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Applied & Translational Genomics Dec 2016The use of mitochondrial transfer as a clinic procedure is drawing closer to reality. Here we provide a detailed overview of mitochondrial transfer techniques - both... (Review)
Review
The use of mitochondrial transfer as a clinic procedure is drawing closer to reality. Here we provide a detailed overview of mitochondrial transfer techniques - both established and recent - including pronuclear, spindle, ooplasmic and blastomere transfer. Reasons as to why some techniques are more suitable for the prevention of mitochondrial DNA disease than others, as well as the advantages and disadvantages of each methodology, are discussed. The possible clinical introduction of these techniques has raised concerns about the adverse effects they may have on resultant embryos and offspring. Success rates of each technique, embryo viability and developmental consequences post mitochondrial transfer are addressed through analysis of evidence obtained from both animal and human studies. Counterarguments against potential mitochondrial-nuclear genome incompatibility are also provided. Additional clinical applications of mitochondrial transfer techniques are discussed. These include the rescue or enhancement of fertility in women of advanced maternal age or those suffering from diabetes. An alternative to using mitochondrial DNA transfer for germ line therapies is the therapeutic use of somatic cell nuclear transfer for the generation of personalised stem cells. Although ethically challenging, this method could offer patients already suffering from mitochondrial DNA diseases a novel treatment option.
PubMed: 28018848
DOI: 10.1016/j.atg.2016.10.001 -
The Journal of Cell Biology Jul 2023Regulated recruitment and activity of motor proteins is essential for intracellular transport of cargoes, including messenger ribonucleoprotein complexes (RNPs). Here,...
Regulated recruitment and activity of motor proteins is essential for intracellular transport of cargoes, including messenger ribonucleoprotein complexes (RNPs). Here, we show that orchestration of oskar RNP transport in the Drosophila germline relies on interplay between two double-stranded RNA-binding proteins, Staufen and the dynein adaptor Egalitarian (Egl). We find that Staufen antagonizes Egl-mediated transport of oskar mRNA by dynein both in vitro and in vivo. Following delivery of nurse cell-synthesized oskar mRNA into the oocyte by dynein, recruitment of Staufen to the RNPs results in dissociation of Egl and a switch to kinesin-1-mediated translocation of the mRNA to its final destination at the posterior pole of the oocyte. We additionally show that Egl associates with staufen (stau) mRNA in the nurse cells, mediating its enrichment and translation in the ooplasm. Our observations identify a novel feed-forward mechanism, whereby dynein-dependent accumulation of stau mRNA, and thus protein, in the oocyte enables motor switching on oskar RNPs by downregulating dynein activity.
Topics: Animals; Drosophila melanogaster; Drosophila Proteins; Dyneins; Kinesins; Oocytes; Ribonucleoproteins; RNA, Messenger; RNA-Binding Proteins; RNA Transport
PubMed: 37213090
DOI: 10.1083/jcb.202301113 -
Biology of Reproduction Mar 2009New techniques to boost male and female fertility are being pioneered at a rapid pace in fertility clinics to increase the efficiency of assisted reproduction methods in...
New techniques to boost male and female fertility are being pioneered at a rapid pace in fertility clinics to increase the efficiency of assisted reproduction methods in couples in which natural conception has not been achieved. This study investigates the possible epigenetic effects of ooplasm manipulation methods on postnatal growth and development using a mouse genetic model, with particular emphasis on the possible effects of intergenotype manipulations. We performed interstrain and control intrastrain maternal pronuclear transfers, metaphase-II spindle transfers, and ooplasm transfer between C57BL/6 and DBA/2 mice, and found no major, long-term growth defects or epigenetic abnormalities, in either males or females, associated with intergenotype transfers. Ooplasm transfer itself was associated with reduced viability, and additional subtle effects of ooplasm strain of origin were observed. Both inter- and intrastrain ooplasm transfer were associated with subtle, transient effects on growth early in life. We also performed inter- and intrastrain germinal vesicle transfers (GVTs). Interstrain GVT females, but not males, had significantly lower body weights at birth and thereafter compared with the intrastrain GVT and non-GVT controls. No GVT-associated changes were observed in DNA methylation of the Mup1, Rasgrf1, H19, Snrpn, or Peg3 genes, nor any difference in expression of the imprinted Rasgrf1, Igf2r, or Mest genes. These results indicate that some ooplasm manipulation procedures may exert subtle effects on growth early in life, while intergenotype GVT can result in significant growth deficiencies after birth.
