Meeting Abstract

109-4  Sunday, Jan. 7 08:45 – 09:00  Intestinal α–Glucosidase Transcriptional Responses During Ontogeny and Diet Adjustment in Altricial Birds GATICA-SOSA, C; BRZĘK, P; MAGALLANES, M.E.; KARASOV, W.H.*; CAVIEDES-VIDAL, E.; Univ. San Luis, Argentina; Univ. Biaystok, Poland; Univ. San Luis, Argentina; Univ. Wisconsin-Madison; Univ. San Luis, Argentina wkarasov@wisc.edu http://labs.russell.wisc.edu/karasov/

We describe ontogenetic changes in maltasic activity and its mRNA in birds through adulthood, and in response to increase in dietary starch. We studied house sparrows (Passer domesticus), which undergo a natural switch from insects to starch-containing seed diet during development, and zebra finch (Taeniopygia guttata), which have a relatively fixed seed diet during development. In zebra finch, in whom maltasic activity increased with age but not with dietary starch, α–glucosidase mRNA was not affected by either age or dietary starch level. In house sparrow nestlings, in whom maltasic activity increased with age and with added starch, α–glucosidase mRNA was higher on diet with added starch but did not clearly increase with age. These results are consistent with the idea that the apparent programmed ontogenetic increase in maltasic activity is not mainly via transcriptional control of α–glucosidase, whereas induction of maltasic activity by increased dietary starch is. Supported by NSF IOS-1354893