scholarly journals Non-random distribution of spermatogonia in rats: evidence of niches in the seminiferous tubules

Reproduction ◽  
2003 ◽  
pp. 669-680 ◽  
Author(s):  
H Chiarini-Garcia ◽  
AM Raymer ◽  
LD Russell
Keyword(s):  
Basal Lamina ◽  
Random Distribution ◽  
Type A ◽  
Seminiferous Epithelium ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Primitive Type ◽  
Linear Index ◽  
Type A Spermatogonia

The relationships and distribution of spermatogonia were studied as a function of the stage of the seminiferous epithelium cycle in rats. Primitive spermatogonia in the mouse are located along regions of the basal lamina that face the interstitium. Before studying the distribution of spermatogonia in rats, it was necessary to characterize the various types of spermatogonia, as recently performed for mice. The Strauss' linear index (Li) selectivity method was then used and spermatogonia of the A(single) (A(s)) to A(aligned) (A(al)) lineage were preferentially found to be located in regions opposing the interstitium at stages V, VII and IX of the spermatogenic cycle. Because relatively little tubule-to-tubule contact occurs in rats, the aim of this study was to determine whether tubule-to-tubule contact or tubule proximity (or alternatively, the amount of interstitium) was an important factor in spermatogonial position. In this regard, another method (tubule proximity) was devised to determine spermatogonial position that accounted for the presence of adjacent tubules. This method showed that the position of tubules, rather than tubule contact, was more accurate than the Li method in determining the location of spermatogonia in the rat. The results also showed a non-random distribution of spermatogonia resembling that of the mouse, and that tubule-to-tubule contact is not essential for the positioning of spermatogonia. In conclusion, the results of this study strongly indicate that the most primitive type A spermatogonia (A(s), A(paired) and A(al)) in rats are present in niches located in those areas of the seminiferous tubules that border the interstitial tissue.

scholarly journals Propagation of bovine spermatogonial stem cells in vitro

Reproduction ◽  
2008 ◽  
Vol 136 (5) ◽  
pp. 543-557 ◽  
Author(s):  
Pedro M Aponte ◽  
Takeshi Soda ◽  
Katja J Teerds ◽  
S Canan Mizrak ◽  
Henk J G van de Kant ◽  
...  
Keyword(s):  
Stem Cells ◽  
Growth Factor ◽  
Cultured Cells ◽  
Somatic Cells ◽  
Type A ◽  
Spermatogonial Stem Cells ◽  
Seminiferous Tubules ◽  
Type A Spermatogonia ◽  
Stimulation Of

The access to sufficient numbers of spermatogonial stem cells (SSCs) is a prerequisite for the study of their regulation and further biomanipulation. A specialized medium and several growth factors were tested to study thein vitrobehavior of bovine type A spermatogonia, a cell population that includes the SSCs and can be specifically stained for the lectin Dolichos biflorus agglutinin. During short-term culture (2 weeks), colonies appeared, the morphology of which varied with the specific growth factor(s) added. Whenever the stem cell medium was used, round structures reminiscent of sectioned seminiferous tubules appeared in the core of the colonies. Remarkably, these round structures always contained type A spermatogonia. When leukemia inhibitory factor (LIF), epidermal growth factor (EGF), or fibroblast growth factor 2 (FGF2) were added, specific effects on the numbers and arrangement of somatic cells were observed. However, the number of type A spermatogonia was significantly higher in cultures to which glial cell line-derived neurotrophic factor (GDNF) was added and highest when GDNF, LIF, EGF, and FGF2 were all present. The latter suggests that a proper stimulation of the somatic cells is necessary for optimal stimulation of the germ cells in culture. Somatic cells present in the colonies included Sertoli cells, peritubular myoid cells, and a few Leydig cells. A transplantation experiment, using nude mice, showed the presence of SSCs among the cultured cells and in addition strongly suggested a more than 10 000-fold increase in the number of SSCs after 30 days of culture. These results demonstrate that bovine SSC self-renew in our specialized bovine culture system and that this system can be used for the propagation of these cells.

scholarly journals p53-Dependent Apoptosis in the Inhibition of Spermatogonial Differentiation in Juvenile Spermatogonial Depletion (Utp14bjsd) Mice

