The End of Anonymous Sperm Donation in Colorado: A Step Forward to a New Fertility Future in the US?

This Viewpoint discusses the new Colorado law prohibiting anonymous gamete donation and other debates over reproductive technologies and secrecy.

Outcome prediction of microdissection testicular sperm extraction based on extracellular vesicles piRNAs

PURPOSE

Microdissection testicular sperm extraction (micro-TESE) could retrieve sperm from the testicles to help the non-obstructive azoospermia (NOA) patients to get their biological children, but also would cause damage to the testicles. Therefore, it is necessary to preoperatively predict the micro-TESE outcome in NOA patients. For this purpose, we aim to develop a model based on extracellular vesicles' (EVs) piRNAs (EV-piRNAs) in seminal plasma.

METHODS

To identify EV-piRNAs that were associated with spermatogenic ability, small RNA-seq was performed between the NOA group (n = 8) and normal group (n = 8). Validation of EV-piRNA expression in seminal plasma EVs and testicles tissues was used to select EV-piRNAs for the model. Candidate EV-piRNAs were further selected by LASSO regression analysis. Binary logistic regression analysis was used for the models' calculation formula. ROC analysis and Hosmer-Lemeshow test was used to assess the models' performance in the training (n = 20) and validation (n = 25) cohorts.

RESULTS

We identified 8 EV-piRNAs which were associated with spermatogenic ability. Two EV-piRNAs (pir-60351 and pir-61927) were selected by LASSO regression analysis. Finally, we developed a favorable model based on the expression of pir-61927 with good discrimination wherein the AUC was 0.82 (95% CI: 0.63~1.00, p = 0.016) in the training cohort and 0.83 (95% CI: 0.66~1.00, p = 0.005) in the validation cohort, as well as good calibration.

CONCLUSIONS

A favorable model based on the expression of pir-61927 in seminal plasma EVs was established to predict the micro-TESE outcome in NOA patients.

Clinical outcomes following ICSI cycles using surgically recovered sperm and the impact of maternal age: 2004-2015 SART CORS registry

PURPOSE

The aims of this study were (1) to evaluate clinical outcomes after ICSI cycles using surgically recovered sperm and (2) to assess the influence of maternal age on those outcomes.

METHODS

A retrospective cohort study of 24,763 IVF cycles of fresh autologous oocytes and ICSI using surgically recovered sperm reported to the SART CORS database from 2004 to 2015.

RESULTS AND CONCLUSIONS

Older women had significantly longer stimulation (p < 0.001), a lower number of oocytes retrieved (p < 0.001), a lower number of 2PN zygotes (p < 0.001), a lower chance of having a blastocyst transferred (p < 0.001), and a higher number of fresh embryos transferred (p < 0.001). There was no significant association between the number of 2PNs per oocyte retrieved and maternal age (p = 0.214). Both clinical pregnancy rates and live birth rates (LBR) decreased with advanced maternal age (p < 0.001). LBR ranged from 50.4% in women < 30 to 7.2% in women > 42 years, and for cleavage-stage transfers, the LBR ranged from 47.3% in women< 30 to 6.3% in women > 42 years. There were no differences in gestational age at delivery, proportion of term deliveries, preterm deliveries, neonatal birth weight < 2500 g, neonatal birth weight > 4000 g and average birthweight of neonates for singleton pregnancies according to age. For twin pregnancies, women < 30 years had significantly higher number of live births, term deliveries, and lower preterm deliveries than older women. There was a similar number of female (6051) and male neonates (5858; p = 0.2). Overall, pregnancy outcomes with ICSI using surgically recovered sperm are reassuring and comparable to those of ICSI with ejaculated sperm.

Cell-Based Therapies in Acute Kidney Injury (AKI)

Acute kidney injury frequently occurs in hospitalized patients all over the world. The prognosis remains poor since specific therapies for promoting kidney regeneration/repair are still missing. In recent years cell-based strategies have improved AKI outcomes under experimental circumstances. Four groups of cells, each of them displaying certain biological and functional characteristics have been evaluated in AKI, induced Pluripotent Stem Cells (iPSCs), Spermatagonial Stem Cells (SSCs), Proangiogenic Cells (PACs) and Endothelial Colony Forming Cells (ECFCs), and Mesenchymal Stem Cells (MSCs). All of these have been documented to stabilize either parameters of kidney excretory dysfunction and/or certain morphological parameters. The mechanisms responsible for AKI protection include direct (cell incorporation) and indirect processes, the latter being mediated by humoral factors and particularly by the production of so-called extracellular vesicles. Cell-derived vesicular organelles have been shown to carry pro-regenerative micro-RNA molecules which stabilize the vascular and tubular function. The first trials in humans have been initiated, the majority of such trials employs MSCs. However, any transfer of cell-based strategies in the clinical practice is potentially associated with significant difficulties. These include cell availability, tolerance and competence. The article intends to summarize essential informations about all of the four populations mentioned above and to discuss implications for the management of human AKI.

