Postprandial morphological response of the intestinal epithelium of the Burmese python (Python molurus)

The postprandial morphological changes of the intestinal epithelium of Burmese pythons were examined using fasting pythons and at eight time points after feeding. In fasting pythons, tightly packed enterocytes possess very short microvilli and are arranged in a pseudostratified fashion. Enterocyte width increases by 23% within 24 h postfeeding, inducing significant increases in villus length and intestinal mass. By 6 days postfeeding, enterocyte volume had peaked, following as much as an 80% increase. Contributing to enterocyte hypertrophy is the cellular accumulation of lipid droplets at the tips and edges of the villi of the proximal and middle small intestine, but which were absent in the distal small intestine. At 3 days postfeeding, conventional and environmental scanning electron microscopy revealed cracks and lipid extrusion along the narrow edges of the villi and at the villus tips. Transmission electron microscopy demonstrated the rapid postprandial lengthening of enterocyte microvilli, increasing 4.8-fold in length within 24 h, and the maintaining of that length through digestion. Beginning at 24 h postfeeding, spherical particles were found embedded apically within enterocytes of the proximal and middle small intestine. These particles possessed an annular-like construction and were stained with the calcium-stain Alizarine red S suggesting that they were bone in origin. Following the completion of digestion, many of the postprandial responses were reversed, as observed by the atrophy of enterocytes, the shortening of villi, and the retraction of the microvilli. Further exploration of the python intestine will reveal the underlying mechanisms of these trophic responses and the origin and fate of the engulfed particles

Management Systems That Increase Uniformity of the Forage Supply for Year-round Grazing by Spring Calving Herds

A comparison was made between two different systems: a year-round grazing system and a minimal-land grazing system at the McNay Research Farm, Chariton IA. The winter component of a year-round grazing system used sequential grazing of corn crop residues and stockpiled grass legume forages. The winter component of a minimal land system consisted of cows maintaining in drylot. Following grain harvest, four 7.5-acre fields containing corn crop residues were stocked with cows at midgestation at an allowance of 1.5 acres per cow. After 2 months, cows in the year-round grazing system grazed stockpiled tall fescue-red clover or smooth bromegrass-red clover forage at 3 acres/cow for approximately 4 months. Forage organic yields at the initiation of grazing were 3,467 lb./acre for three years on corn crop reside fields and 2,473 and 1,968 for stockpiled tall fescue-red clover and smooth bromegrass-red clover fields. In all years, no seasonal differences in body weight or body condition scores were observed between cows sequentially grazing corn crop residues and stockpiled forage or cows maintained in drylot during winter. Grazing cows consumed less hay resulting in a 3-year average hay excess of 4,235 and 4,743 pounds of hay dry matter per cow in the yearround grazing systems while the minimal land system was deficient in hay by 4,529 pounds of hay dry mater per cow. The summer component of a year-round grazing system involved rotational stocking of smooth bromegrassorchardgrass- birdsfoot trefoil pastures with cow-calf pairs and stocker yearlings at .75 animal units/acre for 40 days, and hay harvest and grazing of tall fescue-red clover and smooth bromegrass-red clover pastures at .33 cow-calf pairs/acre for 57 days and 83 days grazing of smooth bromegrass-orchardgrass-birdsfoot trefoil pastures at .5 cow-calf units per are. The minimal land system involved the rotational stocking of smooth bromegrass-orchardgrass-birdsfoot trefoil pastures with cow-calf pairs grazing at .64 animal units/acre and hay removal from 40% of the pasture. Grazing system did not affect cow body weight, condition score, or calf daily gain in any of the three years. Growing animal production was affected by grazing system; the minimal land system 3-year average was 181 lb./acre compared with year-round system averages of 128.7 and 123.9 lb./acre. The year-round grazing systems also produced more net winter forage than did the minimal land system. Differences in forage quality were only observed between tall fescue-red clover, smooth bromegrass-red clover and smooth bromegrassorchardgrass- birdsfoot trefoil pastures during summer

Sequencing the genome of the Burmese python (Python molurus bivittatus) as a model for studying extreme adaptations in snakes

The Consortium for Snake Genomics is in the process of sequencing the genome and creating transcriptomic resources for the Burmese python. Here, we describe how this will be done, what analyses this work will include, and provide a timeline

A multi-organ transcriptome resource for the Burmese Python (Python molurus bivittatus)

