Novel Husbandry Practices Result in Rapid Rates of Growth and Sexual Maturation Without Impacting Adult Behavior in the Blind Mexican Cavefish

Zebrafish, Journal Year: 2023, Volume and Issue: 20(2), P. 86 - 94

Published: April 1, 2023

Animal model systems are dependent on the standardization of husbandry protocols that maximize growth and reduce generation time. The Mexican tetra, Astyanax mexicanus, exists as eyed surface blind cave dwelling populations. opportunity for comparative approaches between independently evolved populations has led to rapid A. mexicanus a evolution biomedical research. However, slow inconsistent rate remains major limitation expanded application mexicanus. Fortunately, this temporal can be addressed through changes accelerate rates while maintaining optimal health outcomes. Here, we describe protocol produces in diet, feeding frequency, sorting progressive tank size. This produced robust decreased age sexual maturity comparison our previous protocol. To determine whether impacted behavior, tested fish exploration schooling assays. We found no difference behavior two groups, suggesting increased will not impact natural variation behavioral traits. Taken together, standardized development genetic model.

Language: Английский

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Automated behavioral profiling using neural networks reveals differences in stress-like behavior between cave and surface-dwelling Astyanax mexicanus

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 5, 2025

Abstract Behavioral stress responses allow animals to quickly adapt local environments and are critical for survival. Stress provide an ideal model investigating the evolution of complex behaviors due their conservation across species, role in survival, integration behavioral physiological components. The Mexican cavefish ( Astyanax mexicanus ) has evolved dramatically different compared river-dwelling surface fish morphs, providing a investigate neural evolutionary basis stress-like responses. Surface morphs inhabit predator-rich whereas cave-dwelling occupy predator-free habitats. While these key ecological variables may underlie differences responses, complexity not been thoroughly examined. By leveraging automated pose-tracking machine learning tools, we quantified range associated with stress, including freezing, bottom-dwelling, hyperactivity, during novel tank assay. exhibited heightened characterized by prolonged bottom-dwelling frequent while demonstrated reduced behaviors, marked greater exploration minimal freezing. Analysis F2 hybrids revealed that subset freezing co-segregated, suggesting shared genetic or underpinnings. Our findings illustrate power computational tools high-throughput phenotyping, enabling precise quantification traits revealing factors driving evolution. This study provides framework understanding how integrated evolve, offering broader insights into mechanisms underlying diversification animal behavior natural systems.

Language: Английский

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Trait Loss in Evolution: What Cavefish Have Taught Us about Mechanisms Underlying Eye Regression

Integrative and Comparative Biology, Journal Year: 2023, Volume and Issue: 63(2), P. 393 - 406

Published: May 22, 2023

Synopsis Reduction or complete loss of traits is a common occurrence throughout evolutionary history. In spite this, numerous questions remain about why and how trait has occurred. Cave animals are an excellent system in which these can be answered, as multiple traits, including eyes pigmentation, have been repeatedly reduced lost across populations cave species. This review focuses on the blind Mexican cavefish, Astyanax mexicanus, used model for examining developmental, genetic, mechanisms that underlie eye regression animals. We focus aspects evolved A. developmental genetic pathways contribute to regression, effects evolution other also forces contributing regression. discuss what known repeated both mexicanus cavefish more generally. Finally, we offer perspectives future further elucidate underlying using tools resources recently become available.

Language: Английский

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A brain-wide analysis maps structural evolution to distinct anatomical module

