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• 1. [Article] Fostering Self-Regulation in Online Learning in K-12 Education

  Current educational trends identify self-regulation as an essential skill for today’s K-12 students. Online learning environments provide a unique opportunity for teachers to use the various features to ...

  Citation × Citation Citation Abstract Copy Title: Fostering Self-Regulation in Online Learning in K-12 Education Author: Lock, Jennifer, Eaton, Sarah Elaine, Kessy, Elaine Year: 2017 Current educational trends identify self-regulation as an essential skill for today’s K-12 students. Online learning environments provide a unique opportunity for teachers to use the various features to cultivate student self-regulation. Through a review of the literature, self-regulation has been defined and key strategies have been identified that support self-regulated learning in online learning environments. Course design, goal setting and orientation, self-efficacy, scaffolding, and reflection are identified as key factors that foster student self-regulated learning skills. The article concludes with implications for teacher education. Title: Fostering Self-Regulation in Online Learning in K-12 Education Author: Lock, Jennifer, Eaton, Sarah Elaine, Kessy, Elaine Year: 2017 Current educational trends identify self-regulation as an essential skill for today’s K-12 students. Online learning environments provide a unique opportunity for teachers to use the various features to cultivate student self-regulation. Through a review of the literature, self-regulation has been defined and key strategies have been identified that support self-regulated learning in online learning environments. Course design, goal setting and orientation, self-efficacy, scaffolding, and reflection are identified as key factors that foster student self-regulated learning skills. The article concludes with implications for teacher education. Close

• 2. [Article] Scaffolding the Development of Early Self-Regulation: The Role of Structure and Routine in Children's Daily Activities

  Learning to self-regulate one's behavior is a core developmental task in early childhood. Regulation of behavior is a challenge for young children largely due to cognitive constraints, specifically in ...

  Citation × Citation Citation Abstract Copy Title: Scaffolding the Development of Early Self-Regulation: The Role of Structure and Routine in Children's Daily Activities Author: Taylor, Cynthia Lynn Year: 2011 Learning to self-regulate one's behavior is a core developmental task in early childhood. Regulation of behavior is a challenge for young children largely due to cognitive constraints, specifically in the areas of attention and memory. As such, it has been theorized that both caregivers and a child's environment can support the development of behavioral self-regulation by providing cues as to what constitutes acceptable behavior in any given context. Although much research has been conducted on the role caregivers play in this regard, little is known about how a child's environment may also serve to support emerging self-regulation of behavior. The present study sought to identify differences among children's daily activities in terms of their degree of structure and routine and how they related to changes in patterns of self-regulated behavior over time. Twenty-one children ages 6 to 60 months in three age-graded classrooms at a constructivist child-care center were video-taped at three measurement points over a six-month period as they engaged in a variety of daily activities (i.e., free play, meals and clean-up). Trained observers coded for nine self-regulatory behaviors and the daily activities during which they occurred. It was hypothesized that structured and routine daily activities would scaffold the development of self-regulation and internalization such that these behaviors would occur more frequently during activities high in structure and routine. Over time, practice during activities that are high and low in structure and routine should support self-regulated behavior in the absence of structure and routine as well. Overall, results demonstrated that in the presence of environmental cues for expected behavior (i.e., structure and routine) children tend to engage in more self-regulated behavior than in the absence of such cues. Title: Scaffolding the Development of Early Self-Regulation: The Role of Structure and Routine in Children's Daily Activities Author: Taylor, Cynthia Lynn Year: 2011 Learning to self-regulate one's behavior is a core developmental task in early childhood. Regulation of behavior is a challenge for young children largely due to cognitive constraints, specifically in the areas of attention and memory. As such, it has been theorized that both caregivers and a child's environment can support the development of behavioral self-regulation by providing cues as to what constitutes acceptable behavior in any given context. Although much research has been conducted on the role caregivers play in this regard, little is known about how a child's environment may also serve to support emerging self-regulation of behavior. The present study sought to identify differences among children's daily activities in terms of their degree of structure and routine and how they related to changes in patterns of self-regulated behavior over time. Twenty-one children ages 6 to 60 months in three age-graded classrooms at a constructivist child-care center were video-taped at three measurement points over a six-month period as they engaged in a variety of daily activities (i.e., free play, meals and clean-up). Trained observers coded for nine self-regulatory behaviors and the daily activities during which they occurred. It was hypothesized that structured and routine daily activities would scaffold the development of self-regulation and internalization such that these behaviors would occur more frequently during activities high in structure and routine. Over time, practice during activities that are high and low in structure and routine should support self-regulated behavior in the absence of structure and routine as well. Overall, results demonstrated that in the presence of environmental cues for expected behavior (i.e., structure and routine) children tend to engage in more self-regulated behavior than in the absence of such cues. Close

