A Hox gene mutation that triggers Nonsense-mediated RNA decay and affects alternative splicing during Drosophila development

Nonsense mutations are usually assumed to affect protein function by generating truncated protein products. Nonetheless, it is now clear that these mutations affect not just protein synthesis but also messenger RNA stability. The surveillance mechanism responsible for the detection and degradation of 'nonsense' RNA messages is termed nonsense-mediated RNA decay (NMD). Essential biochemical components of the NMD machinery have been defined in several species. Here we identify the Drosophila orthologue of one of these factors, Upf1, and document its expression during embryogenesis. To test whether NMD acts during Drosophila development, we make use of a mutation that introduces a stop codon into a variably spliced exon of the Hox gene Ultrabithorax (Ubx). Using real-time quantitative RT-PCR we demonstrate that Ubx transcripts containing the premature stop codon are expressed at lower levels than their wild type counterpart. Unexpectedly, we also find that the same mutation significantly increases the levels of a Ubx splicing isoform that lacks the exon containing the premature termination codon. These findings indicate that NMD is operational during Drosophila development and suggest that nonsense mutations may affect development by altering the spectrum of splicing products formed, as well as by reducing or eliminating protein synthesis

Stories in Motion: Integrating Creative Dance in a Language Arts Classroom

As learning gaps have widened in the wake of the COVID-19 pandemic, there has been an increased need for research-based strategies to improve student academic achievement and engagement. This study explored the integration of creative dance as a form of storytelling in a kindergarten language arts classroom. Students were introduced to an element of dance and used it to create short dance phrases in a unit on retelling. Both qualitative and quantitative data was collected using pre/post tests and student interviews measuring students’ engagement and enjoyment. Students involved in this study showed significant growth in their ability to orally retell a story (p \u3c .05) and analysis of student interviews suggested that students were highly engaged in the unit

Simulation of heat transfer efficiency for novel air cooling channels of a fuel cell bipolar plate / Wimi Akam

This study focused on designing and simulating a suitable air cooling for fuel cell bipolar plate with power rating of 3kW. For 3kW application, normally the fuel cells uses water as a medium to remove the heat generated. Instead of using water, air is to be used as a cooling medium. Simulation works are conducted to determine which design will gives the better result of heat transfer rate using air cooling. Two of the alternative design are zigzaged and inclined 2 degree channels. The lower the temperature at outlet will result in higher heat tansfer effeciency of the fuel cells. To obtain the result, two dimension steady state computational fluid dynamic analysis using two equation turbulence model ( k-c model). The work uses Star Design; an CFD software to estimate the temperature distribution at the surface of the bipolar plate. The result shows that design 2 which is having slightly inclined of 2 degree gives the most highest heat transfer rate

The European Court of Human Rights: achievements and challenges

Respect for human rights and fundamental freedom is anchored on the sanctity of life and dignity of man. It is an expression of equality of men. It is the core principle of the constitution of every democratic society. Today, the principles have been documented with solemn declaration and undertaking to respect and observe same at national, regional and world over. This work is limited to the European Court of Human Rights, its successes and failures and a call for reform to enhance its productivity in the attainment of the core objectives for which it was established in 1953.The research employs critical content analysis of relevant legislation. It found that the regional court system has enhanced respect for human rights in the region and calls for stiffer sanction for disobedience to the decision of the court.Keywords: European, court, human, human right

An anterior medial cell population with an apical-organ-like transcriptional profile that pioneers the central nervous system in the centipede Strigamia maritima.

The apical plate of primary marine larvae is characterized by a common set of transcription factors comprising six3, rx, hbn, nk2.1 and FoxQ2. It harbours the apical organ, a neural and ciliary structure with neurosecretory properties. Recent studies in lophotrochozoans have found that apical organ cells form the anterior tip of the developing central nervous system. We identify an anterior medial tissue in the embryonic centipede head that shares the transcriptional profile of the apical plate of marine larvae, including nested domains of FoxQ2 and six3 expression. This domain gives rise to an anterior medial population of neural precursors distinct from those arising within the segmental neuroectoderm. These medial cells do not express achaete scute homologue in proneural clusters, but express collier, a marker for post mitotic cells committed to a neural fate, while they are still situated in the surface ectodermal layer. They then sink under the surface to form a compact cell cluster. Once internalized these cells extend axons that pioneer the primary axonal scaffold of the central nervous system. The same cells express phc2, a neural specific prohormone convertase, which suggests that they form an early active neurosecretory centre. Some also express markers of hypothalamic neurons, including otp, vtn and vax1. These medial neurosecretory cells of the centipede are distinct from those of the pars intercerebralis, the anterior neurosecretory part of the insect brain. The pars intercerebralis derives from vsx positive placodal-like invagination sites. In the centipede, vsx expressing invaginating ectoderm is situated bilaterally adjacent to the medial pioneer cell population. Hence the pars intercerebralis is present in both insect and centipede brains, whereas no prominent anterior medial cluster of pioneer neurons is present in insects. These observations suggest that the arthropod brain retained ancestrally an anterior medial population of neurosecretory cells homologous to those of the apical plate in other invertebrate phyla, but that this cell population has been lost or greatly reduced in insects.OtherThis is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.ydbio.2014.09.02