Endocrinology ◽  
2008 ◽  
Vol 149 (6) ◽  
pp. 2773-2781 ◽  
Author(s):  
Gunapala Shetty ◽  
Shan H. Shao ◽  
Connie C. Y. Weng
Keyword(s):  
Double Mutant ◽  
Fas Ligand ◽  
Type A ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Seminiferous Tubules ◽  
Caspase 9 ◽  
Apoptotic Pathway ◽  
Independent Process ◽  
Old Mice ◽  
Type A Spermatogonia

In adult male mice homozygous for the juvenile spermatogonial depletion (Utp14bjsd) mutation in the Utp14b gene, type A spermatogonia proliferate, but in the presence of testosterone and at scrotal temperatures, these spermatogonia undergo apoptosis just before differentiation. In an attempt to delineate this apoptotic pathway in jsd mice and specifically address the roles of p53- and Fas ligand (FasL) /Fas receptor-mediated apoptosis, we produced jsd mice deficient in p53, Fas, or FasL. Already at the age of 5 wk, less degeneration of spermatogenesis was observed in p53-null-jsd mice than jsd single mutants, and in 8- or 12-wk-old mice, the percentage of seminiferous tubules showing differentiated germ cells [tubule differentiation index (TDI)] was 26–29% in the p53-null-jsd mice, compared with 2–4% in jsd mutants with normal p53. The TDI in jsd mice heterozygous for p53 showed an intermediate TDI of 8–13%. The increase in the differentiated tubules in double-mutant and p53 heterozygous jsd mice was mostly attributable to intermediate and type B spermatogonia; few spermatocytes were present. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling staining showed that most of these differentiated spermatogonia still underwent apoptosis, thereby blocking further continuation of spermatogenesis. In contrast, the percentage of tubules that were differentiated was not significantly altered in either adult Fas null-jsd mice or adult FasL defective gld-jsd double mutant mice as compared with jsd single mutants. Furthermore, caspase-9, but not caspase-8 was immunochemically localized in the adult jsd mice spermatogonia undergoing apoptosis. The results show that p53, but not FasL or Fas, is involved in the apoptosis of type A spermatogonia before/during differentiation in jsd mice that involves the intrinsic pathway of apoptosis. However, apoptosis in the later stages must be a p53-independent process.

Changes in the cells of the Sex Cords and Seminiferous Tubules during the development of the Testis of the rat and mouse.

1962 ◽  
Vol 10 (2) ◽  
pp. 178 ◽  
Author(s):  
CS Sapsford
Keyword(s):  
Basement Membrane ◽  
Type A ◽  
Staining Intensity ◽  
Seminiferous Tubules ◽  
Postnatal Life ◽  
Foetal Development ◽  
Cytoplasmic Inclusions ◽  
Daughter Cells ◽  
Early Postnatal Life ◽  
Type A Spermatogonia

The sex cords of the testis of the foetal rat and mouse are made up of two types of cell- the gonocytes and the indifferent cells. During foetal and early postnatal life, the former undergo a process of maturation involving principally an increase in size and in number of cytoplasmic inclusions. Nuclear enlargement is accompanied by a diminution in staining intensity. Gonocytes are more centrally placed within the sex cords than indifferent cells, and in the later stages of foetal development they cease to divide. In the first week of postnatal life, however, they resume mitotic activity and migrate to the basement membrane of the sex cords. Gonocytes as such disappear and are replaced by smaller daughter cells, the immature type A spermatogonia. The appearance of the latter is followed by the onset of spermatogenesis. As the tubules gradually become filled with the layers of cells of the spermatogenic line, the daughter cells of the gonocytes become flattened against the basement membrane, and come to resemble the type A spermatogonia found in the adult. Indifferent cells, which are always cytologically distinct from gonocytes and spermatogonia, exist as mononucleate units. The pattern of change of these cells during the development of the testis is different from that of the germ cells. Unlike the gonocytes, the indifferent cells continue to divide during foetal and early postnatal life. Little change takes place in these cells until after the onset of spermatogenesis, when they gradually increase in size and become Sertoli cells. The latter are principally mononucleate in form.