• 3. [Article] Growth Phase-Dependent Gene Regulation in Vivo in Sulfolobus Solfataricus

  Ribosomal genes are strongly regulated dependent on growth phase in all organisms, but this regulation is poorly understood in Archaea. Moreover, very little is known about growth phase-dependent gene ...

  Citation × Citation Citation Abstract Copy Title: Growth Phase-Dependent Gene Regulation in Vivo in Sulfolobus Solfataricus Author: DeYoung, Melissa, Thayer, Michelle, Van der Oost, John, Stedman, Kenneth M. Year: 2011 Ribosomal genes are strongly regulated dependent on growth phase in all organisms, but this regulation is poorly understood in Archaea. Moreover, very little is known about growth phase-dependent gene regulation in Archaea. SSV1- based lacS reporter gene constructs containing the Sulfolobus 16S/23S rRNA gene core promoter, the TF55a core promoter, or the native lacS promoter were tested in Sulfolobus solfataricus cells lacking the lacS gene. The 42-bp 16S/23S rRNA gene and 39-bp TF55a core promoters are sufficient for gene expression in S. solfataricus. However, only gene expression driven by the 16S/23S rRNA gene core promoter is dependent on the culture growth phase. This is the smallest known regulated promoter in Sulfolobus. To our knowledge, this is the first study to show growth phase-dependent rRNA gene regulation in Archaea. Title: Growth Phase-Dependent Gene Regulation in Vivo in Sulfolobus Solfataricus Author: DeYoung, Melissa, Thayer, Michelle, Van der Oost, John, Stedman, Kenneth M. Year: 2011 Ribosomal genes are strongly regulated dependent on growth phase in all organisms, but this regulation is poorly understood in Archaea. Moreover, very little is known about growth phase-dependent gene regulation in Archaea. SSV1- based lacS reporter gene constructs containing the Sulfolobus 16S/23S rRNA gene core promoter, the TF55a core promoter, or the native lacS promoter were tested in Sulfolobus solfataricus cells lacking the lacS gene. The 42-bp 16S/23S rRNA gene and 39-bp TF55a core promoters are sufficient for gene expression in S. solfataricus. However, only gene expression driven by the 16S/23S rRNA gene core promoter is dependent on the culture growth phase. This is the smallest known regulated promoter in Sulfolobus. To our knowledge, this is the first study to show growth phase-dependent rRNA gene regulation in Archaea. Close

• 4. [Article] Review: Is Parent–Child Attachment a Correlate of Children’s Emotion Regulation and Coping?

  Attachment theorists have described the parent–child attachment relationship as a foundation for the emergence and development of children’s capacity for emotion regulation and coping with stress. The ...

