Chaos in the Bay: Odd Phenomenon Amongst Shellfish

  Seafood, or specifically shellfish, is popular worldwide. When these delicacies living populations starts dwindling, concerns may arise. Especially when this happened to clams (soft-shell) in both the Chesapeake and Maine Bays in the 1970s and researchers could not find the cause. Not until now. Dr. Metzger and his team of researchers found that the cause is a form of cancer which is not only unstable but also contagious. Similar occurrences have been affecting other species of shellfish (cockles, mussels, etc.) as well. These cells go through unorthodox changes (which would normally destroy the cell) and survive anyway. 

  This isn't isolated from only shellfish either, this is also found in certain mammals (Tasmanian Devil and Dogs). The big question is, what if this happens to humans? The Tasmanian Devils are an endangered species because of it, but dogs' immune systems can destroy the cells with ease. Now we are facing an unknown that may be scary but at the same time, it opens a whole new door. Dr. Metzger expresses that this could be a way to uncover secrets about cancer which could help other animals and people as well. A potential breakthrough in medical technology would be astounding and may save numerous lives one day.

Links:

-    https://www.nytimes.com/2023/10/02/science/contagious-cancer-shellfish-dna.html

-    https://www.nature.com/articles/s43018-023-00643-7

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New Species of Clam Found in Michigan River

A new invasive clam was found in the Illinois River, about 80 miles west of the Michigan River. This new rn aside species brings a lot of questions to mind regarding how exactly it got to the United States of America. Research indicates the species to be in the genus Corbicula, descending from Vancouver and making its way to North America by Asian immigrants. The clams themselves remained a vital source of food for those traveling to America, but the new discovery does not see to be a good one. For starters exact identification is tricky because the sexual reproduction of these clams can start from just a single clam, as a clam can self fertilize itself if it has both male and female sex organs. These clams are also capable of mating with clams within the same taxa, not just species. Another problem this clam brings is a change to the current ecosystem in which it resides. It provides a challenge to other species of clams, even a recently federal endangered species, as they share the same nutrients and food supply. It is marvelous that this one clam species has made its way thousands of miles for new habitation, but undoubtedly it reals havoc on current and future ecosystems in this area and across the nations coast.

Original Article

Don't eat them raw if at all, deadly bacteria!!!

Clam Cancer

According to the article Clam Caner Rips Along Atlantic Coast a fatal leukemia that is massacring soft-shell clam populations in the Atlantic may be caused by a contagious cancer cell line, according to results published on April 9th in Cell. Stephen Goff of Columbia University in NY compared leukemic and healthy hemocytes, finding that clam cancer cells isolate from various locations along the East Coast shared mitochondrial DNA (mtDNA) and other genetic features indicating a common origin.

Clams with this cancer show an over growth of abnormally shaped hemocytes, which convert clear circulatory fluid (healthy) to a milky white color (not healthy). infected species die within weeks or months; neoplasia is one of several factors that can wipe out entire beds of clams.

Last year, Goff and his colleagues identified a retrotransposon, called Steamer, which correlated with the disease. Normal Hemocytes contain 2-10 copies of this sequence, but cancerous carried 150-300 copies.

Researchers also found a common single-nucleotide polymorphism (SNPs) in the mtDNA of leukemic cells that were not detected in healthy clam genomes. This was proven true by microsatellites of leukemic cells were identical across samples from all the geographic locations tested. This suggests that this form of clam leukemia may have originated from a single cancer cell, and then spread throughout populations along the coast.

Goff suggested that environmental contaminants or infectious agents may trigger the cancer. Boettger added that further work is needed to confirm whether these cancer cells are truly transmissible among clams. Because clams remain sessile throughout their adult lives, suggesting that the cancer has an unusual way of transmitting.
I found this article to be very interesting, but it left me with more questions than answers. For instance, would we be able to obtain this form of cancer if we eat a cancerous clam? Have other animals been infected? It stayed vague is many sections with no clear answer 

Clam Cancer Outbreak, Spread by One Set of Cells

       
          There are currently three known cancers in nature. It is shocking that the third cancer known in nature occurred in clams. For the last 40 years, there have been leukemia-like disease outbreaks that have been depleting soft-shell clam populations along the United State's East cost. These outbreaks cause a significantly lowered harvest populations and job loss. The disease's cause and how it spread were unknown. It was speculated that the cause was from environmental factors, and it was spread by a virus. Researchers analyzed the cancer cell sequences and discovered that the cancer cells from different locations were the same. In one clam, they found that original cancer cell left its host and spread to another clam population. Cancers occur in an animal due to metastasis. Normally cancer cells have the same genes as the animal or person suffering from cancer, but it was found that none of the cancer cells had DNA matching the clams they were in. Instead, the cancer cells were the same as one another with the same DNA. It can be concluded that they all came from one original case of cancer in one clam. The cancer cells were being transmitted, not the virus. In water, the cancer cells can only live a few hours; however, this is more than enough time to infect other clams. Cancers normally do not spread in the same way as the clam since the cancer cell must leave the host, live long enough to enter another, and then it must still overcome the immune system's foreign rejection process. This cancer process may explain how cancers spread within the body from one organ to another.
           There is warning to stop eating clams or swimming since the human immune system would block the cancer cells from clams. I thought this article was pretty unique. I never thought about cancer occurring in animals. This case is interesting, and it could also correlate to the process of cancer cells transferring in the human body since it travels through the water to get to the clam. My only is question is how come the other clam does not reject the cancer cell, but humans would reject the clam's cancer cell?

Original Link: Link1
Supplemental Link: Link2