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Plant Reproduction Jun 2024The DNA methylation status at an epigenetic quantitative trait locus in the Arabidopsis chromosome 2 is linked to the formation of apomictic-like endosperms. Seed...
The DNA methylation status at an epigenetic quantitative trait locus in the Arabidopsis chromosome 2 is linked to the formation of apomictic-like endosperms. Seed development in most angiosperms is coupled to fertilization of the maternal gametes by two sperm cells. However, apomictic species can reproduce asexually via seeds. This trait is of great agricultural interest, as it would fix complex genotypes and allow for pollen-independent seed production. However, engineering full apomixis requires three independent processes: apomeiosis, parthenogenesis and autonomous endosperm development. While the first two have been successfully engineered in some crops, the formation of autonomous endosperms remains a challenge. Although it is known that this trait is under epigenetic control, such as of DNA methylation, the underlying mechanisms remain mostly undiscovered. Here, using epigenetic recombinant inbred lines, we identified an epigenetic quantitative trait locus in the Arabidopsis chromosome 2, which correlates with permissiveness for the formation of asexual seeds: hypomethylation at this genomic region allows the formation of larger autonomous endosperms. Importantly, the methylation at this locus only correlates with asexual seed size, and not to the size of sexual seeds or that of other organs. With this, we aim to show that screening for epialleles is a promising strategy to uncover loci underlying relevant traits and could pave the way to identifying genes necessary for the engineering of apomixis.
PubMed: 38836892
DOI: 10.1007/s00497-024-00504-y -
Current Biology : CB Jun 2024The Wolbachia strain that infects the parasitoid wasp Encarsia formosa induces female-producing parthenogenesis. A new study shows that a Wolbachia-encoded gene has...
The Wolbachia strain that infects the parasitoid wasp Encarsia formosa induces female-producing parthenogenesis. A new study shows that a Wolbachia-encoded gene has replaced the use of the ancestral wasp homologue that normally controls sexual reproduction, resulting in parthenogenesis.
Topics: Wolbachia; Parthenogenesis; Animals; Wasps; Female; Reproduction
PubMed: 38834030
DOI: 10.1016/j.cub.2024.04.076 -
Reproduction in Domestic Animals =... Jun 2024This study examines the impact of Notoginsenoside R1 (NGR1), a compound from Panax notoginseng, on the maturation of porcine oocytes and their embryonic development,...
This study examines the impact of Notoginsenoside R1 (NGR1), a compound from Panax notoginseng, on the maturation of porcine oocytes and their embryonic development, focusing on its effects on antioxidant levels and mitochondrial function. This study demonstrates that supplementing in vitro maturation (IVM) medium with NGR1 significantly enhances several biochemical parameters. These include elevated levels of glutathione (GSH), nuclear factor erythrocyte 2-related factor 2 (NRF2) and mRNA expression of catalase (CAT) and GPX. Concurrently, we observed a decrease in reactive oxygen species (ROS) levels and an increase in JC-1 immunofluorescence, mitochondrial distribution, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) and nuclear NRF2 mRNA levels. Additionally, there was an increase in ATP production and lipid droplets (LDs) immunofluorescence. These biochemical improvements correlate with enhanced embryonic outcomes, including a higher blastocyst rate, increased total cell count, enhanced proliferative capacity and elevated octamer-binding transcription factor 4 (Oct4) and superoxide dismutase 2 (Sod2) gene expression. Furthermore, NGR1 supplementation resulted in decreased apoptosis, reduced caspase 3 (Cas3) and BCL2-Associated X (Bax) mRNA levels and decreased glucose-regulated protein 78 kD (GRP78) immunofluorescence in porcine oocytes undergoing in vitro maturation. These findings suggest that NGR1 plays a crucial role in promoting porcine oocyte maturation and subsequent embryonic development by providing antioxidant levels and mitochondrial protection.
Topics: Animals; Antioxidants; Ginsenosides; In Vitro Oocyte Maturation Techniques; Mitochondria; Embryonic Development; Oocytes; Female; Swine; Reactive Oxygen Species; Embryo Culture Techniques
PubMed: 38828566
DOI: 10.1111/rda.14631 -
Journal of Integrative Plant Biology May 2024Parthenogenesis, the development of unfertilized egg cells into embryos, is a key component of apomixis. AtBBM (BABY BOOM), a crucial regulator of embryogenesis in...