  Citation × Citation Citation Abstract Copy Title: Review: Is Parent–Child Attachment a Correlate of Children’s Emotion Regulation and Coping? Author: Zimmer-Gembeck, Melanie J., Webb, Haley J., Pepping, Christopher A., Swan, Kellie, Merlo, Ourania, Skinner, Ellen A., Avdagic, Elbina, Dunbar, Michelle Year: 2017 Attachment theorists have described the parent–child attachment relationship as a foundation for the emergence and development of children’s capacity for emotion regulation and coping with stress. The purpose of this review was to summarize the existing research addressing this issue. We identified 23 studies that employed validated assessments of attachment, which were not based on self-report questionnaires, and separated the summary into findings for toddlers/preschool, children, and adolescents. Although most associations were weak and only a minority of the multiple possible associations tested was supported in each study, all studies (but one) reported at least one significant association between attachment and emotion regulation or coping. The evidence pointed to the regulatory and coping problems of toddlers showing signs of ambivalent attachment or the benefits of secure (relative to insecure) attachment for toddlers, children, and adolescents. Toddlers who showed signs of avoidant attachment relied more on self-related regulation (or less social-oriented regulation and coping), but it was not clear whether these responses were maladaptive. There was little information available regarding associations of ambivalent attachment with school-age children’s or adolescents’ emotion regulation. There were also few studies that assessed disorganized attachment. Title: Review: Is Parent–Child Attachment a Correlate of Children’s Emotion Regulation and Coping? Author: Zimmer-Gembeck, Melanie J., Webb, Haley J., Pepping, Christopher A., Swan, Kellie, Merlo, Ourania, Skinner, Ellen A., Avdagic, Elbina, Dunbar, Michelle Year: 2017 Attachment theorists have described the parent–child attachment relationship as a foundation for the emergence and development of children’s capacity for emotion regulation and coping with stress. The purpose of this review was to summarize the existing research addressing this issue. We identified 23 studies that employed validated assessments of attachment, which were not based on self-report questionnaires, and separated the summary into findings for toddlers/preschool, children, and adolescents. Although most associations were weak and only a minority of the multiple possible associations tested was supported in each study, all studies (but one) reported at least one significant association between attachment and emotion regulation or coping. The evidence pointed to the regulatory and coping problems of toddlers showing signs of ambivalent attachment or the benefits of secure (relative to insecure) attachment for toddlers, children, and adolescents. Toddlers who showed signs of avoidant attachment relied more on self-related regulation (or less social-oriented regulation and coping), but it was not clear whether these responses were maladaptive. There was little information available regarding associations of ambivalent attachment with school-age children’s or adolescents’ emotion regulation. There were also few studies that assessed disorganized attachment. Close

• 5. [Article] Power Self-Regulation in Double-Pass High-Gain Laser Amplifiers

  Double-pass laser amplifiers can provide automatic passive regulation of the power in an optical signal. This regulation can significantly reduce the amplitude noise on a laser beam that is intended as ...

  Citation × Citation Citation Abstract Copy Title: Power Self-Regulation in Double-Pass High-Gain Laser Amplifiers Author: Casperson, Lee W., Casperson, Janet M. Year: 2000 Double-pass laser amplifiers can provide automatic passive regulation of the power in an optical signal. This regulation can significantly reduce the amplitude noise on a laser beam that is intended as a continuous wave light source. Analytic expressions are derived to describe the optical-noise-reduction region of double-pass amplifier operation and the dependence of the self-regulation properties on gain, saturation, and mirror reflectivity. Title: Power Self-Regulation in Double-Pass High-Gain Laser Amplifiers Author: Casperson, Lee W., Casperson, Janet M. Year: 2000 Double-pass laser amplifiers can provide automatic passive regulation of the power in an optical signal. This regulation can significantly reduce the amplitude noise on a laser beam that is intended as a continuous wave light source. Analytic expressions are derived to describe the optical-noise-reduction region of double-pass amplifier operation and the dependence of the self-regulation properties on gain, saturation, and mirror reflectivity. Close

• 6. [Article] The Cul3 Ubiquitin Ligase: An Essential Regulator of Diverse Cellular Processes

  Cul3 forms E3 ubiquitin ligase complexes that regulate a variety of cellular processes. This dissertation describes Cul3‘s role in several of these pathways and provides new mechanistic details regarding ...

