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Annals of the Academy of Medicine,... Jan 2024Female fecundity decreases significantly after the age of 32, and rapidly so after age 37. There is no treatment to prevent this decline. Furthermore, globally, women... (Review)
Review
INTRODUCTION
Female fecundity decreases significantly after the age of 32, and rapidly so after age 37. There is no treatment to prevent this decline. Furthermore, globally, women are getting married later and the age at which they have their first child is increasing. As of July 2023, elective egg freezing (EEF) or oocyte cryopreservation (OC) for age-related fertility decline, commenced in Singapore. With medical advancements in OC, EEF is no longer considered experimental. The aim of this review is to examine the existing literature around EEF with regard to reproductive outcomes and its safety, to better guide clinicians in counselling young single women.
METHOD
Published studies were examined to increase understanding on optimal age for EEF, ideal number of oocytes for a live birth, recommended OC protocols, cryopreservation techniques affecting thaw survival or fertilisation, oocyte storage and pregnancy risks.
RESULTS
Models predict that EEF should be performed at age <37 years and to achieve a 70% chance of live birth, women would need 14, 15 and 26 mature oocytes at ages 30-34, 35-37 and >38 years, respec-tively. An antagonist stimulation protocol with an agonist trigger would minimise ovarian hyper-stimulation syndrome and duration of stimulation without affecting outcomes. Oocyte vitrification in comparison to slow freezing increases thaw survival, fertilisation and clinical pregnancy rates. No increased risks exist for the woman, future pregnancy or child when compared with conventional IVF.
CONCLUSION
EEF is a viable option for single women desiring fertility preservation. Financial costs are significant, but returns are worthwhile if oocytes are utilised.
Topics: Humans; Cryopreservation; Female; Oocytes; Pregnancy; Fertility Preservation; Adult; Pregnancy Rate; Singapore; Vitrification; Live Birth; Ovulation Induction; Age Factors
PubMed: 38920213
DOI: 10.47102/annals-acadmedsg.2023226 -
Annals of the Academy of Medicine,... Jan 2024
Topics: Humans; Cryopreservation; Female; Fertility Preservation; Oocytes; Optimism; Hope
PubMed: 38920209
DOI: 10.47102/annals-acadmedsg.2023428 -
BMC Veterinary Research Jun 2024In vitro embryo production is a highly demanded reproductive technology in horses, which requires the recovery (in vivo or post-mortem) and in vitro maturation (IVM) of...
BACKGROUND
In vitro embryo production is a highly demanded reproductive technology in horses, which requires the recovery (in vivo or post-mortem) and in vitro maturation (IVM) of oocytes. Oocytes subjected to IVM exhibit poor developmental competence compared to their in vivo counterparts, being this related to a suboptimal composition of commercial maturation media. The objective of this work was to study the effect of different concentrations of secretome obtained from equine preovulatory follicular fluid (FF) on cumulus-oocyte complexes (COCs) during IVM. COCs retrieved in vivo by ovum pick up (OPU) or post-mortem from a slaughterhouse (SLA) were subjected to IVM in the presence or absence of secretome (Control: 0 µg/ml, S20: 20 µg/ml or S40: 40 µg/ml). After IVM, the metabolome of the medium used for oocyte maturation prior (Pre-IVM) and after IVM (Post-IVM), COCs mRNA expression, and oocyte meiotic competence were analysed.
RESULTS
IVM leads to lactic acid production and an acetic acid consumption in COCs obtained from OPU and SLA. However, glucose consumption after IVM was higher in COCs from OPU when S40 was added (Control Pre-IVM vs. S40 Post-IVM: 117.24 ± 7.72 vs. 82.69 ± 4.24; Mean µM ± SEM; p < 0.05), while this was not observed in COCs from SLA. Likewise, secretome enhanced uptake of threonine (Control Pre-IVM vs. S20 Post-IVM vs. S40 Post-IVM: 4.93 ± 0.33 vs. 3.04 ± 0.25 vs. 2.84 ± 0.27; Mean µM ± SEM; p < 0.05) in COCs recovered by OPU. Regarding the relative mRNA expression of candidate genes related to metabolism, Lactate dehydrogenase A (LDHA) expression was significantly downregulated when secretome was added during IVM at 20-40 µg/ml in OPU-derived COCs (Control vs. S20 vs. S40: 1.77 ± 0.14 vs. 1 ± 0.25 vs. 1.23 ± 0.14; fold change ± SEM; p < 0.05), but not in SLA COCs.
