Effect of dietary antagonists and corresponding nutrients on growth and reproduction of the flour mite (Acarus siro L.)

The flour miteAcarus siro L. (Acaridae, Astigmata) was reared on an axenic diet with the addition of various nutrient antagonists, with and without supplementation by the corresponding nutrients. The deficiency symptoms induced by dietary antagonists, and the reversibility of the former by nutrient administration, indicated that folic acid, riboflavin, thiamine, niacin, pyridoxine, biotin and a sterol are essential for the growth and reproduction of the flour mite. It was also demonstrated that the population density and generation sequence of this species can be suppressed to the level of acaristasis by nutrient antagonists, owing to inhibited nutrient utilization.Durch die Zugabe von Antiwuchsstoffen können wir nachweisen, daß das Wachstum der betreffenden Organismen gehemmt wird, und daß diese Hemmung durch die Zugabe des entsprechenden Wuchsstoffes wieder aufgehoben wird.Nielsen, N., Wuchsstoffe und Antiwuchsstoffe der Mikroorganismen. Verlag Gustav Fischer, Jena 1945.     

Identification and nucleotide sequence of a human locus homologous to the v-myc oncogene of avian myelocytomatosis virus MC29

Avian myelocytomatosis virus MC29 is a replication-defective acute leukaemia virus which induces a variety of tumours in chickens including sarcomas, renal and hepatic carcinomas, and myelocytomatosis. The oncogenic potential of the virus is mediated by the gene v-myc, acquired from sequences (c-myc) present in normal uninfected chicken DNA. Sequences closely related to chicken c-myc have been highly conserved throughout evolution, from Drosophila to vertebrates. The hypothesis that c-myc may be involved in neoplastic transformation has been strengthened by the finding that B-cell lymphomas induced in chickens by avian leukosis virus (ALV) are often associated with increased expression of c-myc resulting from integration of the ALV provirus adjacent to the c-myc gene. More recently, it has been demonstrated that the malignant human cell line HL-60, derived from the peripheral blood leukocytes of a patient with acute promyelocytic leukaemia, expresses elevated levels of myc-related mRNA associated with an amplification of the c-myc gene. To explore the relationship of the human cellular myc gene with the corresponding viral oncogene from MC29, and to provide a framework for the analysis of the mechanism and significance of c-myc amplification in human tumours, we have isolated and determined the nucleotide sequence of a genomic clone prepared from a normal human library which contains all domains sharing homology with v-myc.     

PLA2G6, encoding a phospholipase A2, is mutated in neurodegenerative disorders with high brain iron

Neurodegenerative disorders with high brain iron include Parkinson disease, Alzheimer disease and several childhood genetic disorders categorized as neuroaxonal dystrophies. We mapped a locus for infantile neuroaxonal dystrophy (INAD) and neurodegeneration with brain iron accumulation (NBIA) to chromosome 22q12-q13 and identified mutations in PLA2G6, encoding a calcium-independent group VI phospholipase A2, in NBIA, INAD and the related Karak syndrome. This discovery implicates phospholipases in the pathogenesis of neurodegenerative disorders with iron dyshomeostasis.     

Disrupted fertility of the hidebeetleDermestes maculatus (Deg.) due to dietary overdosage of biotin

Zusammenfassung Verabreichung übermässiger Biotindosen (0,5 und 1,0% in synthetischer Diät) an Speckkäfer (Dermestes maculatus Deg.) erzeugt Sterilisation der Weibchen und nicht der Männchen, ohne die Kopulation und Lebensdauer der Insekten negativ zu beeinflussen. Die embryozide Wirkung des Biotinüberschusses kann durch starke Herabsetzung des Vitaminspiegels in der Diät aufgehoben werden. Bei anderen B-Vitaminen, Desthiobiotin und Pimelinsäure konnte ein derartiger Einfluss nicht festgestellt werden. Andererseits schadet Verfütterung obgenannter Biotinmengen der Larvenentwicklung in keiner Weise.     

Structure and organization of the human Ki-ras proto-oncogene and a related processed pseudogene

Analysis of the organization and nucleotide sequence of two human loci related to the transforming gene of Kirsten murine sarcoma virus establishes one as a functional gene and the other as a processed pseudogene. The two final coding exons of the functional gene seem to have arisen by duplication. Differentially spliced mRNAs incorporating one or other of the duplicated exons probably served as the intermediates by which the viral transforming gene and the pseudogene were generated. This suggests that the functional gene may specify either of two related polypeptides depending on the pattern of RNA splicing.