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Title: Confronting two-tiered community recreation and poor women's exclusion: Promoting inclusion, health and social justice
Author(s): Colleen Reid (author), Wendy Frisby (author), Pamela Ponic (author)
Date: 2002
Abstract: The social, psychological, and physical health benefits of participation in physical activity and other forms of recreation are well documented (Frankish, Milligan and Reid; Sallis and Owen; Reid and Dyck), and evidence suggests that low-income women view access to community recreation as an important dimension of their health and their communities (Weber; Frisby and Hoeber). Although many community recreation departments in Canada have a social mandate of providing services to all citizens to promote health and well being, consistent barriers to regular involvement persist for those who live on the margins and are unable to conform to dominant expectations inherent in modern forms of public recreation (Frisby, Crawford and Dorer; Lyons and Langille;Harvey). With its individualist ideology, classist notions of self-responsibility, and fees for service, we argue that community recreation has become a two-tiered system where only those with sufficient social, cultural, and financial resources can participate (Kidd). Consequently, insufficient subsidies, policies requiring "proof of poverty," and discrimina- tory practices exclude poor women from being actively involved in health-promoting forms of community recreation. The purposes of this paper are: i) to examine how low-income women see involvement in community recreation contributing to their health, and ii) to examine low-income women's experiences with exclusionary community recreation policies and practices. Hearing the voices of those who are marginalized from the knowledge production and policy development process is important when considering how public sector programs, policies, and practices can become more inclusive (Lord and Hutchison; Frisby and Hoeber). Through fostering inclusion rather than classist forms of service delivery, the community development and social justice mandates of many community recreation departments is advanced thus providing health-promoting resources for those living on the margins.
Department: Therapeutic Recreation

Title: Does this feel empowering? Using métissage to explore the effects of critical pedagogy
Author(s): Rebecca D. Cox (author), Meaghan Dougherty (author), Sue L. Hampton (author), Christina Neigel (author), Kim Nickel (author)
Date: 2017
Abstract: The extent to which critical pedagogy disrupts the relations of dominance inside postsecondary classrooms, or empowers students to take socially just action beyond the classroom has been debated and challenged for decades. Through the use of métissage, an interpretive inquiry method that affords collaborative interrogation of individual autoethnographic writings, we five participants in the same critical pedagogy course conducted a post-course inquiry project in order to explore what we had learned through the course. Through this inquiry project, we have come to a deeper understanding of critical pedagogy praxis. Ultimately, what we learned through the use of this inquiry method maintains important implications for postsecondary educators.
Subject(s): Critical pedagogy, Transformative learning, Postsecondary education
Department: Child and Youth Care, Child, Family and Community Studies

Title: Challenges of using progress monitoring measures: insights from practicing clinicians
Author(s): Gabriela Ionita (author), Marilyn Fitzpatrick (author), Jann Tomaro (author), Vivian V. Chen (author), Louise Overington (author)
Date: 2016
Abstract: Although integrating progress monitoring (PM) measures into psychotherapy practice can provide numerous benefits, including improved client outcomes, relatively few clinicians use these measures (e.g., Ionita & Fitzpatrick, 2014). To better understand the reasons for clinicians’ reluctance, consensual qualitative research methodology was used to examine the challenges faced by clinicians currently using PM measures. Open-ended, semistructured interviews, with 25 clinicians who chose to use PM measures, revealed that clinicians tended to face challenges involving technical concerns, negative responses from others, and personal barriers such as anxiety. The majority of participants discussed ways to overcome the challenges they experienced, including ensuring the fit of the PM measure, explaining measures to others to help engender a positive response, adapting their own perspective, and increasing their own and others’ knowledge of the measures. Implications for practicing psychologists and for knowledge translation efforts are discussed.
Subject(s): Evidence-based psychotherapy, Psychotherapy--Outcome assessment, Psychotherapy--Evaluation, Psychotherapy patients--Rehabilitation--Evaluation, Qualitative research
Department: Psychology, Humanities and Social Sciences

