Relationship between Semenogelins bound to human sperm and other semen parameters and pregnancy outcomes

Background

Semenogelins (SEMGs) are major components of human seminal vesicle secretions. Due to SEMG’s sperm-motility inhibitor, a significant negative correlation between sperm motility and the proportion of SEMG-bound spermatozoa (SEMG+) was found in asthenozoospermic patients. SEMGs also show intrinsic inhibitory capability for sperm capacitation; however, studies on actual clinical specimens have not been conducted.

Methods

To reveal the relationship between SEMGs and the fertilizing capacity of sperm from male infertile patients who are not restricted to asthenozoospermia, we measured the proportion of SEMG+ in the spermatozoa of 142 male infertile patients. The pregnancy outcomes in partners of these patients were retrospectively analyzed using questionnaires.

Results

Among examined semen parameters, only the total SEMG-unbound sperm count showed a tendency to be different between the spontaneous pregnancy or intra-uterine-insemination-pregnancy groups and in-vitro-fertilization- or intracytoplasmic-sperm-injection-pregnancy groups. It was elevated in the former group, which includes patients who used in vivo fertilization.

Conclusions

The total SEMG-unbound sperm count would be a relevant parameter for in vivo fertilization. This result suggests that SEMGs inhibit ectopic capacitation before sperm reach the fertilization site and that the number of total SEMG-unbound sperm is a parameter directly linked to the possibility of in vivo fertilization.

     

Intra-specific variation of sperm length in the malaria vector <Emphasis Type="Italic">Anopheles gambiae</Emphasis>: males with shorter sperm have higher reproductive success

Background

Intra-specific variation in sperm length influences male reproductive success in several species of insects. In males of the malaria vector Anopheles gambiae, sperm length is highly variable but the significance of this variation is unknown. Understanding what determines the reproductive success of male mosquitoes is critical for controlling malaria, and in particular for replacing natural populations with transgenic, malaria-resistant mosquitoes.

Methods

A laboratory population of A. gambiae males was tested for intra-specific variation in sperm length. A full-sib quantitative genetic design was used to test for a genetic component of sperm length in A. gambiae males and estimate its heritability. This study also tested for a relationship between sperm length and male reproductive success in A. gambiae. Male reproductive success was measured as the proportions of inseminated and ovipositing females.

Results

There was intra-specific variation of sperm length in A. gambiae. There was no significant genetic variation in sperm length and its heritability was low (h² = 0.18) compared to other insects. Sperm length was correlated with male body size (measured as wing length). Males with short sperm had significantly higher reproductive success than males with long sperm and this was independent of body size.

Conclusion

This is the first study to demonstrate intra-specific variation in sperm length in A. gambiae and that males with short sperm have higher reproductive success. That sperm length influences female oviposition is important for any strategy considering the release of transgenic males.

     

Variations in the breeding behavior of cichlids and the evolution of the multi-functional seminal plasma protein,seminal plasma glycoprotein 120

Background

Seminal plasma proteins are associated with successful fertilization. However, their evolutionary correlation with fertilization mechanisms remains unclear. Cichlids from Lake Tanganyika show a variety-rich spawning behavior that is associated with the transfer of the sperm to the egg for fertilization. One of these behaviors, called “oral fertilization,” emerged during their speciation. In oral fertilization, females nuzzle the milt from male genitalia and pick up the released eggs in their mouths, which are then fertilized inside the oral cavity. Thus, the success of the fertilization is dependent on the retention of sperm in the oral cavity during spawning. Sperm aggregation and immobilization in viscous seminal plasma may help retain the sperm inside the oral cavity, which ultimately determines the success of the fertilization. Seminal plasma glycoprotein 120 (SPP120) is one of the major seminal plasma proteins present in cichlids. SPP120 has been implicated to immobilize sperm and increase the milt viscosity. However, the functional linkage between oral fertilization and seminal plasma proteins has not been investigated.

