Abductor Pollicis Longus: A Case of Mistaken Identity

1992 ◽  
Vol 17 (4) ◽  
pp. 476-478 ◽  
Author(s):  
B. G. ELLIOTT
Keyword(s):  
The Other ◽  
Loss Of Function ◽  
Mistaken Identity ◽  
Abductor Pollicis Longus ◽  
Radial Deviation

Abductor pollicis longus, long regarded as a motor for the thumb, is anatomically and functionally a radial deviator of the wrist and should be so named. The abductor carpi is proposed. If the other radial deviators of the wrist are acting this tendon can be selectively utilized as a transfer without loss of function. Reflex spasm of this muscle probably plays an important role in the radial deviation deformity seen in the rheumatoid hand.

scholarly journals act Operon Control of Developmental Gene Expression in Myxococcus xanthus

2002 ◽  
Vol 184 (4) ◽  
pp. 1172-1179 ◽  
Author(s):  
Thomas M. A. Gronewold ◽  
Dale Kaiser
Keyword(s):  
Fruiting Body ◽  
Myxococcus Xanthus ◽  
The Other ◽  
Loss Of Function ◽  
Wild Type ◽  
Developmental Gene ◽  
Developmental Gene Expression ◽  
Mutant Strains ◽  
Genes Encoding ◽  
Signal Production

ABSTRACT Cell-bound C-signal guides the building of a fruiting body and triggers the differentiation of myxospores. Earlier work has shown that transcription of the csgA gene, which encodes the C-signal, is directed by four genes of the act operon. To see how expression of the genes encoding components of the aggregation and sporulation processes depends on C-signaling, mutants with loss-of-function mutations in each of the act genes were investigated. These mutations were found to have no effect on genes that are normally expressed up to 3 h into development and are C-signal independent. Neither the time of first expression nor the rate of expression increase was changed in actA, actB, actC, or actD mutant strains. Also, there was no effect on A-signal production, which normally starts before 3 h. By contrast, the null act mutants have striking defects in C-signal production. These mutations changed the expression of four gene reporters that are related to aggregation and sporulation and are expressed at 6 h or later in development. The actA and actB null mutations substantially decreased the expression of all these reporters. The other act null mutations caused either premature expression to wild-type levels (actC) or delayed expression (actD), which ultimately rose to wild-type levels. The pattern of effects on these reporters shows how the C-signal differentially regulates the steps that together build a fruiting body and differentiate spores within it.

scholarly journals Characterization of an Unstable Allele of the Arabidopsis HY4 Locus

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1575-1585
Author(s):  
Edward P Bruggemann ◽  
Bernard Doan ◽  
Korie Handwerger ◽  
Gisela Storz
Keyword(s):  
Fast Neutron ◽  
Blue Light ◽  
Large Deletion ◽  
The Other ◽  
Epigenetic Mechanisms ◽  
Loss Of Function ◽  
Wild Type ◽  
Unusual Behavior ◽  
Recessive Lethal

Abstract The Arabidopsis HY4 gene encodes the nonessential blue light photoreceptor CRY1. Loss-of-function hy4 mutants have an elongated hypocotyl phenotype after germination under blue light. We previously analyzed 20 independent hy4 alleles produced by fast neutron mutagenesis. These alleles were grouped into two classes based on their genetic behavior and corresponding deletion size: (1) null hy4 alleles that were semidominant over wild type and contained small or moderate-sized deletions at HY4 and (2) null hy4 alleles that were recessive lethal and contained large HY4 deletions. Here we describe one additional fast neutron hy4 mutant, B144, that did not fall into either of these two classes. Mutant B144 was isolated as a heterozygote with an intermediate hy4 phenotype. One allele from this mutant, hy4-B144Δ, contains a large deletion at HY4 and is recessive lethal. The other allele from this mutant, HY4-B144*, appears to be intact and functional but is unstable and spontaneously converts to a nonfunctional hy4 allele. In addition, HY4-B144* is lethal in homozygotes and suppresses local recombination. We discuss genetic and epigenetic mechanisms that may account for the unusual behavior of the HY4-B144* allele.

scholarly journals Correction to: DNMT3A reads and connects histone H3K36me2 to DNA methylation