Title: Synaptic plasticity is impaired in rats with a low glutathione content
Author(s): W. Almaguer-Melian (author), Reyniel Cruz-Aguado (author), J.A. Bergado (author)
Date: 2000
Abstract: Long-term potentiation (LTP) is a sustained increase in the efficacy of synaptic transmission, based on functional changes involving pre- and postsynaptic mechanisms, and has been considered a cellular model for learning and memory. The sulphurated tripeptide glutathione acts as a powerful antioxidant agent within the nervous system. Recent in vitro studies suggest that the cellular redox status might influence the mechanisms involved in synaptic plasticity. It is not known, however, how glutathione depletion might affect LTP. In the present study, we evaluated the input-output relationships, LTP, and paired-pulse interactions in rats with low glutathione levels induced by systemic injection of diethylmaleate. Our results in anesthetized rats show that the basic synaptic transmission between the perforant pathway and the dentate gyrus granule cells was not affected by glutathione depletion. However, in the same synapses it was not possible to induce prolonged changes in synaptic efficacy (LTP). Paired-pulse facilitation was also absent in the treated animals, suggesting an impairment of short-term synaptic interactions. These findings indicate that low content of glutathione can impair short-term and long-term mechanisms of synaptic plasticity and stress the importance of the redox balance in the normal function of brain circuitry.
Department: Biology

Title: Partial loss of Ascl2 function affects all three layers of the mature placenta and causes intrauterine growth restriction
Author(s): Rosemary Oh-McGinnis (author), Aaron B.Bogutz (author), Louis Lefebvre (author)
Date: 2011
Abstract: Several imprinted genes have been implicated in the regulation of placental function and embryonic growth. On distal mouse chromosome 7, two clusters of imprinted genes, each regulated by its own imprinting center (IC), are separated by a poorly characterized region of 280 kb (the IC1–IC2 interval). We previously generated a mouse line in which this IC1–IC2 interval has been deleted (Del7AI allele) and found that maternal inheritance of this allele results in low birth weights in newborns. Here we report that Del7AI causes a partial loss of Ascl2, a maternally expressed gene in the IC2 cluster, which when knocked out leads to embryonic lethality at midgestation due to a lack of spongiotrophoblast formation. The hypomorphic Ascl2 allele causes embryonic growth restriction and an associated placental phenotype characterized by a reduction in placental weight, reduced spongiotrophoblast population, absence of glycogen cells, and an expanded trophoblast giant cell layer. We also uncovered severe defects in the labyrinth layer of maternal mutants including increased production of the trilaminar labyrinth trophoblast cell types and a disorganized labyrinthine vasculature. Our results have important implications for our understanding of the role played by the spongiotrophoblast layer during placentation and show that regulation of the dosage of the imprinted gene Ascl2 can affect all three layers of the chorio-allantoic placenta.
Department: Biology

Title: Marbled murrelets select distinctive nest trees within old-growth forest patches
Author(s): Michael P. Silvergieter (author), David B. Lank (author)
Date: 2011
Abstract: The coastal old-growth forests of North America’s Pacific Coast are renowned both for their commercial and ecological value. This study adds to growing evidence that selective harvesting of the largest trees may have a disproportionate ecological impact. Marbled Murrelets (Brachyramphus marmoratus), a threatened species, nest almost exclusively in these old-growth forests. Detailed knowledge of nesting habitat selection provides guidance for habitat management and conservation. Habitat selection for this species has been studied at a variety of scales using ground and remote methods. However, because Marbled Murrelet nesting activity is limited to a single mossy platform on a single tree, we investigated nest tree selection within old-growth forest patches, using a set of 59 forest patches containing active nests. Nest trees were usually distinctive compared with neighboring trees in the surrounding 25 m radius patch. They averaged 15 to 20% taller than neighboring trees depending on region, had significantly larger stem diameters, more potential nesting platforms, and more moss. They had the most extreme values of height and width about three times as often as expected by chance. An analysis of moss platform use as a function of number of platforms per platform tree suggests that murrelets select individual platforms, rather than platform trees per se. Nonetheless, highly selective logging practices that remove high-value trees from stands may also remove trees most likely to be selected by nesting murrelets.
Department: Biology

