Meeting Abstract
P3.89 Tuesday, Jan. 6 Expression of the intestinal brush border disaccharidases and Na+/glucose cotransporter genes of zebra finch (Taeniopygia guttata) GATICA SOSA, C.; CHEDIACK, J.G.; JURI AYUB, M.; KARASOV, W.H.*; CAVIEDES-VIDAL, E.; Univ. Nac. San Luis, IMIBIO-SL, San Luis, Argentina; Univ. Nac. San Luis, IMIBIO-SL, San Luis, Argentina; Inst. Leloir, Argentina; Univ. of Wisconsin, Madison; Univ. Nac. San Luis, IMIBIO-SL, San Luis, Argentina wkarasov@wisc.edu
Digestive function of passerine birds (i.e. rates and capacities of intestinal nutrient hydrolysis and absorption) and its ecological implications has been studied extensively in different species at different levels of integration. However, to our knowledge the level of expression of the different intestinal membrane-bound enzyme and nutrient transporter genes that participate in the digestion and its regulation has yet not been assessed in passerines. Thus, our objectives were: (1) to assess mRNA levels along the small intestine for the intestinal enzymes sucrase-isomaltase (SI) and maltase-glucoamylase (MG)] and the Na+/glucose cotransporter (SGLT1), and (2) to associate the mRNA levels of the enzymes to their specific activities. Our passerine bird models were adult zebra finches, because they are easy to obtain and maintain, and their genome is being sequenced. We designed several primers using predicted sequences of SI, MG and SGLT1 genes for chicken and selected those that produced fragments with the highest percentage of homology to the zebra finch genome. cDNA fragments obtained by RT-PCR were cloned and sequenced for validation. We determined the abundances of mRNAs and activities along the small intestine for SI and MG, whereas for SGLT1 only mRNA abundance was assessed. SI mRNA abundance and activity were correlated and exhibited significant positional differences along the small intestine possibly indicating a transcriptional regulation. Interestingly, neither MG nor SGLT1 revealed a significant correlation or differences in the activity or mRNA abundance along the intestine. Supported by FONCYT PICT 25561, UNSL-CyT 22Q751 to EC-V, and NSF IOS-0615678 to WHK.
