scholarly journals Clasp and dance: Mating mode promotes variable sexual size and shape dimorphism trajectories in crocodile newts (Caudata: Salamandridae)

2021 ◽  
Author(s):  
Peter Pogoda ◽  
Marcus Zuber ◽  
Tilo Baumbach ◽  
Alexander Kupfer
Keyword(s):  
Model System ◽  
Cranial Morphology ◽  
Suitable Model ◽  
Evolutionary Forces ◽  
Potential Source ◽  
Long Time ◽  
Selective Forces ◽  
Sexual Shape Dimorphism ◽  
Males And Females ◽  
Intraspecific Morphological Variation

Sexual dimorphism (SD) is a main source of intraspecific morphological variation, however sexual shape dimorphism (SShD) was long time neglected in evolutionary research. Especially in cold-blooded animal groups only subtle shape differences are expressed between males and females and the selective forces behind it are poorly understood. Crocodile newts of the genera Echinotriton and Tylototriton are highly polymorphic in their reproductive ecology and hence, are a highly suitable model system to investigate potential evolutionary forces leading to SShD differences. We applied 3D geometric morphometrics to the cranial and humerus morphology of nine species of crocodile newts to investigate patterns of SShD in relation to the different mating modes. Trajectories of shape differences between males and females differ in both, cranium and humerus but mating mode does explain differences in SShD trajectories between species only in cranial morphology. Nevertheless, cranial morphology shape differed between the amplecting and circle dancing species. Hence, other selective forces must act here. Variable interspecific allometric trajectories are a potential source of shape differences whereas these trajectories are quite stable for the sexes irrespective of the species.

Ce(IV)-mediated formation of benzenediazonium ion from a non-aminoazo dye, 1-phenylazo-2-hydroxy-naphthalene (Sudan I) and its binding to DNA

1989 ◽  
Vol 54 (7) ◽  
pp. 2021-2026
Author(s):  
Marie Stiborová ◽  
Befekadu Asfaw ◽  
Pavel Anzenbacher
Keyword(s):  
Azo Dyes ◽  
Acidic Medium ◽  
Model System ◽  
Calf Thymus Dna ◽  
Suitable Model ◽  
Principal Product ◽  
Calf Thymus ◽  
Sudan I ◽  
A Minor

Ce(IV) ions in acidic medium convert a carcinogenic non-aminoazo dye, 1-phenylazo-2-hydroxy-naphthalene (Sudan I) into an ultimate carcinogen, which binds to calf thymus DNA. The principal product of Sudan I oxidation by the Ce(IV) system is the benzenediazonium ion. A minor product is the dihydroxyderivative of Sudan I, 1-(4-hydroxyphenylazo)-2,6-dihydroxynaphthalene. Other minor coloured products (yellow and brown) were not identified. The principal product (the benzenediazonium ion) is responsible for the carcinogenicity of Sudan I, as it covalently binds to DNA. Ce(IV) ions in acidic medium represent a suitable model system, which imitates the activation route of carcinogenic azo dyes.

scholarly journals Age-Related Alterations in the Behavior and Serotonin-Related Gene mRNA Levels in the Brain of Males and Females of Short-Lived Turquoise Killifish (Nothobranchius furzeri)

Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1421
Author(s):  
Valentina S. Evsiukova ◽  
Elizabeth A. Kulikova ◽  
Alexander V. Kulikov
Keyword(s):  
Locomotor Activity ◽  
Body Mass ◽  
Mrna Level ◽  
Model Organism ◽  
The Body ◽  
Suitable Model ◽  
Mrna Levels ◽  
Age Related ◽  
Nothobranchius Furzeri ◽  
Males And Females

Short-lived turquoise killifish (Nothobranchius furzeri) have become a popular model organism for neuroscience. In the present paper we study for the first time their behavior in the novel tank diving test and the levels of mRNA of various 5-HT-related genes in brains of 2-, 4- and 6-month-old males and females of N. furzeri. The marked effect of age on body mass, locomotor activity and the mRNA level of Tph1b, Tph2, Slc6a4b, Mao, Htr1aa, Htr2a, Htr3a, Htr3b, Htr4, Htr6 genes in the brains of N. furzeri males was shown. Locomotor activity and expression of the Mao gene increased, while expression of Tph1b, Tph2, Slc6a4b, Htr1aa, Htr2a, Htr3a, Htr3b, Htr4, Htr6 genes decreased in 6-month-old killifish. Significant effects of sex on body mass as well as on mRNA level of Tph1a, Tph1b, Tph2, Slc6a4b, Htr1aa, 5-HT2a, Htr3a, Htr3b, Htr4, and Htr6 genes were revealed: in general both the body mass and the expression of these genes were higher in males. N. furzeri is a suitable model with which to study the fundamental problems of age-related alterations in various mRNA levels related with the brains 5-HT system.