Title: An application of fuzzy BWM for risk assessment in offshore oil projects
Author(s): Reza Ketabchi (author), Mohammad R. Ghaeli (author)
Date: 2019
Abstract: The purpose of this paper is to examine the existing risks for the offshore project and risk weighting using the fuzzy best worst method (FBWM). In offshore oil projects, we face six major risks. Each of these risks is divided into smaller risks leaving us to have a total of 34 risks. Some of these risks are internal and some are external risks. In this method, first, the experts of this field determined the best and the worst type of risk. Then, using the experts’ opinions, the study compared the remaining risks with the two selected risks and the other weights are determined. In our survey, “Technical Risk and Project Execution” is the most important risk factor followed by “Political Risk and Sanctions”, “Market risk”, “Management risk”, “Financial risk and currency fluctuations” and “Environmental risk”.
Subject(s): Offshore oil industry--Risk assessment, Offshore oil industry--Risk management, Offshore oil well drilling--Risk assessment, Project management, Risk assessment, Risk management
Department: Commerce and Business Administration, Computing Studies and Information Systems

Title: Advancing women's social justice agendas: a feminist action research framework
Author(s): Colleen Reid (author)
Date: 2004
Abstract: Feminist action research is a promising, though under-developed, research approach for advancing women's health and social justice agendas. In this article the foundations, principles, dimensions, promises, and challenges of engaging in feminist action research are explored.
Subject(s): Women--Health and hygiene--Research, Women--Health and hygiene--Sociological aspects, Action research, Feminist theory, Feminism
Department: Therapeutic Recreation

Title: The physiology of rock climbing
Author(s): Luisa V. Giles (author), Edward C. Rhodes (author), Jack E. Taunton (author)
Date: 2012
Abstract: In general, elite climbers have been characterised as small in stature, with low percentage body fat and body mass. Currently, there are mixed conclusions surrounding body mass and composition, potentially because of variable subject ability, method of assessment and calculation. Muscular strength and endurance in rock climbers have been primarily measured on the forearm, hand and fingers via dynamometry. When absolute hand strength was assessed, there was little difference between climbers and the general population. When expressed in relation to body mass, elite-level climbers scored significantly higher, highlighting the potential importance of low body mass. Rock climbing is characterised by repeated bouts of isometric contractions. Hand grip endurance has been measured by both repeated isometric contractions and sustained contractions, at a percentage of maximum voluntary contraction. Exercise times to fatigue during repeated isometric contractions have been found to be significantly better in climbers when compared with sedentary individuals. However, during sustained contractions until exhaustion, climbers did not differ from the normal population, emphasising the importance of the ability to perform repeated isometric forearm contractions without fatigue becoming detrimental to performance. A decrease in handgrip strength and endurance has been related to an increase in blood lactate, with lactate levels increasing with the angle of climbing. Active recovery has been shown to provide a better rate of recovery and allows the body to return to its pre-exercised state quicker. It could be suggested that an increased ability to tolerate and remove lactic acid during climbing may be beneficial. Because of increased demand placed upon the upper body during climbing of increased difficulty, possessing greater strength and endurance in the arms and shoulders could be advantageous. Flexibility has not been identified as a necessary determinant of climbing success, although climbing-specific flexibility could be valuable to climbing performance. As the difficulty of climbing increases, so does oxygen uptake (V̇O2), energy expenditure and heart rate per metre of climb, with a disproportionate rise in heart rate compared with V̇O2. It was suggested that these may be due to a metaboreflex causing a sympathetically mediated pressor response. In addition, climbers had an attenuated blood pressure response to isometric handgrip exercises when compared with non-climbers, potentially because of reduced metabolite build-up causing less stimulation of the muscle metaboreflex. Training has been emphasised as an important component in climbing success, although there is little literature reviewing the influence of specific training components upon climbing performance. In summary, it appears that success in climbing is not related to individual physiological variables but is the result of a complex interaction of physiological and psychological factors.
Department: Sport Science

