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In May 2023, The Guardian announced that babies had been born through mitochondrial replacement therapy (MRT). MRT and its ethical and legal implications have been discussed in the media for over a decade. These discussions have been examined by social scientists and communication scholars. In this article, we seek to determine whether and, if so, how social representations have changed since this announcement. Using thematic analysis and social representations theory, we studied a corpus of 70 English language newspaper articles. Results show three thematic dichotomies: (1) moderation vs. sensationalism; (2) ontologising vs. de-ontologising MRT; and (3) using metaphors for persuasion vs. explanation. The societal concern representation largely dominated reporting around 2015 and the hope and opportunity representation was prominent in current reporting. We argue that the hope representation may facilitate greater patient and public acceptance of MRT but that it may also limit awareness, understanding and discussion of its possible risks and limitations.

STUDY QUESTION How do oocyte donors and recipients perceive the genetic link related to the transfer of nuclear DNA between donors and offspring? SUMMARY ANSWER Whether they are donors or recipients, individuals attach great importance to the transmission of their genetic heritage, since 94.5% would opt for the pronuclear transfer method to preserve this genetic link in the context of oocyte donation. WHAT IS KNOWN ALREADY Since 1983, the use of oocyte donation has increased worldwide. Performed in France since the late 1980s and initially offered to women with premature ovarian insufficiency, its indications have progressively expanded and now it is proposed in many indications to prevent the transmission of genetically inherited diseases. This has resulted in an increase in the waiting time for access to oocyte donation due to the difficulty in recruiting oocyte donors in French ART centres. Several articles have discussed how to fairly distribute donor oocytes to couples, but few have interviewed women in the general population to record their feelings about oocyte donation, as either the donor or recipient and the importance given to the genetic link between the oocyte donors and the children born. Mitochondrial replacement therapy (MRT) is a technique originally developed for women at risk of transmitting a mitochondrial DNA mutation. Recently, MRT has been considered for embryo arrest and oocyte rejuvenation as it could help females to reproduce with their own genetic material through the transfer of their oocyte nucleus into a healthy donor oocyte cytoplasm. STUDY DESIGN, SIZE, DURATION We conducted an opinion survey from January 2021 to December 2021, during which 1956 women completed the questionnaire. Thirteen participants were excluded from the analysis due to incomplete responses to all the questions. Consequently, 1943 women were included in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS We specifically developed a questionnaire for this study, which was created and distributed using the Drag'n Survey® software. The questionnaire consisted of 21 items presented alongside a video created with whiteboard animation software. The aim was to analyse whether certain factors, such as age, education level, marital status, number of children, use of ART for pregnancy, video viewing, and knowledge about oocyte donation, were associated with feelings towards oocyte donation, by using a univariate conditional logistic regression model. This statistical method was also used to assess whether women would be more inclined to consider oocyte donation with the pronuclear transfer technique rather than the whole oocyte donation. All parameters found to be statistically significant in the univariate analysis were subsequently tested in a multivariate model using logistic regression. MAIN RESULTS AND THE ROLE OF CHANCE Most women were concerned about the biological genetic contribution of the donated oocyte (94.8%). The most common reason for a women's reluctance to donate their oocytes was their unwillingness to pass on their genetic material (33.3%). Nearly 70% of women who were initially hesitant to donate their oocytes indicated that they would reconsider their decision if the oocyte donation was conducted using donated cytoplasm and the pronuclear transfer technique. Concomitantly, >75% of the respondents mentioned that it would be easier to receive a cytoplasm donation. The largest proportion of the population surveyed (94.5%) expressed their support for its legalization. LIMITATIONS, REASONS FOR CAUTION In this study, a substantial portion of the responses came from individuals with medical or paramedical backgrounds, potentially introducing a recruitment bias among potential donors. The rate of missing responses to the question regarding the desire to become an oocyte donor was 13.6%, while the question about becoming an oocyte cytoplasm donor had a missing response rate of 23%. These missing responses may introduce a bias in the interpretation of the data. WIDER IMPLICATIONS OF THE FINDINGS This study was the first to demonstrate that, for the French population studied, the combination of oocyte cytoplasm donation with pronuclear transfer could offer a promising approach to enhance the acceptance of oocyte donation for both the donor and the recipient. STUDY FUNDING/COMPETING INTEREST(S) No external funding was used for this study. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

