Embryonic head involution and rotation of male terminalia require the Drosophila locus head involution defective.

Abstract We have characterized the head involution defective (hid) locus which is located within the chromosomal region 75B8-C1,2. During the morphogenetic reorganization of the embryonic head region, hid+ function is necessary for the movement of the dorsal fold across the procephalon and clypeolabrum, a process that forms the frontal sac. The absence of the frontal sac in the hid mutant embryos affects the formation of the dorsal bridge and disrupts the development of the larval cephalopharyngeal skeleton. In addition to its embryonic role, this same hid function is also required during pupal development for the 360 degrees rotation of the male terminalia about the anterior-posterior body axis, and for a late step of wing blade morphogenesis. Although the abnormal wing phenotype caused by the Wrinkled (W) mutation is quite different from the one resulting from the loss-of-function hid mutations, the characterization of EMS-induced W revertants reveals that W is actually an antimorphic allele of hid.

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A screen for modifiers of Deformed function in Drosophila.

Genetics ◽

10.1093/genetics/140.4.1339 ◽

1995 ◽

Vol 140 (4) ◽

pp. 1339-1352 ◽

Cited By ~ 8

Author(s):

K W Harding ◽

G Gellon ◽

N McGinnis ◽

W McGinnis

Keyword(s):

Signalling Pathways ◽

Homeotic Genes ◽

Loss Of Function ◽

The Third ◽

Head Development ◽

Complementation Groups ◽

Embryonic Head ◽

Anterior Posterior ◽

Anterior Posterior Axis

Abstract Proteins produced by the homeotic genes of the Hox family assign different identifies to cells on the anterior/posterior axis. Relatively little is known about the signalling pathways that modulate their activities or the factors with which they interact to assign specific segmental identifies. To identify genes that might encode such functions, we performed a screen for second site mutations that reduce the viability of animals carrying hypomorphic mutant alleles of the Drosophila homeotic locus, Deformed. Genes mapping to six complementation groups on the third chromosome were isolated as modifiers of Deformed function. Products of two of these genes, sallimus and moira, have been previously proposed as homeotic activators since they suppress the dominant adult phenotype of Polycomb mutants. Mutations in hedgehog, which encodes secreted signalling proteins, were also isolated as Deformed loss-of-function enhancers. Hedgehog mutant alleles also suppress the Polycomb phenotype. Mutations were also isolated in a few genes that interact with Deformed but not with Polycomb, indicating that the screen identified genes that are not general homeotic activators. Two of these genes, cap 'n' collar and defaced, have defects in embryonic head development that are similar to defects seen in loss of function Deformed mutants.

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par-6, a gene involved in the establishment of asymmetry in early C. elegans embryos, mediates the asymmetric localization of PAR-3

Development ◽

10.1242/dev.122.10.3133 ◽

1996 ◽

Vol 122 (10) ◽

pp. 3133-3140 ◽

Cited By ~ 15

Author(s):

J.L. Watts ◽

B. Etemad-Moghadam ◽

S. Guo ◽

L. Boyd ◽

B.W. Draper ◽

...

Keyword(s):

Early Embryo ◽

Cell Periphery ◽

Loss Of Function ◽

P Granules ◽

C Elegans ◽

Lethal Mutations ◽

Cell Embryo ◽

New Gene ◽

The One ◽

Anterior Posterior

The generation of asymmetry in the one-cell embryo of Caenorhabditis elegans is necessary to establish the anterior-posterior axis and to ensure the proper identity of early blastomeres. Maternal-effect lethal mutations with a partitioning defective phenotype (par) have identified several genes involved in this process. We have identified a new gene, par-6, which acts in conjunction with other par genes to properly localize cytoplasmic components in the early embryo. The early phenotypes of par-6 embryos include the generation of equal-sized blastomeres, improper localization of P granules and SKN-1 protein, and abnormal second division cleavage patterns. Overall, this phenotype is very similar to that caused by mutations in a previously described gene, par-3. The probable basis for this similarity is revealed by our genetic and immunolocalization results; par-6 acts through par-3 by localizing or maintaining the PAR-3 protein at the cell periphery. In addition, we find that loss-of-function par-6 mutations act as dominant bypass suppressors of loss-of-function mutations in par-2.

