Change in hepatic and plasma bile acid contents and its regulatory gene expression in the chicken embryo.
To investigate changes in bile acid biosynthesis in chicken (Gallus gallus) during embryonic stages, we studied the contribution of hepatic and plasma total bile acid levels, mRNA expression of cholesterol 7 alpha-hydroxylase (CYP7A1), and the expression of its regulatory genes in two embryo models (i.e., broilers and layers) differing in lipid metabolism. Total bile acid levels in plasma and liver were low during embryonic stages, as well as expression of CYP7A1. At hatch (P0), hepatic and plasma total bile acid levels and CYP7A1 mRNA expression in liver were markedly increased in both models. The hepatic mRNA expression of liver X receptor (LXR)alpha, a regulator of CYP7A1 gene expression gradually decreased with developmental stages of both broilers and layers. The hepatic mRNA expression of farnesoid X receptor (FXR), a repressor of CYP7A1 gene expression, also decreased with embryonic development. The present results showed that the mRNA expression of CYP7A1 and synthesis of bile acids was low in embryonic stages, suggesting that FXR might be a key regulator of CYP7A1 gene expression in the chicken embryo.
Sato
Momoka
M
Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan.
Sato
Kan
K
Furuse
Mitsuhiro
M
D000818:Animals; D001647:Bile Acids and Salts / Q000097:blood / Q000378:metabolism*; D002642:Chick Embryo; D002790:Cholesterol 7-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D008099:Liver / Q000196:embryology* / Q000378:metabolism*; D000071518:Liver X Receptors; D057093:Orphan Nuclear Receptors; D012333:RNA, Messenger / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D051779:Sterol Regulatory Element Binding Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000099150:Receptor, Farnesoid X-Activated
D001647:Bile Acids and Salts; D002790:Cholesterol 7-alpha-Hydroxylase; D004268:DNA-Binding Proteins; D000071518:Liver X Receptors; D057093:Orphan Nuclear Receptors; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D051779:Sterol Regulatory Element Binding Proteins; D014157:Transcription Factors; D000099150:Receptor, Farnesoid X-Activated