Testicular germ line cell identification, isolation, and transplantation in two North American catfish species

Our aim was to transplant blue catfish germ line stem cells into blastulae of triploid channel catfish embryos to produce interspecific xenogenic catfish. The morphological structure of the gonads of blue catfish (Ictalurus furcatus) in ~ 90- to 100-day-old juveniles, two-year-old juveniles, and mature adults was studied histologically. Both oogonia (12-15 μm, diameter with distinct nucleus 7-8 μm diameter) and spermatogonia (12-15 μm, with distinct nucleus 6-7.5 μm diameter) were found in all ages of fish. The percentage of germ line stem cells was higher in younger blue catfish of both sexes. After the testicular tissue was trypsinized, a discontinuous density gradient centrifugation was performed using 70, 45, and 35% Percoll to enrich the percentage of spermatogonial stem cells (SSCs). Four distinct cell bands were generated after the centrifugation. It was estimated that 50% of the total cells in the top band were type A spermatogonia (diameter 12-15 μm) and type B spermatogonia (diameter 10-11 μm). Germ cells were confirmed with expression of vasa. Blastula-stage embryos of channel catfish (I. punctatus) were injected with freshly dissociated blue catfish testicular germ cells as donor cells for transplantation. Seventeen days after the transplantation, 33.3% of the triploid channel catfish fry were determined to be xenogenic catfish. This transplantation technique was efficient, and these xenogenic channel catfish need to be grown to maturity to verify their reproductive capacity and to verify that for the first time SSCs injected into blastulae were able to migrate to the genital ridge and colonize. These results open the possibility of artificially producing xenogenic channel catfish males that can produce blue catfish sperm and mate with normal channel catfish females naturally. The progeny would be all C × B hybrid catfish, and the efficiency of hybrid catfish production could be improved tremendously in the catfish industry.

Improving preimplantation genetic diagnosis (PGD) reliability by selection of sperm donor with the most informative haplotype

BACKGROUND

The study is aimed to describe a novel strategy that increases the accuracy and reliability of PGD in patients using sperm donation by pre-selecting the donor whose haplotype does not overlap the carrier's one.

METHODS

A panel of 4-9 informative polymorphic markers, flanking the mutation in carriers of autosomal dominant/X-linked disorders, was tested in DNA of sperm donors before PGD. Whenever the lengths of donors' repeats overlapped those of the women, additional donors' DNA samples were analyzed. The donor that demonstrated the minimal overlapping with the patient was selected for IVF.

RESULTS

In 8 out of 17 carriers the markers of the initially chosen donors overlapped the patients' alleles and 2-8 additional sperm donors for each patient were haplotyped. The selection of additional sperm donors increased the number of informative markers and reduced misdiagnosis risk from 6.00% ± 7.48 to 0.48% ±0.68. The PGD results were confirmed and no misdiagnosis was detected.

CONCLUSIONS

Our study demonstrates that pre-selecting a sperm donor whose haplotype has minimal overlapping with the female's haplotype, is critical for reducing the misdiagnosis risk and ensuring a reliable PGD. This strategy may contribute to prevent the transmission of affected IVF-PGD embryos using a simple and economical procedure.

TRIAL REGISTRATION

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. DNA testing of donors was approved by the institutional Helsinki committee (registration number 319-08TLV, 2008). The present study was approved by the institutional Helsinki committee (registration number 0385-13TLV, 2013).

Experiences of Family Relationships Among Donor-Conceived Families: A Meta-Ethnography

In this qualitative evidence synthesis, we explore how family relationships are experienced by parents who used gamete donation to conceive. We systematically searched four databases (PubMed, Web of Science, PsycINFO, and ProQuest) for literature related to this topic and retrieved 25 studies. Through the analysis of the qualitative studies, a comprehensive synthesis and framework was constructed. Following the meta-ethnography approach of Noblit and Hare, four main themes were identified: (a) balancing the importance of genetic and social ties, (b) normalizing and legitimizing the family, (c) building strong family ties, and (d) minimizing the role of the donor. Underlying these four main themes, a sense of being "different" and "similar" at the same time was apparent. Findings are discussed in terms of their implications for studying and counseling donor-conceived families.

A rapid and effective nonsurgical artificial insemination protocol using the NSET™ device for sperm transfer in mice without anesthesia

Artificial insemination (AI) is an assisted reproductive technique that is implemented successfully in humans as a fertility treatment, performed extensively for commercial breeding of livestock, and is also successful in laboratory rodents. AI in the mouse may be especially useful for breeding of transgenic or mutant mice with fertility problems, expansion of mouse colonies, and as an alternative to in vitro fertilization. Nonsurgical AI techniques for the mouse have been described previously but are not often implemented due to technical difficulties. Here we compare various protocols for preparation of CD1 recipients prior to AI for naïve (in estrus), ovulation-induced, and superovulated females. Timing of hormone administration relative to sperm delivery is also compared. An improved protocol for nonsurgical AI in mice is described, which incorporates a convenient hormone administration schedule for female recipients and rapid, non-stressful sperm transfer without the need for anesthesia or analgesia.

Surrogate production of eggs and sperm by intrapapillary transplantation of germ cells in cytoablated adult fish

Germ cell transplantation (GCT) is a promising assisted reproductive technology for the conservation and propagation of endangered and valuable genetic resources. In teleost fish, GCT in adult gonads has been achieved only in male recipients, limiting greatly the usefulness of this technique in situations where both sexes need equal and timely attention for conservation and/or propagation. Here we describe a simplified GCT approach that ultimately leads to production of donor-derived eggs and sperm in considerably short time. Donor germ cells isolated from young pejerrey Odontesthes bonariensis (Atherinopsidae) were transplanted non-surgically through the genital papilla into the sexually mature gonads of Patagonian pejerrey O. hatcheri recipients whose gonads have been depleted of endogenous GCs by heat (26°C) and chemical treatment (four doses of Busulfan at 30 mg/kg and 40 mg/kg for females and males, respectively). Transplanted spermatogonial and oogonial cells were able to recolonize the recipients' gonads and produce functional donor origin eggs and sperm within 7 months from the GCT. We confirmed the presence of donor-derived gametes by PCR in 17% and 5% of the surrogate O. hatcheri fathers and mothers, respectively. The crosses between surrogate fathers and O. bonariensis mothers yielded 12.6-39.7% pure O. bonariensis and that between a surrogate mother and an O. bonariensis father yielded 52.2% pure O. bonariensis offspring. Our findings confirm that transplantation of germ cells into sexually competent adult fish by non-surgical methods allows the production of functional donor-derived eggs and sperm in a considerably short time. The methods described here could play a vital role in conservation and rapid propagation of endangered fish genetic resources.