Until recently, scientific consensus held firm that genetically manipulated embryos created through methods including Mitochondrial Replacement Therapy or human germline genome editing should not be used to initiate a pregnancy. In countries that have relevant laws pertaining to heritable human germline modifications, the vast majority prohibit or restrict this practice. In the last several years, scholars have observed a transformation of scientific and policy restrictions with insistent calls for creating a regulatory pathway. Multiple stakeholders highlight the role of social consensus and public engagement for governance of heritable human germline modifications. However, in the drive to gain public acceptance and lift restrictions, some proponents provide distorted or misleading narratives designed to influence public perception and incrementally shift the consensus. This article describes eight discrete strategies that proponents employ to influence framing, sway public opinion, and revise policymaking of human germline modifications in a manner that undermines honest engagement. [ABSTRACT FROM AUTHOR]

Type 2 diabetes (T2D) presents significant global health and economic challenges, contributing to complications such as stroke, cardiovascular disease, kidney dysfunction, and cancer. The current review explores the crucial role of mitochondria, essential for fuel metabolism, in diabetes-related processes. Mitochondrial deficits impact insulin-resistant skeletal muscles, adipose tissue, liver, and pancreatic β-cells, affecting glucose and lipid balance. Exercise emerges as a key factor in enhancing mitochondrial function, thereby reducing insulin resistance. Additionally, the therapeutic potential of mitochondrial uncoupling, which generates heat instead of ATP, is discussed. We explore the intricate link between mitochondrial function and diabetes, investigating genetic interventions to mitigate diabetes-related complications. We also cover the impact of insulin deficiency on mitochondrial function, the role of exercise in addressing mitochondrial defects in insulin resistance, and the potential of mitochondrial uncoupling. Furthermore, a comprehensive analysis of Mitochondrial Replacement Therapies (MRT) techniques is presented. MRTs hold promise in preventing the transmission of mitochondrial disease. However, addressing ethical, regulatory, and technical considerations is crucial. Integrating mitochondrial-based treatments requires a careful balance between innovation and safety. Ethical dimensions and regulatory aspects of MRT are examined, emphasizing collaborative efforts for the responsible advancement of human health. [ABSTRACT FROM AUTHOR]

Gene editing and mitochondrial replacement therapy (MRT) are biotechnologies used to modify the host nuclear and mitochondrial DNA, respectively. Gene editing is the modification of a region of the host genome using site-specific nucleases, in particular the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system. Heritable and somatic genome editing (HGE and SGE) are used in gene therapy. MRT is a technique used to substitute the defective mitochondria in the recipient embryo with a female donor healthy mitochondrion in order to prevent the inheritance of mothers' defective mitochondria resulting in the change of mitochondria of the entire generation to come. To evaluate the perception of the Nigerian citizens on human genome modification, two survey forms were created and distributed in-person and majorly online. There was a total of 268 responses, 188 from the public and 80 from health workers and bio-scientists. The results showed poor knowledge about gene editing and MRT by the Nigerian public, but its use to prevent and cure inherited diseases was supported. Morality and religion have great influence on the attitude of Nigerians towards genome modification, but the influence of religion and morality is not unequivocal. Multiple regression analysis of Nigerian public responses shows that gender (females), age (19–30 years), monthly income (NGN 0 to 30,000), and level of education (tertiary) are significantly associated with approval of human genome editing, but the survey of health workers and bio-scientists shows no significant association except for females who approve and Muslims who disapprove of human genome editing. [ABSTRACT FROM AUTHOR]

Mitochondrial replacement technology (MRT) aims to reduce the risk of serious disease in children born to women who carry pathogenic mitochondrial DNA (mtDNA) variants. By transplanting nuclear genomes from eggs of an affected woman to enucleated eggs from an unaffected donor, MRT creates new combinations of nuclear and mtDNA. Based on sets of shared sequence variants, mtDNA is classified into ~30 haplogroups. Haplogroup matching between egg donors and women undergoing MRT has been proposed as a means of reducing mtDNA sequence divergence between them. Here we investigate the potential effect of mtDNA haplogroup matching on clinical delivery of MRT and on mtDNA sequence divergence between donor/recipient pairs. Our findings indicate that haplogroup matching would limit the availability of egg donors such that women belonging to rare haplogroups may have to wait > 4 years for treatment. Moreover, we find that intra‐haplogroup sequence variation is frequently within the range observed between randomly matched mtDNA pairs. We conclude that haplogroup matching would restrict the availability of MRT, without necessarily reducing mtDNA sequence divergence between donor/recipient pairs. Synopsis: Haplogroup‐defining mtDNA sequence variants do not preclude within‐haplogroup variation. Comparison of variant counts between haplogroup matched and random mtDNA pairings indicates that matching would not necessarily reduce sequence divergence between egg donors and women undergoing MRT. Women belonging to rare haplogroups may have to wait several years for a suitable haplogroup matched egg donor.High levels of sequence divergence within many rare haplogroups limits the potential of haplogroup matching to reduce sequence divergence between egg donors and women belonging to rare haplogroups. [ABSTRACT FROM AUTHOR]

