Gametic Selection Research Articles

The role of genotype and viral agents in the formation of tomato tolerance to high temperatures

Research results are presented to determine the sources of variation that cause microgametophyte variability in the progeny of plants reinfected with viruses (Tobacco Mosaic Virus/TMV or Tomato Aspermy Virus/TAV) under high temperatures. The heat treatment of pollen grains contributed to the modifications of the functional characteristics, which in most cases were manifested by inhibitory effects. The factors that cause the variation of genotype characteristics at the diploid and haploid levels have been established. It was demonstrated that the reaction of the analyzed genotypes to the heat treatment at the seed germination stage was controlled by the genotype as major influence, and heat factor, which enhances the efficient identification of tolerant forms. Genotypes that showed high reproductive potential under high temperatures were highlighted. It was established that the descendants of the infected plants at the male gametophyte and sporophyte stages exceeded the control values according to the level of heat stress tolerance, which is due to the elimination of the pollen grains with reduced viability from the host plant in the previous generation. Thus, the application of gametic selection methods in breeding programs is of major importance for reducing the negative action of high temperatures, both in healthy and virus-infected/reinfected plants and their progeny.

P-230 Use of a novel in vivo biosensor to rapidly determine oocyte developmental competence

Abstract Study question Can a novel in vivo biosensor (IVOS) rapidly determine oocyte developmental competence? Summary answer Data collected with the IVOS biosensor can be used to determine oocyte developmental competence, observed as blastocyst development after in vitro embryo production. What is known already Methods allowing for rapid, non-invasive assessment of oocyte quality are limited. Subjective morphology is used for gamete selection, but cannot discern between cells with subcellular dysfunction. Metabolism is an accurate method to distinguish cellular quality, but current methods are not rapid, require highly artificial environments, or lack appropriate sensitivity. Extracellular indicators associated with metabolic output may correlate to inherent oocyte developmental potential and serve as a biomarker. A published in vivo biosensor (IVOS) which analyses REDOX homeostasis, an indicator of subcellular function, may be optimised to use at the cellular level to assess oocyte quality. Study design, size, duration Experiments were performed in South Australia using abattoir derived cumulus-oocytes complexes (COC) aspirated from ewe ovaries for in vitro embryo production. COCs were group matured then maintained individually after IVOS analysis to permit identification of oocyte measurements to embryo developmental endpoint. Methodology optimisation and experiments were performed in June 2023 and October 2023, respectively. A holding pipette was modified to permit compatibility with the IVOS system using a proprietary method. Participants/materials, setting, methods Matured COCs were denuded to the corona radiata and placed into an air-buffered medium for IVOS analysis. The holding pipette suctioned COCs prior to excitation (488nm) of extracellular molecules at the COC surface. Emission wavelengths (515-520nm) were retrieved for ten consecutive replicates. COCs were subsequently co-incubated with frozen-thawed ram semen. Presumptive zygotes were cleaned of cumulus cells and loose spermatozoa, cultured for seven days, and stained using Hoechst H33342 to obtain total cell number. Main results and the role of chance Embryos were graded into three categories: 1) did not display a blastocoel cavity (not blastocyst); 2) embryo displaying a blastocoel and total cell count below 50 (early blastocyst); and 3) embryo displaying a blastocoel with a total cell count above 50 (blastocyst). Standard deviation calculations for technical replicates of each COC (n = 32) were used to form an equation capable of distinguishing between groups based on developmental endpoint reached. From this equation, IVOS measurements were lower in oocytes reaching the early blastocyst stage compared to those which reached the blastocyst stage (P < 0.001) or did not reach the blastocyst stage (P = 0.042). Data from oocytes that became full blastocysts were higher than those which did not become blastocysts (P = 0.031). Limitations, reasons for caution The technology used in this study has been tested on sheep oocytes using blastocyst development as a measure of developmental competence. Further research is required to determine if it is applicable to other species or reproductive outcomes such as pregnancy and live birth. Wider implications of the findings This study provides a new technology and optimised methodology to improve the selection of high-quality oocytes among gametes graded homogeneously using subjective morphology. It can be utilised with existing assisted reproductive technologies to possibly increase the success rate of these procedures. Trial registration number N/A

P-497 Increasing use of pan-ethnic carrier screening for donor gametes creates new challenges for clinics and recipient counselling