  Citation × Citation Citation Abstract Copy Title: The Cul3 Ubiquitin Ligase: An Essential Regulator of Diverse Cellular Processes Author: Davidge, Brittney Marie Year: 2017 Cul3 forms E3 ubiquitin ligase complexes that regulate a variety of cellular processes. This dissertation describes Cul3‘s role in several of these pathways and provides new mechanistic details regarding the role of Cul3 in eukaryotic cells. Cyclin E is an example of a protein that is regulated in a Cul3-dependent manner. Cyclin E is a cell cycle regulator that controls the beginning of DNA replication in mammalian cells. Increased levels of cyclin E are found in some cancers, in addition, proteolytic removal of the cyclin E N-terminus occurs in some cancers and is associated with tumorigenesis. Cyclin E levels are tightly regulated and controlled in part through ubiquitin-mediated degradation initiated by one of two E3 ligase complexes, Cul1 and Cul3. Cul1 mediated degradation of cyclin E is triggered by cyclin E phosphorylation, however the mechanism Cul3 uses to ubiquitinate cyclin E is poorly understood. In order to gain a better understanding of how Cul3 mediates cyclin E destruction we identified the degron on cyclin E that is important in Cul3 dependent degradation. In addition, we show this degron is lacking in LMW cyclin E (found in abundance in breast cancer), providing a novel mechanism for how these cyclin E modifications result in increased cyclin E levels by avoiding the Cul3 degradation pathway. Title: The Cul3 Ubiquitin Ligase: An Essential Regulator of Diverse Cellular Processes Author: Davidge, Brittney Marie Year: 2017 Cul3 forms E3 ubiquitin ligase complexes that regulate a variety of cellular processes. This dissertation describes Cul3‘s role in several of these pathways and provides new mechanistic details regarding the role of Cul3 in eukaryotic cells. Cyclin E is an example of a protein that is regulated in a Cul3-dependent manner. Cyclin E is a cell cycle regulator that controls the beginning of DNA replication in mammalian cells. Increased levels of cyclin E are found in some cancers, in addition, proteolytic removal of the cyclin E N-terminus occurs in some cancers and is associated with tumorigenesis. Cyclin E levels are tightly regulated and controlled in part through ubiquitin-mediated degradation initiated by one of two E3 ligase complexes, Cul1 and Cul3. Cul1 mediated degradation of cyclin E is triggered by cyclin E phosphorylation, however the mechanism Cul3 uses to ubiquitinate cyclin E is poorly understood. In order to gain a better understanding of how Cul3 mediates cyclin E destruction we identified the degron on cyclin E that is important in Cul3 dependent degradation. In addition, we show this degron is lacking in LMW cyclin E (found in abundance in breast cancer), providing a novel mechanism for how these cyclin E modifications result in increased cyclin E levels by avoiding the Cul3 degradation pathway. Close

• 7. [Article] The Effects of Airline Deregulation on Airline Safety: An Econometric Analysis

  After an unfortunate series of accidents in the mid 1930’s the Air Transport Association (ATA) lobbied Congress for regulation of the industry. The ATA claimed that unfair competition was endangering the ...

  Citation × Citation Citation Abstract Copy Title: The Effects of Airline Deregulation on Airline Safety: An Econometric Analysis Author: De Jager, William Charles Year: 1993 After an unfortunate series of accidents in the mid 1930’s the Air Transport Association (ATA) lobbied Congress for regulation of the industry. The ATA claimed that unfair competition was endangering the public safety. The Civil Aeronautics Act of 1938 created the Civil Aeronautics Board (CAB) and gave the CAB the authority to regulate the industry. During the regulation era airline ridership increased and safety improved. During the regulation period, opportunity for comparing the safety record of the regulated industry with the record of the unregulated portions of the industry was limited. The few attempts made rendered inconclusive results. During a period of high inflation and high interest rates in the 1970’s interest in deregulating the airlines arose. With passage of the Airline Deregulation Act of 1978, interest in the effects of regulation on airline safety was renewed. More than a decade has passed since deregulation. The industry has continued to improve its safety record during the deregulation period. The question remains: "How has deregulation affected airline safety?" In this study records of airline accidents and incidents investigated by the National Transportation Safety Board are examined. The occurrences are divided into those with causes that are under the airlines control and those that are not under their control. Those under the airlines control are regressed against time and a dummy variable for deregulation. The possible effects of airline profitability on the results are also explored. The results indicate that deregulation had an adverse effect on airline safety. The effects of alternative formulations are also examined. The effect though statistically significant is small. It does not suggest the need to return to a regulated airline industry. But, it does suggest the need for additional research into the connection between airline safety and competition. Title: The Effects of Airline Deregulation on Airline Safety: An Econometric Analysis Author: De Jager, William Charles Year: 1993 After an unfortunate series of accidents in the mid 1930’s the Air Transport Association (ATA) lobbied Congress for regulation of the industry. The ATA claimed that unfair competition was endangering the public safety. The Civil Aeronautics Act of 1938 created the Civil Aeronautics Board (CAB) and gave the CAB the authority to regulate the industry. During the regulation era airline ridership increased and safety improved. During the regulation period, opportunity for comparing the safety record of the regulated industry with the record of the unregulated portions of the industry was limited. The few attempts made rendered inconclusive results. During a period of high inflation and high interest rates in the 1970’s interest in deregulating the airlines arose. With passage of the Airline Deregulation Act of 1978, interest in the effects of regulation on airline safety was renewed. More than a decade has passed since deregulation. The industry has continued to improve its safety record during the deregulation period. The question remains: "How has deregulation affected airline safety?" In this study records of airline accidents and incidents investigated by the National Transportation Safety Board are examined. The occurrences are divided into those with causes that are under the airlines control and those that are not under their control. Those under the airlines control are regressed against time and a dummy variable for deregulation. The possible effects of airline profitability on the results are also explored. The results indicate that deregulation had an adverse effect on airline safety. The effects of alternative formulations are also examined. The effect though statistically significant is small. It does not suggest the need to return to a regulated airline industry. But, it does suggest the need for additional research into the connection between airline safety and competition. Close