Derivation of sperm from xenografted testis cells and tissues of the peccary (Tayassu tajacu)

Because the collared peccary (Tayassu tajacu) has a peculiar Leydig cell cytoarchitecture, this species represents a unique mammalian model for investigating testis function. Taking advantage of the well-established and very useful testis xenograft technique, in the present study, testis tissue and testis cell suspensions from immature collared peccaries (n=4; 3 months old) were xenografted in SCID mice (n=48) and evaluated at 2, 4, 6, and 8 months after grafting. Complete spermatogenesis was observed at 6 and 8 months after testis tissue xenografting. However, probably due to de novo testis morphogenesis and low androgen secretion, functionally evaluated by the seminal vesicle weight, a delay in spermatogenesis progression was observed in the testis cell suspension xenografts, with the production of fertile sperm only at 8 months after grafting. Importantly, demonstrating that the peculiar testicular cytoarchitecture of the collared peccary is intrinsically programmed, the unique Leydig cell arrangement observed in this species was re-established after de novo testis morphogenesis. The sperm collected from the xenografts resulted in diploid embryos that expressed the paternally imprinted gene NNAT after ICSI. The present study is the first to demonstrate complete spermatogenesis with the production of fertile sperm from testis cell suspension xenografts in a wild mammalian species. Therefore, due to its unique testicular cytoarchitecture, xenograft techniques, particularly testis cell suspensions, may represent a new and very promising approach to evaluate testis morphogenesis and to investigate spermatogonial stem cell physiology and niche in the collared peccary.

Generation of live piglets for the first time using sperm retrieved from immature testicular tissue cryopreserved and grafted into nude mice

Cryopreservation of immature testicular tissues is essential for increasing the possibilities of offspring generation by testicular xenografting for agricultural or medical purposes. However, successful production of offspring from the sperm involved has never been reported previously. In the present study, therefore, using intracytoplasmic sperm injection (ICSI), we examined whether xenogeneic sperm obtained from immature pig testicular tissue after cryopreservation would have the capacity to produce live piglets. Testicular fragments from 9- to 11-day-old piglets were vitrified after 10- or 20-min immersion in vitrification solution containing ethylene glycol (EG), polyvinyl pyrrolidone (PVP) and trehalose as cryoprotectants, and then stored in liquid nitrogen for more than 140 days. Thirty nude mice were assigned to each immersion-time group. Testicular fragments were transplanted under the back skin of castrated mice immediately after warming and removal of the cryoprotectants. Blood and testicular grafts were then recovered from the recipient mice on days 60, 120, 180 and 230−350 (day 0 =  grafting). Histological assessment of the testicular grafts and analyses of inhibin and testosterone production revealed no significant differences between the two immersion-time groups, indicating equal growth activity of the cryopreserved tissues. A single sperm obtained from a mouse in each group on day 230−350 was injected into an in vitro-matured porcine oocyte, and then the ICSI oocytes were transferred to the oviducts of estrus-synchronized recipient gilts. One out of 4 gilts that had received oocytes fertilized using sperm from the 10-min immersion group delivered 2 live piglets, and one of another 4 gilts from the 20-min group delivered 4 live piglets. Thus, we have successfully generated porcine offspring utilizing sperm from immature testicular tissues after cryopreservation and transplantation into nude mice. The present model using pigs will be applicable to many large animals, since pigs are phylogenetically distant from the murine recipients.

[Fertility treatment options for discordant couples living with HIV]

BACKGROUND

Serodiscordant couples live with the risk of HIV infection of the negative partner when attempting to become pregnant. Using density gradient centrifugation (DGC), spermatozoa can be separated from other seminal compartments. Isolated spermatozoa do not contain detectable HIV RNA. DGC followed by artificial insemination may significantly reduce the risk of infection. The Hadassah AIDS Center (HAC) has recently initiated a fertility center for serodiscordant couples.

METHODS

Our patient population includes serodiscordant couples in which the male is HIV positive. The male semen is washed using the DGC procedure. Washed semen is tested for HIV by standard PCR methods. Intrauterine insemination (IUI) is attempted using the washed semen.

RESULTS

A total of 55 couples have registered for this procedure. This includes 16 men who have sex with men, 7 who have hemophilia and 8 couples of Ethiopian origin. The average female age is 33 years. Seven (12%) men had inadequate sperm counts and were referred for IVF. Overall, 34 semen samples were tested for HIV. Only one was found to be positive. During the procedure, 22 couples underwent at least one IUI attempt and 16 (72%) females became pregnant, 3 of them after the first IUI attempt. All women tested for HIV after IUI were found to be negative.

CONCLUSIONS

The pregnancy success rate during the first year of operation was 72%, similar to that reported by other centers in Europe. There were no seroconversions of the female partner. Serodiscordant couples living with HIV in Israel today may consider starting a family, while significantly reducing the risk of infecting the negative female partner.

Fresh MESA improved embryo fertilization, cleavage, blastula formation and implantation rates after failed TESA in couples with obstructive azoospermia

PURPOSE

To determine whether our use of fresh MESA cycles improved outcomes in patients with obstructive azoospermia who had failed IVF with TESA.

METHODS

A prospective observational trial of couples undergoing IVF for obstructive azoospermia was performed at an academic IVF center.

RESULTS

When TESA resulted in poor embryo cleavage, implantation and ongoing pregnancy rates, subsequent fresh MESA cycles in these same couples, demonstrated dramatic improvement in cleavage, blastulation, implantation and live birth rates.

