Background: Blindness has evolved repeatedly in cave-dwelling organisms, and many hypotheses have been proposed to explain this observation, including both accumulation of neutral loss-of-function mutations and adaptation to darkness. Investigating the loss of sight in cave dwellers presents an opportunity to understand the operation of fundamental evolutionary processes, including drift, selection, mutation, and migration.
Results: Here we model the evolution of blindness in caves. This model captures the interaction of three forces: (1) selection favoring alleles causing blindness, (2) immigration of sightedness alleles from a surface population, and (3) mutations creating blindness alleles. We investigated the dynamics of this model and determined selection-strength thresholds that result in blindness evolving in caves despite immigration of sightedness alleles from the surface. We estimate that the selection coefficient for blindness would need to be at least 0.005 (and maybe as high as 0.5) for blindness to evolve in the model cave-organism, Astyanax mexicanus.
Conclusions: Our results indicate that strong selection is required for the evolution of blindness in cave-dwelling organisms, which is consistent with recent work suggesting a high metabolic cost of eye development.
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http://dx.doi.org/10.1186/s12862-017-0876-4 | DOI Listing |
Acta Parasitol
January 2025
Cytokines and NO Synthases Team, LBCM, FSB, USTHB, BP 32 El Alia, Bab Ezzouar, Algiers, 16111, Algeria.
Purpose: Since extract of the laminated layer (LL) from E. granulosus showed immuno-modulatory effects in vitro and in vivo, we sought to determine its effect on the onset, development, and evolution of experimental auto-immune uveitis (EAU). The latter is a model of some human diseases with ocular inflammation that can cause blindness.
View Article and Find Full Text PDFFront Med (Lausanne)
January 2025
Department of Acupuncture, Qingdao Central Hospital, University of Health and Rehabilitation Sciences (Qingdao Central Hospital), Qingdao, China.
Background: Optic atrophy (OA) is primarily caused by damage to the retinal pathway system, including widespread degeneration of retinal ganglion cells and axons, leading to visual impairment and blindness. Despite its clinical significance and diverse etiological factors, there is currently a lack of comprehensive bibliometric analyses exploring research trends and hotspots within this field.
Method: This study retrieved relevant literature on OA published between 2003 and 2023 from the Web of Science Core Collection database.
medRxiv
January 2025
Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.
The U4 small nuclear RNA (snRNA) forms a duplex with the U6 snRNA and, together with U5 and ~30 proteins, is part of the U4/U6.U5 tri-snRNP complex, located at the core of the major spliceosome. Recently, recurrent variants in the U4 RNA, transcribed from the gene, and in at least two other genes were discovered to cause neurodevelopmental disorder.
View Article and Find Full Text PDFNAR Genom Bioinform
March 2025
Departments of Medicine and Pediatrics, Division of Infectious Diseases and Global Health, University of California San Francisco School of Medicine, 550 16th Street, 4th Floor Mission Hall, San Francisco, CA, 94158, USA.
Whole genome sequencing (WGS) is pivotal for the molecular characterization of ()-the leading bacterial cause of sexually transmitted infections and infectious blindness worldwide. WGS can inform epidemiologic, public health and outbreak investigations of these human-restricted pathogens. However, challenges persist in generating high-quality genomes for downstream analyses given its obligate intracellular nature and difficulty with propagation.
View Article and Find Full Text PDFJ Physiol
January 2025
Department of Ophthalmology, Stein Eye Institute, UCLA School of Medicine, Los Angeles, CA, USA.
Bipolar cells are vertebrate retinal interneurons conveying signals from rod and cone photoreceptors to amacrine and ganglion cells. Bipolar cells are found in all vertebrates and have many structural and molecular affinities with photoreceptors; they probably appeared very early during vertebrate evolution in conjunction with rod and cone progenitors. There are two types of bipolar cells, responding to central illumination with depolarization (ON) or hyperpolarization (OFF).
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