IDENTIFICATION AND CHARACTERIZATION OF SOCS44A IN DROSOPHILA

The JAK/STAT pathway is but one of the signal transduction cascades responsible for proper development and homeostasis. Gain-of-function mutations of pathway components are causative agents of several leukemias, highlighting the necessity for proper regulation of signal transduction. Drosophila presents an attractive model to study JAK/STAT signaling because mutations in the pathway behave in an analogous manner. Furthermore, the Drosophila cascade is much simpler as only one of each component required for activation has been characterized; whereas in mammals, there are many ligands, receptors, 4 JAKs and 7 STATs.Suppressors of Cytokine Signaling (SOCS) are one family of molecules which regulate JAK/STAT signaling via a negative feedback loop. All SOCS share a distinct modular domain architecture, which we exploited to locate three putative SOCS homologues within the Drosophila genome. I present the identification and initial characterization of one of these homologues, Socs44A. I show that Socs44A is not responsive to or dependent on JAK activity. However, I demonstrate that Socs44A is capable of downregulating JAK/STAT signaling in the developing wing but not inoogenesis, indicating that its ability to regulate the pathway is tissue specific, a phenomenon observed in the mammalian model.Signal transduction pathways are integrated at multiple levels. This interplay allows for combinatorial signaling, resulting in a higher order of complexity in the signals that can be received and interpreted by a cell. Well documented are the interactions between the JAK/STAT and the EGFR/MAPK pathways. In this work, I show that Socs44A can genetically interact with, and upregulate, the EGFR/MAPK pathway, analogous to a recent report involving SOCS-3.Starting with the Drosophila genome sequence, I initiated a reverse genetic approach to studying the function of the Socs44A locus. During the course of this investigation, I designed and implemented a novel post-processor of the BLAST algorithm, called Multi-BLAST, which facilitates retrieval of multiple domain sequences from public databases. In what would have been the ultimate achievement of this study, I attempted two mutagenesis screens designed to isolate Socs44A loss-of-function alleles. Progress on these screens is reported

Involvement of JAK/STAT Signaling and a Basement Membrane-Associated Protein during Air Sac Primordium Development in Drosophila Melanogaster

Tumor metastasis currently presents the greatest obstacle for effective cancer remediation. Metastatic growth necessitates both degradation of a specialized form of extracellular matrix (ECM) known as the basement membrane (BM) and the invasion of surrounding tissues thereafter. The thoracic air sacs of fruit flies (Drosophila melanogaster), which develop and operate in a fashion comparable to the human lung, provide a unique model for identifying and characterizing factors that contribute to its own development as well as tumoral invasion. We investigated the involvement of both Janus kinase (JAK)/Signal transducer and activator of transcription (STAT) signaling and a BMassociated protein during the development of air sac primordia (ASPs), the precursors to Drosophila air sacs. We find that JAK/STAT signaling occurs in ASP tip cells and that misexpression of core pathway components via the GAL4/UAS system negatively impacts ASP development. Further, we identify Unpaired 2 (Upd2) as the primary activating ligand for JAK/STAT activity in the ASP. Knockdown of the BM-associated protein using GAL4 drivers associated with a fibroblast growth factor (FGF) receptor gene, breathless (btl), and segment polarity gene, patched (ptc), prevented larval development beyond the second larval instar (L2). Knockdown of the BM-associated protein in the wing also produced bristle defects, but its overexpression did not have an effect anywhere other than in the ASP, where the proportion of mutant phenotypes increased significantly (p \u3c .0001) in response. Finally, we find that collagen IV localization was unaffected by knockdown of the BM-associated protein. Together, our data constitute a significant step forward in understanding the role of both this BM-associated protein and JAK/STAT signaling in the ASP and similar mammalian structures

The effect of an aquatic or land-based intervention programme on gross motor skills of selected children with Down syndrome

