Expression of messenger RNAs encoding insulin-like growth factor-I, -II, and insulin-like growth factor binding protein-2 in bovine endometrium during the estrous cycle and early pregnancy.
The present study characterized the changes in concentrations of insulin-like growth factors-I and -II (IGF-I and IGF-II) in uterine luminal flushings, and the endometrial mRNA levels of IGF-I, IGF-II, and IGF binding protein-2 (IGFBP-2) obtained from Days 0 through 18 of the bovine estrous cycle and early pregnancy. Concentrations of IGF-I and IGF-II in uterine flushings were greater on Days 0 and 5 than on other days of the estrous cycle or pregnancy. Northern blot analysis of endometrial poly(A)+ RNA revealed two major transcripts of 7.5 and 1.0 Kb for IGF-I, one major transcript of 4.0 Kb for IGF-II, and one major transcript of 1.3 Kb for IGFBP-2. RNA dot-blot analyses indicated that endometrial expression of IGF-I mRNA was unaffected by day of the estrous cycle or status (cyclic vs. pregnancy). However, endometrial expression of IGF-II mRNA was greater in pregnant than in cyclic endometrium on Days 15 and 18. Levels of endometrial IGFBP-2 mRNA increased (p less than 0.05) between Days 10 and 18 of the estrous cycle and early pregnancy. Results suggest that the presence of the bovine conceptus has a stimulatory effect on endometrial expression levels of IGF-II, whereas progesterone appears to be involved with enhancement of IGFBP-2.
Geisert
R D
RD
Oklahoma Agricultural Experiment Station, Oklahoma State University, Stillwater 74078.
Lee
C Y
CY
Simmen
F A
FA
Zavy
M T
MT
Fliss
A E
AE
Bazer
F W
FW
Simmen
R C
RC
D000818:Animals; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000235:genetics*; D002417:Cattle / Q000378:metabolism*; D004717:Endometrium / Q000378:metabolism*; D004971:Estrus / Q000502:physiology; D005260:Female; D015870:Gene Expression; D018971:Insulin-Like Growth Factor Binding Protein 2; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism*; D014158:Transcription, Genetic
D002352:Carrier Proteins; D018971:Insulin-Like Growth Factor Binding Protein 2; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II