Latest news with #JehanHerveLignot
Yahoo
3 days ago
- Science
- Yahoo
New Cell Discovered in Pythons Allows Them to Completely Digest Bones
When carnivores that roam our Earth feast gleefully on the flesh of their prey, the hard, unpalatable bones are usually left behind. But snakes can unhinge their jaws to swallow their meals whole – and, unlike other animals that pass or regurgitate the bones they cannot break down, the skeletons swallowed by snakes do not re-emerge in a recognizable format. Exactly how snake bodies pull off this astonishing feat of bone digestion has been unclear. Now, scientists have found a previously unknown type of cell in the intestines of Burmese pythons (Python molurus bivittatus) that appears to enable them to completely and utterly absorb the skeletons of their prey. These cells help process large amounts of calcium and phosphorus that would otherwise overload the snake's system. Related: "A morphological analysis of the python epithelium revealed specific particles that I'd never seen in other vertebrates," says biologist Jehan-Hervé Lignot of the University of Montpellier in France. "Unlike normal absorbing enterocytes, these cells are very narrow, have short microvilli, and have an apical fold that forms a crypt." Only a few animal species have been observed deliberately eating bones, a practice known as osteophagy. It's usually associated with the intake of phosphorus and calcium. Indeed, pet snakes that are only fed boneless food develop calcium deficiencies, so skeletons in fact appear to be a vital component of snakes' overall diet. But if calcium uptake wasn't limited, snake bloodstreams could be overloaded. "We wanted to identify how they were able to process and limit this huge absorption of calcium through the intestinal wall," Lignot explains. The researchers used light and electron microscopy to study the enterocytes, cells lining the intestines, of Burmese pythons. They also took blood hormone and calcium measurements from snakes that were either fasting, fed normal prey, or fed boneless rats. The results revealed a specialized cell type that enables the snake to process and metabolize bones. "These cells have an apical crypt possessing a multi-layered particle made of calcium, phosphorus, and iron-rich nucleation elements in the centre," the researchers write in their paper. "In fasting snakes, this cell type has empty crypts. When snakes are fed with boneless prey, particles are not produced by this cell type, although iron elements are located within the crypts. When calcium supplements are added to a boneless meal, large particles fill the crypts." In addition, no bones or bone fragments were found in the feces of the pythons, suggesting that the skeletons of their prey are completely digested. The particles in the cells' crypts, the researchers determined, are excess to the snake's requirements once it has extracted all it needs from the completely dissolved bones. The purpose of the newfound cells seems to be to sequester and excrete the excess dissolved calcium and phosphorus. In data that has not been published, the researchers identified the same cells in other reptiles: the common boa (Boa constrictor), green anaconda (Eunectes murinus), blood python (Python brongersmai), reticulated python (Malayopython reticulatus), Central African rock python (Python sebae), and carpet python (Morelia spilota). The Gila monster (Heloderma suspectum), a lizard, also possesses the cells. This suggests that the specialized cells may have evolved before the species diverged, or evolved multiple times in different animals. The researchers believe that other bone-eating animals that devour their prey whole may provide clues. "Marine predators that eat bony fish or aquatic mammals must face the same problem," Lignot says. "Birds that eat mostly bones, such as the bearded vulture, would be fascinating candidates too." The research has been published in the Journal of Experimental Biology and presented at the Society for Experimental Biology Annual Conference in Belgium Wild Orcas Filmed Offering Gifts of Food to Humans Scientific First: 'Slow-Motion' Earthquakes Captured in Real Time Alpha Male Primates a Myth, Researchers Find in New Study
Yahoo
4 days ago
- Health
- Yahoo
Pythons can devour bones thanks to unique stomach cells
Few predators swallow their prey whole. Even fewer can digest their meals with bones and all. But for some reptiles like the Burmese python (Python bivittatus), calcium-rich skeletons aren't a digestive concern—they're a necessity. Herpetologists have spent years trying to understand how bones are not only safe and healthy for the serpents, but how their biology manages to regulate when and how many bones to digest. Now, researchers believe they have identified an explanation hidden inside the 'crypts' of specialized cells. Their findings are published this week in the Journal of Experimental Biology. A team co-led by zoologist Jehan-Hervé Lignot at France's University of Montpellier began peering inside Burmese python intestines using light and electron microscopy in an effort to better understand their dietary cycle of fasting and feeding. Lignot soon spotted tiny, unidentified objects along the snake's intestinal lining, or epithelium. 'When I started analysing the 'spheroids' I initially thought it could be some bone fragments. But this rapidly proved to be wrong,' Lignot told Popular Science. 