CONCLUSIONS

In patients undergoing IVF-TESA-ICSI with obstructive azoospermia resulting in poor cleavage rates, blastulation rates and cycle failure, a repeat cycle with MESA may result in marked improvement in outcome.

Assisted reproductive technology outcomes in azoospermic men: 10 years of experience with surgical sperm retrieval

An azoospermic man suffers from an absence of sperm in the ejaculate and this condition is present in about 10% of infertile men. Obstructive azoospermia (OA) is characterized by an occlusion or partial absence of the reproductive tract with the presence of normal spermatogenesis. On the other hand, non-obstructive azoospermia (NOA) is characterized by impaired spermatogenesis. In these cases, spermatozoa can be obtained by percutaneous epididymal or testicular sperm aspiration (PESA and TESA, respectively) and used for intracytoplasmic injection (ICSI). To compare ICSI outcomes using spermatozoa that were surgically retrieved by PESA and TESA, azoospermic patients were divided into the following categories: (i) TESA-NOA (n = 102), (ii) TESA-OA (n = 103), and (iii) PESA-OA (n = 171). Fertilization, pregnancy, and implantation rates were compared between the groups. We noted a lower normal fertilization rate (p = 0.0017) and a higher abortion rate (p = 0.0387) among men in the TESA group who had OA when compared with men in the PESA group who had OA. On the other hand, a lower normal fertilization rate (p = 0.05) and a lower rate of non-cleaved embryos (p = 0.034) was found in the TESA group of NOA patients as compared to the TESA group of OA patients. No statistically significant differences were detected between the TESA and PESA groups and the OA and NOA groups, respectively. The clinical outcomes of embryos arising from ICSI cycles using spermatozoa harvested via PESA and TESA were similar, regardless of whether the patient had obstructive or non-obstructive azoospermia.

Advances and applications of germ cell transplantation

When male germ line stem cells are transplanted from the testis of a fertile donor animal to the testis of an infertile recipient they can establish donor-derived spermatogenesis in the recipient testis, and the resulting sperm can transmit the genotype of the donor to the offspring of the recipient. Germ cell transplantation provides a bioassay to study the biology of these stem cells, to develop systems for spermatogonial stem cell isolation and culture, to examine defects in spermatogenesis and to correct male infertility. Although most widely studied in rodents, germ cell transplantation has been applied to larger mammals, including primates. A potential clinical application is restoration of fertility in patients that underwent cytotoxic treatments for cancer. As an alternative to transplantation of isolated germ cells to a recipient testis, ectopic grafting of testis tissue from diverse mammalian donor species, including primates, into a mouse host represents a novel possibility to study spermatogenesis, to investigate the effects of toxins or drugs with the potential to enhance or suppress male fertility, and to produce fertile sperm from immature donors. Therefore, transplantation of germ cells or xenografting of testis tissue are uniquely valuable approaches for the study, preservation and manipulation of male fertility in mammalian species.

Cryosurvival and spermatogenesis after allografting prepubertal mouse tissue: comparison of two cryopreservation protocols

Although childhood cancer treatments are yielding higher survival rates, sterility remains one of the major side effects. For prepubertal boys there are currently no options to preserve fertility. Testicular tissue banking together with subsequent grafting may become a possible strategy in the future. In the present study, we compared two cryopreservation protocols using prepubertal murine testicular tissue. Fresh and cryopreserved testicular tissue was grafted subcutaneously on the back of immune-deficient mice for at least 3 months. Prepubertal murine tissue recovered well after cryopreservation with both ethylene glycol (EG) and dimethylsulfoxide (DMSO). While in fresh murine allografts, spermatozoa were observed in 23% of the tubules; in both the DMSO and the EG groups, 32% of the seminiferous tubules contained spermatozoa. However, with DMSO the structure of the seminiferous tubules was better preserved.

Transient transgene transmission to piglets by intrauterine insemination of spermatozoa incubated with DNA fragments

An efficient and low-cost production of transgenic pigs has significant applications to the pig industry and biomedical science. Generation of transgenic pig by sperm-mediated gene transfer (SMGT) was inexpensive and convenient, and reported with high efficiency. To test the method of SMGT in pigs, we employed deep post-cervical intrauterine insemination of incubated spermatozoa in this study. A test of sperm motility of semen from nine Landrace boars after incubation with radioactively labeled DNA construct indicated that DNA uptake of the sperm was highly correlated with sperm motility at the time of collection. DNA concentration of 50 and 300 microg per one billion sperm was incubated with washed high-motility sperm at 17 degrees C for 2 hr. Twenty one hybrid gilts and sows of Meishan crossed with Large White were inseminated with transgene-incubated sperm and produced 156 piglets. Transgene DNA sequences were identified in 31 piglets by PCR amplification of genomic DNA isolated from piglet ears at the age of 3 days. The deep intrauterine insemination had a higher rate of positive transgenic piglets than regular insemination (29.6% of 98 piglets vs. 3.4% of 58 piglets). However, the exogenous transgene DNA was not detected in any piglets at the age of 70-100 days. Therefore, the results further demonstrated that transgene through incubation with spermatozoa was mostly transiently transmitted to the offspring at early growing stage and lost in adulthood, which may result from episomal DNA replications during cell divisions only at the early stage of development.

