Testicular descent, sperm maturation and capacitation. Lessons from our most distant relatives, the monotremes

The present review examines whether monotremes may help to resolve three questions relating to sperm production in mammals: why the testes descend into a scrotum in most mammals, why spermatozoa are infertile when they leave the testes and require a period of maturation in the specific milieu provided by the epididymides, and why ejaculated spermatozoa cannot immediately fertilise an ovum until they undergo capacitation within the female reproductive tract. Comparisons of monotremes with other mammals indicate that there is a need for considerable work on monotremes. It is hypothesised that testicular descent should be related to epididymal differentiation. Spermatozoa and ova from both groups share many of the proteins that are thought to be involved in gamete interaction, and although epididymal sperm maturation is significant it is probably less complex in monotremes than in other mammals. However, the monotreme epididymis is unique in forming spermatozoa into bundles of 100 with greatly enhanced motility compared with individual spermatozoa. Bundle formation involves a highly organised interaction with epididymal proteins, and the bundles persist during incubation in vitro, except in specialised medium, in which spermatozoa separate after 2–3 h incubation. It is suggested that this represents an early form of capacitation.

Download Full-text

Caput Ligation Renders Immature Mouse Sperm Motile and Capable to Undergo cAMP-Dependent Phosphorylation

International Journal of Molecular Sciences ◽

10.3390/ijms221910241 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10241

Author(s):

Darya A. Tourzani ◽

Maria A. Battistone ◽

Ana M. Salicioni ◽

Sylvie Breton ◽

Pablo E. Visconti ◽

...

Keyword(s):

Reproductive Tract ◽

Female Reproductive Tract ◽

Sperm Maturation ◽

Molecular Pathways ◽

Epididymal Sperm ◽

Mammalian Sperm ◽

Maturation In Vitro ◽

Epididymal Maturation ◽

Immature Mouse

Mammalian sperm must undergo two post-testicular processes to become fertilization-competent: maturation in the male epididymis and capacitation in the female reproductive tract. While caput epididymal sperm are unable to move and have not yet acquired fertilization potential, sperm in the cauda epididymis have completed their maturation, can move actively, and have gained the ability to undergo capacitation in the female tract or in vitro. Due to the impossibility of mimicking sperm maturation in vitro, the molecular pathways underlying this process remain largely unknown. We aimed to investigate the use of caput epididymal ligation as a tool for the study of sperm maturation in mice. Our results indicate that after seven days of ligation, caput sperm gained motility and underwent molecular changes comparable with those observed for cauda mature sperm. Moreover, ligated caput sperm were able to activate pathways related to sperm capacitation. Despite these changes, ligated caput sperm were unable to fertilize in vitro. Our results suggest that transit through the epididymis is not required for the acquisition of motility and some capacitation-associated signaling but is essential for full epididymal maturation. Caput epididymal ligation is a useful tool for the study of the molecular pathways involved in the acquisition of sperm motility during maturation.

Download Full-text

In vivo exposure to 17β-estradiol triggers premature sperm capacitation in cauda epididymis

Reproduction ◽

10.1530/rep-12-0472 ◽

2013 ◽

Vol 145 (3) ◽

pp. 255-263 ◽

Cited By ~ 14

Author(s):

Lukas Ded ◽

Natasa Sebkova ◽

Martina Cerna ◽

Fatima Elzeinova ◽

Pavla Dostalova ◽

...

Keyword(s):

