Laminin alpha 1, alpha 2, alpha 4 and beta 1 chain mRNA expression in mouse embryonic, neonatal, and adult hearts.

We examined the relative expression of laminin alpha 1, alpha 2, alpha 4 and beta 1 chain genes in the heart of embryonic, neonatal and adult BALb/c mice. The reverse transcriptase-polymerase chain reaction was employed to determine the mRNA expression of these chains because of the relatively small amount of RNA extracted from rat embryonic hearts. Glyceraldehyde 3-phosphate dehydrogenase and beta-actin were used as internal controls. Among the hearts examined, a relatively high expression of laminin alpha 1 chain was observed in the embryonic hearts, while its expression was very weak in the neonatal and negligible in the adult hearts. Conversely, expression of laminin alpha 2 chain was virtually not observed in the embryonic hearts, but this chain was expressed weakly in the neonatal and substantially in the adult hearts. Similar to laminin alpha 1, laminin alpha 4 was expressed in the embryonic hearts, while its expression was relatively weak in the neonatal and adult hearts. Laminin beta 1 was expressed in the hearts of mice at all stages examined. These results demonstrate that the laminin chain gene expression changes in the different developmental stages of the hearts of BALb/c mice.