scholarly journals Duplicated insertion mutation in the microtubule-associated protein Spag5 (astrin/MAP126) and defective proliferation of immature Sertoli cells in rat hypogonadic (hgn/hgn) testes

Reproduction ◽  
2006 ◽  
Vol 132 (1) ◽  
pp. 79-93 ◽  
Author(s):  
Hiroetsu Suzuki ◽  
Mio Yagi ◽  
Katsushi Suzuki

Male rats with hypogonadism (hgn/hgn) experience sterility from testicular dysplasia, which is controlled by a single recessive gene, hgn. The postnatal growth of the seminiferous tubules was severely affected. In this study, we localized thehgnlocus to a 320 kb region on rat chromosome 10 and detected the insertion of a 25 bp duplication into the sixth exon of the sperm-associated antigen 5 (Spag5/astrin/MAP126) gene, which codes for a microtubule-associated protein. This mutation results in a truncatedSpag5protein lacking the primary spindle-targeting domain at the C terminus. Immunological staining with antibodies to markers for Sertoli and germ cells during the early postnatal period indicated that the abnormal mitosis with dispersed chromosomes inhgn/hgntestes occurs in proliferating Sertoli cells. Therefore, apoptotic Sertoli cell death would result from the disorganization of the spindle apparatus caused by defectiveSpag5. These findings suggested that theSpag5is essential for testis development in rats and that thehgn/hgnrat is a unique animal model for studying the function ofSpag5.

2016 ◽  
Vol 28 (2) ◽  
pp. 164
Author(s):  
F. Oliveira ◽  
A. Santos ◽  
A. A. Neto

Sexual differentiation in mammals is an event that presents many variations between species. Because it is related to hormonal function, any imbalance in the androgens and estrogens production can lead to malformations. Because sexual differentiation occurs in different ways among various animals, the recognition of their peculiarities becomes important in order to correct reproductive handling in different species. Considering that the guinea pig is commonly used as an experimental model in the reproductive area, the goal of this work was to perform a morphological description of gonad differentiation of the male guinea pig during embryonic development. In total, 11 conceptuses with ages 25 (n = 3), 30 (n = 2), 40 (n = 2), 50 (n = 2), and 65 (n = 2) days were used for light microscopy processing. The embryos at 25 days were processed completely. For the others, the gonads were dissected. The samples were dehydrated in alcohol, embedded in paraffin, and 5-µm sections were stained with hematoxylin-eosin. In the guinea pig gonad at 25 days gestation, there was a presence of gonadal cords, formed by condensation of somatic cells, which is characteristic of an undifferentiated gonad. In addition, we observed the presence of mesonephric and paramesonephric ducts in different embryos, indicating that other genital system organs were not formed. For the 30 days of development of guinea pigs, we observed that gonadal cords were differentiated in testicular cords by invasion of mesenchymal and endothelial cells, and also composed of Sertoli cells and primordial germ cells. These cords were among a large amount of testicular mesenchyme at the 40-day group. With 50- and 65-day development samples, the gonad was completely differentiated into testicle, with the presence of spermatogonia and Sertoli cells in the seminiferous tubules, and a large amount of interstitial Leydig cells around the tubules. We conclude that gonadal differentiation in guinea pig males occurs around the middle of pregnancy, between 25 and 30 days and that, before the end of the pregnancy, at 50 days, the testicle presents morphology similar to that found in the postnatal period.


2005 ◽  
Vol 17 (2) ◽  
pp. 308 ◽  
Author(s):  
Y. Iwanami ◽  
T. Kobayashi ◽  
M. Kato ◽  
M. Hirabayashi ◽  
S. Hochi