CONCLUSIONS
The addition of secretome during in vitro maturation (IVM) affects the gene expression of LDHA, glucose metabolism, and amino acid turnover in equine cumulus-oocyte complexes (COCs), with diverging outcomes observed between COCs retrieved using ovum pick up (OPU) and slaughterhouse-derived COCs (SLA).
Topics: Animals; Horses; Oocytes; Follicular Fluid; In Vitro Oocyte Maturation Techniques; Cumulus Cells; Female; Culture Media; Secretome
PubMed: 38918770
DOI: 10.1186/s12917-024-04129-1 -
Nature Communications Jun 2024During human embryonic development, early cleavage-stage embryos are more susceptible to errors. Studies have shown that many problems occur during the first mitosis,...
During human embryonic development, early cleavage-stage embryos are more susceptible to errors. Studies have shown that many problems occur during the first mitosis, such as direct cleavage, chromosome segregation errors, and multinucleation. However, the mechanisms whereby these errors occur during the first mitosis in human embryos remain unknown. To clarify this aspect, in the present study, we image discarded living human two-pronuclear stage zygotes using fluorescent labeling and confocal microscopy without microinjection of DNA or mRNA and investigate the association between spindle shape and nuclear abnormality during the first mitosis. We observe that the first mitotic spindles vary, and low-aspect-ratio-shaped spindles tend to lead to the formation of multiple nuclei at the 2-cell stage. Moreover, we observe defocusing poles in many of the first mitotic spindles, which are strongly associated with multinucleation. Additionally, we show that differences in the positions of the centrosomes cause spindle abnormality in the first mitosis. Furthermore, many multinuclei are modified to form mononuclei after the second mitosis because the occurrence of pole defocusing is firmly reduced. Our study will contribute markedly to research on the occurrence of mitotic errors during the early cleavage of human embryos.
Topics: Humans; Spindle Apparatus; Mitosis; Cell Nucleus; Zygote; Embryo, Mammalian; Microscopy, Confocal; Centrosome; Embryonic Development; Female
PubMed: 38918406
DOI: 10.1038/s41467-024-49815-8 -
Proceedings. Biological Sciences Jun 2024Externally laid eggs are often responsive to environmental cues; however, it is unclear how such plasticity evolves. In Trinidad, the killifish () is found in...
Externally laid eggs are often responsive to environmental cues; however, it is unclear how such plasticity evolves. In Trinidad, the killifish () is found in communities with and without predators. Here, killifish inhabit shallower, ephemeral habitats in sites with predators. Such shifts may increase the exposure of eggs to air and lead to possible desiccation. We compared egg-hatching plasticity between communities by rearing eggs terrestrially on peat moss or in water. The timing of hatching did not differ between communities when eggs were reared in water. Eggs from sites with predators responded to terrestrial incubation by hatching significantly earlier compared with water-reared eggs. These responses were weaker in sites with no predators. Such divergent trends show that the presence of predators is associated with evolutionary shifts in hatching plasticity. Our results provide evidence for local adaptation in embryonic plasticity at the population scale.
Topics: Animals; Fundulidae; Trinidad and Tobago; Biological Evolution; Ecosystem; Ovum; Adaptation, Physiological; Predatory Behavior; Killifishes
PubMed: 38917866
DOI: 10.1098/rspb.2024.0083 -
Proceedings of the National Academy of... Jul 2024A dispersed cytoplasmic distribution of mitochondria is a hallmark of normal cellular organization. Here, we have utilized the expression of exogenous in mouse oocytes...
A dispersed cytoplasmic distribution of mitochondria is a hallmark of normal cellular organization. Here, we have utilized the expression of exogenous in mouse oocytes and embryos to disrupt the dispersed distribution of mitochondria by driving them into a large cytoplasmic aggregate. Our findings reveal that aggregated mitochondria have minimal impact on asymmetric meiotic cell divisions of the oocyte. In contrast, aggregated mitochondria during the first mitotic division result in daughter cells with unequal sizes and increased micronuclei. Further, in two-cell embryos, microtubule-mediated centering properties of the mitochondrial aggregate prevent nuclear centration, distort nuclear shape, and inhibit DNA synthesis and the onset of embryonic transcription. These findings demonstrate the motor protein-mediated distribution of mitochondria throughout the cytoplasm is highly regulated and is an essential feature of cytoplasmic organization to ensure optimal cell function.
