Accumulation of abundant messenger ribonucleic acids during postnatal development of mouse small intestine
1Cell Biology Unit, Shriners Burns Institute, Boston, Massachusetts.
Abstract:
To describe the differentiation of the small bowel at the molecular level, intestinal messenger ribonucleic acids (mRNAs) from mice at different stages of fetal and postnatal development were investigated. On the basis of cell-free translation and complementary deoxyribonucleic acid cloning experiments, abundant mRNAs coding for small polypeptides of 6-12 kilodaltons (low-molecular-weight mRNAs) were found in adult small intestine but not in the fetal gut. These developmentally regulated low-molecular-weight mRNAs are uniquely abundant in jejunum and ileum of adult mice, but they are absent or occur only at low levels in the duodenum, colon, stomach, and all other mouse organs examined. Low-molecular-weight mRNAs begin accumulating in the small bowel at approximately 3 wk of age, coinciding with weaning and with profound changes in intestinal differentiation. One complementary deoxyribonucleic acid clone of a low-molecular-weight mRNA (asb4/134) is specific to the distal small bowel, specifically accumulates at weaning, and hybridizes to RNA from mouse testis and brain at approximately 2%-5% of the intestinal level. Low-molecular-weight mRNA sequences may provide important markers of intestinal differentiation at the genetic level, leading to a better understanding of the factors that contribute to its postnatal maturation.
Insights
Researchers identified specific messenger ribonucleic acids (mRNAs) that mark the molecular differentiation of the adult small intestine in mice. These low-molecular-weight mRNAs appear after weaning and are key indicators of intestinal maturation.
Area of Science:
- Molecular Biology
- Developmental Biology
- Genetics
Background:
- The small intestine undergoes significant molecular differentiation during postnatal development.
- Understanding the genetic markers of this differentiation is crucial for studying gut maturation.
Purpose of the Study:
- To identify and characterize molecular markers, specifically messenger ribonucleic acids (mRNAs), associated with small bowel differentiation in mice.
- To investigate the developmental regulation and tissue specificity of these identified mRNAs.
Main Methods:
- Analysis of intestinal messenger ribonucleic acids (mRNAs) from mice at various fetal and postnatal developmental stages.
- Utilizing cell-free translation and complementary deoxyribonucleic acid (cDNA) cloning techniques.
- Hybridization studies to determine mRNA tissue distribution and developmental accumulation.
Main Results:
- Abundant low-molecular-weight mRNAs (6-12 kilodaltons) were detected in the adult mouse small intestine but not in the fetal gut.
- These developmentally regulated mRNAs are highly specific to the jejunum and ileum of adult mice, with low levels in other organs.
- Low-molecular-weight mRNA accumulation begins around 3 weeks of age, coinciding with weaning and major intestinal differentiation events.
- A specific cDNA clone (asb4/134) identified a low-molecular-weight mRNA enriched in the distal small bowel post-weaning.
Conclusions:
- Low-molecular-weight mRNA sequences serve as significant molecular markers for small bowel differentiation at the genetic level.
- These findings contribute to a deeper understanding of the genetic factors influencing postnatal intestinal maturation.
- The identified mRNAs, particularly asb4/134, show specific accumulation patterns that can be utilized in further research on gut development.