Title: The influence of oviposition experience on response to host pheromone in Trichogramma sibericum (Hymenoptera: Trichogrammatidae)
Author(s): Robert McGregor (author), Deborah Henderson (author)
Date: 1998
Abstract: Searching times and residence times of Trichogramma sibericum Sorokina were measured in the laboratory on individual cranberry leaves that had been treated with the sex pheromone of blackheaded fireworm [Rhopobota naevana (Hübner)] and on leaves that were left untreated. Mean searching time was higher on leaves treated by passive diffusion with either 50 or 100 μg of the main component of fireworm pheromone, (Z)-11-tetradecen-1-ol acetate (Z11-14: Ac), than on control leaves. Mean residence times were also higher on leaves treated by passive diffusion with 50 μg of Z11-14: Ac than on leaves untreated with pheromone. Pretrial oviposition experience in either the presence or the absence of host pheromone did not influence variation in searching time or residence time. This indicates that neither associative learning of the odor of host pheromone nor a more generalized increase in response to chemical stimuli after oviposition (priming) affects retention responses of T. sibericum to pheromone. Results are discussed in the context of current theories on the evolution of learning in insect parasitoids and as they relate to the concurrent use of pheromone-based mating disruption and releases of T. sibericum for pest management of the blackheaded fireworm.
Department: Biology

Title: Trees and the laws of supply and demand : illegal import bans and ecotourism protect tropical forests
Author(s): Roberta Staley (author)
Date: 2019
Subject(s): Forest products industry--Corrupt practices--Tropics, Forest products industry--Environmental aspects--Tropics, Forest products industry--Law and legislation--Tropics, Deforestation--Economic aspects--Tropics, Deforestation--Control--Tropics, Forest conservation--Law and legislation--Tropics, Forest conservation--Economic aspects--Tropics, Offenses against the environment--Law and legislation--Tropics, Ecotourism--Economic aspects--Tropics, Tropics--Environmental conditions
Department: Communications, Language, Literature and Performing Arts

Title: The time lag between a carbon dioxide emission and maximum warming increases with the size of the emission
Author(s): Kirsten Zickfeld (author), Tyler Herrington (author)
Date: 2015
Abstract: In a recent letter, Ricke and Caldeira (2014 Environ. Res. Lett. 9 124002) estimated that the timing between an emission and the maximum temperature response is a decade on average. In their analysis, they took into account uncertainties about the carbon cycle, the rate of ocean heat uptake and the climate sensitivity but did not consider one important uncertainty: the size of the emission. Using simulations with an Earth System Model we show that the time lag between a carbon dioxide (CO2) emission pulse and the maximum warming increases for larger pulses. Our results suggest that as CO2 accumulates in the atmosphere, the full warming effect of an emission may not be felt for several decades, if not centuries. Most of the warming, however, will emerge relatively quickly, implying that CO2 emission cuts will not only benefit subsequent generations but also the generation implementing those cuts. [Publisher Abstract]
Subject(s): Carbon dioxide emissions, Warming commitment, Ocean Thermal Inertia, Earth System Modelling
Department: Geography and the Environment, Humanities and Social Sciences

