Faf1 is expressed during neurodevelopment and is involved in Apaf1-dependent caspase-3 activation in proneural cell

Fas-associated factor 1 (Faf1) has been described as a Fas-binding pro-apoptotic protein and as a component of the death-inducing signaling complex (DISC) in Fas-mediated apoptosis. Faf1 is able to potentiate Fas-induced apoptosis in several cell lines, although its specific functions are still not clear. Here we show that Faf1 is highly expressed in several areas of the developing telencephalon. Its expression pattern appears to be dynamic at different embryonic stages and to be progressively confined within limited territories. To decipher the specific role of Faf1 in developing brain, we used cDNA over-expression and mRNA down-regulation experiments to modulate Faf1 expression in telencephalic neural precursor cells, and we showed that in neural cell death Faf1 acts as a Fas-independent apoptotic enhancer. Moreover, we found that Faf1 protein level is down-regulated during apoptosis in a caspase- and Apaf1-dependent manner

Bioaccumulation and Toxicity of Organic Chemicals in Terrestrial Invertebrates

Terrestrial invertebrates are key components in ecosystems, with crucial roles in soil structure, functioning, and ecosystem services. The present chapter covers how terrestrial invertebrates are impacted by organic chemicals, focusing on up-to-date information regarding bioavailability, exposure routes and general concepts on bioaccumulation, toxicity, and existing models. Terrestrial invertebrates are exposed to organic chemicals through different routes, which are dependent on both the organismal traits and nature of exposure, including chemical properties and media characteristics. Bioaccumulation and toxicity data for several groups of organic chemicals are presented and discussed, attempting to cover plant protection products (herbicides, insecticides, fungicides, and molluscicides), veterinary and human pharmaceuticals, polycyclic aromatic compounds, polychlorinated biphenyls, flame retardants, and personal care products. Chemical mixtures are also discussed bearing in mind that chemicals appear simultaneously in the environment. The biomagnification of organic chemicals is considered in light of the consumption of terrestrial invertebrates as novel feed and food sources. This chapter highlights how science has contributed with data from the last 5 years, providing evidence on bioavailability, bioaccumulation, and toxicity derived from exposure to organic chemicals, including insights into the main challenges and shortcomings to extrapolate results to real exposure scenarios

Live transgenic reporters of the vertebrate embryo's Segmentation Clock

Imaging rapidly changing gene expression during embryogenesis is a challenge for the development of probes and imaging techniques. The vertebrate Segmentation Clock is a genetic network that controls the subdivision of the elongating embryonic body axis into somites, the precursors of adult segmented structures, such as vertebrae. Because of its rapid oscillations, direct observation of gene expression in this system has proven difficult, and so is a benchmark for transgene design and imaging in vivo. Transgenic approaches using destabilized reporter cassettes in the mouse embryo have provided the first glimpses of this dynamic expression system. Nevertheless, improvements in temporal and spatial resolution, paired with the ability to make precise quantifications, will be necessary to connect observations and theory

Live transgenic reporters of the vertebrate embryo's Segmentation Clock

Imaging rapidly changing gene expression during embryogenesis is a challenge for the development of probes and imaging techniques. The vertebrate Segmentation Clock is a genetic network that controls the subdivision of the elongating embryonic body axis into somites, the precursors of adult segmented structures, such as vertebrae. Because of its rapid oscillations, direct observation of gene expression in this system has proven difficult, and so is a benchmark for transgene design and imaging in vivo. Transgenic approaches using destabilized reporter cassettes in the mouse embryo have provided the first glimpses of this dynamic expression system. Nevertheless, improvements in temporal and spatial resolution, paired with the ability to make precise quantifications, will be necessary to connect observations and theory. © 2011 Elsevier Ltd

Simple and efficient transgenesis with meganuclease constructs in zebrafish

In the past, microinjection of plasmid DNA into early embryos represented the state of the art to generate transgenic zebrafish. However, this approach suffers significant drawbacks (mosaic distribution of the injected transgene, late transgene integration at high copy numbers, low transgenesis frequency), making the generation of transgenic lines a laborious task. Coinjection of I-SceI meganuclease with a reporter construct flanked by I-SceI sites overcomes these problems by earlier transgene integration into the host genome. Here, we provide an optimized protocol for I-SceI meganuclease-mediated transgenesis in zebrafish. This simple protocol provides a reliable method to transiently test tissue-specific reporter expression of meganuclease constructs in injected embryos (F0). Furthermore, it substantially facilitates the generation of multiple stable transgenic lines increasing transgenesis frequencies up to 45%, compared with 5% without I-SceI. The reliable reporter activity in F0 and the improved transgenesis frequency make this protocol a powerful tool for use in gain- and loss-of-function, cell tracing, and cell labeling experiments

A Novel Transgenic Zebrafish Line for Red Opsin Expression in Outer Segments of Photoreceptor Cells

Opsins are a group of light-sensitive proteins present in photoreceptor cells, which convert the energy of photons into electrochemical signals, thus allowing vision. Given their relevance, we aimed to visualize the two red opsins at subcellular scale in photoreceptor cells