scholarly journals Inter-species comparison of the orientation algorithm directing larval chemotaxis in the genus Drosophila

2021 ◽  
Author(s):  
Elie Fink ◽  
Matthieu Louis
Keyword(s):  
Neural Circuits ◽  
Rapid Evolution ◽  
Structure And Function ◽  
Olfactory Behavior ◽  
Species Comparison ◽  
Closely Related Species ◽  
Genetic Studies ◽  
Phenotypic Differences ◽  
Peripheral Olfactory System ◽  
And Function

Animals differ in their appearances and behaviors. While many genetic studies have addressed the origins of phenotypic differences between fly species, we are still lacking a quantitative assessment of the variability in the way different fly species behave. We tackled this question in one of the most robust behaviors displayed by Drosophila: chemotaxis. At the larval stage, Drosophila melanogaster navigate odor gradients by combining four sensorimotor routines in a multilayered algorithm: a modulation of the overall locomotor speed and turn rate; a bias in turning during down-gradient motion; a bias in turning toward the gradient; the local curl of trajectories toward the gradient ("weathervaning"). Using high-resolution tracking and behavioral quantification, we characterized the olfactory behavior of eight closely related species of the Drosophila group in response to 19 ecologically-relevant odors. Significant changes are observed in the receptive field of each species, which is consistent with the rapid evolution of the peripheral olfactory system. Our results reveal substantial inter-species variability in the algorithms directing larval chemotaxis. While the basic sensorimotor routines are shared, their parametric arrangements can vary dramatically across species. The present analysis sets the stage for deciphering the evolutionary relationships between the structure and function of neural circuits directing orientation behaviors in Drosophila.

scholarly journals How Can Satellite DNA Divergence Cause Reproductive Isolation? Let Us Count the Chromosomal Ways

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Patrick M. Ferree ◽  
Satyaki Prasad
Keyword(s):  
Reproductive Isolation ◽  
Developmental Stages ◽  
Rapid Evolution ◽  
Model Organisms ◽  
Cellular Mechanisms ◽  
Closely Related Species ◽  
Heterochromatin Formation ◽  
Interspecies Hybrids ◽  
Postzygotic Reproductive Isolation ◽  
And Function

Satellites are one of the most enigmatic parts of the eukaryotic genome. These highly repetitive, noncoding sequences make up as much as half or more of the genomic content and are known to play essential roles in chromosome segregation during meiosis and mitosis, yet they evolve rapidly between closely related species. Research over the last several decades has revealed that satellite divergence can serve as a formidable reproductive barrier between sibling species. Here we highlight several key studies on Drosophila and other model organisms demonstrating deleterious effects of satellites and their rapid evolution on the structure and function of chromosomes in interspecies hybrids. These studies demonstrate that satellites can impact chromosomes at a number of different developmental stages and through distinct cellular mechanisms, including heterochromatin formation. These findings have important implications for how loci that cause postzygotic reproductive isolation are viewed.

scholarly journals The unique features of glycolytic pathways in Archaea

2003 ◽  
Vol 375 (2) ◽  
pp. 231-246 ◽  
Author(s):  
Corné H. VERHEES ◽  
Servé W. M. KENGEN ◽  
Judith E. TUININGA ◽  
Gerrit J. SCHUT ◽  
Michael W. W. ADAMS ◽  
...  
Keyword(s):  
Functional Genomics ◽  
Convergent Evolution ◽  
Structure And Function ◽  
Glycolytic Enzymes ◽  
Genetic Studies ◽  
Phylogenetic Lineages ◽  
And Function

An early divergence in evolution has resulted in two prokaryotic domains, the Bacteria and the Archaea. Whereas the central metabolic routes of bacteria and eukaryotes are generally well-conserved, variant pathways have developed in Archaea involving several novel enzymes with a distinct control. A spectacular example of convergent evolution concerns the glucose-degrading pathways of saccharolytic archaea. The identification, characterization and comparison of the glycolytic enzymes of a variety of phylogenetic lineages have revealed a mosaic of canonical and novel enzymes in the archaeal variants of the Embden–Meyerhof and the Entner–Doudoroff pathways. By means of integrating results from biochemical and genetic studies with recently obtained comparative and functional genomics data, the structure and function of the archaeal glycolytic routes, the participating enzymes and their regulation are re-evaluated.

scholarly journals Comprehensive in silico Analysis of IKBKAP gene that could potentially cause Familial dysautonomia

2018 ◽  
Author(s):  
Mujahed I. Mustafa ◽  
Enas A. Osman ◽  
Abdelrahman H. Abdelmoneiom ◽  
Dania M. Hassn ◽  
Hadeel M. Yousif ◽  
...  
Keyword(s):  
In Silico ◽  
Genetic Disorder ◽  
In Silico Analysis ◽  
Familial Dysautonomia ◽  
Structural Effect ◽  
Structure And Function ◽  
Genetic Studies ◽  
And Function ◽  
Silico Analysis

AbstractBackgroundFamilial dysautonomia (FD) is a rare neurodevelopmental genetic disorder within the larger classification of hereditary sensory and autonomic neuropathies. We aimed to identify the pathogenic SNPs in IKBKAP gene by computational analysis software’s, and to determine the structure, function and regulation of their respective proteins.Materials and MethodsWe carried out in silico analysis of structural effect of each SNP using different bioinformatics tools to predict SNPs influence on protein structure and function.Result41 novel mutations out of 973 nsSNPs that are found be deleterious effect on the IKBKAP structure and function.ConclusionThis is the first in silico analysis in IKBKAP gene to prioritize SNPs for further genetic studies.

scholarly journals Learning the architectural features that predict functional similarity of neural networks

2020 ◽  
Author(s):  
Adam Haber ◽  
Elad Schneidman
Keyword(s):  
Neural Networks ◽  
Architectural Design ◽  
Neural Circuits ◽  
High Accuracy ◽  
Structure And Function ◽  
Functional Similarity ◽  
Architectural Features ◽  
Wide Range ◽  
And Function ◽  
Sparse Set

ABSTRACTThe mapping of the wiring diagrams of neural circuits promises to allow us to link structure and function of neural networks. Current approaches to analyzing connectomes rely mainly on graph-theoretical tools, but these may downplay the complex nonlinear dynamics of single neurons and networks, and the way networks respond to their inputs. Here, we measure the functional similarity of simulated networks of neurons, by quantifying the similitude of their spiking patterns in response to the same stimuli. We find that common graph theory metrics convey little information about the similarity of networks’ responses. Instead, we learn a functional metric between networks based on their synaptic differences, and show that it accurately predicts the similarity of novel networks, for a wide range of stimuli. We then show that a sparse set of architectural features - the sum of synaptic inputs that each neuron receives and the sum of each neuron’s synaptic outputs - predicts the functional similarity of networks of up to 100 cells, with high accuracy. We thus suggest new architectural design principles that shape the function of neural networks, which conform with experimental evidence of homeostatic mechanisms.

Cloning, Sequencing, and Expression of the Amelogenin Gene in Two Scincid Lizards

2006 ◽  
Vol 85 (2) ◽  
pp. 138-143 ◽  
Author(s):  
S. Delgado ◽  
M.-L. Couble ◽  
H. Magloire ◽  
J.-Y. Sire
Keyword(s):  
Rapid Evolution ◽  
Structure And Function ◽  
Enamel Matrix ◽  
Conserved Residues ◽  
Gene Coding ◽  
Enamel Structure ◽  
Enamel Protein ◽  
Sequencing And Expression ◽  
And Function

Our knowledge of the gene coding for amelogenin, the major enamel protein, is mainly based on mammalian sequences. Only two sequences are available in reptiles. To know whether the snake sequence is representative of the amelogenin condition in squamates, we have studied amelogenin in two scincid lizards. Lizard amelogenin possesses numerous conserved residues in the N- and C-terminal regions, but its central region is highly variable, even when compared with the snake sequence. This rapid evolution rate indicates that a single squamate sequence was not representative, and that comparative studies of reptilian amelogenins might be useful to detect the residues which are really important for amelogenin structure and function. Reptilian and mammalian enamel structure is roughly similar, but no data support amelogenin being similarly expressed during amelogenesis. By performing in situ hybridization using a specific probe, we showed that lizard ameloblasts express amelogenin as described during mammalian amelogenesis. However, we have not found amelogenin transcripts in odontoblasts. This indicates that full-length amelogenin is specific to enamel matrix, at least in this lizard.

Cognitive Neuroscience of Dyslexia

2018 ◽  
Vol 49 (4) ◽  
pp. 798-809 ◽  
Author(s):  
Anila M. D'Mello ◽  
John D. E. Gabrieli
Keyword(s):  
Reading Instruction ◽  
Cognitive Neuroscience ◽  
Brain Function ◽  
Neural Circuits ◽  
Brain Plasticity ◽  
Structure And Function ◽  
Functional Brain ◽  
Diagnosis And Prognosis ◽  
And Function ◽  
White Matter Connectivity

Purpose This review summarizes what is known about the structural and functional brain bases of dyslexia. Method We review the current literature on structural and functional brain differences in dyslexia. This includes evidence about differences in gray matter anatomy, white matter connectivity, and functional activations in response to print and language. We also summarize findings concerning brain plasticity in response to interventions. Results We highlight evidence relating brain function and structure to instructional issues such as diagnosis and prognosis. We also highlight evidence about brain differences in early childhood, before formal reading instruction in school, which supports the importance of early identification and intervention. Conclusion Neuroimaging studies of dyslexia reveal how the disorder is related to differences in structure and function in multiple neural circuits.

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