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11 pages, 2112 KiB

Open AccessArticle

The Modulation of Functional Status of Bovine Spermatozoa by Progesterone

by Vitaly Denisenko, Irena Chistyakova, Natalia Volkova, Ludmila Volkova, Baylar Iolchiev and Tatyana Kuzmina

Animals 2021, 11(6), 1788; https://doi.org/10.3390/ani11061788 - 15 Jun 2021

Cited by 2 | Viewed by 2846

Abstract

The aim of this study is to identify the effects of progesterone (PRG) on the capacitation and the acrosome reaction in bovine spermatozoa. The fresh sperm samples were incubated with and without capacitation inductors (heparin, dibutyryl cyclic adenosine monophosphate (dbcAMP)), hormones (prolactin (PRL), [...] Read more.

The aim of this study is to identify the effects of progesterone (PRG) on the capacitation and the acrosome reaction in bovine spermatozoa. The fresh sperm samples were incubated with and without capacitation inductors (heparin, dibutyryl cyclic adenosine monophosphate (dbcAMP)), hormones (prolactin (PRL), PRG), inhibitors of microfilaments (cytochalasin D) and microtubules (nocodazole) during capacitation and acrosome reactions. The functional status of spermatozoa was examined using the chlortetracycline assay. Supplementation of heparin stimulated capacitation in the presence and absence of PRG. Cytochalasin D blocked the stimulating effect of heparin on capacitation. The addition of PRL during capacitation (without PRG) did not affect the functional status of spermatozoa, while in PRG-treated cells PRL stimulated the acrosome reaction. PRL (with and without PRG) increased the acrosome reaction in capacitated cells. These PRL-dependent effects were inhibited by nocodazole. During the acrosome reaction, in presence of dbcAMP, PRG decreased the proportion of acrosome-reacted cells compared to PRG-untreated cells. This effect in PRG-treated cells was canceled in the presence of nocodazole. In conclusion, PRG under the action of PRL and dbcAMP determines the changes in the functional status of native sperm cells, which indicates PRG modulating effect on the indicators of post-ejaculatory maturation of spermatozoa. Full article

(This article belongs to the Special Issue New Insights into Animal Spermatogenesis)

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15 pages, 1290 KiB

Open AccessArticle

Proliferative and Apoptotic Pathways in the Testis of Quail Coturnix coturnix during the Seasonal Reproductive Cycle

by Sara Falvo, Luigi Rosati, Maria Maddalena Di Fiore, Federica Di Giacomo Russo, Gabriella Chieffi Baccari and Alessandra Santillo

Animals 2021, 11(6), 1729; https://doi.org/10.3390/ani11061729 - 09 Jun 2021

Cited by 7 | Viewed by 3230

Abstract

The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17β-estradiol (E₂) and androgens are [...] Read more.

The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17β-estradiol (E₂) and androgens are higher during the reproductive period compared to the non-reproductive period, which led us to hypothesize that estrogens and androgens may act synergistically to initiate spermatogenesis. The present study was, therefore, aimed to investigate the estrogen responsive system in quail testis in relation to the reproduction seasonality, with a focus on the molecular pathways elicited in both active and regressive quail testes. Western blotting and immunohistochemistry analysis revealed that the expression of ERα, which is the predominant form of estrogen receptors in quail testis, was correlated with E₂ concentration, suggesting that increased levels of E₂-induced ERα could play a key role in the resumption of spermatogenesis during the reproductive period, when both PCNA and SYCP3, the mitotic and meiotic markers, respectively, were also increased. In the reproductive period we also found the activation of the ERK1/2 and Akt-1 kinase pathways and an increase in second messengers cAMP and cGMP levels. In the non-reproductive phase, when the E2/ERα levels were low, the inactivation of ERK1/2 and Akt-1 pathways favored apoptotic events due to an increase in the levels of Bax and cytochrome C, with a consequent regression of the gonad. Full article

(This article belongs to the Special Issue New Insights into Animal Spermatogenesis)