Thesis (MA)--Stellenbosch University, 2017.ENGLISH ABSTRACT: Children with Down Syndrome (DS) follow a unique pattern of motor development than neuro-typical children in their early years of development. They find it hard to acquire the movement skills that is expected of them and this leads to a possibility of leading a sedentary lifestyle during adolescence and later in life. According to researchers, an intervention program that focus on improving gross motor skills (GMS) can benefit children with DS tremendously. The primary aim of the study was to explore the effect of land and aquatic interventions over a 9-week period in children with DS to improve their GMS. The sample of convenience consisted of participants (N=31) between the age range of seven to 16 years, they were selected from four different schools in Somerset-West, Stellenbosch, Bellville and Mitchell’s Plain. The mentioned schools immediately showed interest in the study. Two schools participated in the land-based and the other two schools in the aquatic-based intervention program. The Bruininks-Oseretsky Test of Motor Proficiency (BOT-2) was used to assess the children’s gross motor skills to determine their strength and weaknesses. The BOT-2 assessed four composites, namely: fine manual control; manual coordination; body coordination; and strength and agility. The pre- and post-tests took two weeks to complete, whereas the aquatic- and land-based interventions were seven weeks long, with two, 40 minute sessions per week. The researcher compared the results of the aquatic and land programs. It was concluded that the land group’s GMS level was higher than the aquatic group at the pre- and post-tests. Both groups improved their overall score with the same amount of points and the researcher could, therefore, speculate that both intervention programs had an influence on their improvement. Both interventions could most likely be implemented at schools with learners that have special learning needs (SLN).AFRIKAANSE OPSOMMING: Kinders met Down Sindroom (DS) volg ’n unieke motoriese ontwikkelingspatroon tydens hulle ontwikkelingsjare in vergelyking met neuro-tipiese kinders. Kinders met DS vind dit baie moeilik om verwagte motoriesevaardighede teen ’n sekere ouderdom te bemeester, wat tot ’n moontlike sedentêre leefstyl gedurende adolessensie en in die latere lewe kan lei. Die implementering van ’n intervensieprogram wat daarop fokus om kinders se groot motoriese vaardighede (GMV) te verbeter kan volgens navorsers baie voordelig wees. Die primêre doel van hierdie studie was om te kyk wat die effek van land en water intervensies oor ’n 9-weke periode in kinders met DS sal wees om hulle GMV te verbeter. Die gerieflikheidsteekproef het uit deelnemers (N=31), tussen die ouderdom van sewe tot 16 bestaan, wat vanuit vier verskillende skole in Somerset-Wes, Stellenbosch, Bellville en Mitchell’s Plain geselekteer was. Genoemde skole het dadelik belangstelling in die studie getoon. Twee skole het deelgeneem aan die land-gebaseerde program en die ander twee aan die water-gebaseerde intervensieprogram. Die “Bruininks-Oseretsky Test of Motor Proficiency” (2005) (BOT-2) is gebruik, om die kinders se GMV tydens die studie te assesseer asook om hulle sterk- en swakpunte te bepaal. Die BOT-2 assesseer vier hoofareas: fyn motoriese beheer; fisiese koördinasie (manual coordination); liggaamskoördinasie; en krag en ratsheid. Voor- en na-toetse het elk twee weke geneem om te voltooi, die water- en land-gebaseerde intervensies was sewe weke lank met twee sessies per week, van 40 minute elk. Die navorser het die land en water programme se resultate vergelyk. Die gevolgtrekking was dat deelnemers in die land groep hoër getoets het met die voor- en na-toetse in hulle groot motoriese ontwikkeling in vergelyking met die water groep. Albei groepe het verbeteringe getoon in hulle algehele telling en daarom kon die navorser spekuleer dat die intervensieprogramme ʼn effek gehad het op hulle verbeteringe. Beide intervensies van hierdie studie kan heel moontlik by skole, met spesiale leer behoeftes geïmplementeer word.Master

