Cohort Of Oocytes Research Articles

Impact of sperm DNA fragmentation reduction using MACS: comparative clinical outcomes on a shared oocyte donation program

Several studies evidenced that the use of MACS (Magnetic-Activated Cell Sorting - Annexin V columns) for semen samples with high levels of DNA damage could be useful to reduce it (1). However, other studies demonstrated that there was no beneficts of using MACS. A few years ago, we published a retrospective study who showed that using MACS could improve the ongoing pregnancy rates (2) in a oocyte donation program. Thus, the present prospective controlled study aimed to evaluate the clinical outcomes using MACS in patients with sperm DNA fragmentation in a shared oocyte donation cycles. Prospective controlled study Our study population included 60 ICSI cycles (egg-shared donation program). Semen samples were previously studied to determine DNA fragmentation level by TUNEL assay. The normal value considered for TUNEL assay was 15%. Each oocyte cohort were split in two or three recipients. Semen samples with altered DNA damage were considered. Two groups were considered, altered level of DNA damage treated with MACS (Treatment, N= 34 cycles) and other recipient with altered level of DNA damage without MACS (Control, N= 26 cycles). Fertilization rate, positive ßHCG, clinical pregnancy, implantation rate and blastulation rate, were compared between groups. Statistical analysis was performed by ANOVA and chi-square as appropriate. Results are resumed in Table 1 (a p< 0.05) The use of MACS in patients with altered levels of DNA damage seems to improve the clinical outcomes. To have a better sperm quality improves embryo development and ongoing pregnancy when oocyte competence is not compromised.Tabled 1Table 1Treatment Group (MACS)Control GroupN°3426Recipients age43.1±2.942.8±2.6Male age43.9±3.343.4±3.5Oocyte Donor age27.8±2.626.6±2.9MII oocytes/Recipient6.66.5Fertilization rate (%)82.685.7DNA fragmentation (%)22.8±4.824.8±3.8Positive BHCG/transfer (%)59 (20/34)50 (13/26)Clinical pregnancy/transfer (%)56 (19/34)a31 (8/26)Implantation rate (%)41 (25/61)a23 (10/44)Blastulation rate (%)62a38 Open table in a new tab

Larger size of the oocyte cohort does not affect risk of embryo aneuploidy when using next generation sequencing (NGS)

Recent advances in comprehensive chromosomal screening technology with NGS, have enhanced our ability to identify euploid embryos with high implantation potential 1,2. Embryos with lower potential for live birth containing aneuploidy or mosaicism, are discarded or reserved. Given this improved ability of NGS to detect the number of normal embryos developing from a single cohort of oocytes, we sought to evaluate whether oocyte retrieval yield, number of mature oocytes, or number of blastocyts biopsied, correlates with euploidy rate. Retrospective cohort study. 477 in vitro fertilization (IVF) cycles performed at a large university-based center during a three-year period were evaluated. IVF cycles with planned preimplantation genetic testing (PGT) performed using NGS were included for analysis. PGT results were reported as euploid, aneuploid or mosaic. Patients were divided into approximately equal groups based on number of oocytes retrieved, number of mature oocytes, and number of blastocysts biopsied. Patients were further stratified by age according to SART criteria. The primary outcome was rate of euploid embryos per cohort. Continuous variables were evaluated using Student’s t-test and ANOVA with Tukey’s multiple comparison test. Chi-square was used to assess categorical variables. Multivariate logistical regression was performed to control for potential confounding variables. Euploidy rates differed based on number of oocytes retrieved (1-5: 23.9%, 6-10: 26.2%, 11-15: 29.5%, >16: 35.4%; p=0.03), number of mature oocytes (1-5: 19.1%, 6-10: 30.4%, 11-15: 32.6%, >16: 36.1%; p<0.01), and number of embryos biopsied (1-2: 24.3%, 3-4: 29.7%, 5-8: 35.8%, >9: 35.0%; p<0.01). After performing multivariate linear regression to control for potential confounding factors, no association between increasing oocyte yield and euploidy was appreciated (p=0.59). Similar findings were noted when analyzing euploidy rates by the number of mature oocytes (p=0.07) and embryos biopsied (p=0.43). After stratifying by age, only patients in the 38-41yo cohort were found to have higher rates of euploidy when more than 10 oocytes were retrieved, with a trend towards higher rates in the younger groups (Table). Euploidy rate is not adversely affected when more oocytes are retrieved when measured within age strata. With the advent of Leuprolide trigger, reliable cryopreservation, and FET, this finding will likely lead us to more aggressive ovarian stimulation protocols, increase the odds of a euploid blastocyst, and maximize the chance of live birth with a single ovarian stimulation.TableAge & Euploidy Rates by Number of Oocytes RetrievedAge Groups (yrs)<3535-3738-41>41Oocytes Retrieved≤10 ≥11≤10 ≥11≤10 ≥11≤10 ≥11% Euploidy36.1 47.841.2 46.219.2 28.915.9 10.9Bold: p<0.05 Open table in a new tab