• 8. [Article] Parking Regulation and Land Use in the Portland Metropolitan Region: A Case for Local Parking Districts and Shared Parking Arrangements

  The purpose of this paper is to examine parking regulations and parking management in a land-use and transportation planning context. Current parking management policies in the Portland metropolitan region ...

  Citation × Citation Citation Abstract Copy Title: Parking Regulation and Land Use in the Portland Metropolitan Region: A Case for Local Parking Districts and Shared Parking Arrangements Author: Engstrom, Eric Year: 1996 The purpose of this paper is to examine parking regulations and parking management in a land-use and transportation planning context. Current parking management policies in the Portland metropolitan region provide the overall framework for this analysis. The paper is divided into six sections: • Section one provides a summary of the planning policies and growth management strategies of the Portland metropolitan region which impact par king policy. These policies provide the context for the current discussion of parking regulations in the region. • The experiences of two close-in Portland neighborhoods are discussed in section two. Parking is not regulated by the city zoning code in these neighborhoods. Lessons learned from these areas provide important case studies if existing parking regulations are to be re-considered. • Section three includes a description of how parking outside of the downtown area is regulated by the City of Portland's zoning code, and examines several problems with this approach. • The geography and spatial layout of parking is explored in section four. This section examines how existing private parking development patterns might be converted to a different parking pattern. Different approaches to parking may be necessary with different development patterns. • Section five examines the characteristics of common goods and services to provide a theoretical basis for considering par king as an element of the public infrastructure. • Section six outlines a model for establishing a different approach to parking policy, one which emphasizes shared parking and neighborhood parking districts rather than zoning code regulation. Title: Parking Regulation and Land Use in the Portland Metropolitan Region: A Case for Local Parking Districts and Shared Parking Arrangements Author: Engstrom, Eric Year: 1996 The purpose of this paper is to examine parking regulations and parking management in a land-use and transportation planning context. Current parking management policies in the Portland metropolitan region provide the overall framework for this analysis. The paper is divided into six sections: • Section one provides a summary of the planning policies and growth management strategies of the Portland metropolitan region which impact par king policy. These policies provide the context for the current discussion of parking regulations in the region. • The experiences of two close-in Portland neighborhoods are discussed in section two. Parking is not regulated by the city zoning code in these neighborhoods. Lessons learned from these areas provide important case studies if existing parking regulations are to be re-considered. • Section three includes a description of how parking outside of the downtown area is regulated by the City of Portland's zoning code, and examines several problems with this approach. • The geography and spatial layout of parking is explored in section four. This section examines how existing private parking development patterns might be converted to a different parking pattern. Different approaches to parking may be necessary with different development patterns. • Section five examines the characteristics of common goods and services to provide a theoretical basis for considering par king as an element of the public infrastructure. • Section six outlines a model for establishing a different approach to parking policy, one which emphasizes shared parking and neighborhood parking districts rather than zoning code regulation. Close

• 9. [Article] Transcriptomic Regulation of Alternative Phenotypic Trajectories in Embryos of the Annual Killifish <i>Austrofundulus limnaeus</i>

  The Annual Killifish, Austrofundulus limnaeus, survives the seasonal drying of their pond habitat in the form of embryos entering diapause midway through development. The diapause trajectory is one of ...

