Characterization of the porcine FSCN3 gene: cDNA cloning, genomic structure, mapping and polymorphisms

Identification of hub genes associated with spermatogenesis by bioinformatics analysis

Spermatogenesis is a complex process related to male infertility. Till now, the critical genes and specific mechanisms have not been elucidated clearly. Our objective was to determine the hub genes that play a crucial role in spermatogenesis by analyzing the differentially expressed genes (DEGs) present in non-obstructive azoospermia (NOA) compared to OA and normal samples using bioinformatics analysis. Four datasets, namely GSE45885, GSE45887, GSE9210 and GSE145467 were used. Functional enrichment analyses were performed on the DEGs. Hub genes were identified based on protein-protein interactions between DEGs. The expression of the hub genes was further examined in the testicular germ cell tumors from the TCGA by the GEPIA and validated by qRT-PCR in the testes of lipopolysaccharide-induced acute orchitis mice with impaired spermatogenesis. A total of 203 DEGs including 34 up-regulated and 169 down-regulated were identified. Functional enrichment analysis showed DEGs were mainly involved in microtubule motility, the process of cell growth and protein transport. PRM2, TEKT2, FSCN3, UBQLN3, SPATS1 and GTSF1L were identified and validated as hub genes for spermatogenesis. Three of them (PRM2, FSCN3 and TEKT2) were significantly down-regulated in the testicular germ cell tumors and their methylation levels were associated with the pathogenesis. In summary, the hub genes identified may be related to spermatogenesis and may act as potential therapeutic targets for NOA and testicular germ cell tumors.

Testis-specific fascin component FSCN3 is dispensable for mouse spermatogenesis and fertility

BACKGROUND

Fascins belong to a family of actin-bundling proteins that are involved in a wide range of biological functions. FSCN3, a newly identified testis-specific actin-bundling protein, is specifically expressed in elongated spermatids. However, its in vivo function in mouse spermiogenesis remains unknown.

METHODS AND RESULTS

We generated Fscn3 knockout mice through CRISPR/Cas9 gene-editing technology. Fscn3^-/- mice displayed normal testis morphology and testis to bodyweight ratio, and sperm concentrations did not differ significantly between Fscn3^+/+ and Fscn3^-/- mice. Fertility assays consistently revealed that Fscn3^-/- mice are completely fertile and their reproductive status does not differ from that of wild-type. Moreover, hematoxylin and eosin staining of the testis sections of Fscn3^-/- mice detected various germ cells, ranging from spermatogonia to mature spermatozoa. Furthermore, the swimming velocity of the sperm of Fscn3^-/- mice was comparable to that of their wild-type littermates. Both Fscn3^+/+ and Fscn3^-/-mice had normal sperm morphology, indicating that the disruption of Fscn3 does not affect sperm morphology. The analysis of meiotic prophase I progression demonstrated normal prophase-I phases (leptonema to diplonema) in both Fscn3^+/+ and Fscn3^-/- mice, suggesting that Fscn3 is not essential for meiosis I.

CONCLUSION

Our study provides the first evidence that FSCN3 is a testis-specific actin-bundling protein that is not required for mouse spermatogenesis. Our results will help reproductive biologists focus their efforts on genes that are crucial for fertility and avoid research duplication.

Identification of candidate genes in regulation of spermatogenesis in sheep testis following dietary vitamin E supplementation

Dietary vitamin E supplementation is beneficial to semen quality in different sheep and goat breeds. The aim of this research was to further investigate the effect of vitamin E in sheep on spermatogenesis and its regulatory mechanisms using RNA-seq. Thirty male Hu lambs were randomly divided into three groups. The animals received 0, 200 or 2000 IU/day vitamin E dietary supplementation for 105 days, and its effects were subsequently evaluated. The results indicate vitamin E supplementation increased the number of germ cells in the testes and epididymides. The positive effects were reduced, however, in animals that received 2000 IU/d vitamin E. Using the RNA-seq procedure, there was detection of a number of differentially expressed genes such as NDRG1, FSCN3 and CYP26B1 with these genes being mainly related to the regulation of spermatogenesis. Supplementation with 2000 IU/d vitamin E supplementation resulted in a lesser abundance of skeleton-related transcripts such as TUBB, VIM and different subtypes of collagen, and there was also an effect on the ECM-receptor interaction pathway. These changes appear to be responsible for the lesser beneficial effect of the greater vitamin E concentrations. The results provide a novel insight into the regulation of spermatogenesis by vitamin E at the molecular level, however, for a precise understanding of functions of the affected genes there needs to be further study.