Perivitelline space abnormalities in the oocyte cohort reduces implantation and pregnancy rates in intracytoplasmic sperm injection cycles

Perivitelline space abnormalities in the oocyte cohort reduces implantation and pregnancy rates in intracytoplasmic sperm injection cycles

Complex chromosomal aberrations in a fetus originating from oocytes with smooth endoplasmic reticulum (SER) aggregates

ABSTRACTThe presence of smooth endoplasmic reticulum aggregates (SERa) in the ooplasm is considered as the most severe oocyte dysmorphism due to its serious and potentially lethal outcomes in offspring. In the present case report, a couple underwent their first intracytoplasmic sperm injection (ICSI) cycle using a gonadotrophin releasing hormone (GnRH) antagonist protocol, followed by fetal ultrasound scanning and amniocentesis. SERa were observed in all oocytes retrieved. A singleton pregnancy was established. The second trimester fetal ultrasound scan revealed a female fetus with overlapping fingers in both hands, and amniocentesis was performed for the detection of chromosomal abnormalities. Comprehensive genetic analysis with the combined use of array-comparative genomic hybridization (CGH), fluoresence in situ hybridization (FISH) and conventional cytogenetics revealed a complex chromosome rearrangement (CCR) involving three break points on two chromosomes, resulting in a reciprocal translocation with a cryptic 2q31 deletion. A week following amniocentesis, there was rupture of amniotic membranes and a stillborn was delivered. This is the first case in the literature to report a CCR with concomitant 2q31 deletion resulting in a well-defined and clinically recognizable contiguous gene syndrome with an abnormal phenotype in a fetus arising from a cohort of oocytes affected by SERa. It is suggested that fertilization and transfer of oocytes with SERa should be avoided, until further research establishes whether there is a causal relationship between the presence of SERa and chromosomal abnormalities in the resulting fetus.Abbreviations: SER: smooth endoplasmic reticulum; ICSI: intracytoplasmic sperm injection; GnRH: gonadotrophin releasing hormone; CGH: comparative genomic hybridization; FISH: fluoresence in situ hybridization; FSH: follicle stimulating hormone; hCG: human chorionic gonadotrophin; OHSS: ovarian hyperstimulation syndrome; IVF: in vitro fertilization; MII: metaphase II; GV: germinal vesicle; CCR: complex chromosome rearrangement

Enquête de satisfaction des couples à propos de la vitrification ovocytaire autologue en assistance médicale à la procréation

