Embryo production from superovulated cattle following insemination of sexed sperm

Two trials were conducted to ascertain fertilization rate, embryo quality and numbers of transferable embryos in superovulated heifers and cows inseminated with sexed sperm. Inseminates contained 2 x 10(6), 10 x 10(6) or 20 x 10(6) total sperm enriched for the X- or Y-chromosome ( approximately 90%) by flow cytometry/cell sorting. Non-sexed inseminates contained 40 x 10(6) total sperm. Donors in each trial were allocated to one of each of the bulls included in that study. Each donor was inseminated with frozen/thawed sperm from the same bull for each treatment in successive courses of superstimulation with twice daily i.m. injections of FSH for 4 d. Heifers and cows were inseminated 12 and 24 h after visually observed standing estrus in Trial 1. In Trial 2, a single timed inseminate was used 70-72 h following PGF(2alpha). Ova/embryos were collected non-surgically 7-7.5 d after insemination. In both trials, fewer ova were fertilized with sexed versus non-sexed treatments and with 2 x 10(6) sexed sperm compared to higher doses (P < 0.05). However, insemination of 20 x 10(6) total sexed sperm of >or=90% purity resulted in similar numbers of transferable embryos of the desired sex compared to that for non-sexed sperm.     

Skeletal muscle Nur77 expression enhances oxidative metabolism and substrate utilization

Mitochondrial dysfunction has been implicated in the pathogenesis of type 2 diabetes. Identifying novel regulators of mitochondrial bioenergetics will broaden our understanding of regulatory checkpoints that coordinate complex metabolic pathways. We previously showed that Nur77, an orphan nuclear receptor of the NR4A family, regulates the expression of genes linked to glucose utilization. Here we demonstrate that expression of Nur77 in skeletal muscle also enhances mitochondrial function. We generated MCK-Nur77 transgenic mice that express wild-type Nur77 specifically in skeletal muscle. Nur77-overexpressing muscle had increased abundance of oxidative muscle fibers and mitochondrial DNA content. Transgenic muscle also exhibited enhanced oxidative metabolism, suggestive of increased mitochondrial activity. Metabolomic analysis confirmed that Nur77 transgenic muscle favored fatty acid oxidation over glucose oxidation, mimicking the metabolic profile of fasting. Nur77 expression also improved the intrinsic respiratory capacity of isolated mitochondria, likely due to the increased abundance of complex I of the electron transport chain. These changes in mitochondrial metabolism translated to improved muscle contractile function ex vivo and improved cold tolerance in vivo. Our studies outline a novel role for Nur77 in the regulation of oxidative metabolism and mitochondrial activity in skeletal muscle.     

Effects of salinity on hard clam (Mercenaria mercenaria) defense parameters and QPX disease dynamics

QPX (Quahog Parasite Unknown) is a protistan parasite affecting hard clams (Mercenaria mercenaria) along the Northeast coast of the United States. The fact that QPX disease epizootics are usually observed in field sites with high salinities led to the general assumption that salinity represents an important factor for disease distribution. This study was designed to investigate the effect of salinity on QPX disease development as well as constitutive and QPX-induced defense factors in M. mercenaria. Naïve and QPX-infected (both experimentally and naturally) clams were submitted to 17 and 30 psu for 4 months. Standard and QPX-specific cellular and humoral defense parameters were assessed after 2 and 4 months. These included total and differential hemocyte counts, reactive oxygen species production, phagocytic activity of hemocytes, lysozyme concentration in plasma, anti-QPX activity in plasma and resistance of hemocytes to cytotoxic QPX extracellular products. Results demonstrated higher QPX-associated mortality in naturally infected clams maintained at high salinity compared to those held at 17 psu. Our findings also showed an increase in mortality following experimental challenge with QPX in clams submitted to 30 psu but not in those held at 17 psu. Constitutive clam defense factors and the response to QPX challenge were also affected by salinity. QPX challenge caused significant but transitory changes in hemolymph parameters that were obvious at 2 months but disappeared at 4 months. Overall, our results show that salinity modulates clam immunity and the progress of QPX disease although its impact appears secondary as compared to findings we reported earlier for temperature.     

Analysis of the gut microbiota in the old order amish and its relation to the metabolic syndrome

Obesity has been linked to the human gut microbiota; however, the contribution of gut bacterial species to the obese phenotype remains controversial because of conflicting results from studies in different populations. To explore the possible dysbiosis of gut microbiota in obesity and its metabolic complications, we studied men and women over a range of body mass indices from the Old Order Amish sect, a culturally homogeneous Caucasian population of Central European ancestry. We characterized the gut microbiota in 310 subjects by deep pyrosequencing of bar-coded PCR amplicons from the V1-V3 region of the 16S rRNA gene. Three communities of interacting bacteria were identified in the gut microbiota, analogous to previously identified gut enterotypes. Neither BMI nor any metabolic syndrome trait was associated with a particular gut community. Network analysis identified twenty-two bacterial species and four OTUs that were either positively or inversely correlated with metabolic syndrome traits, suggesting that certain members of the gut microbiota may play a role in these metabolic derangements.     