Topics: Animals; Mitochondria; Blastocyst; Mice; Cell Nucleus; Oocytes; Female; Embryonic Development; Microtubules; Mitosis; Meiosis
PubMed: 38917013
DOI: 10.1073/pnas.2317316121 -
BMC Genomics Jun 2024Although, oocytes from prepubertal donors are known to be less developmentally competent than those from adult donors it does not restrain their ability to produce...
BACKGROUND
Although, oocytes from prepubertal donors are known to be less developmentally competent than those from adult donors it does not restrain their ability to produce full-term pregnancies. The transcriptomic profile of embryos could be used as a predictor for embryo's individual developmental competence. The aim of the study was to compare transcriptomic profile of blastocysts derived from prepubertal and pubertal heifers oocytes. Bovine cumulus-oocyte complexes (COCs) were obtained by ovum pick- up method from prepubertal and pubertal heifers. After in vitro maturation COCs were fertilized and cultured to the blastocyst stage. Total RNA was isolated from both groups of blastocysts and RNA-seq was performed. Gene ontology analysis was performed by DAVID (Database for Annotation, Visualization and Integrated Discovery).
RESULTS
A higher average blastocyst rate was obtained in the pubertal than in the pre-pubertal group. There were no differences in the quality of blastocysts between the examined groups. We identified 436 differentially expressed genes (DEGs) between blastocysts derived from researched groups, of which 247 DEGs were downregulated in blastocysts derived from pubertal compared to prepubertal heifers oocytes, and 189 DEGs were upregulated. The genes involved in mitochondrial function, including oxidative phosphorylation (OXPHOS) were found to be different in studied groups using Kyoto Encyclopedia of Genes (KEGG) pathway analysis and 8 of those DEGs were upregulated and 1 was downregulated in blastocysts derived from pubertal compared to prepubertal heifers oocytes. DEGs associated with mitochondrial function were found: ATP synthases (ATP5MF-ATP synthase membrane subunit f, ATP5PD- ATP synthase peripheral stalk subunit d, ATP12A- ATPase H+/K + transporting non-gastric alpha2 subunit), NADH dehydrogenases (NDUFS3- NADH: ubiquinone oxidoreductase subunit core subunit S3, NDUFA13- NADH: ubiquinone oxidoreductase subunit A13, NDUFA3- NADH: ubiquinone oxidoreductase subunit A3), cytochrome c oxidase (COX17), cytochrome c somatic (CYCS) and ubiquinol cytochrome c reductase core protein 1 (UQCRC1). We found lower number of apoptotic cells in blastocysts derived from oocytes collected from prepubertal than those obtained from pubertal donors.
CONCLUSIONS
Despite decreased expression of genes associated with OXPHOS pathway in blastocysts from prepubertal heifers oocytes, the increased level of ATP12A together with the lower number of apoptotic cells in these blastocysts might support their survival after transfer.
Topics: Animals; Cattle; Oxidative Phosphorylation; Female; Gene Expression Profiling; Blastocyst; Transcriptome; Sexual Maturation; Oocytes; Gene Expression Regulation, Developmental; Fertilization in Vitro
PubMed: 38914933
DOI: 10.1186/s12864-024-10532-7 -
Scientific Reports Jun 2024Having been successfully bred in semi-intensive and intensive aquaculture systems, oval squids of the Sepioteuthis lessoniana species complex are emerging as promising...