ObjectivesWe organized a survey for in-vitro fertilization couples who beneficiated on self-preservation of part of the oocyte cohort. The main objective was to measure couples’ satisfaction. Secondary objectives were; to identify how patients had been informed; to verify that the use of the ART technique met their expectations, and how they felt about oocyte or embryo freezing. MethodsThe data were collected by a questionnaire sent electronically to couples who had undergone partial vitrification of the oocyte cohort and at least one warming cycle. The questionnaire consisted of 2 components; one for the women and another one for their husband. ResultsEighty-eight women and 62 men responded to the survey respectively, representing 50.86% and 35.84% of the targeted patients. They were satisfied with a 90% rate, men and women combined. The information we give in the center is heard by couples and is part of the trust in the medical staff. Men are more worried than women about the risks of stimulation or ovarian pick-up and are not displeased to be called upon for sperm recovery for every attempt at oocyte warming. The ambiguity of the answers on the representation of the embryo confirms what is already described, but is independent of the acceptance of freezing whether it is oocyte or embryo. ConclusionIn the same way as evaluating the results, the evaluation of patient satisfaction is useful for the implementation of therapeutic strategies and care pathways.

The molecular characterisation of mitochondrial DNA deficient oocytes using a pig model.

What are the molecular differences between mitochondrial DNA (mtDNA)-deficient and mtDNA-normal oocytes and how does mitochondrial supplementation alter these? Changes to DNA methylation in a 5' cytosine-phosphate-guanine 3' (CpG) island in the mtDNA-specific replication factor (DNA polymerase gamma (POLG)) of mtDNA-deficient oocytes mediates an increase in mtDNA copy number by the 2-cell stage that positively modulates the expression of nuclear genes, which affect cellular and metabolic processes, following autologous mitochondrial supplementation. Too few copies of mtDNA in mature oocytes can lead to fertilisation failure or preimplantation embryo arrest. mtDNA-deficient oocytes that progress to blastocyst express genes associated with poor cellular and metabolic processes, transcriptional activation and mitochondrial biogenesis. Using a pig oocyte model, we assessed mtDNA-deficient and mtDNA-normal oocytes during in vitro maturation for mtDNA variants and levels of DNA methylation in POLG. We supplemented mtDNA-deficient oocytes with autologous populations of mitochondria to determine if there were changes to DNA methylation in POLG that coincided with increases in mtDNA copy number. We assessed metaphase II mtDNA-deficient and mtDNA-normal oocytes by RNA sequencing to identify differentially expressed genes and compared their profiles to blastocysts derived from mtDNA-normal, mtDNA-deficient and supplemented mtDNA-deficient oocytes. mtDNA variant analysis (n = 24), mtDNA copy number (n = 60), POLG gene expression (n = 24), and RNA sequencing (n = 32 single; and 12 pooled cohorts of n = 5) were performed on oocytes and embryos. DNA methylation of a CpG island in POLG was determined quantitatively by pyrosequencing on oocytes to 2-cell embryos (n = 408). Bioinformatics tools were used to assess differences between mtDNA-normal and mtDNA-deficient oocytes and between mtDNA-normal and mtDNA-deficient oocytes and supplemented oocytes and their blastocyst stage equivalents. Whilst mtDNA-deficient oocytes regulated variants less stringently during maturation (P < 0.05), there were no differences in the ratio of variants in mature-stage oocytes. However, mtDNA-normal mature oocytes had significantly more molecules affected due to their higher copy number (P < 0.0001). Normal mature oocytes differently DNA methylated a CpG island in POLG compared with mtDNA-deficient oocytes (P < 0.01). Supplementation of mtDNA-deficient oocytes modulated DNA methylation at this CpG island leading to a mtDNA replication event prior to embryonic genome activation inducing significant increases in mtDNA copy number. RNA-Seq identified 57 differentially expressed genes (false discovery rate (FDR) < 0.05) between the two cohorts of oocytes with blastocyst stage gene expression altered by supplementation of mtDNA-deficient oocytes (P < 0.05) including genes associated with metabolic disorders. One key factor was branched chain amino acid transaminase 2 (BCAT2), a regulator of amino acid metabolism and associated with diabetes. Sequence data are available on the NCBI Sequence Read Archive under the project number PRJNA422295. RNA sequencing data were deposited into NCBI Gene Expression Omnibus, under the accession number GSE108900. Whilst this work was conducted in a species that is highly relevant to human reproduction, the outcomes need to be tested in human oocytes and blastocysts prior to clinical application. The outcomes demonstrate a mechanism of action following mtDNA supplementation of mtDNA-deficient oocytes that results in improved gene expression at the blastocyst stage of development. This work was funded by OvaScience Inc. OvaScience did not influence the study design, analysis of results or interpretation of the data.