2019 ◽  
Vol 11 (3) ◽  
pp. 230-230
Author(s):  
Wenqi Xu ◽  
Jiahui Li ◽  
Bowen Rong ◽  
Bin Zhao ◽  
Mei Wang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Histone Mark ◽  
The Other ◽  
Therapeutic Implication ◽  
Loss Of Function ◽  
Function Model ◽  
Gain Of Function ◽  
Intergenic Dna ◽  
Preferential Recognition ◽  
Function Models

The author would like to add the below information in this correction. A similar study from Chao Lu group was published online on 5 September 2019 in Nature, entitled “The histone mark H3K36me2 recruits DNMT3A and shapes the intergenic DNA methylation landscape” (Weinberg et al., 2019). Although both the studies reported the preferential recognition of H3K36me2 by DNMT3A PWWP, ours in addition uncovered a stimulation function by such interaction on the activity of DNMT3A. On the disease connections, we used a NSD2 gain-of-function model which led to the discovery of potential therapeutic implication of DNA inhibitors in the related cancers, while the other study only used NSD1 and DNMT3A loss-of-function models.

scholarly journals The segmentation gene runt is needed to activate Sex-lethal, a gene that controls sex determination and dosage compensation in Drosophila

1992 ◽  
Vol 59 (3) ◽  
pp. 189-198 ◽  
Author(s):  
Miguel Torres ◽  
Lucas Sanchez
Keyword(s):  
Sex Determination ◽  
Dosage Compensation ◽  
Relative Number ◽  
Initial Step ◽  
The Other ◽  
Loss Of Function ◽  
X Chromosomes ◽  
Segmentation Gene ◽  
Ectopic Activation ◽  
Sex Lethal

SummaryIn Drosophila, sex is determined by the relative number of X chromosomes to autosomal sets (X: A ratio). The amount of products from several X-linked genes, called sisterless elements, is used to indicate to Sex-lethal the relative number of X chromosomes present in the cell. In response to the X: A signal, Sex-lethal is activated in females but remains inactive in males, being responsible for the control of both sex determination and dosage compensation. Here we find that the X-linked segmentation gene runt plays a role in this process. Reduced function of runt results in femalespecific lethality and sexual transformation of XX animals that are heterozygous for Sxl or sis loss-of-function mutations. These interactions are suppressed by SxlMI, a mutation that constitutively expresses female Sex-lethal functions, and occur at the time when the X: A signal determines Sex-lethal activity. Moreover, the presence of a loss-of-function runt mutation masculinizes triploid intersexes. On the other hand, runt duplications cause a reduction in male viability by ectopic activation of Sex-lethal. We conclude that runt is needed for the initial step of Sex-lethal activation, but does not have a major role as an X-counting element.

scholarly journals Phosphatidylinositol 4,5-bisphosphate Directs Spermatid Cell Polarity and Exocyst Localization in Drosophila

2010 ◽  
Vol 21 (9) ◽  
pp. 1546-1555 ◽  
Author(s):  
Lacramioara Fabian ◽  
Ho-Chun Wei ◽  
Janet Rollins ◽  
Tatsuhiko Noguchi ◽  
J. Todd Blankenship ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Plasma Membrane ◽  
Cell Polarity ◽  
The Other ◽  
Biosynthetic Enzyme ◽  
Loss Of Function ◽  
Partial Loss ◽  
Sperm Tail ◽  
Low Level ◽  
Exocyst Complex

During spermiogenesis, Drosophila melanogaster spermatids coordinate their elongation in interconnected cysts that become highly polarized, with nuclei localizing to one end and sperm tail growth occurring at the other. Remarkably little is known about the signals that drive spermatid polarity and elongation. Here we identify phosphoinositides as critical regulators of these processes. Reduction of plasma membrane phosphatidylinositol 4,5-bisphosphate (PIP2) by low-level expression of the PIP2 phosphatase SigD or mutation of the PIP2 biosynthetic enzyme Skittles (Sktl) results in dramatic defects in spermatid cysts, which become bipolar and fail to fully elongate. Defects in polarity are evident from the earliest stages of elongation, indicating that phosphoinositides are required for establishment of polarity. Sktl and PIP2 localize to the growing end of the cysts together with the exocyst complex. Strikingly, the exocyst becomes completely delocalized when PIP2 levels are reduced, and overexpression of Sktl restores exocyst localization and spermatid cyst polarity. Moreover, the exocyst is required for polarity, as partial loss of function of the exocyst subunit Sec8 results in bipolar cysts. Our data are consistent with a mechanism in which localized synthesis of PIP2 recruits the exocyst to promote targeted membrane delivery and polarization of the elongating cysts.

