P–078 Prognostic factors for male fertility recovery after microsurgical varicocelectomy

Study question What clinical and laboratory parameters are reliable predictors of spontaneous pregnancy (SP) after microsurgical varicocelectomy in men from infertile couples? Summary answer Predictors of SP after microsurgical varicocele repair are the male age, baseline total sperm motility, and postoperative increase level of TPMSC. What is known already Varicocele is the most common correctable cause of male subfertility. According to the recent meta-analyses and studies, microsurgical varicocelectomy is the “golden standard” method for varicocele repair. However, it is still unclear why at least one-third of subfertile men do not experience improvement in semen parameters and more than half of them do not report fertility recovery after varicocelectomy. There is no consensus so far on the factors affecting the efficacy of varicocele repair in men from infertile couples. Study design, size, duration This retrospective study comprises 93 men from infertile couples, with palpable varicocele, astheno-/oligozoospermia, and who underwent microsurgical subinguinal or inguinal varicocelectomy from September 2015 to May 2019. Participants/materials, setting, methods The changes in semen analysis were assessed (in 3–6 months after surgery) according to WHO–2010, spontaneous pregnancy (SP) rates after surgery also were considered. A stepwise discriminant analysis was performed to identify predictors of SP after varicocelectomy. An increase in TPMSC by at least 12.5 million was defined as a significant effect (SE) of varicocelectomy (reference values for the total number and progressive sperm motility according to WHO–2010: 39 million x 0.32 (32%) progressively motile). Main results and the role of chance Almost all semen parameters (except for semen volume) changed positively after surgery. Sperm concentration increased from 62 mln/ml (17–107) to 85 mln/ml (39–134) p < 0.001, TPMSC increased by an average of 27 mln (2.8 times; p < 0.001). SE was observed in 52% of cases (n = 48), a slight favorable effect in 21% (n = 20), and no effect in 27% (n = 25). 29 patients (31%) reported SP within a year after varicocele repair. 83% of patients (24 from 29) who reported pregnancy after varicocelectomy showed SE. According to the stepwise discriminant analysis, significant predictors of pregnancy after varicocelectomy were the male age (coefficient of the canonical discriminant function = –0.16), the initial total sperm motility (0.02), and the postoperative increase of TPMSC (0.01). Wilks’ lambda was 0.67 and canonical correlation 0.57. The predictive ability of the prognostic model (discriminant function) with these three predictors was 84%, specificity 87%, and sensitivity 76%. The function real predictive accuracy for SP was 70% (21 correct out of 30 predicted). Limitations, reasons for caution The small sample size and the inability to obtain accurate data on the health condition of female partners were the main limitations of the study. Nevertheless, the findings are statistically significant, which suggests that they can be extrapolated to the general sample of subfertile men with clinical varicocele. Wider implications of the findings: The proposed algorithm (function) for the prediction of SP showed satisfied predictive accuracy, and after its external validation can be recommended in 3–6 months after varicocele repair to decide whether it is advisable to expect an SP within a year or to include an infertile couple in ART programs immediately. Trial registration number Not applicable

Extracellular Vesicles Derived from Mesenchymal Stem Cells Recover Fertility of Premature Ovarian Insufficiency Mice and the Effects on their Offspring

It has been reported that extracellular vesicles (EVs) derived from human umbilical cord mesenchymal stem cells (HUCMSCs) can promote the proliferative and secretive functions of granulosa cells. In vivo study further demonstrated that EVs derived from HUCMSCs can not only promote the angiogenesis of ovarian tissue but also restore the function of an ovary of chemically induced premature ovarian insufficiency (POI) mice. However, no study investigates the effects of HUCMSCs derived EVs on fertility recovery of POI mice and evaluating their offspring. This study investigates the effects of HUCMSCs derived EVs on fertility recovery and the cognitive function of their offspring. A POI model was established by intraperitoneal injection of cyclophosphamide (CTX) and busulfan (BUS), and randomly divided into EVs-transplantation group (a single injection of 150 µg EVs proteins which suspended in 0.1 ml phosphate buffer saline [PBS] via tail vein), POI group (a single injection of 0.1 ml PBS via tail vein), and normal control group (a single injection of 0.1 ml PBS via tail vein without intraperitoneal injection of CTX and BUS). After EVs treatment, not only the ovarian function of POI mice recovered but also the fertility increased with less time to get pregnant, evaluating by in vitro fertilization and mating test. Cognitive behaviors of the offspring were similar among the three groups through the Y-maze test and novel object recognition task. An anti-apoptotic effect was identified through immunohistochemistry, real-time polymerase chain reaction and western blot. These findings indicate that HUCMSCs derived EVs can improve the fertility of POI mice without adverse effects on the cognitive behavior of their offspring, highlighting the potential value of EVs to be a cell-free therapy for patients suffering from POI.