Reproductive Tract ◽

Negative Impact ◽

Reproductive Potential ◽

Female Reproductive Tract ◽

Sperm Capacitation ◽

Epididymal Sperm ◽

Knock Out ◽

17Β Estradiol

Estrogens play a crucial role in spermatogenesis and estrogen receptor α knock-out male mice are infertile. It has been demonstrated that estrogens significantly increase the speed of capacitation in vitro; however this may lead to the reduction of reproductive potential due to the decreased ability of these sperm to undergo the acrosome reaction. To date the in vivo effect of estrogens on the ability of sperm to capacitate has not been investigated. Therefore, in this study, we exposed mice (n=24) to 17β-estradiol (E2) at the concentration of 20 ng/ml either during puberty from the fourth to seventh week of age (n=8), or continuously from birth for a period of 12 weeks (n=8) at which age the animals from both groups were killed. The capacitation status of epididymal and testicular sperm was analysed by tyrosine phosphorylation (TyrP) antibody (immunofluorescence and western blot) and chlortetracycline (CTC) assay. According to our results, in vivo exposure to increased E2 concentrations caused premature sperm capacitation in the epididymis. The effect of E2, however, seems reversible because after the termination of the exposure premature epididymal sperm capacitation is decreased in animals treated during puberty. Furthermore the changes in epididymal sperm capacitation status detected by TyrP and CTC positively correlate with plasma levels of E2 and the expression of the estrogen-dependent trefoil factor 1 (Tff1) gene in testicular tissue. Therefore, our data implicate that in vivo exposure to E2 under specific conditions leads to the premature capacitation of mouse sperm in epididymis with a potential negative impact on the sperm reproductive fitness in the female reproductive tract.

Download Full-text

Organoids of the female reproductive tract

Journal of Molecular Medicine ◽

10.1007/s00109-020-02028-0 ◽

2021 ◽

Vol 99 (4) ◽

pp. 531-553 ◽

Cited By ~ 1

Author(s):

Cindrilla Chumduri ◽

Margherita Y. Turco

Keyword(s):

Reproductive Tract ◽

Personalised Medicine ◽

Three Dimensional ◽

In Vitro Models ◽

Experimental Models ◽

Female Reproductive Tract ◽

Cellular Heterogeneity ◽

Dynamic Regulation ◽

Pregnancy And Childbirth

AbstractHealthy functioning of the female reproductive tract (FRT) depends on balanced and dynamic regulation by hormones during the menstrual cycle, pregnancy and childbirth. The mucosal epithelial lining of different regions of the FRT—ovaries, fallopian tubes, uterus, cervix and vagina—facilitates the selective transport of gametes and successful transfer of the zygote to the uterus where it implants and pregnancy takes place. It also prevents pathogen entry. Recent developments in three-dimensional (3D) organoid systems from the FRT now provide crucial experimental models that recapitulate the cellular heterogeneity and physiological, anatomical and functional properties of the organ in vitro. In this review, we summarise the state of the art on organoids generated from different regions of the FRT. We discuss the potential applications of these powerful in vitro models to study normal physiology, fertility, infections, diseases, drug discovery and personalised medicine.

Download Full-text

Zinc: A Necessary Ion for Mammalian Sperm Fertilization Competency

International Journal of Molecular Sciences ◽

10.3390/ijms19124097 ◽

2018 ◽

Vol 19 (12) ◽

pp. 4097 ◽

Cited By ~ 19

Author(s):

Karl Kerns ◽

Michal Zigo ◽

Peter Sutovsky

Keyword(s):

Male Fertility ◽

Reproductive Tract ◽

Zinc Supplementation ◽

Female Reproductive Tract ◽

Sperm Maturation ◽

Cellular Mechanisms ◽

Human Reproductive ◽

Semen Processing ◽

New Research ◽

And Function

The importance of zinc for male fertility only emerged recently, being propelled in part by consumer interest in nutritional supplements containing ionic trace minerals. Here, we review the properties, biological roles and cellular mechanisms that are relevant to zinc function in the male reproductive system, survey available peer-reviewed data on nutritional zinc supplementation for fertility improvement in livestock animals and infertility therapy in men, and discuss the recently discovered signaling pathways involving zinc in sperm maturation and fertilization. Emphasis is on the zinc-interacting sperm proteome and its involvement in the regulation of sperm structure and function, from spermatogenesis and epididymal sperm maturation to sperm interactions with the female reproductive tract, capacitation, fertilization, and embryo development. Merits of dietary zinc supplementation and zinc inclusion into semen processing media are considered with livestock artificial insemination (AI) and human assisted reproductive therapy (ART) in mind. Collectively, the currently available data underline the importance of zinc ions for male fertility, which could be harnessed to improve human reproductive health and reproductive efficiency in agriculturally important livestock species. Further research will advance the field of sperm and fertilization biology, provide new research tools, and ultimately optimize semen processing procedures for human infertility therapy and livestock AI.