scholarly journals Haematological and cytogenetic changes in CML patients treated with imatinib mesylate in Western Libya

2019 ◽  
Vol 7 (3) ◽  
Author(s):  
Jbireal JM ◽  
Azab Elsayed Azab ◽  
Alzahani S ◽  
Elshareef M
Keyword(s):  
Imatinib Mesylate ◽  
White Blood Cells ◽  
Chronic Phase ◽  
Significant Negative Correlation ◽  
Cytogenetic Response ◽  
P Value ◽  
Normal Range ◽  
Long Time ◽  
Cytogenetic Changes ◽  
Males And Females

Background: Chronic myeloid leukemia (CML) is a clonal myeloid proliferative disorder of primitive haemopoietic progenitor cells. The incidence of CML ranges between 10 and 15 cases/106 /year without any major geographic or ethnic differences. Imatinib mesylate provides good results in the treatment of CML. Early studies demonstrated that Imatinib mesylate can produce clear hematologic and cytogenetic response when used as a treatment of CML patients with positive BCR-ABL gene. Nevertheless, some patient with different stages of CML (chronic, accelerated, or acute phases) either relapse or stay unchanged for a long time after initial doses of treatment. This phenomenon led to the fact that we must explore the possible changes expected to appear if we make some changes in the treatment strategy. Objectives: The present study aimed to evaluate hematologic and molecular responses of CML patients to Imatinib mesylate treatment. Methods: Eighteen CML patients in chronic phase aged (24–65 years) males and females were treated with Imatinib mesylate (400, 500 or 600 mg/day) for sixteen months. Hematologic and cytogenetic changes were analyzed periodically. Results: Overall 18 cases, hematologic response of 14 cases was complete white blood cells (WBCs) decrease to normal range within 4 months) with P value of less than 0.0001 whereas in 4 cases WBCs were decreased slowly (after 8 months). A major cytogenetic response was noticed in 4 cases while in others the response was partially or in minor range. The major hematologic and cytogenetic response was noticed when using 600mg/day of Imatinib mesylate. The correlation appeared as a significant positive correlation between the treatment doses and Hb, hematocrit, MCV, MCH, esinophils%, and monocytes %. And a significant negative correlation between the treatment doses and RDW %, platelets count, WBCs count, and basophils %. On the other hand, no correlation between the treatment doses and RBCs Count, MCHC, Neutrophil % and BCR/APL ratio % Conclusion: It can be concluded that treatment of CML patients with Imatinib mesylate caused complete WBCs decrease to normal range. The major hematologic and cytogenetic response was noticed when using a higher dose of Imatinib mesylate.

Intraspecific variation in a lizard from the Central Mexican Plateau: intersexual differences in size and shape explored

2020 ◽  
Vol 131 (3) ◽  
pp. 656-666
Author(s):  
Abraham Lozano ◽  
Aurelio Ramírez-Bautista ◽  
Raciel Cruz-Elizalde
Keyword(s):  
Body Size ◽  
Trophic Niche ◽  
Size And Shape ◽  
Biomechanical Models ◽  
Tree Population ◽  
Morphological Adaptations ◽  
Selective Forces ◽  
Sceloporus Grammicus ◽  
Intraspecific Morphological Variation ◽  
Two Populations

Abstract Morphological adaptations of individuals are directly (or indirectly) determined by the environment. Depending on sex, these adaptations may vary in different ways, given that different selective forces may be operating on organisms. Here, we evaluate intraspecific morphological variation (size and shape) in two populations of Sceloporus grammicus that occur in different structural habitats (trees and rocks). No difference in overall body size was found between the two populations. However, strong differences were found in body shape; the tree population was characterized by having shorter hindlimb proportions than the rock population, which agrees with the theory of biomechanical models. Furthermore, our results show that this species is dimorphic in size and shape, both in sex and population effects. A review of the literature suggests that the large overall body size and relatively longer distal segments of males could be an advantage for defending their territory, and the observation that females had relatively longer head length may be related to trophic niche divergence; however, this remains to be tested. Detailed quantification of behaviour, performance and reproductive characteristics must be performed to shed light on the evolution of sexual dimorphism in this widely distributed species in Mexico.

