Calcium and phosphorus regulation in vertebrates
Homeostasis is maintained by the regulation of key compounds and ions our bodies need for survival. Calcium and phosphate are two of these key ions. Even though stored away in the skeletal system of vertebrates, ions such as Calcium and Phosphate are essential for crucial processes of bone remodeling, muscle and kidney function (Deftos L., & Shaker J, 2023). Thus, our body closely regulates these substances stored away in bones and their release into the bloodstream. Because calcium and phosphorus are key elements in homeostasis, our body closely regulates them via hormones.
The body uses negative feedback regulation to maintain a balance of Calcium and Phosphorus ions in the body. While both calcium and phosphate are found in the bone crystal hydroxyapatite, they aren’t regulated with similar endocrine pathways. Calcium is primarily regulated by the hormone PTH, vitamin D and the hormone calcitonin, to a lesser extent, (Deftos L., & Shaker J, 2023). Calcium participates in a variety of cellular transduction-pathways, thus is closely regulated by our body. Even though the average diet contains 1 mg of calcium, the concentration of extracellular calcium is close to the point in which it would precipitate and damage blood vessels (Deftos L., & Shaker J, 2023). This highlights the importance of its regulation. Additionally, phosphorus is regulated by the hormone PTH, vitamin and the hormone FGF23. Dietary phosphorus comes from most foods we ingest. Phosphorus is not regulated as closely as calcium because not only changes in lifestyles such as exercise, sleeping, and alimentation can greatly sway the body’s needs, the hormone FGF23 can promote its excretion via urine.
Intestinal Plasticity and Its Role in Ambush Predators.
Ambush redactors don’t know when they’ll get their next meal, they need to get the most out of every meal. Sit-and-wait predators, such as the Burmese Python, don’t chase prey. Instead, sit-and-wait predators hide for the perfect moment to attack. Thus, it makes sense that they require a digestive system adapted to their lifestyle.
Intestines can expand and change their shape without compromising their own functioning. Therefore, intestinal plasticity can be defined as the intestine’s ability to modify its shape to increase its digestive effectivity (J;L, 2019). As a result of the wide range in the size of the prey of the Burmese Python, an increased degree of intestinal plasticity would aid its necessity to uptake the most nutrients out of every meal. Burmese Pythons swallow their prays whole (Smithsonian, 2025). Naturally, it makes sense to conclude that Burmese Pythons would immensely benefit from an intestine capable of expanding and adapting to the body size of its prey.
Electron Microscopy, EDX analysis and The Elemental Composition Determination of Biological Samples.
An electron microscope uses the small size of the electron to magnify small objects. There are multitudes of electron microscopes. However, they all make use of the minuscule size of an electron to produce a diffraction pattern recognized by a highly sensitive camera.
EDX analysis is a commonly employed technique nowadays that makes sue of an electron scanning microscope (Nanakoudis, 2019). An Energy Dispensive X-Ray analysis uses the fact that each element has a different electron configuration. It shoots an exited electron beam into the inner shell of an atom. This produces a “hole” in the electron shell of the atom. Consequently, an electron in a higher shell will fill this hole, liberating X-rays in the process. Because these X-rays are individual to every atom, a measurement of these X-rays could also determine the atom. This technique gives accurate results, which has contributed to its widespread usage in the scientific industry.
Could intestinal Spheroids in Burmese Pythons be a new cell type?
The Burmese Python is a predator adapted to withstand drastic changes in its diet. For instance, Burmese Pythons are capable of going through long fasting periods with minimal damage to digestive organs. This is the result of its highly specialized digestive system. Characterized by a fast rate of cellular replication (Westfall et al., 2024), the intestinal lining of Burmese Pythons is capable of quickly regenerating itself. Consequently, because of the high plasticity of the digestive system, one could argue that its characteristics will also transform as the feeding habits of a snake change.
The ever-changing environment the Burmese Python is exposed to is the driving force behind its feeding habits, and intestinal characteristics. Consequently, the experiment envisioned by Jehan-Hervé Lignot aimed to represent this variability. The experiment contained snakes fed with specimens (rats) of a varying degree of calcium and phosphorus content. It ranged from fasting snakes to normal calcium and phosphorus diets, with one diet artificially emulating the calcium content of a rat via calcium carbonate enrichment.