scholarly journals Promising Clinical Results of the Universal Total Wrist Prosthesis in Rheumatoid Arthritis

2010 ◽  
Vol 4 (1) ◽  
pp. 67-70 ◽  
Author(s):  
P.J.T.S. van Winterswijk ◽  
P.A.G.M. Bakx
Keyword(s):  
Rheumatoid Arthritis ◽  
Range Of Motion ◽  
Pain Score ◽  
Clinical Results ◽  
The Other ◽  
Study Group ◽  
Ulnar Deviation ◽  
Radial Deviation ◽  
Component Loosening

The purpose of this study was to evaluate the results of the Universal Total Wrist prosthesis.Seventeen wrist arthroplasties were performed in 15 patients using the Universal Total Wrist prosthesis. The 11 women and 4 men in the study group ranged in age from 45 to 86 years. Fourteen patients had rheumatoid arthritis and one had osteoarthritis. Follow up ranged from 20 to 74 months. Patients were evaluated for range of motion, with the Disabilities of the Arm, Shoulder, and Hand (DASH) survey and radiographically.All range of motion values improved after surgery. Average postoperative motion was 29° dorsiflexion, 38° volar flexion, 7° radial deviation and 17° ulnar deviation. The DASH scores improved with 29 %. Pain score improved in all 15 patients. One prosthesis had to be removed due to component loosening of the carpal plate. The other cases showed no radiographic signs of loosening. One patient had an early prosthetic dislocation and was treated conservatively with success.The Universal Total Wrist prosthesis provides a promising outcome in patients with rheumatoid arthritis.

scholarly journals Axial skeletal patterning in mice lacking all paralogous group 8 Hox genes

Development ◽  
2001 ◽  
Vol 128 (10) ◽  
pp. 1911-1921 ◽  
Author(s):  
E. van Den Akker ◽  
C. Fromental-Ramain ◽  
W. de Graaff ◽  
H. Le Mouellic ◽  
P. Brulet ◽  
...  
Keyword(s):  
Hox Genes ◽  
Lumbar Vertebrae ◽  
The Other ◽  
Axial Position ◽  
Loss Of Function ◽  
Axial Region ◽  
Unique Role ◽  
Paralogous Group ◽  
Upper Thoracic ◽  
Redundant Functions

We present a detailed study of the genetic basis of mesodermal axial patterning by paralogous group 8 Hox genes in the mouse. The phenotype of Hoxd8 loss-of-function mutants is presented, and compared with that of Hoxb8- and Hoxc8-null mice. Our analysis of single mutants reveals common features for the Hoxc8 and Hoxd8 genes in patterning lower thoracic and lumbar vertebrae. In the Hoxb8 mutant, more anterior axial regions are affected. The three paralogous Hox genes are expressed up to similar rostral boundaries in the mesoderm, but at levels that strongly vary with the axial position. We find that the axial region affected in each of the single mutants mostly corresponds to the area with the highest level of gene expression. However, analysis of double and triple mutants reveals that lower expression of the other two paralogous genes also plays a patterning role when the mainly expressed gene is defective. We therefore conclude that paralogous group 8 Hox genes are involved in patterning quite an extensive anteroposterior (AP) axial region. Phenotypes of double and triple mutants reveal that Hoxb8, Hoxc8 and Hoxd8 have redundant functions at upper thoracic and sacral levels, including positioning of the hindlimbs. Interestingly, loss of functional Hoxb8 alleles partially rescues the phenotype of Hoxc8- and Hoxc8/Hoxd8-null mutants at lower thoracic and lumbar levels. This suggests that Hoxb8 affects patterning at these axial positions differently from the other paralogous gene products. We conclude that paralogous Hox genes can have a unique role in patterning specific axial regions in addition to their redundant function at other AP levels.

scholarly journals Paralog dependency indirectly affects the robustness of human cells

2019 ◽  
Author(s):  
Rohan Dandage ◽  
Christian R Landry
Keyword(s):  
Gene Loss ◽  
Fitness Landscape ◽  
Human Cells ◽  
The Other ◽  
Gene Copy ◽  
Deleterious Mutations ◽  
Loss Of Function ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
Paralogous Proteins