Download Full-text

Spermatozoa Obtained From Alpaca vas deferens. Effects of Seminal Plasma Added at Post-thawing

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.611301 ◽

2021 ◽

Vol 8 ◽

Author(s):

Eduardo G. Aisen ◽

Wilfredo Huanca López ◽

Manuel G. Pérez Durand ◽

Edita Torres Mamani ◽

Juan C. Villanueva Mori ◽

...

Keyword(s):

Seminal Plasma ◽

Artificial Insemination ◽

Reproductive Tract ◽

Vas Deferens ◽

Female Reproductive Tract ◽

Low Fertility ◽

Sperm Cells ◽

South American Camelids ◽

Thawing Process

The viscous seminal plasma (SP) is currently a major impediment to the handling of ejaculate and the development of some biotechnologies in South American camelids. The vas deferens-collected spermatozoa of alpacas is a useful technique to avoid this problem. On the other hand, SP contains a large protein component that has been implicated in the function of spermatozoa within the female reproductive tract. In this sense, the low fertility achieved using transcervical insemination with frozen-thawed spermatozoa in alpacas could be improved by adding SP. This study aimed to evaluate the effect of the whole SP on some in vitro parameters of alpaca spermatozoa after the freezing-thawing-process and the fertility after artificial insemination. It would contribute to a better understanding of the interaction between thawed sperm cells and SP. Spermatozoa were obtained by surgically diverted vas deferens. The samples were diluted with a Tris-based extender, packaged in straws, and frozen. At thawing, each straw was divided into two post-thawing conditions: with the addition of 10% of PBS (control) or with 10% SP (treatment). The sperm cells were evaluated using dynamic parameters, sperm cell morphology, and morphometry. Fertility was assessed by an artificial insemination trial. All in vitro parameters were analyzed by ANOVA. A heterogeneity test was scheduled for the fertility trial. After the freezing-thawing process, motility and plasma membrane functionality was improved when SP was added. No differences were found for post-thaw viability between the control and treatment samples. The percentage of normal cells was higher with SP at post-thawing, and a decrease of the presence of bent tailed spermatozoa with a droplet in the SP group was observed. The length of the head spermatozoa was 3.4% higher in the samples with PBS compared to those in which SP was added. Females pregnant at day 25 post-insemination were 0/12 (with SP inside the straw) and 1/10 (without SP inside the straw). In conclusion, the presence of 10% SP at post-thawing improves sperm cells' motility, functionality, and morphology, indicating that it would be beneficial to improve the frozen-thawed alpaca's physiology spermatozoa. More fertility trials must be developed to increase this knowledge.

Download Full-text

Development of parthenogenetic and fertilized mouse embryos in the uterus and in extra-uterine sites

Development ◽

10.1242/dev.34.2.387 ◽

1975 ◽

Vol 34 (2) ◽

pp. 387-405

Author(s):

S. A. Iles ◽

M. W. McBurney ◽

S. R. Bramwell ◽

Z. A. Deussen ◽

C. F. Graham

Keyword(s):

Reproductive Tract ◽

Neural Tissue ◽

Cell Types ◽

Mouse Embryos ◽

Female Reproductive Tract ◽

Embryonic Cells ◽

Haploid Embryos ◽

Keratinized Epithelium ◽

Mouse Eggs

Mouse eggs were activated with hyaluronidase in vitro and subsequently transferred to the oviduct. In the female reproductive tract they formed morulae and blastocysts which died soon after implantation. Haploid blastocysts were transferred beneath the kidney capsule and here some formed disorganized egg-cylinder structures in a week. Morulae and blastocysts from haploid and diploid parthenogenones were also transferred beneath the testis capsule. Two to four months later the growths which had formed were sectioned. They contained neural tissue, pigment, keratinized epithelium, glandular epithelium, ciliated epithelium, cartilage, bone, muscle, adipose tissue, and haemopoietic tissue. The range of cell types was similar to that produced by fertilized control blastocysts except that the parthenogenones did not form identifiable yolk-sac carcinoma or embryonal carcinomacells. The growths from haploid and diploid parthenogenones in the testis were stained with Feulgen and their DNA content measured. Growths from diploid embryos contained the normal diploid amount of DNA while growths from haploid embryos contained less than this amount. Cell cultures were prepared from the growths. The cells which were investigated contained no Y chromosome, suggesting that they were derived from the embryonic cells rather than the cells of the male host. These cells contained a near diploid chromosome number, although some of them were originally derived from haploid embryos.