Furthermore, due to the known high degree of plasticity in the Burmese Python digestive system, snakes in different diets exhibit different intestinal characteristics. For starters, fasting snakes “showed an atrophied intestinal epithelium” (Lignot et al., 2025). Snakes exposed to this diet exhibited small microvilli, empty and shallower crypts. Snakes normally fed exhibited long microvilli, some intestinal epithelia cells contained lipid droplets, others contained filled apical crypts with “concentric layers of acellular elements” (Lignot et al., 2025). Next, snakes on a diet low in calcium and phosphorus exhibited a moderately active intestinal environment. They exhibited long microvilli, epithelial cells with filled crypts without concentric structures and others with some lipid droplets, though less than normally fed snakes. Lastly, snakes fed with a calcium enriched diet had an intestinal epithelium similar to normally fed snakes. However, the formations surrounding the apical crypts were less concentric, and more disorganized in nature.
Hence, crypt particles have a higher chance of forming with a high calcium environment in the intestines of Burmese Pythons. As seen by the result of the experiment by Dr. Lignot and his colleagues, crypt particles largely appear in the presence of calcium within the intestinal space of snakes. Not only did crypt particles become more visible in snakes fed with normal and enriched diets, but crypt particles were also less pronounced or didn’t emerge at all in snakes fed with boneless specimen or fasting snakes, respectively (Lignot et al., 2025). As a result, it’s only natural to think these particles are made primarily of calcium and “electron-dense elements that were mostly made of iron” (Lignot et al., 2025). Consequently, crypt particles could be described as the excretory medium through which snakes avoid over-absorption of calcium during digestion.
While produced in different organs than mammals, snakes use PTH and Calcitonin hormones in a similar fashion to mammals. In both mammals and snakes the parathyroid hormone and Calcitonin, respectively, are the hypercalcemic and hypocalcemic hormone. Just like in humans, snakes raise their levels of PTH while digestion takes place to absorb calcium, and raise calcitonin levels to release calcium from its bones. The characteristics of this process didn’t change as a result of the diet snakes were exposed to. Nonetheless, the levels of each hormone in snakes exposed to different diets were greatly impacted. Fasting snakes and snakes with a normal diet exhibited blood calcium levels of one to 1.5 millimoles, accompanied by roughly similar levels of calcitonin and PTH for the normal feeding snake and higher levels of calcitonin than PTH for the fasting snake. The snake exposed to a low calcium diet, however, had a greater variability among these. In five days, its blood calcium levels sharply decreased from 1.4 millimoles to roughly 0.5 millimoles, Its calcitonin levels stayed between three and 8 millimoles and PTH levels increased from 0 millimoles on day one to 14 millimoles on day five.
As a consequence of the largely preliminary atmosphere surrounding the experiment, the author didn’t do a great job exposing intestinal crypts as a new cell type. Even thought the author vividly described the composition of intestinal crypts, theorized its main function and acquired meaningful data regarding its functioning in a snake’s intestines, he didn’t directly correlate his findings to how crypts could be a new cell type. As of my current understanding of this investigation, his aim wasn’t to establish the cellular works of the crypts; but rather to identify the characteristics of crypts and their relation to surrounding epithelial tissue. Therefore, it isn’t clear if its functioning is that of a temporal cellular dumpsite where iron ions precipitate calcium ions unused by neighboring cells or that of a specialized cell.
To conclude, the characteristics of intestinal crypts differ as a result of a snake’s diet. The high degree of plasticity Burmese Pythons’ intestines possess, allows them to rapidly recover from long fasting periods. Lignot experiment tried to emulate a competitive environment in which some Burmese Python would successfully hunt and others wouldn’t. Accounting for this variability, him and his colleagues created diets a different snake would be exposed to. As a result of the data gathered, they successfully deduced the elemental composition of intestinal crypts and determined conditions were they more frequently appear. Even though the experiment’s focus wasn’t to directly highlight these crypts as new, specialized cells, it opened the door for future experiments to determine their functioning