Results

During trials of simulated oral fertilization, it was observed that milt viscosity contributed to fertilization success by facilitating longer retention of the milt inside the mouth during spawning. Glycosylation of SPP120 was associated with high milt viscosity. Its glycosylation was specifically present in the milt of cichlid species exhibiting oral fertilization. Moreover, recombinant SPP120 from several the oral fertilization species strongly immobilized/aggregated sperm. Therefore, the functions of SPP120 (immobilization/aggregation and its glycosylation) may contribute to success of oral fertilization, and these functions of SPP120 are more prominent in oral fertilization species. In addition, comparative phylogenetic analyses showed a positive evolutionary correlation between SPP120 function and oral fertilization. Hence, these evolutions may have occurred to keep up with the transition in the mode of fertilization. In addition, rapid evolution in the molecular sequence might be associated with functional modifications of SPP120.

Conclusion

These results suggest that SPP120 might be associated with oral fertilization. In other words, reproductive traits that define the interaction between sperms and eggs could be the evolutionary selective force that cause the rapid functional modification of the fertilization-related reproductive protein, SPP120.

     

iTRAQ-based analysis of sperm proteome from normozoospermic men achieving the rescue-ICSI pregnancy after the IVF failure

Background

In the assisted reproduction, the infertile molecules of spermatozoa from normozoospermic men who underwent the unexplained failure of in vitro fertilization (IVF) due to the lack of sperm binding to the normal zona pellucida, and then achieved pregnancy with the rescue intracytoplasmic sperm injection (R-ICSI) remain unclear. More works are still necessary to explore this male infertile mechanism.

Methods

Normozoospermicmen with the IVF pregnancy and normozoospermic men with the R-ICSI pregnancy after the conventional IVF failure were collected. iTRAQ-based proteomic approach were performed to reveal the new infertile causes between the IVF pregnancy men and the R-ICSI pregnancy men. To validate the confidence of proteome data, the individual samples were analyzed by western blot and immunofluorescence. Further, the spontaneous acrosome reactions were measured to evaluate the sperm quality.

Results

Compared with IVF pregnancy group, 56 sperm proteins were differentially expressed in the R-ICSI pregnancy group. Bioinformatic analyses (PANTHER, DAVID, PubMed and STRING) indicated these altered sperm proteins were involved in various molecular functions: reproduction, chromosome organization, and sperm-oocyte interaction. Moreover, the confidence of proteome data was confirmed by western blot and immunofluorescence using the individual samples, which were consistent with our proteomic data. Additionally, an increased rate of the spontaneous acrosome reaction rate was found in the R-ICSI pregnancy group.

Conclusions

The sealtered sperm proteins and the increased spontaneous acrosome reaction rate might account for this unexplained male infertility in the R-ICSI pregnancy patients. The present proteomic results will throw light on the better understanding of the unexplained infertile mechanisms underlying these normozoospermic man who achieved R-ICSI pregnancy after IVF failure.

     

ICSI diagnostic: a way to prevent total fertilization failure after 4 unsuccessful IUI

Background

The aim of this retrospective study is to investigate the relevance of dividing oocytes and using some for traditional in vitro fertilization (IVF) and others for intracytoplasmic sperm injection (ICSI) as of the first IVF cycle in patients with unexplained infertility who have undergone 4 intrauterine insemination (IUI) cycles which produced no pregnancies.

Methods

This retrospective study includes patients with unexplained infertility who have failed to become pregnant, after 4 IUI, despite normal semen parameters after sperm capacitation. These women were treated in our assisted fertilization program from 2008 until 2015. We analysed the first cycles of women in whom more than 4 oocyte cumulus complexes (OCC) were retrieved and single embryo transfer was performed.

Results

Dividing oocytes between two fertilization techniques reduce the rate of total fertilization failure during the first IVF cycle. No statistical difference were observed for 2 pronuclei (PN) rate between the two techniques. On the other hand, we observed a significantly lower rate of 3 PN, 1 PN, 0 PN with ICSI in comparison with conventional fertilization.

Conclusions

Splitting the oocytes between classical IVF and ICSI increases the chance of embryo transfer on a first IVF cycle after 4 unsuccessful IUI cycles. This half-and-half policy reduces the risk, for the infertile couple, of facing total failure of fertilization and also can provide useful information for the next attempts.