Mammalian spermatogenesis is a complex process of germ cell development at the seminiferous tubules whereby diploid spermatogonia proliferate and differentiate into haploid spermatozoa via round and elongating spermatids in close association with somatic Sertoli cells. In the present study, the potential of rat spermatogonia to undergo meiosis during co-culture with Sertoli cells was assessed. The type-A spermatogonia and Sertoli cells were prepared from Day 7 heterozygous transgenic male rats carrying EGFP DNA, and co-cultured on the dishes (coated; BD Falcon™ 35-3801, or non-coated: BD Falcon™ 35-1008, 4 × 106 cells/4-mL dish) at 37°C for 3 days and at 34°C for a subsequent 7 days in 5% CO2 in air. The culture medium was DMEM medium supplemented with 10% fetal bovine serum, growth factors (10 ng/mL EGF and 10 ng/mL IGF) and various hormones (500 ng/mL FSH, 133 μIU/mL hGH, 5 μg/mL insulin, 0.1 μM testosterone and 0.1 μM dihydrotestosterone). During culture, appearance of round spermatid-like cells (ca. 15 μm in cellular diameter and 7–8 μm in nuclear diameter) was traced. The ploidy of the cells was also analyzed by flow cytometry (FCM). At the end of culture, the proportion of EGFP DNA-bearing cells in the total cultured cell population was examined under UV light at 365 nm. Thereafter, continuation of the spermatid-like cells to full-term development was examined by ooplasmic microinjection (Kato et al. 2004 Contemp. Top. Lab. Anim. Sci. 43/2, 13). Briefly, oocytes from the Sprague-Dawley rats were denuded, activated with two direct-current pulses at 100 V/mm for 99 μs and held in 2 mM 6-dimethylaminopurine for 20 min. The nuclei of spermatid-like cells were microinjected into the oocytes by using a piezo impact driving unit, and the injected oocytes after 24 h culture were transferred into recipients. Round spermatid-like cells were first observed at the 5th day of culture on both dishes, but the proportion of spermatid-like cells on the coated dish was higher than that on the non-coated dish. The FCM analysis showed that a single peak of haploid cells was detected in the cell population cultured on the coated dish at the 5th day of culture, while no haploid peak was detected on the non-coated dish. The cultured cells exhibited two distinct patterns of EGFP fluorescence, with a proportion of EGFP-positive cells at 53.5% (total 1,000 counts). The microinsemination into 263 oocytes resulted in the production of 27 oocytes with two pronuclei (10.3%) and 15 cleaved oocytes (5.7%). However, the oviductal transfer of 143 microinseminated oocytes resulted in only 8 implantation sites without viable offspring (5.6%). These results indicated that rat type-A spermatogonial cells seemed to undergo meiosis, but the potential of the cultured spermatid-like cells to participate into full-term development was questionable.


2005 ◽  
Vol 73 (5) ◽  
pp. 2611-2620 ◽  
Author(s):  
Yongming Sang ◽  
M. Teresa Ortega ◽  
Frank Blecha ◽  
Om Prakash ◽  
Tonatiuh Melgarejo

ABSTRACT Mammalian β-defensins are small cationic peptides possessing broad antimicrobial and physiological activities. Because dogs are particularly resilient to sexually transmitted diseases, it has been proposed that their antimicrobial peptide repertoire might provide insight into novel antimicrobial therapeutics and treatment regimens. To investigate this proposal, we cloned the full-length cDNA of three canine β-defensin isoforms (cBD-1, -2, and -3) from canine testicular tissues. Their predicted peptides share identical N-terminal 65-amino-acid residues, including the β-defensin consensus six-cysteine motif. The two longer isoforms, cBD-2 and -3, possess 4 and 34 additional amino acids, respectively, at the C terminus. To evaluate the antimicrobial activity of cBD, a 34-amino-acid peptide derived from the shared mature peptide region was synthesized. Canine β-defensin displayed broad antimicrobial activity against gram-positive bacteria (Listeria monocytogenes and Staphylococcus aureus; MICs of 6 and 100 μg/ml, respectively), gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, and Neisseria gonorrhoeae; MICs of 20 to 50, 20, and 50 μg/ml, respectively), and yeast (Candida albicans; MIC of 5 to 50 μg/ml) and lower activity against Ureaplasma urealyticum and U. canigenitalium (MIC of 200 μg/ml). Antimicrobial potency was significantly reduced at salt concentrations higher than 140 mM. All three canine β-defensins were highly expressed in testis. In situ hybridization indicated that cBD-1 was expressed primarily in Sertoli cells within the seminiferous tubules. In contrast, cBD-2 was located primarily within Leydig cells. The longest isoform, cBD-3, was detected in Sertoli cells and to a lesser extent in the interstitium. The tissue-specific expression and broad antimicrobial activity suggest that canine β-defensins play an important role in host defense and other physiological functions of the male reproductive system.


