No abstract

Lead intoxication affects the central nervous system and produces structural disorders and behavioral deficits in several animal species. Although lead neurotoxicity is a well-reported phenomenon, studies on the developmental neurotoxicity induced by this metal in avian are scarce. The aim of this study was to evaluate how a single dose of 28 mug lead acetate administered into the yolk sac on the fifth incubation day of Gallus domesticus can affect the behavior and the brain tissue in the first postnatal week. Several behavioral tests, mainly those related to the motor and exploratory functions were evaluated at fifth and sixth postnatal days (PN). The lead deposition into mesencephalon and cerebellum was investigated by autometallography (AMG) method. Congenital anomalies, as failure on closure of body's ventral midline and leg dysfunction, were observed in treated chicks. During the first postnatal week, inactivity and anomalous movements were significantly high in lead treated chicks in comparison to control animals. Lead impregnation was observed in both mesencephalon and cerebellum and the cerebellar molecular layer presented higher lead deposition in comparison to granular layer and Purkinje cells. Our results indicate that the in ovo exposure to lead induces important deficits on motor behavior of chicks during the first postnatal week and such phenomena are related to lead deposition in the cerebellar tissue during embryonic development. The proposed exposure schedule represents an interesting experimental approach for studding behavioral and cellular mechanisms related to lead-induced developmental neurotoxicity.

Maternal ingestion of folic acid (FA) reduces neural tube defects, which are associated with high homocysteine levels. Present study evaluated the effects of FA and homocysteine on cell proliferation and cell adhesion, as well as on apoptosis, throughout the development of the spinal cord and mesenchyme of chicken embryos. Normal closure of the neural tube and a regular distribution of the mesenchymal cells were observed in control and FA-treated embryos. All homocysteine-treated embryos and also 6 of 10 embryos treated with FA+homocysteine showed failure of closure of the neural tube. Homocysteine decreased the thickness of the mantle and marginal layers of the spinal cord, and FA did not prevent this effect. FA treatment reversed the decrease of proliferating cells in the spinal cord induced by homocysteine. FA-treated embryos showed the highest numerical density of apoptotic cells. Homocysteine treatment reduced NCAM expression in both spinal cord and mesenchymal tissue, and FA prevents this effect. These results are important because they demonstrate in situ that the imbalance between FA and homocysteine levels can lead to disruptions in spinal cord development, changing proliferation, apoptosis, and cell adhesion and consequently changing the arrangement of the spinal cord layers.

The Sultanate of Oman is a rapidly developing Muslim country with well-organized government-funded health care services, and expanding medical genetic facilities. The preservation of tribal structures within the Omani population coupled with geographical isolation has produced unique patterns of rare mutations. In order to provide diagnosticians and researchers with access to an up-to-date resource that will assist them in their daily practice we collated and analyzed all of the Mendelian disease-associated mutations identified in the Omani population. By the 1 st of August 2015, the dataset contained 300 mutations detected in over 150 different genes. More than half of the data collected reflect novel genetic variations that were first described in the Omani population, and most disorders with known mutations are inherited in an autosomal recessive fashion. A number of novel Mendelian disease genes have been discovered in Omani nationals, and the corresponding mutations are included here. The current study provides a comprehensive resource of the mutations in the Omani population published in scientific literature or reported through service provision that will be useful for genetic care in Oman and will be a starting point for variation databases as next-generation sequencing technologies are introduced into genetic medicine in Oman.

No abstract

Our data clarified the relationship between spinal NTD genesis and disruptions of Pax 1/9 and Sox 9 gene products in the axial mesenchyme caused by the FA/Hcy imbalance.