Topics: Animals; Animals, Newborn; Cytoplasm; DNA Methylation; Embryo Culture Techniques; Epigenesis, Genetic; Female; Kruppel-Like Transcription Factors; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Models, Animal; Oocytes; Proteins; Spindle Apparatus; Zygote Intrafallopian Transfer; ras-GRF1
PubMed: 19073997
DOI: 10.1095/biolreprod.108.073593 -
Animals : An Open Access Journal From... Oct 2022In teleost, as in other vertebrates, stress affects reproduction. A key component of the stress response is the pituitary secretion of the adrenocorticotropic hormone...
In teleost, as in other vertebrates, stress affects reproduction. A key component of the stress response is the pituitary secretion of the adrenocorticotropic hormone (ACTH), which binds to the melanocortin 2 receptor (MC2R) in the adrenal glands and activates cortisol biosynthesis. In zebrafish, Mc2r was identified in male and female gonads, while ACTH has been shown to have a physiological role in modulating reproductive activity. In this study, the hypothesis that other melanocortins may also affect how the zebrafish gonadal function is explored, specifically steroid biosynthesis, given the presence of members of the melanocortin signaling system in zebrafish gonads. Using cell culture, expression analysis, and cellular localization of gene expression, our new observations demonstrated that melanocortin receptors, accessory proteins, antagonists, and agonists are expressed in both the ovary and testis of zebrafish ( = 4 each sex). Moreover, melanocortin peptides modulate both basal and gonadotropin-stimulated steroid release from zebrafish gonads ( = 15 for males and = 50 for females). In situ hybridization in ovaries ( = 3) of zebrafish showed and in follicular cells and adjacent to cortical alveoli in the ooplasm of previtellogenic and vitellogenic oocytes. In zebrafish testes ( = 3), and were detected exclusively in germ cells, specifically in spermatogonia and spermatocytes. Our results suggest that melanocortins are, directly or indirectly, involved in the endocrine control of vitellogenesis in females, through modulation of estradiol synthesis via autocrine or paracrine actions in zebrafish ovaries. Adult zebrafish testes were sensitive to low doses of ACTH, eliciting testosterone production, which indicates a potential role of this peptide as a paracrine regulator of testicular function.
PubMed: 36290123
DOI: 10.3390/ani12202737 -
PloS One 2020Several equids have gone extinct and many extant equids are currently considered vulnerable to critically endangered. This work aimed to evaluate whether domestic horse...
Several equids have gone extinct and many extant equids are currently considered vulnerable to critically endangered. This work aimed to evaluate whether domestic horse oocytes support preimplantation development of zebra embryos obtained by intracytoplasmic sperm injection (ICSI, zebroid) and cloning, and to study the Hippo signaling pathway during the lineage specification of trophectoderm cells and inner cell mass cells. We first showed that zebra and horse sperm cells induce porcine oocyte activation and recruit maternal SMARCA4 during pronuclear formation. SMARCA4 recruitment showed to be independent of the genetic background of the injected sperm. No differences were found in blastocyst rate of ICSI hybrid (zebra spermatozoon into horse egg) embryos relative to the homospecific horse control group. Interestingly, zebra cloned blastocyst rate was significantly higher at day 8. Moreover, most ICSI and cloned horse and zebra blastocysts showed a similar expression pattern of SOX2 and nuclear YAP1 with the majority of the nuclei positive for YAP1, and most SOX2+ nuclei negative for YAP1. Here we demonstrated that horse oocytes support zebra preimplantation development of both, ICSI and cloned embryos, without compromising development to blastocyst, blastocyst cell number neither the expression of SOX2 and YAP1. Our results support the use of domestic horse oocytes as a model to study in vitro zebra embryos on behalf of preservation of valuable genetic.
