|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The Population Council,3
Rockefeller University,4 New York, New York 10021
Division of Reproductive Biology,5 Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
The postnatal development of Leydig cells can be divided into three distinct stages: initially they exist as fibroblast-like progenitor Leydig cells (PLCs) appearing in the testis by Days 1421; subsequently, by Day 35, they become immature Leydig cells (ILCs) acquiring steroidogenic organelle structure and enzyme activities but metabolizing most of the testosterone they produce; finally, as adult Leydig cells (ALCs) by Day 90, they actively produce testosterone. The factors controlling proliferation and differentiation of Leydig cells remain largely unknown, and the aim of the present study was to identify changes in gene expression during development through cDNA array analysis of PLCs, ILCs, and ALCs. By cluster analysis, it was determined that the transitions from PLC to ILC to ALC were associated with downregulation of mRNAs corresponding to 107 genes. The downregulated genes included cell-cycle regulators, e.g., cyclin D1 (Ccnd1); growth factors, e.g., basic fibroblast growth factor (Fgf2); growth-factor-related receptors, e.g., platelet-derived growth factor
receptor (Pdgfra); oncogenes, e.g., kit oncogene (Kit); and transcription factors, e.g., early growth response 1 (Egr1). Conversely, expression levels of 264 genes were increased by at least twofold. Most of these were related to differentiated function and included steroidogenic enzymes, e.g., 11ß-hydroxysteroid dehydrogenase 2 (Hsd11b2); neurotransmitter receptors, e.g., acetylcholine receptor nicotinic
4 (Chrna4); stress response factors, e.g., glutathione transferase 8 (Gsta4); and protein turnover enzymes, e.g., tissue inhibitor of metalloproteinase 2 (Timp2). The detection of Hsd11b2 mRNA in the array was the first indication that this gene is expressed in Leydig cells, and parallel increases in Hsd11b2 mRNA and enzyme activity were recorded. Thus, gene profiling demonstrates that postnatal development is associated with changes in the expression levels of several different clusters of genes consistent with the processes of Leydig cell growth and differentiation.
developmental biology, gene regulation, Leydig cells, luteinizing hormone, steroid hormone receptors
2 Correspondence: Matthew P. Hardy, The Population Council, 1230 York Ave., New York, NY 10021. FAX: 212 327 7678; m-hardy{at}popcbr.rockefeller.edu
This article has been cited by other articles:
![]() |
IN MEMORIAM Matthew P. Hardy, Ph.D. 1957-2007 Biol Reprod, March 1, 2008; 78(3): 563 - 564. [Full Text] [PDF] |
||||
![]() |
P. J. O'Shaughnessy, P. J. Baker, A. Monteiro, S. Cassie, S. Bhattacharya, and P. A. Fowler Developmental Changes in Human Fetal Testicular Cell Numbers and Messenger Ribonucleic Acid Levels during the Second Trimester J. Clin. Endocrinol. Metab., December 1, 2007; 92(12): 4792 - 4801. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. J Teerds, E. Rijntjes, M. B Veldhuizen-Tsoerkan, F. F G Rommerts, and M. de Boer-Brouwer The development of rat Leydig cell progenitors in vitro: how essential is luteinising hormone? J. Endocrinol., September 1, 2007; 194(3): 579 - 593. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Fombonne, C. Charrier, I. Goddard, E. Moyse, and S. Krantic Leptin-Mediated Decrease of Cyclin A2 and Increase of Cyclin D1 Expression: Relevance for the Control of Prepubertal Rat Leydig Cell Division and Differentiation Endocrinology, May 1, 2007; 148(5): 2126 - 2137. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. He, W.-Y. Chan, and M. Dym Microarray technology offers a novel tool for the diagnosis and identification of therapeutic targets for male infertility Reproduction, July 1, 2006; 132(1): 11 - 19. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. D. Veldhuis, J. N. Roemmich, E. J. Richmond, and C. Y. Bowers Somatotropic and Gonadotropic Axes Linkages in Infancy, Childhood, and the Puberty-Adult Transition Endocr. Rev., April 1, 2006; 27(2): 101 - 140. [Abstract] [Full Text] [PDF] |
||||
![]() |
R.-S. Ge, Q. Dong, C. M. Sottas, V. Papadopoulos, B. R. Zirkin, and M. P. Hardy In search of rat stem Leydig cells: Identification, isolation, and lineage-specific development PNAS, February 21, 2006; 103(8): 2719 - 2724. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |