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Vertebrate diets and digestive physiologies vary tremendously. Although the contribution of ecological and behavioral features to such diversity is well documented, the roles and identities of individual intestinal enzymes shaping digestive traits remain largely unexplored. Here, we show that the sucrase-isomaltase (SI)/maltase-glucoamylase (MGAM) dual enzyme system long assumed to be the conserved disaccharide and starch digestion framework in all vertebrates is absent in many lineages. Our analyses indicate that independent duplications of an ancestral SI gave rise to the mammalianspecific MGAM, as well as to other duplicates in fish and birds. Strikingly, the duplicated avian enzyme exhibits similar activities to MGAM, revealing an unexpected case of functional convergence. Our results highlight digestive enzyme variation as a key uncharacterized component of dietary diversity in vertebrates. Fil: Brun, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Mendez Aranda, Daniel. Max Planck Institute für Ornithologie; Alemania Fil: Magallanes Alba, Melisa Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Karasov, William H.. University of Wisconsin; Estados Unidos Fil: Martínez del Rio, Carlos. University of Wyoming; Estados Unidos Fil: Baldwin, Maude W.. Max Planck Institute für Ornithologie; Alemania Fil: Caviedes Vidal, Enrique Juan Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina

Although dietary flexibility in digestive enzyme activity (i.e., reaction rate) is widespread in vertebrates, mechanisms are poorly understood. When laboratory rats are switched to higher protein diet, the activities of apical intestinal peptidases increase within 15 h, in some cases by rapid increase in enzyme transcription followed by rapid translation and translocation to the intestine's apical, brush border membrane (BBM). Focusing on aminopeptidase-N (APN), we studied intestinal digestive enzyme flexibility in birds, relying on activity and mRNA data from the same animals. Our model was nestling house sparrows (Passer domesticus), already known to modulate intestinal peptidase activity when switching between lower and higher protein diets. Twenty-four hours after a switch from an adequate, lower protein diet to a higher protein diet, APN activity was increased in both whole intestinal tissue homogenates and in isolated BBM, but not at 12 h post-diet switch. Twenty-four hours after a reverse switch back to the lower protein diet, APN activity was decreased, but not at 12 h post-diet switch. Changes in APN activity in both diet switch experiments were associated with parallel changes in APN mRNA. Although transcriptional changes seem an important mechanism underlying dietary modulation of intestinal peptidase in both nestling house sparrows and laboratory rodents, the time course for modulation in nestlings seemed slower (to take approximately twice as long) compared to laboratory rodents. It may be ecologically advantageous if nestlings biochemically restructure their gut in response to a sustained increase in insects and protein intake rather than one or a few lucky insect meals.

In the small intestine transcellular and paracellular pathways are implicated in water-soluble nutrient absorption. In small birds the paracellular pathway is quantitatively important while transcellular pathway is much more important in terrestrial mammals. However, there is not a clear understanding of the mechanistic underpinnings of the differences among taxa. This study was aimed to test the hypothesis that paracellular permeability in perfused intestinal segments is higher in passerine birds than rodents. We performed in situ intestinal perfusions on individuals of three species of passerine birds (Passer domesticus, Taeniopygia guttata and Furnarius rufus) and two species of rodents (Mus musculus and Meriones ungiculatus). Using radio-labelled molecules, we measured the uptake of two nutrients absorbed by paracellular and transcellular pathways (L-proline and 3–O–methyl–D-glucose) and one carbohydrate that has no mediated transport (L-arabinose). Birds exhibited ~2 to ~3 times higher L-arabinose clearance per cm2 epithelium than rodents. Moreover, paracellular absorption accounted for proportionally more of 3–O–methyl–D-glucose and L-proline absorption in birds than in rodents. These differences could be explained by differences in intestinal permeability and not by other factors such as increased retention time or higher intestinal nominal surface area. Furthermore, analysis of our results and all other existing data on birds, bats and rodents shows that insectivorous species (one bird, two bats and a rodent) had only 30% of the clearance of L-arabinose of non-insectivorous species. This result may be explained by weaker natural selection for high paracellular permeability in animal- than in plant-consumers. Animal-consumers absorb less sugar and more amino acids, whose smaller molecular size allow them to traverse the paracellular pathway more extensively and faster than glucose. Fil: Garro, Cintia Araceli. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Humanas. Laboratorio de Biología "Profesor Enrique Cavides Codelia"; Argentina Fil: Brun, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Humanas. Laboratorio de Biología "Profesor Enrique Cavides Codelia"; Argentina. University of Wisconsin; Estados Unidos Fil: Karasov, William. University of Wisconsin; Estados Unidos Fil: Caviedes Vidal, Enrique Juan Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Humanas. Laboratorio de Biología "Profesor Enrique Cavides Codelia"; Argentina