The behaviour of mitotic nuclei after transplantation to early meiotic ooplasts or mitotic cytoplasts

Zygote ◽  
1997 ◽  
Vol 5 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Michal Kubelka ◽  
Robert M. Moor
Keyword(s):  
High Activity ◽  
Somatic Cells ◽  
Type A ◽  
Chromosome Condensation ◽  
Premature Chromosome Condensation ◽  
Primitive Type ◽  
Dividing Cells ◽  
Pronuclear Formation ◽  
Further Development ◽  
Type A Spermatogonia

SummaryThis study evaluates the ability of the cytoplasm to determine the nature of the division cycle (meiotic or mitotic) in nuclei obtained from mitotically dividing cells. Using mouse oocytes in different stages of development two types of cytoplasm were prepared: firstly, early meiotic ooplasts were obtained by enucleation of non-matured, prophase-stage oocytes; secondly, mitotic cytoplasts were prepared by enucleation and activation of metaphase II (Mll)-stage oocytes. These two types of cytoplasts were then used in fusion experiments, in which mouse primitive type A spermatogonia (prospermatogonia) or mouse fibroblasts were used as a source of donor nuclei. While the fusion of prospermatogonia with mitotic cytoplasts resulted, as expected, in normal premature chromosome condensation (PCC) and subsequent pronuclear formation (58.1%), the majority of hybrids obtained by fusion of prospermatogonia with early meiotic ooplasts (40.3%) displayed unique morphology consisting of two sets of chromosomes organised in two spindle centres connected by microtubules. Each set of chromosomes contained the haploid (1n) number of chromosomes as revealed by chromosome analyses. The same morphology was observed also in 44.2% of hybrids in which the differentiated nuclei of fibroblasts were used as a source of donor mitotic nuclei. In both cases the hybrids were blocked at this stage with high activity of maturation promoting factor (MPF), resistant to any kind of activation and not able to undergo further development. These results suggest that the early meiotic ooplasm was able to induce the initiation of a meiosis-like reducing division in mitotic nuclei originating both from the germline cells and from more differentiated somatic cells.

Correlation between blood-testis barrier development and onset of the first spermatogenic wave in normal and busulfan-treated rats

1990 ◽  
Vol 48 (3) ◽  
pp. 78-79
Author(s):  
Juan C. Cavicchia ◽  
Fabio L. Sacerdote
Keyword(s):  
Germ Cell ◽  
Tight Junctions ◽  
Basal Lamina ◽  
Sertoli Cells ◽  
Freeze Fracture ◽  
Seminiferous Epithelium ◽  
Seminiferous Tubules ◽  
Pregnant Rats ◽  
Synaptonemal Complexes ◽  
New Born

Pregnant rats (day 13) received 10mg/kg of Busulfan i.p. in order to deplete of germ cell the testes of the new born rats. The seminiferous tubules of their off spring from postnatal age 1 day up to day 35 were examined with TEM after fixation plus intercellular tracers, and with freeze-fracture techniques. During this period, the inter-Sertoli tight junctions of controls increase both in numbers and in length. Between days 10 and 13 the seminiferous cords have numerous preleptotene and leptotene spermatocytes (Fig.1) surrounded by tracer. The inter-Sertoli junctions are tortuous and predominantly perpendicular to the basal lamina. Between ages 13 and 20 days the seminiferous epithelium reaches zygotene-pachytene stages (fig.2) identified by the presence of synaptonemal complexes. The tracer is stopped at the inter-Sertoli junctions at this stage, whereas it still permeates tubules displaying preleptotene and leptotene spermatocytes.Freeze-fracture shows that the orientation of inter-Sertoli junctions has changed to parallel, both to each other and to the basal lamina (fig.3). In the Busulfan treated rats, the tubules continue having, up to postnatal day 30, only Sertoli cells and scanty spermatogonia.

scholarly journals Spermatogenic cells of the prepuberal mouse: isolation and morphological characterization

1977 ◽  
Vol 74 (1) ◽  
pp. 68-85 ◽  
Author(s):  
AR Bellve ◽  
JC Cavicchia ◽  
CF Millette ◽  
DA O'Brien ◽  
YM Bhatnagar ◽  
...  
Keyword(s):  
Sertoli Cells ◽  
Morphological Characteristics ◽  
Type A ◽  
Cell Types ◽  
Specific Cell ◽  
Spermatogenic Cells ◽  
Type B ◽  
Primitive Type ◽  
Pachytene Spermatocytes ◽  
Type A Spermatogonia

