Expression of transforming growth factor-beta (TGF-beta 1) and insulin-like growth factor II (IGF-II) messenger RNA in the developing subcutaneous tissue (SQ) of the fetal pig.
Studies (in situ hybridization) were performed on the developing subcutaneous tissue (SQ) of the pig fetus to determine sites of synthesis of TGF-beta 1 and IGF-II. Tissues from 50, 70, 90, 110-day-old pig fetuses and 7-day-old postnatal pigs were Bouin's fixed, paraffin embedded and hybridized with biotin labelled cDNA probes. The expression of TGF-beta 1 messenger RNA was detectable primarily in the dermis, hair follicle fat lobule, outer and inner SQ areas at all ages. Cells adjacent to adipocyte clusters and some small adipocytes were positive for TGF-beta 1. There was no positive hybridization of TGF-beta 1 probes in the developing muscle below the SQ. The expression of IGF-II was evident in the developing muscle below the SQ at 50 d and 70 d, and could be detected in the outer and inner SQ at 70 d. Much lower levels of IGF-II expression were observed in 90 and 110 d fetuses, but an increase in IGF-II expression was evident in the muscle of 7d postnatal pigs. Our results suggest that paracrine and autocrine regulatory systems may be operative for developing adipocytes (TGF-beta 1) and muscle (IGF-II), with specific areas and times of TGF-beta 1 and IGF-II expression being evident in developing pig SQ tissue.
Richardson
R L
RL
Richard B. Russell Agriculture Research Center, USDA, Athens, GA 30613.
Wright
J T
JT
Kim
J W
JW
Hausman
G J
GJ
D000818:Animals; D015152:Blotting, Northern; D005333:Fetus / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D015870:Gene Expression; D007150:Immunohistochemistry; D007335:Insulin-Like Growth Factor II / Q000235:genetics* / Q000378:metabolism; D009132:Muscles / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics; D012867:Skin / Q000737:chemistry* / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D013552:Swine; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D007335:Insulin-Like Growth Factor II