Expression of mRNA coding for pituitary hormones and pituitary-specific transcription factor in the pituitary gland of the rdw rat with hereditary dwarfism.
The rdw rat (gene symbol: rdw) with hereditary dwarfism has been shown immunohistochemically to have subnormal numbers not only of GH- but also of prolactin- and thyrotrophin-positive cells. To characterize the dwarfism of this strain, the expression of pituitary hormone mRNAs was examined by Northern hybridization. The pituitary gland in the rdw rat expressed 30-100 times less GH and prolactin mRNAs than normal controls, whereas mRNAs for pro-opiomelanocortin and the alpha subunit of rat glycoprotein hormone revealed a significant increase. There was a non-significant difference in rat LH-beta subunit and FSH-beta subunit between normal and rdw rats. The suppressed expression of a pituitary-specific transcription factor, Pit-1, is considered to cause hereditary dwarfism in mouse strains Snell and Jackson, whose phenotypes resemble those of the rdw rat. In this study, however, no difference in mRNA expression for Pit-1 was found between rdw rats and controls. This work indicates that the rdw rat may not have the same genotype as the phenotypically similar dwarf mice, Snell, Jackson and Ames.
Shibayama
K
K
Department of Pediatrics, Kitasato University School of Medicine, Kanagawa, Japan.
Ohyama
Y
Y
Ono
M
M
Furudate
S
S
D000818:Animals; D015152:Blotting, Northern; D004268:DNA-Binding Proteins / Q000235:genetics*; D004393:Dwarfism, Pituitary / Q000235:genetics*; D013006:Growth Hormone / Q000032:analysis; D010902:Pituitary Gland / Q000737:chemistry / Q000502:physiology*; D010907:Pituitary Hormones / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D011922:Rats, Mutant Strains / Q000235:genetics*; D013974:Thyroxine / Q000032:analysis; D050817:Transcription Factor Pit-1; D014157:Transcription Factors / Q000235:genetics*
D004268:DNA-Binding Proteins; D010907:Pituitary Hormones; C494186:Pou1f1 protein, rat; D012333:RNA, Messenger; D050817:Transcription Factor Pit-1; D014157:Transcription Factors; D013006:Growth Hormone; D013974:Thyroxine