A procedure is described which permits the isolation from the prepuberal mouse testis of highly purified populations of primitive type A spermatogonia, type A spermatogonia, type B spermatogonia, preleptotene primary spermatocytes, leptotene and zygotene primary spermatocytes, pachytene primary spermatocytes and Sertoli cells. The successful isolation of these prepuberal cell types was accomplished by: (a) defining distinctive morphological characteristics of the cells, (b) determining the temporal appearance of spermatogenic cells during prepuberal development, (c) isolating purified seminiferous cords, after dissociation of the testis with collagenase, (d) separating the trypsin-dispersed seminiferous cells by sedimentation velocity at unit gravity, and (e) assessing the identity and purity of the isolated cell types by microscopy. The seminiferous epithelium from day 6 animals contains only primitive type A spermatogonia and Sertoli cells. Type A and type B spermatogonia are present by day 8. At day 10, meiotic prophase is initiated, with the germ cells reaching the early and late pachytene stages by 14 and 18, respectively. Secondary spermatocytes and haploid spermatids appear throughout this developmental period. The purity and optimum day for the recovery of specific cell types are as follows: day 6, Sertoli cells (purity>99 percent) and primitive type A spermatogonia (90 percent); day 8, type A spermatogonia (91 percent) and type B spermatogonia (76 percent); day 18, preleptotene spermatocytes (93 percent), leptotene/zygotene spermatocytes (52 percent), and pachytene spermatocytes (89 percent), leptotene/zygotene spermatocytes (52 percent), and pachytene spermatocytes (89 percent).

scholarly journals PSXIII-1 Age-related changes in the ratio of different spermatogonia types in the seminiferous tubules of quail testes

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 373-374
Author(s):  
Evgeniya K Tomgorova ◽  
Natalia A Volkova ◽  
Anastasia N Vetokh ◽  
Inna P Novgorodova ◽  
Ludmila A Volkova ◽  
...  
Keyword(s):  
Early Period ◽  
Type A ◽  
Seminiferous Tubules ◽  
Maximum Value ◽  
Age Related ◽  
Spermatogonia Cells ◽  
Hematoxylin Eosin ◽  
Generative Cells ◽  
Testis Tissue ◽  
Type A Spermatogonia

Abstract Spermatogonia are early-undifferentiated germ cells, giving rise to mature male generative cells — the spermatozoa. There are two types of spermatogonia – A and B. Of greatest interest is the use of type A spermatogonia, which are the stem cells of the testes. To select the appropriate age for collecting spermatogonia А from quails it is necessary to know the specific features of spermatogenesis. Development dynamics of various spermatogonia types in the quail testicular tubules was studied. Histological studies of the quails testicular tubules at the age of 1, 2, 3, 4, 5 and 6 weeks (n = 30) were carried out. Samples of testis tissue were fixed in Bouin’s fixative. Histological sections were stained with hematoxylin-eosin. Identification of different spermatogonia types was carried out according to their morphology. Type A spermatogonia were additionally identified by immunohistochemistry using SSEA-1 antibodies. The proportion of spermatogonia in the total number of spermatogenic cells in the seminiferous tubules of quails changed with age. The maximum value was reached at the age of 3 weeks and it was 76±6%. On reaching maturity (6 weeks), this indicator decreased to 12 ± 1 %. In the early period of ontogenesis (1–2 weeks), spermatogonia cells were represented mainly by type A spermatogonia. The proportion of these cells from the total number of spermatogonia reached 80 ± 3 %. With increasing age, this indicator decreased, reaching minimum values for achieving maturity (6 weeks) - 16 ± 1 %. The percentage of type B spermatogonia in the seminiferous tubule of quails on the contrary increased with age — from 5 ± 1% at 1 week old to 70 ± 2% at maturity. Thus, the age no later than 2 weeks is the most optimal for the isolation type A spermatogonia of quails. Supported by RFBR (18-29-07079).

scholarly journals 11β-Hydroxylase loss disrupts steroidogenesis and reproductive function in zebrafish