Prospective assessment of follicular growth and the oocyte cohort after ovarian stimulation for fertility preservation in 90 cancer patients versus 180 matched controls.

A lower number of metaphase II oocytes eligible for vitrification after controlled stimulation in cancer patients has recently been reported, suggesting that cancer may impair the dynamics and quality of follicular growth. In this prospective, non-interventional study, the pattern of follicular growth and oocyte cohort after ovarian stimulation in cancer patients was analysed. Ninety cancer patients, recruited before starting chemotherapy, were compared with 180 time- and age-matched healthy controls undergoing intracytoplasmic sperm injection. Primary outcome was total number of metaphase II oocytes and metaphase II /total oocytes rate. Basal anti-Müllerian hormone levels (P < 0.05) and antral follicle count (P < 0.0001) were significantly lower in cancer patients. Recombinant FSH total dose was significantly higher in the cancer group (P < 0.0001). No differences were found in duration of stimulation, mean number of mature follicles on day of ovulation induction and total oocyte number after retrieval; the number of metaphase II oocytes retrieved (6.2 ± 4.7 versus 8.8 ± 4.2; P < 0.0001) and number of metaphase II oocytes-total oocytes ratio were significantly lower in cancer patients (56% versus 78%, P < 0.0001). Fewer metaphase II oocytes were eligible for vitrification and lower maturation rate in the cancer group.

Evaluating the use of the autodiametric method for estimating fecundity of Reinhardtius hippoglossoides, a species with an unusual oocyte development strategy

Abstract The autodiametric method is a highly streamlined method for estimating fecundity of fish with determinate oocyte development pattern. Greenland halibut presents a peculiar reproductive strategy with two simultaneously cohorts one of large vitellogenic oocytes (for the current year) and another one of small vitellogenic oocytes (for the subsequent year). Results of this study showed that autodiametric method can be applied to estimate fecundity in Greenland halibut. Additionally, spatial differences in the autodiametric calibration curve were observed in the Northwest Atlantic, but did not translate into differences in fecundity at length. This is the first time that spatial differences between ACCs of the same species have been reported, what could be the result of (i) the unusual oocyte development pattern, or (ii) spatial differences in oocyte biochemistry. More research on the relative dynamics of oocyte cohorts simultaneously present in Greenland halibut ovaries and the factors (endo- or exogenous) influencing oocyte packing density could provide a better understanding of observed geographical differences.

Impact of oocytes with CLCG on ICSI outcomes and their potential relation to pesticide exposure

BackgroundOocyte quality is a key limiting factor in female fertility which is primarily reflected in morphological features. Centrally located cytoplasm granulation (CLCG) is one type of cytoplasmic dimorphism exhibited by oocytes that could be linked to pesticide exposure with a significant risk of decreased ICSI outcomes.MethodsThis retrospective study included 633 women who were part of an intracytoplasmic spermatozoa injection (ICSI) program between 2009 and 2011. The participants lived in the Picardy region of France and had been exposed to pesticides. The participants were divided in two groups based on prevalence of oocytes with CLCG (LCLCG [n = 83]: low prevalence of oocytes with CLCG under 25%. HCLCG [n = 68]: high prevalence of CLCG over 75%). The embryological and clinical outcomes were analysed for both groups and were calculated using the difference between the two values.ResultsResults for couples with HCLCG compared to LCLCG showed a decrease in embryo cleavage, ongoing pregnancy, and live birth rates (82%, 14%, 13% vs 99%, 32%, 30%, respectively).The early miscarriage rate was increased (47% vs 11%), with an OR of 3.1 (95%CI [2.1–4.1]). Due to high pesticide exposure (over 3000 g/ha), there is a higher risk of a resulting disturbed oocyte cohort with a high prevalence of CLCG over 75%.ConclusionThe high prevalence of oocytes with CLCG over 75% has a negative effect on embryos and the general ICSI clinical outcomes. Furthermore, a putative association between pesticide exposure and risk of CLCG was identified, justifying the need for further research and a potential need to find alternative assisted reproductive technologies for these couples.Trial registrationTabacfertimasc. ID number: ID2011-A00634–37; registered 2011/2/8

