328. CLAUDIN-8 IS EXPRESSED IN BOVINE TESTIS GERM CELLS

2010 ◽  
Vol 22 (9) ◽  
pp. 128
Author(s):  
M. Rookledge ◽  
M. Colgrave ◽  
S. Stockwell ◽  
S. Schmoelzl

Germline stem cells in the testis allow for the continued production of spermatozoa throughout a male’s life. These cells are capable of self-renewal and have the ability to colonise testis tissue and give rise to spermatocytes after transplantation. Identification of germ cells and other cell types within testis tissue is important for increasing understanding of germ cell biology. Work in this lab is focused on the bovine testis, and we use both germ and non-germ cell markers for cell identification and germ cell enrichment. Such markers are also used for monitoring physiological and pathological changes in testis tissue after treatments such as irradiation. At present cell type markers for germ cells are limited, particularly in livestock species. This study has therefore investigated candidate marker genes for expression in testis cells. Here, we present quantitative gene expression data for Claudin-8 (CLDN8) in testis tissue. Claudin-8 is a membrane protein involved in the formation of tight junctions, such as are formed by germ cells in the testis. We used qRT-PCR to examine the expression of CLDN8 and other candidate genes in germ cell enriched and non-enriched testis cell fractions. Our qRT-PCR analysis shows that CLDN8 is preferentially expressed in germ cell enriched fractions. Testis cell fractions were also analysed for expression of established germ cell markers such as PLZF (ZBTB16) and VASA (DDX4), as well as for Sertoli cell marker GATA4. Our analysis shows a positive correlation between expression of CLDN8 and established germ cell markers, and a negative correlation between expression of CLDN8 and established Sertoli cells markers.

Reproduction ◽  
2009 ◽  
Vol 138 (4) ◽  
pp. 667-677 ◽  
Author(s):  
Kyle C Caires ◽  
Jeanene de Avila ◽  
Derek J McLean

Vascular endothelial growth factor-A (VEGFA) is a hypoxia-inducible peptide essential for angiogenesis and targets nonvascular cells in a variety of tissues and cell types. The objective of the current study was to determine the function of VEGF during testis development in bulls. We used an explant tissue culture and treatment approach to test the hypothesis that VEGFA-164 could regulate the biological activity of bovine germ cells. We demonstrate that VEGFA, KDR, and FLT1 proteins are expressed in germ and somatic cells in the bovine testis. Treatment of bovine testis tissue with VEGFA in vitro resulted in significantly more germ cells following 5 days of culture when compared with controls. Quantitative real-time RT-PCR analysis determined that VEGF treatment stimulated an intracellular response that prevents germ cell death in bovine testis tissue explants, as indicated by increased expression of BCL2 relative to BAX and decreased expression of BNIP3 at 3, 6, and 24 h during culture. Blocking VEGF activity in vitro using antisera against KDR and VEGF significantly reduced the number of germ cells in VEGF-treated testis tissue to control levels at 120 h. Testis grafting provided in vivo evidence that bovine testis tissue treated with VEGFA for 5 days in culture contained significantly more differentiating germ cells compared with controls. These findings support the conclusion that VEGF supports germ cell survival and sperm production in bulls.


Reproduction ◽  
2010 ◽  
Vol 140 (5) ◽  
pp. 733-742 ◽  
Author(s):  
S Albert ◽  
J Ehmcke ◽  
J Wistuba ◽  
K Eildermann ◽  
R Behr ◽  
...  

The seminiferous epithelium in the nonhuman primate Callithrix jacchus is similarly organized to man. This monkey has therefore been used as a preclinical model for spermatogenesis and testicular stem cell physiology. However, little is known about the developmental dynamics of germ cells in the postnatal primate testis. In this study, we analyzed testes of newborn, 8-week-old, and adult marmosets employing immunohistochemistry using pluripotent stem cell and germ cell markers DDX4 (VASA), POU5F1 (OCT3/4), and TFAP2C (AP-2γ). Stereological and morphometric techniques were applied for quantitative analysis of germ cell populations and testicular histological changes. Quantitative RT-PCR (qRT-PCR) of testicular mRNA was applied using 16 marker genes establishing the corresponding profiles during postnatal testicular development. Testis size increased during the first 8 weeks of life with the main driver being longitudinal outgrowth of seminiferous cords. The number of DDX4-positive cells per testis doubled between birth and 8 weeks of age whereas TFAP2C- and POU5F1-positive cells remained unchanged. This increase in DDX4-expressing cells indicates dynamic growth of the differentiated A-spermatogonial population. The presence of cells expressing POU5F1 and TFAP2C after 8 weeks reveals the persistence of less differentiated germ cells. The mRNA and protein profiles determined by qRT-PCR and western blot in newborn, 8-week-old, and adult marmosets corroborated the immunohistochemical findings. In conclusion, we demonstrated the presence of distinct spermatogonial subpopulations in the primate testis exhibiting different dynamics during early testicular development. Our study demonstrates the suitability of the marmoset testis as a model for human testicular development.