Abstract Study question How can clinics support recipients to understand a positive or negative carrier status following pan-ethnic carrier screening. Summary answer A combination of recipient testing and genetic counselling enables the use of donor sperm irrespective of pan-ethnic screening results. What is known already Data reported by the HFEA, UK reveals that in 2020, more than half of new donor registrations were from donor imports - 48% were American or Danish in origin, where the level of genetic screening for recessive conditions can vary from 3 to 502 genes. Donor banks generally state that donors are screened to professional guidelines for the countries they supply. Variations in the practice for carrier screening of gamete donors and how this information is shared and charged can be opaque to clinics and complex for recipients to navigate without specialist support to understand relevance and reproductive risk. Study design, size, duration This study reports on the number of genetic counselling requests from several IVF clinic referrals in the UK for the period Jan 2020 - Dec 2023. A total of 412 recipients interested in purchasing samples from donors identified as a positive carrier of one or more recessive condition(s) after undergoing extended carrier screening. Referrals for ECS negative donors were not received. Participants/materials, setting, methods Recipients were provided with the opportunity of genetic counselling to include the meaning of the carrier status, risk estimates, and options. Recipients were then given the opportunity to review the consultation report and were supported through their subsequent decision-making. The recipient’s choice to accept the risk for using the donor or proceed to counter-screening was evaluated to give insight into the recipient decision-making for accepting risk or wishing to undertake carrier screening. Main results and the role of chance UK screening recommendations cumulatively account for only 9.3% of identified mutations within a sperm donor applicant population at a single commercial US sperm bank screened using ECS, highlighting international inconsistencies in donor recruitment and acceptance criteria. 15.3 % (n = 63) of recipients elected to be screened for the conditions their donor was a carrier for, with most opting to be screened on a matched gene panel to provide information for a child and allow future matching with an alternative donor. 84.7% (n = 359) proceeded with treatment without counter screening appreciating their relatively low reproductive risk. Patients who undertake consultation with a genetic professional can understand their reproductive risk for autonomous decision-making, indicating ECS positive results are not a barrier to donor gamete selection for treatment. Limitations, reasons for caution ECS panels are variable by commercial provider, donor banks may vary their carrier screening policy or commercial ECS options over time, limiting the findings to the time frame in which the abstract was written Wider implications of the findings Review and implementation of carrier screening guidelines are required to ensure consistency and transparency with access to suitably qualified genetics professionals to provide information counselling and genetic testing options. This allows recipients to maintain a level of autonomy for donor selection and may ultimately widen the available donor pool. Trial registration number not applicable

A survey study evaluating donor gamete utilization rates, patient satisfaction, and fertility treatment outcomes according to desired race and ethnicity

To evaluate donor gamete utilization, patient satisfaction, and fertility treatment outcomes of patients pursuing treatment with donor gametes stratified by the desired race as well as ethnicity of the gamete donor. Survey study. Clinic. Patients planning to undergo treatment using donor sperm and/or donor oocytes at a single academic fertility clinic in the Southeastern United States between 2015 and2020. None. Utilization rates of donor gametes, satisfaction with donor gamete selection, and fertility treatment outcomes stratified by race and ethnicity of patient, as well as that of their gamete donor. Four hundred fifty patients were eligible for inclusion and 170 (38%) responded to the survey. Among the respondents, 59% desired a non-Hispanic White gamete donor and 20% desired a non-Hispanic Black gamete donor. Patients seeking a non-Hispanic Black gamete donor had lower odds of using donor gametes (Odds ratio [OR], 0.13; 95% confidence interval [CI], 0.04-0.40) compared with individuals seeking a non-Hispanic White gamete donor. When evaluating satisfaction with donor gamete selection, patients seeking a non-Hispanic Black gamete donor reported lower satisfaction compared with individuals seeking a non-Hispanic White gamete donor (OR, 0.19; 95% CI, 0.09-0.43). When evaluating fertility outcomes, Non-Hispanic Black patients and those using non-Hispaninc Black gamete donors were found to have lower odds of successful conception compared with non-Hispanic White patients (OR, 0.18; 95% CI, 0.07-0.46) and individuals seeking non-Hispanic White gamete donors (OR, 0.26; 95% CI, 0.09-0.75), respectively. Patients seeking non-Hispanic Black donor gametes have lower utilization rates, less satisfaction with gamete donor selection, and lower odds of conception when compared with those seeking non-Hispanic White gamete donors. These findings highlight the need for more racial diversity within donor gamete banks, as well as within the donor pools available through agencies and fertility clinics.

Analysis of Elimination Effects of Inbreeding on Genotype Frequency in Larval Stages of Chinese Shrimp.