  Citation × Citation Citation Abstract Copy Title: Transcriptomic Regulation of Alternative Phenotypic Trajectories in Embryos of the Annual Killifish <i>Austrofundulus limnaeus</i> Author: Romney, Amie Lynn Thomas Year: 2017 The Annual Killifish, Austrofundulus limnaeus, survives the seasonal drying of their pond habitat in the form of embryos entering diapause midway through development. The diapause trajectory is one of two developmental phenotypes. Alternatively, individuals can "escape" entry into diapause and develop continuously until hatching. The alternative phenotypes of A. limnaeus are a form of developmental plasticity that provides this species with a physiological adaption for surviving stressful environments. The developmental trajectory of an embryo is not distinguishable morphologically upon fertilization and phenotype is believed to be influenced by maternal provisioning within the egg based on observations of offspring phenotype production. However, incubation temperature may override any such maternal pattern suggesting an environmental influence on the regulation of developmental trajectory. We hypothesize that maternally packaged gene products coordinate the cellular events prior to the maternal-to-zygotic transition (MTZ) that determine developmental trajectory in embryos of A. limnaeus. In addition, we propose that environmentally responsive gene expression after the MTZ can sustain or override any such maternal provisioning. Using high-throughput RNA-sequencing, we have generated transcriptomic profiles of protein-coding messenger RNA and noncoding RNA during development in A. limnaeus. Embryos destined for either the diapause or escape phenotypes display unique expression profiles immediately upon fertilization that support hormone synthesis, well before the stage when phenotypes are morphologically distinct. At stages when the trajectories diverge from one another, differential expression of the vitamin D receptor signaling pathway suggests that vitamin D signaling may be a key regulator of developmental phenotype in this species. These data provide a critical link between maternal and environmental influences on the genetic regulation of phenotypic plasticity. These results will not only impact our understanding of the genetic mechanisms that regulate entrance into diapause, but also provide insight into the epigenetic regulation of gene expression and development. Uncovering genetic mechanisms in a system exhibiting alternative developmental trajectories will elucidate the role of maternal packaging in regulating developmental decisions, and in sustaining metabolic depression during diapause. Title: Transcriptomic Regulation of Alternative Phenotypic Trajectories in Embryos of the Annual Killifish <i>Austrofundulus limnaeus</i> Author: Romney, Amie Lynn Thomas Year: 2017 The Annual Killifish, Austrofundulus limnaeus, survives the seasonal drying of their pond habitat in the form of embryos entering diapause midway through development. The diapause trajectory is one of two developmental phenotypes. Alternatively, individuals can "escape" entry into diapause and develop continuously until hatching. The alternative phenotypes of A. limnaeus are a form of developmental plasticity that provides this species with a physiological adaption for surviving stressful environments. The developmental trajectory of an embryo is not distinguishable morphologically upon fertilization and phenotype is believed to be influenced by maternal provisioning within the egg based on observations of offspring phenotype production. However, incubation temperature may override any such maternal pattern suggesting an environmental influence on the regulation of developmental trajectory. We hypothesize that maternally packaged gene products coordinate the cellular events prior to the maternal-to-zygotic transition (MTZ) that determine developmental trajectory in embryos of A. limnaeus. In addition, we propose that environmentally responsive gene expression after the MTZ can sustain or override any such maternal provisioning. Using high-throughput RNA-sequencing, we have generated transcriptomic profiles of protein-coding messenger RNA and noncoding RNA during development in A. limnaeus. Embryos destined for either the diapause or escape phenotypes display unique expression profiles immediately upon fertilization that support hormone synthesis, well before the stage when phenotypes are morphologically distinct. At stages when the trajectories diverge from one another, differential expression of the vitamin D receptor signaling pathway suggests that vitamin D signaling may be a key regulator of developmental phenotype in this species. These data provide a critical link between maternal and environmental influences on the genetic regulation of phenotypic plasticity. These results will not only impact our understanding of the genetic mechanisms that regulate entrance into diapause, but also provide insight into the epigenetic regulation of gene expression and development. Uncovering genetic mechanisms in a system exhibiting alternative developmental trajectories will elucidate the role of maternal packaging in regulating developmental decisions, and in sustaining metabolic depression during diapause. Close

• 10. [Article] Genomic and Hormonal Components of Altered Developmental Pathways in the Annual Killifish, Austrofundulus limnaeus

  The annual killifish, Austrofundulus limnaeus, may enter embryonic diapause at three distinct points of development, termed diapause I, II, and III. Previous studies suggest a role for steroid hormones ...

