Master of Science in Medicine (by research) / Assisted reproductive technologies (ARTs) are very efficient in producing embryos, however many of these embryos have poor viability. No more than 50% of IVF embryos complete preimplantation development (Hardy et al. 2001). The poor viability is manifested as a reduced rate of cell proliferation and increased rates of apoptosis in the early embryo, resulting in high rates of embryo mortality (Hardy et al. 2001). The reduced viability occurs as a response to a range of cellular stressors that are a consequence of embryo culture (Hardy et al. 2001). The stress of culture disrupts some survival signalling pathways, metabolism of substrates and induces redox stress (Hardy et al. 2001). The cellular stress sensor p53 is expressed in the early embryo but is normally kept at very low levels (Li et al. 2005). This latency may be breached in IVF embryos following culture of zygotes in vitro for 96 hours, resulting in the up-regulation and nuclear accumulation of p53 (Li et al. 2005). Activation of the p53 stress-sensing pathway in the early mouse embryo by culture in vitro causes a marked loss of their developmental competence (Li et al. 2005). This study aimed to establish whether benefits could be obtained by culturing mice IVF embryos in the presence of p53 protein inhibitors. IVF zygotes were cultured individually in 10µl drops of 1.25, 2.5, 5 or 10µM Pifithrin-a (PFTa) in 0.05% DMSO for 96 hours. On day 5 the development stage was assessed. Embryos reaching the blastocyst stage were fixed and stained with Hoechst 33342 for total cell count and the proportion of nuclei with normal and abnormal morphology. There was an increase in the blastocyst rate, total cell count and the proportion of nuclei in a blastocyst with normal nuclei in 10µM-treated embryos. This study also aimed to determine whether benefits could be obtained by incubating mouse IVF sperm with p53 protein inhibitors during IVF. IVF sperm was treated with 1.25, 2.5, 5 or 10µM of PFTa in 0.05% DMSO during incubation with oocytes for 6 hours. Resulting zygotes were cultured for 96 hours individually in 10µl drops of MODHTFM. On day 5 the development stage was assessed. Embryos reaching the blastocyst stage were fixed and stained with Hoechst 33342 for total cell count and the proportion of nuclei with normal and abnormal morphology. There was a reduction in the proportion of fragmented nuclei in blastocysts derived from 1.25 and 10µM-treated sperm. 10µM treated sperm increased the total cell count, the proportion of normal nuclei in a blastocyst and the blastocyst development rate. IVF sperm incubated with 1.25µM PFTa during insemination of oocytes increased the fertilisation rate. Another aim of this study was to establish whether p53 siRNA could inhibit p53 mRNA in mice IVF embryos and if so, whether this would improve embryo viability in culture. IVF zygotes were transfected with 15nM p53 small inhibiting RNA (siRNA) and 0.8% Oligofectamine Reagent immediately, 24 h, 48 h and 72 h after IVF then cultured individually in 10µl drops of MOD-HTFM for a total of 96 hours. On day 5 the blastocyst rate was assessed and immunofluorescence performed probing for p53. There was no significant reduction in p53 expression and no improvement in blastocyst rate at any of the transfection times. However, there was a decrease in the proportion of nuclei which expressed p53 when p53 siRNA was transfected 72 hours after IVF. Also, it was determined that siRNA was efficiently being delivered into the preimplantation embryo with Oligofectamine Reagent. Lastly, this study aimed to determine whether mice sperm with p53 gene deletions have a selective advantage in fertilising the oocyte compared to their wild-type counterparts. p53+/- males were mated with p53+/+ females and the resulting zygotes genotyped after 24 hours of culture. More than 50% of offspring had a p53+/+ genotype. There was no selective advantage for p53 null sperm to fertilise the oocyte, there was actually a disadvantage. The selective disadvantage for p53 null sperm to fertilise the F1 hybrid oocyte in IVF compared to its wild-type counterparts may imply that p53 null sperm are not as viable and may have a survival disadvantage. The reduction in fertility of p53 null sperm in vitro infers that p53 function may be important for the fertility of the mouse sperm in vitro. The results of this thesis could establish means of improving human embryo viability in ART, some examples being P53 protein inhibition in preimplantation embryos during culture prior to transfer to the uterus, or P53 protein inhibition in IVF sperm. The use of the new technology, p53 siRNA was not effective in inhibiting p53 expression, although the build-up experiments determined that siRNA is efficiently delivered into the preimplantation embryo with Oligofectamine Reagent. The demonstration that p53 null sperm has a selective disadvantage in fertilising the oocyte compared to their wild-type counterparts does not indicate a positive selection pressure for naturally occurring mutations to this gene. And so, there is no concern regarding the genetic and epigenetic risks to progeny arising from assisted reproductive technologies with respect to sperm.

