Mcrs1 interacts with Six1 to influence early craniofacial and otic development.

The Six1 transcription factor plays a major role in craniofacial development. Mutations in SIX1 and its co-factor, EYA1, are causative for about 50% of Branchio-otic/Branchio-oto-renal syndrome (BOR) patients, who are characterized by variable craniofacial, otic and renal malformations. We previously screened for other proteins that might interact with Six1 to identify additional genes that may play a role in BOR, and herein characterize the developmental role of one of them, Microspherule protein 1 (Mcrs1). We found that in cultured cells, Mcrs1 bound to Six1 and in both cultured cells and embryonic ectoderm reduced Six1-Eya1 transcriptional activation. Knock-down of Mcrs1 in embryos caused an expansion of the domains of neural plate genes and two genes expressed in both the neural plate and neural crest (zic1, zic2). In contrast, two other genes expressed in pre-migratory neural crest (foxd3, sox9) were primarily reduced. Cranial placode genes showed a mixture of expanded and diminished expression domains. At larval stages, loss of Mcrs1 resulted in a significant reduction of otic vesicle gene expression concomitant with a smaller otic vesicle volume. Experimentally increasing Mcrs1 above endogenous levels favored the expansion of neural border and neural crest gene domains over cranial placode genes; it also reduced otic vesicle gene expression but not otic vesicle volume. Co-expression of Mcrs1 and Six1 as well as double knock-down and rescue experiments establish a functional interaction between Mcrs1 and Six1 in the embryo, and demonstrate that this interaction has an important role in the development of craniofacial tissues including the otic vesicle.

From CREATE Workshop to Course Implementation: Examining Downstream Impacts on Teaching Practices and Student Learning at 4-Year Institutions.

The faculty workshop model has long been used for disseminating innovative methods in STEM education. Despite significant investments by researchers and funding agencies, there is a dearth of evidence regarding downstream impacts of faculty development. CREATE is an evidence-based strategy for teaching science using primary literature. In this study, we examined whether workshop-trained faculty applied CREATE methods effectively and whether their students achieved either cognitive or affective gains. We followed 10 workshop alumni at different 4-year institutions throughout the United States. External observations of the teaching indicated a high fidelity of CREATE implementation. The students made significant gains in cognitive (e.g., designing experiments) and affective (e.g., self-efficacy in science process skills) domains. Some student outcomes correlated with particular characteristics (e.g., class size) but not with others (e.g., teaching experience). These findings provide evidence for the robustness of the CREATE dissemination model and provide perspective on factors that may influence pedagogical reform efforts.

Mini-review: CREATE-ive use of primary literature in the science classroom.

CREATE (Consider, Read, Elucidate hypotheses, Analyze and interpret data, Think of the next Experiment) is a pedagogical approach for teaching and learning science through the rigorous analysis of primary scientific literature. This mini-review focuses on the tools, assignments, and in-class activities by which this strategy immerses students in the process of science and further challenges students to embody the intellectual activities of actual scientists. We highlight the innovative ways in which CREATE pedagogy encourages students to think deeply about science. Applying this strategy has been shown to promote student gains in cognitive and affective behaviors while also fostering the development of science process skills. Herein we also provide a case study of CREATE implementation, which provides a detailed perspective on the realities of teaching with this strategy. Finally, we offer insights gained through the study of this pedagogy at different types of institutions, courses and student populations to demonstrate how CREATE can be broadly applied in STEM education.

Coordinating proliferation and tissue specification to promote regional identity in the Drosophila head.

The Decapentaplegic and Notch signaling pathways are thought to direct regional specification in the Drosophila eye-antennal epithelium by controlling the expression of selector genes for the eye (Eyeless/Pax6, Eyes absent) and/or antenna (Distal-less). Here, we investigate the function of these signaling pathways in this process. We find that organ primordia formation is indeed controlled at the level of Decapentaplegic expression but critical steps in regional specification occur earlier than previously proposed. Contrary to previous findings, Notch does not specify eye field identity by promoting Eyeless expression but it influences eye primordium formation through its control of proliferation. Our analysis of Notch function reveals an important connection between proliferation, field size, and regional specification. We propose that field size modulates the interaction between the Decapentaplegic and Wingless pathways, thereby linking proliferation and patterning in eye primordium development.

CREATE Two-Year/Four-Year Faculty Workshops: A Focus on Practice, Reflection, and Novel Curricular Design Leads to Diverse Gains for Faculty at Two-Year and Four-Year Institutions.

Improving STEM education through the propagation of highly effective teaching strategies is a major goal of national reform movements. CREATE (Consider, Read, Elucidate the hypotheses, Analyze and interpret the data, and Think of the next Experiment) is a transformative teaching and learning strategy grounded in evidence-based science pedagogy. CREATE courses promote both cognitive (e.g., critical thinking) and affective (e.g., attitudinal and epistemological) student gains in diverse settings. In this study, we look more deeply into the faculty development workshop used to disseminate CREATE pedagogy to instructors at two-year and four-year institutions. We hypothesized that an immersive experience would positively shift faculty participants' views on teaching/learning, build their understanding of CREATE pedagogy and develop their confidence for course implementation. Internal and external assessments indicate that faculty participants did achieve gains within the timeframe of the CREATE workshop. We discuss the workshop training outcomes in the context of designing effective dissemination models for innovative practices.