Fascin - An actin binding and bundling protein in the testis and its role in ectoplasmic specialization dynamics

In the mammalian testis such as in rats, a unique actin-rich cell-cell adherens junction (AJ) known as ectoplasmic specialization (ES) is found in the seminiferous epithelium. ES is conspicuously found between Sertoli cells near the basement membrane known as the basal ES, which together with tight junction (TJ), gap junction, and desmosome constitute the blood-testis barrier (BTB). The BTB, in turn, anatomically divides the seminiferous epithelium into the basal and the adluminal (apical) compartment. On the other hand, ES is also found at the Sertoli-spermatid interface known as apical ES which is the only anchoring device for developing step 8-19 spermatids during spermiogenesis. One of the most typical features of the ES is the array of actin microfilament bundles that lie perpendicular to the Sertoli cell plasma membrane and are sandwiched in-between the cisternae of endoplasmic reticulum and the Sertoli cell plasma membrane. While these actin filament bundles confer the adhesive strength of Sertoli cells at the BTB and also spermatids in the adluminal compartment, they must be rapidly re-organized from their bundled to unbundled/branched configuration and vice versa to provide plasticity to the ES so that preleptotene spermatocytes and spermatids can be transported across the immunological barrier and the adluminal compartment, respectively, during the epithelial cycle of spermatogenesis. Fascin is a family of actin microfilament cross-linking and bundling proteins that is known to confer bundling of parallel actin microfilaments in mammalian cells. A recent report has illustrated the significance of a fascin protein called fascin 1 in actin microfilaments at the ES, pertinent to its role in spermatogenesis (Gungor-Ordueri et al. Am J Physiol Endocrinol Metab 307, E738-753, 2004 (DOI:10.1152/ajpendo.00113.2014). In this Commentary, we critically evaluate these findings in light of the role of fascin in other mammalian cells, providing some insightful information for future investigations.

Potential biomarkers of nonobstructive azoospermia identified in microarray gene expression analysis

OBJECTIVE

To identify potential biomarkers of azoospermia to determine a particular stage of spermatogenetic differentiation.

DESIGN

GeneChip Human Gene 1.0 ST microarray with validation at mRNA and protein levels.

SETTING

Basic research laboratory.

PATIENT(S)

Men with various types of nonobstructive azoospermia (n = 18) and with normal spermatogenesis (n = 4).

INTERVENTION(S)

Obtaining 31 testicular biopsy samples.

MAIN OUTCOME MEASURE(S)

Gene expression analysis using the Affymetrix Human Gene 1.0 ST microarrays on 14 selected genes according to the highest fold change, verified with quantitative polymerase chain reaction and on independent set of microarray samples. Western blot and immunohistochemistry were additionally performed.

RESULT(S)

The comparative analysis of gene expression profiles in the infertile and control groups resulted in the selection of 4,946 differentially expressed genes. AKAP4, UBQLN3, CAPN11, GGN, SPACA4, SPATA3, and FAM71F1 were the most significantly down-regulated genes in infertile patients. Global analysis also led to identification of up-regulated genes-WBSCR28, ADCY10, TMEM225, SPATS1, FSCN3, GTSF1L, and GSG1-in men with late maturation arrest. Moreover, the results from quantitative polymerase chain reaction and Western blot largely confirmed the microarray data.

CONCLUSION(S)

The set of selected genes can be used to create a molecular diagnostic tool to determine the degree of spermatogenic impairment for men with idiopathic nonobstructive azoospermia.

Activation of rye 5RL neocentromere by an organophosphate pesticide

An interstitial constriction located on the long arm of rye chromosome 5R (5RL) shows neocentromeric activity at meiosis. In some meiocytes this region is strongly stretched orienting with the true centromere to opposite poles at metaphase I, and keeping sister chromatid cohesion at anaphase I. We found previously that the frequency of neocentric activity varied dramatically in different generations suggesting the effect of environmental factors. Here we studied the behavior of the 5RL neocentromere in mono- and ditelosomic 5RL, and mono-, and disomic 5R wheat-rye addition lines, untreated and treated with an organophosphate pesticide. The treated plants form neocentromeres with an about 4.5-fold increased frequency compared to untreated ones, demonstrating that the pesticide promotes neocentric activity. The neocentromere was activated irrespectively of the pairing configuration or the presence of a complete or truncated 5R centromere. Fluorescence in situ hybridization (FISH) with 2 repetitive sequences (UCM600 and pSc119.2) present at the constriction showed kinetic activity at several locations within this region. Immunostaining with anti-α-tubulin showed that treated plants have abnormal spindles in 46% of the metaphase I cells, indicating that disturbances in spindle formation might promote neocentromere activation.