scholarly journals Shh and forebrain evolution in the blind cavefish Astyanax mexicanus

2008 ◽  
Vol 100 (3) ◽  
pp. 139-147 ◽  
Author(s):  
Sylvie Rétaux ◽  
Karen Pottin ◽  
Alessandro Alunni
Keyword(s):  
Astyanax Mexicanus ◽  
Blind Cavefish

scholarly journals Gene flow and population structure in the Mexican blind cavefish complex (Astyanax mexicanus)

2012 ◽  
Vol 12 (1) ◽  
pp. 9 ◽  
Author(s):  
Martina Bradic ◽  
Peter Beerli ◽  
Francisco J García-de León ◽  
Sarai Esquivel-Bobadilla ◽  
Richard L Borowsky
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Astyanax Mexicanus ◽  
Blind Cavefish

scholarly journals Circadian rhythms in Mexican blind cavefish Astyanax mexicanus in the lab and in the field

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Andrew Beale ◽  
Christophe Guibal ◽  
T. Katherine Tamai ◽  
Linda Klotz ◽  
Sophie Cowen ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Astyanax Mexicanus ◽  
Blind Cavefish

scholarly journals Blind cavefish retain functional connectivity in the tectum despite loss of retinal input

2021 ◽  
Author(s):  
Evan Lloyd ◽  
Brittnee McDole ◽  
Martin Privat ◽  
James B. Jaggard ◽  
Erik Duboué ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Neural Circuit ◽  
Astyanax Mexicanus ◽  
Evolutionary Selection ◽  
Environmental Perturbation ◽  
Multiple Components ◽  
Correlated Activity ◽  
Retinal Input ◽  
Hybrid Fish ◽  
Blind Cavefish

AbstractSensory systems display remarkable plasticity and are under strong evolutionary selection. The Mexican cavefish, Astyanax mexicanus, consists of eyed river-dwelling surface populations, and multiple independent cave populations which have converged on eye loss, providing the opportunity to examine the evolution of sensory circuits in response to environmental perturbation. Functional analysis across multiple transgenic populations expressing GCaMP6s showed that functional connectivity of the optic tectum largely did not differ between populations, except for the selective loss of negatively correlated activity within the cavefish tectum, suggesting positively correlated neural activity is resistant to an evolved loss of input from the retina. Further, analysis of surface-cave hybrid fish reveals that changes in the tectum are genetically distinct from those encoding eye-loss. Together, these findings uncover the independent evolution of multiple components of the visual system and establish the use of functional imaging in A. mexicanus to study neural circuit evolution.

scholarly journals Morphogenetic and patterning defects explain the coloboma phenotype of the eye in the Mexican cavefish

2019 ◽  
Author(s):  
Lucie Devos ◽  
Florent Klee ◽  
Joanne Edouard ◽  
Victor Simon ◽  
Laurent Legendre ◽  
...  
Keyword(s):  
Morphological Evolution ◽  
Developmental Defects ◽  
Optic Stalk ◽  
Astyanax Mexicanus ◽  
Cellular Processes ◽  
Tightly Coupled ◽  
Vertebrate Eye ◽  
Blind Cavefish ◽  
Epithelium Cells ◽  
Type Specification

AbstractThe morphogenesis of the vertebrate eye consists of a complex choreography of cell movements, tightly coupled to axial regionalization and cell type specification processes. Any disturbance in these events can lead to developmental defects and blindness. Here we have deciphered the sequence of defective events leading to coloboma phenotype in the embryonic eye of the blind cavefish of the species Astyanax mexicanus. Using comparative live imaging on targeted enhancer-trap Zic1:hsp70:GFP reporter lines of both the normal, river-dwelling morph and the cave morph of the species, we identified major defects in initial optic vesicle size and optic cup invagination in cavefish. Combining these results with gene expression analyses, we also discovered defects in axial patterning affecting mainly the temporal retina, in optic stalk tissue specification, and in the spreading processes involving the retinal pigmented epithelium cells. Based on these results, we propose a developmental scenario to explain the cavefish phenotype and discuss developmental constraints to morphological evolution. The cavefish eye appears as an outstanding natural mutant model to study molecular and cellular processes involved in optic region morphogenesis.

scholarly journals Social-like responses are inducible in asocial Mexican cavefish despite the exhibition of strong repetitive behavior