eLife, Journal Year: 2023, Volume and Issue: 12

Published: July 27, 2023

The vertebrate brain is highly conserved topologically, but less known about neuroanatomical variation between individual regions. Neuroanatomical at the regional level hypothesized to provide functional expansion, building upon ancestral anatomy needed for basic functions. Classically, animal models used study evolution have lacked tools detailed anatomical analysis that are widely in zebrafish and mice, presenting a barrier studying fine scales. In this study, we sought investigate of using single species fish consisting divergent surface cave morphs, permits genetic testing volume shape across entire brain. We generated high-resolution atlas blind Mexican cavefish Astyanax mexicanus coupled with automated computational directly assess variability region all populations. measured every grossly defined assessed correlations regions fish, cavefish, × F 2 hybrids, whose phenotypes span range cave. find dorsal contracted, while ventral expanded, hybrid data providing support developmental constraint along dorsal-ventral axis. Furthermore, these relationships show similar patterns both shape, suggesting captured by two parameters could be driven mechanisms. Together, demonstrate A. powerful system functionally determining principles will permit how genes influence early patterning events drive brain-wide evolution.

Language: Английский

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Sensing in the dark: Constructive evolution of the lateral line system in blind populations of Astyanax mexicanus

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(4)

Published: April 1, 2024

Abstract Cave‐adapted animals evolve a suite of regressive and constructive traits that allow survival in the dark. Most studies aiming at understanding cave animal evolution have focused on genetics environmental underpinnings traits, with special emphasis vision loss. Possibly as result loss, other non‐visual sensory systems expanded compensated species. For instance, many cave‐dwelling fish species, including blind cavefish Mexican tetra, Astyanax mexicanus , major mechanosensory system called lateral line, for loss through morphological expansions. While substantial work has shed light adaptation this system, there are still open questions regarding its developmental origin, synaptic plasticity, overall adaptive value. This review provides snapshot current state knowledge line adaption A. an anatomy, behavior. Multiple avenues future research how these can be leveraged tools both evolutionary biology medicine, discussed.

Language: Английский

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Host evolution shapes gut microbiome composition in Astyanax mexicanus

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(4)

Published: April 1, 2024

The ecological and genetic changes that underlie the evolution of host-microbe interactions remain elusive, primarily due to challenges in disentangling variables alter microbiome composition. To understand impact host habitat, genetics, evolutionary history on microbial community structure, we examined gut microbiomes river- three cave-adapted morphotypes Mexican tetra,

Language: Английский

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Mutations in the albinism gene oca2 alter vision-dependent prey capture behavior in the Mexican tetra

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: June 20, 2024

Abstract Understanding the phenotypic consequences of naturally occurring genetic changes, as well their impact on fitness, is fundamental to understanding how organisms adapt an environment. This critical when variants have pleiotropic effects, determining each phenotype impacted by a gene contributes fitness essential understand and why traits evolved. A striking example contributing trait evolution oca2 gene, coding mutations in which underlie albinism reductions sleep blind Mexican cavefish, Astyanax mexicanus . Here, we characterize effects larval prey capture. We find that conspecific surface fish with engineered allele are hunting, they use cave-like, wide angle strikes capture prey. However, unlike cavefish or dark, rely lateral line mediated mutant vision at from angles. Finally, while do not outcompete pigmented siblings albino light. raises possibility detrimental feeding surface-like lighted environment, but does negative for dark environments. Together, these results demonstrate plays role behavior A. Further, expand our evolution.

Language: Английский

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The Mexican Tetra, Astyanax mexicanus, as a Model System in Cell and Developmental Biology

Annual Review of Cell and Developmental Biology, Journal Year: 2023, Volume and Issue: 39(1), P. 23 - 44

Published: July 12, 2023

Our understanding of cell and developmental biology has been greatly aided by a focus on small number model organisms. However, we are now in an era where techniques to investigate gene function can be applied across phyla, allowing scientists explore the diversity flexibility mechanisms gain deeper life. Researchers comparing eyeless cave-adapted Mexican tetra, Astyanax mexicanus, with its river-dwelling counterpart revealing how development eyes, pigment, brain, cranium, blood, digestive system evolves as animals adapt new environments. Breakthroughs our genetic basis regressive constructive trait evolution have come from A. mexicanus research. They include types mutations that alter traits, which cellular processes they affect, lead pleiotropy. We review recent progress field highlight areas for future investigations sex differentiation, neural crest development, metabolic regulation embryogenesis.

Language: Английский

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