  Citation × Citation Citation Abstract Copy Title: Genomic and Hormonal Components of Altered Developmental Pathways in the Annual Killifish, Austrofundulus limnaeus Author: Pri-Tal, Benjamin M. Year: 2010 The annual killifish, Austrofundulus limnaeus, may enter embryonic diapause at three distinct points of development, termed diapause I, II, and III. Previous studies suggest a role for steroid hormones in the regulation of diapause in annual killifish. This study concerns the hormonal and genomic components involved in the developmental decision to enter or escape diapause II from both a maternal and embryonic perspective. Steroid hormone levels were measured in tissues isolated from adult female fish that were producing either high or low proportions of escape embryos. Levels of steroid hormones were also measured in new fertilized embryos that were known to be on either an escape or diapausing developmental trajectory. In addition, cDNA microarray gene expression analysis was used to identify gene sequences that may be associated with the regulation of entry into diapause in this species. Decreases in maternal estrogen levels associated with aging are correlated with decreasing escape embryo production, but there is no direct association between measured steroid hormone levels and escape embryo production. However, maternal production of escape embryos is correlated with increased ratios of 17 ß-estradiol to testosterone in ovary tissue, and cDNA microarray gene expression analysis indicates differentially regulated sequences associated with escape embryo production in maternal tissues. Both of these independent measures suggest hormonal involvement in the regulation of diapause. Embryonic levels of steroid hormones in newly fertilized embryos are not correlated with entry or escape from diapause II, although incubation in exogenous cortisol and 17 ß-estradiol causes an increase in the proportion of escape embryos. Gene expression analysis again suggests hormonal involvement. Interestingly, genes involved in epigenetic control of gene expression though chromatin condensation are differentially regulated in both maternal tissues producing escape embryos, and in embryos on the different developmental trajectories. These data suggest that hormonal control of gene expression through alterations of chromatin condensation may regulate the decision to enter or escape diapause II. Title: Genomic and Hormonal Components of Altered Developmental Pathways in the Annual Killifish, Austrofundulus limnaeus Author: Pri-Tal, Benjamin M. Year: 2010 The annual killifish, Austrofundulus limnaeus, may enter embryonic diapause at three distinct points of development, termed diapause I, II, and III. Previous studies suggest a role for steroid hormones in the regulation of diapause in annual killifish. This study concerns the hormonal and genomic components involved in the developmental decision to enter or escape diapause II from both a maternal and embryonic perspective. Steroid hormone levels were measured in tissues isolated from adult female fish that were producing either high or low proportions of escape embryos. Levels of steroid hormones were also measured in new fertilized embryos that were known to be on either an escape or diapausing developmental trajectory. In addition, cDNA microarray gene expression analysis was used to identify gene sequences that may be associated with the regulation of entry into diapause in this species. Decreases in maternal estrogen levels associated with aging are correlated with decreasing escape embryo production, but there is no direct association between measured steroid hormone levels and escape embryo production. However, maternal production of escape embryos is correlated with increased ratios of 17 ß-estradiol to testosterone in ovary tissue, and cDNA microarray gene expression analysis indicates differentially regulated sequences associated with escape embryo production in maternal tissues. Both of these independent measures suggest hormonal involvement in the regulation of diapause. Embryonic levels of steroid hormones in newly fertilized embryos are not correlated with entry or escape from diapause II, although incubation in exogenous cortisol and 17 ß-estradiol causes an increase in the proportion of escape embryos. Gene expression analysis again suggests hormonal involvement. Interestingly, genes involved in epigenetic control of gene expression though chromatin condensation are differentially regulated in both maternal tissues producing escape embryos, and in embryos on the different developmental trajectories. These data suggest that hormonal control of gene expression through alterations of chromatin condensation may regulate the decision to enter or escape diapause II. Close