Mitochondrial replacement technology (MRT) is an emerging and complex bioethical issue. This treatment aims to eliminate maternal inherited mitochondrial DNA (mtDNA) disorders. For Muslims, its introduction affects every aspect of human life, especially the five essential interests of human beings—namely, religion, life, lineage, intellect, and property. Thus, this technology must be assessed using a comprehensive and holistic approach addressing these human essential interests. Consequently, this article analyses and assesses tri-parent baby technology from the perspective of Maqasidic bioethics—that is, Islamic bioethics based on the framework of Maqasid al-Shariah. Using this analysis, this article suggests that tri-parent baby technology should not be permitted for Muslims due to the existence of third-party cell gametes which lead to lineage mixing and due to the uncertain safety of the therapy itself and because the major aim of the technology is to fulfil the affected couples interest to conceive their own genetically healthy child, not to treat and cure mtDNA disorders sufferers. [ABSTRACT FROM AUTHOR]

The second polar body (PB2) transfer in assisted reproductive technology is regarded as the most promising mitochondrial replacement scheme for preventing the mitochondrial disease inheritance owing to its less mitochondrial carryover and stronger operability. However, the mitochondrial carryover was still detectable in the reconstructed oocyte in conventional second polar body transfer scheme. Moreover, the delayed operating time would increase the second polar body DNA damage. In this study, we established a spindleprotrusion- retained second polar body separation technique, which allowed us to perform earlier second polar body transfer to avoid DNA damage accumulation. We could also locate the fusion site after the transfer through the spindle protrusion. Then, we further eliminated the mitochondrial carryover in the reconstructed oocytes through a physically based residue removal method. The results showed that our scheme could produce a nearly normal proportion of normal-karyotype blastocysts with further reduced mitochondrial carryover, both in mice and humans. Additionally, we also obtained mouse embryonic stem cells and healthy live-born mice with almost undetectable mitochondrial carryover. These findings indicate that our improvement in the second polar body transfer is conducive to the development and further mitochondria carryover elimination of reconstructed embryos, which provides a valuable choice for future clinical applications of mitochondrial replacement. [ABSTRACT FROM AUTHOR]

Mitochondrial replacement therapy (MRT) utilises nuclear transfer technology to replace defective mitochondria with healthy ones and thereby minimise the risk of a mitochondrial disease passing from a mother to her child. It promises much but comes with ethical controversy, significant risk of harm and many unknowns. Forming a position on MRT requires accurate information about the current state of knowledge, and an appreciation of the ethical issues at stake. Ethical deliberations will vary depending on the framework used. There are in principle objections to MRT on the grounds of direct harm to human embryos and germline genetic modification. But even without these objections MRT can be weighed in terms of the balance between risks and benefits, alternatives and uncertainties. This paper explores the evidence and lays out the relevant issues to assist such a deliberation. [ABSTRACT FROM AUTHOR]

Mitochondrial replacement therapy (MRT), also called nuclear genome transfer and mitochondrial donation, is a new technique that can be used to prevent the transmission of mitochondrial DNA diseases. Apart from the United Kingdom, the first country to approve MRT in 2015, Australia became the second country with a clear regulatory path for the clinical applications of this technique in 2021. The rapidly evolving clinical landscape of MRT makes the elaboration and evaluation of the responsible use of this technology a pressing matter. As jurisdictions with less strict or non-existent reproductive laws are continuing to use MRT in the clinical context, the need to address the underlying ethical issues surrounding MRT's clinical translation is fundamental. [ABSTRACT FROM AUTHOR]

Enucleated egg donation is increasingly used for mitochondrial replacement therapy and in assisted conception to improve the success rate for women with recurrent IVF failure. With the possibility of a future increase in demand for enucleated egg donation, it is important to understand the attitudes of the general public and egg donors towards it. This Viewpoint elaborates on the general public's and donors' perspectives on important aspects of enucleated egg donation that need to be explored, and points towards the areas that need to be researched in the future., (Crown Copyright © 2024. Published by Elsevier Ltd. All rights reserved.)

