Altered gene expression during rat Wolffian duct development in response to in utero exposure to the antiandrogen linuron.
Linuron is an herbicide with weak androgen receptor (AR) antagonist activity. Exposure to linuron from gestation days (GD) 12 to 21 perturbs androgen-dependent male reproductive development. In utero exposure to 50-mg/kg/day linuron induces malformations of the epididymis and the vas deferens. The objective of this study was to identify alterations in gene expression within the testis and epididymis associated with abnormal Wolffian duct development and to correlate changes in gene expression with the gross morphology of the affected epididymides. Pregnant Sprague-Dawley rats were administered either corn oil vehicle or linuron (50 mg/kg/day) by gavage from GD 12 to 21 (n = 3-6 controls, n = 5-10 linuron-treated dams per time point). Changes in gene expression were evaluated in testes on GD 21 and in epididymides on GD 21 and postnatal day (PND) 7, using cDNA microarrays and confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) analyses. RNA was isolated from intact epididymides with reduced or no ductal coiling from the linuron groups, and epididymides with noncontiguous ducts were excluded. In the fetal testis, exposure to linuron did not result in reduced mRNA expression of the AR or that of several steroidogenic enzymes, supporting the hypothesis that linuron does not reduce fetal testosterone production. Linuron induced a significant decrease in AR mRNA expression in GD 21 epididymides. Significant changes in mRNA expression in GD 21 and PND 7 epididymides were also identified in the epidermal growth factor (EGF), insulin-like growth factor 1 (IGF-1), bone morphogenetic protein (BMP), fibroblast growth factor (FGF), and Notch signaling pathways. These pathways are involved in tissue morphogenesis. Changes in the expression of AR and IGF-1 receptors were detected by immunostaining in malformed epididymides from linuron-exposed rats. Linuron induced changes in epididymal gene expression suggestive of altered paracrine interactions between the mesenchyme and epithelial cells during development. The EGF, Notch, IGF-1, BMP4, and FGF signaling pathways may be involved in normal testosterone-mediated development of the Wolffian duct.
CIIT Centers for Health Research, Research Triangle Park, North Carolina 27709-2137, USA. katie_turner@merck.com
Katie J
KJ
Turner
Barry S
BS
McIntyre
Suzanne L
SL
Phillips
Norman J
NJ
Barlow
Christopher J
CJ
Bowman
Paul M D
PM
Foster
D000818:Animals; D000831:Animals, Newborn; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis; D004822:Epididymis / Q000187:drug effects / Q000196:embryology / Q000378:metabolism; D004965:Estrogen Antagonists / Q000633:toxicity*; D005260:Female; D005333:Fetus / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis; D015870:Gene Expression / Q000187:drug effects*; D019812:Heparan Sulfate Proteoglycans / Q000096:biosynthesis; D006540:Herbicides / Q000633:toxicity*; D007150:Immunohistochemistry; D008044:Linuron / Q000633:toxicity*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017526:Receptor, IGF Type 1 / Q000096:biosynthesis / Q000235:genetics; D051883:Receptor, Notch2; D011944:Receptors, Androgen / Q000096:biosynthesis / Q000235:genetics; D011956:Receptors, Cell Surface / Q000096:biosynthesis; D017465:Receptors, Opioid, delta / Q000096:biosynthesis; D012098:Reproduction / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013737:Testis / Q000187:drug effects / Q000196:embryology / Q000378:metabolism; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000096:biosynthesis; D014928:Wolffian Ducts / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism*
C525811:Bmp4 protein, rat; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D004965:Estrogen Antagonists; D019812:Heparan Sulfate Proteoglycans; D006540:Herbicides; C497766:Notch2 protein, rat; D012333:RNA, Messenger; D051883:Receptor, Notch2; D011944:Receptors, Androgen; D011956:Receptors, Cell Surface; D017465:Receptors, Opioid, delta; D019717:Tissue Inhibitor of Metalloproteinase-3; D008044:Linuron; D016222:Fibroblast Growth Factor 2; D017526:Receptor, IGF Type 1