The epigenetic contribution to phenotype is now well established. Studies over the past decade have shown that proteins that are able to establish and propagate epigenetic modifications are essential for mammalian development. Some of the genes involved in these processes have been identified, but the roles of many remain unknown. The mutagenesis screens for modifiers of position effect variegation in Drosophila suggest that there are over 200 genes that are able to modify epigenetic variegation. We emulated this screen in the mouse to identify mammalian modifiers of a variegating transgene. The screen aimed to identify novel genes involved in epigenetic reprogramming, and to generate mouse models to study the impact of disruption to the epigenome. Inbred male mice carrying a variegating GFP transgene expressed in erythrocytes were mutagenised with ENU. Offspring were screened by flow cytometry and in the initial rounds of mutagenesis, 11 dominant mutant lines were identified. These lines were called MommeDs (Modifiers of murine metastable epialleles, dominant). This thesis describes the mapping and phenotypic characterisation of three Momme lines: MommeD7, MommeD8 and MommeD9. The MommeD9 mutation enhances variegation and was mapped to a 3.4 Mb interval on Chromosome 7. A mutation in a 5? splice site was found in the Trim28 gene. Analysis of Trim28 mRNA and protein in heterozygotes showed that the mutant allele was null. Homozygotes die before mid-gestation. Heterozygotes are viable but display variable and complex phenotypes, including infertility, obesity, behavioural abnormalities and premature death. Obese MommeD9 mice have liver steatosis, impaired glucose tolerance and other indicators of metabolic syndrome. This phenotype has not previously been reported for mice haploinsufficient for Trim28. There is considerable variability of phenotypes among inbred MommeD9 heterozygotes, which suggests a role for epigenetics in phenotypic noise or “intangible variation”. MommeD8 is a semi-dominant enhancer of variegation. Some homozygotes are viable but some die around birth. Viable homozygotes weigh less than wildtype littermates and have increased CpG methylation at the GFP transgene enhancer element. The mutation was mapped to a 4 Mb interval on chromosome 4. Extensive candidate gene sequencing failed to find a mutation and so DNA from mutant and wildtype individuals were sequenced across the entire linked interval by 454 Sequencing technology. MommeD8 individuals carry two point mutations, one is intergenic and the other lies in an intron of the Ppie gene. Analysis of Ppie mRNA in heterozygotes and homozygotes shows that mutants have reduced transcript levels, suggesting that a deficiency in Ppie causes the increased silencing of GFP. The Ppie gene has not been reported to be involved in epigenetic reprogramming and little is known about its function. Mice heterozygous for MommeD7 have a marked increase in expression of GFP. Heterozygotes have a range of hematopoietic abnormalities including splenomegaly, anaemia and reticulocytosis. Homozygotes die at birth and appear pale. The increased GFP in the peripheral blood appears to be the consequence of an increase in reticulocytes. The mutation is linked to a 1.5 Mb interval on Chromosome 7. MommeD7 mice appear to have hematopoietic abnormalities that affect the expression of the erythroid-specific GFP reporter transgene. MommeD7 mice serve as a reminder that, as well as discovering bona fide modifiers of epigenetic reprogramming, the ENU screen can also identify hematopoietic mutants.

Yes / Rapid qualitative studies conducted with patient and public involvement can help promote policy-relevant and efficient research. There is a need to understand the experiences of researchers, patients, and members of the public to guide the development of good practice and to determine the extent to which rapid qualitative research can be implemented in PPIE projects. We conducted a qualitative study to explore the experiences of research teams that carried out studies using rapid techniques with patient and public involvement. We carried out 26 interviews with researchers, coordinators, patients, carers, service users and members of the public. This study identified needs which related to practical and time constraints. Rapid qualitative research tends to be limited to certain PPIE groups, and particular phases of the research process. Study findings are rarely discussed with PPIE members. The educational needs of rapid qualitative research were also identified. Researchers and PPIE members considered three main issues: a lack of training on patient involvement for researchers, rapid qualitative research training for PPIE members, and the diversity of PPIE members. We found that rapid researchers were able to involve patients and members of the public in research despite time pressures. The challenges identified in this study can be used to plan future training programmes for researchers and PPIE panel members and develop strategies to recruit PPIE panel members from a wide range of backgrounds. The research aim was to explore the experiences of those carrying out rapid qualitative studies with PPIE. As such, the participants of this study included patients, carers, service users and members of the public, who were interviewed individually. A lived experienced researcher and PPIE member for a hospital conducted the design, data collection and analysis of the study. The study brief was to interview researchers only. The lived-experience researcher initiated the inclusion of PPIE members as participants, therefore strengthening the study design. We shared the draft report with the PPIE participants for participant validation and to maintain a continuous feedback relationship. This led to addressing key issues in designing and involving PPIE members in more meaningful and equal ways. Whilst there is agreement on activities which centre on PPIE, there is no consensus on how to achieve these in high quality rapid qualitative studies.