The surprising kinetics of the T cell response to live antigenic cells

Cooperation between CD4(+) and CD8(+) T cells is required for the proper development of primary effector and memory CD8(+) T cells following immunization with noninflammatory immunogens. In this study, we characterized murine CD4(+) and CD8(+) T cell responses to male-specific minor histocompatibility (HY) Ags following injection of live male cells into females of the same strain. Male cells are rejected 10-12 days after transfer, coinciding with the expansion and effector function of CD8(+) CTLs to two H-2D(b)-restricted epitopes. Although anti-HY CD4(+) T cell responses are readily detectable day 5 posttransfer, CD8(+) responses are undetectable until day 10. The early CD4(+) response is not dependent on direct presentation of Ag by donor male cells, but depends on presentation of the male cells by recipient APC. The CD4(+) T cell response is required for the priming of CD8(+) T cell effector responses and rejection of HY-incompatible cells. Unexpectedly, HY-specific CD4(+) T cells are also capable of efficiently lysing target cells in vivo. The delay in the CD8(+) T cell response can be largely abrogated by depleting T cells from the male inoculum, and donor male CD8(+) T cells in particular suppress host anti-HY CD8(+) responses. These data demonstrate dramatic differences in host T cell responses to noninflammatory Ags compared with responses to pathogens. We explain the delayed CD8(+) response by proposing that there is a balance between cross-presentation of Ag by helper cell-licensed dendritic cells, on the one hand, and veto suppression by live male lymphocytes on the other.

Retrovirus-mediated in vitro gene transfer into chicken male germ line cells

Chicken testicular cells, including spermatogonia, transplanted into the testes of recipient cockerels sterilized by repeated γ-irradiation repopulate the seminiferous epithelium and resume the exogenous spermatogenesis. This procedure could be used to introduce genetic modifications into the male germ line and generate transgenic chickens. In this study, we present a successful retroviral infection of chicken testicular cells and consequent transduction of the retroviral vector into the sperm of recipient cockerels. A vesicular stomatitis virus glycoprotein G-pseudotyped recombinant retroviral vector, carrying the enhanced green fluorescent protein reporter gene was applied to the short-term culture of dispersed testicular cells. The efficiency of infection and the viability of infected cells were analyzed by flow cytometry. No significant CpG methylation was detected in the infected testicular cells, suggesting that epigenetic silencing events do not play a role at this stage of germ line development. After transplantation into sterilized recipient cockerels, these retrovirus-infected testicular cells restored exogenous spermatogenesis within 9 weeks with approximately the same efficiency as non-infected cells. Transduction of the reporter gene encoding the green fluorescent protein was detected in the sperms of recipient cockerels with restored spermatogenesis. Our data demonstrate that, similarly as in mouse and rat, the transplantation of retrovirus-infected spermatogonia provides an efficient system to introduce genes into the chicken male germ line.

Genomic DNA damage in mouse transgenesis

Creating transgenic mammals is currently a very inefficient process. In addition to problems with transgene integration and unpredictable expression patterns of the inserted gene, embryo loss occurs at various developmental stages. In the present study, we demonstrate that this loss is due to chromosomal damage. We examined the integrity of chromosomes in embryos produced by microinjection of pronuclei, intracytoplasmic sperm injection (ICSI), and in vitro fertilization (IVF)-mediated transgenesis, and correlated these findings with the abilities of embryos to develop in vitro and yield transgenic morulas/blastocysts. Chromosomal analysis was performed after microinjection of the pronuclei in zygotes, as well as in parthenogenetic and androgenetic embryos. In all the pronuclei injection groups, significant oocyte arrest and increased incidence of chromosome breaks were observed after both transgenic DNA injection and sham injection. This indicates that the DNA damage is a transgene-independent effect. In ICSI-mediated transgenesis, there was no significant oocyte arrest. The observed chromosomal damage was lower than that after pronuclei microinjection in zygotes and was dependent upon the presence of exogenous DNA. The occurrence of DNA breaks, as measured by comet assay performed on the sperm prior to ICSI, showed that DNA damage was present in the sperm before fertilization. Embryonic development in vitro and transgene expression at the morula/blastocyst stage were higher in ICSI-mediated transgenesis than after microinjection of pronuclei into zygotes. Sperm-mediated gene transfer via IVF did not affect chromosome integrity, allowed good embryo development, but did not yield any transgenic embryos. The present study demonstrates that DNA damage occurs after both the microinjection of pronuclei and ICSI-mediated transgenesis, albeit through different mechanisms.

Successful transplantation of bovine testicular cells to heterologous recipients

While heterologous germ cell transplantation was successful in pigs and goats, autologous transplantation alone has been reported to result in donor-derived spermatogenesis in cattle. The objective of this study was to investigate whether the transplantation of heterologous germ cells could result in colonization of recipient testes in cattle of different breeds. Testicular cells were isolated from 8 Bos taurus donor bull calves and then transferred into 15 Bos indicus-cross bull calves. All animals were prepubertal, donors were aged 5-7 months and recipients 5-11 months, and scrotal circumferences ranged from 15 to 22 cm. Single cell suspensions of donor testicular cells, prepared by enzymatic digestion, were labelled with fluorescent dyes PKH26 or CFDA-SE, before transfer into the rete testis of recipients under ultrasonographic guidance. To assess the longevity of colonization by donor cells, recipients were castrated 2-30 weeks after cell transfer. Donor cells were observed in 15/25 (60%) of the testes that received PKH26-labelled cells, whereas no CFDA-SE-positive cell was identified in any recipients. The maturity of the donors or recipients (measured by scrotal circumference) did not affect colonization potential. In freshly isolated tubules, clumps of PKH26-positive cells were observed, which indicated either cell division or extensive local colonization of specific areas of the tubules. In frozen sections, PKH26-positive cells were identified on the seminiferous tubule basement membrane, which indicated that these cells had successfully migrated from the tubule lumen and were likely to be spermatogonia. We conclude that PKH26 was more suitable for labelling donor testis cells and donor cells can be identified up to 6 months following transfer. These results indicate that allogeneic transplantation of testicular cells can occur between Bos taurus and Bos indicus cattle. Further studies will investigate functionality of transferred testicular cells.

