Cavefish
نویسنده
چکیده
What are cavefish? Like other cave-dwelling animals, fish that live in caves have often lost their eyes and body colour, but the evolutionary mechanisms underlying these reductions are unknown. There are 86 species of cavefish that belong to 18 different families, and many of them have lost their eyes independently. Comparing cavefish to their free-living ancestors can thus help us understand convergent evolution. However, the ancestors of most cave species are already extinct, with the notable exception of the Mexican Blind Cavefish.
منابع مشابه
Restoring eye size in Astyanax mexicanus blind cavefish embryos through modulation of the Shh and Fgf8 forebrain organising centres.
The cavefish morph of the Mexican tetra (Astyanax mexicanus) is blind at adult stage, although an eye that includes a retina and a lens develops during embryogenesis. There are, however, two major defects in cavefish eye development. One is lens apoptosis, a phenomenon that is indirectly linked to the expansion of ventral midline sonic hedgehog (Shh) expression during gastrulation and that indu...
متن کاملShadow response in the blind cavefish Astyanax reveals conservation of a functional pineal eye.
The blind cavefish Astyanax mexicanus undergoes bilateral eye degeneration during embryonic development. Despite the absence of light in the cave environment, cavefish have retained a structurally intact pineal eye. We show here that contrary to visual degeneration in the bilateral eyes, the cavefish pineal eye has conserved the ability to detect light. Larvae of two different Astyanax cavefish...
متن کاملCranial asymmetry arises later in the life history of the blind Mexican cavefish, Astyanax mexicanus
As a consequence of adaptation to the cave environment, the blind Mexican cavefish, Astyanax mexicanus, has evolved several cranial aberrations including changes to bone sizes, shapes and presence of numerous lateral asymmetries. Prior studies of cranial asymmetry in cavefish focused strictly on adult specimens. Thus, the extent to which these asymmetries emerge in adulthood, or earlier in the ...
متن کاملTo see or not to see: evolution of eye degeneration in mexican blind cavefish.
The evolutionary mechanisms responsible for the loss of eyes in cave animals are still unresolved. Hypotheses invoking natural selection or neutral mutation have been advanced to explain eye regression. Here we describe comparative molecular and developmental studies in the teleost Astyanax mexicanus that shed new light on this problem. A. mexicanus is a single species consisting of a sighted s...
متن کاملDe Novo Sequencing of Astyanax mexicanus Surface Fish and Pachón Cavefish Transcriptomes Reveals Enrichment of Mutations in Cavefish Putative Eye Genes
Astyanax mexicanus, a teleost species with surface dwelling (surface fish) and cave adapted (cavefish) morphs, is an important model system in evolutionary developmental biology (evodevo). Astyanax cavefish differ from surface fish in numerous traits, including the enhancement of non-visual sensory systems, and the loss of eyes and pigmentation. The genetic bases for these differences are not f...
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عنوان ژورنال:
- Current Biology
دوره 14 شماره
صفحات -
تاریخ انتشار 2004