Proteomic analysis of the venom of Heterometrus longimanus (Asian black scorpion)

Venoms have evolved over millions of years into potent cocktails of bioactive peptides and proteins. These compounds can be of great value to the pharmaceutical industry for numerous clinical applications. In this study, a novel proteomic - bioinformatic approach was utilised, where chromatography followed by gel electrophoresis was utilised to separate the venom peptides/proteins of Heterometrus longimanus (Asian black scorpion). Purified peptides were analysed by tandem mass spectrometry, de novo sequenced and then homology matched against known peptides in the Swiss-Prot protein database. Numerous potentially biologically active peptide matches were discovered, and a simple scoring system applied to putatively assign functions to the peptides. As a validation of this approach, the functional composition of the experimentally derived proteome is similar to that of other scorpions, and contains a potent mix of toxins, antimicrobials and ionic channel inhibitors.     

A high confidence, manually validated human blood plasma protein reference set

Background

The immense diagnostic potential of human plasma has prompted great interest and effort in cataloging its contents, exemplified by the Human Proteome Organization (HUPO) Plasma Proteome Project (PPP) pilot project. Due to challenges in obtaining a reliable blood plasma protein list, HUPO later re-analysed their own original dataset with a more stringent statistical treatment that resulted in a much reduced list of high confidence (at least 95%) proteins compared with their original findings. In order to facilitate the discovery of novel biomarkers in the future and to realize the full diagnostic potential of blood plasma, we feel that there is still a need for an ultra-high confidence reference list (at least 99% confidence) of blood plasma proteins.

Methods

To address the complexity and dynamic protein concentration range of the plasma proteome, we employed a linear ion-trap-Fourier transform (LTQ-FT) and a linear ion trap-Orbitrap (LTQ-Orbitrap) for mass spectrometry (MS) analysis. Both instruments allow the measurement of peptide masses in the low ppm range. Furthermore, we employed a statistical score that allows database peptide identification searching using the products of two consecutive stages of tandem mass spectrometry (MS3). The combination of MS3 with very high mass accuracy in the parent peptide allows peptide identification with orders of magnitude more confidence than that typically achieved.

Results

Herein we established a high confidence set of 697 blood plasma proteins and achieved a high 'average sequence coverage' of more than 14 peptides per protein and a median of 6 peptides per protein. All proteins annotated as belonging to the immunoglobulin family as well as all hypothetical proteins whose peptides completely matched immunoglobulin sequences were excluded from this protein list. We also compared the results of using two high-end MS instruments as well as the use of various peptide and protein separation approaches. Furthermore, we characterized the plasma proteins using cellular localization information, as well as comparing our list of proteins to data from other sources, including the HUPO PPP dataset.

Conclusion

Superior instrumentation combined with rigorous validation criteria gave rise to a set of 697 plasma proteins in which we have very high confidence, demonstrated by an exceptionally low false peptide identification rate of 0.29%.     

Projection structure of a member of the amino acid/polyamine/organocation transporter superfamily

The L-arginine/agmatine antiporter AdiC is a key component of the arginine-dependent extreme acid resistance system of Escherichia coli. Phylogenetic analysis indicated that AdiC belongs to the amino acid/polyamine/organocation (APC) transporter superfamily having sequence identities of 15-17% to eukaryotic and human APC transporters. For functional and structural characterization, we cloned, overexpressed, and purified wild-type AdiC and the point mutant AdiC-W293L, which is unable to bind and consequently transport L-arginine. Purified detergent-solubilized AdiC particles were dimeric. Reconstitution experiments yielded two-dimensional crystals of AdiC-W293L diffracting beyond 6 angstroms resolution from which we determined the projection structure at 6.5 angstroms resolution. The projection map showed 10-12 density peaks per monomer and suggested mainly tilted helices with the exception of one distinct perpendicular membrane spanning alpha-helix. Comparison of AdiC-W293L with the projection map of the oxalate/formate antiporter from Oxalobacter formigenes, a member from the major facilitator superfamily, indicated different structures. Thus, two-dimensional crystals of AdiC-W293L yielded the first detailed view of a transport protein from the APC superfamily at sub-nanometer resolution.     

Novel role of the muskelin-RanBP9 complex as a nucleocytoplasmic mediator of cell morphology regulation

The evolutionarily conserved kelch-repeat protein muskelin was identified as an intracellular mediator of cell spreading. We discovered that its morphological activity is controlled by association with RanBP9/RanBPM, a protein involved in transmembrane signaling and a conserved intracellular protein complex. By subcellular fractionation, endogenous muskelin is present in both the nucleus and the cytosol. Muskelin subcellular localization is coregulated by its C terminus, which provides a cytoplasmic restraint and also controls the interaction of muskelin with RanBP9, and its atypical lissencephaly-1 homology motif, which has a nuclear localization activity which is regulated by the status of the C terminus. Transient or stable short interfering RNA–based knockdown of muskelin resulted in protrusive cell morphologies with enlarged cell perimeters. Morphology was specifically restored by complementary DNAs encoding forms of muskelin with full activity of the C terminus for cytoplasmic localization and RanBP9 binding. Knockdown of RanBP9 resulted in equivalent morphological alterations. These novel findings identify a role for muskelin–RanBP9 complex in pathways that integrate cell morphology regulation and nucleocytoplasmic communication.