1998 ◽  
Vol 111 (9) ◽  
pp. 1255-1265 ◽  
Author(s):  
D.J. Elliott ◽  
K. Oghene ◽  
G. Makarov ◽  
O. Makarova ◽  
T.B. Hargreave ◽  
...  

RBM is a germ-cell-specific RNA-binding protein encoded by the Y chromosome in all mammals, implying an important and evolutionarily conserved (but as yet unidentified) function during male germ cell development. In order to address this function, we have developed new antibody reagents to immunolocalise RBM in the different cell types in the human testis. We find that RBM has a different expression profile from its closest homologue hnRNPG. Despite its ubiquitous expression in all transcriptionally active germ cell types, RBM has a complex and dynamic cell biology in human germ cells. The ratio of RBM distributed between punctate nuclear structures and the remainder of the nucleoplasm is dynamically modulated over the course of germ cell development. Moreover, pre-mRNA splicing components are targeted to the same punctate nuclear regions as RBM during the early stages of germ cell development but late in meiosis this spatial association breaks down. After meiosis, pre-mRNA splicing components are differentially targeted to a specific region of the nucleus. While pre-mRNA splicing components undergo profound spatial reorganisations during spermatogenesis, neither heterogeneous ribonucleoproteins nor the transcription factor Sp1 show either developmental spatial reorganisations or any specific co-localisation with RBM. These results suggest dynamic and possibly multiple functions for RBM in germ cell development.


Reproduction ◽  
2005 ◽  
Vol 130 (6) ◽  
pp. 923-929 ◽  
Author(s):  
Rahul Rathi ◽  
Ali Honaramooz ◽  
Wenxian Zeng ◽  
Stefan Schlatt ◽  
Ina Dobrinski

Spermatogenesis can occur in testis tissue from immature bulls ectopically grafted into mouse hosts; however, efficiency of sperm production is lower than in other donor species. To elucidate a possible mechanism for the impaired spermatogenesis in bovine testis xenografts, germ cell fate and xenograft development were investigated at different time points and compared with testis tissue from age-matched calves as controls. Histologically, an initial decrease in germ cell number was noticed in xenografts recovered up to 2 months post-grafting without an increase in germ cell apoptosis. From 2 months onward, the number of germ cells increased. In contrast, a continuous increase in germ cell number was seen in control tissue. Pachytene spermatocytes were observed in some grafts before 4 months, whereas in the control tissue they were not present until 5 months of age. Beyond 4 months post-grafting spermatogenesis appeared to be arrested at the pachytene spermatocyte stage in most grafts. Elongated spermatids were observed between 6 and 8 months post-grafting, similar to the controls, albeit in much lower numbers. Lumen formation started earlier in grafts compared with controls and by 6 months post-grafting tubules with extensively dilated lumen were observed. A donor effect on efficiency of spermatogenesis was also observed. These results indicate that the low efficiency of sperm production in bovine xenografts is due to an initial deficit of germ cells and impaired meiotic and post-meiotic differentiation. The characterization of spermatogenic efficiency will provide the basis to understand the control of spermatogenesis in testis grafts.


2006 ◽  
Vol 189 (1) ◽  
pp. 137-146 ◽  
Author(s):  
A Catizone ◽  
G Ricci ◽  
J Del Bravo ◽  
M Galdieri

The hepatocyte growth factor (HGF) is a pleiotropic cytokine that influences mitogenesis, motility and differentiation of many different cell types by its tyrosine kinase receptor c-Met. We previously demonstrated that the c-Met/HGF system is present and functionally active during postnatal testis development. We found also that spermatozoa express c-Met and that HGF has a positive effect on the maintenance of sperm motility. In the present paper, we extend our study on the germ cells at different stages of differentiation during the postnatal development of the testis. We demonstrate that c-met is present in rat spermatogonia, pachytene spermatocytes and round spermatids and that HGF significantly increases spermatogonial proliferation in 8- to 10-day-old pre-pubertal rats. At this age HGF does not affect Sertoli cells and peritubular myoid cells proliferation. In addition, we studied the effect of the factor on germ cell apoptosis and we show that HGF prevents the germ cell apoptotic process. We also studied the effect of HGF on 18- to 20-day-old and 28- to 30-day-old rat testes. At these ages also the factor significantly increases germ cell duplication and decreases the number of apoptotic cells. However, the effect on programmed cell death is higher in the 8- to 10-day-old rats and declines in the older animals. In conclusion, we report that rat germ cells (spermatogonia, pachytene spermatocytes and round spermatids) express c-met and that HGF modulates germ cell proliferating activity and apoptosis in vitro. These data indicate that the c-Met/HGF system is involved in male germ cell homeostasis and, consequently, has a role in male fertility.