<p>Abstract</p> <p>Background</p> <p>Snakes provide a unique vertebrate system for studying a diversity of extreme adaptations, including those related to development, metabolism, physiology, and venom. Despite their importance as research models, genomic resources for snakes are few. Among snakes, the Burmese python is the premier model for studying extremes of metabolic fluctuation and physiological remodelling. In this species, the consumption of large infrequent meals can induce a 40-fold increase in metabolic rate and more than a doubling in size of some organs. To provide a foundation for research utilizing the python, our aim was to assemble and annotate a transcriptome reference from the heart and liver. To accomplish this aim, we used the 454-FLX sequencing platform to collect sequence data from multiple cDNA libraries.</p> <p>Results</p> <p>We collected nearly 1 million 454 sequence reads, and assembled these into 37,245 contigs with a combined length of 13,409,006 bp. To identify known genes, these contigs were compared to chicken and lizard gene sets, and to all Genbank sequences. A total of 13,286 of these contigs were annotated based on similarity to known genes or Genbank sequences. We used gene ontology (GO) assignments to characterize the types of genes in this transcriptome resource. The raw data, transcript contig assembly, and transcript annotations are made available online for use by the broader research community.</p> <p>Conclusion</p> <p>These data should facilitate future studies using pythons and snakes in general, helping to further contribute to the utilization of snakes as a model evolutionary and physiological system. This sequence collection represents a major genomic resource for the Burmese python, and the large number of transcript sequences characterized should contribute to future research in this and other snake species.</p

Report from the First Snake Genomics and Integrative Biology Meeting

This report summarizes the proceedings of the 1st Snake Genomics and Integrative Biology Meeting held in Vail, CO USA, 5-8 October 2011. The meeting had over twenty registered participants, and was conducted as a single session of presentations. Goals of the meeting included coordination of genomic data collection and fostering collaborative interactions among researchers using snakes as model systems.Organismic and Evolutionary Biolog

Report from the First Snake Genomics and Integrative Biology Meeting

This report summarizes the proceedings of the 1st Snake Genomics and Integrative Biology Meeting held in Vail, CO USA, 5-8 October 2011. The meeting had over twenty registered participants, and was conducted as a single session of presentations. Goals of the meeting included coordination of genomic data collection and fostering collaborative interactions among researchers using snakes as model systems

In Situ Study of the Physical Mechanisms Controlling Induced Seismicity at Monticello Reservoir, South Carolina

In two ~1.1-km-deep wells, the magnitudes of the principal in situ stresses, pore pressure, permeability, and the distribution of faults, fractures, and joints were measured directly in the hypocentral zones of earthquakes induced by impoundment of Monticello Reservoir, South Carolina. Analysis of these data suggests that the earthquakes were caused by an increase in subsurface pore pressure sufficiently large to trigger reverse-type fault motion on preexisting fault planes in a zone of relatively large shear stresses near the surface. The measurements indicated (1) near-critical stress differences for reverse-type fault motion at depths less than 200-300 m, (2) possibly increased pore pressure at depth relative to preimpoundment conditions, (3) the existence of fault planes in situ with orientations similar to those determined from composite focal plane mechanisms, and (4) in situ hydraulic diffusivities that agree well with the size of the seismically active area and time over which fluid flow would be expected to migrate into the zone of seismicity. Our physical model of the seismicity suggests that infrequent future earthquakes will occur at Monticello Reservoir as a result of eventual pore fluid diffusion into isolated zones of low permeability. Future seismic activity at Monticello Reservoir is expected to be limited in magnitude by the small dimensions of the seismogenic zones

The Susceptibility of Trypanosomatid Pathogens to PI3/mTOR Kinase Inhibitors Affords a New Opportunity for Drug Repurposing

In our study we describe the potency of established phosphoinositide-3-kinase (PI3K) and mammalian Target of Rapamycin (mTOR) kinase inhibitors against three trypanosomatid parasites: Trypanosoma brucei, T. cruzi, and Leishmania sp., which are the causative agents for African sleeping sickness, Chagas disease, and leishmaniases, respectively. We noted that these parasites and humans express similar kinase enzymes. Since these similar human targets have been pursued by the drug industry for many years in the discovery of cellular growth and proliferation inhibitors, compounds developed as human anti-cancer agents should also have effect on inhibiting growth and proliferation of the parasites. With that in mind, we selected eight established PI3K and mTOR inhibitors for profiling against these pathogens. Among these inhibitors is an advanced clinical candidate against cancer, NVP-BEZ235, which we demonstrate to be a highly potent trypanocide in parasite cultures, and in a mouse model of T. brucei infection. Additionally, we describe observations of these inhibitors' effects on parasite growth and other cellular characteristics