Fold-change correction values for testicular somatic transcripts in gene expression studies of human spermatogenesis.

Study Question: What are the reference values for delineating altered somatic cell gene expression from transcript enrichment/dilution in gene expression studies of human spermatogenesis?

Summary Answer: We have designed a crosstable and rule-of-thumb values for different stages of spermatogenic impairment that define the reference cut-off values for altered gene expression in Sertoli and Leydig cells in the context of impaired spermatogenesis.

What Is Known Already: Morphometrical studies have shown that on the cellular level, impaired spermatogenesis results in a relative enrichment of somatic cell types. However, until now it is not known how this affects transcript levels in gene expression studies.

Global human tissue profiling and protein network analysis reveals distinct levels of transcriptional germline-specificity and identifies target genes for male infertility.

Background: Mammalian spermatogenesis is a process that involves a complex expression program in both somatic and germ cells present in the male gonad. A number of studies have attempted to define the transcriptome of male meiosis and gametogenesis in rodents and primates. Few human transcripts, however, have been associated with testicular somatic cells and germ cells at different post-natal developmental stages and little is known about their level of germline-specificity compared with non-testicular tissues.

Screening for biomarkers of spermatogonia within the human testis: a whole genome approach.

Background: A key step in studying the biology of spermatogonia is to determine their global gene expression profile. However, disassociation of these cells from the testis may alter their profile to a considerable degree. To characterize the molecular phenotype of human spermatogonia, including spermatogonial stem cells (SSCs), within their cognate microenvironment, a rare subtype of human defective spermatogenesis was exploited in which spermatogonia were the only germ cell type.

Highly accurate sigmoidal fitting of real-time PCR data by introducing a parameter for asymmetry.

Background: Fitting four-parameter sigmoidal models is one of the methods established in the analysis of quantitative real-time PCR (qPCR) data. We had observed that these models are not optimal in the fitting outcome due to the inherent constraint of symmetry around the point of inflection. Thus, we found it necessary to employ a mathematical algorithm that circumvents this problem and which utilizes an additional parameter for accommodating asymmetrical structures in sigmoidal qPCR data.

Cross-platform gene expression signature of human spermatogenic failure reveals inflammatory-like response.

Background: The molecular basis of human testicular dysfunction is largely unknown. Global gene expression profiling of testicular biopsies might reveal an expression signature of spermatogenic failure in azoospermic men.

Methods: Sixty-nine individual testicular biopsy samples were analysed on two microarray platforms; selected genes were validated by quantitative real-time PCR and immunohistochemistry.

Immortalized Sertoli cell lines sk11 and sk9 and binding of spermatids in vitro.

Aim: To determine the effectiveness of the sk11, sk9 and sk11 TNUA5 Sertoli cell lines in binding germ cells in vitro.

Methods: The immortalized Sertoli cell lines sk9, sk11 and sk11 TNUA5 were used in co-culture experiments with germ cells in media with or without reproductive hormones and incubated for 44 h at 32 degrees . The number of germ cells bound to Sertoli cells was then determined and statistically analyzed.