Biologie de la Reproduction, Environnement, Epigénétique et Développement

BACKGROUND: The fungal genus Aspergillus is of critical importance to humankind. Species include those with industrial applications, important pathogens of humans, animals and crops, a source of potent carcinogenic contaminants of food, and an important genetic model. The genome sequences of eight aspergilli have already been explored to investigate aspects of fungal biology, raising questions about evolution and specialization within this genus. RESULTS: We have generated genome sequences for ten novel, highly diverse Aspergillus species and compared these in detail to sister and more distant genera. Comparative studies of key aspects of fungal biology, including primary and secondary metabolism, stress response, biomass degradation, and signal transduction, revealed both conservation and diversity among the species. Observed genomic differences were validated with experimental studies. This revealed several highlights, such as the potential for sex in asexual species, organic acid production genes being a key feature of black aspergilli, alternative approaches for degrading plant biomass, and indications for the genetic basis of stress response. A genome-wide phylogenetic analysis demonstrated in detail the relationship of the newly genome sequenced species with other aspergilli. CONCLUSIONS: Many aspects of biological differences between fungal species cannot be explained by current knowledge obtained from genome sequences. The comparative genomics and experimental study, presented here, allows for the first time a genus-wide view of the biological diversity of the aspergilli and in many, but not all, cases linked genome differences to phenotype. Insights gained could be exploited for biotechnological and medical applications of fungi.

PURPOSE: Approximately 1% of lung adenocarcinomas are driven by oncogenic ROS1 rearrangement. Crizotinib is a potent inhibitor of both ROS1 and ALK kinase domains. PATIENTS AND METHODS: In the absence of a prospective clinical trial in Europe, we conducted a retrospective study in centers that tested for ROS1 rearrangement. Eligible patients had stage IV lung adenocarcinoma, had ROS1 rearrangement according to fluorescent in situ hybridization, and had received crizotinib therapy through an individual off-label use. Best response was assessed locally using RECIST (version 1.1). All other data were analyzed centrally. RESULTS: We identified 32 eligible patients. One patient was excluded because next-generation sequencing was negative for ROS1 fusion. Median age was 50.5 years, 64.5% of patients were women, and 67.7% were never-smokers. Thirty patients were evaluable for progression-free survival (PFS), and 29 patients were evaluable for best response. We observed four patients with disease progression, two patients with stable disease, and objective response in 24 patients, including five complete responses (overall response rate, 80%; disease control rate, 86.7%). Median PFS was 9.1 months, and the PFS rate at 12 months was 44%. No unexpected adverse effects were observed. Twenty-six patients received pemetrexed (either alone or in combination with platinum and either before or after crizotinib) and had a response rate of 57.7% and a median PFS of 7.2 months. CONCLUSION: Crizotinib was highly active at treating lung cancer in patients with a ROS1 rearrangement, suggesting that patients with lung adenocarcinomas should be tested for ROS1. Prospective clinical trials with crizotinib and other ROS1 inhibitors are ongoing or planned.

Sex differences occur in most non-communicable diseases, including metabolic diseases, hypertension, cardiovascular disease, psychiatric and neurological disorders and cancer. In many cases, the susceptibility to these diseases begins early in development. The observed differences between the sexes may result from genetic and hormonal differences and from differences in responses to and interactions with environmental factors, including infection, diet, drugs and stress. The placenta plays a key role in fetal growth and development and, as such, affects the fetal programming underlying subsequent adult health and accounts, in part for the developmental origin of health and disease (DOHaD). There is accumulating evidence to demonstrate the sex-specific relationships between diverse environmental influences on placental functions and the risk of disease later in life. As one of the few tissues easily collectable in humans, this organ may therefore be seen as an ideal system for studying how male and female placenta sense nutritional and other stresses, such as endocrine disruptors. Sex-specific regulatory pathways controlling sexually dimorphic characteristics in the various organs and the consequences of lifelong differences in sex hormone expression largely account for such responses. However, sex-specific changes in epigenetic marks are generated early after fertilization, thus before adrenal and gonad differentiation in the absence of sex hormones and in response to environmental conditions. Given the abundance of X-linked genes involved in placentogenesis, and the early unequal gene expression by the sex chromosomes between males and females, the role of X- and Y-chromosome-linked genes, and especially those involved in the peculiar placenta-specific epigenetics processes, giving rise to the unusual placenta epigenetic landscapes deserve particular attention. However, even with recent developments in this field, we still know little about the mechanisms underlying the early sex-specific epigenetic marks resulting in sex-biased gene expression of pathways and networks. As a critical messenger between the maternal environment and the fetus, the placenta may play a key role not only in buffering environmental effects transmitted by the mother but also in expressing and modulating effects due to preconceptional exposure of both the mother and the father to stressful conditions.

