Controls on gut phosphatisation : the trilobites from the Weeks Formation Lagerstätte (Cambrian; Utah)

Despite being internal organs, digestive structures are frequently preserved in Cambrian Lagerstätten. However, the reasons for their fossilisation and their biological implications remain to be thoroughly explored. This is particularly true with arthropods--typically the most diverse fossilised organisms in Cambrian ecosystems--where digestive structures represent an as-yet underexploited alternative to appendage morphology for inferences on their biology. Here we describe the phosphatised digestive structures of three trilobite species from the Cambrian Weeks Formation Lagerstätte (Utah). Their exquisite, three-dimensional preservation reveals unique details on trilobite internal anatomy, such as the position of the mouth and the absence of a differentiated crop. In addition, the presence of paired pygidial organs of an unknown function is reported for the first time. This exceptional material enables exploration of the relationships between gut phosphatisation and the biology of organisms. Indeed, soft-tissue preservation is unusual in these fossils as it is restricted to the digestive structures, which indicates that the gut played a central role in its own phosphatisation. We hypothesize that the gut provided a microenvironment where special conditions could develop and harboured a source of phosphorus. The fact that gut phosphatization has almost exclusively been observed in arthropods could be explained by their uncommon ability to store ions (including phosphorous) in their digestive tissues. However, in some specimens from the Weeks Formation, the phosphatisation extends to the entire digestive system, suggesting that trilobites might have had some biological particularities not observed in modern arthropods. We speculate that one of them might have been an increased capacity for ion storage in the gut tissues, related to the moulting of their heavily-mineralised carapace

The nose and tongue as chemical detectors

Human chemical senses are the gatekeepers of our digestive system. Chemical separation combined with human sensory perception has been used to isolate and identify a natural non-steroidal anti-inflammatory compound in olive oil.<br /

The glucagon-like Peptide-2

Multiple peptide hormones produced within the gastrointestinal system act also in the central nervous system and aid in the regulation of energy homeostasis and metabolism. The list of these peptides is progressively increasing and includes glucagon-like peptide 2 (GLP-2) as an anorexigenic factor. GLP-2 is released from enteroendocrine L-cells following food intake and its principal target is represented by the gastrointestinal tract. GLP-2 has been shown to be an important intestinotrophic factor that stimulates epithelial cell proliferation and inhibits apoptosis. GLP-2 increases intestinal blood flow and the activity and expression of epithelial brush-border digestive enzymes and nutrient transporters, and consequently increases the intestinal digestive and absorptive capacity. It inhibits gastric and intestinal motility, thus providing another mechanism to increase absorption of nutrients. Current research has focused on determining its physiological actions and its biological mechanisms in the gut, while very little is known on the GLP-2 actions within the brain. This review provides an overview of the state of the art on GLP-2 biology.peer-reviewe

The substrate of the biopsychosocial influences in the carcinogenesis of the digestive tract

Digestive cancer represents a severe public health problem, being one of the main causes of death. It is considered a multifactorial disease, with hereditary predisposition, environmental factors, and other factors involved in carcinogenesis. Both the evolution and the pathogenesis of digestive neoplasms remain incompletely elucidated. As a multifactorial disease, it can be approached by taking into account the biopsychosocial influences via enteric nervous system. Many peptides and non-peptides having a neurotransmitter role can be found in the enteric nervous system, which can influence the neoplastic process directly or indirectly by affecting some angiogenic, growth, and metastasis factors. However, neurotransmitters can also cause directly, through intercellular signalizing, the angiogenesis, the proliferation, and the digestive neoplasms’ metastasis. This new approach to neoplasms of the digestive tube assumes broader psychosocial factors can play an important role in the understanding the ethiopathogenie, the evolution of the disease, and determination of possible molecular targeted therapies; it also suggests that behavioral strategies may be important for maintaining a healthy state with respect to the digestive tract

Outreach Education: Making Neuroscience Readily Available for Rural Students and Communities of Alaska

WHAT is neuroscience? Neuroscience is the scientific study of the structure or function of the nervous system and brain. To get a grasp on the vast study of neuroscience, first think of the human body and how complex it is. Think of the skeletal system and the muscular, nervous, digestive and respiratory systems that make up the human body and keep it running in tip top shape. Now think of the brain, a singular organ of soft nervous tissue that one-handedly controls all of those other systems, including both mental and physical actions. Sounds a bit daunting doesn’t it