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Functional Characterization of the Adenylyl Cyclase Genesgs-1by Analysis of a Mutational Spectrum inCaenorhabditis elegans

Genetics ◽

10.1093/genetics/161.1.133 ◽

2002 ◽

Vol 161 (1) ◽

pp. 133-142 ◽

Cited By ~ 4

Author(s):

Celine Moorman ◽

Ronald H A Plasterk

Keyword(s):

Life Span ◽

Adenylyl Cyclase ◽

Neuronal Degeneration ◽

Functional Characterization ◽

Adenylyl Cyclases ◽

Loss Of Function ◽

C Elegans ◽

Larval Stages ◽

Pharyngeal Pumping

AbstractThe sgs-1 (suppressor of activated Gαs) gene encodes one of the four adenylyl cyclases in the nematode C. elegans and is most similar to mammalian adenylyl cyclase type IX. We isolated a complete loss-of-function mutation in sgs-1 and found it to result in animals with retarded development that arrest in variable larval stages. sgs-1 mutant animals exhibit lethargic movement and pharyngeal pumping and (while not reaching adulthood) have a mean life span that is >50% extended compared to wild type. An extensive set of reduction-of-function mutations in sgs-1 was isolated in a screen for suppressors of a neuronal degeneration phenotype induced by the expression of a constitutively active version of the heterotrimeric Gαs subunit of C. elegans. Although most of these mutations change conserved residues within the catalytic domains of sgs-1, mutations in the less-conserved transmembrane domains are also found. The sgs-1 reduction-of-function mutants are viable and have reduced locomotion rates, but do not show defects in pharyngeal pumping or life span.

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Synthesis and Polymerization Kinetics of Rigid Tricyanate Ester

Polymers ◽

10.3390/polym13111686 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1686

Author(s):

Andrey Galukhin ◽

Roman Nosov ◽

Ilya Nikolaev ◽

Elena Melnikova ◽

Daut Islamov ◽

...

Keyword(s):

Kinetic Analysis ◽

Single Step ◽

Polymerization Kinetics ◽

Scanning Calorimetry ◽

Modulated Differential Scanning Calorimetry ◽

Diffusion Controlled ◽

Polymerization Product ◽

The One ◽

Kinetics Of

A new rigid tricyanate ester consisting of seven conjugated aromatic units is synthesized, and its structure is confirmed by X-ray analysis. This ester undergoes thermally stimulated polymerization in a liquid state. Conventional and temperature-modulated differential scanning calorimetry techniques are employed to study the polymerization kinetics. A transition of polymerization from a kinetic- to a diffusion-controlled regime is detected. Kinetic analysis is performed by combining isoconversional and model-based computations. It demonstrates that polymerization in the kinetically controlled regime of the present monomer can be described as a quasi-single-step, auto-catalytic, process. The diffusion contribution is parameterized by the Fournier model. Kinetic analysis is complemented by characterization of thermal properties of the corresponding polymerization product by means of thermogravimetric and thermomechanical analyses. Overall, the obtained experimental results are consistent with our hypothesis about the relation between the rigidity and functionality of the cyanate ester monomer, on the one hand, and its reactivity and glass transition temperature of the corresponding polymer, on the other hand.

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Interactions between the WEE-1.3 kinase and the PAM-1 aminopeptidase in oocyte maturation and the early C. elegans embryo

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkab063 ◽

2021 ◽

Author(s):

Dorothy Benton ◽

Eva C Jaeger ◽

Arielle Kilner ◽

Ashley Kimble ◽

Josh Lowry ◽

...

Keyword(s):

Missense Mutation ◽

Oocyte Maturation ◽

Protective Role ◽

C Elegans ◽

Direct Target ◽

The One ◽

Actomyosin Cytoskeleton ◽

Embryonic Viability ◽

Anterior Posterior

Abstract Puromycin-sensitive aminopeptidases are found across phyla and are known to regulate the cell-cycle and play a protective role in neurodegenerative disease. PAM-1 is a puromycin-sensitive aminopeptidase important for meiotic exit and polarity establishment in the one-cell Caenorhabditis elegans embryo. Despite conservation of this aminopeptidase, little is known about its targets during development. In order to identify novel interactors, we conducted a suppressor screen and isolated four suppressing mutations in three genes that partially rescued the maternal-effect lethality of pam-1 mutants. Suppressed strains show improved embryonic viability and polarization of the anterior-posterior axis. We identified a missense mutation in wee-1.3 in one of these suppressed strains. WEE-1.3 is an inhibitory kinase that regulates maturation promoting factor. While the missense mutation suppressed polarity phenotypes in pam-1, it does so without restoring centrosome-cortical contact or altering the cortical actomyosin cytoskeleton. To see if PAM-1 and WEE-1.3 interact in other processes, we examined oocyte maturation. While depletion of wee-1.3 causes sterility due to precocious oocyte maturation, this effect was lessened in pam-1 worms, suggesting that PAM-1 and WEE-1.3 interact in this process. Levels of WEE-1.3 were comparable between wild-type and pam-1 strains, suggesting that WEE-1.3 is not a direct target of the aminopeptidase. Thus, we have established an interaction between PAM-1 and WEE-1.3 in multiple developmental processes and have identified suppressors that are likely to further our understanding of the role of puromycin-sensitive aminopeptidases during development.