STUDY QUESTION: Are temporal trends and values of semen quality parameters in France identifiable in partners of totally infertile women? SUMMARY ANSWER: Among a sample of 26 609 partners of totally infertile women undergoing an assisted reproductive technology (ART) procedures in the whole of France over a 17-year period, there was a continuous decrease in semen concentration of about 1.9% per year and a significant decrease in the percentage with morphologically normal forms but no global trend for motility. WHAT IS KNOWN ALREADY: A global decrease in human sperm quality is still debated as geographical differences have been shown, and many criticisms have risen concerning studies with small and biased study populations or inappropriate statistical methodology. However, growing biological, toxicological, experimental and human exposure data support the endocrine disruptors' hypothesis assuming that fetal exposure to endocrine disruptors could impair reproductive outcomes. STUDY DESIGN, SIZE, DURATION: This was a retrospective and descriptive study using data registered by Fivnat, the professional association in charge of statistics for ART in France during the 1989-2005 study period. Data were provided by 126 main ART centres over the whole metropolitan territory. The source population included 154 712 men, aged 18-70, who were partners of couples undergoing their first ART cycle and for whom semen quality indicators (concentration, total motility and percentage of morphologically normal forms), measured on fresh ejaculated semen, were available. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study population was 26 609 partners of women who had both tubes either absent or blocked. The temporal trends for each indicator of semen quality were modelled using a generalized additive model that allowed for nonlinear relationships between variables and were adjusted for season and age. In-depth sensitivity analyses included the reiteration of the analysis on data from a second spermiogram available for each man and on another subsample of men diagnosed as fertile. Variables such as centre, technique (standard in vitro fertilization or intra-cytoplasmic sperm injection) and an interaction factor between technique and time were also included in the model. MAIN RESULTS AND THE ROLE OF CHANCE: There was a significant and continuous decrease in sperm concentration of 32.2% [26.3-36.3] during the study period. Projections indicate that concentration for a 35-year-old man went from an average of 73.6 million/ml [69.0-78.4] in 1989 to 49.9 million/ml [43.5-54.7] in 2005. A significant, but not quantifiable, decrease in the percentage of sperm with morphologically normal forms along the 17-year period was also observed. There was no global trend but a slight, significant increase in total motility between 1994 and 1998 was observed. The results were robust after sensitivity analysis. LIMITATIONS, REASONS FOR CAUTION: Socioeconomic status could not be controlled for. Despite universal access to medical services in France, couples undergoing ART are expected to have a higher educational level on average compared with those of the general population. Therefore, the real values in the general population could be slightly lower than those presented and the decrease possibly stronger, as the population study is less likely to smoke or be overweight, two factors known to impair semen quality. WIDER IMPLICATIONS OF THE FINDINGS: As the men were selected without a priori knowledge regarding their semen quality characteristics, the results are expected to be close to the values in the general French population. The very large sample size and the robustness of the results confer great statistical power and credibility to the results. To our knowledge, it is the first study concluding a severe and general decrease in sperm concentration and morphology at the scale of a whole country over a substantial period. This constitutes a serious public health warning. The link with the environment particularly needs to be determined.