Preimplantation genetic diagnosis is a technique used in the field of assisted reproduction. The technique is applied to embryos that have been created in vitro, in order to facilitate the selection of embryos according to particular genetic parameters. The use of preimplantation genetic diagnosis by prospective parents at high risk for having a child affected by a genetic disorder has facilitated the birth of unaffected children. Preimplantation genetic diagnosis has already been used for other purposes, such as screening for gender, and could in principle be used to screen for a wide range of genetic traits. The aim of this thesis is to provide good answers to the ethical questions provoked by the advent and continuing development of preimplantation genetic diagnosis. The thesis is divided into four parts. Part One provides a brief overview of the science of genetic selection. Part Two is centred on a discussion of two ethical principles. The principle of procreative liberty is based upon the idea that acts of interference in the reproductive lives of others should be avoided unless there is good justification for such acts. The principle of procreative beneficence is based upon the idea that prospective parents should select the child, of the possible children they could have, who is expected to have the best life. I will argue that the principle of procreative liberty should be applied to acts of interference in individuals� freedom to use preimplantation genetic diagnosis, while the principle of procreative beneficence should be applied to acts of selecting children. In Part Three, I will endorse a position that accords embryos a relatively low moral status, reject the arguments of the disability rights critique, argue that the eugenic aspects of preimplantation genetic diagnosis do not warrant much concern, and develop a framework for critically evaluating slippery slope arguments. Finally, in Part Four, specific applications of preimplantation genetic diagnosis will be examined in detail. Although each application raises unique ethical questions, this thesis aims to demonstrate that the consistent application of the principles and preliminary conclusions developed in Parts Two and Three provides the best means for determining how PGD should be used and which uses should be restricted.

<p>The more geneticists discover about which genes cause what traits, the more medical practitioners as well as ethicists will have to deal with questions such as which of the myriad of identifiable conditions could or should be allowed for preimplantation genetic diagnosis (PGD) and subsequent implantation via in vitro fertilization. Not a lot of controversy seems to be raised when it comes to performing PGD for serious genetic conditions such as Tay-Sachs disease or Lesch-Nyhan syndrome, but what about other characteristics, for example, those which we normally would call disabilities? This thesis tackles this question, and in partifular the possibility of implanting embryos with that screen positive for deafness, as deaf parents, especially those coming from the Deaf community who see their condition as a positive part of their identity and cultural belongingness, have expressed interest in ensuring the birth of a deaf child. This thesis thus raises the questions: is deafness a disease, or just an unfortunate condition? Are the deaf justified in purposefully implanting a baby diagnosed to be deaf? The thesis tries to grapple with why deaf parents may want deaf children, and show how these wishes may be justified. Concluding that neither the medical model of disease nor the principle-based approach—which weighs beneficence, nonmaleficence, autonomy and justice—are sufficient in opposing the implantation of deaf babies, it is proposed that a different theory, model or philosophy of health should be espoused if we are still to find the implantation of deaf babies problematic. That is, while the mainstream may ask: “Why ensure the birth of a deaf child?”, we ask, “Why not?” Policymakers and ethicists must be able to tackle this question sufficiently if they would allow to screen for deafness, but only to ensure the birth of hearing children.</p>

The more geneticists discover about which genes cause what traits, the more medical practitioners as well as ethicists will have to deal with questions such as which of the myriad of identifiable conditions could or should be allowed for preimplantation genetic diagnosis (PGD) and subsequent implantation via in vitro fertilization. Not a lot of controversy seems to be raised when it comes to performing PGD for serious genetic conditions such as Tay-Sachs disease or Lesch-Nyhan syndrome, but what about other characteristics, for example, those which we normally would call disabilities? This thesis tackles this question, and in partifular the possibility of implanting embryos with that screen positive for deafness, as deaf parents, especially those coming from the Deaf community who see their condition as a positive part of their identity and cultural belongingness, have expressed interest in ensuring the birth of a deaf child. This thesis thus raises the questions: is deafness a disease, or just an unfortunate condition? Are the deaf justified in purposefully implanting a baby diagnosed to be deaf? The thesis tries to grapple with why deaf parents may want deaf children, and show how these wishes may be justified. Concluding that neither the medical model of disease nor the principle-based approach—which weighs beneficence, nonmaleficence, autonomy and justice—are sufficient in opposing the implantation of deaf babies, it is proposed that a different theory, model or philosophy of health should be espoused if we are still to find the implantation of deaf babies problematic. That is, while the mainstream may ask: “Why ensure the birth of a deaf child?”, we ask, “Why not?” Policymakers and ethicists must be able to tackle this question sufficiently if they would allow to screen for deafness, but only to ensure the birth of hearing children.