Marine animals possess genomes of considerable complexity and heterozygosity. Their unique reproductive system, characterized by high fecundity and substantial early mortality rates, increases the risk of inbreeding, potentially leading to severe inbreeding depression during various larval developmental stages. In this study, we established a set of inbred families of Fenneropenaeus chinensis, with an inbreeding coefficient of 0.25, and investigated elimination patterns and the manifestations of inbreeding depression during major larval developmental stages. Reduced-representation genome sequencing was utilized to explore the genotype frequency characteristics across two typical elimination stages. The results revealed notable mortality in hatching and metamorphosis into mysis and post-larvae stages. Inbreeding depression was also evident during these developmental stages, with depression rates of 24.36%, 29.23%, and 45.28%. Segregation analysis of SNPs indicated an important role of gametic selection before hatching, accounting for 45.95% of deviation in the zoea stage. During the zygotic selection phase of larval development, homozygote deficiency and heterozygote excess were the main selection types. Summation of the two types explained 82.31% and 89.91% of zygotic selection in the mysis and post-larvae stage, respectively. The overall distortion ratio decreased from 22.37% to 12.86% in the late developmental stage. A total of 783 loci were identified through selective sweep analysis. We also found the types of distortion at the same locus could change after the post-larvae stage. The predominant shifts included a transition of gametic selection toward normal segregation and other forms of distortion to heterozygous excess. This may be attributed to high-intensity selection on deleterious alleles and genetic hitchhiking effects. Following larval elimination, a greater proportion of heterozygous individuals were preserved. We detected an increase in genetic diversity parameters such as expected heterozygosity, observed heterozygosity, and polymorphic information content in the post-larvae stage. These findings suggest the presence of numerous recessive deleterious alleles and their linkage and suggest a major role of the partial dominance hypothesis. The results provide valuable insights into the mechanisms of inbreeding depression in marine animals and offer guidance for formulating breeding strategies in shrimp populations.

Gametic selection favours polyandry and selfing.

Competition among pollen or sperm (gametic selection) can cause evolution. Mating systems shape the intensity of gametic selection by determining the competitors involved, which can in turn cause the mating system itself to evolve. We model the bidirectional relationship between gametic selection and mating systems, focusing on variation in female mating frequency (monandry-polyandry) and self-fertilisation (selfing-outcrossing). First, we find that monandry and selfing both reduce the efficiency of gametic selection in removing deleterious alleles. This means that selfing can increase mutation load, in contrast to cases without gametic selection where selfing purges deleterious mutations and decreases mutation load. Second, we explore how mating systems evolve via their effect on gametic selection. By manipulating gametic selection, polyandry can evolve to increase the fitness of the offspring produced. However, this indirect advantage of post-copulatory sexual selection is weak and is likely to be overwhelmed by any direct fitness effects of mating systems. Nevertheless, gametic selection can be potentially decisive for selfing evolution because it significantly reduces inbreeding depression, which favours selfing. Thus, the presence of gametic selection could be a key factor driving selfing evolution.

P-093 Single sperm morphokinetic variables during ICSI at the time of sperm aspiration into the microneedle

Abstract Study question Is it possible to classify sperm morphology as normal or abnormal based on their kinetic characteristics? Summary answer Using different classifiers, it was found that balanced dataset the classification scores of individual sperm morphology can be optimized during their motility just before ICSI What is known already Sperm selection plays a crucial role during ICSI. This selection by the embryologists is accompanied by two factors: motility parameters of the sperm to be injected, as well as the morphology. Motility affects morphological decision-making which may be subjective due to spermatozoa not being in a narrow vertical space in a PVP droplet, i.e. counting chamber. Machine/Deep Learning models -as classifiers- are gaining popularity in IVF as it could minimize subjectivity in gamete selection. SiD software is an algorithm that from a group of spermatozoa characteristics can support the selection of a single sperm during real time ICSI. Study design, size, duration In this prospective study 1699 individual spermatozoa were video-recorded (resolution of 200 X 200 pix.) during sperm selection in a 7%PVP solution. Motility variables (VSL, VCL, LIN, VAP, ALH, WOB, STR, MAD) were obtained from each video using the software SiD. Each sperm was classified as normal or abnormal. Based on motility variables, different classification models were used to make a morphokinetic association of the variables with the classification of each sperm. Participants/materials, setting, methods 1699 individual spermatozoa were classified and labeled by three senior embryologists into two categories: normal or anormal. To belong to any category, at least two embryologists had to agree. A normalization was applied to the motility data obtained with SiD. Machine learning classification models were applied. The three classification models with the best results were selected to optimize the hyper-parameters and improve their performance. Main results and the role of chance A set of motility variables were obtained using the software SiD1 (IVF2.0 Ltd., UK) these were used as features for each of the sperm samples and were tagged either as normal or abnormal having a total of 257 normal samples and 1442 abnormal samples. Different classification algorithms were used to perform sperm classification as normal and abnormal. Then hyperparameter tuning algorithms such as GridSearch were used to compute the optimum values, finding KNN algorithm to achieve the best results to classify normal and abnormal spermatozoa with 80% accuracy. Given the nature of the unbalanced dataset, the F1 score was calculated, achieving 0.77, other algorithms such as Decision-Tree and Random-Forest were used achieving similar results in the F1 score. We will continue growing the dataset until it is balanced and run the same algorithms expecting the performance to improve. Limitations, reasons for caution Each clinic's laboratory setup, including the camera used to record the ICSI procedure, is a clinic-specific configuration. Sperm abnormality detection is sensitive to camera resolution, showing the classifiers are resolution-dependent observers. To replicate these results, it is important to consider the quality of the camera. Wider implications of the findings Using the selected kinematics features, it is possible to classify individual spermatozoa during motility as having normal or abnormal morphology. Results may improve using standard morphological examination of each population and having more normal sperm samples. Trial registration number Not applicable