2020 ◽  
Vol 247 (2) ◽  
pp. 197-212
Author(s):  
James A Oakes ◽  
Lise Barnard ◽  
Karl-Heinz Storbeck ◽  
Vincent T Cunliffe ◽  
Nils P Krone
Keyword(s):  
Reproductive Function ◽  
Type A ◽  
Seminiferous Tubules ◽  
Sex Characteristics ◽  
Secondary Sexual Characteristics ◽  
Secondary Sex Characteristics ◽  
Sexual Characteristics ◽  
Predominantly Female ◽  
And Function ◽  
Type A Spermatogonia

The roles of androgens in male reproductive development and function in zebrafish are poorly understood. To investigate this topic, we employed CRISPR/Cas9 to generate cyp11c1 (11β-hydroxylase) mutant zebrafish lines. Our study confirms recently published findings from a different cyp11c1−/− mutant zebrafish line, and also reports novel aspects of the phenotype caused by loss of Cyp11c1 function. We report that Cyp11c1-deficient zebrafish display predominantly female secondary sex characteristics, but may possess either ovaries or testes. Moreover, we observed that cyp11c1−/− mutant male zebrafish are profoundly androgen- and cortisol-deficient. These results provide further evidence that androgens are dispensable for testis formation in zebrafish, as has been demonstrated previously in androgen-deficient and androgen-resistant zebrafish. Herein, we show that the testes of cyp11c1−/− mutant zebrafish exhibit a disorganised tubular structure; and for the first time demonstrate that the spermatic ducts, which connect the testes to the urogenital orifice, are severely hypoplastic in androgen-deficient zebrafish. Furthermore, we show that spermatogenesis and characteristic breeding behaviours are impaired in cyp11c1−/− mutant zebrafish. Expression of nanos2, a type A spermatogonia marker, was significantly increased in the testes of Cyp11c1-deficient zebrafish, whereas expression of markers for later stages of spermatogenesis was significantly decreased. These observations indicate that in zebrafish, production of type A spermatogonia is androgen-independent, but differentiation of type A spermatogonia is an androgen-dependent process. Overall, our results demonstrate that whilst androgens are not required for testis formation, they play important roles in determining secondary sexual characteristics, proper organisation of seminiferous tubules, and differentiation of male germ cells.

Dislocated type-A spermatogonia in human seminiferous tubules

1984 ◽  
Vol 236 (1) ◽  
pp. 35-40 ◽  
Author(s):  
A.F. Holstein ◽  
E. Bustos-Obreg�n ◽  
M. Hartmann
Keyword(s):  
Type A ◽  
Seminiferous Tubules ◽  
Type A Spermatogonia

scholarly journals Three-dimensional genome reorganization during mouse spermatogenesis

2019 ◽  
Author(s):  
Zhengyu Luo ◽  
Xiaorong Wang ◽  
Ruoyu Wang ◽  
Jian Chen ◽  
Yusheng Chen ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Type A ◽  
Pachytene Stage ◽  
Open Chromatin ◽  
Biological Processes ◽  
Primitive Type ◽  
Chromatin Loops ◽  
Genome Reorganization ◽  
Type A Spermatogonia

AbstractThree-dimensional genome organization plays an important role in many biological processes. Yet, how the genome is packaged at the molecular level during mammalian spermatogenesis remains unclear. Here, we performed Hi-C in seven sequential stages during mouse spermatogenesis. We found that topological associating domains (TADs) and chromatin loops underwent highly dynamic reorganization. They displayed clear existence in primitive type A spermatogonia, disappearance at pachytene stage, and reestablishment in spermatozoa. Surprisingly, even in the absence of TADs and chromatin loops at pachytene stage, CTCF remained bound at TAD boundary regions (identified in primitive type A spermatogonia). Additionally, many enhancers and promoters exhibited features of open chromatin and transcription remained active at pachytene stage. A/B compartmentalization and segmentation ratio were conserved in different stages of spermatogenesis in autosomes, although there were A/B compartment switching events correlated with gene activity changes. Intriguingly, A/B compartment structure on the X chromosome disappeared during pacSC, rST and eST stages. Together, our work uncovered a dynamic three-dimensional chromatin organization during mouse spermatogenesis and suggested that transcriptional regulation could be independent of TADs and chromatin loops at specific developmental stages.

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