodes the beta PS subunit of the Drosophila PS integrins. On Southern blots, the mysXB87, mysXN101 and mysXR04 genes yield restriction digest patterns similar to that seen for wild-type chromosomes, however the mys1 and mysXG43 genes contain detectable deletions. mys1, mysXB87 and mysXG43 make little or no stable protein product, and genetically behave as strong lethal alleles. For the mysXN101 mutation, protein product is seen on immunoblots and a reduced amount of beta PS protein is seen at muscle attachment sites of embryos; this mutant protein retains some wild-type function, as revealed by complementation tests with weak alleles. Protein is also seen on immunoblots from mysXR04 embryos, and this allele behaves as an antimorph, being more deleterious in some crosses than the complete deficiency for the locus. mysts2 and mysnj42 are typically lethal in various combinations with other alleles at high temperatures only, but even at high physiological temperatures, neither appears to eliminate gene function completely. The complementation behaviors of mysts1 and mysts3 are quite unusual and suggest that these mutations involve regulatory phenomena. For mysts3, the data are most easily explained by postulating transvection effects at the locus. The results for mysts1 are less straightforward, but point to the possibility of a chromosome pairing-dependent negative interaction.

Morphology of muscle attachment sites and microarhitecture of underlying bone as the markers of physical activities of past populations

2013 ◽  
Author(s):  
Ksenija Djukic ◽  
Petar Milovanovic ◽  
Michael Hahn ◽  
Bjoern Busse ◽  
Michael Amling ◽  
...  
Keyword(s):  
Physical Activities ◽  
Muscle Attachment ◽  
Attachment Sites ◽  
Muscle Attachment Sites

Molecular characterization of three mutations in katG affecting the activity of hydroperoxidase I of Escherichia coli

1990 ◽  
Vol 68 (7-8) ◽  
pp. 1037-1044 ◽  
Author(s):  
Peter C. Loewen ◽  
Jacek Switala ◽  
Mark Smolenski ◽  
Barbara L. Triggs-Raine
Keyword(s):  
Escherichia Coli ◽  
Specific Activity ◽  
Polymerase Chain Reaction Amplification ◽  
Protein A ◽  
Wild Type ◽  
Wild Type Enzyme ◽  
Gene Encoding ◽  
Reaction Amplification ◽  
Mutant Genes

Hydroperoxidase I (HPI) of Escherichia coli is a bifunctional enzyme exhibiting both catalase and peroxidase activities. Mutants lacking appreciable HPI have been generated using nitrosoguanidine and the gene encoding HPI, katG, has been cloned from three of these mutants using either classical probing methods or polymerase chain reaction amplification. The mutant genes were sequenced and the changes from wild-type sequence identified. Two mutants contained G to A changes in the coding strand, resulting in glycine to aspartate changes at residues 119 (katG15) and 314 (katG16) in the deduced amino acid sequence of the protein. A third mutant contained a C to T change resulting in a leucine to phenylalanine change at residue 139 (katG14). The Phe139-, Asp119-, and Asp314-containing mutants exhibited 13, < 1, and 18%, respectively, of the wild-type catalase specific activity and 43, 4, and 45% of the wild-type peroxidase specific activity. All mutant enzymes bound less protoheme IX than the wild-type enzyme. The sensitivities of the mutant enzymes to the inhibitors hydroxylamine, azide, and cyanide and the activators imidazole and Tris were similar to those of the wild-type enzyme. The mutant enzymes were more sensitive to high temperature and to β-mercaptoethanol than the wild-type enzyme. The pH profiles of the mutant catalases were unchanged from the wild-type enzyme.Key words: catalase, hydroperoxidase I, mutants, sequence analysis.