The authors retrospectively analyzed the initial characteristics, treatment, and clinical course in 147 patients with essential thrombocythemia (ET). Median age was 60 years and the M:F ratio was 0.69. At diagnosis, 53 patients were asymptomatic; 50 patients had functional symptoms (mainly vasomotor disturbances); 27 patients had large vessel thrombosis; 27 patients had a bleeding diathesis; and seven patients had both bleeding and thrombosis. The platelet count ranged from 0.7 to 2.92 × 1012/I. Forty-five of the 61 tested patients (61%) had prolonged bleeding time and/or platelet hypoaggregation. Three patients had in vitro spontaneous aggregation. No significant correlations were found between hemostatic findings and in vivo bleeding or thrombosis. The incidence of bleeding, however, was higher in patients with more than 2 × 1012/I platelets. Of 87 karyotypes performed with banding techniques, only four were abnormal. One hundred twenty-nine patients received one or more cytoreductive agents at diagnosis or during follow-up. Sixty patients received an antiaggregating agent. First-line therapy was radiophosphorus (32P) in 22 patients; busulfan in 35 patients; and hydroxyurea in 72 patients. Hydroxyurea required continuous maintenance therapy and had to be changed to another treatment in 12 of the initial responders because of inadequate control of thrombocythemia. During follow-up, 14 treated patients experienced one or several major thrombotic events. Two untreated patients also had major thrombosis. Only one major bleeding event was seen during follow-up. Median actuarial survival was 73.5% at 7 years and only one patient progressed to acute non-lymphocytic leukemia (ANLL). These results suggest that large vessel thrombosis is the main complication of ET. It appears largely unpredictable in a given patient at diagnosis but can be largely prevented by the control of thrombocythemia. Because of the low incidence of side effects of treatment in this experience, the authors believe that cytoreductive therapy is indicated in most patients with ET, as long as a group of patients with very low risk of thrombosis is not defined in prospective studies.

Previous studies have equated FOXL2 as a crucial actor in the ovarian differentiation process in different vertebrate species. Its transcriptional extinction in the polled intersex syndrome (PIS) leads primarily to a drastic decrease of aromatase (CYP19) expression in the first steps of goat ovarian development. In this study, we provide a better characterization of early ovarian development in goat, and we provide experimental evidence demonstrating that FOXL2 represents a direct transcriptional activator of the CYP19 gene through its ovarian-specific promoter 2. Moreover, the ovarian location of FOXL2 and CYP19 proteins, together with their expression profiles in the female gonads, stress the involvement of FOXL2 co-factor(s) for regulating CYP19 transcription. Expressional analyses show that activin-betaA can be considered as a strong candidate for being one of these FOXL2 co-factors. Finally, we discuss evidence for a role of activin and estrogens in somatic and germinal cell proliferation occurring before germ cell meiosis. This period, of 20 days in goat, seems to have no equivalent in mouse. This species-specific difference could explain the phenotype discrepancy observed between XX goat PIS(-/-) and XX mouse Foxl2(-/-).

Semen analysis is the cornerstone of male fertility evaluation with WHO guidelines providing the basis for procedural standardization and reference values worldwide. The first WHO manual was published in 1980, and five editions have been subsequently released over the last four decades. The 6th Edition was published in July 2021. In this review, we identify the key changes of this 6th Edition. Additionally, we evaluate the utility of this 6th Edition in clinical practice using SWOT (strengths, weaknesses, opportunities, and threats) analysis. This new Edition has made the analysis of basic semen parameters more robust, taking into account the criticisms and grey areas of the previous editions. The tests assessing sperm DNA fragmentation and seminal oxidative stress are well-described. The main novelty is that this latest edition abandons the notion of reference thresholds, suggesting instead to replace them with "decision limits". While this seems attractive, no decision limits are proposed for either basic semen parameters, or for extended or advanced parameters. This critical review of the 6th Edition of the WHO laboratory manual combined with a SWOT analysis summarizes the changes and novelties present in this new Edition and provides an in-depth analysis that could help its global use in the coming years.

Abstract Successful pregnancy requires an appropriate communication between the mother and the embryo. Recently, exosomes and microvesicles, both membrane-bound extracellular vesicles (EVs) present in the oviduct fluid have been proposed as key modulators of this unique cross-talk. However, little is known about their content and their role during oviduct-embryo dialog. Given the known differences in secretions by in vivo and in vitro oviduct epithelial cells (OEC), we aimed at deciphering the oviduct EVs protein content from both sources. Moreover, we analyzed their functional effect on embryo development. Our study demonstrated for the first time the substantial differences between in vivo and in vitro oviduct EVs secretion/content. Mass spectrometry analysis identified 319 proteins in EVs, from which 186 were differentially expressed when in vivo and in vitro EVs were compared (P < 0.01). Interestingly, 97 were exclusively expressed in in vivo EVs, 47 were present only in in vitro and 175 were common. Functional analysis revealed key proteins involved in sperm–oocyte binding, fertilization and embryo development, some of them lacking in in vitro EVs. Moreover, we showed that in vitro-produced embryos were able to internalize in vivo EVs during culture with a functional effect in the embryo development. In vivo EVs increased blastocyst rate, extended embryo survival over time and improved embryo quality. Our study provides the first characterization of oviduct EVs, increasing our understanding of the role of oviduct EVs as modulators of gamete/embryo–oviduct interactions. Moreover, our results point them as promising tools to improve embryo development and survival under in vitro conditions.