Larger donor oocyte cohorts maximize potential number of live born infants per retrieval among recipient in vitro fertilization (IVF) patients

Larger donor oocyte cohorts maximize potential number of live born infants per retrieval among recipient in vitro fertilization (IVF) patients

Retrieval of larger oocyte cohorts maximizes in vitro fertilization (IVF) birth rates per cycle

Retrieval of larger oocyte cohorts maximizes in vitro fertilization (IVF) birth rates per cycle

Revisiting oolemma characteristics during ICSI in relation to fertilization patterns and embryo development and implantation

The oolemma response during ICSI has been linked to membrane and cytoplasmic maturity. The former is evidenced by the depth of the funnel and can manifest in the unextrusion of the second polar body and oocyte lysis, while the latter in absent fertilization. We investigate the occurrence of normal and abnormal fertilization patterns, as well as oocyte survival in relation to ovarian stimulation and eventual reproductive outcomes. In couples with an adequate cohort of mature oocytes and varying degrees of fertilization, we measured the occurrence of immature membrane and ooplasm (as evident by oocyte lysis), impaired cytoplasmic maturity (as evident by no fertilization), lower membrane maturity (as evident by 3PN embryos) and complete membrane and cytoplasmic maturity (2PN). Only ICSI cycles with >5 oocytes at MII stage were included. Unextrusion of the second polar body, characterized by digynic 3PN, is associated with sudden breakage of the membrane, short funnel, and indicates ooplasmic maturity but membrane dysmaturity. Oocyte lysis is characterized by absence of funnel development and therefore severe membrane dysmaturity. Absent fertilization presented with adequate funnel development up to the center of the oocyte therefore allowing oocyte survival, but unfortunately with ooplasmic immaturity. ICSI cycles were stratified by fertilization rates, in increments of 20%. The rates of 3-PN embryos and oocyte lysis were plotted against increasing fertilization rates. Demographics and ovarian stimulation parameters were compared across fertilization groups. 11911 ICSI cycles were identified. The rate of digynic 3PN embryos decreased with increasing fertilization rate [7.19% (<20%) to 1.10% (81-100%)]. Similar trends in the rate of oocyte lysis were observed as well. There was no difference in the median age of patients (36), number of oocytes (9), or total stimulation days (10) across different fertilization groups. Patients with oocyte lysis had a progressively lower dose of gonadotropins (P=0.007) and peak E2 levels (P<0.001) in comparison to those that had no fertilization, digynic 3PN embryos, and both membrane and cytoplasmic maturity (all 2PN). To assess the impact of oolemma/ooplasmic maturity within the cohort of oocyte injected on the embryo developmental outcome, we compared patients with oocyte lysis to those who had normal fertilization (n=384). Lower implantation (16.7% vs. 32.4%; P<0.001) and clinical pregnancy rates (7.01% vs. 34.6%; P<0.001) were noted in the former group compared to the latter. During ICSI, membrane funnel characteristics may provide insight into oolemma maturity. Oocyte survival, absent/abnormal fertilization provides invaluable information about ooplasmic maturity and embryo developmental competence. Our study highlights the potential link between oolemma behavior, absent/abnormal fertilization and ovarian stimulation.

Biological variables of Hypostomus francisci (Siluriformes: Loricariidae) from Itapecerica River, Minas Gerais State, Brazil.

