Intestinal plasticity plays a major role in many, if not all, of the sit-and-wait predators. It is considered an adaptive alteration that helps these organisms to live and thrive with what they are given. The changes that the gut or intestines go through are supported by microbiota composition and are activated by the fatty acids in the metabolism. This adaptation is able to help maintain homeostasis and regenerate if any damage occurs while the organs undergo this process. With this, it shows that the cells are able to revert to what they were when they were needed. It can be shown in many animals, like the Burmese Python. The Burmese python, like other sit-and-wait predators, is able to go long periods of time without eating, and this is because of intestinal plasticity. During these long periods, without the consumption of food, the pythons’ gut is able to shrink to preserve energy and nutrients. When it’s time for them to eat, they eat a large amount, and their intestines are able to double in size within the day to be able to accommodate their feeding habits. Pythons are not the only species that do this, as other snakes are similar, and so are some lizards, salamanders, and frogs.

In addition to the digestive adaptation, vertebrates rely on the PTH hormone and the calcitonin hormone to maintain internal balance. These two hormones actually work together in a very different way by contradicting each other when it comes to regulating the calcium and phosphate levels in a vertebrate. When the calcium levels are low, the PTH or the parathyroid hormone works with parts of the body to increase the calcium and decrease the phosphate levels in the blood. Using bones, kidneys, and the intestines, it manages this. By sending signals to the bones, it is able to begin creating osteoclasts, which break down bone matter to release calcium. The kidneys and intestines regulate by increasing or decreasing calcium and phosphate absorption. Now, Calcitonin does the opposite because it works when the calcium is too high in the blood. It inhibits the bones from osteoclast activity, the kidneys increase calcium and phosphate exertion and the intestines have a slight decrease in absorption.

To understand the internal composition of bone and other tissues in the body, we need internal imaging. Finding elemental composition, the two main methods used are electron microscopy and EDX, or energy dispersive x-ray. Electron microscopy is using electrons to create an image instead of light. There are two main types of electron microscopy, which are SEM, which stands for scanning electron microscopy, and TEM, which stands for transmission electron microscopy. Using the SEM, you are able to create 3-D structures and, using the TEM, you can get very high-resolution images of the internal structures. The EDX can also be paired with the SEM and the TEM and this is where you are able to find the elemental compositions. These two methods help find element concentrations, like calcium in bones and metals in organelles.

Burmese pythons are massive, complex animals. Unlike many animals, they are able to swallow their prey whole. This means they eat the fur and bones and all of it, and still are able to digest it. For most animals, eating bones would be bad because of the buildup of calcium, but pythons have evolved a special way to handle this, and that is called intestinal crypts. 

When a Burmese python is fasting, these crypts become empty. This means the crypts have absolutely nothing inside them at all, not even a crumb. This makes sense because when the snake isn’t eating, no calcium or phosphorus is coming in from prey bones, so the cells don’t have anything to process. 

Things are completely different when a snake eats a normal diet. Their normal diet includes whole prey with bones, which means after consumption, the intestinal crypts are no longer empty. They fill up with multi-layered mineral particles that build up inside the cells. These particles form layers of calcium, phosphorus, and iron. These are called spheroids and are the result of the python digesting and processing the minerals that come from the skeleton of its prey. This process helps the snake get rid of extra calcium safely, and in doing so, it prevents it from staying dissolved in the blood.

When snakes are fed a boneless diet, things will end up being vastly different than if they ate prey with bones. The crypts in the intestinal cells look a lot like those in fasting snakes; they’re mostly empty. They have little to no calcium and phosphorus, but still have good quantities of iron within the crypts. This is because bones are the main source of those minerals. Since they aren’t getting the minerals they need these cells rarely form in a boneless diet. Essentially without the bones, the specialized cells don’t have a job to do. The intestines of these snakes stay quiet because there’s no extra calcium to process or excrete.

Scientists had to do tests to figure it out. In this, they had to feed the pythons with boneless diets, calcium and, it was put directly into the food. Now, because of this, the crypts are filled with large particles again, similar to the crypts of the snakes with the normal diet. That experiment showed that the formation of these calcium-phosphorus spheroids depends entirely on how much calcium the snake eats. If there’s calcium in the diet, the cells get to work.

The snake’s blood chemistry and hormones also change depending on diet. Two hormones, PTH and calcitonin, are especially important in controlling calcium balance. When blood calcium levels drop, PTH increases to bring them back up, while calcitonin usually rises when calcium levels get too high. In the study, snakes fed a low-calcium diet showed a clear drop in blood calcium levels. In response, both PTH and calcitonin levels went up, but PTH increased the most. This shows that their bodies were trying to compensate for the calcium shortage. On the other hand, snakes that end up whole prey or so-called calcium-rich meals ended up having normal calcium levels, suggesting their hormones were in balance and that the crypt cells were helping remove any extra calcium.

Researchers truly believe they have found a new cell type, which is why these and other articles were made. These cells look and act differently from other intestinal cells. Normally, intestinal cells either absorb nutrients or secrete mucus, but these cells do something different, as learned through this. They can create and excrete solid particles. Overall, yes, they made a strong case for this new cell type. Explaining the different intestinal cells and what they produce. They told how the difference in the python’s diet plays a key role in what these crypts look like and what they contain. It also shows that they are very calcium-rich, and if there is no calcium, then there is basically no crypt. These cells are very unique as they also help with balancing the calcium levels within the snake. Now these cells are not just in snakes and certain pythons. Some other bone-eating reptiles can lean towards the assumption of evolutionary adaptation

(I am unable to copy and paste my citations from the pack back assignment into this)