There has been a growing interest over the past few years in the impact of male nutrition on fertility. Infertility has been linked to male overweight or obesity, and conventional semen parameter values seem to be altered in case of high body mass index (BMI). A few studies assessing the impact of BMI on sperm DNA integrity have been published, but they did not lead to a strong consensus. Our objective was to explore further the relationship between sperm DNA integrity and BMI, through a 3-year multicentre study. Three hundred and thirty male partners in subfertile couples were included. Using the terminal uridine nick-end labelling (TUNEL) assay, we observed an increased rate of sperm DNA damage in obese men (odds ratio (95% confidence interval): 2.5 (1.2-5.1)).

Mutations in the forkhead transcription factor gene FOXL2 are involved in ovarian failure, which occurs in human BPES syndrome. This syndrome presents a sexually dimorphic expression, specific to the ovary in several vertebrates. We cloned the open reading frame of chicken FOXL2 (cFoxL2) and studied cFoxL2 expression in developing gonads and during adulthood to examine the role of FOXL2 in ovarian differentiation and function in birds. The spatial and temporal dynamics of cFoxL2 and aromatase expression were analyzed in parallel by using real-time quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry in attempt to investigate the possible role of cFoxL2 in the regulation of aromatase. The expression patterns of cFoxL2 and aromatase transcripts were highly correlated during the sex-differentiation period (4.7-12.7 days of incubation). Aromatase and cFoxL2 proteins were colocalized in the medullar part of female gonads on embryonic day 14. Fourteen days after hatching, cFoxL2 protein was mainly detected in granulosa cells of developing follicles. In adult ovary follicular envelopes, apart from granulosa cells, cFoxL2 transcript and protein were detected at lower levels in theca cells where aromatase was present. A high level of cFoxL2 transcription was also observed in maturing and ovulated oocytes. Our results confirm that FoxL2 is an early regulator of ovarian development in birds and may be involved in aromatase transcription regulation.

In mammals, X-chromosome dosage compensation is achieved by inactivating one of the two X chromosomes in females. In mice, X inactivation is initially imprinted, with inactivation of the paternal X (Xp) chromosome occurring during preimplantation development. One theory is that the Xp is preinactivated in female embryos, because of its previous silence during meiosis in the male germ line. The extent to which the Xp is active after fertilization and the exact time of onset of X-linked gene silencing have been the subject of debate. We performed a systematic, single-cell transcriptional analysis to examine the activity of the Xp chromosome for a panel of X-linked genes throughout early preimplantation development in the mouse. Rather than being preinactivated, we found the Xp to be fully active at the time of zygotic gene activation, with silencing beginning from the 4-cell stage onward. X-inactivation patterns were, however, surprisingly diverse between genes. Some loci showed early onset (4-8-cell stage) of X inactivation, and some showed extremely late onset (postblastocyst stage), whereas others were never fully inactivated. Thus, we show that silencing of some X-chromosomal regions occurs outside of the usual time window and that escape from X inactivation can be highly lineage specific. These results reveal that imprinted X inactivation in mice is far less concerted than previously thought and highlight the epigenetic diversity underlying the dosage compensation process during early mammalian development.

BACKGROUND: In vitro oocyte maturation (IVM) permits the use of immature oocytes in IVF. IVM does not require ovarian stimulation and so can be offered to patients at risk of ovarian hyperstimulation syndrome. METHODS: For this indication, we carried out 45 cycles of IVM in 33 women with polycystic ovarian syndrome (PCOS). RESULTS: A total of 509 cumulus-oocyte complexes was obtained; 276 (54.2%) oocytes matured in 24 h and 45 (8.8%) in 48 h. The normal fertilization (2PN) rate of oocytes matured in 24 and 48 h was 69.5 and 73.3% respectively. Among the 214 embryos obtained, 103 were transferred and 30 were frozen. Forty transfers were performed (2.5 embryos/transfer). Eleven women had a positive beta-hCG test (26.2% of pregnancies/puncture, 27.5% of pregnancies/transfer) and nine women had a clinical pregnancy (20.0% of pregnancies/puncture, 22.5% of pregnancies/transfer). Five babies have been born and one pregnancy is ongoing. Results of the clinical examination carried out at birth were normal. CONCLUSIONS: Our results show that IVM may be offered as an alternative to conventional IVF and to ovarian drilling in women with PCOS. The role of IVM in the therapeutic armamentarium for this condition should be further clarified.

