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

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.

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

Reproduction Fertility and Development ◽

10.1071/rd09081 ◽

2009 ◽

Vol 21 (8) ◽

pp. 992 ◽

Cited By ~ 5

Author(s):

Heath Ecroyd ◽

Brett Nixon ◽

Jean-Louis Dacheux ◽

Russell C. Jones

Keyword(s):

Reproductive Tract ◽

Female Reproductive Tract ◽

Sperm Maturation ◽

Present Review ◽

Testicular Descent ◽

Sperm Production ◽

Epididymal Sperm ◽

Early Form ◽

Considerable Work

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.

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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.

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Integration of Sperm Motility and Chemotaxis Screening with a Microchannel-Based Device

Clinical Chemistry ◽

10.1373/clinchem.2010.146902 ◽

2010 ◽

Vol 56 (8) ◽

pp. 1270-1278 ◽

Cited By ~ 62

Author(s):

Lan Xie ◽

Rui Ma ◽

Chao Han ◽

Kai Su ◽

Qiufang Zhang ◽

...

Keyword(s):

Sperm Motility ◽

Reproductive Tract ◽

Cumulus Cells ◽

Female Reproductive Tract ◽

Straight Channel ◽

Vitro Fertilization ◽

Mammalian Sperm ◽

Reaction Capability ◽

Mammalian Female

BACKGROUND Sperm screening is an essential step in in vitro fertilization (IVF) procedures. The swim-up method, an assay for sperm motility, is used clinically to select the ideal sperm for subsequent manipulation. However, additional parameters, including acrosome reaction capability, chemotaxis, and thermotaxis, are also important indicators of mammalian sperm health. To monitor both sperm motility and chemotaxis simultaneously during sperm screening, we designed and constructed a microdevice comprising a straight channel connected with a bibranch channel that mimics the mammalian female reproductive tract. METHODS The width and length of the straight channel were optimized to select the motile sperms. We selectively cultured cumulus cells in the bibranch channel to generate a chemoattractant-forming chemical gradient. Sperm chemotaxis was represented by the ratio of the sperm swimming toward different branches. RESULTS The percentage of motile sperms improved from 58.5% (3.8%) to 82.6% (2.9%) by a straight channel 7 mm in length and 1 mm in width. About 10% of sperms were found to be chemotactically responsive in our experiment, which is consistent with previous studies. CONCLUSIONS For the first time, we achieved the combined evaluation of both sperm motility and chemotaxis. The motile and chemotactically responsive sperms can easily be enriched on a lab-on-a-chip device to improve IVF outcome.

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Peroxiredoxin 6: The Protector of Male Fertility

Antioxidants ◽

10.3390/antiox7120173 ◽

2018 ◽

Vol 7 (12) ◽

pp. 173 ◽

Cited By ~ 10

Author(s):

Cristian O’Flaherty

Keyword(s):

Reproductive Tract ◽

Female Reproductive Tract ◽

Antioxidant Protection ◽

Paternal Genome ◽

Complex Process ◽

Epididymal Maturation ◽

Primary Antioxidant ◽

Calcium Independent Phospholipase A2

The spermatozoon is a terminal cell with the unique purpose of delivering the paternal genome to the oocyte during fertilization. Once spermatozoa enter into the female reproductive tract, they count on only the antioxidant protection that they received during spermatogenesis and epididymal maturation. Peroxiredoxins (PRDXs), particularly PRDX6, are important players in the antioxidant protection and regulation of reactive oxygen species (ROS) levels in spermatozoa. PRDX6, through its peroxidase and calcium-independent phospholipase A2 activities, plays a major role in the regulation of ROS to maintain viability and motility and allow the spermatozoon to achieve fertilizing ability during the complex process of capacitation. The absence of PRDX6 is sufficient to promote abnormal reproductive outcomes in mice that resemble what we observe in infertile men. Indeed, Prdx6−/− spermatozoa display low motility and severe DNA damage, which is translated into reduced ability to fertilize oocytes in vitro or produce a low number of pups compared to wild-type controls. This review focuses on the role of PRDX6 as the primary antioxidant enzyme that protects the spermatozoon from oxidative-stress-associated damages to protect the paternal genome and assure fertility.

