Developmental control of collagen gene expression in the rat lung: confirmation of early observations of lung growth.
The short gestation period of the rat allows one to see rapid morphologic and biochemical changes in the lung. It has been shown that the rat lung undergoes a period of distension over the first several days of life followed by a rapid alveolar growth. Total lung collagen also increases during this time period. We have examined the changes in types I and III procollagen transcripts during the perinatal period and have compared them to the above observations. Total RNA was extracted from the lungs of offspring of time-pregnant Sprague-Dawley rats after large airways were removed. Northern hybridization was performed to determine the quality of steady-state RNA and rule out cross-hybridization while densitometric tracings of slot-blot hybridizations allowed comparative estimates of the target sequence of RNA. Immediately following birth, the steady-state mRNA procollagen levels increased and a shift to a predominant type I production occurred. These changes preceded the rapid increase of collagen content and alveolarization known to occur at three days of age. These data provide further evidence that collagen production is controlled at the level of transcription and in temporal and tissue-specific manners.
Larson
J E
JE
Alton Ochsner Medical Foundation, New Orleans, Louisiana 70121.
D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern; D003094:Collagen / Q000096:biosynthesis / Q000235:genetics*; D015870:Gene Expression; D008168:Lung / Q000254:growth & development*; D009693:Nucleic Acid Hybridization; D011347:Procollagen / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014158:Transcription, Genetic
D011347:Procollagen; D012333:RNA, Messenger; D003094:Collagen