BACKGROUND: Macrocephalic or large headed sperm with multiflagella is a rare abnormality often associated with infertility. Sperm chromosomal abnormalities could be associated with this specific morphological abnormality. METHODS: The cytogenetic content of large-headed sperm was assessed by dual and three-colour fluorescence in-situ hybridization in three patients carrying this specific morphological abnormality. RESULTS: In all patients nearly all sperm contained at least one copy of each sex chromosome, and in more than half of them at least two copies of either chromosome 1 or 18 were identified. In some sperm a tetraploidy was found. CONCLUSIONS: These observations suggested that both meiotic I and II divisions were affected by incomplete partition of homologous chromosomes during meiosis I and of sister chromatids during meiosis II associated with a failure of nuclear cleavage. Furthermore, they provide evidence for a clear relationship between a specific morphological abnormality of the sperm and their abnormal cytogenetic content. The treatment of infertility using ICSI would probably be unsuccessful and have a high genetic risk in these cases.

I wish to thank the members of the John Hammond Memorial Committee for their kind invitation to deliver this lecture, which expresses very personal feelings. When, in 1949, as a recently graduated Ph.D. from the University of Paris, I was seeking my future orientation in research, I had the good luck to be in Ghent when John Hammond presented a prospective survey of the improvement of fertility in domestic animals by hormonal treatment. Some months later, I visited Hammond's laboratory in Cambridge and studied his books and papers on reproduction in the cow and rabbit. Today, looking back over the past 26 years, I have the feeling that my work as a scientist, and as a Professor, found much of its inspiration in Hammond's thought and teaching.

BACKGROUND: To assess HIV burden in both acellular and cellular fractions of semen in men with different levels of blood plasma HIV RNA by a cross-sectional study. PATIENTS: Fifty-two HIV-1-seropositive men (21 receiving antiretroviral therapy) with CD4 cell counts ranging from 1 to 1170 x 10(6)/l. METHODS: Semen was separated into seminal plasma and fractions enriched in motile spermatozoa or non-spermatozoal cells. HIV RNA was quantified by the HIV-Monitor technique (Roche) in blood plasma, seminal plasma and spermatozoa fractions. HIV DNA or infectious virions in cellular fractions were detected by either PCR or qualitative viral culture. RESULTS: HIV RNA was detected in 86.5% of seminal plasma specimens and in 14.6% of spermatozoa fractions; HIV DNA was detected in 57.1% of non-spermatozoal cell fractions. HIV RNA levels in blood plasma and seminal plasma were correlated (r5 = 0.56, P < 0.0001, Spearman's rank test). A majority of men had lower levels in seminal plasma than in blood plasma: one-third had HIV-positive seminal cell fractions. However, 20 men (38.5%) with HIV RNA levels in seminal plasma (median: 4.65 log10 copies/ml) comparable to or higher than those in blood plasma had all HIV-positive non-spermatozoal cells or spermatozoa fractions with a high frequency of positive cultures. CONCLUSION: A high frequency of men had detectable HIV in semen. We identified a subpopulation demonstrating high levels of HIV RNA in seminal plasma, comparable to or higher than those in blood plasma, frequently associated with a substantial viral shedding in seminal cells, raising the possibility of viral production within the genital tract and suggesting heterogeneity in the potential of HIV sexual transmission among infected men.

