INVESTIGADORES
BRUN Antonio
congresos y reuniones científicas
Título:
Bats and birds share digestive adaptations to an aerial lifestyle
Autor/es:
EDWIN R. PRICE; BRUN A; CAVIEDES-VIDAL E; KARASOV WH
Lugar:
San Diego
Reunión:
Congreso; Comparative Approaches to Grand Challenges in Physiology; 2014
Institución organizadora:
American Physiological Society
Resumen:
Powered flight evolved at least twice in vertebrates. We tested for shared digestive adaptations in two extant volant lineages. Bats
and birds, compared with nonflying mammals, share shorter intestines and smaller nominal intestinal surface areas (NSA), which
lowers digestive mass carried and thus improves flight maneuverability and economy. Intestinal hydrolytic enzyme and nutrient
transport activities appear similar among these groups per unit intestine, but lower over the entire intestine in the fliers. Nutrients
can also be absorbed paracellularly by passing through the tight junctions that link adjacent enterocytes. Seven bat species and
14 bird species, with a variety of natural diets, absorbed significantly more of ingested L-arabinose and other similarly sized,
metabolically inert, nonactively transported monosaccharides than 18 species of nonflying mammals. These differences in
nutrient-sized probe absorption were demonstrated at the tissue level comparing results from perfusion experiments (7 bat
species, 1 bird, 5 nonflying mammals) that control for several potential confounding factors. Greater amplification of digestive
surface area by villi and differences in expression patterns of junctional proteins (i.e., claudins and occludin) may provide
mechanistic explanations for the observation of higher paracellular absorption in bats and birds relative to nonflying mammals.
Supported by USA NSF and Argentina CONICET.