Sentences with word «cavefish»
Researchers have described a new genus and species of cavefish from Mexico — the Oaxaca Cave Sleeper.
sciencedaily.com
Non-mammalian animals like zebrafish, fruit flies, nematode worms and even seemingly more exotic creatures like salamanders and Mexican blind cavefish provide powerful experimental models for understanding fundamental biology and disease mechanisms.
«First sleeper goby cavefish in Western Hemisphere.»
The eyeless cavefish Astyanas mexicanus is «a special system in which we can look at evolution in action,» says article co-author William Jeffery, a senior adjunct scientist at the Marine Biological Laboratory (MBL) in Woods Hole, Mass., and a professor at the University of Maryland.
«In other cavefish species, barbels are also equipped with chemosensors to help them identify food in sediment, so these fish will need to be further studied to figure these mechanisms out.»
Since cavefish aren't a well - studied model for human metabolism, the researchers had to figure out protocols as they went, including developing a fish version of a glucose tolerance test.
In the new study, the researchers poked around to see whether other aspects of cavefish metabolism were abnormal.
«Despite high blood sugar, cavefish live long, healthy lives.»
«I hope people get excited about cavefish as a model when they see that we can provide insight into phenomena even as well - studied as insulin resistance,» said Aspiras.
The fat, eyeless cavefish harbor the same genetic mutation as people with an inherited form of severe diabetes and experience diabetes - like blood - sugar surges and crashes after eating, yet they are perfectly healthy, according to a study in Nature led by geneticists at Harvard Medical School.
«Blind cavefish offer evidence for alternative mechanism of evolutionary change.»
«Through comparison of their appearance and genetics with surface fish caught upstream and downstream from the cave, we found evidence that the first European cavefish population is indeed a distinct lineage, with its own adaptations,» she says.
Most known cavefish are found in North America and China, and until now none had been seen in Europe.
A remote underground cave system in Germany has yielded a ghost - like cavefish that evolved as recently as 16,000 years ago
«In Slovenia's Dinaric karst, there are no true cavefish, just surface species that occasionally make it down,» says Janez Mulec of the Karst Research Institute in Postojna, Slovenia.
«With the German cavefish discovery, our understanding of underground ecosystems is becoming more complex, indicating that there are often enough nutrients to sustain complex food chains.»
«The barbels are enlarged in what seems to be a possible adaption to tactile sensing in the dark,» says Roi Holzman of Tel Aviv University in Israel, who studies how cavefish navigate.
Many genes govern the development of eyes, and different populations of cavefish have lost their vision by disrupting different eye genes.
Actually, it seems that it wasn't really much of a marriage to begin How do fish with normal eyes in well - lit surface - water environments transform into blind cavefish, and should this loss of structures and functionality
The fact that these eyeless cavefish are so young makes them very attractive to understand evolutionary processes at their beginning.»
2) «Over the course of evolutionary history, snakes have lost legs, cavefish have lost vision, and parasitic bacterium have lost the ability to live independently in the wild, all in an effort to become better adapted to their environments.»
Instead the cavefish «see» by sucking.
Like many species that live in perpetual darkness, the blind cavefish has lost its eyes.
But Aniket Gore of the US's National Institute of Child Health and Human Development and colleagues haven't found any disabling changes in the DNA sequences of eye development genes in the cavefish.
The discovery that a cavefish might have lost its sight because key eye genes were switched off via epigenetics, rather than mutation, will fuel an evolutionary debate
The researchers propose that this epigenetic mechanism allowed the cavefish to shed its eyes faster than if the change had happened via DNA mutations in eye genes.
We've found out why a Mexican cavefish has no eyes — and the surprising answer is likely to be seized upon by those who think the standard view of evolution needs revising.
This is the embryo of a cavefish at the age of five days.
This gene is important in development and has been implicated in other animals losing their sight, such as the Mexican blind cavefish.
Experiments revealed that the cavefish also have constantly elevated blood sugar but don't appear to suffer the consequences people do, such as nerve and blood - vessel damage.
They found that hybrids with the cavefish mutation weighed more and had higher blood - sugar levels than those without the mutation.
The researchers then bred the cavefish with the surface fish and studied hundreds of the resulting hybrids.
Going a step further, the researchers transplanted the cavefish mutation into zebrafish and confirmed that it contributes to both insulin resistance and weight gain.
Tabin and colleagues previously revealed that the cavefish have mutations in the same gene as people with insatiable appetites.
«The cavefish have high blood sugar, but no sugarcoated proteins.
The study «raises the exciting possibility» that the cavefish have other mutations that protect against the usual harms of poor blood - sugar regulation, said co-senior author Tabin, the George Jacob and Jacqueline Hazel Leder Professor of Genetics and head of the Department of Genetics at HMS.
They compared three different populations of cavefish with their surface - dwelling, metabolically normal cousins and found that the cavefish enjoy equally long lives despite their insulin resistance.
Using the cavefish, the team demonstrated for the first time in nature how «standing» or «cryptic» genetic variations in an animal, which have been inherited from prior generations without causing any physical changes in the animal, can be «unmasked» by the shock of entering a new environment.
The environmental shock that prompted the loss of eyes in the cavefish, the scientists propose, occurred about 2 or 3 million years ago when its surface - dwelling ancestors, which have eyes, «either colonized these caves or were trapped in them,» Jeffery says.
In the case of the cavefish, the present study finds, HSP90 inhibition due to environmental shock unmasked cryptic genetic variations, allowing smaller or bigger eyes to be expressed in different individuals.
They found the cavefish do store more visceral fat than their riverine relatives.
To test that idea, Tabin and his team compared the cavefish with river fish raised under identical conditions in the lab.
The cavefish's eyes are about 10 per cent smaller than those of surface loaches, and their barbels are longer.
«We would always have expected that cavefish should occur in the cave hotspots in Europe — there is no real reason why not,» says Jörg Freyhof at the Leibniz - Institute of Freshwater Ecology and Inland Fisheries in Berlin
But discovering the cavefish in Germany was a surprise, says Behrmann - Godel, because cave systems are far richer in life further south in the Balkans, where hundreds of subterranean species including weird «baby dragon» salamanders have been discovered — but no cavefish so far.
A CAVE diver in Germany has discovered Europe's first cavefish.
A team of researchers from Harvard Medical School and Whitehead Institute report that, at least in the case of one variety of cavefish, one agent of evolutionary change is the heat shock protein known as HSP90.
In a study conducted by Tel Aviv University researchers and published last month in the Journal of Experimental Biology, the team observed a previously unknown mechanism by which Astyanax fasciatus, known colloquially as the Mexican blind cavefish, uses suction waves to create vibrations in the water around it and then measures its distance to nearby objects by detecting changes to water pressure on its skin.