Mitochondrial replacement therapy (MRT) in Canada is considered a criminal offense according to article 5(1)(f) of the Assisted Human Reproduction Act (AHRA) (2004). The Act prohibits any practice that modifies the genome of “a human being or in vitro embryo such that the alteration is capable of being transmitted to descendants.” We carried out 32 semi-structured interviews with clinicians, researchers, patient groups, egg donors, and members of the public to explore their attitudes toward the clinical implementation of MRT in Canada. Our interview guide was informed by the socio-ethical, legal, and scientific literature of MRT. We used a thematic analysis to identify and analyze emerging themes and sub-themes. Our findings were divided into five broad themes: (i) an outdated criminal ban, (ii) motives for using MRT, (iii) terminology, (iv) practical and theoretical risks and benefits, and (v) the feasibility of clinical translation in Canada. Although the public and stakeholders’ views on the feasibility of foreseeable translation of MRT in Canadian clinics varied, there was consensus on conducting an overdue review of the current AHRA ban on MRT.

As the vital organelles for cell energy metabolism, mitochondria are essential for oocyte maturation, fertilization, and embryo development. Abnormalities in quantity, quality, and function of mitochondria are closely related to poor fertility and disorders, such as decreased ovarian reserve (DOR), premature ovarian aging (POA), and ovarian aging, as well as maternal mitochondrial genetic disease caused by mitochondrial DNA (mtDNA) mutations or deletions. Mitochondria have begun to become a therapeutic target for infertility caused by factors such as poor oocyte quality, oocyte aging, and maternal mitochondrial genetic diseases. Mitochondrial replacement therapy (MRT) has attempted to use heterologous or autologous mitochondria to rebuild healthy state of oocyte by increasing the amount of mitochondria (e.g., partial ooplasm transfer, autologous mitochondrial transfer), or to stop the transmission of mtDNA diseases by replacing abnormal maternal mitochondria (e.g., pronuclei transfer, spindle transfer, polar body transfer). Among them, autologous mitochondrial transfer is the most promising therapeutic technology as of today which does not involve using a third party, but its clinical efficacy is controversial due to many factors such as the aging phenomenon of germ line cells, the authenticity of the existence of ovarian stem cells (OSC), and secondary damage caused by invasive surgery to patients with poor ovarian function. Therefore, the research of optimal autologous cell type that can be applied in autologous mitochondrial transfer is an area worthy of further exploration. Besides, the quality of germ cells can also be probably improved by the use of compounds that enhance mitochondrial activity (e.g., coenzyme Q10, resveratrol, melatonin), or by innovative gene editing technologies which have shown capability in reducing the risk of mtDNA diseases (e.g., CRISPR/Cas9, TALENTs). Though the current evidences from animal and clinical trials are not sufficient, and some solutions of technical problems are still needed, we believe this review will guide a new direction in the possible clinical applied mitochondrial-related therapeutic strategies in reproductive medicine. [ABSTRACT FROM AUTHOR]

Mitochondrial DNA (mtDNA), as its name implies, is an embodiment of the mitochondrial genetic information that constitutes about 1% of the mammalian genome. It fills a vital niche in tracing matrilineality; the mtDNA is inherited solely from the mother and plays a crucial role in genealogical research. Even a single mutation in the mtDNA can have debilitating and life-altering consequences. Mothers carrying mtDNA mutations will inevitably pass it on to the future generation. Three-parent In vitro fertilization (IVF), a breakthrough technique, shows promising potential to prevent mothers with mtDNA defects from passing it on to their future generation, while also maintaining the genetic link to their posterity. In this review, I delve into the intricacies of this technique, compare and analyze the difference between maternal spindle transfer and pronuclear transfer, discuss the prospective therapeutic effects, and highlight the ethical concerns surrounding this procedure. Considering the various challenges and ethics of this contentious technique, the paper seeks to answer the rousing question – Is three-parent IVF the answer to preventing mitochondrial defects?

Few discussions of the ethics of mitochondrial 'replacement' techniques have drawn significant ethical distinctions between the two approaches now legal in the U.K. However, Anthony Wrigley, Stephen Wilkinson and John Appleby have together argued that under some circumstances pronuclear transfer (PNT) may be in better ethical standing than maternal spindle transfer (MST). They base their conclusion on what they allege to be different implications of the techniques with respect to non‐identity considerations, which they ground on a version of origin essentialism. I raise a series of problems for their argument, which have cautionary implications for invocations of origin essentialism that go beyond specialized debates regarding MST and PNT. I argue that (i) origin essentialism is a fragile foundation for non‐identity considerations; (ii) gametic essentialism, which Wrigley et al. believe licenses their claims, is more questionable than origin essentialism; (iii) gametic essentialism does not straightforwardly justify their conclusion; and (iv) their conclusion in fact relies on an especially dubious position that we can call chromosomal origin essentialism. No good reasons have yet been supplied to distinguish PNT from MST on ethical grounds, and one should be wary of basing claims with practical impact on fragile foundations relating to origin essentialism. [ABSTRACT FROM AUTHOR]

