Golden apple snail may give insight on human eye regeneration

    Researchers studied the Golden apple snail which has eyes similar to cameras. It has structures like lens, retina and cornea similar to human eyes. These snails are resilient and very invasive in lots of parts of the world. Its regeneration ability is important to research because their eyes are so similar to human eyes. They found that when the snails' eye is removed it takes about a month to fully regenerate. This includes reconnecting to the brain and restoring vision, that part takes a little longer than a few months. 

    The regeneration process happens in phases. Wound healing, which is the first 24 hours, then unspecialized cells migrate, proliferate, and specialize into eye tissues. Over a few weeks the new eyes mature and then become useable. 

      In relation to humans the PAX6 gene, which is crucial for eye development is also essential in these snails, Using CRISPR-Cas9 the PAX6 gene was disabled in snail embryos. When both copies were inactive snails developed without eyes to show how important this gene is. 

    These snails are important to study and do research on because they share key genes with humans. They could be used as a model organism to study eye regeneration. The next steps in research they're taking are to test whether PAX6 also plays a role in regenerating the eye not just in the eye's initial development. The goal is to map out the snail's regeneration program then relates it to human eyes to see if regeneration is at all possible.

    Sources: 

Saey, T. H. (2025, August 6). This snail may hold a secret to human eye regeneration. Science News. https://www.sciencenews.org/article/snail-human-eye-regeneration

This Snail’s Eyes Grow Back: Could They Help Humans do the Same? (2025, August 14). UC Davis. https://www.ucdavis.edu/news/snails-eyes-grow-back-could-they-help-humans-do-same

  

The World's First Crispr Snail Babies

As it turns out, a large majority of snails are righties. When I say righties, I mean that most snails have shells that coil to the right. Lefties are so rare in the snail world that a couple years ago, there was a story about a garden snail named Jeremy who originally could not find a mate because he was a lefty. He became famous for his rare trait, so scientists reached out to the world to find more lefties. One was found in England while another was found in Spain. Scientists brought the two to Jeremy so he could mate with them, but unfortunately the two snails mated with each other instead of Jeremy. Poor Jeremy! Snails are hermaphrodites and can be simultaneously male and female. Amazingly, more lefties were found, so Jeremy was able to find a lefty mate right before he died. Interestingly enough, all of his children were right-coilers which means that even though Jeremy is dead, his kids are all right.

Fast-forward two years, and researchers have finally identified the gene responsible for shell direction in snails. Snails who have both working copies of Lsdia1 will be traditional right-coilers. On the other hand, snails with only have Lsdia2 will be left-coilers like Jeremy. To confirm their findings, they were able to use Crispr to edit out Lsdia1 while leaving behind Lsdia2. Just as expected, the snails were born lefties and so were their babies.

Jeremy (second to last) with his friends Senda, Jara, Tomeau, and Indi.

The research presented by the researchers, Reiko Kuroda and Masanori Abe, is really telling of the future to come concerning left and right symmetry in organisms. Chirality is something that is almost universal among species. Exploring the body plans of animals is hidden in their genetic codes, and it is remarkable of how little is known on the subject of leftiness and why it is a rarity in nature. For instance, situs inversus, a condition where human internal organs are flipped affects only about 1 in 10,000 people. People with this condition are as healthy as people with traditionally-flipped organs, so why is it such a rarity? The researchers believe the answer may lie in snails, since situs inversus is similar to left-coiling in snails. Snail research turns out to have some exciting news, but I imagine the work is rather slow.

Links to Sources:
https://www.nytimes.com/2019/05/24/science/snails-lefties-crispr.html?rref=collection%2Ftimestopic%2FGenetic%20Engineering
https://www.npr.org/sections/thetwo-way/2017/10/13/557652159/jeremy-the-lonely-left-twisting-snail-dies-but-knows-love-before-the-end

It's Easy to Be Fearless When You Have a Good Shell

Johan Ahlgren, a researcher at Lund University in Sweden, created a personality test using snails. He would gather a bunch of baby snails from different ponds and raise them until their adulthood. He gently prodded the snails' shells with tweezer to scare them and monitered how long it took for the snail to come back out of its shell. The results that came back was that bold snails came from under their shell in less than 10 seconds and shy shells came from under their shell in more than 15 seconds. He was interested in the trait "boldness" and found out that bold snails also tend to have rounder shells with wider openings and shy snails tend to have elongated shells with narrower openings. 