The role of homeotic genes in the specification of the Drosophila gonad

AbstractBackground: In Drosophila, the gonads are composed of two cell populations: the germ line, derived from the pole cells, and a somatic component, derived from the mesoderm of abdominal segments 5–8. Formation of the gonad requires the function of a specific homeotic gene, abdominal-A (abd-A). Other genes of the bithorax complex, Ultrabithorax (Ubx) or Abdominal-B (Abd-B), cannot substitute for this requirement when abd-A is removed.Results We show here that, in embryos lacking the entire bithorax complex, experimentally induced expression of either ABD-A or UBX protein in the mesoderm will rescue the expression of a gonad-specific marker, 412 RNA. Ubiquitous expression of these homeotic proteins within the mesoderm results in the formation of ectopic gonad tissue anterior to the normal location of the gonads. In the absence of any endogenous bithorax-complex gene expression, however, mesoderm expressing gonad markers still condenses preferentially in the posterior segments of the abdomen, even in the absence of pole cells.Conclusion The specific requirement for abd-A and not Ubx in gonad development does not reflect differences in the properties of the proteins that these genes encode, but presumably reflects differences in their regulation. In normal development, the restriction of gonad formation to the posterior abdomen does not depend on the overlap of abd-A and Abd-B expression, but must depend on the regulation of abd-A and Ubx in the sub-population of the mesoderm that forms the gonad. Factors other than homeotic gene expression provide some cues that direct gonadal mesoderm to condense in the correct location

Odd-paired controls frequency doubling in Drosophila segmentation by altering the pair-rule gene regulatory network

The Drosophila embryo transiently exhibits a double-segment periodicity, defined by the expression of seven 'pair-rule' genes, each in a pattern of seven stripes. At gastrulation, interactions between the pair-rule genes lead to frequency doubling and the patterning of 14 parasegment boundaries. In contrast to earlier stages of Drosophila anteroposterior patterning, this transition is not well understood. By carefully analysing the spatiotemporal dynamics of pair-rule gene expression, we demonstrate that frequency-doubling is precipitated by multiple coordinated changes to the network of regulatory interactions between the pair-rule genes. We identify the broadly expressed but temporally patterned transcription factor, Odd-paired (Opa/Zic), as the cause of these changes, and show that the patterning of the even-numbered parasegment boundaries relies on Opa-dependent regulatory interactions. Our findings indicate that the pair-rule gene regulatory network has a temporally modulated topology, permitting the pair-rule genes to play stage-specific patterning roles.This work was supported by a BBSRC PhD studentship to Erik Clark

Saskatchewan youth in care: Exploring the perceived role of attachment in fostering resilience

Growing numbers of children in youth are in out-of-home care, and the complexity of the challenges and outcomes they face is an issue that continues to require attention. In Canada, the overrepresentation of indigenous youth in out-of-home care has been identified as an important issue needing to be addressed as a priority. A significant portion of the literature examines risk factors and negative outcomes, with resiliency only more recently becoming an area of focus. This narrative study examines the lived experiences of 6 individuals with varying involvement in the child-welfare system and their perspectives on how to foster resilience in children in youth experiencing out-of-home care. In depth interviews were conducted to explore the overarching questions of what role attachment might play in fostering resilience in this demographic. Sub questions explored other factors that may also contribute to this goal. Findings indicate that central to supporting and fostering resilience in children and youth is the role of relationships. Subthemes identified role of values, and need for increased supports and understanding. Implications of these findings extend beyond the child and indicate a need to consider the systems surrounding the child. The child’s resilience is influenced greatly by surrounding support systems and how those function, such as the foster parent, the biological family, and the child welfare system. Just as the needs of children and youth in out-of-home care are complex and diverse, so are the ways we can better support this demographic and those who play critical roles in helping foster resilience in them

Formation and subdivision of the head field in the centipede Strigamia maritima, as revealed by the expression of head gap gene orthologues and hedgehog dynamics.

Background There have been few studies of head patterning in non-insect arthropods, and even in the insects, much is not yet understood. In the fly Drosophila three head gap genes, orthodenticle (otd), buttonhead (btd) and empty spiracles (ems) are essential for patterning the head. However, they do not act through the same pair-rule genes that pattern the trunk from the mandibular segment backwards. Instead they act through the downstream factors collier (col) and cap‘n’collar (cnc), and presumably other unknown factors. In the beetle Tribolium, these same gap and downstream genes are also expressed during early head development, but in more restricted domains, and some of them have been shown to be of minor functional importance. In the spider Parasteatoda tepidariorum, hedgehog (hh) and otd have been shown to play an important role in head segmentation. Results We have investigated the expression dynamics of otx (otd), SP5/btd, ems, and the downstream factors col, cnc and hh during early head development of the centipede Strigamia maritima. Our results reveal the process of head condensation and show that the anteroposterior sequence of specific gene expression is conserved with that in insects. SP5/btd and otx genes are expressed prior to and during head field formation, whereas ems is not expressed until after the initial formation of the head field, in an emerging gap between SP5/btd and otx expression. Furthermore, we observe an early domain of Strigamia hh expression in the head field that splits to produce segmental stripes in the ocular, antennal and intercalary segments. Conclusions The dynamics of early gene expression in the centipede show considerable similarity with that in the beetle, both showing more localised expression of head gap genes than occurs in the fly. This suggests that the broad overlapping domains of head gap genes observed in Drosophila are derived in this lineage. We also suggest that the splitting of the early hh segmental stripes may reflect an ancestral and conserved process in arthropod head patterning. A remarkably similar stripe splitting process has been described in a spider, and in the Drosophila head hh expression starts from a broad domain that transforms into three stripes