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13 pages, 2112 KiB

Open AccessArticle

The Effect of Single and Triple Testicular Biopsy Using Biopty Gun on Spermatogenesis in Pubertal Rats

by Tomislav Šušnjar, Ivana Kuzmić Prusac, Ivan Švagelj, Anđela Jurišić, Tomislav Šušnjar, Antonija Jurišić, Miro Jukić and Zenon Pogorelić

Animals 2021, 11(6), 1569; https://doi.org/10.3390/ani11061569 - 27 May 2021

Cited by 2 | Viewed by 5795

Abstract

Background: The aim of this study was to compare consequences in single and triple testicular biopsy by biopty gun in pubertal rats using histological and immunohistochemical analysis. Methods: Thirty-two Sprague-Dawley male rats were used as the experimental model. The rats were randomly divided [...] Read more.

Background: The aim of this study was to compare consequences in single and triple testicular biopsy by biopty gun in pubertal rats using histological and immunohistochemical analysis. Methods: Thirty-two Sprague-Dawley male rats were used as the experimental model. The rats were randomly divided into three study groups. The rats from the first group (n = 12) received a single-biopsy of upper pole of the left testis, while the rats from the second group (n = 10) received triple-biopsy of upper and lower poles and lateral surface of left testis. The third group (n = 10) was a control group. On the eightieth day after the biopsy in all rats bilateral orchiectomy and funiculectomy were performed to obtain testicular tissue and sperm for analysis. The consequences of the puncture were observed by pathohistology, immunohistochemistry and semen analysis. Results: The results of the study showed lower percentage of sperm count (14.5 mill/mL vs. 16 mill/mL, p = 0.130), sperm motility (24.6% vs. 32.7%, p > 0.05), abnormal sperm (30% vs. 27%, p > 0.05), atrophic tubules (21% vs. 6%, p < 0.001), volume (1.7 mL vs. 2.28 mL, p < 0.01) and apoptotic index (1.56 vs. 1.19, p = 0.650) in the testes with a triple-biopsy compared to the testes with a single-biopsy. Semen analysis showed a borderline significant difference between the group with triple-biopsy where sperm count was lower than it in the control group (14.5 mill/mL vs. 17.5 mill/mL, p = 0.05). A single-biopsy has little effect on the testis, especially on overall fertility. A triple-biopsy showed higher degree of the testicular damage but without a significant impact on overall fertility. Semen analysis showed that single- and triple-biopsies did not have a significant effect on sperm count, motility and morphology. Conclusion: Biopty gun procedure is a cheap, simple and reliable method for testicular biopsy in rats without a significant effect on sperm count, motility and morphology. Full article

(This article belongs to the Special Issue New Insights into Animal Spermatogenesis)

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14 pages, 3123 KiB

Open AccessArticle

Alkyphenol Exposure Alters Steroidogenesis in Male Lizard Podarcis siculus

by Mariana Di Lorenzo, Aldo Mileo, Vincenza Laforgia, Maria De Falco and Luigi Rosati

Animals 2021, 11(4), 1003; https://doi.org/10.3390/ani11041003 - 02 Apr 2021

Cited by 12 | Viewed by 1921

Abstract

Background: Nonylphenol (NP) and Octylphenol (OP) are persistent and non-biodegradable environmental contaminants classified as endocrine disruptor chemicals (EDCs). These compounds are widely used in several industrial applications and present estrogen-like properties, which have extensively been studied in aquatic organisms. The present study aimed [...] Read more.

Background: Nonylphenol (NP) and Octylphenol (OP) are persistent and non-biodegradable environmental contaminants classified as endocrine disruptor chemicals (EDCs). These compounds are widely used in several industrial applications and present estrogen-like properties, which have extensively been studied in aquatic organisms. The present study aimed to verify the interference of these compounds alone, and in mixture, on the reproductive cycle of the male terrestrial vertebrate Podarcis siculus, focusing mainly on the steroidogenesis process. Methods: Male lizards have been treated with different injections of both NP and OP alone and in mixture, and evaluation has been carried out using a histological approach. Results: Results obtained showed that both substances are able to alter both testis histology and localization of key steroidogenic enzymes, such as 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β- hydroxysteroid dehydrogenase (17β-HSD) and P450 aromatase. Moreover, OP exerts a preponderant effect, and the P450 aromatase represents the major target of both chemicals. Conclusions: In conclusion, NP and OP inhibit steroidogenesis, which in turn may reduce the reproductive capacity of the specimens. Full article