P-795 Identification of a specific paternal haplotype in the germline and perpetuating progenies by male gamete replication

Abstract Study question Can we identify and replicate a male germ cell genome to generate progenies carrying a specific genotype? Summary answer We were able to replicate male genome and identify the androgenote with a specific genotype to generate conceptuses with identical paternal haplotype. What is known already For patients with heritable genetic disorders, current treatment relies on preimplantation genetic testing for monogenic disorders (PGT-M) to select unaffected embryos for replacement; however, this can lead to embryo wastage, causing emotional distress. Although genomic editing of gametes is being attempted, CRISPR-based technologies are inaccurate and can lead to loss of heterozygosity in cases where the embryo uses the maternal genome as a template to edit the paternal genome. Therefore, the use of haploid androgenotes may offer a useful tool to select male gametes with genes of interest or a successfully edited genome before the creation of an embryo. Study design, size, duration To generate haploid androgenotes, spermatozoa from hemizygous transgenic mice with GFP expression (B6-EGFP x B6D2F1) were used to inseminate enucleated wildtype oocytes. Constructs were cultured to the 8-cell stage. Two pseudo-blastomeres were isolated for genotyping by DNAseq. A blastomere with GFP expression was used as a male gamete. Experiments were repeated using mice with the Fbn1tm1Hcd mutation as a model for Marfan syndrome. Biparental embryos were created to preserve the mutation as a disease model. Participants/materials, setting, methods To generate haploid androgenotes, metaphase II oocytes from wildtype B6 mice were enucleated and inseminated using spermatozoa from hemizygous GFP transgenic mice. Haploid androgenetic embryos were cultured in a time-lapse incubator up to the 8-cell stage. Biparental embryos were created by fusing a selected androgenote with an activated oocyte from another cohort. Resulting embryos were genotyped to confirm the paternal haplotype. Experiments were reproduced using spermatozoa from heterozygous Fbn1tm1Hcd-mutant mice. Main results and the role of chance In the first set of experiments using spermatozoa from transgenic mice hemizygous of GFP, 200 wildtype oocytes were enucleated and generated 195 (97.5%) ooplasts. Insemination of those ooplasts yielded 168 (86.2%) monopronucleated androgenetic embryos, and subsequently generated 116 (69.0%) 8-cell haploid androgenetic embryos, of which 59 (50.8%) expressed GFP. Up to 2 sibling blastomeres were genotyped individually by DNAseq and confirmed to have an identical paternal haplotype. The remaining blastomeres were used to create biparental embryos and yielded a 97.2% fertilization rate after grafting into 145 oocytes, comparable with the fertilization rate of ICSI controls at 95.6%. Although control zygotes yielded an 88.0% blastulation rate, the experimental embryos yielded a lower blastulation rate of 58.2% (P<0.0001). Albeit with a lower developmental rate, all experimental blastocysts expressed GFP and displayed normal embryo morphokinesis. For the experiment using spermatozoa from Fbn1tm1Hcd mice, 50 8-cell stage haploid androgenetic embryos were generated. Two individual pseudo-blastomeres from 35 haploid embryos were used for genotyping. The remaining 210 haploid blastomeres were used to construct biparental embryos and yielded 119 (56.7%) blastocysts. PCR on embryo biopsies confirmed that the resulting blastocysts inherited the mutant (n = 63) or wildtype (n = 56) paternal haplotype from the original gamete. Limitations, reasons for caution This technique allowed the selection of male gametes with the desired genotype to generate conceptuses with a known haplotype in a reproducible manner. A more prospective experiment is ongoing to simulate clinical application by cryopreserving haploid androgenetic embryos and using only androgenotes with a confirmed genotype to create biparental embryos. Wider implications of the findings This approach to utilize gamete substitutes before fertilization ensures the maintenance of rare and unique genetic materials to generate conceptuses with the desired genotype in transgenic mice in disease models. Indeed, once this technique is implemented in humans, genotyped androgenotes can be used to characterize germline heterozygosity. Trial registration number N/A

