Specific regulation of the gene expression of some pancreatic enzymes during postnatal development and weaning in the calf.
The construction of cDNA library from calf pancreas allowed us to examine the mRNA levels of four pancreatic hydrolases (chymotrypsin, lipase, trypsin and amylase) during postnatal development in preruminant and ruminant animals. The lack of parallel variations in the levels of the enzyme specific activities suggested that protein synthesis was not coordinately regulated. In preruminant calves, the change in chymotrypsin and lipase mRNA concentrations (0-28 day period) and in trypsin mRNA concentrations (0-119 day period) was opposite to that in the corresponding specific activities. In contrast, both the activity and mRNA profiles of amylase during the latter period, on the one hand, and those of chymotrypsin and lipase during the 28-119 day period, on the other hand, were comparable. However, the extent to which the specific activity and mRNA concentration of each enzyme were increased did not necessarily coincide. The observed changes in mRNA levels probably resulted from some transcriptional control of the gene expression and/or variation in mRNA stability. Moreover, a translational regulation of the messengers could explain the existence of non-parallel mRNA and specific activity profiles. In sharp contrast with the multiple control of protein synthesis during postnatal development in preruminant calves, weaning was found to induce the same increase in enzyme activity and corresponding mRNA for each of the four pancreatic enzymes, suggesting that pretranslational modulation of gene expression was mainly, if not exclusively, concerned.
Le Huërou
I
I
Centre de Biochimie et de Biologie Moléculaire du Centre National de la Recherche Scientifique, Marseille, France.
Wicker
C
C
Guilloteau
P
P
Toullec
R
R
Puigserver
A
A
D000375:Aging; D000681:Amylases / Q000235:genetics*; D000818:Animals; D000833:Animals, Suckling; D002417:Cattle; D002918:Chymotrypsin / Q000235:genetics*; D015342:DNA Probes; D015971:Gene Expression Regulation, Enzymologic; D015723:Gene Library; D008049:Lipase / Q000235:genetics*; D008297:Male; D009693:Nucleic Acid Hybridization; D010179:Pancreas / Q000201:enzymology / Q000254:growth & development*; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D014357:Trypsin / Q000235:genetics*; D014886:Weaning
D015342:DNA Probes; D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D008049:Lipase; D000681:Amylases; D002918:Chymotrypsin; D014357:Trypsin