Effects of FSH on testicular transcript levels . M H ABEL and others 299 Figure 4 Real-time PCR measurements of germ cell-speciﬁc mRNA transcript levels in testes from adult hpg mice treated for 0 (control), 12, 24 or 72 h with FSH. Results show the meanGS.E.M. of three or four animals per group. Groups with different letter superscripts are signiﬁcantly different; where no superscripts are shown there was no difference between groups. up-regulated more than twofold at all times indicating that there was a changing pattern of expression as the exposure to FSH was maintained. There were also 63 transcripts down-regulated more than twofold at all times suggesting that the inhibitory effects of FSH are more consistent. Results from the arrays and from real- time PCR showed that FSH treatment caused a general increase in many transcripts encoding known Sertoli cell-speciﬁc products such as Tesc, Lgals1, Fabp5 and Aqp5 (Kingma et al. 1998, Perera et al. 2001, Dettin et al. 2003) although some transcripts (e.g. Shbg, Tjp1 (Wang et al. 1989, Byers et al. 1991)) were unaffected while others were decreased (see below) indicating that the effect of FSH was not simply to increase the overall activity of the cells. Comparison of the up-regulated transcripts in this study with the list of Sertoli cell transcripts generated by Chalmel et al. (2007) conﬁrms that, at least initially, a high proportion of the affected transcripts are likely to be of Sertoli cell origin. The declining proportion of Sertoli cell transcripts at later times is likely to be due to increasing activity in other cells such as the Leydig cell. The lower proportion of down-regulated transcripts that match to the Sertoli cell list of Chalmel et al. (2007) may reﬂect the GeneChip sensitivity involved in generating that list since many of these down-regulated transcripts might be expected to have a low level of expression in the normal animal. Among the transcripts that showed decreased levels in response to FSH were a number encoding tight junction components. This is consistent with a recent Figure 5 Real-time PCR measurements of mRNA transcript levels of species with unknown testicular origin. Levels were measured in testes from adult hpg mice treated for 0 (control), 12, 24 or 72 h with FSH. Results show the meanGS.E.M. of three or four animals per group. Groups with different letter superscripts are signiﬁcantly different. www.endocrinology-journals.org Journal of Molecular Endocrinology (2009) 42, 291–303