Recent research often lauds the services and beneficial effects of host-associated microbes on animals. However, hosting these microbes may come at a cost. For example, germ-free and antibiotic-treated birds generally grow faster than their conventional counterparts. In the wild, juvenile body size is correlated with survival, so hosting a microbiota may incur a fitness cost. Avian altricial nestlings represent an interesting study system in which to investigate these interactions, given that they exhibit the fastest growth rates among vertebrates, and growth is limited by their digestive capacity. We investigated whether reduction and restructuring of the microbiota by antibiotic treatment would: (i) increase growth and food conversion efficiency in nestling house sparrows (Passer domesticus); (ii) alter aspects of gut anatomy or function (particularly activities of digestive carbohydrases and their regulation in response to dietary change); and (iii) whether there were correlations between relative abundances of microbial taxa, digestive function and nestling growth. Antibiotic treatment significantly increased growth and food conversion efficiency in nestlings. Antibiotics did not alter aspects of gut anatomy that we considered but depressed intestinal maltase activity. There were no significant correlations between abundances of microbial taxa and aspects of host physiology. Overall, we conclude that microbial-induced growth limitation in developing birds is not driven by interactions with digestive capacity. Rather, decreased energetic and material costs of immune function or beneficial effects from microbes enriched under antibiotic treatment may underlie these effects. Understanding the costs and tradeoffs of hosting gut microbial communities represents an avenue of future research. Fil: Kohl, Kevin. Vanderbilt University; Estados Unidos. University of Pittsburgh; Estados Unidos Fil: Brun, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of Wisconsin; Estados Unidos Fil: Bordenstein, Seth R.. Vanderbilt University; Estados Unidos Fil: Caviedes Vidal, Enrique Juan Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Karasov, William. University of Wisconsin; Estados Unidos

Flying mammals present unique intestinal adaptations, such as lower intestinal surface area than nonflying mammals, and they compensate for this with higher paracellular absorption of glucose. There is no consensus about the mechanistic bases for this physiological phenomenon. The surface area of the small intestine is a key determinant of the absorptive capacity by both the transcellular and the paracellular pathways; thus, information about intestinal surface area and micro‐anatomical structure can help explain differences among species in absorptive capacity. In order to elucidate a possible mechanism for the high paracellular nutrient absorption in bats, we performed a comparative analysis of intestinal villi architecture and enterocyte size and number in microchiropterans and rodents. We collected data from intestines of six bat species and five rodent species using hematoxylin and eosin staining and histological measurements. For the analysis we added measurements from published studies employing similar methodology, making in total a comparison of nine species each of rodents and bats. Bats presented shorter intestines than rodents. After correction for body size differences, bats had ~41% less nominal surface area (NSA) than rodents. Villous enhancement of surface area (SEF) was ~64% greater in bats than in rodents, mainly because of longer villi and a greater density of villi in bat intestines. Both taxa exhibited similar enterocyte diameter. Bats exceeded rodents by ~103% in enterocyte density per cm2 NSA, but they do not significantly differ in total number of enterocytes per whole animal. In addition, there is a correlation between SEF and clearance per cm2 NSA of L‐arabinose, a nonactively transported paracellular probe. We infer that an increased enterocyte density per cm2 NSA corresponds to increased density of tight junctions per cm2 NSA, which provides a partial mechanistic explanation for understanding the high paracellular absorption observed in bats compared to nonflying mammals. Fil: Brun, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. University of Wisconsin; Estados Unidos Fil: Fernández Marinone, Guido. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina Fil: Price, Edwin R.. University of North Texas; Estados Unidos Fil: Nell, Lucas A.. University of Wisconsin; Estados Unidos Fil: Simões, Beatriz M. V.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Castellar, Alexandre. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Gontero Fourcade, Manuel Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina Fil: Cruz-Neto, Ariovaldo P.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Karasov, William. University of Wisconsin; Estados Unidos Fil: Caviedes Vidal, Enrique Juan Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina

Here, we document the development of the House Sparrow Passer domesticus gut microbiota for the benefit of future ecological and evolutionary studies in this widely used avian system. We collected and inventoried luminal and mucosal samples from the distal guts of nestling House Sparrows between 3 and 12 days of age, and also collected similar samples from adult birds. Luminal bacterial community membership and structure differed significantly between nestlings and adults. The relative abundance of Proteobacteria in the lumen decreased around day 9, whereas the relative abundance of Firmicutes increased, demonstrating age‐related changes in the microbiota of House Sparrows. Fil: Kohl, Kevin. Vanderbilt University; Estados Unidos. University of Pittsburgh; Estados Unidos Fil: Brun, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. University of Wisconsin; Estados Unidos Fil: Caviedes Vidal, Enrique Juan Raul. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Karasov, William. University of Wisconsin; Estados Unidos

Background. Passerine birds exploit different kinds of feeding habits and they have to face seasonal changes in food availability. Therefore, the composition of the principal nutrient in their food differs from the usual. In consequence the digestive function ? enzyme hydrolysis and absorption ? have to adapt to these nutrients. These changes in digestive physiology could respond to the adaptive modulation hypothesis which postulated that the activities of digestive enzymes should match the levels of their substrates in their diet so energy is not wasted on enzymes that are no need. Thus, we decide to measure intestinal enzymes activities of two species of passerine birds that differ in natural diet. Overall we hypothesized that species with different feeding habits present enzyme activity according to the mainly component of the diet (e.g., carbohydrates, proteins). Our prediction is that the individuals will present enzyme activity proportionally to the primary components of the diets. Methods. We select for study: red ovenbirds (Furnarius rufus), which are strict insectivores and zebra finches (Taeniopygia guttata), which are specialist granivores. We complete the analysis with publish data for house sparrows (Passser domesticus) feed on high starch from the literature. To examine intestinal enzyme activities, we measured the activity of two disaccharidases (sucrase-isomaltase and maltase-glucoamilase) and one dipeptidase (aminopeptidase-N).Results. The average intestinal activity of sucrase shows that the omnivorous P. domesticus presents almost 4 times more activity than the granivorous T. guttata and more than 11 times than the insectivorous F. rufus. This difference is also reflected in the total sucrase hydrolytic capacity where P. domesticus has roughly 10 times more than the other two birds. Surprisingly in F. rufus we found maltase and aminopeptidase activity while sucrase activity was close to zero. In the case of the average activity of maltase for the omnivorous P. domesticus is approximately 40 % more than the granivorous T. guttata and more than 5 times than the insectivorous F. rufus. Although the total maltase hydrolytic capacity of P. domesticus is 5 times more than T. guttata and F. rufus. The average of aminopeptidase-N activity for F. rufus and T. guttata almost doubled the P. domesticus ones. Also F. rufus roughly doubles the other two birds in total aminopeptidase hydrolytic capacity.Discussion. This study has shown that exist a relationship between the levels of amino acids in the diet and the total aminopeptidase capacity, but in the case of carbohydrates this relationship is not evident. Fil: Garro, Cintia Araceli. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Brun, Antonio. University of Wisconsin; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Caviedes Vidal, Enrique Juan Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina

Animals maintain complex associations with a diverse microbiota living in their guts. Our understanding of the ecology of these associations is extremely limited in reptiles. Here, we report an in-depth study into the microbial ecology of gut communities in three syntopic and viviparous lizard species (two omnivores: Liolaemus parvus and Liolaemus ruibali and an herbivore: Phymaturus williamsi). Using 16S rRNA gene sequencing to inventory various bacterial communities, we elucidate four major findings: (i) closely related lizard species harbour distinct gut bacterial microbiota that remain distinguishable in captivity; a considerable portion of gut bacterial diversity (39.1%) in nature overlap with that found on plant material, (ii) captivity changes bacterial community composition, although host-specific communities are retained, (iii) faecal samples are largely representative of the hindgut bacterial community and thus represent acceptable sources for nondestructive sampling, and (iv) lizards born in captivity and separated from their mothers within 24 h shared 34.3% of their gut bacterial diversity with their mothers, suggestive of maternal or environmental transmission.Each of these findings represents the first time such a topic has been investigated in lizard hosts. Taken together, our findings provide a foundation for comparative analyses of the faecal and gastrointestinal microbiota of reptile hosts. Fil: Kohl, Kevin D. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Vanderbilt University; Estados Unidos Fil: Brun, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Magallanes Alba, Melisa Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Brinkerhoff, Joshua. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Laspiur, Julio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina Fil: Acosta, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina Fil: Caviedes Vidal, Enrique Juan Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Bordenstein, Seth R.. Vanderbilt University; Estados Unidos

While herbivory is a common feeding strategy in a number of vertebrate classes, less than 4% of squamate reptiles feed primarily on plant material. It has been hypothesized that physiological or microbial limitations may constrain the evolution of herbivory in lizards. Herbivorous lizards exhibit adaptations in digestive morphology and function that allow them to better assimilate plant material. However, it is unknown whether these traits are fixed or perhaps phenotypically flexible as a result of diet. Here, we maintained a naturally omnivorous lizard, Liolaemus ruibali, on a mixed diet of 50% insects and 50% plant material, or a plant-rich diet of 90% plant material. We compared parameters of digestive performance, gut morphology and function, and gut microbial community structure between the two groups. We found that lizards fed the plant-rich diet maintained nitrogen balance and exhibited low minimum nitrogen requirements. Additionally, lizards fed the plantrich diet exhibited significantly longer small intestines and larger hindguts, demonstrating that gut morphology is phenotypically flexible. Lizards fed the plant-rich diet harbored small intestinal communities that were more diverse and enriched in Melainabacteria and Oscillospira compared with mixed diet-fed lizards. Additionally, the relative abundance of sulfate-reducing bacteria in the small intestine significantly correlated with whole-animal fiber digestibility. Thus, we suggest that physiological and microbial limitations do not sensu stricto constrain the evolution of herbivory in lizards. Rather, ecological context and fitness consequences may be more important in driving the evolution of this feeding strategy. Fil: Kohl, Kevin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina. Vanderbilt University; Estados Unidos Fil: Brun, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina Fil: Magallanes Alba, Melisa Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina Fil: Brinkerhoff, Joshua. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina Fil: Laspiur, Julio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Biología; Argentina Fil: Acosta, Juan Carlos. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Biología; Argentina Fil: Bordenstein, Seth R.. Vanderbilt University; Estados Unidos Fil: Caviedes Vidal, Enrique Juan Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina

Rapid absorption and elimination of dietary water should be particularly important to flying species and were predicted to vary with the water content of the natural diet. Additionally, high water absorption capacity was predicted to be associated with high paracellular nutrient absorption due to solvent drag. We compared the water absorption rates of sanguivorous, nectarivorous, frugivorous, and insectivorous bats in intestinal luminal perfusions. High water absorption rates were associated with high expected dietary water load but were not highly correlated with previously measured rates of (paracellular) arabinose clearance. In conjunction with these tests, we measured water absorption and the paracellular absorption of nutrients in the intestine and stomach of vampire bats using luminal perfusions to test the hypothesis that the unique elongated vampire stomach is a critical site of water absorption. Vampire bats’ gastric water absorption was high compared to mice but not compared to their intestines. We therefore conclude that (1) dietary water content has influenced the evolution of intestinal water absorption capacity in bats, (2) solvent drag is not the only driver of paracellular nutrient absorption, and (3) the vampire stomach is a capable but not critical location for water absorption. Fil: Price, Edwin R.. University of Wisconsin; Estados Unidos Fil: Brun, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Humanas; Argentina Fil: Gontero Fourcade, Manuel Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Humanas; Argentina Fil: Fernández Marinone, Guido. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Humanas; Argentina Fil: Cruz Neto, Ariovaldo P.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Karasov, William H.. University Of Wisconsin; Estados Unidos Fil: Caviedes Vidal, Enrique Juan Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Humanas; Argentina. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina

Flying vertebrates (birds and bats) are under selective pressure to reduce the size of the gut and the mass of the digesta it carries. Compared to similar sized non-flying mammals, birds and bats have smaller intestines and shorter retention times. We review evidence that birds and bats have lower spare digestive capacity and partially compensate for smaller intestines with increased paracellular nutrient absorption. Fil: Price, Edwin. University Of Wisconsin; Estados Unidos Fil: Brun, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Caviedes Vidal, Enrique Juan Raul. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Humanas. Laboratorio de Biología "Profesor Enrique Cavides Codelia"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Karasow, William H.. University Of Wisconsin; Estados Unidos

Metabolites present in liver provide important clues regarding the physiological state of an organism. The aim of this work was to evaluate a protocol for high-throughput NMR-based analysis of polar and non-polar metabolites from a small quantity of liver tissue. We extracted the tissue with a methanol/chloroform/water mixture and isolated the polar metabolites from the methanol/water layer and the non-polar metabolites from the chloroform layer. Following drying, we re-solubilized the fractions for analysis with a 600 MHz NMR spectrometer equipped with a 1.7 mm cryogenic probe. In order to evaluate the feasibility of this protocol for metabolomics studies, we analyzed the metabolic profile of livers from house sparrow (Passer domesticus) nestlings raised on two different diets: livers from 10 nestlings raised on a high protein diet (HP) for 4 d and livers from 12 nestlings raised on the HP diet for 3 d and then switched to a high carbohydrate diet (HC) for 1 d. The protocol enabled the detection of 52 polar and nine non-polar metabolites in 1H NMR spectra of the extracts. We analyzed the lipophilic metabolites by one-way ANOVA to assess statistically significant concentration differences between the two groups. The results of our studies demonstrate that the protocol described here can be exploited for high-throughput screening of small quantities of liver tissue (approx. 100 mg wet mass) obtainable from small animals. Fil: Fathi, Fariba. University of Wisconsin; Estados Unidos Fil: Brun, Antonio. University of Wisconsin; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Rott, Katherine H.. University of Wisconsin; Estados Unidos Fil: Cobra, Paulo Falco. University of Wisconsin; Estados Unidos Fil: Tonelli, Marco. University of Wisconsin; Estados Unidos Fil: Eghbalnia, Hamid R.. University of Wisconsin; Estados Unidos Fil: Caviedes Vidal, Enrique Juan Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Karasov, William. University of Wisconsin; Estados Unidos Fil: Markley, John L.. University of Wisconsin; Estados Unidos