scholarly journals Reduced Oxygen as an Environmental Pressure in the Evolution of the Blind Mexican Cavefish

Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 26
Author(s):  
Tyler Boggs ◽  
Joshua Gross
Keyword(s):  
Potential Role ◽  
Environmental Changes ◽  
Environmental Stressors ◽  
Environmental Features ◽  
Extreme Phenotypes ◽  
Lower Oxygen ◽  
Surface Dwelling ◽  
Subterranean Environment ◽  
Limited Oxygen

Extreme environmental features can drive the evolution of extreme phenotypes. Over the course of evolution, certain environmental changes may be so drastic that they lead to extinction. Conversely, if an organism adapts to harsh environmental changes, the adaptations may permit expansion of a novel niche. The interaction between environmental stressors and adaptive changes is well-illustrated by the blind Mexican cavefish, Astyanaxmexicanus, which has recurrently adapted to the stark subterranean environment. The transition from terrestrial rivers and streams (occupied by extant surface morphs of the same species) to the cave has been accompanied by the resorption of eyes, diminished pigmentation and reduced metabolism in cave-dwelling morphs. The principal features of caves most often associated with evolution of these common cave features are the absence of light and limited nutrition. However, a putatively essential cave feature that has received less attention is the frequently low concentration of oxygen within natural karst environments. Here, we review the potential role of limited oxygen as a critical environmental feature of caves in the Sierra de El Abra. Additionally, we review evidence that Astyanax cavefish may have evolved adaptive features enabling them to thrive in lower oxygen compared to their surface-dwelling counterparts.

scholarly journals Comparative development and ocular histology between epigean and subterranean salamanders (Eurycea) from central Texas

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11840
Author(s):  
Ruben U. Tovar ◽  
Valentin Cantu ◽  
Brian Fremaux ◽  
Pedro Gonzalez Jr ◽  
Amanda Spikes ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Eye Morphology ◽  
Extreme Phenotypes ◽  
San Marcos ◽  
Central Texas ◽  
Surface Dwelling ◽  
Salamander Species ◽  
Barton Springs ◽  
Early Developmental ◽  
Subterranean Environment

The salamander clade Eurycea from the karst regions of central Texas provides an ideal platform for comparing divergent nervous and sensory systems since some species exhibit extreme phenotypes thought to be associated with inhabiting a subterranean environment, including highly reduced eyes, while others retain an ancestral ocular phenotype appropriate for life above ground. We describe ocular morphology, comparing three salamander species representing two phenotypes—the surface-dwelling Barton Springs salamander (E. sosorum) and San Marcos salamander (E. nana) and the obligate subterranean Texas blind salamander (E. rathbuni) - in terms of structure and size of their eyes. Eyes were examined using confocal microscopy and measurements were made using ImageJ. Statistical analysis of data was carried out using R. We also provide a developmental series and track eye development and immunolocalization of Pax6 in E. sosorum and E. rathbuni. Adult histology of the surface-dwelling San Marcos salamander (E. nana) shows similarities to E. sosorum. The eyes of adults of the epigean species E. nana and E. sosorum appear fully developed with all the histological features of a fully functional eye. In contrast, the eyes of E. rathbuni adults have fewer layers, lack lenses and other features associated with vision as has been reported previously. However, in early developmental stages eye morphology did not differ significantly between E. rathbuni and E. sosorum. Parallel development is observed between the two phenotypes in terms of morphology; however, Pax6 labeling seems to decrease in the latter stages of development in E.rathbuni. We test for immunolabeling of the visual pigment proteins opsin and rhodopsin and observe immunolocalization around photoreceptor disks in E. nana and E. sosorum, but not in the subterranean E. rathbuni. Our results from examining developing salamanders suggest a combination of underdevelopment and degeneration contribute to the reduced eyes of adult E. rathbuni.

scholarly journals CANADIAN ASSOCIATION OF NEUROSCIENCE REVIEW: Development and Plasticity of the Auditory Cortex

2003 ◽  
Vol 30 (3) ◽  
pp. 189-200 ◽  
Author(s):  
Jun Yan
Keyword(s):  
Cerebral Cortex ◽  
Auditory Cortex ◽  
Critical Period ◽  
Potential Role ◽  
Environmental Changes ◽  
Canadian Association ◽  
Developmental Feature ◽  
Functional Areas ◽  
Cholinergic Projection

ABSTRACT:The functions of the cerebral cortex are predominantly established during the critical period of development. One obvious developmental feature is its division into different functional areas that systematically represent different environmental information. This is the result of interactions between intrinsic (genetic) factors and extrinsic (environmental) factors. Following this critical period, the cerebral cortex attains its adult form but it will continue to adapt to environmental changes. Thus, the cerebral cortex is constantly adapting to the environment (plasticity) from its embryonic stages to the last minute of life. This review details important factors that contribute to the development and plasticity of the auditory cortex. The instructive role of thalamocortical innervation, the regulatory role of cholinergic projection of the basal forebrain and the potential role of the corticofugal modulation are presented.

Healthcare Facilities Settings: An overview of Environmentally-induced Stress on Health

2015 ◽  
Vol 74 (2) ◽  
Author(s):  
Tan Yu-Tian ◽  
Choong Weng-Wai ◽  
Mohd. Tajudin Hj. Ninggal
Keyword(s):  
Healing Process ◽  
Environmental Design ◽  
Environmental Stressors ◽  
Evidence Based ◽  
Healthcare Facilities ◽  
Environmental Features ◽  
Surrounding Environment ◽  
Induced Stress ◽  
Design Behaviour

The role of FM practitioners is to create an environment that sustains the primary objectives of the organisation. In managing healthcare facilities, the aim is to serve the healthcare users with efficient and quality medical environments in order to enhance the healing process. However, dysfunction that exists in environmental design is one of the issues often faced by the healthcare FM practitioners these days. Psychological stress is viewed as a consequence of design-behaviour dysfunction when the existing environmental design can no longer fit the need of users. With the possibility of certain environmental features to act as the sources of stressors, it is vital for FM practitioners to discover those features from the surrounding environment that appear to be harmful to the healthcare users. This paper provides an overview of the effect of the surrounding environment on stress. The association between environmentally induced-stress and the impacts of health is further discussed. Lastly, the application of evidence-based practice (EBP) is suggested in order to further the understanding for the association and intervention between environmental stressors and clinical outcomes. 

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

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