The 8th International Biocuration Conference 2015

正Beijing,China,April 23..26,2015The 8th International Biocuration Conference will be organized by Chinese Academy of Medical Sciences(CAMS)at Beijing Friendship Hotel,Beijing,China,April 23..26,2015.Biocuration involves the translation and integration of information relevant to biology into a database or resource that enables integration of the scientific literature as well as large     

The 8~(th) International Biocuration Conference 2015Beijing,China,April 23-26,2015

正The 8th International Biocuration Conference will be organized by Chinese Academy of Medical Sciences(CAMS)at Beijing Friendship Hotel:Beijing,China,April 23-26,2015.Blocuration involves the translation and integration of information relevant to biology into a database or resource that enables integration of the scientific literature as well as large     

Insights into Dynamic Mitotic Chromatin Organization Through the NIMA Kinase Suppressor SonC,a Chromatin-Associated Protein Involved in the DNA Damage Response

The nuclear pore complex proteins SonA and SonB, the orthologs of mammalian RAE1 and NUP98, respectively, were identified in Aspergillus nidulans as cold-sensitive suppressors of a temperature-sensitive allele of the essential mitotic NIMA kinase (nimA1). Subsequent analyses found that sonB1 mutants exhibit temperature-dependent DNA damage sensitivity. To understand this pathway further, we performed a genetic screen to isolate additional conditional DNA damage-sensitive suppressors of nimA1. We identified two new alleles of SonA and four intragenic nimA mutations that suppress the temperature sensitivity of the nimA1 mutant. In addition, we identified SonC, a previously unstudied binuclear zinc cluster protein involved with NIMA and the DNA damage response. Like sonA and sonB, sonC is an essential gene. SonC localizes to nuclei and partially disperses during mitosis. When the nucleolar organizer region (NOR) undergoes mitotic condensation and removal from the nucleolus, nuclear SonC and histone H1 localize in a mutually exclusive manner with H1 being removed from the NOR region and SonC being absent from the end of the chromosome beyond the NOR. This region of chromatin is adjacent to a cluster of nuclear pore complexes to which NIMA localizes last during its progression around the nuclear envelope during initiation of mitosis. The results genetically extend the NIMA regulatory system to include a protein with selective large-scale chromatin location observed during mitosis. The data suggest a model in which NIMA and SonC, its new chromatin-associated suppressor, might help to orchestrate global chromatin states during mitosis and the DNA damage response.     

Isthmus organizer for mesencephalon and metencephalon

The vertebrate central nervous system is elaborated from a simple neural tube. Brain vesicles formation is the first sign of regionalization. Classical transplantation using quail and chick embryos revealed that the mesencephalon–metencephalon boundary (isthmus) functions as an organizer of the mesencephalon and metencephalon. Fgf8 is accepted as a main organizing molecule of the isthmus. Strong Fgf8 signal activates the Ras-ERK signaling pathway to differentiate the cerebellum. In this review, the historical background of the means of identifying the isthmus organizer and the molecular mechanisms of signal transduction for tectum and cerebellum differentiation is reviewed.     

Number and distribution of silver-stained nucleolar organizer regions and evolutionary relationships in domestic pigs

Variation in the numbers of silver-stained nucleolar organizer regions (Ag-NORS) were examined in 36 breeds of domestic pig of different geographic origins and five subspecies of wild boar. The relationship between Ag-NORs and evolution of domestic pigs was investigated. In all pigs observed, Ag-NORs were localized on the secondary constriction of chromosomes 10 and 8. The mean Ag-NOR numbers varied from 2.0–4.0, and decreased gradually with the different geographical distribution from south to north in China and from east to west in Europe. This regular change was caused mainly by the differences of frequency in chromosome 8 Ag-NOR type and was closely related to the evolution of domestic pig breeds.     

The spatial organization of nucleolar DNA in phytohemagglutinin-stimulated lymphocytes of the guinea pig

Summary The ultrastructural changes in the spatial organization of nucleolar DNA in lymphocytes during phytohemagglutinin (PHA) stimulation was studied in guinea pigs by means of oxidized diaminobenzidine (DAB) at low pH as a differentially contrasting stain for nucleic acids and by the use of reconstruction of serial sections.The extended DNA filaments situated inside the fibrillar area originate from a large aggregation of heterochromatin, which is closely associated with the nucleolus, and from the perinucleolar shell of condensed chromatin. It is suggested that these two distinct regions of chromatin might be associated with different functions.