Scaffold attachment factor B: distribution and interaction with ERα in the rat brain

First neurotranscriptome of adults Tambaquis (Colossoma macropomum) with characterization and differential expression between males and females

The Tambaqui is one of the most representative Amazon fish species, being highly exploited in fisheries, aquaculture and as a research model. Nonetheless, data about functional genome are still required to evaluate reproductive and nutrition parameters as well as resistance to pathogens. The of next-generation sequencing has allows assessing the transcriptional processes in non-model species by providing comprehensive gene collections to be used as a database in further genomic applications and increased performance of captive populations. In this study, we relied on RNAseq approach to generate the first transcriptome of the telencephalon from adult males and females of Colossoma macropomum, resulting in a reference dataset for future functional studies. We retrieved 896,238 transcripts, including the identification of 267,785 contigs and 203,790 genes. From this total, 91 transcripts were differentially expressed, being 63 and 28 of them positively regulated for females and males, respectively. The functional annotation resulted in a library of 40 candidate genes for females and 20 for males. The functional enrichment classes comprised reproductive processes (GO:0,048,609; GO:0,003,006; GO:0,044,703; GO:0,032,504; GO:0,019,953) being related to sex differentiation (e.g., SAFB) and immune response (e.g., SLC2A6, AHNAK, NLRC3, NLRP3 and IgC MHC I alpha3), thus indicating that the genes in the neurotranscriptome of Tambaqui participate in sex differentiation and homeostasis of captive specimens. These data are useful to design the selection of genes related to sex determination and animal welfare in raising systems of Tambaqui.

Subcellular dynamics of estrogen-related receptors involved in transrepression through interactions with scaffold attachment factor B1

Estrogen-related receptor (ERR), a member of the nuclear receptor superfamily, consists of three subtypes (α, β, γ) and has strong homology with estrogen receptor. No endogenous ligands have been identified for ERRs, but they play key roles in metabolic, hormonal, and developmental processes as transcription factors without ligand binding. Although subnuclear dynamics are essential for nuclear events including nuclear receptor-mediated transcriptional regulation, the dynamics of ERRs are poorly understood. Here, we report that ERRs show subcellular kinetic changes in response to diethylstilbestrol (DES), a synthetic estrogen that represses the transactivity of all three ERR subtypes, using live-cell imaging with fluorescent protein labeling. Upon DES treatment, all ERR subtypes formed discrete clusters in the nucleus, with ERRγ also displaying nuclear export. Fluorescence recovery after photobleaching analyses revealed significant reductions in the intranuclear mobility of DES-bound ERRα and ERRβ, and a slight reduction in the intranuclear mobility of DES-bound ERRγ. After DES treatment, colocalization of all ERR subtypes with scaffold attachment factor B1 (SAFB1), a nuclear matrix-associated protein, was observed in dot-like subnuclear clusters, suggesting interactions of the ERRs with the nuclear matrix. Consistently, co-immunoprecipitation analyses confirmed enhanced interactions between ERRs and SAFB1 in the presence of DES. SAFB1 was clarified to repress the transactivity of all ERR subtypes through the ERR-response element. These results demonstrate ligand-dependent cluster formation of ERRs in the nucleus that is closely associated with SAFB1-mediated transrepression. Taken together, the present findings provide a new understanding of the pathophysiology regulated by ERR/SAFB1 signaling pathways and their subcellular dynamics.

Epitranscriptomic m6A regulation following spinal cord injury

RNA methylation is involved in multiple physiological and pathological processes. However, the role of RNA methylation in spinal cord regeneration has not been reported. In this study, we find an altered m6A (N6-methyladenosine) RNA methylation profiling following zebrafish spinal cord injury (SCI), in line with an altered transcription level of the m6A methylase Mettl3. Interestingly, many of the differential m6A-tagged genes associated with neural regeneration are hypomethylated, but their transcription levels are upregulated in SCI. Moreover, we find that METTL3 may be important for spinal cord regeneration. We also show a conserved feature of METTL3 changes in mouse SCI model, in which the expression of METTL3 is increased in both astrocytes and neural stem cells. Together, our results indicate that m6A RNA methylation is dynamic and conserved following SCI and may contribute to spinal cord regeneration.