2018 ◽  
Vol 9 (4) ◽  
pp. 373-376 ◽  
Author(s):  
G. G. Ribeiro ◽  
L. R. Pessôa ◽  
M. D. C. de Abreu ◽  
L. B. N. S. Corrêa ◽  
A. D’Avila Pereira ◽  
...  

AbstractThis study evaluated the effects of diet containing taro flour on hormone levels and the seminiferous tubules morphology of rats. After weaning, the male rats were divided into two groups (n=12 each): control group (CG) treated with control diet and taro group (TG), fed with 25% taro flour for 90 days. Food, caloric intake, mass and body length were evaluated at experiment end. Testis followed the standard histological processing. Immunostaining was performed using an anti-vimentin antibody to identify Sertoli cells. In histomorphometry, total diameter, total area, epithelial height, luminal height and luminal area were analyzed. The testosterone levels were performed using the radioimmunoassay method. Group TG presented (P<0.05): increase in mass, body length, testicular weight, histomorphometric parameters and hormonal levels. Food intake, calorie and Sertoli cells not presented statistical differences. The taro promoted increase in the testicles parameters and hormones.


2019 ◽  
Vol 18 (4) ◽  
pp. 24-28
Author(s):  
M. S. Hnatjuk ◽  
S. O. Konovalenko ◽  
L. V. Tatarchuk

The testes of 50 white male rats were divided into 3 groups studied morphologically. Group 1 consisted of 15 intact animals, 2 – 25 rats with postresection portal hypertension, 3 – 10 animals with postresection portal hypertension and multiple organ failure. Euthanasia of rats was performed by bloodletting under thiopental anesthesia a month after the beginning of the experiment. Micropreparations from the testes were stained with hematoxylin-eosin, toluidine blue, using the Weigert method, van Gieson, Mallory. Morphometrically, on the testicular micropreparations, the diameters of the testicles tubules, the thickness of their walls, the number of cells of the epithelial-spermatogenic layer in the tubule, the number of Sertoli cells per tubule, the tubulo-interstitial index, the stromal-parenchymal ratio, the Leydigas index, the sperm index, were determined. Quantitative morphological parameters were processed statistically. The investigated morphometric indices of the testes in the 2 and 3 groups of observations were found to vary markedly in comparison with the control values. Thus, the diameter of the seminiferous tubules in the conditions of postresection portal hypertension was statistically significantly (p˂0.001) decreased by 11.8 %, with the development of multiple organ failure – by 34.0 % (p<0.001), and the number of cells of the epithelialspermatogenic layer in tubules respectively by 11.3 % and 32.9 % (p˂0.001), which indicated the presence of atrophy of the studied structures. The wall thickness of the tubules in the 2 group increased by 8.8%, in the 3 group – by 26.9 % (р<0.001), and the Leydig index – by 22.9 % and 57.8 %, respectively (р<0.001). The number of Sertoli cells in one testicle tubule in the 2nd group decreased by 1.6 % and in the 3rd by 8.06 % (p<0.001). Stromal-parenchymal ratios in the testes with simulated pathology statistically significantly increased (р<0.001) by 11.3 % (р˂0.01) and 31.8 % (р˂0.001), while the tubular-interstitial index decreased respectively by 8.9 % (p<0.001) and 31.8 % (p<0.001). The revealed changes of the investigated morphometric parameters showed a pronounced increase in the number of stroma in the testes. The spermatogenesis intensity index also decreased by 2.9 % (p<0.05) and 38.8 % (p<0.001), respectively. Obtained morphometric parameters indicate that the simulated pathology leads to a decrease in the diameter of the tubules and the thickening of their walls. In the latter, optically sclerosis was observed. In the lumen of the seminiferous tubules, histologic examination found spermatocytes of the first order and spermatogonia, rarely observed spermatocytes of the second order. Protein detritus and rarely sperm were detected in the tubules. Thus, postresection portal hypertension and multiple organ failure lead to pronounced structural rebuilding of the vascular, interstitial and endocrine components of the testes, characterized by dilatation, plethora, varicose extensions, stasis, hemorrhage, perivasal swelling of the vessels of the gemomicrocirculatory bad and, hyperplasia, moderate hypertrophy, and Leydig cell dystrophy. The detected morphological changes dominate in case of multiple organ failure.


