The Opossum genome reveals further evidence for regulatory evolution in mammalian diversification

The first marsupial genome to be sequenced emphasizes the importance of noncoding sequences in mammalian evolution

Sex-biased chromatin and regulatory cross-talk between sex chromosomes, autosomes, and mitochondria

Several autoimmune and neurological diseases exhibit a sex bias, but discerning the causes and mechanisms of these biases has been challenging. Sex differences begin to manifest themselves in early embryonic development, and gonadal differentiation further bifurcates the male and female phenotypes. Even at this early stage, however, there is evidence that males and females respond to environmental stimuli differently, and the divergent phenotypic responses may have consequences later in life. The effect of prenatal nutrient restriction illustrates this point, as adult women exposed to prenatal restrictions exhibited increased risk factors of cardiovascular disease, while men exposed to the same condition did not. Recent research has examined the roles of sex-specific genes, hormones, chromosomes, and the interactions among them in mediating sex-biased phenotypes. Such research has identified testosterone, for example, as a possible protective agent against autoimmune disorders and an XX chromosome complement as a susceptibility factor in murine models of lupus and multiple sclerosis. Sex-biased chromatin is an additional and likely important component. Research suggesting a role for X and Y chromosome heterochromatin in regulating epigenetic states of autosomes has highlighted unorthodox mechanisms of gene regulation. The crosstalk between the Y chromosomes and autosomes may be further mediated by the mitochondria. The organelles have solely maternal transmission and exert differential effects on males and females. Altogether, research supports the notion that the interaction between sex-biased elements might exert novel regulatory functions in the genome and contribute to sex-specific susceptibilities to autoimmune and neurological diseases

How Do Y-Chromosomes Modulate Genome-Wide Epigenetic States: Genome Folding, Chromatin Sinks, and Gene Expression

The Y chromosomes of Drosophila melanogaster and D. simulans contain only a handful of protein-coding genes, which are related to sperm mobility and reproductive fitness. Despite low or absent protein coding polymorphism, the Drosophila Y chromosome has been associated with natural phenotypic variation, including variation in the expression of hundreds to thousands of genes located on autosomes and on the X chromosome. Polymorphisms present in the large blocks of heterochromatin and consisting of differences in the amounts and kinds of sequences for satellite DNA and transposable elements may be the source of this modulation. Here we review the evidence and discuss mechanisms for global epigenetic regulation by repetitious elements in the Y chromosome. We also discuss how the discovery of this new function impacts the current knowledge about Y chromosome origin, its current dynamics, and future fate

Tacit Knowledge Transfer within Organisations

Knowledge and management of such knowledge have been studied for some time now as it became clear that a company with an unstructured approach to corporate knowledge management was incapable of competing in this new environment. As such, management of intangible assets, such as knowledge, came to be perceived as an important tool for competition. Based on that, this article aims to identify the pertinent factors for tacit knowledge transfer within a major government-controlled publicly-listed Brazilian oil company, namely Petrobras, by using a quantitative approach based on exploratory factorial analysis. It is concluded that idiosyncratic factors, the knowledge management strategy adopted by the company, and its organisational structure are relevant elements for the success of tacit knowledge transfer within the organisation. Hence, three propositions arising from the results obtained are consolidated and presented in order that they may be tested in a future explanatory study

Mito-nuclear interactions as drivers of gene movement on and off the X-chromosome