Šiame magistro baigiamajame darbe lyginamuoju metodu yra analizuojamas preimplantacinės diagnostikos reguliavimas įvairiose pasaulio valstybėse, tuo pačiu atskleidžiant pagrindines iš to kylančias problemas. Tyrimas atliktas siekiant palyginti skirtingų valstybių teisės aktus ir patirtį šioje biomedicinos srityje. Atlikta analizė rodo, kad preimplantacinė diagnostika vis dar yra pakankamai nauja ir atsargiai vertinama procedūra, sukelianti daug etinių ir teisinių diskusijų, o teisinis reguliavimas priklauso nuo valstybės teisinių, religinių, kultūrinių, socialinių tradicijų. / These master theses analyze the regulation of preimplantation genetic diagnosis in comparative aspect in different countries, simultaneously revealing main problems arising. The aim of this research is to compare legal acts and experience of different countries in this biomedical field. The analysis shows, that preimplantation genetic diagnosis is still innovative and well considered procedure, which give a rise to a lot of ethical and legal discussions, and legal regulation of this procedure depends on legal, religious, cultural and social traditions of the country.

The aim of the present study was to investigate the experiences and attitudes concerningpreimplantation genetic diagnosis (PGD) among the couples that have undergone PGD in Sweden.PGD is an alternative to conventional prenatal diagnosis for couples with a high risk of having a childwith genetic disease. Couples opting for PGD have to perform in vitro fertilisation, generatedembryos are subjected to biopsy and diagnosis, and healthy embryos can be transferred to the femaleuterus. Hopefully a pregnancy will be established. However, PGD is a strategy that implies bothphysical and psychological stress, and it is not obvious that this is an easier alternative than prenataldiagnosis. A questionnaire was sent to 116 couples that had carried out at least one PGD treatmentcycle. The response rate was 89%, thus almost all couples treated in Sweden since the start in 1995was represented. Results: The stress, both psychologically and physically, caused by the PGD treatment was evaluatedsomewhere between “As expected” and “More stressful than expected”. The stress experienced duringthe PGD treatments was not associated with the couples’ previous reproductive experiences. The mostphysical stressful event was the oocyte retrieval and the most psychologically stressful period was“waiting for a possibly/ hopefully embryo transfer”.The majority of couples that had performed prenatal diagnosis on a spontaneous pregnancy andexperienced a PGD treatment reported that PGD was more physically stressful (54%), but that prenataldiagnosis was more psychologically stressful (51%). The couples reported the reproductivealternatives chosen after PGD closure, and couples performing PGD at the present rated futurereproductive alternatives. Results indicated that ocyte- and sperm donations were a less attractivealternative than for example adoption. Participants in the study also had the opportunity to state forwhom /which indications PGD should be an option. Conclusion: The stress associated with performing PGD or prenatal diagnosis is extensive and noneof the alternatives is an obvious choice. PGD was reported as more physical stressful, but prenataldiagnosis was more psychologically stressful. The reproductive pathways chosen after PGD closurewas reported, and surprisingly sperm and oocyte donations were not attractive alternatives. The choiceof reproductive alternatives might be influenced by the information and support provided by thehealthcare personal. Knowledge about the experience of PGD treatments is of great importance forthose that meet these couples for genetic and reproductive counselling, in order to give them propercare and to better meet their demand of information and support.