Testing CREATE at Community Colleges: An Examination of Faculty Perspectives and Diverse Student Gains.

CREATE (Consider, Read, Elucidate the hypotheses, Analyze and interpret the data, and Think of the next Experiment) is an innovative pedagogy for teaching science through the intensive analysis of scientific literature. Initiated at the City College of New York, a minority-serving institution, and regionally expanded in the New York/New Jersey/Pennsylvania area, this methodology has had multiple positive impacts on faculty and students in science, technology, engineering, and mathematics courses. To determine whether the CREATE strategy is effective at the community college (2-yr) level, we prepared 2-yr faculty to use CREATE methodologies and investigated CREATE implementation at community colleges in seven regions of the United States. We used outside evaluation combined with pre/postcourse assessments of students to test related hypotheses: 1) workshop-trained 2-yr faculty teach effectively with the CREATE strategy in their first attempt, and 2) 2-yr students in CREATE courses make cognitive and affective gains during their CREATE quarter or semester. Community college students demonstrated positive shifts in experimental design and critical-thinking ability concurrent with gains in attitudes/self-rated learning and maturation of epistemological beliefs about science.

Using Xenopus to discover new genes involved in branchiootorenal spectrum disorders.

Congenital hearing loss is an important clinical problem because, without early intervention, affected children do not properly acquire language and consequently have difficulties developing social skills. Although most newborns in the US are screened for hearing deficits, even earlier diagnosis can be made with prenatal genetic screening. Genetic screening that identifies the relevant mutated gene can also warn about potential congenital defects in organs not related to hearing. We will discuss efforts to identify new candidate genes that underlie the Branchiootorenal spectrum disorders in which affected children have hearing deficits and are also at risk for kidney defects. Mutations in two genes, SIX1 and EYA1, have been identified in about half of the patients tested. To uncover new candidate genes, we have used the aquatic animal model, Xenopus laevis, to identify genes that are part of the developmental genetic pathway of Six1 during otic and kidney development. We have already identified a large number of potential Six1 transcriptional targets and candidate co-factor proteins that are expressed at the right time and in the correct tissues to interact with Six1 during development. We discuss the advantages of using this system for gene discovery in a human congenital hearing loss syndrome.

Fly SIX-type homeodomain proteins Sine oculis and Optix partner with different cofactors during eye development.

Two members from the Six class of homeobox transcription factors, Sine oculis (SO) and Optix, function during development of the fly visual system. Differences in gain-of-function phenotypes and gene expression suggest that these related factors play distinct roles in the formation of the fly eye. However, the molecular nature of their functional differences remains unclear. In this study, we report the identification of two novel factors that participate in specific partnerships with Sine oculis and Optix during photoreceptor neurons formation and in eye progenitor cells. This work shows that different cofactors likely mediate unique functions of Sine oculis and Optix during the development of the fly eye and that the repeated requirement for SO function at multiple stages of eye development reflects the activity of different SO-cofactor complexes.

Partner specificity is essential for proper function of the SIX-type homeodomain proteins Sine oculis and Optix during fly eye development.

The development of the Drosophila visual system utilizes two members of the highly conserved Six-Homeobox family of transcription factor, Sine oculis and Optix. Although in vitro studies have detected differences in DNA-binding and interactions with some co-factors, questions remain as to what extent the activity for these two transcriptional regulators is redundant or specific in vivo. In this work, we show that the SoD mutation within the Six domain does not abolish DNA-protein interactions, but alters co-factor binding specificity to resemble that of Optix. A mutation in the same region of Optix alters its activity in vivo. We propose that the dominant mutant phenotype is primarily due to an alteration in binding properties of the Sine oculis protein and that distinct partner interactions is one important mechanism in determining significant functional differences between these highly conserved factors during eye development.

Six1 promotes a placodal fate within the lateral neurogenic ectoderm by functioning as both a transcriptional activator and repressor.

Cranial placodes, which give rise to sensory organs in the vertebrate head, are important embryonic structures whose development has not been well studied because of their transient nature and paucity of molecular markers. We have used markers of pre-placodal ectoderm (PPE) (six1, eya1) to determine that gradients of both neural inducers and anteroposterior signals are necessary to induce and appropriately position the PPE. Overexpression of six1 expands the PPE at the expense of neural crest and epidermis, whereas knock-down of Six1 results in reduction of the PPE domain and expansion of the neural plate, neural crest and epidermis. Using expression of activator and repressor constructs of six1 or co-expression of wild-type six1 with activating or repressing co-factors (eya1 and groucho, respectively), we demonstrate that Six1 inhibits neural crest and epidermal genes via transcriptional repression and enhances PPE genes via transcriptional activation. Ectopic expression of neural plate, neural crest and epidermal genes in the PPE demonstrates that these factors mutually influence each other to establish the appropriate boundaries between these ectodermal domains.