Title: Ethical challenges in contemporary FASD research and practice: a global health perspective
Author(s): Nina Di Pietro (author), Jantina De Vries (author), Angelina Paolozza (author), Dorothy Reid (author), James N. Reynolds (author), Amy Salmon (author), Marsha Wilson (author), Dan J. Stein (author), Judy Illes (author)
Date: 2016
Abstract: Fetal alcohol spectrum disorder (FASD) is increasingly recognized as a growing public health issue worldwide. Although more research is needed on both the diagnosis and treatment of FASD, and a broader and more culturally diverse range of services are needed to support those who suffer from FASD and their families, both research and practice for FASD raise significant ethical issues. In response, from the point of view of both research and clinical neuroethics, we provide a framework that emphasizes the need to maximize benefits and minimize harm, promote justice, and foster respect for persons within a global context.
Subject(s): Fetal alcohol spectrum disorders, Children of prenatal alcohol abuse--Services for, Neurosciences, Medical ethics, World health, Public health
Department: Psychology, Humanities and Social Sciences

Title: Maintenance of EMG activity and loss of force output with instability
Author(s): Kenneth G. Anderson (author), David G. Behm (author)
Date: 2004
Abstract: Swiss Balls used as a platform for training provide an unstable environment for force production. The objective of this study was to measure differences in force output and electromyographic (EMG) activity of the pectoralis major, anterior deltoid, triceps, latissimus dorsi, and rectus abdominus for isometric and dynamic contractions under stable and unstable conditions. Ten healthy male subjects performed a chest press while supported on a bench or a ball. Unstable isometric maximum force output was 59.6% less than under stable conditions. However, there were no significant differences in overall EMG activity between the stable and unstable protocols. Greater EMG activity was detected with concentric vs. eccentric or isometric contractions. The decreased balance associated with resistance training on an unstable surface may force limb musculature to play a greater role in joint stability. The diminished force output suggests that the overload stresses required for strength training necessitate the inclusion of resistance training on stable surfaces. ABSTRACT FROM AUTHOR
Department: Sport Science

Title: Flora de la región ultramáfica (serpentinícola) de Guamuhaya
Author(s): Alenna V. Glaría (author), Luis R. González-Torres (author), Rosalina B. Iturralde (author), Eldis B. Granados (author)
Date: 2006
Abstract: The ultramafic (serpentine) outcrops of Cuba represent the 7% of Cuban surface and are the largest one of the Caribbean region. Ultramafic soils usually have low levels of nutrients, and toxic levels of Mg and heavy metals. In this paper, we characterize the flora of the Guamuhaya ultramafic region and analyze its possible origin and phytogeographical relationships. This region contains 233 species, 55 of them are Cuban endemism and one (Rondeletia bicolor) is restricted to this region. This flora is mostly composed by Antillean, Neotropical and Central-west Cuban species.
Department: Biology

Title: The effects of social story interventions on preschool age children with and without disabilities
Author(s): Cori M. Moore (author), Nancy M. Sileo (author), Kyle Higgins (author), Richard D. Tandy (author), Michelle Tannock (author)
Date: 2013
Abstract: This study compared the effects of a social story-only intervention with the effects of a social story-plus practices session intervention as implemented with preschool age children with disabilities (n = 16) and without disabilities (n = 16) in an inclusive preschool setting. The social story interventions were implemented with groups of four children in order to examine the impact of the intervention on the children's prosocial and antisocial skills. The findings of the study differ from previous research in that the social story interventions were not found to be an effective intervention. The significance of these findings, limitations of the study, and future research suggestions are discussed.
Subject(s): Social skills in children--Study and teaching (Early childhood), Storytelling--Study and teaching (Early childhood), Storytelling ability in children, Early childhood special education, Inclusive education, Children with disabilities--Education (Early childhood), Early childhood education
Department: Early Childhood Education, Child, Family and Community Studies