Topics: Adaptor Proteins, Signal Transducing; Animals; Cell Nucleus; Cloning, Organism; Cytoplasm; Embryo Culture Techniques; Embryonic Development; Endangered Species; Equidae; Female; Gene Expression Profiling; Horses; In Vitro Techniques; Male; Nuclear Transfer Techniques; Oocytes; SOXB1 Transcription Factors; Sperm Injections, Intracytoplasmic; Sus scrofa
PubMed: 32915925
DOI: 10.1371/journal.pone.0238948 -
Reproductive Biology and Endocrinology... Oct 2017Ooplasmic transfer (OT) technique or cytoplasmic transfer is an emerging technique with relative success, having a significant status in assisted reproduction. This... (Review)
Review
BACKGROUND
Ooplasmic transfer (OT) technique or cytoplasmic transfer is an emerging technique with relative success, having a significant status in assisted reproduction. This technique had effectively paved the way to about 30 healthy births worldwide. Though OT has long been invented, proper evaluation of the efficacy and risks associated with this critical technique has not been explored properly until today. This review thereby put emphasis upon the applications, efficacy and adverse effects of OT techniques in human.
MAIN BODY
Available reports published between January 1982 and August 2017 has been reviewed and the impact of OT on assisted reproduction was evaluated. The results consisted of an update on the efficacy and concerns of OT, the debate on mitochondrial heteroplasmy, apoptosis, and risk of genetic and epigenetic alteration.
SHORT CONCLUSION
The application of OT technique in humans demands more clarity and further development of this technique may successfully prove its utility as an effective treatment for oocyte incompetence.
Topics: Cytoplasm; Embryo, Mammalian; Female; Genes, Mitochondrial; Humans; Mitochondria; Oocyte Donation; Oocytes; Reproductive Techniques, Assisted; Treatment Outcome
PubMed: 28969648
DOI: 10.1186/s12958-017-0292-z -
Nature Communications Jun 2022A decrease in oocyte developmental potential is a major obstacle for successful pregnancy in women of advanced age. However, the age-related epigenetic modifications...
A decrease in oocyte developmental potential is a major obstacle for successful pregnancy in women of advanced age. However, the age-related epigenetic modifications associated with dynamic transcriptome changes, particularly meiotic maturation-coupled mRNA clearance, have not been adequately characterized in human oocytes. This study demonstrates a decreased storage of transcripts encoding key factors regulating the maternal mRNA degradome in fully grown oocytes of women of advanced age. A similar defect in meiotic maturation-triggered mRNA clearance is also detected in aged mouse oocytes. Mechanistically, the epigenetic and cytoplasmic aspects of oocyte maturation are synchronized in both the normal development and aging processes. The level of histone H3K4 trimethylation (H3K4me3) is high in fully grown mouse and human oocytes derived from young females but decreased during aging due to the decreased expression of epigenetic factors responsible for H3K4me3 accumulation. Oocyte-specific knockout of the gene encoding CxxC-finger protein 1 (CXXC1), a DNA-binding subunit of SETD1 methyltransferase, causes ooplasm changes associated with accelerated aging and impaired maternal mRNA translation and degradation. These results suggest that a network of CXXC1-maintained H3K4me3, in association with mRNA decay competence, sets a timer for oocyte deterioration and plays a role in oocyte aging in both mouse and human oocytes.
Topics: Animals; Female; Histones; Humans; Meiosis; Mice; Oocytes; Pregnancy; RNA Stability; RNA, Messenger; RNA, Messenger, Stored; Trans-Activators
PubMed: 35680896
DOI: 10.1038/s41467-022-30928-x -
Animal Science Journal = Nihon Chikusan... Sep 2016Centrosome integrity and microtubule network are crucial to the events around fertilization, including pronuclear development, migration and fusion, and the first... (Review)
Review
Centrosome integrity and microtubule network are crucial to the events around fertilization, including pronuclear development, migration and fusion, and the first mitotic division. The present review highlights the importance of bull spermatozoal centrosomes to function as a microtubule-organizing center for successful fertilization and the subsequent embryonic development. Spermatozoal centrosomes need to be blended with ooplasmic pericentriolar materials accurately to nucleate and organize the sperm aster. Dysfunction of the spermatozoal centrosomes is associated with fertilization failure, which has been overcome with supplemental stimuli for oocyte activation following intracytoplasmic sperm injection in humans. Even though the spermatozoal centrosomes are functionally intact, abnormal sperm aster formation was frequently observed in vitrified-warmed bovine oocytes, with delayed pronuclear development and migration. Treatment of the post-warm oocytes with Rho-associated coiled-coil kinase inhibitor or α-tocopherol inhibited the incidence of the abnormal aster formation, resulting in higher blastocyst yields following in vitro fertilization and culture. Thus, understanding of centrosomal function made it possible to improve the performance of advanced reproductive technologies.