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Congruence pairs of principal MS-algebras and perfect extensions

Mathematica Slovaca ◽

10.1515/ms-2017-0430 ◽

2020 ◽

Vol 70 (6) ◽

pp. 1275-1288

Author(s):

Abd El-Mohsen Badawy ◽

Miroslav Haviar ◽

Miroslav Ploščica

Keyword(s):

Boolean Algebra ◽

Congruence Lattices ◽

Descriptive Solution ◽

The One ◽

Special Case ◽

Congruence Pair

AbstractThe notion of a congruence pair for principal MS-algebras, simpler than the one given by Beazer for K2-algebras [6], is introduced. It is proved that the congruences of the principal MS-algebras L correspond to the MS-congruence pairs on simpler substructures L°° and D(L) of L that were associated to L in [4].An analogy of a well-known Grätzer’s problem [11: Problem 57] formulated for distributive p-algebras, which asks for a characterization of the congruence lattices in terms of the congruence pairs, is presented here for the principal MS-algebras (Problem 1). Unlike a recent solution to such a problem for the principal p-algebras in [2], it is demonstrated here on the class of principal MS-algebras, that a possible solution to the problem, though not very descriptive, can be simple and elegant.As a step to a more descriptive solution of Problem 1, a special case is then considered when a principal MS-algebra L is a perfect extension of its greatest Stone subalgebra LS. It is shown that this is exactly when de Morgan subalgebra L°° of L is a perfect extension of the Boolean algebra B(L). Two examples illustrating when this special case happens and when it does not are presented.

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Insights into Mechanical Properties of the 1980 Irpinia Fault System from the Analysis of a Seismic Sequence

Geosciences ◽

10.3390/geosciences11010028 ◽

2021 ◽

Vol 11 (1) ◽

pp. 28

Author(s):

Gaetano Festa ◽

Guido Maria Adinolfi ◽

Alessandro Caruso ◽

Simona Colombelli ◽

Grazia De Landro ◽

...

Keyword(s):

Mechanical Properties ◽

Early Warning Systems ◽

Fault System ◽

Minimum Size ◽

Double Difference ◽

Warning Systems ◽

Initiation Mechanism ◽

Earthquake Early Warning Systems ◽

The One

Seismic sequences are a powerful tool to locally infer geometrical and mechanical properties of faults and fault systems. In this study, we provided detailed location and characterization of events of the 3–7 July 2020 Irpinia sequence (southern Italy) that occurred at the northern tip of the main segment that ruptured during the 1980 Irpinia earthquake. Using an autocorrelation technique, we detected more than 340 events within the sequence, with local magnitude ranging between −0.5 and 3.0. We thus provided double difference locations, source parameter estimation, and focal mechanisms determination for the largest quality events. We found that the sequence ruptured an asperity with a size of about 800 m, along a fault structure having a strike compatible with the one of the main segments of the 1980 Irpinia earthquake, and a dip of 50–55° at depth of 10.5–12 km and 60–65° at shallower depths (7.5–9 km). Low stress drop release (average of 0.64 MPa) indicates a fluid-driven initiation mechanism of the sequence. We also evaluated the performance of the earthquake early warning systems running in real-time during the sequence, retrieving a minimum size for the blind zone in the area of about 15 km.

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Mineralogical and Geochemical Characterization of Gold Mining Tailings and Their Potential to Generate Acid Mine Drainage (Minas Gerais, Brazil)

Minerals ◽

10.3390/min11010039 ◽

2020 ◽

Vol 11 (1) ◽

pp. 39

Author(s):

Mariana Lemos ◽

Teresa Valente ◽

Paula Marinho Reis ◽

Rita Fonseca ◽

Itamar Delbem ◽

...