Download Full-text

CatSperζ regulates the structural continuity of sperm Ca2+ signaling domains and is required for normal fertility

eLife ◽

10.7554/elife.23082 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 54

Author(s):

Jean-Ju Chung ◽

Kiyoshi Miki ◽

Doory Kim ◽

Sang-Hee Shim ◽

Huanan F Shi ◽

...

Keyword(s):

Reproductive Tract ◽

Female Reproductive Tract ◽

Targeted Disruption ◽

Vitro Fertilization ◽

Male Subfertility ◽

Epididymal Spermatozoa ◽

Mammalian Female ◽

Signaling Domains

We report that the Gm7068 (CatSpere) and Tex40 (CatSperz) genes encode novel subunits of a 9-subunit CatSper ion channel complex. Targeted disruption of CatSperz reduces CatSper current and sperm rheotactic efficiency in mice, resulting in severe male subfertility. Normally distributed in linear quadrilateral nanodomains along the flagellum, the complex lacking CatSperζ is disrupted at ~0.8 μm intervals along the flagellum. This disruption renders the proximal flagellum inflexible and alters the 3D flagellar envelope, thus preventing sperm from reorienting against fluid flow in vitro and efficiently migrating in vivo. Ejaculated CatSperz-null sperm cells retrieved from the mated female uterus partially rescue in vitro fertilization (IVF) that failed with epididymal spermatozoa alone. Human CatSperε is quadrilaterally arranged along the flagella, similar to the CatSper complex in mouse sperm. We speculate that the newly identified CatSperζ subunit is a late evolutionary adaptation to maximize fertilization inside the mammalian female reproductive tract.

Download Full-text

301 THE EFFECT OF EQUINE FOLICULLAR FLUID ON IN VITRO INDUCTION OF THE ACROSOME REACTION IN FROZEN - THAWED STALLION SPERMATOZOA

Reproduction Fertility and Development ◽

10.1071/rdv22n1ab301 ◽

2010 ◽

Vol 22 (1) ◽

pp. 307

Author(s):

D. S. Silva ◽

P. Rodriguez ◽

N. S. Arruda ◽

R. Rodrigues ◽

J. L. Rodrigues

Keyword(s):

Contact Area ◽

Follicular Fluid ◽

Acrosome Reaction ◽

Reproductive Tract ◽

Female Reproductive Tract ◽

Heparin Group ◽

Fluorescent Stain ◽

In Vitro Induction

The capacitation process occurs in vivo upon exposure of the spermatozoa through the female reproductive tract, but can be induced in vitro in the presence of several compounds. This study was conducted to assess the effect of heparin or equine follicular fluid on hyperactivated motility and in vitro induction acrosome reaction swim-up method with frozen-thawed stallion semen. Two hundred microliters of frozen-thawed equine semen was placed in a tube (45°C) to increase contact area and incubated at 37°C for 1 h. After incubation 800 μL of the supernatant was collected by centrifugation (500 × g, 10 min) to collect spermatozoa. The resulting pellet was resuspended in capacitation medium Fert-TALP supplemented with 5.0 μg mL-1 heparin or 100% follicular fluid and incubated for different times (1, 2, 3, 4, and 5 h) at 37°C. After incubation the hyperactivated motility and acrosome-reacted spermatozoa were evaluated. Hoechst stain was used to differentiate live and dead spermatozoa, and chlortetracycline (CTC) fluorescent stain was used to assess the capacitation response of sperm; data were analyzed by ANOVA. The effect of equine follicular fluid resulted in improved percentage of spermatozoa with acrosome reaction at all times of incubation (60, 63, 57, 52, and 58%) but immediately after 3 h of incubation, the hyperactivated motility decreased in heparin group and follicular fluid (42 and 30%, respectively).