A novel basic helix-loop-helix protein is expressed in muscle attachment sites of the Drosophila epidermis

1994 ◽  
Vol 14 (6) ◽  
pp. 4145-4154
Author(s):  
P Armand ◽  
A C Knapp ◽  
A J Hirsch ◽  
E F Wieschaus ◽  
M D Cole
Keyword(s):  
Distinct Pattern ◽  
Bhlh Protein ◽  
Muscle Attachment ◽  
Muscle Creatine Kinase ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Attachment Sites ◽  
Bhlh Genes ◽  
Somatic Muscles ◽  
Muscle Attachment Sites

We have found that a novel basic helix-loop-helix (bHLH) protein is expressed almost exclusively in the epidermal attachments sites for the somatic muscles of Drosophila melanogaster. A Drosophila cDNA library was screened with radioactively labeled E12 protein, which can dimerize with many HLH proteins. One clone that emerged from this screen encoded a previously unknown protein of 360 amino acids, named delilah, that contains both basic and HLH domains, similar to a group of cellular transcription factors implicated in cell type determination. Delilah protein formed heterodimers with E12 that bind to the muscle creatine kinase promoter. In situ hybridization with the delilah cDNA localized the expression of the gene to a subset of cells in the epidermis which form a distinct pattern involving both the segmental boundaries and intrasegmental clusters. This pattern was coincident with the known sites of attachment of the somatic muscles to tendon cells in the epidermis. delilah expression persists in snail mutant embryos which lack mesoderm, indicating that expression of the gene was not induced by attachment of the underlying muscles. The similarity of this gene to other bHLH genes suggests that it plays an important role in the differentiation of epidermal cells into muscle attachment sites.

Epidermal tendon cells require Broad Complex function for correct attachment of the indirect flight muscles in Drosophila melanogaster

1999 ◽  
Vol 112 (22) ◽  
pp. 4051-4065 ◽  
Author(s):  
D.J. Sandstrom ◽  
L.L. Restifo
Keyword(s):  
Complex Function ◽  
Myotendinous Junction ◽  
Wild Type ◽  
Muscle Attachment ◽  
Attachment Sites ◽  
Tendon Cells ◽  
Flight Muscles ◽  
Broad Complex ◽  
Developing Muscle ◽  
Dorsal Epidermis

Drosophila Broad Complex, a primary response gene in the ecdysone cascade, encodes a family of zinc-finger transcription factors essential for metamorphosis. Broad Complex mutations of the rbp complementation group disrupt attachment of the dorsoventral indirect flight muscles during pupal development. We previously demonstrated that isoform BRC-Z1 mediates the muscle attachment function of rbp(+) and is expressed in both developing muscle fibers and their epidermal attachment sites. We now report two complementary studies to determine the cellular site and mode of action of rbp(+) during maturation of the myotendinous junctions of dorsoventral indirect flight muscles. First, genetic mosaics, produced using the paternal loss method, revealed that the muscle attachment phenotype is determined primarily by the genotype of the dorsal epidermis, with the muscle fiber and the ventral epidermis exerting little or no influence. When the dorsal epidermis was mutant, the vast majority of muscles detached or chose ectopic attachment sites, regardless of the muscle genotype. Conversely, wild-type dorsal epidermis could support attachment of mutant muscles. Second, ultrastructural analysis corroborated and extended these results, revealing defective and delayed differentiation of rbp mutant epidermal tendon cells in the dorsal attachment sites. Tendon cell processes, the stress-bearing links between the epidermis and muscle, were reduced in number and showed delayed appearance of microtubule bundles. In contrast, mutant muscle and ventral epidermis resembled the wild type. In conclusion, BRC-Z1 acts in the dorsal epidermis to ensure differentiation of the myotendinous junction. By analogy with the cell-cell interaction essential for embryonic muscle attachment, we propose that BRC-Z1 regulates one or more components of the epidermal response to a signal from the developing muscle.

scholarly journals wing blister, A New Drosophila Laminin α Chain Required for Cell Adhesion and Migration during Embryonic and Imaginal Development

