Chicken 11beta-hydroxysteroid dehydrogenase type 2: partial cloning and tissue distribution.

Area of Science:

• Molecular biology
• Biochemistry
• Endocrinology

Background:

• NAD(+)-dependent 11beta-hydroxysteroid dehydrogenase type 2 (11HSD2) is vital for inactivating glucocorticoids, preventing corticosteroid receptor overactivation.
• Understanding 11HSD2 function is key to comprehending steroid hormone regulation in vertebrates.

Purpose of the Study:

• To partially clone and characterize the chicken 11HSD2 enzyme.
• To determine the tissue distribution of chicken 11HSD2 mRNA and its enzymatic activity.

Main Methods:

• Partial cDNA cloning of chicken 11HSD2 from kidney mRNA using reverse transcription and PCR.
• Sequence homology analysis with mammalian and fish 11HSD2.
• Analysis of tissue expression patterns for 11HSD2 mRNA and NAD(+)-dependent 11beta-oxidase activity.

Main Results:

• A 991bp cDNA sequence for chicken 11HSD2 was successfully cloned, showing 56-59% homology to mammalian and 46-48% to fish counterparts.
• Conserved motifs of the short-chain dehydrogenase/reductase superfamily were identified within the cloned cDNA.
• Chicken 11HSD2 mRNA expression and enzyme activity exhibited similar tissue distribution, with high levels in kidney, small intestine, colon, and oviduct, and low levels in ovary, brain, liver, and testis.

Conclusions:

• The study successfully cloned and characterized chicken 11HSD2, providing insights into its molecular structure and conserved functional motifs.
• The tissue distribution analysis highlights the enzyme's significant role in the kidney, digestive system, and oviduct of chickens.
• These findings contribute to the understanding of glucocorticoid metabolism and regulation in avian species.