Ac/Ds transposition for CRISPR/dCas9-SID4x epigenome modulation in zebrafish.

Due to its genetic amenability coupled with advances in genome editing, zebrafish is an excellent model to examine the function of (epi)genomic elements. Here, we repurposed the Ac/Ds maize transposition system to efficiently characterise zebrafish cis-regulated elements, also known as enhancers, in F0-microinjected embryos. We further used the system to stably express guide RNAs enabling CRISPR/dCas9-interference (CRISPRi) perturbation of enhancers without disrupting the underlying genetic sequence.

Tissue-Specific Biotin Chromatin Immunoprecipitation with Sequencing in Zebrafish and Chicken.

Chromatin immunoprecipitation with sequencing (ChIP-seq) has been instrumental in understanding transcription factor (TF) binding during gene regulation. ChIP-seq requires specific antibodies against desired TFs, which are not available for numerous species. Here, we describe a tissue-specific biotin ChIP-seq protocol for zebrafish and chicken embryos which utilizes AVI tagging of TFs, permitting their biotinylation by a co-expressed nuclear biotin ligase.

Reconstruction of the Global Neural Crest Gene Regulatory Network In Vivo.

Precise control of developmental processes is encoded in the genome in the form of gene regulatory networks (GRNs). Such multi-factorial systems are difficult to decode in vertebrates owing to their complex gene hierarchies and dynamic molecular interactions. Here we present a genome-wide in vivo reconstruction of the GRN underlying development of the multipotent neural crest (NC) embryonic cell population.

GTP-Cyclohydrolase I deficiency presenting as malignant hyperphenylalaninemia, recurrent hyperthermia and progressive neurological dysfunction in a South Asian child - a case report.

Background: Tetrahydrobiopterin (BH) deficiencies are disorders affecting phenylalanine homeostasis, and catecholamine and serotonin biosynthesis. GTP-Cyclohydrolase I deficiency (OMIM 600225) is an extremely rare variant of inborn error of BH synthesis which exists in recessive and dominant forms. The recessive form presents with complex neurological and autonomic dysfunction whilst the dominant form presents as Dopa-responsive dystonia.

Assortativity and mixing patterns in international supply chain networks.

As economic globalisation increases, inclination toward domestic protectionism is also increasing in many countries of the world. To improve the productivity and the resilience of national economies, it is important to understand the drivers and the barriers of the internatiolisation of economic activities. While internatiolisation of individual economic actors is difficult to explain using traditional theories, aggregate patterns may be explained to some extent.