Embryos generated using testicular spermatozoa have higher developmental potential than those obtained using epididymal spermatozoa in men with obstructive azoospermia

OBJECTIVE

To determine whether the injection of testicular spermatozoa results in more viable embryos (higher implantation rate) than injection of epididymal spermatozoa in cases of obstructive azoospermia.

DESIGN

Retrospective analysis of 265 cases of testicular sperm aspiration (TESA) and percutaneous sperm aspiration (PESA), including 185 cases of obstructive azoospermia.

SETTING

Private Infertility clinic.

PATIENT(S)

None, charts review.

INTERVENTION(S)

None, charts review.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate (PR), implantation rate.

RESULT(S)

Although fertilization rates were higher in the PESA group, implantation rates were significantly better in the TESA group. There was also a trend to higher ongoing PR and lower miscarriage rates in TESA cases.

CONCLUSION(S)

In cases of obstructive azoospermia, embryos generated using testicular spermatozoa have higher developmental potential than those obtained using epididymal spermatozoa.

Male germ cell transplantation in livestock

Male germ cell transplantation is a powerful approach to study the control of spermatogenesis with the ultimate goal to enhance or suppress male fertility. In livestock animals, applications can be expanded to provide an alternative method of transgenesis and an alternative means of artificial insemination (AI). The transplantation technique uses testis stem cells, harvested from the donor animal. These donor stem cells are injected into seminiferous tubules, migrate from the lumen to relocate to the basement membrane and, amazingly, they can retain the capability to produce donor sperm in their new host. Adaptation of the mouse technique for livestock is progressing, with gradual gains in efficiency. Germ cell transfer in goats has produced offspring, but not yet in cattle and pigs. In goats and pigs, the applications of germ cell transplantation are mainly in facilitating transgenic animal production. In cattle, successful male germ cell transfer could create an alternative to AI in areas where it is impractical. Large-scale culture of testis stem cells would enhance the use of elite bulls by providing a renewable source of stem cells for transfer. Although still in a developmental state, germ cell transplantation is an emerging technology with the potential to create new opportunities in livestock production.

Depletion of endogenous germ cells in male pigs and goats in preparation for germ cell transplantation

The efficiency of germ cell transplantation, the procedure of transferring germ cells from a donor male into the testes of recipient males, can be greatly increased by reduction of endogenous germ cells in recipient animals. To develop effective methods for suppression of endogenous spermatogenesis in potential pig and goat recipients, we either administered busulfan to pregnant sows or irradiated the testes of immature goats. Piglets from sows treated twice with busulfan (7.5 mg/kg) at days 98 and 108 of gestation showed reduced gonocyte numbers at 2, 4, and 8 weeks of age and reduced initiation of spermatogenesis at 16 weeks of age. For goats, groups of 3 kids at 1, 5, or 9.5 weeks of age received fractionated irradiation of the testes with 3 doses of 2 Gy on 3 consecutive days. At 2 months after irradiation, 5%-10% of seminiferous tubule cross sections contained pachytene spermatocytes, compared with 50%-100% in controls. At 3 months after irradiation, spermatozoa appeared in 20% of tubule cross sections in all treated goats and in 100% of tubules in control goats. By 6 months after irradiation, spermatogenesis had recovered in 60% of tubules in goats treated at 5 or 9.5 weeks of age but in only 29% of tubules after treatment at 1 week of age. Therefore, late gestation in utero treatment of pigs with low doses of busulfan and testicular irradiation of goats at 1 week of age will result in a reduction in the endogenous germ cell population that could facilitate donor cell colonization after germ cell transplantation.

Significant IgG-immunoreactivity of the spermatogonia of the germ cell-depleted testis after busulfan treatment

Busulfan kills spermatogonia with the exception of a few that are attached to the basal membrane of the seminiferous epithelium. In mice, these remaining spermatogonia reacted strongly to a goat anti-mouse IgG antibody. Spermatogonia in untreated testes rarely showed the same reactivity. Testicular IgG levels are normally minimal but increase markedly, 4 weeks after busulfan treatment before peaking at week 6. Laser scanning cytometry analysis of control and busulfan-treated testicular cells showed busulfan treatment increased the frequency of cells that were positive for not only IgG (from 0.67+/-0.29 to 16.5+/-3.8%) but also for alpha6-integrin, beta1-integrin, GFR(-1 and/or Ret. Thus, an enrichment in putative male stem cells correlates with appearance of IgG expression. Confocal microscopy revealed busulfan-treated cells contained both IgG and GFRalpha-1, and that the initial surface IgG became intracellular in the weeks following busulfan treatment. The basement membranes of the seminiferous tubules were compromised by busulfan treatment as the mRNA expression profiles of various adhesion molecules in the basement membranes were altered and electron microscopy revealed severe damage. Serum IgG levels increased in a manner corresponding with the increase in testicular IgG levels. Thus, it appears that in the busulfan-treated testis, small breaches of the blood-testis barrier leak IgG that is then taken up by a significant number of spermatogonia. When the busulfan-resistant germ cells were transferred into recipient germ cell-depleted testes, they settled and repopulated the recipient testes. Thus, the IgG-bearing cells observed after busulfan treatment may be putative spermatogonial stem cells.

Results of assisted reproductive technique in men with cystic fibrosis

BACKGROUND

Sterility in men with cystic fibrosis (CF) raises the question of the use of assisted reproductive techniques (ART). A multidisciplinary network including adult CF centre and reproductive medicine units was set up to answer requests for ART.

METHODS

This retrospective study included 25 men with CF between 1994 and 2004. Clinical status, semen analysis, CF mutations analysis and artificial insemination by donor (AID) or ICSI after surgical retrieval of sperm were monitored.