Mitochondrial replacement therapy (MRT), also known as mitochondrial donation (MD), is promoted as an option to prevent transmission of mitochondrial disorders to offspring. Since its first reported use in humans, MRT has raised numerous ethical and medical concerns. This article will explore the technology behind MRT and arguments in favor of and opposing it, concluding that a response through the lens of Scripture promotes flourishing of individuals and families affected by mitochondrial disorders without sacrificing others in the process. [ABSTRACT FROM AUTHOR]

Mitochondrial disorders affect at least 1 in 5,000 individuals worldwide and are often incurable and fatal. Mitochondrial replacement therapy (MRT) is an in vitro fertilization technique used to prevent the transmission of mitochondrial disorders. Currently, MRT is the only approach that provides mothers who carry a pathogenic variant in their mitochondrial DNA (mtDNA), the opportunity to have a biological child without a mitochondrial disease. MRT involves the combination of nuclear DNA from the egg of the carrier mother and the cytoplasm from an oocyte donor, which contains healthy mitochondria. While MRT was approved for use in the UK in 2015, the ban on congressional funding for research on 'heritable genetic modification' has made MRT unavailable within the US borders. This survey‐based study aimed to describe genetic counselors' experience, knowledge, and opinions about MRT. Additionally, we also assessed whether genetic counselors' comfort discussing MRT with patients, and feelings about clinical use of MRT in the United States changed after providing information about MRT compared with baseline. Responses were received from 139 genetic counselors in North America. Findings indicate low awareness and knowledge about MRT among participants. However, more participants expressed comfort with discussing MRT with patients and more participants were able to form opinions about statements about MRT after they were provided with information about MRT. This study is the first to assess genetic counselors' opinions toward MRT and suggests the need for more education about novel technologies such as MRT among genetic counselors. [ABSTRACT FROM AUTHOR]

Mitochondrial DNA (mtDNA), as its name implies, is an embodiment of the mitochondrial genetic information that constitutes about 1% of the mammalian genome. It fills a vital niche in tracing matrilineality; the mtDNA is inherited solely from the mother and plays a crucial role in genealogical research. Even a single mutation in the mtDNA can have debilitating and life-altering consequences. Mothers carrying mtDNA mutations will inevitably pass it on to the future generation. Three-parent In vitro fertilization (IVF), a breakthrough technique, shows promising potential to prevent mothers with mtDNA defects from passing it on to their future generation, while also maintaining the genetic link to their posterity. In this review, I delve into the intricacies of this technique, compare and analyze the difference between maternal spindle transfer and pronuclear transfer, discuss the prospective therapeutic effects, and highlight the ethical concerns surrounding this procedure. Considering the various challenges and ethics of this contentious technique, the paper seeks to answer the rousing question - Is three-parent IVF the answer to preventing mitochondrial defects?. [ABSTRACT FROM AUTHOR]

It has recently been argued that reproductive genetic manipulation technologies like mitochondrial replacement and germline CRISPR modifications cannot be said to save anyone's life because, counterfactually, no one would suffer more or die sooner absent the intervention. The present article argues that, on the contrary, reproductive genetic manipulations may be life-saving (and, from this, have therapeutic value) under an appropriate population health perspective. As such, popular reports of reproductive genetic manipulations potentially saving lives or preventing disease are not necessarily mistaken, though such terminology still requires further empirical validation. [ABSTRACT FROM AUTHOR]

The distinction between germline and somatic gene editing is fundamental to the ethics of human gene editing. Multiple conferences of scientists, ethicists, and policymakers, and multiple professional bodies, have called for moratoria on germline gene editing, and editing of human germline cells is considered to be an ethical "red line" that either never should be crossed, or should only be crossed with great caution and care. However, as research on germline gene editing has progressed, it has become clear that not all germline interventions are alike, and that these differences make a significant moral difference, when it comes to ethical questions about research, regulation, clinical application, and medical justification. In this paper, I argue that, rather than lumping all germline interventions together, we should distinguish between revising, correcting, and transferring genes, and I assess the consequences of this move for the ethics of gene editing. [ABSTRACT FROM AUTHOR]