Having been successfully bred in semi-intensive and intensive aquaculture systems, oval squids of the Sepioteuthis lessoniana species complex are emerging as promising candidates for research and industry. Nevertheless, information about pathogens and diseases that may affect squid aquaculture remains sparse. In this study, we identify new parasitic copepod species that causes squid mortality and decreases squid hatching rates, and we also offer a solution to eliminate the pathogen during incubation of squid eggs. The newly discovered copepod Ikanecator primus gen. et sp. nov. was identified on oval squid eggs for the first time using both morphological and molecular diagnostic markers. In the genomes of the copepod and associated microbiome, we identified multiple genes for enzymes involved in cephalopod eggshell degradation in genomes of the copepod and associated microbiome. Furthermore, we conducted experiments to assess efficacy of peracetic acid in inhibiting the I. primus gen. et sp. nov. both in vitro and in vivo using immersion treatment. We established that a 2-min exposure to a concentration of 250 μl/L of peracetic acid containing product (PAA-product; 35 mg/L PAA and 15 mg/L HO) inhibited the development of nauplii in vitro. All parasites exposed to a concentration of 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L HO) were eliminated within two minutes. On top of this, the immersion treatment with 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L HO) improved survival of squid embryos and increased size of squid hatchlings compared with control and the immersion treatment with 125 μl/L of PAA-product (17.5 mg/L PAA and 7.5 mg/L HO) and the immersion treatment with 250 μl/L of PAA-product (35 mg/L PAA and 15 mg/L HO). These findings suggest that PAA holds a great potential as inhibitor and controller of parasitic copepod infections and for overall health management in cephalopod culture.
Topics: Animals; Decapodiformes; Copepoda; Peracetic Acid; Ovum; Aquaculture
PubMed: 38914681
DOI: 10.1038/s41598-024-65290-z -
Nature Communications Jun 2024Cytoplasmic polyadenylation plays a vital role in gametogenesis; however, the participating enzymes and substrates in mammals remain unclear. Using knockout and knock-in...
Cytoplasmic polyadenylation plays a vital role in gametogenesis; however, the participating enzymes and substrates in mammals remain unclear. Using knockout and knock-in mouse models, we describe the essential role of four TENT5 poly(A) polymerases in mouse fertility and gametogenesis. TENT5B and TENT5C play crucial yet redundant roles in oogenesis, with the double knockout of both genes leading to oocyte degeneration. Additionally, TENT5B-GFP knock-in females display a gain-of-function infertility effect, with multiple chromosomal aberrations in ovulated oocytes. TENT5C and TENT5D both regulate different stages of spermatogenesis, as shown by the sterility in males following the knockout of either gene. Finally, Tent5a knockout substantially lowers fertility, although the underlying mechanism is not directly related to gametogenesis. Through direct RNA sequencing, we discovered that TENT5s polyadenylate mRNAs encoding endoplasmic reticulum-targeted proteins essential for gametogenesis. Sequence motif analysis and reporter mRNA assays reveal that the presence of an endoplasmic reticulum-leader sequence represents the primary determinant of TENT5-mediated regulation.
Topics: Animals; Female; Male; Polyadenylation; RNA, Messenger; Mice; Mice, Knockout; Spermatogenesis; Gametogenesis; Oogenesis; Polynucleotide Adenylyltransferase; Oocytes; Fertility; Mice, Inbred C57BL
PubMed: 38909026
DOI: 10.1038/s41467-024-49479-4 -
Scientific Data Jun 2024Acrossocheilus fasciatus is a stream-dwelling fish species of the Barbinae subfamily. It is valued for its colorfully striped appearance and delicious meat. This species...
Acrossocheilus fasciatus is a stream-dwelling fish species of the Barbinae subfamily. It is valued for its colorfully striped appearance and delicious meat. This species is also characterized by apparent sexual dimorphism and toxic ovum. Biology and aquaculture researches of A. fasciatus are hindered by the lack of a high-quality reference genome. Here, we report chromosome-level genome assemblies of the male and female A. fasciatus. The HiFi-only genome assemblies for both female and male individuals were 899.13 Mb (N50 length of 32.58 Mb) and 885.68 Mb (N50 length of 33.06 Mb), respectively. Notably, a substantial proportion of the assembled sequences, accounting for 96.15% and 98.35% for female and male genomes, respectively, were successfully anchored onto 25 chromosomes utilizing Hi-C data. We annotated the female assembly as a reference genome and identified a total of 400.62 Mb (44.56%) repetitive sequences, 27,392 protein-coding genes, and 35,869 ncRNAs. The high-quality male and female reference genomes will provide genomic resources for developing sex-specific molecular markers, inform single-sex breeding, and elucidate genetic mechanisms of sexual dimorphism.
Topics: Animals; Female; Male; Genome; Sex Characteristics; Chromosomes; Cyprinidae
PubMed: 38906919
DOI: 10.1038/s41597-024-03504-9