Zygnematophyceae: from living algae collections to the establishment of future models

2020 ◽  
Vol 71 (11) ◽  
pp. 3296-3304
Author(s):  
Hong Zhou ◽  
Klaus von Schwartzenberg
Keyword(s):  
Model Organism ◽  
Past Research ◽  
Model Organisms ◽  
Current Status ◽  
Future Research ◽  
Suitable Model ◽  
Research Perspectives ◽  
Robust Model ◽  
Physiological Adaptations ◽  
Long Time

Abstract The class of conjugating green algae, Zygnematophyceae (Conjugatophyceae), is extremely rich in species and has attracted the interest of phycologists for a long time. It is now widely accepted that this class of charophyte algae holds a key position in the phylogenetic tree of streptophytes, where they represent the closest relatives to all land plants (embryophytes). It is increasingly evident that robust model plants that can be easily cultivated and genetically transformed are necessary to better understand the process of terrestrialization and the related molecular, cellular, and physiological adaptations. Living algae collections play an important role, not only for phylogenomic-based taxonomy but also for screening for suitable model organisms. For this review, we screened six major public algae collections for Zygnematophyceae strains and established a cumulative list comprising 738 different taxa (including species, subspecies, varieties, and forms). From the described biodiversity with 8883 registered taxa (AlgaeBase) the cultured Zygnematophyceae taxa worldwide cover only ~8.3%. We review the past research on this clade of algae and discuss it from the perspective of establishing a model organism. We present data on the life cycle of the genera Micrasterias and Spirogyra, representing the orders Desmidiales and Zygnematales, and outline the current status of genetic transformation of Zygnematophyceae algae and future research perspectives.

scholarly journals Forecasting for a Lagrangian aircraft campaign

2004 ◽  
Vol 4 (4) ◽  
pp. 1113-1124 ◽  
Author(s):  
A. Stohl ◽  
O. R. Cooper ◽  
R. Damoah ◽  
F. C. Fehsenfeld ◽  
C. Forster ◽  
...  
Keyword(s):  
Dispersion Model ◽  
Particle Dispersion ◽  
Model System ◽  
Suitable Model ◽  
The Novel ◽  
Model Output ◽  
Aircraft Measurement ◽  
Air Masses ◽  
Aerosol Distribution ◽  
Novel Model

Abstract. A forecast system has been developed in preparation for an upcoming aircraft measurement campaign, where the same air parcels polluted by emissions over North America shall be sampled repeatedly as they leave the continent, during transport over the Atlantic, and upon their arrival over Europe. This paper describes the model system in advance of the campaign, in order to make the flight planners familiar with the novel model output. The aim of a Lagrangian strategy is to infer changes in the chemical composition and aerosol distribution occurring en route by measured upwind/downwind differences. However, guiding aircraft repeatedly into the same polluted air parcels requires careful forecasting, for which no suitable model system exists to date. This paper describes a procedure using both Eulerian-type (i.e. concentration fields) and Lagrangian-type (i.e. trajectories) model output from the Lagrangian particle dispersion model FLEXPART to predict the best opportunities for a Lagrangian experiment. The best opportunities are defined as being highly polluted air parcels which receive little or no emission input after the first measurement, which experience relatively little mixing, and which are reachable by as many aircraft as possible. For validation the system was applied to the period of the NARE 97 campaign where approximately the same air masses were sampled on different flights. Measured upwind/downwind differences in carbon monoxide (CO) and ozone (O3) decreased significantly as the threshold values used for accepting cases as Lagrangian were tightened. This proves that the model system can successfully identify Lagrangian opportunities.

scholarly journals Agarose beads as matrices for proteins in cytophotometric investigations of immunohistoperoxidase procedures;.