The field of reproductive medicine has been criticized for introducing ARTs without systematic research on possible safety risks and for failing to meet the standards of evidence-based innovation held elsewhere in medicine. In this paper, firstly, we ask whether 'responsible innovation' has been a concern for the field, and if so, how it has understood the practical implications of this idea for the development and introduction of potentially risky new ARTs. Secondly, we consider whether the field has indeed fallen short of its responsibilities in this respect, and if so, how things can be improved. To answer these questions, we present three case studies involving the introduction of a new reproductive technology: ICSI, preimplantation genetic testing and mitochondrial replacement therapy. As a framework for analyzing these cases, we used Per Sandin's account of the four dimensions of dealing with risks (threat, uncertainty, action, command) that are central to debates about the possible role of the so-called precautionary principle. We conclude that, although offspring safety concerns have been on the agenda of the debate about bringing the relevant technologies to the clinic, systematic safety and effectiveness studies were not always conducted. As professionals in assisted reproduction have a responsibility to take account of the welfare of the children they are creating, we suggest a policy of proceeding with systematic caution. Legal measures may be needed to ensure that professional guidance is followed in practice. Finally, an open question concerns the threshold for acceptable risk in the context of introducing new ARTs. Multiple stakeholders, including professional societies and patient organizations, should have a role in the urgent debate about this. [ABSTRACT FROM AUTHOR]

Mutations in mitochondrial DNA (mtDNA) that occur in oocytes cause the maternal inherited disorders, known as mitochondrial genetic disease. Mitochondrial genetic diseases usually occur in infants, while most of inherited mtDNA -related diseases affect the function of multiple organs and systems. Therefore, mitochondrial genetic diseases are a series of disabling and fatal diseases that could endanger human health seriously, without effective medical treatment. Those female patients with mitochondrial genetic diseases are not recommended to give birth. Genetic characteristics of mtDNA make the prenatal and pre-pregnancy counseling more difficult for many women with pathogenic mtDNA mutations. The modern reproductive genetic interventions could be considered to reduce the risk of inherited mtDNA -related diseases transmitted to offspring. Preimplantation genetic testing (PGT) and prenatal diagnostic techniques may detect the level of mtDNA mutations, and select normal embryos for transplantation or prevent the birth of offspring with the high levels of mutations. However, these techniques may not be appropriate for all patients. The mitochondrial replacement technique has brought new hope for the prevention of serious inherited mtDNA-related diseases, which is expected to minimize the risk of mtDNA-related diseases in their offspring. The long-term safety and effectiveness should be further studied. [ABSTRACT FROM AUTHOR]

Canada's Assisted Human Reproduction Act is long overdue for Parliamentary review. We argue that the current regulation of research using human reproductive materials is not proportionate, not responsive to the uncertain threats posed to human and environmental health and safety, and is not considerate of diverse values in a democratic society. We propose tailored regulatory carve-outs for in vitro research for currently prohibited activities, such as gene editing, and for the exercise of Ministerial Discretion for access by Canadians to experimental in vivo interventions that are currently prohibited, such as mitochondrial replacement therapy. Our recommendations are bounded by constitutional constraints that recognize political and practical challenges in keeping oversight of this research under Federal jurisdiction, whether conducted in academic or private sectors. The proposed nuanced regulatory scheme should be overseen by a new national Agency, modeled on a blend of the Canadian Stem Cell Oversight Committee and Assisted Human Reproduction Canada.

The mitochondrial genome is an evolutionarily persistent and cooperative component of metazoan cells that contributes to energy production and many other cellular processes. Despite sharing the same host as the nuclear genome, the multi-copy mitochondrial DNA (mtDNA) follows very different rules of replication and transmission, which translate into differences in the patterns of selection. On one hand, mtDNA is dependent on the host for its transmission, so selections would favour genomes that boost organismal fitness. On the other hand, genetic heterogeneity within an individual allows different mitochondrial genomes to compete for transmission. This intra-organismal competition could select for the best replicator, which does not necessarily give the fittest organisms, resulting in mito-nuclear conflict. In this review, we discuss the recent advances in our understanding of the mechanisms and opposing forces governing mtDNA transmission and selection in bilaterians, and what the implications of these are for mtDNA evolution and mitochondrial replacement therapy.

In a recent publication Tom Douglas and Katrien Devolder have proposed a new account of genetic parenthood, building on the work of Heidi Mertes. Douglas and Devolder's account aims to solve, among other things, the question of who are the genetic parents of an individual created through somatic cell nuclear transfer (i.e. cloning): (a) the nuclear DNA provider or (b) the progenitors of the nuclear DNA provider. Such a question cannot be answered by simply appealing to the folk account of genetic parenthood, according to which the genetic parents of an individual are those individuals who produced the egg and sperm, respectively, which fused to create the embryo. It cannot be so as in cloning there is no fertilization as such. In this article I critically examine Douglas and Devolder's new account of genetic parenthood and demonstrate that it is vulnerable to counterexamples that exploit the lack of a condition specifying that genetic parents should cause a child's coming into existence. [ABSTRACT FROM AUTHOR]