RESULTS

All CF men had azoospermia. Two chose AID first (one delivery); 23 chose ICSI. Sperm were surgically retrieved in 21 cases, and ICSI was performed in 19. Pregnancies occurred in 12 of these 19 couples (63%) (two ectopic pregnancies, two spontaneous abortions, one termination of pregnancy for polymalformed twins and 11 single deliveries in nine couples). Two couples tried AID after ICSI failed; one had twins. Another adopted a child, and two had a spontaneous pregnancy. After a follow-up of 4.1+/-2.3 years, two patients died, two underwent lung transplantation and 21 remained stable.

CONCLUSION

ART can help men with CF to become a father, but their health status and short survival need careful counselling and multidisciplinary medical care.

Germ cell transplantation in pigs--advances and applications

Transplantation of germ cells from fertile donor mice to the testes of infertile recipient mice results in donor-derived spermatogenesis and transmission of the donor haplotype to offspring of recipient animals. In the pig, germ cells can be transplanted to a recipient testis by ultrasound-guided cannulation of the rete testis with delivery of cells by gravity flow. It is important to note that germ cell transplantation was successful between unrelated, immuno-competent pigs, whereas transplantation in rodents requires syngeneic or immuno-compromised recipients. Efficiency of colonization of the recipient testis by donor-derived germ cells can be improved by pretreatment of the recipient animal to deplete endogenous germ cells. Genetic manipulation of isolated germ line stem cells and subsequent transplantation will result in production of transgenic sperm. Transgenesis through the male germ line has tremendous potential in species like pigs where embryonic stem cell technology is not available and current options to generate transgenic animals are inefficient. Introduction of a genetic change prior to fertilization will circumvent problems associated with manipulation of early embryos and developmental abnormalities associated with somatic cell nuclear transfer and reprogramming. Viral transduction of germ cells prior to transplantation has been used to generate transgenic rodents and has also shown early promising results in pigs. Current research is directed toward improving protocols for isolation and culture of porcine male germ cells to increase efficiency of transgene transmission and to allow for gene targeting prior to germ cell transplantation. It is expected that germ cell transplantation will then provide a viable alternate approach to generate germ line transgenic pigs.

Assisted reproductive technology: 25 years of progress

Great strides have been made in assisted reproductive technology and nearly all forms of subfertility are now amenable to treatment. Constant advances in technology and ethical controversy ensure it has a high public profile. The impact of assisted reproductive technology will be discussed in this article.

Normal birth after transfer of cryopreserved human embryos generated by microinjection of cryopreserved testicular spermatozoa into cryopreserved human oocytes

OBJECTIVE

To report the first birth after transfer of cryopreserved embryos generated by intracytoplasmic sperm injection of cryopreserved testicular spermatozoa into cryopreserved human oocytes.

DESIGN

Case report.

SETTING

Tertiary center for reproductive technology.

PATIENT(S)

A 36-year-old woman with primary infertility of 3 years' duration and a 37-year-old man with congenital bilateral absence of the vas deferens.

INTERVENTION(S)

Cryopreservation of human embryos after oocytes and sperm thawing.

MAIN OUTCOME MEASURE(S)

Live birth.

RESULT(S)

A healthy, normal female infant with a birth weight of 2,950 g was born by cesarean section at 38 weeks' gestation, with normal 6-month follow-up.

CONCLUSION(S)

Embryo cryopreservation can lead to successful results, even with the use of cryopreserved gametes.

Mammalian freeze-dried sperm can maintain their calcium oscillation-inducing ability when microinjected into mouse eggs

Mammalian freeze-dried sperm can maintain their genetic integrity and event support full development to term when microinjected into mature oocytes. However, it is unknown whether freeze-dried sperm can still maintain their calcium oscillation-inducing capability. Here, we microinjected mouse and bovine freeze-dried sperm into mouse MII oocytes and examined their calcium oscillation-inducing ability following intracytoplasmic sperm injection (ICSI). Two pieces of information are revealed. First, nearly all oocytes injected with a freeze-dried mouse sperm head or a bovine sperm showed fertilization-like calcium oscillations, indicating that freeze-drying treatment does not affect the activity of the sperm factor responsible for calcium oscillations. Second, freeze-dried sperm exhibited high resistance to external temperature increase. This is shown by the finding that the freeze-dried sperm can maintain their calcium oscillation-inducing capacity even following exposure to 100 degrees C for 3 h. We therefore conclude that mammalian sperm can maintain their calcium oscillation-inducing capability following freeze-drying, rehydration, and ICSI treatments.

Spermatogenesis in testes of Dazl null mice after transplantation of wild-type germ cells

Dazl knockout male mice are infertile because their germ cells are unable to complete the first meiotic prophase in the first wave of spermatogenesis and thereafter decrease in number due to a block at the A-aligned to A1 transition. The ability of the surviving somatic components of the testes to retain their function in the absence of mature germ cells was tested by injecting marked wild-type germ cell suspensions containing spermatogonial stem cells. Comparison of the frequency and extent of colonization of Dazl knockout testes with that of testes chemically depleted of germ cells showed little if any difference. It was concluded that Dazlko testes seem unimpaired in their ability to support spermatogenesis. Therefore, Dazlko testes provide a useful and reliable recipient in which to evaluate spermatogonial stem cells. The results furthermore demonstrate that the somatic compartment of the testis of these animals retains functionality.

Recovery, survival and functional evaluation by transplantation of frozen-thawed mouse germ cells

BACKGROUND

Establishing a successful method for testicular stem cell transplantation of frozen-thawed testicular cells would be of immense benefit to boys with childhood cancer undergoing a sterilizing treatment. In this study, we evaluated different cryopreservation protocols in a mouse model by means of testicular germ cell transplantation (TGCT), in order to establish an optimal freezing protocol.