Download Full-text

ESR1 Mutations Associated With Estrogen Insensitivity Syndrome Change Conformation of Ligand-Receptor Complex and Altered Transcriptome Profile

Endocrinology ◽

10.1210/endocr/bqaa050 ◽

2020 ◽

Vol 161 (6) ◽

Cited By ~ 1

Author(s):

Yin Li ◽

Katherine J Hamilton ◽

Lalith Perera ◽

Tianyuan Wang ◽

Artiom Gruzdev ◽

...

Keyword(s):

Molecular Mechanisms ◽

Reproductive Tract ◽

Biological Effects ◽

Estrogen Receptor Α ◽

Female Reproductive Tract ◽

Receptor Complexes ◽

Esr1 Gene ◽

Esr1 Mutations

Abstract Estrogen insensitivity syndrome (EIS) arises from rare mutations in estrogen receptor-α (ERα, encoded by ESR1 gene) resulting in the inability of estrogen to exert its biological effects. Due to its rarity, mutations in ESR1 gene and the underlying molecular mechanisms of EIS have not been thoroughly studied. Here, we investigate known ESR1 mutants, Q375H and R394H, associated with EIS patients using in vitro and in vivo systems. Comparison of the transcriptome and deoxyribonucleic acid methylome from stable cell lines of both Q375H and R394H clinical mutants shows a differential profile compared with wild-type ERα, resulting in loss of estrogen responsiveness. Molecular dynamic simulation shows that both ESR1 mutations change the ERα conformation of the ligand-receptor complexes. Furthermore, we generated a mouse model Esr1-Q harboring the human mutation using CRISPR/Cas9 genome editing. Female and male Esr1-Q mice are infertile and have similar phenotypes to αERKO mice. Overall phenotypes of the Esr1-Q mice correspond to those observed in the patient with Q375H. Finally, we explore the effects of a synthetic progestogen and a gonadotropin-releasing hormone inhibitor in the Esr1-Q mice for potentially reversing the impaired female reproductive tract function. These findings provide an important basis for understanding the molecular mechanistic consequences associated with EIS.

Download Full-text

Phytochemical Composition and In Vitro Antimicrobial Activity of Essential Oils from the Lamiaceae Family against Streptococcus agalactiae and Candida albicans Biofilms

Antibiotics ◽

10.3390/antibiotics9090592 ◽

2020 ◽

Vol 9 (9) ◽

pp. 592

Author(s):

Ramona Iseppi ◽

Roberta Tardugno ◽

Virginia Brighenti ◽

Stefania Benvenuti ◽

Carla Sabia ◽

...

Keyword(s):

Antimicrobial Activity ◽

Candida Albicans ◽

Essential Oils ◽

Streptococcus Agalactiae ◽

Reproductive Tract ◽

Bacterial Species ◽

Female Reproductive Tract ◽

Retention Data ◽

Natural Defense

The antimicrobial activity of different essential oils (EOs) from the Lamiaceae family was evaluated on Streptococcus agalactiae, Candida albicans, and lactobacilli. S. agalactiae is the main cause of severe neonatal infections, such as sepsis, meningitis, and pneumonia. C. albicans is a primary causative agent of vulvovaginal candidiasis, a multifactorial infectious disease of the lower female reproductive tract. Lactobacilli represent the dominant bacterial species of the vaginal flora and constitute the natural defense against pathogens. On the basis of the preliminary results, the attention was focused on the EOs from Lavandula x intermedia Emeric ex Loisel. and Mentha arvensis L. By using gas ghromatography (GS) retention data and mass spectra, it was possible to identify more than 90% of the total composition of the EO samples. The minimal inhibitory concentration (MIC) and anti-biofilm activity of the two EOs were determined against all isolated strains, using the EOs by themselves or in combination with each other and with drugs (erythromycin and fluconazole). The results showed a good antimicrobial and anti-biofilm activity of both EOs and a synergistic effect, leading to the best results against all the strains, resulted using the combinations EOs/EOs and antimicrobials/EOs.

Download Full-text