The Sea Cucumber Genome Points to Genes for Tissue Regeneration

A new high-definition genome sequence of the sea cucumber provides molecular insights into its ability to regenerate, according to a new study publishing 12 October in the open access journal PLOS Biology by Xiaojun Zhang, Lina Sun, Hongsheng Yang and Jianhai Xiang, of the Institute of Oceanology, Chinese Academy of Sciences, and colleagues. The genome sequence also helps explain why the sea cucumber has such a radically different skeletal structure from other members of the echinoderm phylum, and may be useful for understanding evolution of the animal kingdom.

Sea cucumbers form one class of the echinoderms, a phylum that also includes sea urchins and sea stars (“star fish”). Echinoderms and chordates (a closely related phylum that includes humans) share a feature that distinguishes them from most other animals: they are so-called deuterostomes, in which the anus, rather than the mouth, forms first in development. Sea cucumbers are unique among echinoderms in not having a hardened calcium exoskeleton, and in their capacity to regenerate damaged or lost body parts and viscera to a much greater extent than sea urchins or sea stars.

To explore the genetic underpinnings of these features, and to better understand the evolution of the deuterostomes, the authors performed high-definition genomic sequencing of the sea cucumber Apostichopus japonicus (also known as the Japanese sea cucumber), covering about 92% of its estimated 880 megabases of DNA, including more than 30,000 genes.

By comparing the genome of A. japonicus with that of other organisms, the authors found evidence that the echinoderms diverged from hemichordates (a small group of marine deuterostomes that includes the acorn worms) about 533 million years ago and the sea cucumbers split off from other the echinoderm classes about 479 million years ago. The authors showed that while the sea urchin genome includes 31 genes for biomineralization, critical for forming a calcified skeleton, the sea cucumber has only seven such genes. They also found that the sea cucumber expressed these biomineralization genes at much lower levels throughout development, likely accounting for their softer bodies compared to sea urchins.

As a strategy to scare off predators, sea cucumbers can expel their viscera, which they can then regenerate within several weeks. The authors found a group of duplicated genes, called PSP94-like genes, that were specifically expressed in the regenerating intestines of the sea cucumber, which had no corresponding genes in other echinoderms, suggesting that these genes may be crucial to the animals’ ability to quickly regrow their viscera. A second group of genes, called fibrinogen-related proteins, were also duplicated and highly expressed during regeneration, indicating they likely contribute to this ability as well.

“The sea cucumber is a particularly promising model animal for regenerative medicine,” said Xiang, and the availability of its genome should aid efforts to study the biology of regeneration and determine if echinoderm regrowth can offer insights that can be applied to human medicine. “Our findings should also facilitate the understanding of the requirements for sustainable utilization and effective breeding of echinoderms, in support of the high-value sea cucumber industry,” which includes its use as a source of food and traditional Chinese medicine.

Source: Science Daily


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Sea Cucumber Used to Treat Cancer

The sea cucumber, an animal found on the ocean floor, has been used in Chinese cuisine for centuries— even as an aphrodisiac— but it’s also been known to treat a wide variety of illness, including certain types of cancer.

“They’re not only anti-viral, anti-bacterial but sea cucumbers have been used to treat gingivitis and gum disease, “ Ty M. Bollinger, author of “Cancer: Step Outside the Box,” told Fox News.

The sea animal, which resembles a large, spiky caterpillar, is used as an adjunct treatment for those undergoing chemotherapy because it’s very effective at mitigating the side effects of the cancer treatment, Bollinger said.

“Chemotherapy is an immunosuppressive set of drugs so it kills the cancer cells but in the meantime it kills your immune system… the properties of sea cucumber that are so fascinating is that it… makes [your immune system] run at the perfect speed… that’s why it’s so effective as an adjunct treatment as well as a treatment in and of itself if people decide to use sea cucumber,” he said.

Besides being immunomodulatory, sea cucumber is cytotoxic, meaning it kills cancer cells.

Sea cucumber, while long used in Traditional Chinese Medicine, is not well known in Western medicine— even though it’s been studied for the last 15 years— because most oncologists use chemotherapy, radiation, and therapy as their primary cancer treatments.

“Most people haven’t heard about anything that their doctors haven’t told them about and most doctors aren’t familiar with the sea cucumber. I’m not aware of any medical school that has courses teaching them on sea cucumbers at this point,” Bollinger said.

Sea cucumber can be cooked and eaten, as the Chinese do, or dried, made into a powder and packed into capsules to take in pill form.

“One of the fascinating things about sea cucumbers also is that it is very high in chondroitin sulfate, which you’re familiar with to treat joint pain and arthritis,” Bollinger said. “Well, sea cucumber, to my knowledge, has the highest concentration of chondroitin sulfate of any animal… it’s used very effectively for joint pain and arthritic pain.”


