The ZIC gene family encodes multi-functional proteins essential for patterning and morphogenesis

The zinc finger of the cerebellum gene (ZIC) discovered in Drosophila melanogaster (odd-paired) has five homologs in Xenopus, chicken, mice, and humans, and seven in zebrafish. This pattern of gene copy expansion is accompanied by a divergence in gene and protein structure, suggesting that Zic family members share some, but not all, functions. ZIC genes are implicated in neuroectodermal development and neural crest cell induction. All share conserved regions encoding zinc finger domains, however their heterogeneity and specification remain unexplained. In this review, the evolution, structure, and expression patterns of the ZIC homologs are described; specific functions attributable to individual family members are supported. A review of data from functional studies in Xenopus and murine models suggest that ZIC genes encode multifunctional proteins operating in a context-specific manner to drive critical events during embryogenesis. The identification of ZIC mutations in congenital syndromes highlights the relevance of these genes in human development.     

Reinterpretation of the ultrastructure of cartilage matrix.

The epiphyseal cartilage from new-born mouse was treated with collagenase in two ways: either before fixation or after glutaraldehyde fixation. The electron dense granules of the matrix were not seen in the micrographs of cartilage treated with collagenase before fixation. It is concluded that collagen plays a definite role in the formation of the granules at the time of tissue fixation and that the granules are fixation artifacts.     

Physiogenomic resources for rat models of heart, lung and blood disorders

Cardiovascular disorders are influenced by genetic and environmental factors. The TIGR rodent expression web-based resource (TREX) contains over 2,200 microarray hybridizations, involving over 800 animals from 18 different rat strains. These strains comprise genetically diverse parental animals and a panel of chromosomal substitution strains derived by introgressing individual chromosomes from normotensive Brown Norway (BN/NHsdMcwi) rats into the background of Dahl salt sensitive (SS/JrHsdMcwi) rats. The profiles document gene-expression changes in both genders, four tissues (heart, lung, liver, kidney) and two environmental conditions (normoxia, hypoxia). This translates into almost 400 high-quality direct comparisons (not including replicates) and over 100,000 pairwise comparisons. As each individual chromosomal substitution strain represents on average less than a 5% change from the parental genome, consomic strains provide a useful mechanism to dissect complex traits and identify causative genes. We performed a variety of data-mining manipulations on the profiles and used complementary physiological data from the PhysGen resource to demonstrate how TREX can be used by the cardiovascular community for hypothesis generation.     

Action du succinate de soude sur la respiration

Summary Intravenous injection of sodium succinate in dogs anesthetized with chloralosane produces a prolonged stimulation of respiration and decreases the duration of the apnea following pulmonary hyperventilation.     

Genome-wide association scan in women with systemic lupus erythematosus identifies susceptibility variants in ITGAM, PXK, KIAA1542 and other loci

Systemic lupus erythematosus (SLE) is a common systemic autoimmune disease with complex etiology but strong clustering in families (lambda(S) = approximately 30). We performed a genome-wide association scan using 317,501 SNPs in 720 women of European ancestry with SLE and in 2,337 controls, and we genotyped consistently associated SNPs in two additional independent sample sets totaling 1,846 affected women and 1,825 controls. Aside from the expected strong association between SLE and the HLA region on chromosome 6p21 and the previously confirmed non-HLA locus IRF5 on chromosome 7q32, we found evidence of association with replication (1.1 x 10(-7) < P(overall) < 1.6 x 10(-23); odds ratio = 0.82-1.62) in four regions: 16p11.2 (ITGAM), 11p15.5 (KIAA1542), 3p14.3 (PXK) and 1q25.1 (rs10798269). We also found evidence for association (P < 1 x 10(-5)) at FCGR2A, PTPN22 and STAT4, regions previously associated with SLE and other autoimmune diseases, as well as at > or =9 other loci (P < 2 x 10(-7)). Our results show that numerous genes, some with known immune-related functions, predispose to SLE.     

Observations expérimentales sur l'apnée acapnique chez le Chien

Summary Suppression of the chemo-receptors of the carotid sinus and aorta æreas prolongs the acapnic apnea markedly. Animals deprived of their chemo-receptors may even die in apnea.During hyperventilation, the expiratory position of the thorax increases. During the acapnic apnea the inspiratory position returns progressively to normal. During hyperventilation and acapnic apnea, rhythmic changes occur in the tonus of the respiratory muscles. These changes in tonus occur in normal animals as well as in animals deprived of their chemo-receptors and vagi nerves.In normal dogs, hyperventilation and acapnea do not induce a fall in arterial blood pressure. Arterial hypotension occurs, however, during hyperventilation in dogs deprived of their carotid sinus and aortic innervation. During acapnic apnea, the arterial blood pressure rises in animals deprived of their carotid sinus and aortic nerves. A secondary fall of arterial pressure occurs during prolonged acapnic apnea in these animals.