Thirty years of ICSI: quality assessment and selection of gametes and embryos. Where are we in 2023?

Thirty years of ICSI: quality assessment and selection of gametes and embryos. Where are we in 2023?

Reproductive genomics of the mouse: implications for human fertility and infertility.

Genetic analyses of mammalian gametogenesis and fertility have the potential to inform about two important and interrelated clinical areas: infertility and contraception. Here, we address the genetics and genomics underlying gamete formation, productivity and function in the context of reproductive success in mammalian systems, primarily mouse and human. Although much is known about the specific genes and proteins required for meiotic processes and sperm function, we know relatively little about other gametic determinants of overall fertility, such as regulation of gamete numbers, duration of gamete production, and gamete selection and function in fertilization. As fertility is not a binary trait, attention is now appropriately focused on the oligogenic, quantitative aspects of reproduction. Multiparent mouse populations, created by complex crossing strategies, exhibit genetic diversity similar to human populations and will be valuable resources for genetic discovery, helping to overcome current limitations to our knowledge of mammalian reproductive genetics. Finally, we discuss how what we know about the genomics of reproduction can ultimately be brought to the clinic, informing our concepts of human fertility and infertility, and improving assisted reproductive technologies.

"In Vitro 3d Model of Female Reproductive Tract: An Overview and Future Aspect"

Hormones must be balanced and dynamically controlled for the Female Reproductive Tract (FRT) to function correctly during the menstrual cycle, pregnancy, and delivery. Gamete selection and successful transfer to the uterus, where it implants and pregnancy occurs, is supported by the mucosal epithelial lining of the FRT ovaries, uterus, cervix, fallopian tubes, and vagina. Successful implantation and placentation in humans and other animals rely on complex interactions between the embryo and a receptive female reproductive system.

Embryo production by in vitro fertilization in wild ungulates: progress and perspectives – A Review

Abstract Wild ungulates are of fundamental importance for balancing ecosystems, as well as being the species of economic interest. Increasing concern over the accelerated population reduction of these species has resulted in the development of assisted reproduction techniques, such as in vitro fertilization (IVF), as a tool for conservation and multiplication. In the present scenario, IVF protocols were developed based on the methodologies used for domestic ungulates. Nevertheless, owing to the physiological and reproductive differences among the species, several factors associated with IVF and its relationship with the characteristics of the species of interest require clarification. In vitro conditions for the collection and selection of female and male gametes, oocyte maturation, sperm capacitation, co-incubation of gametes, and embryonic development can influence IVF results. Therefore, the present review considers the main advances in the methodologies already used for wild ungulates, emphasizing the strategies for improving the protocols to obtain better efficiency rates. Additionally, we discuss the conditions of each IVF stage, with emphasis on aspects related to in vitro manipulation and comparability with the protocols for domestic ungulates.

AI, Time-lapse and Biomarkers: What Can We Expect in the Next Decade?

For 40 years we have relied upon morphological assessment of the human embryo for its selection for transfer. With the advent of time-lapse microscopy (TLM), we have been able examine the timings of key developmental events and create algorithms to further advance embryo selection. However, such algorithms do not utilise all available data. Artificial intelligence (AI) can utilise the hundreds of successive images of each embryo as it develops to produce highly predictive rankings. This approach increases the speed of assessment, while decreasing variation typically associated with the subjective analysis of individual embryologists. Therefore, AI represents a means to increase both accuracy and standardisation of embryo selection. In the IVF laboratory, beyond its current function in embryo selection, AI will be used for gamete selection prior to fertilisation, and to increase laboratory function by its integration into Quality Control and Management systems. Although TLM combined with AI holds great potential, it does not quantitate the physiological status of the embryo. Analysis of spent culture medium has revealed that metabolism (glucose uptake and the utilisation of amino acids) of the human blastocyst is related to pregnancy. Currently, analysis of metabolic function by individual embryos requires highly specialised technologies, but with the advent of microfluidics and microfabrication we are entering an era of novel benchtop technologies capable of rapid single embryo analysis. Subsequently, it is envisaged that AI will be used in combination with TLM and the analysis of spent culture medium (to quantitate metabolism and plausibly cell-free DNA), to identify non-invasively the healthiest embryo for transfer.