Background: Mito-nuclear gene interactions regulate energy conversion, and are fundamental to eukaryotes. Generally, mito-nuclear coadaptation would be most efficient if the interacting nuclear genes were X-linked, because this maximizes the probability of favorable mito-nuclear allelic combinations co-transmitting across generations. Thus, under a coadaptation (CA) hypothesis, nuclear genes essential for mitochondrial function might be under selection to relocate to the X-chromosome. However, maternal inheritance predisposes the mitochondrial DNA (mtDNA) to accumulate variation that, while male-harming, is benign to females. Numerous nuclear genes were recently reported in Drosophila melanogaster, which exhibit male-specific patterns of differential expression when placed alongside different mtDNA haplotypes, suggesting that nuclear genes are sensitive to an underlying male-specific mitochondrial mutation load. These genes are thus candidates for involvement in mito-nuclear interactions driven by sexual conflict (SC), and selection might have moved them off the X-chromosome to facilitate an optimal evolutionary counter-response, through males, to the presence of male-harming mtDNA mutations. Furthermore, the presence of male-harming mtDNA mutations could exert selection for modifiers on the Y-chromosome, thus placing these mito-sensitive nuclear genes at the center of an evolutionary tug-of-war between mitochondrion and Y-chromosome. We test these hypotheses by examining the chromosomal distributions of three distinct sets of mitochondrial-interacting nuclear genes in D. melanogaster; the first is a list of genes with mitochondrial annotations by Gene Ontologies, the second is a list comprising the core evolutionary-conserved mitochondrial proteome, and the third is a list of genes involved in male-specific responses to maternally-inherited mitochondrial variation and which might be putative targets of Y-chromosomal regulation. Results: Genes with mitochondrial annotations and genes representing the mitochondrial proteome do not exhibit statistically-significant biases in chromosomal representation. However, genes exhibiting sex-specific sensitivity to mtDNA are under-represented on the X-chromosome, over-represented among genes known to be sensitive to Y-chromosomal variation, and among genes previously associated with male fitness, but under-represented among genes associated with direct sexual antagonism. Conclusions: Our results are consistent with the SC hypothesis, suggesting that mitochondrial mutational pressure selects for gene movement off-the-X, hence enabling mito-nuclear coadaptation to proceed along trajectories that result in optimized fitness in both sexes

Narrating resistant citizenships through two pandemics

Covid has intensified inequalities in the UK, particularly for those already living with structural disadvantage, and despite community and popular resistance to those losses. Covid has also disproportionately affected people with HIV, especially those already living with multi-dimensional inequalities. However, many people with HIV have, as they have done before, made strong and often successful efforts to resist and to restore or reconstruct their citizenships, in opposition to dominant, dispossessing discourses during Covid times. A narrative approach offers a means of mapping these citizenly technologies. This article draws on a 2020 study conducted with 16 people living with HIV in the UK. The study explored, through telephone semi-structured interviews, the health, economic, and psychosocial resources with which these participants lived with HIV and how Covid has impacted those resources. Narrative analysis showed losses of HIV and other health resources, constituting reductions in health citizenship, resisted largely by reconstitutions of alternatives within the HIV sector; losses of economic citizenship, despite oppositional, anti-political attempts to retain it, and of psychosocial citizenship, in spite of family and friendship networks; resistant, ‘alter’ development of renewed HIV citizenships; and across fields, resistance by complaint. This study indicates that ‘de-citizening’ citizenship losses are likely to also affect other groups with long-term conditions, illnesses, and disabilities. Resistant ‘re-citizening’ technologies, while important, had limited effects. The study suggests potential future resistant effects of repeated ‘complaint’ about Covid-era citizenship losses, and the more general significance of histories of dissent for future effective resistance

Deficiência, inclusão e exclusão na escola: percepções de professores de escolas públicas municipais de Florianópolis.

TCC (graduação) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Curso de Ciências Sociais.Este trabalho propõe-se a analisar as experiências em sala de aula, de professores que atuam com alunos com deficiência em escolas públicas municipais de Florianópolis, além de analisar percepções, possíveis limites e potencialidades dessa experiência escolar, a partir de seus relatos cotidianos com as políticas de inclusão. Para contextualizar a questão da deficiência na escola, recorremos à pesquisa documental sobre a legislação pertinente ao assunto, bem como a revisão da literatura especializada sobre o tema. Busca-se refletir sobre algumas questões que tratam da exclusão da pessoa com deficiência e das dificuldades de inclusão da mesma no ambiente escolar, bem como um referencial teórico que discute a normatização do ensino e propostas de inclusão podem gerar exclusão, bem como analisar as representações que esses profissionais têm sobre esses alunos, suas estratégias pedagógicas e agenciamentos para lidar com eles, com a diferença entre eles e os demais alunos, e possíveis conflitos. Desse modo, o trabalho pretende oferecer contribuições à discussão da escola enquanto espaço de diversidade.This paper aims to analyze classroom experiences of teachers who work with students with disabilities in municipal public schools in Florianopolis, as well as to analyze perceptions, possible limits and potentialities of this school experience, based on their daily reports with the inclusion policies. To contextualize the issue of disability in school, we used documentary research on relevant legislation, as well as a review of specialized literature on the subject. It is sought to reflect on some issues that deal with the exclusion of the disabled person and the difficulties of inclusion of the same in the school environment, as well as a theoretical reference that discusses the normatization of teaching and proposals of inclusion can generate exclusion, as well as to analyze representations that these professionals have about these students, their pedagogical strategies and assemblies to deal with them, the difference between them and the other students, and possible conflicts. In this way, the work intends to offer contributions to the discussion of the school as a space of diversity