2021 ◽  
Vol 21 (4) ◽  
pp. 76-88
Author(s):  
O. L. Kolomiets ◽  
E. E. Bragina ◽  
A. A. Kashintsova ◽  
V. E. Spangenberg ◽  
L. A. Nikulina ◽  
...  

Introduction. Metabolic syndrome (MS) can cause impaired spermatogenesis and a decrease in sperm counts. However, the details of the effect of MS on developing spermatogenic cells remain unclear. Difficulties in solving this problem, the inconsistency of published clinical data, indicate the advisability of using experimental models to solve this urgent problem of andrology and reproductology.The study objective is to describe to investigate the specifics of the course of meiotic prophase I and the activity of the processes of phagocytosis and autophagy in Sertoli cells of rats with experimentally induced MS and in the course of therapeutic and prophylactic procedures during the development of experimental MS.Materials and methods. The animals were divided into three groups, each of which included four sexually mature male rats: 1st group – males fed a standard diet; 2nd group – males receiving a diet high in fat and fructose for 60 days; 3rd group – males with MS receiving sulphate mineral waters therapy, low-intensity ultrahigh frequency electromagnetic radiation therapy. Testicular cells were examined using light and transmission electron microscopy. For the first time in animals with MS, an immunocytochemical study of the peculiarities of chromosome synapsis in prophase I of meiosis was carried out on the basis of analysis of spread synaptonemal complexes of meiotic chromosomes and immunocytochemical analysis of Sertoli cells and spermatogenic cells in squashed preparations of seminiferous tubules. The parametric Student’s t-test and the nonparametric Mann–Whitney U-test were used for statistical data processing.Results. As a result of a histological study of the structure of the seminiferous tubules of animals of three groups, a statistically significant decrease in the indices of the spermatogenesis index in 2nd and 3rd groups compared to the control was revealed. Immunomorphologically, in the spread nuclei of primary spermatocytes of rats of the 2nd and 3rd groups, violations of the architectonics of nuclei, the formation of synaptonemal complexes fragments and circular synaptonemal complexes, numerous atypical inclusions were found. Signs of pachytene arrest were found in 40–50 % of spermatocyte nuclei. In the study of squashed cells preparations of the seminiferous tubules of rats of the 2nd and 3rd groups, signs of phagocytosed synaptonemal complexes were found in the cytoplasm of Sertoli cells, which were confirmed using antibodies to the SCP3 protein. Thus, evidence for the phagocytosis of degenerating primary spermatocytes by Sertoli cells has been obtained. In Sertoli cells, spermatocytes and spermatids, many autophagosomes are found, using LC3B protein marker. The presence of autophagosomes in Sertoli cells and spermatogenic cells in animals of these two groups was also confirmed by electron microscopy. In male rats of the 2nd group, significant disturbances in the structure of the pachytene nuclei were revealed. In the cytoplasm of Sertoli cells and spermatids of rats of the 2nd group, lipid droplets, numerous phagolysosomes containing cell detritus were revealed. Structural damage and phagocytosis of mitochondria were found in Sertoli cells and spermatocytes. Аutophagy in Sertoli cells were most distinctive in animals of the 3rd group.Conclusion. In male rats with experimental MS, significant disturbances in the structure of the nuclei of meiotic cells, a high content of primary spermatocytes with signs of pachytene arrest were revealed. The results obtained are in good agreement with the data of other authors, who revealed a decrease in the number of spermatozoa in the epididymis of rats and mice when modeling MS. It is assumed that the activation of autophagy is an important factor in supporting the viability of Sertoli cells and supporting the viability of germ cells in stressful situations, including MS. Apparently, autophagy is an adaptive mechanism that removes the remnants of apoptotic spermatogenic cells that are selected as a result of MS development.