The purpose of this thesis is to query the legitimacy of offering preimplantation genetic diagnostic (PGD) testing against Down's syndrome on the basis of United Kingdom (UK) law and policies. I will argue that extending PGD testing for Down’s syndrome as a permissible use of this technology does not (straightforwardly) adhere with the Human Fertilisation and Embryology Authority (HFEA) Code of Practice's stated factors which are to be considered when assessing the appropriateness of PGD applications. Indeed, due consideration of the evidence given in the relevant literature about the capacities and quality of life possible for persons living with Down's syndrome would seriously call into question the validity of a positive judgment recommending PGD as a treatment service for Down's syndrome according to the current UK regulatory instruments. I end the thesis by considering why the HFEA's relatively recent decision to limit client access according to an exclusive list of "serious" and therefore "in principle" test-worthy genetic conditions—understood as legitimate applications for PGD—stands to entrench prejudice, stigma, social bias, and unfair discrimination against the disadvantaged social group of persons living with Down's syndrome.

Preimplantation genetic diagnosis is a technique used in the field of assisted reproduction. The technique is applied to embryos that have been created in vitro, in order to facilitate the selection of embryos according to particular genetic parameters. The use of preimplantation genetic diagnosis by prospective parents at high risk for having a child affected by a genetic disorder has facilitated the birth of unaffected children. Preimplantation genetic diagnosis has already been used for other purposes, such as screening for gender, and could in principle be used to screen for a wide range of genetic traits. The aim of this thesis is to provide good answers to the ethical questions provoked by the advent and continuing development of preimplantation genetic diagnosis. The thesis is divided into four parts. Part One provides a brief overview of the science of genetic selection. Part Two is centred on a discussion of two ethical principles. The principle of procreative liberty is based upon the idea that acts of interference in the reproductive lives of others should be avoided unless there is good justification for such acts. The principle of procreative beneficence is based upon the idea that prospective parents should select the child, of the possible children they could have, who is expected to have the best life. I will argue that the principle of procreative liberty should be applied to acts of interference in individuals� freedom to use preimplantation genetic diagnosis, while the principle of procreative beneficence should be applied to acts of selecting children. In Part Three, I will endorse a position that accords embryos a relatively low moral status, reject the arguments of the disability rights critique, argue that the eugenic aspects of preimplantation genetic diagnosis do not warrant much concern, and develop a framework for critically evaluating slippery slope arguments. Finally, in Part Four, specific applications of preimplantation genetic diagnosis will be examined in detail. Although each application raises unique ethical questions, this thesis aims to demonstrate that the consistent application of the principles and preliminary conclusions developed in Parts Two and Three provides the best means for determining how PGD should be used and which uses should be restricted.

ABSTRACT The purpose of this project was to investigate monocarboxylate (i.e. pyruvate and lactate) transport in the preimplantation stage of embryo development. Much progress has been made over the last 15 years towards understanding preimplantation and peri-implantation embryo physiology, including metabolic preferences during this period. It is known that as the cells (blastomeres) of an embryo compact via tight junctions and the embryo differentiates into a blastocyst, a metabolic “switch” occurs to allow the blastocyst to take up glucose at a rapid rate, obtaining energy derived from glycolysis. Glucose transporter molecules have been identified and characterized during this period of development and a paradigm for glucose transport has been described. However, during the early cleavage stages (days 1-3 post-fertilization), the embryo preferentially derives its metabolic energy from the monocarboxylate pyruvate. Evidence for the expression of pyruvate transporter molecules (a family of proton-coupled monocarboxylate co-transporters, MCT) has only been indicated via some kinetic studies on pH homeostasis and PCR analysis for MCT expression, and results have been conflicting (Gibb et al., 1997, Harding et al., 1999, Herubel et al., 2002). This project aimed to clarify discrepancies in reports for mRNA expression of MCT and to enhance the understanding of monocarboxylate transport processes during preimplantation development by pioneering investigations into protein expression for various MCT