Volume 10, Issue 4 (July 2008) 10, 569–576; 10.1111/j.1745-7262.2008.00408.x
Expression of the retinoic acid-metabolizing enzymes RALDH2 and CYP26b1 during mouse postnatal testis development
Jing-Wen Wu1,2, Ru-Yao Wang1,2, Qiang-Su Guo1,2 and Chen Xu1,2
1 Department of Histology and Embryology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
2 Shanghai Key Laboratory for Reproductive Medicine, Shanghai 200025, China
Correspondence: Dr Chen Xu, Department of Histology and Embryology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China. Fax: +86-21-6466-3160. E-mail: email@example.com
Received 21 October 2007; Accepted 6 March 2008.
Aim: To study the expression pattern of the retinoic acid metabolizing enzymes RALDH2 and CYP26b1 during mouse postnatal testis development at both mRNA and protein levels.
Methods: Real-time polymerase chain reaction and Western blot analysis were performed to determine the relative quantity of RALDH2 and CYP26b1 at both mRNA and protein levels at postnatal day 1, 5, 10, 20, and in adult mice (70 days testes). Testicular localization of RALDH2 and CYP26b1 during mouse postnatal development was examined using immunohistochemistry assay.
Results: Aldh1a2 transcripts and its protein RALDH2 began to increase at postnatal day 10, and remained at a high level through postnatal day 20 to adulthood. Cyp26b1 transcripts and CYP26b1 protein did not change significantly during mouse postnatal testis development. RALDH2 was undetectable in the postnatal 1, 5 and 10 day testes using immunohis-tochemistry assay. At postnatal day 20 it was detected in pachytene spermatocytes. Robust expression of RALDH2 was restricted in round spermatids in the adult mouse testis. In the developing and adult testis, CYP26b1 protein was confined to the peritubular myoepithelial cells.
Conclusion: Our results indicate that following birth, the level of retinoic acid in the seminiferous tubules might begin to increase at postnatal day 10, and maintain a high level through postnatal day 20 to adulthood.
Keywords: RALDH2, CYP26b1, retinoic acid, spermatogenesis, testis
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