Watch video at You Tube (5:22 minutes) . . . . .


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Sea Cucumber 海参

Jacqueline M. Newman wrote . . . . . .

This echinoderm is related to the star fish and the sea urchin, and has, like many other plants and animals on land and in sea, many names. A more acceptable name on the European continent and in France is to call them ‘bêche de mer.’ In the United States, technocrats call them ‘trepang,’ most fishermen call them ‘sea slugs,’ and you may have heard them referred to as ‘sea rats.’ The Japanese call them namako which translates to ‘sea mice’ and some Chinese do call them ‘ginseng of the sea. Should you wonder why this Chinese name, it is because they believe they have medicinal properties, as does ginseng.

Visually, there are spiny ones and smooth ones, and they are commonly purchased dried, or prepared and soaked.

Usually found at the bottom of the sea, these are reasonably sedentary animals that protect themselves giving off a toxin, some say similar to soap. The difference is, however, this toxin can kill an animal in its vicinity. These sea creatures, when ready for consumption and also when simply soaked, are gelatinous. Alive, they tend to be found in groups, some do float on or near the water’s surface, others can be well below its surface.

Full-grown, sea cucumbers are three to ten inches long and one to two inches wide. They are scavengers that eat lots of plankton and decaying organic matter. They breathe in oxygen from the water, then expel it.

Sea cucumbers of all types are used as food in China, in the rest of Asia, and in many other countries. Aside from their culinary uses, they are used in oils and creams and in other cosmetic applications. Research about them supports their use as pain relievers, in other medications, for tissue repair, and in anti-malarial medications.

Sea cucumbers were written about in the Chinese Canon of Gastronomy in the 5th to 6th centuries CE. There, they were called hai shu. In a modern dictionary, one more commonly finds them called hai shen or hoi sam.

Not limited to Asia, hundreds of varieties of sea cucumbers swim all over the world, in both warm and cold waters. As already mentioned, they are found with a prickly exterior also called a spiny one, and with a smooth exterior; and they can be black, brown, dark tan, medium tan, and a few are actually light tan.

In the Pacific, one finds the Stichopus species of the family Holothuriodea. These and others in the Atlantic are popularly consumed at New Year celebrations. One ancient Confucian recipe, called Eight Immortals Crossing the Sea, uses them with shark’s fins, ginseng, cordyceps, and tremella. Together, the foods in this recipe are holiday wishes for longevity and disease prevention. During Confucian times, they were also known as fang ci shen or fang shen. These particular names call attention to those with a four-sided thorny exterior.

Not only popular during the Spring Festival, as the New Year holiday is also known in China and by Chinese world-wide, there is great demand for these sea animals in Asia, Europe, and elsewhere. In Atlantic waters, they are commonly known botanically as Cucumaria frondosa. All over the world, they are known for their medicinal uses, their holiday uses, and their historical uses.

Chinese, Japanese, and Russian studies report their saponin or tri-terpene glycosides have a structure similar to the active components in both ganoderma and ginseng. These structures make them loved for their anti-cancer and anti-inflammatory properties. They are also used as HIV therapy, as herpes virus inhibitors, and as long-chain sulfated polysaccharides that are chondroitin-building-block medications.

For use in the kitchen, many cooks prefer to purchase them dried while others buy theirs soaked and soft. The latter way they are mostly found in Chinese and other Asian markets. For those who do buy them dry, the recommendation is to soak them in cold water overnight, discard that water, add fresh cold water, and bring that to the boil for half an hour or more. When cooking is completed, cover them and let them cool.

The above recommendation says to repeat these two things often, sometimes needing many repetitions for as much as two to four days until they are nice and soft. When very soft, discard their intestines and any other innards, then use them in a recipe. Want to speed up this process, after one or two days of soaking, put them in fresh cold water, simmer for three hours, allow to cool, take out their innards, and touch them in many places being sure they are soft and pliable.

Before providing recipes using sea cucumbers, you might want to know that the Chinese believe they nourish one’s qi and improve one’s blood. They also tonify the kidney and reproductive organs and moisten the intestines. Traditional Chinese Medical practitioners (TCM doctors) recommend them for general weakness, to reduce frequent urination, reduce impotence, and aid general debilitation of the aged; also to increase yin and yang energy, regulate menstruation, nourish the fetus, and facilitate labor.

These TCM doctors like them used in a soup with tremella or cordyceps which will nourish yin and yang. Another recommendation is to cook them with lamb, especially from older animals, or to prepare them with pork or ham.

Sea cucumber is high in protein, has many polysaccharides, is low in fat, and helps build cartilage. For those that do not like its gelatinous texture, the only suggestion is to purchase this food/medicinal as capsules or as pills. In any form, the Chinese believe they reduce pain from arthritis even if taken in amounts as small as half teaspoon each day.

Source: Flavour and Fortune magazine