'And, then, came the hypothesis that the particles could be produced by the intestine and by a specific cell type.' A subsequent morphological analysis proved the theory correct: the spheroids were being produced from calcium, iron, and phosphorus within a newly identified type of cell. Specifically, the particles resided in what Lignot described as a 'crypt' inside these narrow, specialized cells—but it wasn't initially clear what these cells were programmed to do. To find out, researchers studied the pythons' intestinal cells after feeding them three different diets—a standard fare of whole rodents, a low-calcium variant of 'boneless prey,' and a version that featured boneless rodents with higher-than-normal injections of calcium. Pythons subsequently lacked the same calcium- and phosphorus-heavy particles when only fed boneless food. But when either snacking on regular bone-in rodents or a calcium-rich diet, snake cell crypts featured plenty of calcium, phosphorus, and iron spheroids. Additionally, those pythons' droppings contained no bone fragments, showing that they had been dissolved entirely. Lignot noted that while experts have previously located similar particles in insects and crustaceans, his team is the first to see something similar in vertebrates. Since then, he and his collaborators have also identified the bone-digesting cell in multiple other python and boa species, as well as the venomous Gila monster. As for how many bones an average python in the wild can digest, Lignot isn't quite sure—but he did offer a quick estimate. '[It's a] tough question… snakes can grab a prey that can be more than 30 percent of [its] body mass,' he said. 'If we consider, as in humans, that our bones represent about 9-10 percent of our body weight, you can therefore have a significant amount of ions coming from the prey's skeleton that is completely dissolved in the stomach.' While Lignot has since moved on to other research areas, he hopes other investigators continue to search for the newly pinpointed cell type in other vertebrates. 'An evolutionary analysis would be awesome,' he said.
Gizmodo
4 days ago
- Health
- Gizmodo
Scientists Discover Secret Weapon That Allows Pythons to Digest Bones
Pythons are notorious for their eating habits. After suffocating their prey with their lithe bodies, these large snakes swallow the animal whole. Now, researchers have shed new light on the cellular mechanisms that allow them to digest entire skeletons. The study, presented July 9 at the Society for Experimental Biology Annual Conference in Belgium and published in the Journal of Experimental Biology, investigated the intestinal cells of Burmese pythons. Adult males can grow to be 10 to 16 feet (3 to 5 meters) long, and their impressive size allows them to feed on a wide variety of mammals and birds, including deer and alligators. Unlike other carnivores that only eat flesh, snakes rely on animal skeletons as a calcium source. Absorbing all the available calcium from a skeleton, however, could result in too much of this nutrient entering the serpent's bloodstream. Called hypercalcemia, it can lead to heart conditions, high blood pressure, bone defects, and kidney failure in reptiles. 'We wanted to identify how [pythons] were able to process and limit this huge absorption of calcium through the intestinal wall,' said Jehan-Hervé Lignot, lead author and a professor at the University of Montpellier, in a statement. To that end, Lignot and his colleagues fed pythons one of three different diets: normal rats, boneless rats, or boneless rats enriched with calcium carbonate to match natural bone calcium levels. One group of snakes did not receive any of these diets and instead fasted for three weeks to provide a baseline. Three to six days post-feeding, the researchers humanely euthanized and dissected the snakes to extract their small intestines. They then analyzed the enterocytes, or intestinal lining cells, of the pythons using light and electron microscopes alongside measurements of blood calcium and hormone levels. This revealed a never-before-seen type of cell that produces large particles made from calcium, phosphorus, and iron. These particles form structures that Lignot calls 'spheroids.' 'A morphological analysis of the python epithelium revealed specific particles that I'd never seen in other vertebrates,' Lignot said. He and his colleagues found these particles inside the internal 'crypt'—a small pocket or cavity—of specialized cells that differed from traditional intestinal cells. 'Unlike normal absorbing enterocytes, these cells are very narrow, have short microvilli [finger-like membrane protrusions], and have an apical fold that forms a crypt,' he added. The three different diets that the pythons ate allowed the researchers to assess the function of these unique cells. In snakes that ate boneless prey, the enterocytes did not produce the calcium and phosphorous-rich particles. In those that ate either whole rodents or calcium-supplemented boneless rodents, however, the cells' crypts filled with large particles of calcium, phosphorus, and iron. This suggests that these cells play an important role in breaking down the bones of a python's prey. The researchers found no bones in the snakes' feces, confirming that all skeletons were completely digested and dissolved inside their bodies. Though it was first identified in Burmese pythons, this new cell type isn't unique to them. Since that initial discovery, the researchers have found these specialized bone-digesting cells in other species of pythons, boas, and the Gila monster, a species of venomous lizard native to the southwestern U.S. and Mexico. The findings seem to point to an understudied system of mineral regulation in the digestive tracts of reptiles. However, it is possible that this mechanism extends to other types of bone-eating carnivores too, such as sharks and other marine predators, aquatic mammals, or raptors like the bearded vulture, according to Lignot. He told Gizmodo he hopes this work will inspire other researchers to search for these newly discovered cells across the animal kingdom.