1999 ◽  
Vol 145 (1) ◽  
pp. 191-201 ◽  
Author(s):  
Doris Martin ◽  
Susan Zusman ◽  
Xitong Li ◽  
Erin L. Williams ◽  
Narmada Khare ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Functional Characterization ◽  
Specific Pattern ◽  
Basement Membranes ◽  
Muscle Attachment ◽  
Attachment Sites ◽  
Cell Adhesion And Migration ◽  
Α Chain ◽  
Embryonic Viability ◽  
Muscle Attachment Sites

We report the molecular and functional characterization of a new α chain of laminin in Drosophila. The new laminin chain appears to be the Drosophila counterpart of both vertebrate α2 (also called merosin) and α1 chains, with a slightly higher degree of homology to α2, suggesting that this chain is an ancestral version of both α1 and α2 chains. During embryogenesis, the protein is associated with basement membranes of the digestive system and muscle attachment sites, and during larval stage it is found in a specific pattern in wing and eye discs. The gene is assigned to a locus called wing blister (wb), which is essential for embryonic viability. Embryonic phenotypes include twisted germbands and fewer pericardial cells, resulting in gaps in the presumptive heart and tracheal trunks, and myotubes detached from their target muscle attachment sites. Most phenotypes are in common with those observed in Drosophila laminin α3, 5 mutant embryos and many are in common with those observed in integrin mutations. Adult phenotypes show blisters in the wings in viable allelic combinations, similar to phenotypes observed in integrin genes. Mutation analysis in the eye demonstrates a function in rhabdomere organization. In summary, this new laminin α chain is essential for embryonic viability and is involved in processes requiring cell migration and cell adhesion.

scholarly journals A small proportion of Talin molecules transmit forces to achieve muscle attachment in vivo

2018 ◽  
Author(s):  
Sandra B. Lemke ◽  
Thomas Weidemann ◽  
Anna-Lena Cost ◽  
Carsten Grashoff ◽  
Frank Schnorrer
Keyword(s):  
Tissue Mechanics ◽  
Correlation Spectroscopy ◽  
Mechanical Forces ◽  
Muscle Attachment ◽  
Cell Fate Decisions ◽  
Mammalian Cell Lines ◽  
Attachment Sites ◽  
Molecular Forces ◽  
Muscle Attachment Sites

Cells in a developing organism are subjected to particular mechanical forces, which shape tissues and instruct cell fate decisions. How these forces are sensed and transmitted at the molecular level is thus an important question, which has mainly been investigated in cultured cells in vitro. Here, we elucidate how mechanical forces are transmitted in an intact organism. We studied Drosophila muscle attachment sites, which experience high mechanical forces during development and require integrin-mediated adhesion for stable attachment to tendons. Hence, we quantified molecular forces across the essential integrin-binding protein Talin, which links integrin to the actin cytoskeleton. Generating flies expressing three FRET-based Talin tension sensors reporting different force levels between 1 and 11 pN enabled us to quantify physiologically-relevant, molecular forces. By measuring primary Drosophila muscle cells, we demonstrate that Drosophila Talin experiences mechanical forces in cell culture that are similar to those previously reported for Talin in mammalian cell lines. However, in vivo force measurements at developing flight muscle attachment sites revealed that average forces across Talin are comparatively low and decrease even further while attachments mature and tissue-level tension increases. Concomitantly, Talin concentration at attachment sites increases five-fold as quantified by fluorescence correlation spectroscopy, suggesting that only few Talin molecules are mechanically engaged at any given time. We therefore propose that high tissue forces are shared amongst a large excess of adhesion molecules of which less than 15% are experiencing detectable forces at the same time. Our findings define an important new concept of how cells can adapt to changes in tissue mechanics to prevent mechanical failure in vivo.