Herein we determine for the first time the reproduction parameters and population structure of Hypostomus francisci in the Itapecerica River, São Francisco Basin. A total of 250 specimens was captured quarterly between March 2010 and February 2012. Body weight, total length and weight of the gonads were obtained in the laboratory. Gonad samples were submitted to histological and histochemical techniques. Females with spawning capable ovaries were used to determine the fecundity and relative fecundity. Sex ratio with 1:1.01 (female:male) was observed. Males were more numerous than females for individuals smaller than 170 mm, however the number of females was significantly greater for specimens larger than 330 mm. The length-weight relationship estimated for H. francisci indicates negative-allometric growth. Females spawning capable were observed mostly in November-December-January. Two cohorts of oocytes at a determined time evidencing the development type group-synchronic. The eggs reaching 3.4 mm and the fecundity ranged from 312-1,460 oocytes with an average of 585.81 ± 337.43 oocytes per female. The reproductive parameters and population structure of H. francisci from Itapecerica River suggested that this species showed singular reproductive tactics among congeners.

Ultrastructural and cytogenetic analyses of mature human oocyte dysmorphisms with respect to clinical outcomes.

The study aimed to describe the ultrastructure of two human mature oocyte intracytoplasmic dysmorphisms, the bull-eye inclusion and the granular vacuole, with evaluation of clinical outcomes after intracytoplasmic sperm injection (ICSI) treatment. We retrospectively evaluated 4099 consecutive ICSI cycles during the period 2003-2013. Three groups were compared: controls, those with a bulls-eye inclusion, and those with granular vacuoles. Oocyte dysmorphisms were evaluated by transmission electron microscopy and in situ fluorescence hybridization (FISH). Detailed data on demographic and stimulation characteristics, as well as on embryological, clinical, and newborn outcomes, are fully presented. The bull-eye inclusion is a prominent smooth round structure containing trapped vesicles, being surrounded by lipid droplets. The presence of this dysmorphism in the oocyte cohort had no clinical impact except when transferred embryos were exclusively derived from dysmorphism oocytes. The granular vacuole is delimited by a discontinuous double membrane and contains lipid droplets and vesicles. As FISH analysis revealed the presence of chromosomes, they probably represent pyknotic nuclei. The presence of this dysmorphism in the oocyte cohort had no clinical impact except when at least one transferred embryo was derived from dimorphic oocytes. Poor clinical outcomes were observed with transfer of embryos derived from dysmorphism oocytes, although without causing gestation or newborn problems. The bull-eye inclusion and granular vacuoles may thus be new prognostic factors for clinical outcomes.

Parameter Estimations of Dynamic Energy Budget (DEB) Model over the Life History of a Key Antarctic Species: The Antarctic Sea Star Odontaster validus Koehler, 1906

Marine organisms in Antarctica are adapted to an extreme ecosystem including extremely stable temperatures and strong seasonality due to changes in day length. It is now largely accepted that Southern Ocean organisms are particularly vulnerable to global warming with some regions already being challenged by a rapid increase of temperature. Climate change affects both the physical and biotic components of marine ecosystems and will have an impact on the distribution and population dynamics of Antarctic marine organisms. To predict and assess the effect of climate change on marine ecosystems a more comprehensive knowledge of the life history and physiology of key species is urgently needed. In this study we estimate the Dynamic Energy Budget (DEB) model parameters for key benthic Antarctic species the sea star Odontaster validus using available information from literature and experiments. The DEB theory is unique in capturing the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model allows for the inclusion of the different life history stages, and thus, becomes a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. The DEB model presented here includes the estimation of reproduction handling rules for the development of simultaneous oocyte cohorts within the gonad. Additionally it links the DEB model reserves to the pyloric caeca an organ whose function has long been ascribed to energy storage. Model parameters described a slowed down metabolism of long living animals that mature slowly. O. validus has a large reserve that—matching low maintenance costs- allow withstanding long periods of starvation. Gonad development is continuous and individual cohorts developed within the gonads grow in biomass following a power function of the age of the cohort. The DEB model developed here for O. validus allowed us to increase our knowledge on the ecophysiology of this species, providing new insights on the role of food availability and temperature on its life cycle and reproduction strategy.