2013 ◽  
Vol 25 (1) ◽  
pp. 290 ◽  
Author(s):  
R. H. Powell ◽  
M. N. Biancardi ◽  
J. Galiguis ◽  
Q. Qin ◽  
C. E. Pope ◽  
...  

Spermatogonial stem cells (SSC), progenitor cells capable of both self-renewal and producing daughter cells that will differentiate into sperm, can be manipulated for transplantation to propagate genetically important males. This application was demonstrated in felids by the successful xeno-transplantation of ocelot mixed germ cells into the testes of domestic cats, which resulted in the production of ocelot sperm (Silva et al. 2012 J. Androl. 33, 264–276). Spermatogonial stem cells are in low numbers in the testis, but have been identified and isolated in different mammalian species using SSC surface markers; however, their expression varies among species. Until recently, little was known about the expression of SSC surface markers in feline species. We previously demonstrated that many mixed germ cells collected from adult cat testes express the germ cell markers GFRα1, GPR125, and C-Kit, and a smaller population of cells expresses the pluripotent SSC-specific markers SSEA-1 and SSEA-4 (Powell et al. 2011 Reprod. Fertil. Dev. 24, 221–222). In the present study, our goal was to identify germ cell and SSC-specific markers in SSC from cat testes. Immunohistochemical (IHC) localization of germ cell markers GFRα1, GPR125, and C-Kit and pluripotent SSC-specific markers SSEA-1, SSEA-4, TRA-1-60, TRA-1-81, and Oct-4 was detected in testis tissue from both sexually mature and prepubertal males. Testes were fixed with modified Davidson’s fixative for 24 h before processing, embedding, and sectioning. The EXPOSE Mouse and Rabbit Specific HRP/DAB detection IHC kit (Abcam®, Cambridge, MA, USA) was used for antibody detection. Staining for SSEA-1, SSEA-4, TRA-1-60, TRA-1-81, and Oct-4 markers was expressed specifically at the basement membrane of the seminiferous tubules in both adult and prepubertal testes. The GFRα1 and GPR125 markers were detected at the basement membrane of the seminiferous tubules and across the seminiferous tubule section. However, C-Kit was not detected in any cell. Using flow cytometry from a pool of cells from seven adult testes, we detected 45% GFRα1, 50% GPR125, 59% C-Kit, 18% TRA-1-60, 16% TRA-1-81 positive cells, and a very small portion of SSEA-1 (7%) and SSEA-4 (3%) positive cells. Dual staining of germ cells pooled from 3 testes revealed 3 distinct cell populations that were positive for GFRα1 only (23%), positive for both GFRα1 and SSEA-4 (6%), and positive for SSEA-4 only (1%). Our IHC staining of cat testes indicated that cells along the basement membrane of seminiferous tubules were positive for SSC-specific markers, and flow cytometry analysis revealed that there were different cell populations expressing both germ cell and SSC-specific markers. Flow cytometry results show overlapping germ cell populations expressing SSEA-4 and GFRα1, and IHC results reveal that SSEA-4 positive cells are spermatogonia, whereas GFRα1 positive cells include other stages of germ cells, indicating that the small population of cells positive only for SSEA-4 is undifferentiated cat SSC.


Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 415
Author(s):  
Marika Tonellato ◽  
Monica Piccione ◽  
Matteo Gasparotto ◽  
Pietro Bellet ◽  
Lucia Tibaudo ◽  
...  

