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BACKGROUND: Constitutive activation of the ERK pathway, occurring in the vast majority of melanocytic neoplasms, has a pivotal role in melanoma development. Different mechanisms underlie this activation in different tumour settings. The Grey phenotype in horses, caused by a 4.6 kb duplication in intron 6 of Syntaxin 17 (STX17), is associated with a very high incidence of cutaneous melanoma, but the molecular mechanism behind the melanomagenesis remains unknown. Here, we investigated the involvement of the ERK pathway in melanoma development in Grey horses. METHODS: Grey horse melanoma tumours, cell lines and normal skin melanocytes were analyzed with help of indirect immunofluorescence and immunoblotting for the expression of phospho-ERK1/2 in comparison to that in non-grey horse and human counterparts. The mutational status of BRAF, RAS, GNAQ, GNA11 and KIT genes in Grey horse melanomas was determined by direct sequencing. The effect of RAS, RAF and PI3K/AKT pathways on the activation of the ERK signaling in Grey horse melanoma cells was investigated with help of specific inhibitors and immunoblotting. Individual roles of RAF and RAS kinases on the ERK activation were examined using si-RNA based approach and immunoblotting. RESULTS: We found that the ERK pathway is constitutively activated in Grey horse melanoma tumours and cell lines in the absence of somatic activating mutations in BRAF, RAS, GNAQ, GNA11 and KIT genes or alterations in the expression of the main components of the pathway. The pathway is mitogenic and is mediated by BRAF, CRAF and KRAS kinases. Importantly, we found high activation of the ERK pathway also in epidermal melanocytes, suggesting a general predisposition to melanomagenesis in these horses. CONCLUSIONS: These findings demonstrate that the presence of the intronic 4.6 kb duplication in STX17 is strongly associated with constitutive activation of the ERK pathway in melanocytic cells in Grey horses in the absence of somatic mutations commo, De två första författarna delar förstaförfattarskapet.

The role of green space was considered in the paper. The basic negative impacts on the quantity and quality of green spaces were defined. It was set that the optimization of green areas exploitation is main prerequisite of the urban environment improvement which requires their comprehensive study, assessment of natural resource potential and its possible changes, study of the approaches to their use without damage to nature and people to be. The implementation of proposed recommendations within geoecological approach allows to detect complex structural and functional properties of green spaces geosystem as natural objects and finding ways for their improvement., Проанализирована основная причина химического загрязнения окружающей среды в результате деятельности топливозаправочных объектов, а именно потеря углеводородного сырья, которая происходит при товарно-транспортных операциях и эксплуатации несовершенного оборудования. Отмечено, что источниками негативных влияний топливозаправочных объектов являются дождевые воды, которые смывают с территории разлитые нефтепродукты, а прямое загрязнение окружающей среды в результате аварийных разливов нефтепродуктов редкое явление. Указано, что негативные последствия деятельности АЗС распространяются на атмосферный воздух, прилегающую почву и водные объекты, в том числе грунтовые и подземные воды, загрязняют окружающую среду нефтепродуктами и создают угрозу здоровью людей., Проаналізовано основні причини хімічного забруднення навколишнього середовища внаслідок діяльності паливозаправних об’єктів, а саме втрати вуглеводневої сировини, які відбуваються при товарно-транспортних операціях і експлуатації недосконалого обладнання. Відзначено, що джерелами негативних впливів паливозаправних об’єктів є дощові води, які змивають із території розлиті нафтопродукти, а пряме забруднення навколишнього середовища внаслідок аварійних розливів нафтопродуктів є рідкісним явищем. Указано, що негативні наслідки діяльності АЗС поширюються на атмосферне повітря, прилеглі ґрунти та водні об’єкти, у тому числі ґрунтові та підземні води, забруднюють довкілля та створюють загрозу здоров’ю людей.