SummaryGene duplicates provide protection against loss-of-function mutations. This protective redundancy partly relies on the fact that paralogs carry their functions independently, i.e. the inactivation of one gene copy does not impair the function of the other copy. However, a significant fraction of paralogous proteins may form functionally dependent pairs, for instance through heteromerization. As a consequence, one could expect these heteromeric paralogs to be less protective against deleterious mutations. To test this hypothesis, we examined the fitness landscape of gene loss-of-function by CRISPR-Cas9 in more than 450 human cell lines. Our analysis revealed a robustness landscape of human cells showing regions of higher vulnerability to gene inactivation as a function of key paralog properties. We find that heteromerizing paralogs are indeed less protective than non-heteromeric ones, but this association is largely due to their higher abundance and their larger number of protein-protein interaction partners.

scholarly journals Loss-of-Function Polymorphism of the Human Kallikrein Gene with Reduced Urinary Kallikrein Activity

2002 ◽  
Vol 13 (4) ◽  
pp. 968-976 ◽  
Author(s):  
Rola Slim ◽  
Florence Torremocha ◽  
Thierry Moreau ◽  
Anne Pizard ◽  
Steven C. Hunt ◽  
...  
Keyword(s):  
Vascular Diseases ◽  
Allelic Frequency ◽  
The Other ◽  
Nucleotide Polymorphisms ◽  
Urinary Kallikrein ◽  
Loss Of Function ◽  
Kinin System ◽  
Molecular Variants ◽  
Kallikrein Kinin System ◽  
Kallikrein Activity

ABSTRACT. Kallikrein is synthesized in the distal tubules and produces kinins, which are involved in the regulation of vascular tone in the kidney. Urinary kallikrein activity has been reported to be partly inherited and to be reduced in essential hypertension. In a systematic search for molecular variants of the human kallikrein gene, nine single-nucleotide polymorphisms were identified. Five of those polymorphisms, including two nonsynonymous substitutions in exon 3, i.e., Arg53His (allelic frequency in Caucasian subjects, 0.03) and Gln121Glu (allelic frequency, 0.33), were studied in a normotensive group and two independent hypertensive groups for which 24-h urinary kallikrein activity had been measured. A significant decrease in urinary kallikrein activity was observed for the subjects who were heterozygous for the Arg53His polymorphism, compared with the other subjects. This finding was consistent in the two hypertensive groups and was observed with several kallikrein enzymatic assays. The Gln121Glu polymorphism and the other polymorphisms were not associated with changes in urinary kallikrein activity. None of the polymorphisms was associated with hypertension. Recombinant kallikrein variants were synthesized and enzymatically characterized, using native kininogen and kininogen-derived synthetic peptide substrates. No important effect was observed after Gln121 mutation, but there was a major decrease in enzyme activity when Arg53 was replaced by histidine. A model of kallikrein derived from crystallographic data suggested that Arg53 can affect substrate binding. The identification of a subset of subjects with genetically reduced kallikrein activity as a result of an amino acid mutation could facilitate analysis of the role of the kallikrein-kinin system in renal and vascular diseases.

The DAL81 gene product is required for induced expression of two differently regulated nitrogen catabolic genes in Saccharomyces cerevisiae

1991 ◽  
Vol 11 (2) ◽  
pp. 1161-1166 ◽  
Author(s):  
P A Bricmont ◽  
J R Daugherty ◽  
T G Cooper
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Steady State ◽  
Amino Acid ◽  
The Other ◽  
Loss Of Function ◽  
Induced Expression ◽  
Catabolic Genes ◽  
Acid Protein ◽  
Steady State Levels ◽  
Amino Acid Protein

We demonstrate that the DAL81 gene, previously thought to be specifically required for induced expression of the allantoin pathway genes in Saccharomyces cerevisiae, functions in a more global manner. The data presented show it to be required for utilization of 4-aminobutyrate as a nitrogen source and for 4-aminobutyrate-induced increases in the steady-state levels of UGA1 mRNA. The DAL81 gene encodes a 970-amino-acid protein containing sequences homologous to the Zn(II)2Cys6 motif and two stretches of polyglutamine residues. Deletion of sequences homologous to the Zn(II)2Cys6 motif did not result in a detectable loss of function. On the other hand, loss of one of the polyglutamine stretches, but not the other, resulted in a 50% loss of DAL81 function.

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