Characterization of yeast V-ATPase mutants lacking Vph1p or Stv1p and the effect on endocytosis

2002 ◽  
Vol 205 (9) ◽  
pp. 1209-1219 ◽  
Author(s):  
Natalie Perzov ◽  
Vered Padler-Karavani ◽  
Hannah Nelson ◽  
Nathan Nelson
Keyword(s):  
Sucrose Gradient ◽  
Ph Sensor ◽  
Wild Type ◽  
Gene Encoding ◽  
Yeast Saccharomyces Cerevisiae ◽  
Vacuolar Acidification ◽  
Atpase Subunits ◽  
Immunological Assays ◽  
Gradient Fractionation

SUMMARYSubunit a of V-ATPase in the yeast Saccharomyces cerevisiae, in contrast to its other subunits, is encoded by two genes VPH1 and STV1. While disruption of any other gene encoding the V-ATPase subunits results in growth arrest at pH 7.5, null mutants of Vph1p or Stv1p can grow at this pH. We used a polyclonal antibody to yeast Stv1p and a commercially available monoclonal antibody to Vph1p for analysis of yeast membranes by sucrose gradient fractionation, and two different vital dyes to characterize the phenotype of vph1 ▵ and stv1 ▵mutants as compared to the double mutant and the wild-type cells. Immunological assays of sucrose gradient fractions revealed that the amount of Stv1p was elevated in the vph1 ▵ strain, and that vacuoles purified by this method with no detectable endosomal contamination contain an assembled V-ATPase complex, but with much lower activity than the wild type. These results suggest that Stv1p compensates for the loss of Vph1p in the vph1 ▵ strain. LysoSensor Green DND-189 was used as a pH sensor to demonstrate unexpected changes in vacuolar acidification in stv1▵ as the Vph1p-containing V-ATPase complex is commonly considered to acidify the vacuoles. In the vph1 ▵ strain, the dye revealed slight but definite acidification of the vacuole as well. The lipophilic dye FM4-64 was used as an endocytic marker. We show that the null V-ATPase mutants, as well as the vph1 ▵ one, markedly slow down endocytosis of the dye.

scholarly journals Odyssey in the evolution of a paleopathologist

Fossil Record ◽  
2016 ◽  
Vol 20 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Bruce M. Rothschild
Keyword(s):  
Medical Science ◽  
Critical Factor ◽  
Human Migration ◽  
Proof Of Concept ◽  
Sources Of Information ◽  
Muscle Attachment ◽  
Attachment Sites ◽  
Similar Disease ◽  
Meta Analyses ◽  
Muscle Attachment Sites

Abstract. A recent report suggesting perceived limitations of and opportunities in the study of paleopathology suggested the importance of incorporation of scientific methodologies. It seems reasonable to also explore how those methodologies are developed and, indeed, how one approaches paleopathology as a science. The development of one such paleopathologist is delineated from his serendipitous observations to application of hypothesis generation and subsequent testing approach developed during basic medical science education. This approach resulted in recognition of how much he thought he knew was actually contrary to the facts. A critical factor was the collaborative approach with specialists in other fields, wherein linguistic confusion was overcome and perspectives refined by point–counterpoint analysis of hypotheses. The limited reliability of tertiary information was clearly exposed through examination of primary sources – original articles rather than what might be referred to as "meta-analyses". It became clear that linguistics was not the only challenge; application of techniques had to be observed and validated. Without validation one might obtain precision (method repeatedly reveals same results) but at the expense of accuracy (assurance that the method actually assesses the question). Paleontological studies are generally limited to examination of organisms and their traces. Archeologically based studies incorporate additional sources of information (e.g., historic), but are no less subject to such semantic and methodological issues. Proof of concept studies provided new windows to recognition not only of disease but to previous anatomical challenges (e.g., localization of direct muscle attachment sites and distribution). Trans-phylogenetic representation of disease falsified speculation that "evolution" would preclude analysis through time. Pathology is an intrinsic component of life and transcends both species and time. Knowledge gained in a given species and time can be applied to similar disease manifestations in other species in modern time. Once speculations were tested and either verified or falsified, paleo-epidemiologic approach allowed identification of patterns of spread and even application of that knowledge to recognition of human migration patterns. Proof of concept studies provided new windows to recognition not only of disease but to previous anatomical challenges (e.g., localization of direct muscle attachment sites and distribution).

Sign in / Sign up

Export Citation Format

Share Document