Morphokinetics analysis of embryos derived from vitrified/warmed oocytes.

Oocyte vitrification is a worldwide used technique that has proved its worth. Although it was shown not to alter oocyte integrity, a recent study concluded that it may affect oocyte embryo development. As the morphology and kinetics of embryos derived from sibling fresh and vitrified oocytes have not been described previously, the present study evaluates cleavage rate, blastomeres size, fragmentation rate, and blastocyst formation in vitrified/warmed oocyte derived embryos (VODE) as compared with sibling fresh oocytes derived embryos (FODE). This investigation included 90 infertility cases displaying large cohort of mature oocytes at pick up, divided into 2 groups after denudation. A part of oocytes underwent ICSI while others were vitrified. Oocyte warming cycles were performed when no pregnancy was achieved using fresh eggs. Zygote to blastocyst development was recorded prospectively in an image database up to day 5. VODE did not show major difference as compared with FODE in terms of cleavage rate, number of blastomeres, fragmentation rate, and blastomeres size. Furthermore, percentage of morulae at day 4 and blastocysts at day 5 are not affected by oocyte vitrification. Although our results show that embryo development is not altered by oocyte vitrification, offspring follow-up is essential to exclude any adverse developmental effect of the technique.

Asynchronous reproduction and multi-spawning in the coral-excavating sponge Cliona delitrix

Cliona delitrix is one of the most abundant and destructive coral-excavating sponges on Caribbean reefs. However, basic aspects of its reproductive biology, which largely determine the species propagation potential, remain unknown. A 2-year study (October 2009 to September 2011) was conducted to determine the reproductive cycle and gametogenesis of a C. delitrix population located in a shallow reef in Florida, USA. Mesohyl tissue collected from randomly chosen and tagged sponge individuals was sampled one to several times a month, and analysed by light and transmission electron microscopy (TEM). Cliona delitrix is oviparous and gonochoric, except for a few simultaneous hermaphroditic individuals. The C. delitrix reproductive cycle in Florida is from April to December, and is triggered by an increase in seawater temperature to 25°C. Oogenesis and spermatogenesis were asynchronous among individuals; with different cohorts of oocytes co-occurring in females, and spermatic cysts in males. Granulose cells acted as nurse cells, contributing to the growth and maturation of both female and male gametes. Spawning of gametes was not always synchronized with full moon phase. Unlike most other oviparous sponges, the reproductive cycle of C. delitrix is versatile and includes multiple spawning events during the summer of each year. This characteristic maximizes sponge propagation on coral reefs during the warmer months of the year, particularly when thermal stress induces coral mortality. This aspect, combined with its success on polluted areas, make C. delitrix a suitable bioindicator of coral reef health.

Intracytoplasmic sperm injection (ICSI) in extreme cases of male infertility.

IntroductionSeverely compromised spermatogenesis typical of men with virtual azoospermia or non-obstructive azoospermia requires an extreme search for spermatozoa. Our goal was to evaluate the usefulness of a meticulous search carried out in ejaculated or surgically retrieved specimens in achieving pre- and post-implantation embryo development.Patients and MethodsIn a retrospective cohort study carried out in an academic institution, intracytoplasmic sperm injection (ICSI) outcomes were reviewed as a function of length of microscopic sperm search in ejaculated and surgically retrieved specimens. Couples whose male partner presented with either virtual or non-obstructive azoospermia were treated by ICSI and categorized according to the time spent in identifying and retrieving enough spermatozoa to inject all the oocyte cohort. Semen parameter, fertilization, pregnancies, deliveries, and child welfare in relation to increasing search time were analyzed and compared.Result(s)The maternal and paternal ages were comparable in both ejaculated and testicular sperm extraction (TESE) groups along with the oocytes retrieved. The fertilization rates for both ejaculated and TESE progressively decreased with increasing time (P<0.0001). Clinical pregnancies in the ejaculated cohort remained satifactory. In the TESE cohort, there was a decrease in pregnancy rate with increasing time, from 44% to 23%. In a limited number of cases, offspring health was evaluated in both semen sources and appeared reassuring.Conclusion(s)An extensive and at time exhaustive sperm quest yields kinetically and morphologically impaired spermatozoa without apparent impact on embryo developmental competence. Retrieval of spermatozoa from the seminiferous tubules provided more consistent fertilization and pregnancy outcomes than those retrieved from the ejaculate. A trend indicated that pregnancy rate decreased as search time increased in the TESE group. The utilization of the scarce and unselected spermatozoa did not obviously impair embryo development or cause post-implantation errors.