Glycocalyx production in teleosts [Translation from: Verhandlungen der Deutschen Zoologischen Gesellschaft, p.286, 1970]

Shielding the organism against harmful effects from the environment is one of the most important tasks of the outer covering of all animals. The epidermis of primarily aquatic organisms and the epithelia of organs which are exposed to water, such as the digestive or the urinary system, possess a film of glycoproteins and mucopolysaccharides, the glycocalyx. This short paper examines the relationship of the mucus cells with the glycocalyx

CONTROLLING KIDNEY WORMS IN SWINE IN THE SOUTHERN STATES

The kidney worm of swine is one of the most serious obstacles to profitable swine. production in the. South.. Since these parasites are located in the liver, kidney fat, kidney tissue proper, blood vessels, and other parts of the body outside the digestive system, they cannot be removed by any known medicinal treatment. The only hopeful outlook for the control of these parasites is a system of management designed to protect hogs from the infective larvae of the worms. These larvae develop from eggs eliminated with the urine of infected hogs. (Fig. 1.) Larvae of the kidney worm are prevalent on hog pastures in practically all the Southern States

Control of growth and gut maturation by HoxD genes and the associated lncRNA Haglr.

During embryonic development, Hox genes participate in the building of a functional digestive system in metazoans, and genetic conditions involving these genes lead to important, sometimes lethal, growth retardation. Recently, this phenotype was obtained after deletion of Haglr, the Hoxd antisense growth-associated long noncoding RNA (lncRNA) located between Hoxd1 and Hoxd3 In this study, we have analyzed the function of Hoxd genes in delayed growth trajectories by looking at several nested targeted deficiencies of the mouse HoxD cluster. Mutant pups were severely stunted during the suckling period, but many recovered after weaning. After comparing seven distinct HoxD alleles, including CRISPR/Cas9 deletions involving Haglr, we identified Hoxd3 as the critical component for the gut to maintain milk-digestive competence. This essential function could be abrogated by the dominant-negative effect of HOXD10 as shown by a genetic rescue approach, thus further illustrating the importance of posterior prevalence in Hox gene function. A role for the lncRNA Haglr in the control of postnatal growth could not be corroborated

Digestive enzymes in Rhinolophus euryale (Rhinolophidae, Chiroptera) are active also during hibernation

During the winter, bats use hibernation as a means of surviving the period of low prey offer. However, the&nbsp;Mediterranean horseshoe bat (Rhinolophus euryale) arouses from torpor quite frequently. Based on the actual&nbsp;climatic conditions, it can profit from occasional foraging oportunities, when they occur. We analysed faeces&nbsp;collected on four nights during the period from November 2012 to February 2013 from the Domica-Baradla cave&nbsp;system (Slovakia and Hungary). In mid-November, the largest proportion of faecal contents were from Lepidoptera.&nbsp;Later on, the proportion of non-consumptive mass in the faeces increased and prey remnants disappeared.&nbsp;We analysed the activity of digestive enzymes (amylase, chitobiase, endochitinase and glukosaminidase) in&nbsp;faeces. The activity of these enzymes was detected in fresh faeces throughout the whole winter. The faecal&nbsp;activity of the chitinases was relatively stable during the monitored period, whilst the activity of amylase was&nbsp;highest during late November and December. Some level of active digestive enzymes during the winter could be an adaptation to occasional winter foraging

Morphology and histology of the digestive gland of Oxychilus (Drouetia) atlanticus (Morelet & Drouët) (Gastropoda: Pulmonata).

Little information exists on the histology of Zonitidae digestive system. This study deals with a detailed characterization of the different types of cells comprising epithelium lining the digestive gland of 0xychilus atlanticus. From light and scanning electron microscope (SEM) studies, three types of differentiated cells can be identified in the digestive gland: digestive cells, excretory cells and calcium cells. Digestive cells are the most numerous, and are present in two forms, one believed to be absorbing food material and the other secreting material. Excretory cells are distinguished by having a large central vacuole, containing excretory granules. Calcium cells contain spherules of calcium salts, which have a characteristic birefringence