Dual function of Arabidopsis glucan synthase-like genes GSL8 and GSL10 in male gametophyte development and plant growth

Members of the glucan synthase-like (GSL) family are believed to be involved in synthesis of the cell-wall component callose in specialized locations throughout the plant. We identified two members of the Arabidopsis GSL gene family, GSL8 and GSL10 , that are independently required for male gametophyte development and plant growth. Analysis of gsl8 and gsl10 mutant pollen during development revealed specific malfunctions associated with asymmetric microspore division. GSL8 and GSL10 are not essential for normal microspore growth and polarity, but play a role in entry of microspores into mitosis. Impaired function of GSL10 also leads to perturbation of microspore division symmetry, irregular callose deposition and failure of generative-cell engulfment by the cytoplasm of the vegetative cell. Silencing of GSL8 or GSL10 in transgenic lines expressing gene-specific dsRNAi constructs resulted in a dwarfed growth habit, thereby revealing additional and independent wild-type gene functions for normal plant growth.     

New dyrosaurid crocodylomorph and evidences for faunal turnover at the K-P transition in Brazil

The discovery of a new dyrosaurid crocodylomorph from the well-dated Palaeocene deposits of northeastern Brazil sheds new light on the evolutionary history of this extinct group of marine crocodylomorphs that have survived the Cretaceous-Palaeogene (K-P) extinction crisis. Guarinisuchus munizi, the most complete member of this group collected in South America so far, is closely related to the African forms, and this fact suggests that dyrosaurids had crossed the Atlantic Ocean before the K-P boundary and dispersed from there to North America and other parts of South America. This discovery also suggests that on the coast of northeastern Brazil, dyrosaurids replaced the pre-existing Late Cretaceous fauna of diversified mosasaurs, a group of marine lizards, after the K-P extinction event, becoming the main predators, together with sharks, in shallow marine Palaeocene environments. More detailed stratigraphic records and detailed dating of the deposits with dyrosaurids are necessary to correlate this particular pattern found in the ancient northeastern Brazilian coast within the evolution of the group, especially in Africa.     

Association of smoking behavior with an odorant receptor allele telomeric to the human major histocompatibility complex

Smoking behavior has been associated in two independent European cohorts with the most common Caucasian human leukocyte antigen (HLA) haplotype (A1-B8-DR3). We aimed to test whether polymorphic members of the two odorant receptor (OR) clusters within the extended HLA complex might be responsible for the observed association, by genotyping a cohort of Hungarian women in which the mentioned association had been found. One hundred and eighty HLA haplotypes from Centre d'Etude du Polymorphisme Humain families were analyzed in silico to identify single-nucleotide polymorphisms (SNPs) within OR genes that are in linkage disequilibrium with the A1-B8-DR3 haplotype, as well as with two other haplotypes indirectly linked to smoking behavior. A nonsynonymous SNP within the OR12D3 gene (rs3749971(T)) was found to be linked to the A1-B8-DR3 haplotype. This polymorphism leads to a (97)Thr --> Ile exchange that affects a putative ligand binding region of the OR12D3 protein. Smoking was found to be associated in the Hungarian cohort with the rs3749971(T) allele (p = 1.05 x 10(-2)), with higher significance than with A1-B8-DR3 (p = 2.38 x 10(-2)). Our results link smoking to a distinct OR allele, and demonstrate that the rs3749971(T) polymorphism is associated with the HLA haplotype-dependent differential recognition of cigarette smoke components, at least among Caucasian women.     

Nest volatiles as modulators of nestmate recognition in the ant Camponotus fellah

When ants from alien colonies encounter each other the stereotypic reaction is usually one of aggressive behavior. It has been shown that factors such as queen-derived cues or nest-odors modulate this reaction. Here we examined whether nest volatiles affect nestmate recognition by observing the reaction of nestmates towards individual workers under one of four regimes: completely isolated; isolated but receiving a constant airflow from the mother colony; as previous but with the passage of nest volatiles towards the isolated ants blocked by adsorption on a SuperQ column; or reversed airflow direction-from the isolated ants to the nest interior. Ants that had been completely isolated for three weeks were subjected to aggressive behavior, but not those that had continued to receive airflow from the mother colony. Adsorbing the nest volatiles from the airflow by SuperQ abolished this difference, with these ants now also being subjected to aggression, indicating that nest volatiles can modulate nestmate recognition. Reverse airflow also reduced the level of aggression but to a lesser extent than airflow directed from the mother colony. In queenless colonies the overall aggression was reduced under all regimes, and there was no effect of flow, suggesting that the volatiles involved are queen-borne. The SuperQ adsorbed volatiles originated from Dufour's gland secretions of both workers and queen, implicating them in the process. Cuticular hydrocarbon profiles were not affected by exposure to nest volatiles, suggesting that the latter either constitute part of the recognition cues or affect worker behavior via a different, as yet elusive mechanism.     

Elektronenmikroskopische Beobachtungen zum Chromosomenbau

Ohne ZusammenfassungHerrn Prof. Dr.Lothar Geitler in Verehrung zum 70. Geburtstag.     

Whole-body scanning PCR; a highly sensitive method to study the biodistribution of mRNAs,noncoding RNAs and therapeutic oligonucleotides

Efficient tissue-specific delivery is a crucial factor in the successful development of therapeutic oligonucleotides. Screening for novel delivery methods with unique tissue-homing properties requires a rapid, sensitive, flexible and unbiased technique able to visualize the in vivo biodistribution of these oligonucleotides. Here, we present whole body scanning PCR, a platform that relies on the local extraction of tissues from a mouse whole body section followed by the conversion of target-specific qPCR signals into an image. This platform was designed to be compatible with a novel RT-qPCR assay for the detection of siRNAs and with an assay suitable for the detection of heavily chemically modified oligonucleotides, which we termed Chemical-Ligation qPCR (CL-qPCR). In addition to this, the platform can also be used to investigate the global expression of endogenous mRNAs and non-coding RNAs. Incorporation of other detection systems, such as aptamers, could even further expand the use of this technology.     

KRT8, FAF1 and PTH1R gene polymorphisms are associated with leg weakness traits in pigs

The liability to lesions of dysfunctions of bone and joints in pigs, summarized as leg weakness and mostly expressed as osteochondrosis, is an animal welfare and economic issue in pig production. The objective of this study was to identify polymorphisms in the functional and positional candidate genes keratin 8 (KRT8), Fas-associated factor 1 (FAF1) and parathyroid hormone type I receptor (PTH1R) and to evaluate their association with leg weakness traits. Therefore, osteochondrosis lesions were scored in animals of a Duroc × Pietrain F2 population (DuPi; n = 310) and commercial herds of the breed Large White (n = 298). In addition, bone mineralization traits were observed in DuPi population. SNPs were identified in genes KRT8 (g.8,039G > A), FAF1 (g.380,914T > C) and PTH1R (c.1,672C > T). KRT8 showed significant association with bone mineral density and content (P ≤ 0.05). FAF1 was association with OC lesions score of all joints inspected (P ≤ 0.05). PTH1R showed significant dominance effects on OC lesion scores of the distal femur articular cartilage (P = 0.01) and epiphysis of the distal ulna (P = 0.05) as well as sums of scores of all joints (OCsum, P = 0.04) and assignment to groups of either severely or gently affected animals (OCcat, P = 0.01). This study reveals clear genetic-statistical evidence for a link of KRT8, FAF1 and PTH1R with some of leg weakness related traits in pigs.