Title: ‘The old days of amateurism are over’: the Samaranch revolution and the return of Olympic tennis
Author(s): Matthew P. Llewellyn (author), Robert J. Lake (author)
Date: 2017
Abstract: Tennis featured in every Olympics from 1896 to 1924, after which disagreements between the International Olympic Committee (IOC) and the International Lawn Tennis Federation (ILTF) on matters pertaining to organisational control and the amateur eligibility of players led to tennis being removed from the Olympic Games as a full-medal event until the 1988 Seoul Olympics. This paper traces the steps of the sport’s reinstatement, from when efforts commenced in the 1950s, setting this development in the contexts of: broader political movements, shifting IOC leadership, burgeoning commercialisation of Olympic sport, the concomitant push for professionalisation and the declining influence of amateur ideals within both the Olympic movement and international tennis. Under the leadership of the amateur stalwart Avery Brundage, the IOC stymied attempts to facilitate tennis’s re-entry, challenging both the ILTF on failing to deal with widespread ‘sham-amateur’ practices and the avaricious promoters luring amateur players toward the professional ranks. Brundage and the IOC also strongly condemned the move to ‘open’ tennis and an acceptance of full-blown professionalism. Only a change in leadership, firstly with Lord Killanin and then the progressive reformer Juan Antonio Samaranch, did the IOC recognise the value of tennis within the Olympic movement, which by then had itself become increasingly money-oriented.
Subject(s): Olympics, Tennis, Tennis--History
Department: Sport Science

Title: Effects of prolonged exposure to ethanol in vivo on functional parameters and sensitivity to nitrendipine in the isolated rat heart
Author(s): Leon J. Guppy (author), John M. Littleton (author)
Date: 1999
Abstract: This study investigated the possibility that previously reported marked upregulation of binding sites for the dihydropyridine calcium channel antagonist nitrendipine in heart tissue during the development of ethanol dependence in the rat may represent functional L-type voltage-operated calcium channels (L-VOCCs). Isolated hearts obtained from adult Sprague-Dawley rats, which received intoxicating concentrations of ethanol for 6-10 days, by inhalation, were perfused with Krebs-Henseleit solution in the Langendorff mode. Basic measurements of cardiac function were compared with hearts from control rats not exposed to ethanol vapor. In another study, concentration-response curves were constructed for nitrendipine at concentrations in the range of 10−10-10−6M for hearts obtained from control and ethanol-exposed animals. Changes in measured cardiac parameters such as R-wave amplitude, heart rate, diastolic and systolic pressure, and (+)dP/dtmax and coronary flow were recorded. All comparisons were made between preparations set to a similar left ventricular end-diastolic pressure. Under these conditions, there were no significant differences in R-wave amplitude, but isolated hearts from ethanol-dependent rats showed significantly greater indices of myocardial contraction than did controls. These included increased systolic and developed ventricular pressure and increased (+)dP/dtmax. Coronary flow also was significantly greater in hearts from ethanol-dependent rats compared with controls. Heart rate was higher in the alcohol-exposed group, but this difference did not achieve significance. When nitrendipine was added to the perfusate at concentrations between 10−10 and 10−6M, hearts from ethanol-dependent animals showed a greater sensitivity to the effects of the drug on heart rate and systolic pressure. Effects on R-wave amplitude and (+)dP/dtmax were less clear but also suggested a greater sensitivity to nitrendipine in hearts from ethanol-exposed rats. Effects on coronary flow were small and did not differ significantly between preparations from control and ethanol-dependent rats. The results suggest that the increase in Bmax of DHP binding previously observed in hearts from ethanol-dependent animals might represent an increase in L-VOCCs, which alters physiologic function, and pharmacologic responses in the isolated heart. These changes may represent the exposure of an adaptive mechanism designed to overcome the generally depressant effects of ethanol on cardiac function in vivo.
Department: Biology