Nanocomposite scaffolds combining carbon nanomaterials (CNMs) with a biocompatible matrix are able to favor the neuronal differentiation and growth of a number of cell types, because they mimic neural-tissue nanotopography and/or conductivity. We performed comparative analysis of biomimetic scaffolds with poly-L-lactic acid (PLLA) matrix and three different p-methoxyphenyl functionalized carbon nanofillers, namely, carbon nanotubes (CNTs), carbon nanohorns (CNHs), and reduced graphene oxide (RGO), dispersed at varying concentrations. qRT-PCR analysis of the modulation of neuronal markers in human circulating multipotent cells cultured on nanocomposite scaffolds showed high variability in their expression patterns depending on the scaffolds’ inhomogeneities. Local stimuli variation could result in a multi- to oligopotency shift and commitment towards multiple cell lineages, which was assessed by the qRT-PCR profiling of markers for neural, adipogenic, and myogenic cell lineages. Less conductive scaffolds, i.e., bare poly-L-lactic acid (PLLA)-, CNH-, and RGO-based nanocomposites, appeared to boost the expression of myogenic-lineage marker genes. Moreover, scaffolds are much more effective on early commitment than in subsequent differentiation. This work suggests that biomimetic PLLA carbon-nanomaterial (PLLA-CNM) scaffolds combined with multipotent autologous cells can represent a powerful tool in the regenerative medicine of multiple tissue types, opening the route to next analyses with specific and standardized scaffold features.


2004 ◽  
Vol 15 (3) ◽  
pp. 1031-1043 ◽  
Author(s):  
Ulrich Schlecht ◽  
Philippe Demougin ◽  
Reinhold Koch ◽  
Leandro Hermida ◽  
Christa Wiederkehr ◽  
...  

We report a comprehensive large-scale expression profiling analysis of mammalian male germ cells undergoing mitotic growth, meiosis, and gametogenesis by using high-density oligonucleotide microarrays and highly enriched cell populations. Among 11,955 rat loci investigated, 1268 were identified as differentially transcribed in germ cells at subsequent developmental stages compared with total testis, somatic Sertoli cells as well as brain and skeletal muscle controls. The loci were organized into four expression clusters that correspond to somatic, mitotic, meiotic, and postmeiotic cell types. This work provides information about expression patterns of ∼200 genes known to be important during male germ cell development. Approximately 40 of those are included in a group of 121 transcripts for which we report germ cell expression and lack of transcription in three somatic control cell types. Moreover, we demonstrate the testicular expression and transcriptional induction in mitotic, meiotic, and/or postmeiotic germ cells of 293 as yet uncharacterized transcripts, some of which are likely to encode factors involved in spermatogenesis and fertility. This group also contains potential germ cell-specific targets for innovative contraceptives. A graphical display of the data is conveniently accessible through the GermOnline database at http://www.germonline.org .


Reproduction ◽  
2016 ◽  
Vol 152 (5) ◽  
pp. 379-388 ◽  
Author(s):  
Jonathan T Busada ◽  
Ellen K Velte ◽  
Nicholas Serra ◽  
Kenneth Cook ◽  
Bryan A Niedenberger ◽  
...  

We previously described a novel germ cell-specific X-linkedreproductivehomeoboxgene (Rhox13) that is upregulated at the level of translation in response to retinoic acid (RA) in differentiating spermatogonia and preleptotene spermatocytes. We hypothesize that RHOX13 plays an essential role in male germ cell differentiation, and have tested this by creating aRhox13gene knockout (KO) mouse.Rhox13KO mice are born in expected Mendelian ratios, and adults have slightly reduced testis weights, yet a full complement of spermatogenic cell types. Young KO mice (at ~7–8 weeks of age) have a ≈50% reduction in epididymal sperm counts, but numbers increased to WT levels as the mice reach ~17 weeks of age. Histological analysis of testes from juvenile KO mice reveals a number of defects during the first wave of spermatogenesis. These include increased apoptosis, delayed appearance of round spermatids and disruption of the precise stage-specific association of germ cells within the seminiferous tubules. Breeding studies reveal that both young and aged KO males produce normal-sized litters. Taken together, our results indicate that RHOX13 is not essential for mouse fertility in a controlled laboratory setting, but that it is required for optimal development of differentiating germ cells and progression of the first wave of spermatogenesis.


2001 ◽  
Vol 13 (8) ◽  
pp. 609 ◽  
Author(s):  
Fang-Xu Jiang

Male germ cell transplantation is a novel technique in which donor male stem germ cells are surgically transferred to the seminiferous tubules of a recipient testis by direct injection or via the rete testis or efferent duct. All germ cells that are destined to become stem spermatogonia are defined as male stem germ cells, including primordial germ cells from the gonadal ridges, and gonocytes and stem spermatogonia from the testis, all of which are transplantable and capable of undergoing normal spermatogenesis. Xenotransplantation of male germ cells from one species into the testis of another species, including human testicular cells in the mouse, has so far proved to be unsuccessful. However, the immunodeficient mouse testis can support rat spermatogenesis and produce apparently normal rat spermatozoa. The underlying mechanisms remain elusive. The present mini-review will focus on the importance of stem spermatogonial transplantation for testicular stem cell biology and discuss the likelihood of immune rejection after transplantation, which may limit the success of all male germ cell transplantation.


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