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Motoko Iwashita ◽  
Masato Yoshizawa
Keyword(s):  
Social Behavior ◽  
Antipsychotic Drug ◽  
Drug Targeting ◽  
Dopaminergic System ◽  
Repetitive Behavior ◽  
Astyanax Mexicanus ◽  
Social Ability ◽  
Social Species ◽  
Social Abilities ◽  
Blind Cavefish

Social behavior is a hallmark of complex animal systems; however, some species appear to have secondarily lost this social ability. In these non-social species, whether social abilities are permanently lost or suppressed is unclear. The blind cavefish Astyanax mexicanus is known to be asocial. Here, we reveal that cavefish exhibited social-like interactions in familiar environments but suppressed these interactions in stress-associated unfamiliar environments. Furthermore, the level of suppression in sociality was positively correlated with that of stereotypic repetitive behavior, as seen in mammals. Treatment with a human antipsychotic drug targeting the dopaminergic system induced social-like interactions in cavefish, even in unfamiliar environments, while reducing repetitive behavior. Overall, these results suggest that the antagonistic association between repetitive and social-like behaviors is deeply shared from teleosts through mammals.

scholarly journals Eye morphogenesis in the blind Mexican cavefish

Biology Open ◽  
2021 ◽  
Author(s):  
Lucie Devos ◽  
François Agnès ◽  
Joanne Edouard ◽  
Victor Simon ◽  
Laurent Legendre ◽  
...  
Keyword(s):  
Morphological Evolution ◽  
Developmental Defects ◽  
Cell Behaviors ◽  
Astyanax Mexicanus ◽  
Cellular Processes ◽  
Gfp Reporter ◽  
Tightly Coupled ◽  
Vertebrate Eye ◽  
Blind Cavefish ◽  
Type Specification

The morphogenesis of the vertebrate eye consists of a complex choreography of cell movements, tightly coupled to axial regionalization and cell type specification processes. Disturbances in these events can lead to developmental defects and blindness. Here, we have deciphered the sequence of defective events leading to coloboma in the embryonic eye of the blind cavefish of the species Astyanax mexicanus. Using comparative live imaging on targeted enhancer-trap Zic1:hsp70:GFP reporter lines of both the normal, river-dwelling morph and the cave morph of the species, we identified defects in migratory cell behaviors during evagination which participate in the reduced optic vesicle size in cavefish, without proliferation defect. Further, impaired optic cup invagination shifts the relative position of the lens and contributes to coloboma in cavefish. Based on these results, we propose a developmental scenario to explain the cavefish phenotype and discuss developmental constraints to morphological evolution. The cavefish eye appears as an outstanding natural mutant model to study molecular and cellular processes involved in optic region morphogenesis.

scholarly journals A Hypomorphic Cystathionine ß-Synthase Gene Contributes to Cavefish Eye Loss by Disrupting Optic Vasculature

2019 ◽  
Author(s):  
Li Ma ◽  
Aniket V. Gore ◽  
Daniel Castranova ◽  
Janet Shi ◽  
Mandy Ng ◽  
...  
Keyword(s):  
Oxygen Deficiency ◽  
Circulatory System ◽  
Astyanax Mexicanus ◽  
Transsulfuration Pathway ◽  
Key Enzyme ◽  
Surface Dwelling ◽  
Blind Cave ◽  
Different Populations ◽  
Key Indicators ◽  
Blind Cavefish

AbstractVestigial structures are key indicators of evolutionary descent but the mechanisms underlying their development are poorly understood. This study examines vestigial eye formation in the teleost Astyanax mexicanus, which consists of a sighted surface-dwelling morph and different populations of blind cave morphs. Cavefish embryos initially develop optic primordia but vestigial eyes are formed during larval development. Multiple genetic factors are involved in cavefish eye loss but none of the mutated genes have been identified. Here we identify cystathionine ß-synthase (cbsa), which encodes the key enzyme of the transsulfuration pathway, as a mutated gene responsible for eye degeneration in multiple cavefish populations. The inactivation of cbsa affects eye development by inducing accumulation of the transsulfuration intermediate homocysteine and defects in optic vasculature, including aneurysms and eye hemorrhages, leading to oxygen deficiency. Our findings suggest that localized modifications in the circulatory system and hypoxia had important roles in the evolution of vestigial eyes in blind cavefish.

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