     

Sperm quality and paternal age: effect on blastocyst formation and pregnancy rates

Background

Several studies suggest a decrease in sperm quality in men in the last decades. Therefore, the aim of this work was to assess the influence of male factors (sperm quality and paternal age) on the outcomes of conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

Methods

This retrospective study included all couples who underwent IVF or ICSI at Montpellier University Hospital, France, between 1 January 2010 and 31 December 2015. Exclusion criteria were cycles using surgically retrieved sperm or frozen sperm, with pre-implantation genetic diagnosis or using frozen oocytes. The primary outcomes were the blastulation rate (number of blastocysts obtained at day 5 or day 6/number of embryos in prolonged culture at day 3) and the clinical pregnancy rate. The secondary outcomes were the fertilization and early miscarriage rates.

Results

In total, 859 IVF and 1632 ICSI cycles were included in this study. The fertilization rate after ICSI was affected by oligospermia. Moreover, in ICSI, severe oligospermia (lower than 0.2 million/ml) led to a reduction of the blastulation rate. Reduced rapid progressive motility affected particularly IVF, with a decrease of the fertilization rate and number of embryos at day 2 when progressive motility was lower than 32%.Paternal age also had a negative effect. Although it was difficult to eliminate the bias linked to the woman’s age, pregnancy rate was reduced in IVF and ICSI when the father was older than 51 and the mother older than 37 years.

Conclusions

These results allow adjusting our strategies of fertilization technique and embryo transfer. In the case of severe oligospermia, transfer should be carried out at the cleaved embryo stage (day 2–3) due to the very low blastulation rate. When the man is older than 51 years, couples should be aware of the reduced success rate, especially if the woman is older than 37 years. Finally, promising research avenues should be explored, such as the quantification of free sperm DNA, to optimize the selection of male gametes.

     

The contraceptive efficacy of intravas injection of Vasalgel™ for adult male rhesus monkeys

Background

Options for male contraception are limited. The purpose of this study was to use a nonhuman primate model to evaluate Vasalgel?, a high molecular weight polymer being developed as a contraceptive device for men.

Methods

Sixteen adult male rhesus monkeys received intravas injections of Vasalgel, consisting of 25% styrene maleic acid in dimethyl sulfoxide. After a one-week recovery, males were returned to outdoor group housing, which included at least 3 and up to 9 intact, breeding females with a successful reproductive history.

Results

Treated males have had no conceptions since Vasalgel injections. All males were housed with intact females for at least one breeding season and seven have been almost continually housed with females for 2 years. Complications were minor and included one incident of incorrect placement of Vasalgel into the vas deferens and the development of a sperm granuloma in one animal. Three unilateral vasectomies were performed, one was necessary for incorrect placement of Vasalgel, the other two were elective.

Conclusions

Intravas injection of Vasalgel in sexually mature adult male rhesus monkeys was effective in preventing conception in a free-living, group environment. Complications were few and similar to those associated with traditional vasectomy.

     

Sperm storage and use in polyandrous females of the globally invasive fruitfly, Ceratitis capitata

The medfly, Ceratitis capitata, is an invasive species in which polyandry, associated with sperm precedence, is a common behaviour in the wild. In this species, characterized by internal fertilization, we disclose how the sperm from two males are stored in the female storage organs and how they are used in terms of paternity outcome. The experiments were designed to furnish comparable and unbiased estimates of sperm numbers and progeny in twice-mated females. Results are incorporated in a model through which it is possible to relate the amount of stored sperm with the progeny of twice-mated females. The results show that polyandrous medfly females conserve equal amounts of sperm from the two males to fertilize their eggs. However, we observed a clear advantage of the second male's sperm in siring progeny, which interestingly decreases in favor of the first male as ovipositions progress. The results enable us to exclude differential sperm mortality and suggest that it is the mechanics governing the storage organs which causes the initial, but decreasing second male sperm precedence during the female reproductive life. These outcomes allow us to correlate sperm use in polyandrous females with the mating strategies and invasiveness of this fly.     

Female mate choice in convict cichlids is transitive and consistent with a self-referent directional preference

Introduction

One of the most important decisions that an animal has to make in its life is choosing a mate. Although most studies in sexual selection assume that mate choice is rational, this assumption has not been tested seriously. A crucial component of rationality is that animals exhibit transitive choices: if an individual prefers option A over B, and B over C, then it also prefers A over C.