Protracted oogenesis and annual reproductive periodicity in the deep‐sea pennatulacean Halipteris finmarchica (Anthozoa, Octocorallia)

AbstractHalipteris finmarchica is one of the most common species of deep‐sea pennatulacean corals in the Northwest Atlantic; it was recently determined to act as a biogenic substrate for other species and as a nursery for fish larvae. Its reproductive cycle was investigated in colonies sampled in 2006 and 2007 along the continental slope of Newfoundland and Labrador (Canada). Halipteris finmarchica exhibits large oocytes (maximum diameter of 1000 μm), which are consistent with lecithotrophic larval development. Female potential fecundity based on mature oocytes just before spawning was ~6 oocytes · polyp−1 (500–6300 oocytes · colony−1); male potential fecundity was 16 spermatocysts · polyp−1 (5500–57,400 spermatocysts · colony−1). Based on statistical analysis of size‐probability frequency distributions, males harboured one cohort of spermatocysts that matured inside 8–11 months, whereas females harboured two distinct cohorts of oocytes; a persistent pool of small ones (≤400 μm) and a small number (~20%) of larger ones that grew from ~400 to &gt;800 μm over a year. Despite this difference in the tempo of oogenesis and spermatogenesis, a synchronic annual spawning was detected. A latitudinal shift in the spawning period occurred from south (April in the Laurentian Channel) to north (May in Grand Banks and July–August in Labrador/Lower Arctic), following the development of the phytoplankton bloom (i.e. sinking of phytodetritus). Prolonged oogenesis with the simultaneous presence of different oocyte classes in a given polyp is likely not uncommon in deep‐sea octocorals and could hamper the detection of annual/seasonal reproduction when sample sizes are low and/or time series discontinued or brief.

Examining the temperature of embryo culture in in vitro fertilization: a randomized controlled trial comparing traditional core temperature (37°C) to a more physiologic, cooler temperature (36°C)☆

To determine whether culture at a more physiologically cooler temperature, as suggested by limited human and animal data, would improve blastulation and pregnancy rates in human clinical IVF. Paired randomized controlled trial. Academic. Infertile couples (n=52) with a female partner less than 42 years old with eight or more mature oocytes retrieved. Mature oocytes obtained from a single cohort of oocytes were randomly divided into two groups; one was cultured at 37°C and the other at 36°C from the time of ICSI to the time of embryo transfer or vitrification. Paired embryo transfers were accomplished by transferring one euploid embryo from each group. DNA fingerprinting was used as needed to determine the outcome for each embryo. Rate of development of expanded blastocysts suitable for transfer or vitrification (primary outcome), fertilization, aneuploidy, and sustained implantation. A total of 805 mature oocytes were cultured; 399 at 36°C and 406 at 37°C. Paired analysis demonstrated a higher rate of usable blastocyst formation per zygote at 37°C (48.4%) vs. at 36°C (41.2%). Rates of fertilization, aneuploidy, and sustained implantation were equivalent. IVF culture at 36°C does not improve clinically relevant parameters of embryo development or sustained implantation rates. NCT01506089.