(This article belongs to the Special Issue New Insights into Animal Spermatogenesis)

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12 pages, 20363 KiB

Open AccessArticle

Preliminary Investigation on the Ameliorative Role Exerted by D-Aspartic Acid in Counteracting Ethane Dimethane Sulfonate (EDS) Toxicity in the Rat Testis

by Massimo Venditti, Maria Zelinda Romano, Francesco Aniello and Sergio Minucci

Animals 2021, 11(1), 133; https://doi.org/10.3390/ani11010133 - 08 Jan 2021

Cited by 14 | Viewed by 2552

Abstract

Herein is reported the first evidence of the protective role of D-aspartic acid (D-Asp) in preventing the toxic effect exerted by the alkylating agent ethane dimethane sulfonate (EDS) in the rat testis. We confirmed that EDS treatment specifically destroyed Leydig cells (LC), resulting [...] Read more.

Herein is reported the first evidence of the protective role of D-aspartic acid (D-Asp) in preventing the toxic effect exerted by the alkylating agent ethane dimethane sulfonate (EDS) in the rat testis. We confirmed that EDS treatment specifically destroyed Leydig cells (LC), resulting in the drastic decrease of the serum testosterone level and producing morphological changes in the germinal tubules, i.e., altered organization of the epithelium, loss of cell contacts and the consequent presence of empty spaces between them, and a reduce number of spermatozoa. Moreover, an increase of TUNEL-positive germ cells, other than alteration in the protein level and localization of two LC “markers”, StAR and PREP, were observed. Interestingly, results obtained from rats pre-treated with D-Asp for 15 days before EDS-injection showed that all the considered parameters were quite normal. To explore the probable mechanism(s) involved in the protection exerted by D-Asp, we considered the increased oxidative stress induced by EDS and the D-Asp antioxidant effects. Thiobarbiturc acid-reactive species (TBARS) levels increased following EDS-injection, while no change was observed in the D-Asp + EDS treated rats. Our results showed that D-Asp may be used as a strategy to mitigate the toxic effects exerted by environmental pollutants, as endocrine disrupters, in order to preserve the reproductive function. Full article

(This article belongs to the Special Issue New Insights into Animal Spermatogenesis)

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14 pages, 4466 KiB

Open AccessFeature PaperArticle

E4 Transcription Factor 1 (E4F1) Regulates Sertoli Cell Proliferation and Fertility in Mice

by Rong-Ge Yan, Qi-Lin Yang and Qi-En Yang

Animals 2020, 10(9), 1691; https://doi.org/10.3390/ani10091691 - 18 Sep 2020

Cited by 7 | Viewed by 3396

Abstract

In the mammalian testes, Sertoli cells are the only somatic cells in the seminiferous tubules that provide structural, nutritional and regulatory support for developing spermatogenic cells. Sertoli cells only proliferate during the fetal and neonatal periods and enter a quiescent state after puberty. [...] Read more.

In the mammalian testes, Sertoli cells are the only somatic cells in the seminiferous tubules that provide structural, nutritional and regulatory support for developing spermatogenic cells. Sertoli cells only proliferate during the fetal and neonatal periods and enter a quiescent state after puberty. Functional evidences suggest that the size of Sertoli cell population determines sperm production and fertility. However, factors that direct Sertoli cell proliferation and maturation are not fully understood. Transcription factor E4F1 is a multifunctional protein that serves essential roles in cell fate decisions and because it interacts with pRB, a master regulator of Sertoli cell function, we hypothesized that E4F1 may have a functional role in Sertoli cells. E4f1 mRNA was present in murine testis and immunohistochemical staining confirmed that E4F1 was enriched in mature Sertoli cells. We generated a conditional knockout mouse model using Amh-cre and E4f1^flox/flox lines to study E4F1 fucntion in Sertoli cells and the results showed that E4f1 deletion caused a significant reduction in testis size and fertility. Further analyses revealed that meiosis progression and spermiogenesis were normal, however, Sertoli cell proliferation was impaired and germ cell apoptosis was elevated in the testis of E4f1 conditional knockout mice. On the basis of these findings, we concluded that E4F1 was expressed in murine Sertoli cells and served important functions in regulating Sertoli cell proliferation and fertility. Full article