Results

We assessed transitivity in mate choice: 40 female convict cichlids had to make a series of binary choices between males of varying size. Ninety percent of females showed transitive choices. The mean preference index was significantly higher when a female chose between their most preferred and least preferred male (male 1 vs. male 3) compared to when they chose between males of adjacent ranks (1 vs. 2 or 2 vs. 3). The results are consistent with a simple underlying preference function leading to transitive choice: females preferred males about one third larger than themselves. This rule of thumb correctly predicted which male was preferred in 67% of the cases and the ordering in binary choices in 78% of cases.

Conclusions

This study provides the first evidence for strong stochastic transitivity in a context of mate choice. The females exhibited ordinal preferences and the direction and magnitude of these preferences could be predicted from a simple rule. The females do not necessarily compare two males to choose the best; it is sufficient to use a self-referent evaluation. Such a simple decision rule has important implications for the evolution of the mating strategies and it is consistent with patterns of assortative mating repeatedly observed at population level.

     

Sperm cryopreservation incidence in men with testicular cancer: towards a stabilization in testicular cancer incidence? Results from the CECOS network

Background

Testicular cancer (TC) represents 1% of all new male cancer cases but remains the most frequent cancer in adolescents and young adults in industrialized countries. In this study, we assessed time trends in use of sperm cryopreservation by men with TC from 1990 to 2013 in France.

Methods

We collected data from patients diagnosed with TC who underwent sperm cryopreservation in the French national network of sperm banks. Trends in the incidence of sperm cryopreservation were estimated through two statistical models: the commonly used Poisson regression model and the Verhulst model.

Results

Between 1990 and 2013, the overall incidence of sperm cryopreservation rose from 1.73 to 5.57 per 100,000 person-years. Poisson regression predicted an incidence of 9 per 100,000 [95% CI?=?8.66–9.34] in 2020. However, since 2005, the observed sperm cryopreservation rate seems to be attenuating. The Verhulst model predicted an incidence of 6 per 100,000 after 2020.

Conclusions

Limitations include the impossibility of analyzing age-standardized incidence. Based on the Verhulst model, results suggest that it is still relevant to follow up TC incidence and sperm cryopreservation in order to confirm or refute the potential decrease already observed in this disease.

     

Sexual size dimorphism in anurans: roles of mating system and habitat types

Background

Sexual size dimorphism (SSD) is widespread and variable among animals. Sexual selection, fecundity selection and ecological divergence between males and females are the major evolutionary forces of SSD. However, the influences of mating system and habitat types on SSD have received little attention. Here, using phylogenetic comparative methods, we at first examine the hypotheses to that mating system (intensity of sexual selection) and habitat types affect significantly variation in SSD in anurans (39 species and 18 genera).

Results

Our data set encompass 39 species with female-biased SSD. We provide evidence that the effects of mating system and habitat types on SSD were non-significant across species, also when the analyses were phylogenetically corrected.

Conclusions

Contrast to the hypotheses, our findings suggest that mating system and habitat types do not play an important role in shaping macro-evolutionary patterns of SSD in anurans. Mating system and habitat types cannot explain the variation in SSD when correcting for phylogenetic effects.

     

Predictive value of sperm deoxyribonucleic acid (DNA) fragmentation index in male infertility

Background

Recently, damage to the sperm DNA has been studied as it is associated with reduced fertilization rates, embryo quality, and pregnancy rates, also higher rates of spontaneous miscarriage.

Objective

To develop a diagnostic method in predicting male infertility.

Material and Methods

The design of this study is cross-sectional. Data were retrieved from medical records of Yasmin IVF Clinic Dr. Cipto Mangunkusumo General Hospital and Daya Medika Infertility Clinic from January to December 2015. Subjects were selected by consecutive sampling and divided into two groups: infertile and fertile. Sperm deoxyribonucleic acid fragmentation index (DFI) was determined by sperm chromatin dispersion (SCD) method using Halosperm® Kit.