Parthenogenesis, the development of unfertilized egg cells into embryos, is a key component of apomixis. AtBBM (BABY BOOM), a crucial regulator of embryogenesis in Arabidopsis, possesses the capacity to shift nutritional growth toward reproductive growth. However, the mechanisms underlying AtBBM-induced parthenogenesis remain largely unexplored in dicot plants. Our findings revealed that in order to uphold the order of sexual reproduction, the embryo-specific promoter activity of AtBBM as well as repressors that inhibit its expression in egg cells combine to limiting its ability to induce parthenogenesis. Notably, AtRKD5, a RWP-RK domain-containing (RKD) transcription factor, binds to the 3' end of AtBBM and is identified as one of the inhibitory factors for AtBBM expression in the egg cell. In the atrkd5 mutant, we successfully achieved enhanced ectopic expression of AtBBM in egg cells, resulting in the generation of haploid offspring via parthenogenesis at a rate of 0.28%. Furthermore, by introducing chimeric Arabidopsis and rice BBM genes into the egg cell, we achieved a significant 4.6-fold enhancement in haploid induction through the atdmp8/9 mutant. These findings lay a strong foundation for further exploration of the BBM-mediated parthenogenesis mechanism and the improvement of haploid breeding efficiency mediated by the dmp8/9 mutant.
PubMed: 38818961
DOI: 10.1111/jipb.13678 -
Animal Reproduction Science Jul 2024Mammalian oocyte activation is a critical process occurring post-gamete fusion, marked by a sequence of cellular events initiated by an upsurge in intracellular Ca. This... (Review)
Review
Mammalian oocyte activation is a critical process occurring post-gamete fusion, marked by a sequence of cellular events initiated by an upsurge in intracellular Ca. This surge in calcium orchestrates the activation/deactivation of specific kinases, leading to the subsequent inactivation of MPF and MAPK activities, alongside PKC activation. Despite various attempts to induce artificial activation using distinct chemical compounds as Ca inducers and/or Ca-independent agents, the outcomes have proven suboptimal. Notably, incomplete suppression of MPF and MAPK activities persists, necessitating a combination of different agents for enhanced efficiency. Moreover, the inherent specificity of activation methods for each species precludes straightforward extrapolation between them. Consequently, optimization of protocols for each species and for each technique, such as PA, ICSI, and SCNT, is required. Despite recent strides in camelid biotechnologies, the field has seen little advancement in chemical activation methods. Only a limited number of chemical agents have been explored, and the effects of many remain unknown. In ICSI, despite obtaining blastocysts with different chemical compounds that induce Ca and calcium-independent increases, viable offspring have not been obtained. However, SCNT has exhibited varying outcomes, successfully yielding viable offspring with a reduced number of chemical activators. This article comprehensively reviews the current understanding of the physiological activation of oocytes and the molecular mechanisms underlying chemical activation in mammals. The aim is to transfer and apply this knowledge to camelid reproductive biotechnologies, with emphasis on chemical activation in PA, ICSI, and SCNT.
Topics: Animals; Oocytes; Female; Camelidae; Nuclear Transfer Techniques
PubMed: 38805838
DOI: 10.1016/j.anireprosci.2024.107499 -
Theriogenology Sep 2024The in vitro maturation (IVM) quality of oocytes is directly related to the subsequent developmental potential of embryos and a fundamental of in vitro embryo...