Could the shape of the snail's shell be related to the environment it grows up in? The snails used in Ahlgren's experiment were used in a lab, so it is assumed that the trait "boldness" could possibly be genetic. The scientists in the article defined this as "the ghost of predation past" because the predator on that snail has left its mark on the snail's DNA. So, those snails who inherit the "shy" trait cannot help but stay inside their shell for a long period of time because it is naturally within them. 

"Wow! I never would have thought a snail's shell had anything to do with their boldness. What if a shell that is bold turns shy because something tragic happens? Would their offspring inherit their shy trait or bold trait? I also wonder if the weight of a snails' shell has anything to do with how slow a snail moves. Or maybe snails are just slow in general and there is no snail that is quicker than the other. That is another topic to discuss, but this article really intrigues me."   

Click Here for more of the article!

What Extroverts and Introverts Can Learn from Snails

Researchers at the Lund University in Sweden are taking a closer look into the personalities of snails.  In most species, it can be seen that some individuals act more bold and aggressive, while others seem to be more shy, and this is no different in snails.  To test the snails’ personalities, lead researcher Johan Ahlgren would tap the snails’ shells until they hid inside.  Those snails who would reemerge in ten seconds and under were classified as bold while those who took over fifteen seconds to reemerged were classified as shy.  

The interesting part of this study looks into shell thickness.  The bold snails always had thicker shells than the shy snails.  The thick-shelled snails, can be more behavior this way because of the extra protection their shells offer them.  Meanwhile, the thin-shelled snails have to be more cautious of predators, and other dangerous situations, because they are less protected.

This is where genetics plays a huge role.  The thickness of a snail’s shell is an observable characteristic, a phenotype, which means it has corresponding genes that code for it.  These snails inherited their shell thickness genes from their parents, which produced the phenotype of either thick or thin shells.  The most amazing part of this is that these genes affected the snails personalities and level of cautiousness.  

I find this to be extremely interesting because this gives insight into the age old question of nature versus nurture.  This is a debate of whether genes or environment make a person who they are, and it has been debated for hundreds of years.  This experiment definitely does not end the debate, but it shows a great case for the nature side.  These snails were all taken from the same pond, and were fed the same diet, which according to the nurture theory would make them all equal, but this clearly was not the case.  The genes these snails had for shell thickness affected their personalities, showing genetics goes deeper than just physical traits.

Original Article

For more information on the genetics of introverts and extroverts click here.

How the Genes of One Species of Snail Can Fight Against Schitosomisis

A group of genes that has been recently discovered by researchers at Oregon State University in a particular species of snail has been found to provide a natural resistance to the flatworm parasite that causes schistosomiasis. Schistosomiasis--also know as bilharzia--is a devastating parasitic disease cause by flatworms that affects more than 200 million people worldwide; however, it was originally native to Africa. The disease can cause chronic, lifelong disability that begins with gastrointestinal problems, of which can lead to liver damage, kidney failure, infertility, and bladder cancer. It is also considered one of the Neglected Tropical Diseases (NTDs) since not many are aware of the large impact schistosomiasis has despite the fact that it is second to malaria as the most devastating parasitic disease.

The parasites that cause this disease live in certain types of snails.  The infectious form of the parasite emerges from the snail and thus, contaminates the water people use. It is for this reason that researchers have begun studying snails to further understand the transmission cycle of the disease. As it turns out, researchers have discovered a new class of genes in a species of snails that appears to be responsible for controlling the ability to resist schistosomiasis. They found that the dominant form of the genetic allele in this region reveals an eight-fold decrease in the risk of schistosomiasis.

These genes were found to be the type to help recognize pathogens and trigger an immune response--with further research, the exact genetics will be better understood. Nonetheless, this new discovery has now opened doors for efforts in treating or controlling schistosomiasis. Using this new information, the development of a new drug could be used to prevent the disease or scientists may attempt to inject the parasite-resistant genes into snails that are not resistant to schistosomiasis--this method, however, is less practical. Although there is still much research and experimentation that must be completed first, this discovery has been critical in opening pathways for new potential treatments to control and prevent this highly debilitating disease.

Original Article: click here.
About Schistosomiasis: click here.