Keyword(s):

Acid Mine Drainage ◽

Mine Drainage ◽

Minas Gerais ◽

Acid Mine ◽

Fine Grain ◽

Mineralogical Characteristics ◽

Tailing Dams ◽

The One ◽

And Control

For more than 30 years, sulfide gold ores were treated in metallurgic plants located in Nova Lima, Minas Gerais, Brazil, and accumulated in the Cocoruto tailings dam. Both flotation and leaching tailings from a deactivated circuit, as well as roasted and leaching tailings from an ongoing plant, were studied for their acid mine drainage potential and elements’ mobility. Detailed characterization of both tailings types indicates the presence of fine-grain size material hosting substantial amounts of sulfides that exhibit distinct geochemical and mineralogical characteristics. The samples from the ongoing plant show high grades of Fe in the form of oxides, cyanide, and sulfates. Differently, samples from the old circuit shave higher average concentrations of Al (0.88%), Ca (2.4%), Mg (0.96%), and Mn (0.17%), present as silicates and carbonates. These samples also show relics of preserved sulfides, such as pyrite and pyrrhotite. Concentrations of Zn, Cu, Au, and As are higher in the tailings of the ongoing circuit, while Cr and Hg stand out in the tailings of the deactivated circuit. Although the obtained results show that the sulfide wastes do not tend to generate acid mine drainage, leaching tests indicate the possibility of mobilization of toxic elements, namely As and Mn in the old circuit, and Sb, As, Fe, Ni, and Se in the tailings of the plant that still works. This work highlights the need for proper management and control of tailing dams even in alkaline drainage environments such as the one of the Cocoruto dam. Furthermore, strong knowledge of the tailings’ dynamics in terms of geochemistry and mineralogy would be pivotal to support long-term decisions on wastes management and disposal.

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Genetic and Molecular Characterization of the Caenorhabditis elegans Gene, mel-26, a Postmeiotic Negative Regulator of MEI-1, a Meiotic-Specific Spindle Component

Genetics ◽

10.1093/genetics/150.1.119 ◽

1998 ◽

Vol 150 (1) ◽

pp. 119-128

Author(s):

M Rhys Dow ◽

Paul E Mains

Keyword(s):

Caenorhabditis Elegans ◽

Protein Interactions ◽

Negative Regulator ◽

Meiotic Spindle ◽

Loss Of Function ◽

Protein Protein Interactions ◽

Gain Of Function ◽

Recessive Mutations ◽

Female Germline

Abstract We have previously described the gene mei-1, which encodes an essential component of the Caenorhabditis elegans meiotic spindle. When ectopically expressed after the completion of meiosis, mei-1 protein disrupts the function of the mitotic cleavage spindles. In this article, we describe the cloning and the further genetic characterization of mel-26, a postmeiotic negative regulator of mei-1. mel-26 was originally identified by a gain-of-function mutation. We have reverted this mutation to a loss-of-function allele, which has recessive phenotypes identical to the dominant defects of its gain-of-function parent. Both the dominant and recessive mutations of mel-26 result in mei-1 protein ectopically localized in mitotic spindles and centrosomes, leading to small and misoriented cleavage spindles. The loss-of-function mutation was used to clone mel-26 by transformation rescue. As suggested by genetic results indicating that mel-26 is required only maternally, mel-26 mRNA was expressed predominantly in the female germline. The gene encodes a protein that includes the BTB motif, which is thought to play a role in protein-protein interactions.

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Preparation and characterization of tannin-based adhesives reinforced with cellulose nanofibrils for wood bonding

Holzforschung ◽

10.1515/hf-2020-0033 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Uasmim Lira Zidanes ◽

Matheus Cordazzo Dias ◽

Mário Sérgio Lorenço ◽

Elesandra da Silva Araujo ◽

Maryella Júnnia Ferreira e Silva ◽

...

Keyword(s):

Cellulose Nanofibrils ◽

Glue Line ◽

Mechanical Resistance ◽

Thermogravimetric Analyses ◽

Humidity Resistance ◽

Wood Bonding ◽

Toona Ciliata ◽

Solids Content ◽

The One

AbstractAdhesives based on vegetable tannins are already a reality in the market. However, their use is still limited due to their low mechanical resistance and weak humidity resistance. Cellulose nanofibrils (CNFs) are being used as reinforcing materials in various composites, resulting in an improvement of mechanical proprieties in general. The objective of this work was to evaluate the incorporation of CNFs in adhesives made of tannins obtained from the Angico tree (Anadenanthera peregrine). Concentrations of nanofibrils at 1, 5, and 10% were added to the adhesives on a dry basis. Tests of viscosity, pH, solids content, and gel time were performed to determine the physical proprieties of the adhesives. The Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Raman spectra measurements were also determined to understand the interaction between tannins and CNFs. Thermogravimetric analyses (TGA) were carried out to determine the thermal resistance of the composite. The FTIR and Raman characterization identified some differences in the peaks in the chemical composition of the adhesives with different percentages of CNFs. The adhesives showed no different decomposition in the thermogravimetric analyses. The shear strength in the glue line of the adhesive with 5% of CNFs in Toona ciliata woods was determined. Among all the adhesives analyzed, the one with 5% of CNFs produced an improvement in the mechanical resistance and humidity resistance on the glue line.

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