THE EFFECTS OF GROSS-MOTOR FLUENCY TRAINING ON PHYSICAL ACTIVITY LEVELS IN YOUNG CHILDREN

Engaging in regular physical activity is one of the most important factors related to good health. Encouraging and promoting physical activity in young children aids in preventing overweight and obesity, promoting health, preventing disease, and supporting bone and overall growth development. However, physical activity levels in young children are low, and efficient and effective interventions to increase physical activity in young children are unclear. One creative method to increase physical activity in young children is gross-motor fluency training. A multielement single-case experimental design was employed to assess the effects of fluency training in six gross-motor skills on children’s levels of physical activity during free play sessions. Four typically developing preschool-aged children participated. Overall, results indicated that training skills relevant to two contexts (i.e., outdoor toys and open space) increased levels of moderate-to-vigorous physical activity (MVPA) for all four participants. Supplementary analyses suggested that fluency training increased three participant’s preferences for training play contexts, the effects of non-social reinforcement on MVPA increased for two participants following fluency training, and overall gross-motor competency increased for all four participants. Fluency-based instruction likely increased the proficiency, and decreased the response effort required for skill performance; enabled the participant’s to combine gross-motor component skills into composite chains; and facilitated generalization of gross-motor skills training to play. Fluency-based gross-motor instruction with young children represents a promising strategy to improve overall fitness levels, thereby increasing health and well-being and establishing a foundation for an active lifestyle. Keywords: physical activity, preschool, health, fluency training, gross-moto

Value of a physical education program for mentally retarded children

Physical activities are a vital element in the daily life of the retarded child at each level of his development, from the first movement of the infant to the coordinated movements required for participation in games and later vocational tasks. The purpose of the present study was to investigate the areas of motor, social and cognitive development as they are affected by physical activities and/or exercises. Secondly, the writer attempted to bring together lists of games, activities, equipment, records and movies to be used in working with retarded children

Morristown Montessori preschool

In many cases, a child\u27s first real contact with the built environment beyond the home is the preschool. This building type has been too often ignored in recent years. This thesis will explore how the built environment can engage a child and support his/her early education. I have chosen to explore these issues through the design investigation of a Montessori approach to early childhood education. I have investigated the design for this curricular approach because Montessori educational objectives, pedagogy, and focus are on nurturing and engaging the development of the child through active and independent involvement with his/her environment and are thus compatible with this thesis investigation

Rounding up the usual suspects: assessing Yorkie, AP-1, and stat coactivation in tumorigenesis

Can hyperactivation of a few key signaling effectors be the underlying reason for the majority of epithelial cancers despite different driver mutations? Here, to address this question, we use the Drosophila model, which allows analysis of gene expression from tumors with known initiating mutations. Furthermore, its simplified signaling pathways have numerous well characterized targets we can use as pathway readouts. In Drosophila tumor models, changes in the activities of three pathways, Jun N-terminal Kinase (JNK), Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT), and Hippo, mediated by AP-1 factors, Stat92E, and Yorkie, are reported frequently. We hypothesized this may indicate that these three pathways are commonly deregulated in tumors. To assess this, we mined the available transcriptomic data and evaluated the activity levels of eight pathways in various tumor models. Indeed, at least two out of our three suspects contribute to tumor development in all Drosophila cancer models assessed, despite different initiating mutations or tissues of origin. Surprisingly, we found that Notch signaling is also globally activated in all models examined. We propose that these four pathways, JNK, JAK/STAT, Hippo, and Notch, are paid special attention and assayed for systematically in existing and newly developed models

A kinase translocation reporter reveals real-time dynamics of ERK activity in Drosophila

Extracellular signal-regulated kinase (ERK) lies downstream of a core signalling cascade that controls all aspects of development and adult homeostasis. Recent developments have led to new tools to image and manipulate the pathway. However, visualising ERK activity in vivo with high temporal resolution remains a challenge in Drosophila. We adapted a kinase translocation reporter (KTR) for use in Drosophila, which shuttles out of the nucleus when phosphorylated by ERK. We show that ERK-KTR faithfully reports endogenous ERK signalling activity in developing and adult tissues, and that it responds to genetic perturbations upstream of ERK. Using ERK-KTR in time-lapse imaging, we made two novel observations: firstly, sustained hyperactivation of ERK by expression of dominant-active epidermal growth factor receptor raised the overall level but did not alter the kinetics of ERK activity; secondly, the direction of migration of retinal basal glia correlated with their ERK activity levels, suggesting an explanation for the heterogeneity in ERK activity observed in fixed tissue. Our results show that KTR technology can be applied in Drosophila to monitor ERK activity in real-time and suggest that this modular tool can be further adapted to study other kinases. This article has an associated First Person interview with the first author of the paper