isoforms. Transport kinetics for monocarboxylate, DL-lactate, were examined by measuring the uptake of radioactive [3H]-DL-lactate from the medium by two-cell embryos and blastocysts. It was discovered that blastocysts demonstrate significantly higher affinity for DL-lactate compared to zygotes (Km 20 + 10 v 87 + 35 mM lactate; p=0.03), which suggested that alterations in the expression of various MCT isoforms might be expected as the embryo developed to a blastocyst. The rate of transport showed a trend towards a decrease from the zygote to blastocyst stages, although this could not be confirmed as significant within the limitations of this experiment. Mouse embryos, both in vivo and in vitro-derived, were collected and pooled at the zygote, two-cell, morula and blastocyst stages of development. RNA purification, reverse-transcription and PCR were used to analyze the expression of the four best-characterized MCT isoforms. MCT1, MCT2 and MCT4 were all found to be expressed in oocytes and mouse embryos from the zygote through to the preimplantation blastocyst. MCT3, an isoform uniquely expressed in the retina, was not detected at any stage in embryos. Since glucose has been implicated in regulatory processes involving glucose transporter expression in mouse embryos (Pantaleon et al., 2005, Pantaleon et al., 2001), mRNA expression was examined in the presence or absence of glucose in the culture media to determine whether the same phenomena applied to MCT. It was discovered that MCT1 and MCT4 isoforms were responsive to glucose-deprivation as evidenced by a reduction in mRNA expression in compacted morula cultured from the zygote stage without glucose. When glucose-deprived embryos were exposed to a brief high concentration of glucose during the 4-cell stage of development and continued in culture without glucose, the expression of mRNA for MCT1 and MCT4 persisted post-compaction, demonstrating that glucose exposure is necessary for the continued expression of these two isoforms in the mouse blastocyst. MCT2 mRNA did not respond to the absence of glucose in this way, and mRNA expression persisted in either the presence or absence of glucose. To follow these analyses of MCT gene transcription during early embryo development, confocal laser scanning immunofluorescence and western blotting were used to identify the expression of MCT proteins at various stages of development. Culture in the presence or absence of glucose was again employed to determine whether the changes seen in mRNA expression were conveyed at the protein level. All three proteins were identified throughout preimplantation development, though their locations were uniquely different. MCT1 was notably absent from plasma membranes at all stages, and was detected diffusely within the cytoplasm. In expanding blastocysts MCT1 tended to concentrate in the cortical cytoplasm of blastomeres and staining was more intense in the polar trophectoderm. In this cytoplasmic location its function is unclear. MCT1 does not appear to be a key transporter of monocarboxylates into and out of the embryo, but it may have a role in shuttling pyruvate and lactate within the cytoplasm to maintain metabolic and redox homeostasis. In embryos cultured without glucose, the immunostaining intensity for MCT1 gradually decreased as morulae degenerated and died. Protein loss occurred from the morula stage onwards, whilst mRNA was already undetectable at this stage. This would indicate that glucose signals which maintain mRNA expression most likely operate at the level of gene activation/transcription with latent effects on protein expression. MCT4 appeared to be located on the plasma membranes of oocytes and 2-cell embryos and nuclear staining was evident throughout preimplantation development, however plasma membrane expression was not apparent in morulae and blastocysts. This is consistent with earlier kinetic evidence of a low affinity lactate transporter (Km 87 + 35 mM lactate) operating at the early preimplantation stages. MCT4 has the lowest affinity for lactate of all the characterized MCT to date. Kinetic data also suggests that a change might occur in MCT protein expression as the embryo progresses to a blastocyst with a higher affinity lactate transporter taking precedence, and the loss of MCT4 from the plasma membrane at these later stages supports this view. Similarly to MCT1, MCT4 mRNA expression was also found to be dependent on glucose exposure during the early preimplantation period, and embryos cultured entirely without glucose demonstrated a loss of MCT4 mRNA expression at the morula stage. MCT4 typically exists as a lactate exporter in glycolytic tissues and it most likely exports lactate from the embryo for pH and redox homeostasis during this period of development. Protein localization studies found MCT2 to be located on the plasma membranes of oocytes, zygotes, 2-cell embryos, and polarized to the surface of the outer blastomeres of morulae and blastocyst trophectodermal cells. Throughout preimplantation development, MCT2 protein co-localized with peroxisomal catalase in peroxisome-sized