O-220 Automation and the future of fertility care: An ethical analysis of empowerment-oriented innovation

Abstract Study question What do the anticipated ethical benefits of automation oriented innovations in assisted reproductive technology teach us about the future of ethical assessments of fertility services? Summary answer Benefits like democratization and empowerment to justify disruptive innovation in the fertility field may obscure more fundamental ethical concerns about justice, self-surveillance and reproductive/parenthood ideals. What is known already It is believed that combining robotic components and artificial intelligence may yield an automated ‘lab in a box’ that reduces costs of gamete selection, fertilization, embryo development and genetic testing. Earlier references to ‘fertility labs in a box’ focused on functionality in traditional laboratory setups. Present-day rhetoric instead emphasizes the assumedly democratizing potential, aimed at transforming the fertility sector from reactively treating infertility to proactively managing fertility. Accordingly, the idea is to go after the ‘bigger market’ of preventive management of fertility, to allegedly empower people to reproduce at a time that is most convenient. Study design, size, duration A literature study was performed to inventory how future visions of automated, low-cost and anticipatory fertility management are gaining momentum, not only as marketing efforts of private companies, but also in academic literature among medical professionals and researchers. It was observed how these aspirations are justified with reference to moral values like empowerment and equality. This was critically evaluated against the backdrop of ethical arguments, indicating that beyond apparent benefits there are weighty moral questions. Participants/materials, setting, methods Literature study, conceptual analysis, normative analysis. Main results and the role of chance The anticipated ethical benefits of automated ‘fertility labs in a box’ are couched with high hopes about affordable and democratic fertility services and about empowering individuals to become managers of their own reproductive future. The ethical value of these benefits may seem to resonate with the importance of reproductive autonomy and just access. Yet, it is debatable whether these reproductive technological innovations that are promoted under the flag of empowerment, reproductive autonomy and accessibility will actually have a beneficial impact in terms of these values. It may be questioned how empowering it is to provoke demand for an unproven service that is supposed to vouch for reproductive goals that individuals may, or may not have later in life. More fundamentally, by fixating on the narrow way in which central ethical values like equality, autonomy and empowerment are employed to justify revenue-driven steps towards an automated fertility lab of the future, other crucial questions might be hedged. As will be shown during this presentation, careful ethical analysis can expose that more fundamental questions should be asked about economic constellations, self-surveillance, and fundamental matters pertaining to what ought to be valued, rather than what is valued or desired about human reproduction. Limitations, reasons for caution This is an agenda-setting analysis, and so it is not meant to serve as an exhaustive discussion of these moral concerns. While automated fertility labs are a speculative matter indeed, these perspectives are nonetheless gaining momentum, not only as commercial rhetoric, but also in scientific literature. Wider implications of the findings These findings instigate reflection about (bio)ethical analysis by accentuating the importance of contextual and global elements that may propel or restrain individuals’ reproductive options. This analysis also connects with earlier forms of ‘disruptive innovation’ rhetoric related to egg freezing enterprises as a way to transform infertility treatment into fertility management. Trial registration number N/A

Sex formation in carp and factors influence on its differentiation

The mechanisms that determine and regulate the sex of carp have been discussed in the article. Studies of the mechanisms that determine and regulate sex in fish are of considerable interest from the point of view of the possibility of active exposure such as both on the processes of individual growth and on the possibility of increasing the number of individuals of the sex having economically valuable qualities (growth rate, survival rate, quality and quantity of eggs, etc.). Differentiation underlies morphogenesis and occurs mainly in the process of embryonic development, as well as in postembryonic development and in some organs of the adult organism. The main factor of differentiation is the differences in the cytoplasm of early embryonic cells due to the heterogeneity of the cytoplasm of the egg and the specific infl uence of neighboring cells such as induction. It has been found that both heredity and external factors (temperature and pH of water during incubation, gamete size, feed quality, age selection of producers) influence the sex of carp. When feeding carp brood fish with a low protein diet during their reproduction, females dominated the offspring (62 %), and males dominated the high protein diet (56 %). When reproducing older carp brood fish (10 years or more) males predominated in the offspring, with the selection of middle-aged (7-8 years) males also prevailed, and when selecting young (4-5 years old), females prevailed. Homogeneous selection of gametes, i.e. when fertilizing large-sized eggs with large sperms, significantly more females have been obtained in the offspring, and when using small gametes, males dominated in the offspring. With heterogeneous types of gamete selection, sperm played a crucial role in determining sex.

