Retinoic acid receptor alpha gene expression in the rat testis: potential role during the prophase of meiosis and in the transition from round to elongating spermatids

• Published in: Biology of reproduction Vol. 56; no. 2; pp. 549 - 556
• Main Authors: Akmal, K.M. (Washington State University, Pullman, WA.), Dufour, J.M, Kim, K.H
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01.02.1997
• Subjects: Aging; Animals; ARN MENSAJERO; ARN MESSAGER; Biological and medical sciences; Blotting, Northern; Cell Nucleus - chemistry; CHIMIORECEPTEUR; ESPERMATOGENESIS; ESPERMATOZOO; EXPRESION GENICA; EXPRESSION DES GENES; Fundamental and applied biological sciences. Psychology; GENE; Gene Expression; GENES; Immunohistochemistry; In Situ Hybridization; Male; Mammalian male genital system; MEIOSE; MEIOSIS; Meiosis - physiology; Morphology. Physiology; Prophase - physiology; QUIMIORECEPTORES; RAT; RATA; Rats; Rats, Sprague-Dawley; Receptors, Retinoic Acid - analysis; Receptors, Retinoic Acid - genetics; RETINOL; RNA, Messenger - analysis; Spermatids - cytology; SPERMATOGENESE; Spermatogenesis; SPERMATOZOIDE; TESTICULE; TESTICULOS; Testis - growth & development; Testis - metabolism; Vertebrates: reproduction; Rat; Spermatogenesis; Rodentia; Vitamin; Male; Meiosis; Retinoids; Germinal cell; Gene expression; Testicle; Male genital system; Spermatid; Retinol; Vertebrata; Specificity; Mammalia; Target cell; Cell; Retinoic acid; Biological receptor
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod56.2.549

Mutational studies have identified retinoic acid receptor (RARalpha) as having an essential role in spermatogenesis. The objective of this study was to determine which cells express RARalpha within the normal rat testis by conducting in situ analyses for mRNA and protein. Characterization of RARalpha expression revealed the time and location of the vitamin A requirement during spermatogenesis. In situ hybridization analysis of testis from adult rats showed the highest level of transcripts occurring in round spermatids at stage VIII of the spermatogenic cycle. Analysis in the developing testes revealed that the mRNA level was high from 10 to 15 days of age, both in Sertoli cells and in germ cells, and then declined in 20-day-old rats. Consistent with this, immunohistochemical studies on adult testis demonstrated that the protein was present in the nucleus of the elongating spermatids (stages IX-XI) but not in elongated spermatids. The protein was also expressed in germ cells in the prophase of meiosis and at very low levels in Sertoli cells. These results suggest a role for RARalpha during meiosis, at the transition from round to elongating spermatids, and in Sertoli cells of developing testis