DIVERSIDADE E INCLUSÃO NA ESCOLA: Análise de experiências de um aluno autista em uma escola pública de Florianópolis-SC

TCC(especialização) - Universidade Federal de Santa Catarina. Centro de Filosofia de Ciências Humanas. Gênero e Diversidade na Escola.A escola como espaço de aprendizado, de vivências sociais e multiplicidade tem papel significativo na formação das pessoas, e também na formação social. Desse modo torna-se necessário discutir sobre questões ligadas à diversidade e inclusão no espaço escolar. Perceber o outro além da deficiência, percebê-lo além do que difere, e a partir de aí traçar um caminho para a vivência múltipla de relações sociais de respeito mútuo. O presente trabalho propõe analisar como se dá a inclusão e a diversidade no espaço escolar através da análise de experiências vividas por uma classe de alunos de uma escola que possui um aluno autista. O objetivo do trabalho consiste em refletir sobre a questão da deficiência e gênero, levando em conta a multiplicidade dos aspectos que envolvem tais questões, através de uma abordagem da deficiência como uma forma de diversidade, ou em outras palavras, de multiplicidade do ser humano, e de como essa forma vivencia suas próprias questões. Esta análise foi feita a partir da experiência em uma escola pública do município de Florianópolis, através da observação e registro de campo. A partir das observações, percebeu-se a reprodução de discursos de exclusão, ligados à capacidade cognitiva da pessoa com autismo. Perceberam-se questões ligadas ao ensino, à cognição e à sexualidade da pessoa com deficiência. The school as a space dedicated to learning, social experiences and multiplicity plays a significant role in the formation of individuals, and also in social formation. In this way it becomes necessary to discuss issues related to diversity and inclusion in the school space. To perceive the other besides the deficiency, to perceive it beyond what it differs, and from there to trace a way to the multiple experience of social relations and mutual respect. The present work proposes to analyze how the inclusion and diversity in the school space takes place through the analysis of experiences lived by an autistic student. Reflect on the issue of disability and gender, taking into account the multiplicity of aspects that involve such issues, through an approach to disability as a form of diversity, or in other words, multiplicity of the human being, and analyze how they experience/ their own issues. This analysis was made from the experience in a public school of the municipality of Florianópolis, through observation and field registration. From the observations, the reproduction of discourses of exclusion, linked to the cognitive capacity of the person with autism, was perceived. Issues related to the teaching, cognition and sexuality of the person with disabilities were also perceived

More epigenetic hits than meets the eye: microRNAs and genes associated with the tumorigenesis of retinoblastoma

Retinoblastoma (RB), a childhood neoplasia of the retinoblasts, can occur unilaterally or bilaterally, with one or multiple foci per eye. RB is associated with somatic loss of function of both alleles of the tumor suppressor gene RB1. Hereditary forms emerge due to germline loss of function mutations in RB1 alleles. RB has long been the prototypic “model” cancer ever since Knudson's “two-hit” hypothesis. However, a simple two-hit model for RB is challenged by an increasing number of studies documenting additional hits that contribute to RB development. Here we review the genetics and epigenetics of RB with a focus on the role of small non-coding RNAs (microRNAs) and on novel findings indicating the relevance of DNA methylation in the development and prognosis of this neoplasia. Studies point to an elaborated landscape of genetic and epigenetic complexity, in which a number of events and pahtways play crucial roles in the origin and prognosis of RB. These include roles for microRNAs, inprinted loci, and parent-of-origin contributions to RB1 regulation and RB progression. This complexity is also manifested in the structure of the RB1 locus itself: it includes numerous repetitive DNA segments and retrotransposon insertion elements, some of which are actively transcribed from the RB1 locus. Altogether, we conclude that RB1 loss of function represents the tip of an iceberg of events that determine RB development, progression, severity, and disease risk. Comprehensive assessment of personalized RB risk will require genetic and epigenetic evaluations beyond RB1 protein coding sequences