Results

There were 114 subjects (36 fertile and 78 infertile) selected into this study. We found no significant difference in the age between both of groups. The median value of sperm DFI in infertile group was significantly higher, 29.95 (26.6–34.3)%, compared to 19.90 (15.6–24.4)% of the fertile group, with p?<?0.001. Area Under Curve (AUC) of sperm DFI, 0.862 (95% CI 0.783, 0.941), was higher than concentration (AUC 0.744; 95% CI 0.657, 0.831), motility (AUC 0.668; 95% CI 0.572, 0.765), and morphology (AUC 0.718; 95% CI 0.697, 0.864) of the semen analysis. At the cut-off point of 26.1%, the sperm DFI had sensitivity of 80.8% (95% CI; 70.0, 88.5), specificity of 86.1% (95% CI; 69.7, 94.8), positive predictive value (PPV) of 92.6% (95% CI; 83.0, 97.3), negative predictive value (NPV) of 67.4% (95% CI; 51.9, 80.0), positive likelihood ratio (PLR) of 12.6 (95% CI; 5.4, 29.4), and negative likelihood ratio (NLR) of 0.48 (95% CI 0.31, 0.75). Sperm DFI of ≥26.1% had prevalence ratio of 2.84 (95% CI 1.86, 4.33) for the occurrence of male infertility.

Conclusion

There was significant difference between the median value of sperm DFI of infertile men and fertile men. Compared to semen analysis, sperm DFI at cut-off point of 26.1% has a higher diagnostic value (AUC).

     

Azoospermia in rabbits following an intravas injection of Vasalgel ™

Background

Vasectomy is currently the only long-acting contraceptive option available for men, despite increasing demand and potentially significant positive impacts on human health of additional male contraceptive options. Vasalgel ? is a high molecular weight hydrogel polymer being developed as a non-hormonal long-acting reversible male contraceptive. Vasalgel consists of styrene-alt-maleic acid dissolved in dimethyl sulfoxide, which is distinct from styrene-alt-maleic anhydride materials previously studied.

Methods

The goal of the study was to determine the contraceptive efficacy of two test articles with different levels of styrene maleic acid (100 %, and 80 % acid/20 % anhydride). The test articles were injected bilaterally in the vasa deferentia of mature male rabbits. Post-implantation analyses of semen parameters were completed over a 12 month period and compared to baseline measures of sperm concentration, motility and forward progression.

Results

Both test articles were effective in blocking the passage of spermatozoa through the vasa deferentia in the 12 subjects completing the study. A significant decrease in sperm concentration occurred following implantation of the test material, with no measurable sperm concentration except for a few samples in one animal that were markedly oligospermic. Vasalgel produced a rapid onset of azoospermia, with no sperm in semen samples collected as early as 29–36 days post-implantation, and was durable over a 12 month period.

Conclusion

This study indicated that Vasalgel is an effective non-hormonal long-acting male contraceptive in a rabbit model.

     

Dynamic localization of SPE-9 in sperm: a protein required for sperm-oocyte interactions in <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis>

Background

Fertilization in Caenorhabditis elegans requires functional SPE-9 protein in sperm. SPE-9 is a transmembrane protein with a predicted extracellular domain that contains ten epidermal growth factor (EGF)-like motifs. The presence of these EGF-like motifs suggests that SPE-9 is likely to function in gamete adhesive and/or ligand-receptor interactions.

Results

We obtained specific antisera directed against different regions of SPE-9 in order to determine its subcellular localization. SPE-9 is segregated to spermatids with a pattern that is consistent with localization to the plasma membrane. During spermiogenesis, SPE-9 becomes localized to spiky projections that coalesce to form a pseudopod. This leads to an accumulation of SPE-9 on the pseudopod of mature sperm.

Conclusions

The wild type localization patterns of SPE-9 provide further evidence that like the sperm of other species, C. elegans sperm have molecularly mosaic and dynamic regions. SPE-9 is redistributed by what is likely to be a novel mechanism that is very fast (~5 minutes) and is coincident with dramatic rearrangements in the major sperm protein cytoskeleton. We conclude that SPE-9 ends up in a location on mature sperm where it can function during fertilization and this localization defines the sperm region required for these interactions.