METHODS AND RESULTS

In a first series of experiments, we compared an uncontrolled protocol with 1.5 mol/l dimethyl sulphoxide (DMSO) versus a controlled long protocol (cooling to -80 degrees C) and observed a better viability with the latter protocol (36% versus 48%, P < 0.05). We then compared survival after two thawing methods (37 degrees C water versus ice water) in either a DMSO- or an ethylene glycol (EG)-based protocol, and found no difference. In order to evaluate the functional capacity of the cryopreserved testicular suspension, TGCT was performed with both fresh and frozen-thawed suspensions. In 90% of the successfully injected testes, spermatogenesis was reinitiated using fresh suspensions. In contrast, this figure was only 12.5 and 22.7% after cryopreservation, for the short controlled EG protocol and the uncontrolled DMSO protocol, respectively.

CONCLUSION

Reinitiation of spermatogenesis is possible after cryopreservation of testicular germ cell suspensions. Although cell survival was acceptable, our results after TGCT show that our protocols need further improvement.

Implications of systemic malignancies on human fertility

Cancer patients have now longer life expectancy due to improved treatment modalities. As the mortality rate decreased and the survival rate increased, the consequences of cancer treatment in terms of impaired fertility became more frequently encountered. The objective of this review is to highlight fertility issues associated with systemic malignancies. Systemic malignancies lead to deterioration of human fertility directly or indirectly as a result of cytotoxic treatment regimens. A variety of measures may be used to decrease the incidence of fertility decline that occurs. Gamete cryopreservation represents a widely accepted method for fertility preservation in cancer patients. In addition, other procedures such as germ cell transplantation and ovarian cryopreservation, which are currently being developed, are expected to make significant contribution in these cases. However, there are some ethical issues that should be considered before offering patients any of these options.

[Obstructive azoospermia in men who wish to father children; initial clinical results of intracytoplasmatic sperm injection (ICSI) with surgically retrieved epididymal semen]

OBJECTIVE

To evaluate the results of intracytoplasmatic sperm injection (ICSI) with surgically retrieved epididymal semen.

DESIGN

Prospective, descriptive.

METHODS

Patients with an obstructive azoospermia confirmed by cytological examination of a testis biopsy, and conforming to the regular IVF/ICSI criteria as laid down in 2001 at the University Medical Centre St Radboud Nijmegen, the Netherlands, were included for percutaneous epididymal sperm aspiration (PESA) and ICSI. The main outcome measure was the ongoing pregnancy rate per initiated cycle.

RESULTS

A total of 44 cycles were started in 31 couples. In 43 cases (98%) an ovum pick-up was performed and 41 (93%) embryo transfers were carried out. In 19 (43%) cases, treatment resulted in a positive pregnancy test and 15 (34%) ongoing pregnancies were recorded. In total, 17 healthy children were born (11 boys and 6 girls).

CONCLUSION

ICSI with surgically retrieved semen was successfully used as a treatment for childlessness caused by obstructive azoospermia.

Commitment of fetal male germ cells to spermatogonial stem cells during mouse embryonic development

The continuous production of mammalian sperm is maintained by the proliferation and differentiation of spermatogonial stem cells that originate from primordial germ cells (PGCs) in the early embryo. Although spermatogonial stem cells arise from PGCs, it is not clear whether fetal male germ cells function as spermatogonial stem cells able to produce functional sperm. In the present study, we examined the timing and mechanisms of the commitment of fetal germ cells to differentiate into spermatogonial stem cells by transplantation techniques. Transplantation of fetal germ cells into the seminiferous tubules of adult testis showed that donor germ cells, at 14.5 days postcoitum (dpc), were able to initiate spermatogenesis in the adult recipient seminiferous tubules, whereas no germ cell differentiation was observed in the transplantation of 12.5-dpc germ cells. These results indicate that the commitment of fetal germ cells to differentiate into spermatogonial stem cells initiates between embryonic days 12.5 and 14.5. Furthermore, the results suggest the importance of the interaction between germ cells and somatic cells in the determination of fetal germ cell differentiation into spermatogonial stem cells, as normal spermatogenesis was observed when a 12.5-dpc whole gonad was transplanted into adult recipient testis. In addition, sperm obtained from the 12.5- dpc male gonadal explant had the ability to develop normally if injected into the cytoplasm of oocytes, indicating that normal development of fetal germ cells in fetal gonadal explant occurred in the adult testicular environment.

Fertility and germline transmission of donor haplotype following germ cell transplantation in immunocompetent goats

Transplantation of spermatogonial stem cells into syngeneic or immunosuppressed recipient mice or rats can result in donor-derived spermatogenesis and fertility. Recently, this approach has been employed to introduce a transgene into the male germline. Germ-cell transplantation in species other than laboratory rodents, if successful, holds great promise as an alternative to the inefficient methods currently available to generate transgenic farm animals that can produce therapeutic proteins in their milk or provide organs for transplantation to humans. To explore whether germ-cell transplantation could result in donor-derived spermatogenesis and fertility in immunocompetent recipient goats, testis cells were transplanted from transgenic donor goats carrying a human alpha-1 antitrypsin expression construct to the testes of sexually immature wild-type recipient goats. After puberty, sperm carrying the donor-derived transgene were detected in the ejaculates of two out of five recipients. Mating of one recipient resulted in 15 offspring, one of which was transgenic for the donor-derived transgene. This is the first report of donor cell-derived sperm production and transmission of the donor haplotype to the next generation after germ-cell transplantation in a nonrodent species. Furthermore, these results indicate that successful germ-cell transplantation is feasible between immunocompetent, unrelated animals. In the future, transplantation of genetically modified germ cells may provide a more efficient alternative for production of transgenic domestic animals.