Mutations in SLC33A1 cause a lethal autosomal-recessive disorder with congenital cataracts, hearing loss, and low serum copper and ceruloplasmin

Low copper and ceruloplasmin in serum are the diagnostic hallmarks for Menkes disease, Wilson disease, and aceruloplasminemia. We report on five patients from four unrelated families with these biochemical findings who presented with a lethal autosomal-recessive syndrome of congenital cataracts, hearing loss, and severe developmental delay. Cerebral MRI showed pronounced cerebellar hypoplasia and hypomyelination. Homozygosity mapping was performed and displayed a region of commonality among three families at chromosome 3q25. Deep sequencing and conventional sequencing disclosed homozygous or compound heterozygous mutations for all affected subjects in SLC33A1 encoding a highly conserved acetylCoA transporter (AT-1) required for acetylation of multiple gangliosides and glycoproteins. The mutations were found to cause reduced or absent AT-1 expression and abnormal intracellular localization of the protein. We also showed that AT-1 knockdown in HepG2 cells leads to reduced ceruloplasmin secretion, indicating that the low copper in serum is due to reduced ceruloplasmin levels and is not a sign of copper deficiency. The severity of the phenotype implies an essential role of AT-1 in proper posttranslational modification of numerous proteins, without which normal lens and brain development is interrupted. Furthermore, AT-1 defects are a new and important differential diagnosis in patients with low copper and ceruloplasmin in serum.     

Barley ROP binding kinase1 is involved in microtubule organization and in basal penetration resistance to the barley powdery mildew fungus

Certain plant receptor-like cytoplasmic kinases were reported to interact with small monomeric G-proteins of the RHO of plant (ROP; also called RAC) family in planta and to be activated by this interaction in vitro. We identified a barley (Hordeum vulgare) partial cDNA of a ROP binding protein kinase (HvRBK1) in yeast (Saccharomyces cerevisiae) two-hybrid screenings with barley HvROP bait proteins. Protein interaction of the constitutively activated (CA) barley HvROPs CA HvRACB and CA HvRAC1 with full-length HvRBK1 was verified in yeast and in planta. Green fluorescent protein-tagged HvRBK1 appears in the cytoplasm and nucleoplasm, but CA HvRACB or CA HvRAC1 can recruit green fluorescent protein-HvRBK1 to the cell periphery. Barley HvRBK1 is an active kinase in vitro, and activity is enhanced by CA HvRACB or GTP-loaded HvRAC1. Hence, HvRBK1 might act downstream of active HvROPs. Transient-induced gene silencing of barley HvRBK1 supported penetration by the parasitic fungus Blumeria graminis f. sp. hordei, suggesting a function of the protein in basal disease resistance. Transient knockdown of HvRBK1 also influenced the stability of cortical microtubules in barley epidermal cells. Hence, HvRBK1 might function in basal resistance to powdery mildew by influencing microtubule organization.     

Development of a DNA barcoding system for seagrasses: successful but not simple

Seagrasses, a unique group of submerged flowering plants, profoundly influence the physical, chemical and biological environments of coastal waters through their high primary productivity and nutrient recycling ability. They provide habitat for aquatic life, alter water flow, stabilize the ground and mitigate the impact of nutrient pollution. at the coast region. Although on a global scale seagrasses represent less than 0.1% of the angiosperm taxa, the taxonomical ambiguity in delineating seagrass species is high. Thus, the taxonomy of several genera is unsolved. While seagrasses are capable of performing both, sexual and asexual reproduction, vegetative reproduction is common and sexual progenies are always short lived and epimeral in nature. This makes species differentiation often difficult, especially for non-taxonomists since the flower as a distinct morphological trait is missing. Our goal is to develop a DNA barcoding system assisting also non-taxonomists to identify regional seagrass species. The results will be corroborated by publicly available sequence data. The main focus is on the 14 described seagrass species of India, supplemented with seagrasses from temperate regions. According to the recommendations of the Consortium for the Barcoding of Life (CBOL) rbcL and matK were used in this study. After optimization of the DNA extraction method from preserved seagrass material, the respective sequences were amplified from all species analyzed. Tree- and character-based approaches demonstrate that the rbcL sequence fragment is capable of resolving up to family and genus level. Only matK sequences were reliable in resolving species and partially the ecotype level. Additionally, a plastidic gene spacer was included in the analysis to confirm the identification level. Although the analysis of these three loci solved several nodes, a few complexes remained unsolved, even when constructing a combined tree for all three loci. Our approaches contribute to the understanding of the morphological plasticity of seagrasses versus genetic differentiation.     

Identification of marker-trait associations in the German winter barley breeding gene pool (Hordeum vulgare L.)

A genome-wide association mapping approach for grain yield and traits of high agronomic relevance was carried out on basis of a set of 61 six-rowed and 48 two-rowed German winter barley (Hordeum vulgare L.) cultivars representing breeding progress in the period 1959?C2003. Extensive phenotyping was conducted in field trials carried out at 12 locations in 3?years. Heritability was estimated at between 0.45 for grain yield and 0.94 for grains per spike. By using the Illumina Golden Gate Bead Array technology, 833 single nucleotide polymorphisms with an allele frequency higher than 5% were obtained. Linkage disequilibrium on the whole genome extends to 7.35?cM. Based on a mixed linear model approach taking into account the population structure estimated on the basis of 72 simple sequence repeat markers covering the whole barley genome, 91 significant marker-trait associations were detected, corresponding to 48 different genomic regions.     

Bacterial isolates from the bryozoan Membranipora membranacea: influence of culture media on isolation and antimicrobial activity

From specimens of the bryozoan Membranipora membranacea collected in the Baltic Sea, bacteria were isolated on four different media, which significantly increased the diversity of the isolated groups. All isolates were classified according to 16S rRNA gene sequence analysis and tested for antimicrobial properties using a panel of five indicator strains and six different media. Each medium featured a unique set of isolated phylotypes, and a phylogenetically diverse collection of isolates was obtained. A total of 96 isolates were assigned to 49 phylotypes and 29 genera. Only one-third of the members of these genera had been isolated previously from comparable sources. The isolates were affiliated with Alpha- and Gammaproteobacteria, Bacilli, and Actinobacteria. A comparable large portion of up to 22 isolates, i.e., 15 phylotypes, probably represent new species. Likewise, 47 isolates (approximately 50%) displayed antibiotic activities, mostly against grampositive indicator strains. Of the active strains, 63.8 % had antibiotic traits only on one or two of the growth media, whereas only 12.7 % inhibited growth on five or all six media. The application of six different media for antimicrobial testing resulted in twice the number of positive hits as obtained with only a single medium. The use of different media for the isolation of bacteria as well as the variation of media considered suitable for the production of antibiotic substances significantly enhanced both the number of isolates obtained and the proportion of antibiotic active cultures. Thus the approach described herein offers an improved strategy in the search for new antibiotic compounds.