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SLO3 auxiliary subunit LRRC52 controls gating of sperm KSPER currents and is critical for normal fertility

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1423869112 ◽

2015 ◽

Vol 112 (8) ◽

pp. 2599-2604 ◽

Cited By ~ 28

Author(s):

Xu-Hui Zeng ◽

Chengtao Yang ◽

Xiao-Ming Xia ◽

Min Liu ◽

Christopher J. Lingle

Keyword(s):

Reproductive Tract ◽

Mammalian Species ◽

Critical Role ◽

Membrane Conductance ◽

Female Reproductive Tract ◽

Vitro Fertilization ◽

Mammalian Sperm ◽

Auxiliary Subunit ◽

Common Facet

Following entry into the female reproductive tract, mammalian sperm undergo a maturation process termed capacitation that results in competence to fertilize ova. Associated with capacitation is an increase in membrane conductance to both Ca2+ and K+, leading to an elevation in cytosolic Ca2+ critical for activation of hyperactivated swimming motility. In mice, the Ca2+ conductance (alkalization-activated Ca2+-permeable sperm channel, CATSPER) arises from an ensemble of CATSPER subunits, whereas the K+ conductance (sperm pH-regulated K+ current, KSPER) arises from a pore-forming ion channel subunit encoded by the slo3 gene (SLO3) subunit. In the mouse, both CATSPER and KSPER are activated by cytosolic alkalization and a concerted activation of CATSPER and KSPER is likely a common facet of capacitation-associated increases in Ca2+ and K+ conductance among various mammalian species. The properties of heterologously expressed mouse SLO3 channels differ from native mouse KSPER current. Recently, a potential KSPER auxiliary subunit, leucine-rich-repeat-containing protein 52 (LRRC52), was identified in mouse sperm and shown to shift gating of SLO3 to be more equivalent to native KSPER. Here, we show that genetic KO of LRRC52 results in mice with severely impaired fertility. Activation of KSPER current in sperm lacking LRRC52 requires more positive voltages and higher pH than for WT KSPER. These results establish a critical role of LRRC52 in KSPER channels and demonstrate that loss of a non-pore-forming auxiliary subunit results in severe fertility impairment. Furthermore, through analysis of several genotypes that influence KSPER current properties we show that in vitro fertilization competence correlates with the net KSPER conductance available for activation under physiological conditions.

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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.

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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.

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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.

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Cytosine methylation dynamics during post-testicular sperm maturation in mammals

10.1101/2020.02.14.949487 ◽

2020 ◽

Author(s):

Carolina Galan ◽

Ryan W. Serra ◽

Fengyun Sun ◽

Vera D. Rinaldi ◽

Colin C. Conine ◽

...

Keyword(s):

Germ Cell ◽

Cytosine Methylation ◽

Reproductive Tract ◽

Extracellular Dna ◽

Cell Populations ◽

Epididymal Sperm ◽

Sequencing Data ◽

Testicular Germ Cell ◽

Mammalian Sperm ◽

The Stability

ABSTRACTBeyond the haploid genome, mammalian sperm contribute a payload of epigenetic information which can modulate offspring phenotypes. Recent studies have shown that the small RNA payload of sperm undergoes extensive remodeling during post-testicular maturation in the epididymis. Intriguingly, epididymal maturation has also been linked to changes in the sperm methylome, suggesting that the epididymis might play a broader role in remodeling the sperm epigenome. Here, we build on prior studies of the maturing sperm methylation landscape, further characterizing the genome-wide methylation landscape in seven germ cell populations collected from throughout the male reproductive tract. Overall, we find very few changes in the cytosine methylation landscape between testicular germ cell populations and cauda epididymal sperm, demonstrating that the sperm methylome is largely stable throughout post-testicular maturation. Intriguingly, although our sequencing data suggested that caput epididymal sperm exhibit a highly unusual methylome, follow-up studies revealed that this resulted from contamination of caput sperm by extracellular DNA. Extracellular DNA formed web-like structures that ensnared sperm, was present only in the caput epididymis of virgin males, where it was associated with citrullinated histone H3 and presumably resulted from a PAD-driven genome decondensation process. Taken together, our data emphasize the stability of the cytosine methylation landscape in mammalian sperm, and identify a surprising but transient period during which immature sperm are associated with extracellular DNA.

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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.

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