The in vitro maturation (IVM) quality of oocytes is directly related to the subsequent developmental potential of embryos and a fundamental of in vitro embryo production. However, conventional IVM methods fail to maintain the gap-junction intercellular communication (GJIC) between cumulus-oocyte complexes (COCs), which leads to insufficient oocyte maturation. Herein, we investigated the effects of three different three-dimensional (3D) culture methods on oocyte development in vitro, optimized of the alginate-hydrogel embedding method, and assessed the effects of the alginate-hydrogel embedding method on subsequent embryonic developmental potential of oocytes after IVM and parthenogenetic activation (PA). The results showed that Matrigel embedding and alginate-hydrogel embedding benefited the embryonic developmental potential of oocytes after IVM and PA. With the further optimization of alginate-hydrogel embedding, including crosslinking and decrosslinking of parameters, we established a 3D culture system that can significantly increase oocyte maturation and the blastocyst rate of embryos after PA (27.2 ± 1.5 vs 36.7 ± 2.8, P < 0.05). This 3D culture system produced oocytes with markedly increased mitochondrial intensity and membrane potential, which reduced the abnormalities of spindle formation and cortical granule distribution. The alginate-hydrogel embedding system can also remarkably enhance the GJIC between COCs. In summary, based on alginate-hydrogel embedding, we established a 3D culture system that can improve the IVM quality of porcine oocytes, possibly by enhancing GJIC.
Topics: Animals; In Vitro Oocyte Maturation Techniques; Alginates; Oocytes; Swine; Hydrogels; Cell Culture Techniques, Three Dimensional; Glucuronic Acid; Parthenogenesis; Hexuronic Acids; Female; Embryo Culture Techniques
PubMed: 38788627
DOI: 10.1016/j.theriogenology.2024.05.031 -
Theriogenology Sep 2024Autophagy is essential for oocyte maturation and preimplantation embryo development. ATG4C, a member of the ATG4 family, plays a crucial role in the autophagy process....
Autophagy is essential for oocyte maturation and preimplantation embryo development. ATG4C, a member of the ATG4 family, plays a crucial role in the autophagy process. The effect of ATG4C on the early embryonic development in pig has not been studied. In this study, the expression patterns of ATG4C were explored using qRT-PCR and immunofluorescence staining. Different concentrations of serum were added to in vitro maturation (IVM) medium to investigate its effects on oocyte maturation and embryonic development. Finally, the developmental potential of parthenogenetic embryos was detected by downregulating ATG4C in MII stage oocytes under 0 % serum condition. The results revealed that ATG4C was highly expressed in porcine oocytes matured in vitro and in parthenogenetic embryos. Compared with the 10 % serum group, the cumulus cell expansion, first polar body (PB1) extrusion rate, and subsequent developmental competence of embryos were reduced in the 0 % and 5 % serum groups. The mRNA levels of LC3, ATG5, BECLIN1, TFAM, PGC1α, and PINK1 were significantly increased (P < 0.05) in the 0 % serum group. ATG4C was significantly upregulated in the embryos at the 1-cell, 2-cell, 8-cell, and 16-cell stages in the 0 % serum group (P < 0.05). Compared with the negative control group, downregulation of ATG4C significantly decreased the 4-cell, 8-cell, and blastocyst rates (P < 0.05), and the expression of genes related to autophagy, mitochondria, and zygotic genome activation (ZGA) was significantly decreased (P < 0.05). The relative fluorescence intensity of LC3 and mitochondrial content in the ATG4C siRNA group was significantly reduced (P < 0.05). Collectively, the results indicate that ATG4C is highly expressed in porcine oocytes matured in vitro and in early embryos, and inhibition of ATG4C effects embryonic developmental competence by decreasing autophagy, mitochondrial content, and ZGA under serum-free condition.
Topics: Animals; Swine; Oocytes; Embryonic Development; In Vitro Oocyte Maturation Techniques; Gene Expression Regulation, Developmental; Autophagy-Related Proteins; Embryo Culture Techniques; Female; Autophagy; Parthenogenesis
PubMed: 38781849
DOI: 10.1016/j.theriogenology.2024.05.029 -
Proceedings. Biological Sciences May 2024In social insect colonies, selfish behaviour due to intracolonial conflict among members can result in colony-level costs despite close relatedness. In certain termite...
In social insect colonies, selfish behaviour due to intracolonial conflict among members can result in colony-level costs despite close relatedness. In certain termite species, queens use asexual reproduction for within-colony queen succession but rely on sexual reproduction for worker and alate production, resulting in multiple half-clones of a single primary queen competing for personal reproduction. Our study demonstrates that competition over asexual queen succession among different clone types leads to the overproduction of parthenogenetic offspring, resulting in the production of dysfunctional parthenogenetic alates. By genotyping the queens of 23 field colonies of , we found that clone variation in the queen population reduces as colonies develop. Field sampling of alates and primary reproductives of incipient colonies showed that overproduced parthenogenetic offspring develop into alates that have significantly smaller body sizes and much lower survivorship than sexually produced alates. Our results indicate that while the production of earlier and more parthenogenetic eggs is advantageous for winning the competition for personal reproduction, it comes at a great cost to the colony. Thus, this study highlights the evolutionary interplay between individual-level and colony-level selection on parthenogenesis by queens.