Masurel‐Paulet A, Andrieux J, Callier P, Cuisset JM, Le Caignec C, Holder M, Thauvin‐Robinet C, Doray B, Flori E, Alex‐Cordier MP, Beri M, Boute O, Delobel B, Dieux A, Vallee L, Jaillard S, Odent S, Isidor B, Beneteau C, Vigneron J, Bilan F, Gilbert‐Dussardier B, Dubourg C, Labalme A, Gautier A, Pernes P, Bidon C, Pinoit JM, Huet F, Mugneret F, Aral B, Jonveaux P, Sanlaville D, Faivre L. Delineation of 15q13.3 microdeletions. The increasing use of array‐comparative genomic hybridization (array‐CGH) to identify copy number variations (CNVs) in patients with developmental delay (DD), mental retardation and/or dysmorphic features has allowed the recent recognition of numerous genomic imbalances, including the 15q13.3 microdeletion. Patients with this microdeletion generally present with relatively consistent breakpoints at BP4 and BP5, which include the CHRNA7 gene. About 100 index cases have been reported since the first publication in 2008. This large number of patients ascertained through highly variable samples has been necessary to describe the full phenotypic spectrum of this microdeletion, ranging from mental retardation with dysmorphic features, epilepsy, neuropsychiatric disturbances with or without cognitive impairment to complete absence of anomalies. Here, we describe a collaborative study reporting a new cohort of 12 index patients and 13 relatives carrying a heterozygous BP4–BP5 microdeletion out of a series of 4625 patients screened by array‐CGH for DD. We confirm the clinical expressivity of the disease as well as the incomplete penetrance in seven families. We showed through a review of the literature that males are more likely to be symptomatic. Sequence analysis of CHRNA7 yielded no data to support the unmasking of recessive variants as a cause of phenotypic variability. We also report the first patient carrying a 15q13.3 homozygous microdeletion inherited from both parents. He had severe epileptic encephalopathy with retinopathy, autistic features and choreoathetosis. Besides the classical ∼1.5 Mb BP4–BP5 microdeletion, we also describe three index patients and two relatives with a smaller 500 kb microdeletion, including the CHRNA7 gene.

BACKGROUND: Chemerin is a novel adipokine involved in the regulation of adipocyte development, inflammation and metabolic functions. To date, no role of this adipokine in reproductive functions has been described. In the present study, we identified chemerin and its receptor, CMKLR1 (chemokine-like receptor 1), in primary human granulosa cells (hGCs) and in a human ovarian granulosa-like tumour cell line (KGN). We also investigated the effects of recombinant human chemerin (rhChem) on steroid production and on various signalling pathways. METHODS AND RESULTS: By RT-PCR immunoblotting and immunohistochemistry, we showed that chemerin and CMKLR1 are expressed in hGCs and KGN cells. By ELISA, we also found chemerin in human follicular fluid and we observed that in 8 of 10 women the chemerin level was at least 2-fold higher in follicular fluid than in plasma. rhChem (10 or 100 ng/ml) significantly decreased insulin-like growth factor-1 (IGF-1) (10(-8) M)-induced secretion of progesterone and estradiol (as determined by radioimmunoassay) but did not affect basal-or FSH (10(-8) M)-induced steroid secretion in hGCs and KGN cells. In parallel, it also decreased IGF-1-induced p450 aromatase protein levels without affecting the protein levels of other factors involved in steroidogenesis (steroidogenic acute regulatory protein, 3-beta-hydroxysteroid dehydrogenase and p450 side-chain cleavage enzyme) in hGCs cells. All these changes were associated with a decrease in the IGF-1-induced tyrosine phosphorylation of IGF-1 receptor beta subunit and phosphorylation of mitogen-activated protein kinase extracellular signal-regulated kinases 1/2 (MAPK ERK1/2) and Akt. In hGCs and KGN cells, rhChem also decreased IGF-1-induced thymidine incorporation. Finally, we showed that rhChem rapidly activates MAPK ERK1/2, MAPK P38 and Akt phosphorylation and more slowly AMP-activated protein kinase phosphorylation under basal conditions (no IGF-1 or FSH) in primary hGC cells. CONCLUSIONS: Taken together, chemerin and its receptor (CMKLR1) are present and active in hGCs. Chemerin reduces IGF-1-induced steroidogenesis and cell proliferation through a decrease in the activation of IGF-1R signalling pathways in primary hGCs.