1975 ◽  
Vol 23 (4) ◽  
pp. 243-250 ◽  
Author(s):  
J G Streefkerk ◽  
M van der Ploeg ◽  
P van Duijn
Keyword(s):  
Model System ◽  
Suitable Model ◽  
Protein Marker ◽  
Agarose Beads ◽  
Immunologic Reactions ◽  
Final Amount ◽  
Staining Time

Quantitative aspects of direct immunohistoperoxidase procedures were studied in a model system consisting of agarose beads to which antigens or antibodies had been coupled. It could be proven that the final amount of reaction product resulting from the histoperoxidase reaction with 3,3-diaminobenzidine-tetra HCl in a bead was linearly related to the volume of the beads and to the staining time. This implies that protein-coupled agarose beads are a suitable model for the study of stoichiometric aspects of immunologic reactions in immunohistochemistry as well as in general immunologic methods when peroxidase is used as the protein marker.

Shells of Patella aspera as ‘islands’ for epibionts

2014 ◽  
Vol 94 (5) ◽  
pp. 1027-1032 ◽  
Author(s):  
Gustavo M. Martins ◽  
João Faria ◽  
Miguel Furtado ◽  
Ana I. Neto
Keyword(s):  
Island Biogeography ◽  
Positive Relationship ◽  
New Records ◽  
Spatial Scales ◽  
Model System ◽  
Taxonomic Resolution ◽  
Suitable Model ◽  
Multiple Spatial Scales ◽  
Fouling Organisms ◽  
The Relationship

In this study we examined the epibiont assemblage on shells of the living limpet Patella aspera. Limpets were collected at two sites at each of the nine islands of the Azores, totalling 707 individuals examined. Shells were measured and all the epibiota identified to the lowest taxonomic resolution possible. 190 taxa were recorded, of which 97% were algae, including 17 new records for the Azores. Only five shells were devoid of fouling organisms. The assemblage was dominated by a few algal taxa, whereas the majority of species occurred on less than 10% of the shells. A significant and positive relationship was generally found between basibiont size (shell length) and epibiota richness. The strength (slope) of the relationship, however, varied between islands and sites. These results suggest that a range of processes operating at multiple spatial scales influenced epibiont assemblages. Many features identified in these assemblages resemble, in many ways, those examined in island biogeography, suggesting that basibionts may be considered as ‘islands’ and may provide a suitable model system to test ecological hypotheses about ecosystems that are not so amenable to experimentation.

scholarly journals The Use of GC-, Codon-, and Amino Acid-frequencies to Understand the Evolutionary Forces at a Genomic Scale

2019 ◽  
Author(s):  
Arne Elofsson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Selective Pressure ◽  
Amino Acid Level ◽  
Gc Content ◽  
Frequency Variation ◽  
Evolutionary Forces ◽  
Charged Amino Acids ◽  
Plausible Model ◽  
Selective Forces

1AbstractIt is well known that the GC content varies enormously between organisms; this is believed to be caused by a combination of mutational preferences and selective pressure. Within coding regions, the variation of GC is more substantial in position three and smaller in position one and two. Less well known is that this variation also has an enormous impact on the frequency of amino acids as their codons vary in GC content. For instance, the fraction of alanines in different proteomes varies from 1.1% to 16.5%. In general, the frequency of different amino acids correlates strongly with the number of codons, the GC content of these codons and the genomic GC contents. However, there are clear and systematic deviations from the expected frequencies. Some amino acids are more frequent than expected by chance, while others are less frequent. A plausible model to explain this is that there exist two different selective forces acting on the genes; First, there exists a force acting to maintain the overall GC level and secondly there exists a selective force acting on the amino acid level. Here, we use the divergence in amino acid frequency from what is expected by the GC content to analyze the selective pressure acting on codon frequencies in the three kingdoms of life. We find four major selective forces; First, the frequency of serine is lower than expected in all genomes, but most in prokaryotes. Secondly, there exist a selective pressure acting to balance positively and negatively charged amino acids, which results in a reduction of arginine and negatively charged amino acids. This results in a reduction of arginine and all the negatively charged amino acids. Thirdly, the frequency of the hydrophobic residues encoded by a T in the second codon position does not change with GC. Their frequency is lower in eukaryotes than in prokaryotes. Finally, some amino acids with unique properties, such as proline glycine and proline, are limited in their frequency variation.

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