     

Effects of taurine on male reproduction in rats of different ages

Background

It has been demonstrated that taurine is one of the most abundant free amino acids in the male reproductive system, and can be biosynthesized by male reproductive organs. But the effect of taurine on male reproduction is poorly understood.

Methods

Taurine and β-alanine (taurine transport inhibitor) were offered in water to male rats of different ages. The effects of taurine on reproductive hormones, testis marker enzymes, antioxidative ability and sperm quality were investigated.

Results

The levels of T and LH were obviously increased by taurine supplementation in rats of different ages, and the level of E was also significantly elevated in baby rats. The levels of SOD, ACP, SDH and NOS were obviously increased by taurine administration in adult rats, but the levels of AKP, AST, ALT and NO were significantly decreased. The levels of SOD, ACP, LDH, SDH, NOS, NO and GSH were significantly elevated by taurine administration in aged rats, but the levels of AST and ALT were significantly decreased. The motility of spermatozoa was obviously increased by taurine supplement in adult rats. The numbers and motility of spermatozoa, the rate of live spermatozoa were significantly increased by taurine supplement in aged rats.

Conclusions

The present study demonstrated that a taurine supplement could stimulate the secretion of LH and T, increase the levels of testicular marker enzymes, elevate testicular antioxidation and improve sperm quality. The results imply that taurine plays important roles in male reproduction especially in aged animals.

     

Sex-specific differences in fetal and infant growth patterns: a prospective population-based cohort study

Background

The objective of this study was to assess whether sex-specific differences in fetal and infant growth exist.

Methods

This study was embedded in the Generation R Study, a population-based prospective birth cohort. In total, 8556 live singleton births were included. Fetal growth was assessed by ultrasound. During the first trimester, crown-rump-length (CRL) was measured. In the second and third trimester of pregnancy head circumference (HC), abdominal circumference (AC) and femur length (FL) were assessed. Information on infant growth during the first 2 years of life was obtained from Community Health Centers and included HC, body weight and length.

Results

In the first trimester, male CRL was larger than female CRL (0.12 SD [95% CI 0.03,0.22]). From the second trimester onwards, HC and AC were larger in males than in females (0.30 SD [95% CI 0.26,0.34] and 0.09 SD [95% CI 0.05,0.014], respectively). However, FL in males was smaller compared to female fetuses (0.21 SD [95% CI 0.17,0.26]). Repeated measurement analyses showed a different prenatal as well as postnatal HC growth pattern between males and females. A different pattern in body weight was observed with a higher body weight in males until the age of 12 months where after females have a higher body weight.

Conclusions

Sex affects both fetal as well as infant growth. Besides body size, also body proportions differ between males and females with different growth patterns. This sexual dimorphism might arise from differences in fetal programming with sex specific health differences as a consequence in later life.

     

Sperm aneuploidy and DNA fragmentation in unexplained recurrent pregnancy loss: a multicenter case-control study

Background

Recurrent pregnancy loss (RPL) is defined as the loss of at least three pregnancies in the first trimester. Although the most common cause is embryo aneuploidy, and despite female checkup and couple karyotyping, in about 50% of cases RPL remain unexplained. Male implication has little been investigated and results are discordant. In this context, we conducted a multi-center prospective case-control study to investigate male gamete implication in unexplained RPL.

Methods

A total of 33 cases and 27 controls were included from three university hospitals. We investigated environmental and family factors with a detailed questionnaire and andrological examination, sperm characteristics, sperm DNA/chromatin status using the sperm chromatin structure assay (SCSA) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and sperm aneuploidy using fluorescence in situ hybridization (FISH). The Mann-Whitney test and the Wilcoxon or Fisher exact tests were used. A non-parametric Spearman correlation was performed in order to analyze the relationship between various sperm parameters and FISH and sperm DNA fragmentation results.

Results

We found significant differences between cases and controls in time to conceive, body mass index (BMI), family history of infertility and living environment. In cases, total sperm motility and the percentage of morphologically normal spermatozoa were significantly decreased. No difference was found between cases and controls in sperm DNA fragmentation or chromatin integrity. In cases, spermatozoa with aneuploidy, hyperhaploidy and chromosome 18 disomy were significantly increased.