(This article belongs to the Special Issue New Insights into Animal Spermatogenesis)

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Review

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12 pages, 1754 KiB

Open AccessReview

The Aromatase–Estrogen System in the Testes of Non-Mammalian Vertebrates

by Luigi Rosati, Sara Falvo, Gabriella Chieffi Baccari, Alessandra Santillo and Maria Maddalena Di Fiore

Animals 2021, 11(6), 1763; https://doi.org/10.3390/ani11061763 - 12 Jun 2021

Cited by 14 | Viewed by 4483

Abstract

Estrogens are important physiological regulators of testicular activity in vertebrates. Estrogen levels depend on the activity of P450 aromatase, the enzyme responsible for the irreversible conversion of testosterone into 17β-estradiol. Therefore, P450 aromatase is the key player in the aromatase–estrogen system. The present [...] Read more.

Estrogens are important physiological regulators of testicular activity in vertebrates. Estrogen levels depend on the activity of P450 aromatase, the enzyme responsible for the irreversible conversion of testosterone into 17β-estradiol. Therefore, P450 aromatase is the key player in the aromatase–estrogen system. The present review offers a comparative overview of P450 aromatase activity in male gonads of amphibians, reptiles, and birds, with a particular emphasis on the functions of the aromatase–estrogen system in these organisms during their developmental and adult stages. The aromatase–estrogen system appears to be crucial for the sex differentiation of gonads in vertebrates. Administration of aromatase inhibitors prior to sexual differentiation of gonads results in the development of males rather than females. In adults, both aromatase and estrogen receptors are expressed in somatic cells, Leydig and Sertoli cells, as well as germ cells, with certain differences among different species. In seasonal breeding species, the aromatase–estrogen system serves as an “on/off” switch for spermatogenesis. In some amphibian and reptilian species, increased estrogen levels in post-reproductive testes are responsible for blocking spermatogenesis, whereas, in some species of birds, estrogens function synergistically with testosterone to promote spermatogenesis. Recent evidence indicates that the production of the aromatase enzyme in excessive amounts reduces the reproductive performance in avian species of commercial interest. The use of aromatase inhibitors to improve fertility has yielded suitable positive results. Therefore, it appears that the role of the aromatase–estrogen system in regulating the testicular activity differs not only among the different classes of vertebrates but also among different species within the same class. Full article

(This article belongs to the Special Issue New Insights into Animal Spermatogenesis)

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17 pages, 993 KiB

Open AccessReview

Spermatogonial Stem Cell Transplantation in Large Animals

by Xin Zhao, Weican Wan, Xianyu Zhang, Zhenfang Wu and Huaqiang Yang

Animals 2021, 11(4), 918; https://doi.org/10.3390/ani11040918 - 24 Mar 2021

Cited by 10 | Viewed by 3711

Abstract

Spermatogonial stem cell transplantation (SSCT) can restore male fertility through transfer of germline between donor and recipient males. From an agricultural perspective, SSCT could be an important next-generation reproductive and breeding tool in livestock production. Current SSCT approaches in large animals remain inefficient [...] Read more.

Spermatogonial stem cell transplantation (SSCT) can restore male fertility through transfer of germline between donor and recipient males. From an agricultural perspective, SSCT could be an important next-generation reproductive and breeding tool in livestock production. Current SSCT approaches in large animals remain inefficient and many technical details need further investigation. This paper reviews the current knowledge on SSCT in large animals, addressing (1) donor spermatogonial stem cell (SSC) preparation, (2) recipient male treatment, and (3) SSC injection, homing, and detection. The major studies showing unequivocal evidence of donor SSC-derived spermatogenesis in large animals (mainly in livestock for breeding purpose) are summarized to discuss the current status of the field and future directions. Full article

(This article belongs to the Special Issue New Insights into Animal Spermatogenesis)

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