BACKGROUND: Pericentric inversions are structural chromosomal abnormalities resulting from two breaks, one on either side of the centromere, within the same chromosome, followed by 180 degrees rotation and reunion of the inverted segment. They can perturb spermatogenesis and lead to the production of unbalanced gametes through the formation of an inversion loop. METHODS: We report here the analysis of the meiotic segregation in spermatozoa from six pericentric inversion carriers by multicolour fluorescence in-situ hybridization (FISH) and review the literature. RESULTS: The frequencies of the non-recombinant products (inversion or normal chromosomes) were 80% for the inv(20), 91.41% for the inv(12), 99.43% for the inv(2), 68.12% for the inv(1), 97% for the inv(8)(p12q21) and 60.94% for the inv(8)(p12q24.1). The meiotic segregation of 20 pericentric inversions (including ours) is now available. The frequency of unbalanced spermatozoa varies from 0 to 37.85%. The probability of a crossover within the inverted segment is affected by the chromosome and region involved, the length of the inverted segment and the location of the breakpoints. CONCLUSIONS: No recombinant chromosomes were produced when the inverted segment involved <30% of the chromosome length (independent of the size of the inverted segment). Between 30 and 50%, few recombinant chromosomes were produced, inducing a slightly increased risk of aneusomy of recombination in the offspring. The risk of aneusomy became very important when the inverted segment was >50% of the chromosome length. Studies on spermatozoa from inversion carriers help in the comprehension of the mechanisms of meiotic segregation. They should be integrated in the genetic exploration of the infertile men to give them a personalized risk assessment of unbalanced spermatozoa.

BACKGROUND: The cytokine/chemokine levels of individual follicular fluids (FFs) were measured to determine whether a biomarker could be linked to the developmental potential of the derived embryo. METHODS: Fluid was collected from 132 individual FFs that were the source of oocytes subsequently fertilized and transferred. In each, a bead-based multiplex sandwich immunoassay (Luminex) was used to measure 28 cytokines and chemokines simultaneously. RESULTS: Significantly higher levels of interleukin (IL-2) and interferon (IFN-gamma) were detected in FF for embryos that underwent early cleavage. IL-12 was significantly higher in FF corresponding to highly fragmented embryos and the chemokine CCL5 was significantly higher in FF related to the best quality (Top) embryos. The level of granulocyte colony-stimulating factor (G-CSF) in individual FF samples was correlated with the implantation potential of the corresponding embryo. The area under the receiver operating characteristics curve, which distinguished the embryos that definitely led to delivery from those that did not, was 0.84 (0.75-0.90) (P = 0.0001) for FF G-CSF. FF G-CSF was significantly lower in patients older than 36 years compared with those <30-year old. When the FF G-CSF was 20 pg/ml or higher, the ratio between Top and non-Top embryos was significantly higher than for the group with FF G-CSF below 20 pg/ml (45 versus 20.45%, P = 0.007). CONCLUSIONS: Individual FF composition is related to the development of the corresponding in vitro generated embryo and its potential of implantation. Individual FF G-CSF may provide a non-invasive biomarker of implantation that needs to be evaluated together with in vitro observation to select the oocyte, and hence the embryo, to transfer.

Human embryo cryopreservation represents an indispensable extension of in-vitro fertilization (IVF) programmes as long as they are based upon the recovery of a large number of oocytes. The most widely used procedures include the cryopreservation of human zygotes or embryos in early cleavage, using 1,2-propanediol and sucrose as cryoprotectants. Our results over a 10 year period (1986-1995) on 5032 thawed cycles involving 14 222 stored embryos make it possible to appraise the results and the contribution of embryo freezing to assisted reproduction. Embryos survived the freeze-thaw process in 73% of cases leading to 4590 transfers of 2.2 embryos (91% of thawed cycles). The clinical pregnancy rate per transfer was 16%, the live birth rate 12%, and the rate of babies born alive per transferred embryo was 6%. Embryo freezing monitored 10 years later produced an average of 8% of additional births. By then, 86% of stored embryos had been thawed for transfer to patients. Destruction or donation were required for only 8% of all frozen embryos and there was no news from the parental couple in relation to almost 6% of embryos. The fate of the vast majority of embryos was decided during the first 5 years of storage. Blastocyst cryopreservation is making new strides, thanks to co-culture systems and embryo selection. Micromanipulation procedures seem to have little impact on the outcome of embryo freezing. Human oocyte freezing is again clinically applied. Indeed, much of the concern about injuries to the oocyte structures through the freeze-thaw process do not seem to be justified, and the problems with frozen-thawed oocyte fertilization has been overcome using intracytoplasmic sperm injection (ICSI). As long as oocyte in-vitro maturation is not well controlled, better results will probably be obtained with mature oocyte cryopreservation. Emerging methods include the freezing of immature oocytes, follicles and ovarian tissue.