Concordant with their origin as separate organisms, mitochondria contain their own DNA, called mitochondrial DNA [[11]] (mtDNA). mtDNA retains many features of bacterial DNA, including exquisite susceptibility to damage, rapid mutagenesis, and limited repair capacity. Perhaps some mtDNA mutants gain a replicative advantage vis a vis wild type mtDNA, the natural bottleneck provided by oogenesis fails to exclude all abnormal mtDNA, and/or variation in some nuclear-encoded DNA promotes survival of mutant mtDNA [[16]]. Most genome-wide association studies (GWAS) filter out the high copy number mtDNA, so they do not look for association between mtDNA gene variants and disease. Initially, accumulation of mtDNA mutations in human oocytes provided an attractive hypothesis to pull together the diverse manifestations of oocyte aging [[11]]. [Extracted from the article]

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The purpose of the paper is to explore novel means to overcome the controversial ban in the USA against mitochondrial replacement therapy, a form of IVF, with the added step of replacing a woman's diseased mutated mitochondria with a donor's healthy mitochondria to prevent debilitating and often fatal mitochondrial diseases. Long proven effective in non-human species, MRT recently performed in Mexico resulted in the birth of a healthy baby boy. We explore the ethics of the ban, the concerns over hereditability of mitochondrial disease and its mathematical basis, the overlooked role of Mitochondrial Eve, the financial burden of mitochondrial diseases for taxpayers, and a woman's reproductive rights. We examine applicable court cases, particularly protection of autonomy within the reproductive rights assured by Roe v Wade. We examine the consequences of misinterpreting MRT as genetic engineering in the congressional funding prohibitions causing the MRT ban by the FDA. Allowing MRT to take place in the USA would ensure a high standard of reproductive medicine and safety for afflicted women wishing to have genetically related children, concurrently alleviating the significant financial burden of mitochondrial diseases on its taxpayers. Since MRT does not modify any genome, it falls outside the "heritable genetic modification" terminology of concern to Congress and the FDA. Correcting this terminology, the IOM's conclusion that MRT is ethical, the continuing normalcy of the first MRT recipient, and increasing public awareness of the promising benefits might be all that is required to modify the FDA's position on MRT. [ABSTRACT FROM AUTHOR]

We seek to develop a plausible conception of genetic parenthood, taking a recent discussion by Heidi Mertes as our point of departure. Mertes considers two conceptions of genetic parenthood—one invoking genetic resemblance and the other genetic inheritance—and presents counter‐examples to both conceptions. We revise Mertes' second conception so as to avoid these and related counter‐examples. [ABSTRACT FROM AUTHOR]

Background The first live birth following the use of a new reproductive technique, maternal spindle transfer (MST), which is a mitochondrial replacement technique (MRT), was accomplished by dividing the execution of the MST procedure between two countries, the USA and Mexico. This was done in order to avoid US legal restrictions on this technique. Sources of data Academic articles, news articles, documents obtained through freedom of information requests, laws, regulations and national reports. Areas of agreement MRTs are new reproductive techniques that present novel ethical and legal challenges, since genetic material from three people is employed to create a child. Areas of controversy Could the first MST procedure that culminated in a live birth negatively impact reproductive medicine in Mexico? Growing points The USA and Mexico need specific and clear legislation on MRTs, in order for such techniques not to be governed by prior existing legislation on assisted reproduction that is inadequate for dealing with the new challenges that these techniques present. Areas timely for developing research There is a pressing need for work to be done on the international governance of new reproductive techniques. [ABSTRACT FROM AUTHOR]

Mitochondrial diseases are a group of clinical disorders caused by mutations in the genes encoded by either the nuclear or the mitochondrial genome involved in mitochondrial oxidative phosphorylation. Disorders become evident when mitochondrial dysfunction reaches a cell-specific threshold. Similarly, the severity of disorders is related to the degree of gene mutation. Clinical treatments for mitochondrial diseases mainly rely on symptomatic management. Theoretically, replacing or repairing dysfunctional mitochondria to acquire and preserve normal physiological functions should be effective. Significant advances have been made in gene therapies, including mitochondrial replacement therapy, mitochondrial genome manipulation, nuclease programming, mitochondrial DNA editing, and mitochondrial RNA interference. In this paper, we review the recent progress in these technologies by focusing on advancements that overcome limitations. [Display omitted] • Update of recent advances in mitochondrial genome engineering • Summary of mitochondrial replacement, mtDNA editing and mtRNA interference • Focus on progress in conquering technical bottlenecks [ABSTRACT FROM AUTHOR]