Conclusions

This prospective case-control study is one of the largest to examine environmental factors, sperm characteristics, sperm DNA fragmentation and chromatin, and chromosome anomalies in spermatozoa in relation to unexplained recurrent pregnancy loss. The originality of our study lies in the comprehensive andrological examination and search for risk factors and fertility history. Further studies are needed to confirm the links between unexplained RPL and a male family history of infertility or miscarriages. The increased sperm aneuploidy observed in unexplained RPL supports a male etiology. These data pave the way for further studies to demonstrate the value of preimplantation genetic screening in men with increased sperm aneuploidy whose partners experience unexplained RPL.

     

Management of the infertile couple: an evidence-based protocol

Background

Infertility is defined as inability of a couple to conceive naturally after one year of regular unprotected sexual intercourse. It remains a major clinical and social problem, affecting perhaps one couple in six. Evaluation usually starts after 12 months; however it may be indicated earlier. The most common causes of infertility are: male factor such as sperm abnormalities, female factor such as ovulation dysfunction and tubal pathology, combined male and female factors and unexplained infertility.

Objectives

The aim of this study is to provide the healthcare professionals an evidence-based management protocol for infertile couples away from medical information overload.

Methods

A comprehensive review where the literature was searched for "Management of infertility and/or infertile couples" at library website of University of Bristol (MetaLib) by using a cross-search of different medical databases besides the relevant printed medical journals and periodicals. Guidelines and recommendations were retrieved from the best evidence reviews such as that from the American College of Obstetricians and Gynaecologists (ACOG), American Society for Reproductive Medicine (ASRM), Canadian Fertility and Andrology Society (CFAS), and Royal College of Obstetricians and Gynaecologists (RCOG).

Results

A simple guide for the clinicians to manage the infertile couples.

Conclusions

The study deploys a new strategy to translate the research findings and evidence-base recommendations into a simplified focused guide to be applied on routine daily practice. It is an approach to disseminate the recommended medical care for infertile couple to the practicing clinicians.

     

A novel nucleo-cytoplasmic hybrid clone formed via androgenesis in polyploid gibel carp

Background

Unisexual vertebrates have been demonstrated to reproduce by gynogenesis, hybridogenesis, parthenogenesis, or kleptogenesis, however, it is uncertain how the reproduction mode contributes to the clonal diversity. Recently, polyploid gibel carp has been revealed to possess coexisting dual modes of unisexual gynogenesis and sexual reproduction and to have numerous various clones. Using sexual reproduction mating between clone D female and clone A male and subsequent 7 generation multiplying of unisexual gynogenesis, we have created a novel clone strain with more than several hundred millions of individuals. Here, we attempt to identify genetic background of the novel clone and to explore the significant implication for clonal diversity contribution.

Methods

Several nuclear genome markers and one cytoplasmic marker, the mitochondrial genome sequence, were used to identify the genetic organization of the randomly sampled individuals from different generations of the novel clone.

Results

Chromosome number, Cot-1 repetitive DNA banded karyotype, microsatellite patterns, AFLP profiles and transferrin alleles uniformly indicated that nuclear genome of the novel clone is identical to that of clone A, and significantly different from that of clone D. However, the cytoplasmic marker, its complete mtDNA genome sequence, is same to that of clone D, and different from that of clone A.

Conclusions

The present data indicate that the novel clone is a nucleo-cytoplasmic hybrid between the known clones A and D, because it originates from the offspring of gonochoristic sexual reproduction mating between clone D female and clone A male, and contains an entire nuclear genome from the paternal clone A and a mtDNA genome (cytoplasm) from the maternal clone D. It is suggested to arise via androgenesis by a mechanism of ploidy doubling of clone A sperm in clone D ooplasm through inhibiting the first mitotic division. Significantly, the selected nucleo-cytoplasmic hybrid female still maintains its gynogenetic ability. Based on the present and previous findings, we discuss the association of rapid genetic changes and high genetic diversity with various ploidy levels and multiple reproduction modes in several unisexual and sexual complexes of vertebrates and even other invertebrates.