Towards understanding paternal extragenic contributions to early amphibian pattern specification: the axolotl ts—1 gene as a model system

Development ◽  
1985 ◽  
Vol 89 (Supplement) ◽  
pp. 53-68
Author(s):  
George M. Malacinski ◽  
Dorothy Barone
Keyword(s):  
Genetic Data ◽  
Mutant Gene ◽  
Model System ◽  
Early Embryogenesis ◽  
Ambystoma Mexicanum ◽  
Parental Effects ◽  
Phenotypic Data ◽  
Modes Of Action ◽  
Pattern Specification ◽  
Made In

As a model system for understanding the role sperm extragenic components might play in early embryogenesis the genetics and phenotype of the ts—1 axolotl (Ambystoma mexicanum) mutant gene are reviewed. That mutant gene displays parental effects. It exhibits both maternal (egg-mediated) as well as paternal (sperm-mediated) phenotypic effects. A variety of possible modes of action of the ts—1 gene are reviewed. Comparisons of various precedents to the ts—1 genetic data are made. In addition, novel models which account for the ts—1 phenotypic data are presented.

The influence of lithium on the competence of the ectoderm in Ambystoma mexicanum

Development ◽  
1964 ◽  
Vol 12 (2) ◽  
pp. 317-331
Author(s):  
D. O. E. Gebhardt ◽  
P. D. Nieuwkoop
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Ambystoma Mexicanum ◽  
The Other ◽  
Direct Influence ◽  
Amphibian Embryos ◽  
The Central Nervous System ◽  
The Subject ◽  
Morphogenetic Potential ◽  
Made In

The influence of lithium on the amphibian egg has been the subject of a number of investigations. From the work of Lehmann (1937), Töndury (1938), and Pasteels (1945) it is known that exposure of amphibian embryos to lithium results in a progressive cranio-caudal reduction of the central nervous system and a simultaneous conversion of the presumptive notochord into somites. Whereas these experiments were made with whole embryos, attempts have been made in recent years to localize the lithium effect by transplanting or explanting specific parts of the embryo. Gallera (1949), for instance, concluded from his experiments with transplants containing lithium treated presumptive chorda mesoderm, that lithium had reduced the ‘morphogenetic potential’ of this inductor. Lombard (1952), on the other hand, claimed that the susceptibility of amphibian eggs towards lithium was the result of the ion's direct influence on the ectoderm rather than on the presumptive archenteron roof.

scholarly journals Información mecanística en la evaluación de riesgos. Una aproximación desde las explicaciones basadas en mecanismos

2013 ◽  
Author(s):  
Juan B. Bengoetxea ◽  
José L. Luján ◽  
Oliver Todt
Keyword(s):  
Risk Assessment ◽  
Assessment Model ◽  
Philosophical Analysis ◽  
Risk Assessment Model ◽  
Information Risk ◽  
Mechanistic Explanations ◽  
Modes Of Action ◽  
Made In

RESUMENDesde la década pasada, en la evaluación de riesgos se ha propuesto utilizar la información mecanística con un doble propósito: seleccionar guías de inferencia y realizar extrapolaciones inter-químicas para establecer categorías de tóxicos. En este trabajo se utilizan aportaciones procedentes del análisis filosófico de las explicaciones mecanísticas para analizar el concepto de información mecanística utilizado en la evaluación de riesgos. Categorizamos la información mecanística de los modos de acción en términos de explicaciones etiológicas que emplean bosquejos de mecanismos. El grado de detalle que ha de incorporar la información mecanística en la evaluación de riesgos dependerá, entre otros factores, de consideraciones pragmáticas respecto del uso posterior de dicha información.PALABRAS CLAVEINFORMACIÓN MECANÍSTICA, EVAVALUACIÓN DE RIESGOS, MODELO, BOSQUEJO, EXPLICACIÓN.ABSTRACTSince the 2000s, in risk assessment studies it is usual to use mechanistic information with a double aim: to select inference guidelines and to make inter-chemical extrapolations to categorize toxics. Here, we use the contributions made in philosophical analysis of mechanistic explanations to analyze the concept of mechanistic information used in the risk assessment. We classify mechanistic information, specifically that concerning modes of action, in terms of etiological explanations employing sketches of mechanisms. The grade of the details that mechanistic information must incorporate to risk assessment depends on, among other factors, pragmatic considerations on the further use of such information.KEYWORDSMECHANISTIC INFORMATION, RISK ASSESSMENT, MODEL, SKETCH, EXPLANATION.

scholarly journals Clinical and Neurobiological Aspects of TAO Kinase Family in Neurodevelopmental Disorders