Topics: Animals; Cattle; Centrosome; Embryonic Development; Enzyme Inhibitors; Female; Fertilization; Fertilization in Vitro; Humans; Male; Microtubule-Organizing Center; Oocytes; Reproductive Techniques, Assisted; Sperm Injections, Intracytoplasmic; Spermatozoa; alpha-Tocopherol; rho-Associated Kinases
PubMed: 27169525
DOI: 10.1111/asj.12621 -
Science Advances Oct 2023In worms, epigenetic information transmits transgenerationally. Still, it is unknown whether the effects transfer to the next generation inside or outside of the...
In worms, epigenetic information transmits transgenerationally. Still, it is unknown whether the effects transfer to the next generation inside or outside of the nucleus. Here, we use the tractability of gene-specific double-stranded RNA-induced silencing to demonstrate that RNA interference can be inherited independently of any nuclear factors via mothers that are genetically engineered to transmit only their ooplasm but not the oocytes' nuclei to the next generation. We characterize the mechanisms and, using RNA sequencing, chimeric worms, and sequence polymorphism between different isolates, identify endogenous small RNAs which, similarly to exogenous siRNAs, are inherited in a nucleus-independent manner. From a historical perspective, these results might be regarded as partial vindication of discredited cytoplasmic inheritance theories from the 19th century, such as Darwin's "pangenesis" theory.
Topics: Animals; Caenorhabditis elegans; RNA, Small Interfering; RNA Interference; Caenorhabditis elegans Proteins; Gene Silencing; RNA, Double-Stranded
PubMed: 37878696
DOI: 10.1126/sciadv.adj8618 -
BMC Developmental Biology Jul 2009Interspecies somatic cell nuclear transfer (iSCNT) has been proposed as a tool to address basic developmental questions and to improve the feasibility of cell therapy....
BACKGROUND
Interspecies somatic cell nuclear transfer (iSCNT) has been proposed as a tool to address basic developmental questions and to improve the feasibility of cell therapy. However, the low efficiency of iSCNT embryonic development is a crucial problem when compared to in vitro fertilization (IVF) and intraspecies SCNT. Thus, we examined the effect of donor cell species on the early development of SCNT embryos after reconstruction with bovine ooplasm.
RESULTS
No apparent difference in cleavage rate was found among IVF, monkey-bovine (MB)-iSCNT, and bovine-bovine (BB)-SCNT embryos. However, MB-iSCNT embryos failed to develop beyond the 8- or 16-cell stages and lacked expression of the genes involved in embryonic genome activation (EGA) at the 8-cell stage. From ultrastructural observations made during the peri-EGA period using transmission electron microscopy (TEM), we found that the nucleoli of MB-iSCNT embryos were morphologically abnormal or arrested at the primary stage of nucleologenesis. Consistent with the TEM analysis, nucleolar component proteins, such as upstream binding transcription factor, fibrillarin, nucleolin, and nucleophosmin, showed decreased expression and were structurally disorganized in MB-iSCNT embryos compared to IVF and BB-SCNT embryos, as revealed by real-time PCR and immunofluorescence confocal laser scanning microscopy, respectively.
CONCLUSION
The down-regulation of housekeeping and imprinting genes, abnormal nucleolar morphology, and aberrant patterns of nucleolar proteins during EGA resulted in developmental failure in MB-iSCNT embryos. These results provide insight into the unresolved problems of early embryonic development in iSCNT embryos.
Topics: Animals; Cattle; Cell Nucleolus; Cell Nucleus; Cytoplasm; Embryo, Mammalian; Embryonic Development; Genome; Macaca mulatta; Nuclear Transfer Techniques; Oocytes
PubMed: 19635167
DOI: 10.1186/1471-213X-9-44