Expression of differentiated functions in the developing porcine small intestine

✍ Scribed by Giuditta Perozzi; Daniela Barilà; Chiara Murgia; Denise Kelly; Robert Begbie; Timothy P. King

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 700 KB
• Volume: 4
• Category: Article
• ISSN: 0955-2863
• DOI: 10.1016/0955-2863(93)90110-i

✦ Synopsis

Heterologotts" eDNA clones were used as hybridization probes to define the temporal expression of intestinal functions during fetal and postnatal development in the pig. Northern hybridization attalysis revealed the presence of the mRNAs for the cellular retinol binding protein CRBP 11, for the digestive enzyme aminopeptidase N, and for the microvillar proteins villin and ezrin in the small intestine of both weaned and 40-day fetal pigs. The presence of these mRNAs suggests that at the end of the first third of gestation the pig fetal intestine is already exhibiting some characteristics of a differentiated epithelium. The mRNAs for the two fatty acid-binding proteins I-FABP and L-FAPB, both involved in the metabolism of long chain fatty acids', were detected only in the intestinal mRNA extracted front weaned animals, while that .for the celhdar retinol-binding protein CRBP 1 was expressed only in the fetal tissue. The temporal limits of expression of intestinal genes in the pig epithelium seem therefore more easily deJined titan in other experimental animals with shorter times of fetal development. To isolate pig genes expressed at different developmental stages during intestinal epithelial cell differentiation, a eDNA library was constructed from poly(A) + RNA extracted.f?om mature pig intestine, l'his library was employed in the isolation of clones encoding CRBP 11 and L-FA BP. The nucleotide sequence of the two pig eDNA clones was determined, and the sequences of the deduced proteins compared with their hornologues from other species. The results of this analysis showed that the two pig, clones share a high level of homology with human and rat homologues both at the DNA and at the 9rotein level.