Growth enhancement of transgenic mice expressing human insulin-like growth factor I.
A line of transgenic mice carrying a chimeric gene composed of human insulin-like growth factor I (IGF-I) coding sequences fused to the mouse metallothionein I promoter was generated to study the effects of chronically elevated exposure to IGF-I. Mice in this line overexpress IGF-I in most tissues studied and have circulating IGF-I levels 1.5 times the normal value. This results in a growth response manifested by a 1.3-fold increase in weight as a result of selective organomegaly without an apparent increase in skeletal growth. In addition, expression of the endogenous GH and IGF-I genes is inhibited. These results are consistent with IGF-I playing an important role in the control of somatic growth.
Mathews
L S
LS
Department of Biochemistry, University of Washington, Seattle 98195.
Hammer
R E
RE
Behringer
R R
RR
D'Ercole
A J
AJ
Bell
G I
GI
Brinster
R L
RL
Palmiter
R D
RD
D000818:Animals; D001846:Bone Development; D004274:DNA, Recombinant; D005260:Female; D005786:Gene Expression Regulation; D006128:Growth; D013006:Growth Hormone / Q000235:genetics; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics* / Q000502:physiology; D008297:Male; D008668:Metallothionein / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes; D009929:Organ Size; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D013002:Somatomedins / Q000235:genetics*; D014158:Transcription, Genetic; D015430:Weight Gain
D004274:DNA, Recombinant; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D008668:Metallothionein