Mitophagy is a process that selectively degrades mitochondria in cells, and it involves a series of signaling events. Our recent paper shows that the ectopic expression of SQSTM1 and its MAP1LC3B-binding domain (Binding) at the mitochondrial outer membrane, can directly cause mitophagy. To distinguish this mitophagy from others, we called it forced mitophagy. Further results show that the forced mitophagy can degrade half of the mitochondria and their DNA in HeLa cells and mouse embryos. Meanwhile, there are no apparent effects on mitochondrial membrane potential (MMP), reactive oxygen species (ROS), mitosis and embryo development. Thus, the forced mitophagy was examined to selectively degrade mitochondrial carryover in the nuclear donor embryos' mitochondria by pre-labeling with Binding before mitochondrial replacement therapy (MRT). The results show that the forced mitophagy can reduce mitochondrial carryover from an average of 4% to 0.09% compared to the controls in mouse embryos and tissues. In addition, the offspring from MRT mice show negligible effects on growth, reproduction, exercise and behavior. Furthermore, results from human tri-pronuclear embryos show that the forced mitophagy results in undetectable mitochondrial carryover in 77% of embryos following MRT. Therefore, forced mitophagy is efficient and safe for degrading mitochondrial carryover in MRT. [ABSTRACT FROM AUTHOR]

Mutant mitochondrial DNA gives rise to a broad range of incurable inborn maladies. Prevention may now be possible by replacing the mutation-carrying mitochondria of zygotes or oocytes at risk with donated unaffected counterparts. However, mitochondrial replacement therapy is being held back by theological, ethical, and safety concerns over the loss of human zygotes and the involvement of a donor. These concerns make it plain that the identification, validation, and regulatory adjudication of novel embryo-sparing donor-independent technologies remains a pressing imperative. This Opinion highlights three emerging embryo-sparing donor-independent options that stand to markedly allay theological, ethical, and safety concerns raised by mitochondrial replacement therapy. [ABSTRACT FROM AUTHOR]

With the recent report of a live birth after use of mitochondrial replacement therapy, sometimes called 'three-parent IVF', the clinical application of the technique is fast becoming a reality. While the United Kingdom allows the procedure under regulatory scrutiny, it remains effectively outlawed in many other countries. We argue that such prohibitions may violate individuals' procreative rights, grounded in individuals' interest in genetic affinity. The interest in genetic affinity was recently endorsed by Singapore's highest court, reflecting an emphasis on the importance of biological ties found across the globe. We apply that reasoning to make the case for a right to 'three-parent IVF'. [ABSTRACT FROM AUTHOR]

This paper examines whether there are moral differences between the mitochondrial replacement techniques that have been recently developed in order to help women afflicted by mitochondrial DNA diseases to have genetically related children absent such conditions: maternal spindle transfer (MST) and pronuclear transfer (PNT). Firstly, it examines whether there is a moral difference between MST and PNT in terms of the divide between somatic interventions and germline interventions. Secondly, it considers whether PNT and MST are morally distinct under a therapy/creation optic. Finally, it investigates whether there is a moral difference between MST and PNT from a human embryo destruction point of view. I conclude, contra recent arguments, that regarding the first two points there is no moral differences between PNT and MST; and that regarding the third one MST is morally preferable to PNT, but only if we hold a gradualist account of the moral value of human embryos where zygotes have slight moral value. [ABSTRACT FROM AUTHOR]

It has been suggested that deleterious interactions between the mitochondrial and nuclear genomes could pose a problem for mitochondrial replacement therapy (MRT). This is because the mitochondrial genome is placed in a novel nuclear environment using this technique. In contrast, it is inherited with half the mother's genome during normal reproduction, a genome that it is relatively compatible with, since the mother is alive. Here, I review the evidence of whether mito-nuclear interactions are likely to pose a problem for MRT. The majority of the available experimental evidence, both in humans and other species, suggests that MRT is not harmful. These results are consistent with population genetic theory, which predicts that deleterious mito-nuclear interactions are unlikely to be much more prevalent in individuals born to MRT than normal reproduction, particularly in a species such as humans with low population differentiation. This is because selection is unlikely to be strong enough to establish significant linkage disequilibrium between the mitochondrial and nuclear genomes. These results are supported by a meta-analysis of 231 cases, from a variety of animals, in which the mitochondrial DNA (mtDNA) from one strain has been introgressed into the nuclear background of another strain of the same species. Overall, there is little tendency for introgression of mtDNA to be harmful. [ABSTRACT FROM AUTHOR]