CFTR mRNA and its truncated splice variant (TRN-CFTR) are differentially expressed during collecting duct ontogeny.
The collecting duct epithelium originates from the embryonic ureter by branching morphogenesis. Ontogeny-dependent changes of CFTR mRNA expression were assessed by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) in primary monolayer cultures of rat ureteric buds (UB) and cortical collecting ducts, microdissected at different embryonic and postnatal developmental stages. The amount of wild-type CFTR-specific PCR product in UB declined to 20% of the initial value between embryonic gestational day E15 and postnatal day P1. After birth the CFTR product increased transiently between P1 and P7 by a factor of 10 and decreased towards day P14. PCR products specific for TRN-CFTR, a truncated splice variant, however, were low in early embryonic cells, increased markedly between day E17 and P2, and reached a plateau postnatally. Therefore, mRNA encoding TRN-CFTR does not appear to have a specific embryonic-morphogenetic function. By contrast, such function is suggested for wild-type CFTR mRNA as its abundance was high in early embryonic nephrogenesis, as well as during a postnatal period shortly before branching morphogenesis is completed.
Huber
S
S
Physiologisches Institut, Ludwig-Maximilians-Universität, Munich, Germany.
Braun
G
G
Burger-Kentischer
A
A
Reinhart
B
B
Luckow
B
B
Horster
M
M
D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D017403:In Situ Hybridization; D007668:Kidney / Q000166:cytology / Q000196:embryology*; D007684:Kidney Tubules / Q000196:embryology; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000378:metabolism
D012333:RNA, Messenger; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D012965:Sodium Chloride