Allelic heterogeneity of Crooked Tail Syndrome: result of balancing selection?

We report the identification of a second loss-of-function mutation (c.1906T>C) in the bovine MRC2 gene causing the Crooked Tail Syndrome in Belgian Blue Cattle. We demonstrate that the ensuing substitution of the highly conserved Cysteine 636 with Arginine causes illegitimate receptor oligomerization, which is predicted to impair function of the MRC2 encoded protein, Endo180. We propose that this second MRC2 mutation was selected by breeders as a result of its favourable effect on muscularity in heterozygotes.

Comparative studies on the certification of reference materials by ICPMS and TIMS using isotope dilution procedures.

A comparison of different isotope dilution mass spectrometric (IDMS) procedures using inductively coupled plasma mass spectrometry (ICPMS) and thermal ionization mass spectrometry (TIMS) was carried out to examine the degree of equivalence between the used procedures in terms of requirements for reference material certification. The comparison was based on the measurement results and their uncertainties. The sample used in this study is a pure zinc metal to be certified by the Bureau Communie de Référence (BCR) for amount contents of different trace elements. This study focuses on cadmium and thallium. The TIMS values contributed to the certified values. To guarantee identical conditions as far as possible for the procedures under investigation, the samples were split into subsamples after spiking and digestion took place. Thus, every IDMS procedure started with an identical set of samples. In total, four different IDMS procedures and one external calibration procedure using internal standardization as an example of routine analysis were applied. The IDMS procedures divide in a group with and a group without trace/matrix separation. Multicollector TIMS (TI-MC-MS) and multicollector ICPMS (ICP-MC-MS) were used in combination with trace/matrix separation, whereas quadrupole ICPMS (ICP-QMS) and ICP-MC-MS were also applied to nonseparated samples. All IDMS results agree well within their combined uncertainties, while some results from the external calibration procedure do not. IDMS results obtained by ICPMS without separation are comparable to those obtained by TI-MC-MS with separation regarding precision and accuracy. The smallest uncertainties were achieved using ICP-MC-MS in combination with trace/matrix separation.

Xwig1, a novel putative endoplasmic reticulum protein expressed during epithelial morphogenesis and in response to embryonic wounding.

In a subtractive differential screening, we identified a novel gene with interesting characteristics, termed Xenopus wounding induced gene 1 (Xwig1). Xwig1 encodes a novel protein of 912 amino acids containing 13 putative transmembrane segments and an evolutionarily conserved carboxy-terminal domain. Protein localization studies revealed that Xwig1 is anchored in cytoplasmic structures, presumably the endoplasmic reticulum. Expression is largely confined to epithelial cells in regions that undergo morphogenetic processes, such as blastopore closure, hindgut closure, dorsal closure and optic vesicle invagination. Interestingly, Xwig1 transcription is activated in response to embryonic epidermal wounding. The wounding-induced transcription occurs downstream of the transient phosphorylation of extracellular signal-regulated protein kinases and is in part mediated by Elk-1, but independent of dissection-induced FGF signalling. Thus, Xwig1 provides a molecular link between epithelial morphogenesis and wound healing.

Xgravin-like (Xgl), a novel putative a-kinase anchoring protein (AKAP) expressed during embryonic development in Xenopus.

A-kinase anchoring proteins (AKAPs) are a heterogeneous family of scaffolding proteins that regulate the compartmentalization of signaling components, in particular that of the broad specificity kinase PKA. Here we describe the identification of a new member of this gene family, termed Xenopus gravin-like (Xgl), which encodes a highly acidic protein of 268 kDa that shares extensive homology with human Gravin and murine SSeCKS. Xgl is zygotically expressed in a highly dynamic fashion. During gastrulation Xgl is expressed in posterior mesoderm of the dorsal blastopore lip. During neurulation expression is transiently detected in the forebrain, two bilateral neuroectodermal stripes and the notochord. At tailbud stages expression commences in the mandibular neural crest and the roof of the spinal cord from where neural crest cells migrate into the intersomitic region. In addition expression is detected in the heart and the anterior aspect of the chordoneural hinge.

Contribution of ICP-IDMS to the certification of antimony implanted in a silicon wafer--comparison with RBS and INAA results.

A thin-layer reference material for surface and near-surface analytical methods was produced and certified. The surface density of the implanted Sb layer was determined by Rutherford backscattering spectrometry (RBS), instrumental neutron activation analysis (INAA), and inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) equipped with a multi-collector. The isotopic abundances of Sb (121Sb and 123Sb) were determined by multi-collector ICP-MS and INAA. ICP-IDMS measurements are discussed in detail in this paper. All methods produced values traceable to the SI and are accompanied by a complete uncertainty budget. The homogeneity of the material was measured with RBS. From these measurements the standard uncertainty due to possible inhomogeneities was estimated to be less than 0.78% for fractions of the area increments down to 0.75 mm2 in size. Excellent agreement between the results of the three different methods was found. For the surface density of implanted Sb atoms the unweighted mean value of the means of four data sets is 4.81 x 10(16) cm(-2) with an expanded uncertainty (coverage factor k = 2) of 0.09 x 10(16) cm(-2). For the isotope amount ratio R (121Sb/123Sb) the unweighted mean value of the means of two data sets is 1.435 with an expanded uncertainty (coverage factor k = 2) of 0.006.

[The saccharin test in the pediatric broncho-pneumonologic outpatient clinic. A noninvasive screening method for the assessment of ciliary function of the respiratory tract in children]. / Der Saccharin-Test im pädiatrisch-bronchopneumologischen Dispensaire. Eine nichtinvasive Screeningmethode zur Beurteilung der Zilienfunktion des Respirationstraktes bei Kindern.

The Saccharin test is a non-dangerous, inexpensive, suitable and repeatable method for assessing the mucociliary function of the respiratory epithelium. A small quantity of Saccharin (R) is deposited on the inferior nasal concha; the chemical agent will be transported by the respiratory epithelium (kinocilia) from the nasopharynx to the oropharynx and can be tasted here as "sweet". The time interval between the deposition of Saccharin and the "sweet" taste is the "nasal mucociliary transport time (nmctt)"; data in minutes. In 381 children (age: 3-17 years) we found an average nmctt of 6.6 (+/- 4.8) min (healthy controls) and 8.8 (+/- 5.2) min resp. (CNSRD children). A nmctt longer than 30 min leads one to suspect disturbances of the mucociliary function, the aetiology of which can be analysed by mucosa biopsy and subsequent examination under the electron microscope. We hold the view that Saccharin test is an essential part of the diagnostic program for children suffering from CNSRD; after 3 tests the mucociliary function can be evaluated correctly. The test can be used both for diagnosing the aetiology of respiratory diseases and for the assessment of the efficiency of therapeutic and prophylactic measures.