Herbicide-tolerant endophytic bacteria of rice plants as the biopriming agents for fertility recovery and disease suppression of unhealthy rice seeds

Background Dirty panicle disease (DPD) caused by several fungal phytopathogens results in damage and depreciation of rice seeds. Unhealthy rice seeds with DPD are potent reservoirs of pathogens and unable to be used as seed stock as they can spread the disease in the paddy fields leading to the severe loss of rice yield and quality. In this study, we aim to search for beneficial endophytes of commercially cultivated rice plants and utilize them as biostimulants in seed biopriming for fertility recovery and disease suppression of unhealthy rice seeds. Results Forty-three bacterial endophytes were isolated from rice plants grown in the herbicide-treated paddy fields. Five isolates of these endophytes belonging to the genus Bacillus show excellent antifungal activity against fungal pathogens of DPD. Based on germination tests, biopriming unhealthy rice seeds by soaking in bacterial suspensions for 9 or 12 h was optimal as evidenced by the lowest disease incidence and longer shoot and root lengths of seedlings germinated, compared with controls made of non-treated or hydroprimed healthy and unhealthy seeds. Pot experiments were carried out to evaluate the impact of seed biopriming, in which the percentage of healthy rice yield produced by rice plants emerging from bioprimed seeds was not significantly different, compared to the controls originating respectively from non-treated healthy seeds and chemical fungicide-treated unhealthy seeds. Conclusion Biopriming of unhealthy rice seeds with herbicide-tolerant endophytic bacteria could recover seed fertility and protect the full life cycle of emerging rice plants from fungal pests. With our findings, seed biopriming is a straightforward approach that farmers can apply to recover unhealthy rice seed stock, which enables them to reduce the cost and use of agrochemicals in the commercial production of rice and to promote green technology in sustainable agriculture.

Spontaneous whole-genome duplication restores fertility in interspecific hybrids

Interspecies hybrids often show some advantages over parents but also frequently suffer from reduced fertility, which can sometimes be overcome through sexual reproduction that sorts out genetic incompatibilities. Sex is however inefficient due to the low viability or fertility of hybrid offspring and thus limits their evolutionary potential. Mitotic cell division could be an alternative to fertility recovery in species such as fungi that can also propagate asexually. Here, to test this, we evolve in parallel and under relaxed selection more than 600 diploid yeast inter-specific hybrids that span from 100,000 to 15 M years of divergence. We find that hybrids can recover fertility spontaneously and rapidly through whole-genome duplication. These events occur in both hybrids between young and well-established species. Our results show that the instability of ploidy in hybrid is an accessible path to spontaneous fertility recovery.

Spontaneous whole-genome duplication restores fertility in interspecific hybrids

Interspecies hybrids often show advantages over parents but suffer from reduced fertility, which can sometimes be overcome through sexual reproduction that sorts out incompatibilities. Sex is however inefficient due to the low viability or fertility of hybrid offspring and thus limits their evolutionary potential. Mitotic cell division could be an alternative to fertility recovery in facultative sexual species. To test this, we evolved under relaxed selection more than 600 diploid yeast hybrids between species that span 100,000 to 15 M years of divergence. We find that hybrids can recover fertility spontaneously and rapidly through whole-genome duplication. These events occurred in both hybrids between young and well-established species. Our results show that the instability of hybrid ploidy is a spontaneous path to fertility recovery.One Sentence SummaryPloidy changes potentiate hybrid speciation by leading to fertility recovery.