1999 ◽  
Vol 112 (9) ◽  
pp. 1337-1344
Author(s):  
A. Meinhardt ◽  
M. Bacher ◽  
M.K. O'Bryan ◽  
J.R. McFarlane ◽  
C. Mallidis ◽  
...  

Macrophage migration inhibitory factor (MIF), one of the first cytokines to be discovered, has recently been localized to the Leydig cells in adult rat testes. In the following study, the response of MIF to Leydig cell ablation by the Leydig cell-specific toxin ethane dimethane sulfonate (EDS) was examined in adult male rats. Testicular MIF mRNA and protein in testicular interstitial fluid measured by ELISA and western blot were only marginally reduced by EDS treatment, in spite of the fact that the Leydig cells were completely destroyed within 7 days. Immunohistochemistry using an affinity-purified anti-mouse MIF antibody localized MIF exclusively to the Leydig cells in control testes. At 7 days post-EDS treatment, there were no MIF immunopositive Leydig cells in the interstitium, although distinct MIF immunostaining was observed in the seminiferous tubules, principally in Sertoli cells and residual cytoplasm, and some spermatogonia. A few peritubular and perivascular cells were also labelled at this time, which possibly represented mesenchymal Leydig cell precursors. At 14 and 21 days, Sertoli cell MIF immunoreactivity was observed in only a few tubule cross-sections, while some peritubular and perivascular mesenchymal cells and the re-populating immature Leydig cells were intensely labeled. At 28 days after EDS-treatment, the MIF immunostaining pattern was identical to that of untreated and control testes. The switch in the compartmentalization of MIF protein at 7 days after EDS-treatment was confirmed by western blot analysis of interstitial tissue and seminiferous tubules separated by mechanical dissection. These data establish that Leydig cell-depleted testes continue to produce MIF, and suggest the existence of a mechanism of compensatory cytokine production involving the Sertoli cells. This represents the first demonstration of a hitherto unsuspected pattern of cellular interaction between the Leydig cells and the seminiferous tubules which is consistent with an essential role for MIF in male testicular function.


1995 ◽  
Vol 14 (11) ◽  
pp. 889-894 ◽  
Author(s):  
N. Pant ◽  
AK Prasad ◽  
SC Srivastava ◽  
R. Shankar ◽  
SP Srivastava

1 Carbofuran was administered orally to adult male rats at dose levels of 0.1, 0.2, 0.4 or 0.8 mg kg -1 body weight, 5 d wk-1 for 60 days. A dose dependent decrease was observed in body weight of rats treated with 0.2-0.8 mg carbofuran kg -1 body weight 2 A significant decrease in the weight of epididymides, seminal vesicles, ventral prostate and coagulating glands was observed at various test doses of carbofuran except at the lowest dose. 3 Decreased sperm motility, reduced epididymal sperm count along with increased morphological abnormali ties in head, neck and tail regions of spermatozoa were observed in rats exposed to 0.2, 0.4, or 0.8 mg carbo furan kg-1 body weight. 4 In addition, significant alterations were observed in the activities of marker testicular enzymes viz. sorbitol dehydrogenase (SDH), glucose-6-P-dehydrogenase (G6PDH) (decreased), lactate dehydrogenase (LDH) and γ-glutamyl transpeptidase (γ-GT) (increased) depending on dose. 5 Histologically, the results indicated the toxicity of carbo furan on testes depending on dose. The changes pre dominantly consisted of moderate oedema, congestion, damage to Sertoli cells and germ cells, along with the accumulation of cellular debris and presence of giant cells in the lumen of a few seminiferous tubules which showed disturbed spermatogenesis with the higher doses of carbofuran. 6 These observations determined a no effect level dose of 0.1 mg kg-1 body weight of carbofuran on the biochemi cal and morphological indices studied for male repro ductive toxicity assessment in the rat model. The results of the present study provide first hand information on the reproductive toxicity of carbofuran in male rats.


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