Topics: Animals; Parthenogenesis; Isoptera; Female; Reproduction; Social Behavior
PubMed: 38772420
DOI: 10.1098/rspb.2023.2711 -
American Journal of Botany May 2024Apomixis in ferns is relatively common and obligatory. Sterile hybrids may restore fertility via apomixis at a cost of long-term genetic stagnation. In this study, we...
PREMISE
Apomixis in ferns is relatively common and obligatory. Sterile hybrids may restore fertility via apomixis at a cost of long-term genetic stagnation. In this study, we outlined apomixis as a possible temporary phase leading to sexuality and analyzed factors relating to transitioning to and away from apomixis, such as unreduced and reduced spore formation in apomict and apo-sex hybrid ferns.
METHODS
We analyzed the genome size of 15 fern species or hybrids ("taxa") via flow cytometry. The number of reduced and unreduced gametophytes was established as a proxy for viable spore formation of either type. We also calculated the spore abortion ratio (sign of reduced spores) in several taxa, including the apo-sex hybrid Dryopteris × critica and its 16 apomictically formed offspring.
RESULTS
Four of 15 sampled taxa yielded offspring variable in genome size. Specifically, each variable taxon formed one viable reduced plant among 12-451 sampled gametophytes per taxon. Thus, haploid spore formation in the studied apomicts was very rare but possible. Spore abortion analyses indicated gradually decreasing abortion (haploid spore formation) over time. In Dryopteris × critica, abortion decreased from 93.8% to mean 89.5% in one generation.
CONCLUSIONS
Our results support apomixis as a transitionary phase toward sexuality. Newly formed apomicts hybridize with sexual relatives and continue to form haploid spores early on. Thus, they may get the genomic content necessary for regular meiosis and restore sexuality. If the missing relative goes extinct, the lineage gets locked into apomixis as may be the case with the Dryopteris affinis complex.
Topics: Ferns; Genome Size; Apomixis; Spores; Genome, Plant; Hybridization, Genetic
PubMed: 38762794
DOI: 10.1002/ajb2.16332 -
Reproduction in Domestic Animals =... May 2024Chlorogenic acid (CGA) is an effective phenolic antioxidant that can scavenge hydroxyl radicals and superoxide anions. Herein, the protective effects and mechanisms...
Chlorogenic acid (CGA) is an effective phenolic antioxidant that can scavenge hydroxyl radicals and superoxide anions. Herein, the protective effects and mechanisms leading to CGA-induced porcine parthenogenetic activation (PA) in early-stage embryos were investigated. Our results showed that 50 μM CGA treatment during the in vitro culture (IVC) period significantly increased the cleavage and blastocyst formation rates and improved the blastocyst quality of porcine early-stage embryos derived from PAs. Then, genes related to zygotic genome activation (ZGA) were identified and investigated, revealing that CGA can promote ZGA in porcine PA early-stage embryos. Further analysis revealed that CGA treatment during the IVC period decreased the abundance of reactive oxygen species (ROS), increased the abundance of glutathione and enhanced the activity of catalase and superoxide dismutase in porcine PA early-stage embryos. Mitochondrial function analysis revealed that CGA increased mitochondrial membrane potential and ATP levels and upregulated the mitochondrial homeostasis-related gene NRF-1 in porcine PA early-stage embryos. In summary, our results suggest that CGA treatment during the IVC period helps porcine PA early-stage embryos by regulating oxidative stress and improving mitochondrial function.
Topics: Animals; Oxidative Stress; Parthenogenesis; Mitochondria; Embryo Culture Techniques; Chlorogenic Acid; Embryonic Development; Reactive Oxygen Species; Blastocyst; Swine; Membrane Potential, Mitochondrial; Antioxidants; Female; Glutathione
PubMed: 38757656
DOI: 10.1111/rda.14596