Expression, localization and developmental regulation of insulin-like growth factor I mRNA in rat submandibular gland.
The mRNA for insulin-like growth factor I (IGF-I) in the submandibular gland of mature and developing rats was examined by Northern blotting and in situ hybridization with an oligonucleotide probe. In the mature adult rat, IGF-I mRNA was expressed at a higher level in the submandibular gland than in the liver, and was localized primarily in the granular convoluted tubule (GCT) cells. A 4.7-kb mRNA on Northern blots, which was expressed only slightly in the liver, proved to be the predominant size species of IGF-I transcripts in the GCT cells, and its level increased progressively with the postnatal development of GCTs in the gland. In addition, a 1.8-kb mRNA for IGF-I was also expressed at a much lower level throughout the acinar and duct systems, irrespective of age. These results have shed a light on the status of IGF-I as one of the many biologically active polypeptides that are produced in the rodent submandibular gland.
Amano
O
O
Department of Anatomy, School of Medicine, Kanazawa University, Japan.
Iseki
S
S
D000367:Age Factors; D000818:Animals; D001345:Autoradiography; D001483:Base Sequence; D015152:Blotting, Northern; D005260:Female; D005786:Gene Expression Regulation; D017403:In Situ Hybridization; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D012333:RNA, Messenger / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D012737:Sex Factors; D013363:Submandibular Gland / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*
D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I