159 research outputs found

    In Utero Diagnosis of Niemann-Pick Type C in the Absence of Family History

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    Niemann-Pick type C (NPC) disease is a recessive disorder that results in unesterified cholesterol accumulating in the lysosomal and late endosomal system. It is caused by mutations in NPC1 or NPC2 genes and leads to systemic and neurodegenerative symptoms. Few cases of prenatal presentation of NPC have been reported and only two cases in the absence of previous family history, indicating the diagnosis is particularly difficult in such a situation. We report a prenatal diagnosis of NPC in a couple without family history. An ultrasound screening at 22 weeks of gestation (WG) detected fetal ascites and hepatomegaly, which were still present at 25, 27, and 29 WG, and a splenomegaly progressively appeared. No placentomegaly or other signs of hydrops fetalis were observed. The diagnostic of NPC was prenatally confirmed by a filipin test and NPC1 sequencing and multiplex ligation-dependent probe amplification assay which revealed a maternal missense mutation (c.2608T>C; p.Ser870Pro) and a paternal deletion of exons 5 to 25. This additional prenatal case of NPC suggests that even in the absence of family history, fetal ascites associated with splenomegaly but no hydrops should nonetheless arouse suspicion concerning this disease as a possible diagnosis

    Identification of a novel Drosophila gene, beltless, using injectable embryonic and adult RNA interference (RNAi)

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    BACKGROUND: RNA interference (RNAi) is a process triggered by a double-stranded RNA that leads to targeted down-regulation/silencing of gene expression and can be used for functional genomics; i.e. loss-of-function studies. Here we report on the use of RNAi in the identification of a developmentally important novel Drosophila (fruit fly) gene (corresponding to a putative gene CG5652/GM06434), that we named beltless based on an embryonic loss-of-function phenotype. RESULTS: Beltless mRNA is expressed in all developmental stages except in 0–6 h embryos. In situ RT-PCR localized beltless mRNA in the ventral cord and brain of late stage embryos and in the nervous system, ovaries, and the accessory glands of adult flies. RNAi was induced by injection of short (22 bp) beltless double-stranded RNAs into embryos or into adult flies. Embryonic RNAi altered cuticular phenotypes ranging from partially-formed to missing denticle belts (thus beltless) of the abdominal segments A2–A4. Embryonic beltless RNAi was lethal. Adult RNAi resulted in the shrinkage of the ovaries by half and reduced the number of eggs laid. We also examined Df(1)RK4 flies in which deletion removes 16 genes, including beltless. In some embryos, we observed cuticular abnormalities similar to our findings with beltless RNAi. After differentiating Df(1)RK4 embryos into those with visible denticle belts and those missing denticle belts, we assayed the presence of beltless mRNA; no beltless mRNA was detectable in embryos with missing denticle belts. CONCLUSIONS: We have identified a developmentally important novel Drosophila gene, beltless, which has been characterized in loss-of-function studies using RNA interference. The putative beltless protein shares homologies with the C. elegans nose resistant to fluoxetine (NRF) NRF-6 gene, as well as with several uncharacterized C. elegans and Drosophila melanogaster genes, some with prominent acyltransferase domains. Future studies should elucidate the role and mechanism of action of beltless during Drosophila development and in adults, including in the adult nervous system

    Biodiversity, Species Protection, and Animal Welfare Under International Law

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    The chapter explores the influence of the concept of animal welfare on international biodiversity law. A close examination of the recent evolution of this branch of international law shows that animal welfare has an ambivalent place in biodiversity-related agreements. Indeed, while welfare is only a faint consideration in the development of international regimes dealing with biodiversity as a whole, the concept has become an essential element for agreements dealing with the conservation of specific endangered species. Despite its role in these agreements, the place of animal welfare in international biodiversity law highlights that this corpus of rules is currently insufficient to be an effective tool for the protection of wildlife welfare. The last section of this study suggests that the adoption of international rules aiming at ensuring the protection of wild animals’ welfare could serve the double purpose of strengthening the conservation purpose of biodiversity regimes while also filling the welfare gap of international biodiversity law

    Genetic regulation of pituitary gland development in human and mouse

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    Normal hypothalamopituitary development is closely related to that of the forebrain and is dependent upon a complex genetic cascade of transcription factors and signaling molecules that may be either intrinsic or extrinsic to the developing Rathke’s pouch. These factors dictate organ commitment, cell differentiation, and cell proliferation within the anterior pituitary. Abnormalities in these processes are associated with congenital hypopituitarism, a spectrum of disorders that includes syndromic disorders such as septo-optic dysplasia, combined pituitary hormone deficiencies, and isolated hormone deficiencies, of which the commonest is GH deficiency. The highly variable clinical phenotypes can now in part be explained due to research performed over the last 20 yr, based mainly on naturally occurring and transgenic animal models. Mutations in genes encoding both signaling molecules and transcription factors have been implicated in the etiology of hypopituitarism, with or without other syndromic features, in mice and humans. To date, mutations in known genes account for a small proportion of cases of hypopituitarism in humans. However, these mutations have led to a greater understanding of the genetic interactions that lead to normal pituitary development. This review attempts to describe the complexity of pituitary development in the rodent, with particular emphasis on those factors that, when mutated, are associated with hypopituitarism in humans

    Genetic and Chemical Modifiers of a CUG Toxicity Model in Drosophila

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    Non-coding CUG repeat expansions interfere with the activity of human Muscleblind-like (MBNL) proteins contributing to myotonic dystrophy 1 (DM1). To understand this toxic RNA gain-of-function mechanism we developed a Drosophila model expressing 60 pure and 480 interrupted CUG repeats in the context of a non-translatable RNA. These flies reproduced aspects of the DM1 pathology, most notably nuclear accumulation of CUG transcripts, muscle degeneration, splicing misregulation, and diminished Muscleblind function in vivo. Reduced Muscleblind activity was evident from the sensitivity of CUG-induced phenotypes to a decrease in muscleblind genetic dosage and rescue by MBNL1 expression, and further supported by the co-localization of Muscleblind and CUG repeat RNA in ribonuclear foci. Targeted expression of CUG repeats to the developing eye and brain mushroom bodies was toxic leading to rough eyes and semilethality, respectively. These phenotypes were utilized to identify genetic and chemical modifiers of the CUG-induced toxicity. 15 genetic modifiers of the rough eye phenotype were isolated. These genes identify putative cellular processes unknown to be altered by CUG repeat RNA, and they include mRNA export factor Aly, apoptosis inhibitor Thread, chromatin remodelling factor Nurf-38, and extracellular matrix structural component Viking. Ten chemical compounds suppressed the semilethal phenotype. These compounds significantly improved viability of CUG expressing flies and included non-steroidal anti-inflammatory agents (ketoprofen), muscarinic, cholinergic and histamine receptor inhibitors (orphenadrine), and drugs that can affect sodium and calcium metabolism such as clenbuterol and spironolactone. These findings provide new insights into the DM1 phenotype, and suggest novel candidates for DM1 treatments
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