Title: Lessons learned during establishment of the College of Health Sciences of the University of Zimbabwe 1995-2001
Author(s): Jacob Mufunda (author), Christopher Samkange (author), Lynette B. Sigola (author), Reginald Matchaba-Hove (author)
Date: 2017
Abstract: Background: The five year training of medical doctors has been conducted through the Faculty of Medicine of the University of Zimbabwe since 1963 in two physical sites in Harare; Mount Pleasant Campus for Basic Sciences and Mazowe Street Campus for Clinical Sciences. Annual student enrolment has gradually increased from less than 30 in the early stages to 200 currently. The continuing brain drain of doctors from the country necessitated the Government to instruct the Faculty of Medicine to double its student intake by enrolling a new student intake within three months to address this shortage. Methods: This descriptive longitudinal study is largely complemented by desk review and reflections from the authors who oversaw the evolution of the Faculty into the College. Authors experienced the transition of the institution over most of the study period and shared first-hand information. Results: Instruction from Government was used as an opportunity to develop. The Faculty of Medicine developed and began implementation of its inaugural five year strategic plan 1995-2001. The key tenets of the plan were to be a semi-autonomous institution (in relation to the University of Zimbabwe) comprising five Faculties with a designated teaching hospital under joint administration with Government where academicians were to receive similar emoluments. Clinicians were entitled to additional remuneration from Government for the clinical work delivered. The infrastructure was expanded to accommodate 200 medical students annually at the two sites. A government loan secured from the Spanish Protocol was used to purpose build the Health Sciences Building and equipment to accommodate and equip the five faculties. Discussion: The directive by Government to double medical student intake in order to address the doctor shortages was used as opportunity to address some of the Faculty of Medicine’s academic needs, including infrastructure, professional development and additional academic provisions in line with international trends. The realization of some of the outcomes is on course with the exception of ownership of a teaching hospital, autonomy of the College from the University and additional emoluments for clinicians from government, which are work in progress.
Subject(s): Health Education--Zimbabwe, Universities and colleges--Zimbabwe, Health Sciences, Hospitals--Zimbabwe, Medical Sciences--Zimbabwe
Department: Biology

Title

Rescue of placental phenotype in a mechanistic model of Beckwith-Wiedemann syndrome

Author(s)

Rosemary Oh-McGinnis (author), Aaron B. Bogutz (author), Kang Yun Lee (author), Michael J. Higgins (author), Louis Lefebvre (author)

Date

2010

Abstract

Background: Several imprinted genes have been implicated in the process of placentation. The distal region of mouse chromosome 7 (Chr 7) contains at least ten imprinted genes, several of which are expressed from the maternal homologue in the placenta. The corresponding paternal alleles of these genes are silenced in cis by an incompletely understood mechanism involving the formation of a repressive nuclear compartment mediated by the long noncoding RNA Kcnq1ot1 initiated from imprinting centre 2 (IC2). However, it is unknown whether some maternally expressed genes are silenced on the paternal homologue via a Kcnq1ot1-independent mechanism. We have previously reported that maternal inheritance of a large truncation of Chr7 encompassing the entire IC2-regulated domain (DelTel7 allele) leads to embryonic lethality at mid-gestation accompanied by severe placental abnormalities. Kcnq1ot1 expression can be abolished on the paternal chromosome by deleting IC2 (IC2KO allele). When the IC2KO mutation is paternally inherited, epigenetic silencing is lost in the region and the DelTel7 lethality is rescued in compound heterozygotes, leading to viable DelTel7/IC2KO mice.

Results: Considering the important functions of several IC2-regulated genes in placentation, we set out to determine whether these DelTel7/IC2KO rescued conceptuses develop normal placentae. We report no abnormalities with respect to the architecture and vasculature of the DelTel7/IC2KO rescued placentae. Imprinted expression of several of the IC2-regulated genes critical to placentation is also faithfully recapitulated in DelTel7/IC2KO placentae.

Conclusion: Taken together, our results demonstrate that all the distal chromosome 7 imprinted genes implicated in placental function are silenced by IC2 and Kcnq1ot1 on the paternal allele. Furthermore, our results demonstrate that the methylated maternal IC2 is not required for the regulation of nearby genes. The results show the potential for fully rescuing LQ trans placental abnormalities that are caused by imprinting defects. [ABSTRACT FROM AUTHOR]

Department

Biology