Submitted to: Animal Science Progress Report
Publication Type: Other
Publication Acceptance Date: 10/27/2000
Publication Date: N/A
Technical Abstract: This is the first study of porcine acid-labile subunit (ALS) expression in neonatal pigs. Reverse-transcription PCR (RT-PCR) was used to produce a partial cDNA clone of porcine ALS. The porcine cDNA was found to share 84% sequence identity with human ALS. The ALS cDNA clone was used to produce a probe to monitor levels of ALS mRNA in liver tissues. Northern blot analysis of porcine liver RNA revealed a solitary transcript of 2.5 kb. Following confirmation of the probe specificity, slot-blot analysis was used to determine hepatic mRNA levels. Two-week-old barrows were either cross-fostered to a sow (n = 8) or weaned onto a phase 1 diet (n =8). Piglets were allocated such that two size groups were equivalently represented in each experimental group (small, 7.7-9.5 lb and large, 10.2-12.5 lb). Animals were weighed daily and sacrificed 4 d after weaning for blood and tissue collection. Weaning produced the expected growth lag (P < .0001) and accompanying suppression of serum IGF-1 concentrations (P .0001). Weaning did not affect IGF-1, IGFBP-3, or ALS mRNA expression; however, large pigs had significantly greater levels of liver ALS mRNA than small pigs (P = .0003). Hepatic ALS expression was also significantly correlated with growth in an additional group of 2-wk-old nursing gilts (r = .73, P = .0008, n = 16).