2021 ◽  
Vol 14 ◽  
Author(s):  
Chun Hu ◽  
Pan Feng ◽  
Qian Yang ◽  
Lin Xiao
Keyword(s):  
Neurodevelopmental Disorders ◽  
Basic Research ◽  
Genetic Data ◽  
Review Article ◽  
Biological Processes ◽  
Behavioral Impairment ◽  
Clinical Investigations ◽  
Substantial Progress ◽  
Biochemical Analyses ◽  
Made In

Despite the complexity of neurodevelopmental disorders (NDDs), from their genotype to phenotype, in the last few decades substantial progress has been made in understanding their pathophysiology. Recent accumulating evidence shows the relevance of genetic variants in thousand and one (TAO) kinases as major contributors to several NDDs. Although it is well-known that TAO kinases are a highly conserved family of STE20 kinase and play important roles in multiple biological processes, the emerging roles of TAO kinases in neurodevelopment and NDDs have yet to be intensively discussed. In this review article, we summarize the potential roles of the TAO kinases based on structural and biochemical analyses, present the genetic data from clinical investigations, and assess the mechanistic link between the mutations of TAO kinases, neuropathology, and behavioral impairment in NDDs. We then offer potential perspectives from basic research to clinical therapies, which may contribute to fully understanding how TAO kinases are involved in NDDs.

Experimental studies on a mutant gene (p) causing premature death of Ambystoma mexicanum embryos

Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 139-149
Author(s):  
Thomas M. Trottier ◽  
John B. Armstrong
Keyword(s):  
Muscle Development ◽  
Experimental Studies ◽  
Circulatory System ◽  
Premature Death ◽  
Mutant Gene ◽  
Ambystoma Mexicanum ◽  
Recessive Lethal ◽  
Homozygous Condition ◽  
General Defect ◽  
Superficial Tissue

The premature death (p) mutation is a recessive lethal, which, in the homozygous condition, gives rise to a complex of abnormalities. The mutant embryos develop only to stage 37, at which time disintegration of superficial tissue begins. Many of the abnormalities observed in sections of the stage-37 mutant embryo are related to its failure to establish a functioning circulatory system, or to the resulting edema and/or ascites that distend the abdomen and flanks. There are, however, abnormalities of heart, liver, gill and muscle development which cannot be attributed to lack of circulation and edema. All of these abnormalities can be indirectly related to the endoderm, particularly the anterior and dorsal endoderm. The findings, therefore, suggest that the mutation leads to a fairly general defect of the endoderm.

Lessons from Worm Dendritic Patterning

2019 ◽  
Vol 42 (1) ◽  
pp. 365-383 ◽  
Author(s):  
Sharon Inberg ◽  
Anna Meledin ◽  
Veronika Kravtsov ◽  
Yael Iosilevskii ◽  
Meital Oren-Suissa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Light And Electron Microscopy ◽  
Dendritic Tree ◽  
Model System ◽  
Model Organisms ◽  
Structural Units ◽  
The Past ◽  
Structural And Functional Properties ◽  
Made In

The structural and functional properties of neurons have intrigued scientists since the pioneering work of Santiago Ramón y Cajal. Since then, emerging cutting-edge technologies, including light and electron microscopy, electrophysiology, biochemistry, optogenetics, and molecular biology, have dramatically increased our understanding of dendritic properties. This advancement was also facilitated by the establishment of different animal model organisms, from flies to mammals. Here we describe the emerging model system of a Caenorhabditis elegans polymodal neuron named PVD, whose dendritic tree follows a stereotypical structure characterized by repeating candelabra-like structural units. In the past decade, progress has been made in understanding PVD's functions, morphogenesis, regeneration, and aging, yet many questions still remain.

scholarly journals The sites of synthesis of the principal thylakoid membrane polypeptides in Chlamydomonas reinhardtii.

1977 ◽  
Vol 74 (2) ◽  
pp. 441-452 ◽  
Author(s):  
N H Chua ◽  
N W Gillham
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Thylakoid Membrane ◽  
Sodium Dodecyl ◽  
Genetic Data ◽  
Reaction Centers ◽  
Wild Type ◽  
Improved Method ◽  
Photosystems I And Ii ◽  
Gradient Gel Electrophoresis ◽  
Made In

The sites of synthesis of the major thylakoid membrane polypeptides have been studied in the green alga Chlamydomonas reinhardtii by pulse labeling of cells with [14C]acetate in the presence of inhibitors specific for chloroplast and cytoplasmic protein synthesis. The labeled membrane polypeptides were separated by an improved method of sodium dodecyl sulfate (SDS) gradient gel electrophoresis, and autoradiographs were made of the dried gels. The results demonstrate that of the 33 polypeptides resolved in the gels, at least nine are made on chloroplast ribosomes. Two of these (polypeptides 2 and 6) are associated with the reaction centers of photosystems I and II. Another polypeptide (polypeptide 5) appears from genetic data to be coded by chloroplast DNA. Experiments with a mutant whose chloroplast ribosomes are resistant to spectinomycyn (spr-u-1-6-2) show that polypeptides whose synthesis takes place on chloroplast ribosomes are made in the presence of spectinomycin in the mutant although their synthesis is blocked by this antibiotic in wild type cells.

