Temporal and spatial expression of laminin, collagen types IV and I and alpha 6/beta 1 integrin receptor in the developing rat parotid gland.
We have examined the temporal expression and cellular localization of the genes and proteins for the extracellular matrix (ECM) proteins laminin (B1, B2 and A chain), collagen types alpha 1 (IV) and alpha 1 (I) and the integrin receptor complex alpha 6/beta 1, during parotid gland postnatal development. Laminin B1 and B2 isoforms and collagens alpha 1 (IV) and alpha 1 (I) mRNA steady-state levels were highest at ages 0, 7 and 14 days after birth and declined to the adult (90 days) level at 21 days and older. Laminin A chain transcripts were not detected at any age. Collagen alpha 1 (IV) and laminin were localized in the basal membrane of the developing acinar and ductal cells, while collagen alpha 1 (I) was localized in the stroma surrounding the cells. The amounts of these ECM components were high at the early stages of development and lower at later times. The pattern of expression of the alpha 6/beta 1 integrin genes during development was similar to those of laminin and collagens alpha 1 (IV) and alpha 1 (I). Accumulations of mRNA were high at 0, 7 and 14 days after birth and lower at 21 days and older. High levels of beta 1 integrin were localized in the developing acinar and ductal cell membranes at early ages (7 days); lower amounts were present in the same distribution pattern at later stages of gland development.(ABSTRACT TRUNCATED AT 250 WORDS)
Lazowski
K W
KW
Clinical Investigations and Patient Care Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892.
Mertz
P M
PM
Redman
R S
RS
Kousvelari
E
E
D000818:Animals; D003094:Collagen / Q000096:biosynthesis* / Q000145:classification / Q000235:genetics; D005109:Extracellular Matrix / Q000502:physiology; D005326:Fetal Proteins / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation; D039121:Integrin alpha6beta1; D016023:Integrins / Q000096:biosynthesis* / Q000235:genetics; D007797:Laminin / Q000096:biosynthesis* / Q000235:genetics; D010306:Parotid Gland / Q000254:growth & development / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013047:Specific Pathogen-Free Organisms; D013997:Time Factors
D005326:Fetal Proteins; D039121:Integrin alpha6beta1; D016023:Integrins; D007797:Laminin; D003094:Collagen