Fine Mapping of Two Interacting Loci for Transmission Ratio Distortion in Rice (Oryza sativa L.)

Transmission ratio distortion (TRD) denotes the observed allelic or genotypic frequency deviation from the expected Mendelian segregation ratios in the offspring of a heterozygote. TRD can severely hamper gene flow between and within rice species. Here, we report the fine mapping and characterization of two loci (TRD4.1 and TRD4.2) for TRD using large F2 segregating populations, which are derived from rice chromosome segment substitution lines, each containing a particular genomic segment introduced from the japonica cultivar Nipponbare (NIP) into the indica cultivar Zhenshan (ZS97). The two loci exhibited a preferential transmission of ZS97 alleles in the derived progeny. Reciprocal crossing experiments using near-isogenic lines harboring three different alleles at TRD4.1 suggest that the gene causes male gametic selection. Moreover, the transmission bias of TRD4.2 was diminished in heterozygotes when they carried homozygous TRD4.1ZS97. This indicates an epistatic interaction between these two loci. TRD4.2 was mapped into a 35-kb region encompassing one candidate gene that is specifically expressed in the reproductive organs in rice. These findings broaden the understanding of the genetic mechanisms of TRD and offer an approach to overcome the barrier of gene flow between the subspecies in rice, thus facilitating rice improvement by introgression breeding.

DNA damage in preimplantation embryos and gametes: specification, clinical relevance and repair strategies.

BACKGROUNDDNA damage is a hazard that affects all cells of the body. DNA-damage repair (DDR) mechanisms are in place to repair damage and restore cellular function, as are other damage-induced processes such as apoptosis, autophagy and senescence. The resilience of germ cells and embryos in response to DNA damage is less well studied compared with other cell types. Given that recent studies have described links between embryonic handling techniques and an increased likelihood of disease in post-natal life, an update is needed to summarize the sources of DNA damage in embryos and their capacity to repair it. In addition, numerous recent publications have detailed novel techniques for detecting and repairing DNA damage in embryos. This information is of interest to medical or scientific personnel who wish to obtain undamaged embryos for use in offspring generation by ART.OBJECTIVE AND RATIONALEThis review aims to thoroughly discuss sources of DNA damage in male and female gametes and preimplantation embryos. Special consideration is given to current knowledge and limits in DNA damage detection and screening strategies. Finally, obstacles and future perspectives in clinical diagnosis and treatment (repair) of DNA damaged embryos are discussed.SEARCH METHODSUsing PubMed and Google Scholar until May 2021, a comprehensive search for peer-reviewed original English-language articles was carried out using keywords relevant to the topic with no limits placed on time. Keywords included ‘DNA damage repair’, ‘gametes’, ‘sperm’, ‘oocyte’, ‘zygote’, ‘blastocyst’ and ‘embryo’. References from retrieved articles were also used to obtain additional articles. Literature on the sources and consequences of DNA damage on germ cells and embryos was also searched. Additional papers cited by primary references were included. Results from our own studies were included where relevant.OUTCOMESDNA damage in gametes and embryos can differ greatly based on the source and severity. This damage affects the development of the embryo and can lead to long-term health effects on offspring. DDR mechanisms can repair damage to a certain extent, but the factors that play a role in this process are numerous and altogether not well characterized. In this review, we describe the multifactorial origin of DNA damage in male and female gametes and in the embryo, and suggest screening strategies for the selection of healthy gametes and embryos. Furthermore, possible therapeutic solutions to decrease the frequency of DNA damaged gametes and embryos and eventually to repair DNA and increase mitochondrial quality in embryos before their implantation is discussed.WIDER IMPLICATIONSUnderstanding DNA damage in gametes and embryos is essential for the improvement of techniques that could enhance embryo implantation and pregnancy success. While our knowledge about DNA damage factors and regulatory mechanisms in cells has advanced greatly, the number of feasible practical techniques to avoid or repair damaged embryos remains scarce. Our intention is therefore to focus on strategies to obtain embryos with as little DNA damage as possible, which will impact reproductive biology research with particular significance for reproductive clinicians and embryologists.

Male Age and Progressive Sperm Motility Are Critical Factors Affecting Embryological and Clinical Outcomes in Oocyte Donor ICSI Cycles.