Background: Greying with age in horses is an autosomal dominant trait, associated with loss of hair pigmentation, melanoma and vitiligo-like depigmentation. We recently identified a 4.6 kb duplication in STX17 to be associated with the phenotype. The aims of this study were to investigate if the duplication in Grey horses shows copy number variation and to exclude that any other polymorphism is uniquely associated with the Grey mutation. Results: We found little evidence for copy number expansion of the duplicated sequence in blood DNA from Grey horses. In contrast, clear evidence for copy number expansions was indicated in five out of eight tested melanoma tissues or melanoma cell lines. A tendency of a higher copy number in aggressive tumours was also found. Massively parallel resequencing of the similar to 350 kb Grey haplotype did not reveal any additional mutations perfectly associated with the phenotype, confirming the duplication as the true causative mutation. We identified three SNP alleles that were present in a subset of Grey haplotypes within the 350 kb region that shows complete linkage disequilibrium with the causative mutation. Thus, these three nucleotide substitutions must have occurred subsequent to the duplication, consistent with our interpretation that the Grey mutation arose more than 2,000 years before present. Conclusions: These results suggest that the mutation acts as a melanoma-driving regulatory element. The elucidation of the mechanistic features of the duplication will be of considerable interest for the characterization of these horse melanomas as well as for the field of human melanoma research.

Interplay between ultraviolet radiation and skin pigmentation appears to be one of the major risk factors for melanoma development. Allelic variants in a number of pigmentation genes have been associated with increased melanoma susceptibility. PMEL is a melanosomal membrane protein primarily involved in eumelanin synthesis. PMEL functional mutations resulting in hypopigmentation have been identified in a number of vertebrate species, including Dominant white in chickens, Silver in horses, and Merle in dogs. A complete loss of PMEL in transgenic mice had a dramatic effect on the morphology of the melanosomes in skin, hair, and eye, and led to a substantial reduction in the content of eumelanin. No human PMEL mutation associated with any phenotypic effects or disorders has yet been reported. In this study we have investigated the possibility that PMEL mutations may be associated with an increased susceptibility to melanoma in a Nordic polulation by sequencing all 11 exons of PMEL in a cohort of 60 Swedish melanoma patients with a history of familial melanoma. No mutations, apart from the two synonymous SNPs common in general European populations, were found, demonstrating that PMEL mutations do not appear to be a common cause for melanoma susceptibility.

P>In orthodox seeds, the transcriptional activator ABI3 regulates two major stages in embryo maturation: a mid-maturation (MAT) stage leading to accumulation of storage compounds, and a late maturation (LEA) stage leading to quiescence and desiccation tolerance. Our aim was to elucidate mechanisms for transcriptional shutdown of MAT genes during late maturation, to better understand phase transition between MAT and LEA stages. Using transgenic and transient approaches in Nicotiana, we examined activities of two ABI3-dependent reporter genes driven by multimeric RY and abscisic acid response elements (ABREs) from a Brassica napus napin gene, termed RY and ABRE, where the RY reporter requires ABI3 DNA binding. Expression of RY peaks during mid-maturation and drops during late maturation, mimicking the MAT gene program, and in Arabidopsis thaliana RY elements are over-represented in MAT, but not in LEA, genes. The ABI3 transactivation of RY is inhibited by staurosporine, by a PP2C phosphatase, and by a repressor of maturation genes, VAL1/HSI2. The RY element mediates repression of MAT genes, and we propose that transcriptional shutdown of the MAT program during late maturation involves inhibition of ABI3 DNA binding by dephosphorylation. Later, during seedling growth, VAL1/HSI2 family repressors silence MAT genes by binding RY elements.

In horses, graying with age is an autosomal dominant trait associated with a high incidence of melanoma and vitiligo-like depigmentation. Here we show that the Gray phenotype is caused by a 4.6-kb duplication in intron 6 of STX17 (syntaxin-17) that constitutes a cis-acting regulatory mutation. Both STX17 and the neighboring NR4A3 gene are overexpressed in melanomas from Gray horses. Gray horses carrying a loss-of-function mutation in ASIP (agouti signaling protein) had a higher incidence of melanoma, implying that increased melanocortin-1 receptor signaling promotes melanoma development in Gray horses. The Gray horse provides a notable example of how humans have cherry-picked mutations with favorable phenotypic effects in domestic animals.