granules throughout the cells. Known to be a high affinity pyruvate transporter, given its location in embryos it was proposed here that MCT2 most likely imports pyruvate to fuel early embryos, and later works as a bifunctional pyruvate/lactate importer/exporter on the transporting epithelium (trophectoderm) of blastocysts to maintain the pH, redox and metabolic status of the embryo. MCT2 was an enigma to the other MCT. Its expression in the absence of glucose behaved in an opposite way to that of MCT1 and MCT4, with mRNA expression persisting in the absence of glucose. In fact, MCT2 and catalase proteins demonstrated a quantitative increase in embryos lacking glucose, and the increase in staining was noticed as an increase in the density of peroxisome-like structures (or peroxisome proliferation) within the embryo. As such, it was decided to investigate the possibility that peroxisome proliferators (Peroxisome Proliferator Activated Receptors, PPARs) were involved in the control of MCT expression in the same way that they are known to control the expression of catalase and other peroxisomal proteins. At this stage, no MCT isoforms had been identified as being under the control of PPARs, although it was known that their expression was most likely controlled at the level of transcription, with no translational or post-translational controlling elements. PPARα, one of three isoforms (α, γ and β/δ) was selected as a likely candidate given that it controls peroxisomal proliferation and fatty acid β-oxidation processes at the level of transcription in other tissues, and it was known to be upregulated in conditions of starvation and oxidative stress. PPARα mRNA was shown to be expressed in early cleavage preimplantation mouse embryos, but its expression was reduced in morulae and blastocysts. Further, lack of glucose led to persistence of PPARα mRNA expression at the morula stage. PPARα protein was also demonstrated to stain more brightly in early preimplantation embryos compared to later stages. Further experimentation demonstrated that the phenomenon of increased catalase and MCT2 expression in embryos cultured without glucose could be mimicked in the presence of glucose by treating these embryos with the PPARα-selective agonist, WY14,643. The timing and quantitative nature of this upregulation were very similar, suggesting that PPARα was in some way involved in the glucose-deprived upregulation pathway for catalase and MCT2. To further investigate this pathway, oxidative stress was investigated in embryos cultured in the presence and absence of glucose to test whether the generation of reactive oxygen species contributed to the PPARα/MCT2 phenomenon. It was demonstrated that within 2 h of culture in the absence of glucose, hydrogen peroxide levels were significantly elevated in zygotes. Amelioration of increased peroxide generation in glucose-deprived embryos using a non-selective flavoenzyme inhibitor diphenyleneiodonium (DPI) eliminated any increases in PPARα and MCT2 protein expression that were earlier noted in the absence of glucose. To summarize, MCT1, MCT2 and MCT4 mRNA and protein expression were successfully demonstrated in mouse preimplantation embryos and all were confirmed to be in some way regulated by glucose in the culture medium. In the absence of glucose, mRNA expression for MCT1 and MCT4 were reduced to undetectable levels in morulae indicating that their expression was glucose-dependent. Paradoxically, glucose deprivation caused an increase in PPARα, catalase and MCT2 protein expression. PPARα-selective agonism in the presence of glucose induced similar timing and effects on catalase and MCT2 upregulation, implicating PPARα in this pathway. Hydrogen peroxide levels were significantly elevated within 2 h of culture in the absence of glucose. This peroxide elevation could be quenched to control levels by treating these embryos with DPI, and reducing hydrogen peroxide to control levels also eliminated the upregulation of PPARα and MCT2, implicating oxidative stress as an important component in the glucose-deprivation induced upregulation of MCT2. The experimental data presented in this thesis demonstrate that from its very conception, the embryo interacts with, adapts to, and is indeed affected by the external environment in which it develops. Even components like glucose, once considered simply as metabolic substrates, have profound effects on gene transcription and protein expression within the embryo which may impact on later its developmental competence, a reality we need to consider more deeply in light of the implementation of artificial reproductive technologies widely used today in zoology, agriculture and clinically, in humans.

Bibliography: leaves 126-147 / xiv, 147 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Summary: Aims to develop reliable procedures for determining the genetic status of embryos derived by IVF procedures prior to implantation. Prenatal diagnosis allows pregnancy to be established using only acceptable embryos / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1994