This retrospective cohort study aimed to explore whether paternal age and semen quality parameters affect the embryological and clinical outcomes of ICSI with oocyte donation. A total of 339 oocyte donation (OD)-ICSI cycles were categorized into four groups according to the semen parameter profiles of the male counterparts: normozoospermia (NS, n = 184), oligozoospermia (OS, n = 41), asthenozoospermia (AS, n = 50), and oligoasthenozoospermia (OAS, n = 64). The effect of age, total sperm count, and progressive motility was separately analyzed for reproductive outcomes and compared between the study groups: fertilization, blastulation, and top-quality embryo rate, biochemical and clinical pregnancy, live birth, and miscarriage. A negative correlation between male age and fertilization rate was observed (rs = - 0.23, p < 0.0001), while male age was a significant factor for biochemical pregnancy (p = 0.0002), clinical pregnancy (p = 0.0017), and live birth (p = 0.0038). Reduced total sperm count and lowered progressive motility led to poorer fertilization rates (rs = 0.19 and 0.35, respectively, p < 0.0001) and affected embryo quality (rs = 0.13, p = 0.02, and rs = 0.22, p < 0.0001, respectively). OD-ICSI cycles with asthenozoospermia had significantly lowered success rates in biochemical pregnancy, clinical pregnancy, and live birth (p < 0.05). Our study demonstrated that both advanced male age and reduced progressive motility of spermatozoa exert a significant negative influence on the outcome of assisted reproduction, even in controlled procedures with gamete selection and optimization such as in OD-ICSI. Improvement in treatment strategies and male fertility evaluation requires incorporation of such evidence to obtain better prognosis towards personalized management.

Some results of the study of alfalfa and meadow clover samples created by biotechnology methods

The conditions for creating alfalfa samples MN-2 (from the Selena variety) and P-67 (from the Lugovaya variety) with increased resistance to Fusarium pathogens using the method of gamete selection are described. The method is based on the selection of gametes in vivo under the influence of a selective factor (culture filtrate) introduced into the generative organs at the early stages of their development using vacuum infiltration. The method was developed in the biotechnology department of the V.N. V.R. Williams. The accessions are included in the breeding process and are currently the accessory varieties. In order to identify differences at the genetic level between the created varieties and the original forms, a comparative analysis was carried out using 2 types of molecular markers based on the PCR method. DNA polymorphism was detected using SRAP primers, which may indicate a change in the structure of genes associated with economic and biological traits. Research is ongoing. When growing under the conditions of a selection and greenhouse complex of acid-tolerant plants of meadow clover, created using cellular technologies in vitro, the infestation by powdery mildew of 120 acid-tolerant plants was studied. No signs of damage were found in 10% of plants. The largest number of affected plants (36.7%) had a score of 3. It was found that a high infestation with powdery mildew (scores 4 and 5) significantly reduces the number of inflorescences in the bush to 83.4 and 75.7%, respectively. Therefore, in further studies to create a population of acid-tolerant plants, the genotypes of meadow clover were used without signs and with a low score of powdery mildew damage.

Interaction Between Hyaluronic Acid Semi‐Interpenetrated Hydrogel with Bull Spermatozoa: Studies of Sperm Attachment–Release and Sperm Quality

AbstractThe study of living systems in contact with biocompatible synthetic hydrogels is developing. The authors’ group is the first to propose use of polymeric materials to accomplish sperm selection process by attachment of bull sperm to hydrogel surfaces, this being a crucial step for successful assisted reproductive techniques (ARTs). Surfaces based on poly(N‐isopropylacrylamide) hydrogels (PNIPAM) and ionic and neutral copolymers are synthetized. Their physicochemical properties in aqueous and culture medium are related to the percentage of attachment and subsequent release of bull spermatozoa from the hydrogel surface. High attaching capacity (30–45%) of sperm on cationic and neutral surfaces is mainly observed, however, sperm detachment from the hydrogel using traditional induction processes (i.e., sperm capacitation) is not significant. Therefore, PNIPAM‐co‐20%‐N‐Tris(hydroxymethyl)methyl acrylamide (PNIPAM‐HMA) hydrogel surface is semi‐interpenetrated with hyaluronic acid (HA). In this case, 50% of spermatozoa are attached to PNIPAM‐HMA‐HA hydrogel and after treatment with hyaluronidase, 47% of them are released. Collected sperm show acceptable characteristics of progressive motility (70% with score 4 for vigor), high viability, and cytoplasmic membrane integrity. Noteworthy, the study of the interaction of hydrogel surface/spermatozoa can be extended to human and other mammalian species, in order to provide advanced alternatives for gamete selection for ARTs.