scholarly journals An integrated model system to gain mechanistic insights into biofilm formation and antimicrobial resistance development in Pseudomonas aeruginosa MPAO1

2020 ◽  
Author(s):  
Adithi R. Varadarajan ◽  
Raymond N. Allan ◽  
Jules D. P. Valentin ◽  
Olga E. Castañeda Ocampo ◽  
Vincent Somerville ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Soft Lithography ◽  
Flow Chamber ◽  
Model System ◽  
Secretion Systems ◽  
Phenotypic Data ◽  
Biofilm Growth ◽  
Mutant Collection

AbstractPseudomonas aeruginosa MPAO1 is the parental strain of the widely utilized transposon mutant collection for this important clinical pathogen. Here, we validate a model system to identify genes involved in biofilm growth and antibiotic resistance.Our model employs a genomics-driven workflow to assemble the complete MPAO1 genome, identify unique and conserved genes by comparative genomics with the PAO1 reference strain and missed genes by proteogenomics. Among over 200 unique MPAO1 genes, we identified six general essential genes that were overlooked when mapping public Tn-seq datasets against PAO1, including an antitoxin. Genomic data were integrated with phenotypic data from an experimental workflow using a user-friendly, soft lithography-based microfluidic flow chamber for biofilm growth. Experiments conducted across three laboratories delivered reproducible data on P. aeruginosa biofilms and validated both known and novel genes involved in biofilm growth and antibiotic resistance identified in screens of the mutant collection. Differential protein expression data from planktonic cells versus biofilm confirmed upregulation of candidates known to affect biofilm formation, of structural and secreted proteins of type six secretion systems, and provided proteogenomic evidence for some missed MPAO1 genes. This integrated, broadly applicable model promises to improve the mechanistic understanding of biofilm formation, antimicrobial tolerance and resistance evolution.

scholarly journals Indirect parental effects on offspring viability by egg-derived fluids in an external fertilizer

2020 ◽  
Vol 287 (1940) ◽  
pp. 20202538
Author(s):  
Rowan A. Lymbery ◽  
Jacob D. Berson ◽  
Jonathan P. Evans
Keyword(s):  
Evolutionary Biology ◽  
Mytilus Galloprovincialis ◽  
Fertilization Rate ◽  
Model System ◽  
Parental Effects ◽  
Major Area ◽  
Offspring Fitness ◽  
Gamete Interactions ◽  
Males And Females ◽  
Nongenetic Inheritance

The capacity for parents to influence offspring phenotypes via nongenetic inheritance is currently a major area of focus in evolutionary biology. Intriguing recent evidence suggests that sexual interactions among males and females, both before and during mating, are important mediators of such effects. Sexual interactions typically extend beyond gamete release, involving both sperm and eggs, and their associated fluids. However, the potential for gamete-level interactions to induce nongenetic parental effects remains under-investigated. Here, we test for such effects using an emerging model system for studying gamete interactions, the external fertilizer Mytilus galloprovincialis . We employed a split-ejaculate design to test whether exposing sperm to egg-derived chemicals (ECs) from a female would affect fertilization rate and offspring viability when those sperm were used to fertilize a different female's eggs. We found separate, significant effects of ECs from non-fertilizing females on both fertilization rate and offspring viability. The offspring viability effect indicates that EC-driven interactions can have nongenetic implications for offspring fitness independent of the genotypes inherited by those offspring. These findings provide a rare test of indirect parental effects driven exclusively by gamete-level interactions, and to our knowledge the first evidence that such effects occur via the gametic fluids of females.

scholarly journals Ecological-evolutionary relationships in Passiflora alata from Rio Grande do Sul, Brazil

2006 ◽  
Vol 66 (3) ◽  
pp. 809-816 ◽  
Author(s):  
P. Koehler-Santos ◽  
A. P. Lorenz-Lemke ◽  
F. M. Salzano ◽  
L. B. Freitas
Keyword(s):  
Geographical Distribution ◽  
Molecular Genetic ◽  
Rio Grande ◽  
Genetic Data ◽  
Evolutionary Relationships ◽  
Rio Grande Do Sul ◽  
First Report ◽  
Ecological Characteristics ◽  
Molecular Genetic Data ◽  
Made In

The geographical distribution, ecological characteristics, flowering and fruiting times, and pollinating agents of Passiflora alata are considered and related to molecular genetic data gathered simultaneously. The first report on this species in Rio Grande do Sul was made in 1934, only in cultivated gardens. Approximately 20 years later, however, the species was already classified as efferata (wild) in Porto Alegre's suburbs. The data presented here, together with the DNA investigations, indicate that P. alata is actively colonizing previously unoccupied areas of this region.

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