Karyotypes of Pneumocystis carinii from Korean rats.

Molecular karyotyping was applied to Pneumocystis carinii(Pc) from two strains of experimental rats, Sprague Dawley(SD) and Fisher(F), in Korea. Field inversion gel electrophoresis and contour clamped homogeneous electric field electrophoresis resolved 15 chromosomal bands from the Pc. The size of the bands was estimated 270kb to 684kb from SD rats, and 273kb to 713 kb from F rats. The bands of 283 kb from SD rats and of 273 kb from F rats stained more brightly suggesting duplicated bands. Total number of chromosomes was at least 16, and total genomic size was estimated 7 x 10(6) bp. All of the bands from F rats hybridized to the probe of repeated DNA sequences of Pc and the band of 448 kb size was proved to contain rDNA sequences, but Pc. chromosome bands from SD rats showed no reactions to the probes. The 2 different karyotypes of P. carinii from 2 strains of rats were maintained consistently for 2 years.     

The use of oral prostaglandin E2 in the management of intrauterine fetal death

12 otherwise healthy patients with intrauterine fetal death 1 to 6 weeks earlier were treated with oral prostaglandin E₂. 9 of the 12 patients delivered within 48 hours after treatment began. 2 others delivered within 48 hours after unsuccessful treatment ceased. In a third patient the cervix relaxed after treatment, and the uterine contents were removed by curettage. No serious complications, such as hemorrhage occurred. The uterus seemed surprisingly responsive to oral prostaglandin E₂ in cases of intrauterine fetal death.     

Trace analysis of the MIF analogue pareptide in blood plasma by high-performance liquid chromatography and short-wavelength excitation fluorometry

A high-performance liquid chromatographic procedure was developed and applied to analysis of the pharmacologically active MIF analogue pareptide in human plasma. The procedure involves formation of a fluorescent 7-chloro-4-nitrobenzyl-2-oxa-1,3-diazole-(NBD-CI) pareptide derivative followed by separation of the NBD derivative from plasma components on a 30-cm microparticle octadecylsilane bonded column. The separated derivative was quantitated using a short-wavelength excitation fluorometric detector. The detection limit of pareptide in plasma samples was 5 ng or 17 pmoles per ml of plasma. In the absence of plasma, the corresponding on-column detection limit was 0.5 pmoles.     

WDNM1 is Associated with Differentiation and Apoptosis of Mammary Epithelial Cells

In this study, we show that expression of the Westmead DMBA8 nonmetastatic cDNA 1 (WDNM1) gene was increased upon SFM and/or TNFα treatment, with a corresponding increase in apoptotic cells, and gradually decreased following re-stimulation with serum in HC11 mammary epithelial cells. TNFα induced WDNM1 expression showed the NFκB-dependent mechanism since it's expression was abrogated in IκBαM (super-repressor of NFκB)-transfected cells, but not those transfected with control vector. Furthermore, overexpression of WDNM1 suppressed growth and differentiation, and accelerated apoptosis of HC11 cells. Thus, our results demonstrate that WDNM1 gene expression, regulated by the TNFα-NFκB signal pathway, is associated with HC11 cell apoptosis.     

Microbial composition affects the functioning of estuarine sediments

Although microorganisms largely drive many ecosystem processes, the relationship between microbial composition and their functioning remains unclear. To tease apart the effects of composition and the environment directly, microbial composition must be manipulated and maintained, ideally in a natural ecosystem. In this study, we aimed to test whether variability in microbial composition affects functional processes in a field setting, by reciprocally transplanting riverbed sediments between low- and high-salinity locations along the Nonesuch River (Maine, USA). We placed the sediments into microbial ‘cages'' to prevent the migration of microorganisms, while allowing the sediments to experience the abiotic conditions of the surroundings. We performed two experiments, short- (1 week) and long-term (7 weeks) reciprocal transplants, after which we assayed a variety of functional processes in the cages. In both experiments, we examined the composition of bacteria generally (targeting the 16S rDNA gene) and sulfate-reducing bacteria (SRB) specifically (targeting the dsrAB gene) using terminal restriction fragment length polymorphism (T-RFLP). In the short-term experiment, sediment processes (CO₂ production, CH₄ flux, nitrification and enzyme activities) depended on both the sediment''s origin (reflecting differences in microbial composition between salt and freshwater sediments) and the surrounding environment. In the long-term experiment, general bacterial composition (but not SRB composition) shifted in response to their new environment, and this composition was significantly correlated with sediment functioning. Further, sediment origin had a diminished effect, relative to the short-term experiment, on sediment processes. Overall, this study provides direct evidence that microbial composition directly affects functional processes in these sediments.     

Temporal stability and assignment power of adaptively divergent genomic regions between herring (Clupea harengus) seasonal spawning aggregations

Atlantic herring (Clupea harengus), a vital ecosystem component and target of the largest Northwest Atlantic pelagic fishery, undergo seasonal spawning migrations that result in elusive sympatric population structure. Herring spawn mostly in fall or spring, and genomic differentiation was recently detected between these groups. Here we used a subset of this differentiation, 66 single nucleotide polymorphisms (SNPs) to analyze the temporal dynamics of this local adaptation and the applicability of SNP subsets in stock assessment. We showed remarkable temporal stability of genomic differentiation corresponding to spawning season, between samples taken a decade apart (2005 N = 90 vs. 2014 N = 71) in the Gulf of St. Lawrence, and new evidence of limited interbreeding between spawning components. We also examined an understudied and overexploited herring population in Bras d'Or lake (N = 97); using highly reduced SNP panels (N_SNPs > 6), we verified little‐known sympatric spawning populations within this unique inland sea. These results describe consistent local adaptation, arising from asynchronous reproduction in a migratory and dynamic marine species. Our research demonstrates the efficiency and precision of SNP‐based assessments of sympatric subpopulations; and indeed, this temporally stable local adaptation underlines the importance of such fine‐scale management practices.     

Broad spectrum identification of SUMO substrates in melanoma cells

Like phosphorylation, protein sumoylation likely represents a dynamic PTM to alter protein function in support of cell regulatory systems. The broad-spectrum impact of transient or chronic engagement of signal transduction cascades on protein sumoylation has not been explored. Here, we find that epidermal growth factor (EGF) stimulation evokes a rapid alteration in small ubiquitin modifier (SUMO) target selection, while oncogene expression alters steady-state SUMO-protein profiles. A proteomic SUMO target analysis in melanoma cells identified proteins involved in cellular signaling, growth control, and neural differentiation.     

A path from primary protein sequence to ligand recognition

A novel method to organize protein structural information based solely on sequence is presented. The method clusters proteins into families that correlate with the three-dimensional protein structure and the conformation of the bound ligands. This procedure was applied to nicotinamide adenine dinucleotide [NAD(P)]-utilizing enzymes to identify a total of 94 sequence families, 53 of which are structurally characterized. Each of the structurally characterized proteins within a sequence family correlates to a single protein fold and to a common bound conformation of NAD(P). A wide range of structural folds is identified that recognize NAD(P), including Rossmann folds and beta/alpha barrels. The defined sequence families can be used to identify the type and prevalence of NAD(P)-utilizing enzymes in the proteomes of sequenced organisms. The proteome of Mycobacterium tuberculosis was mined to generate a proteome-wide profile of NAD(P)-utilizing enzymes coded by this organism. This enzyme family comprises approximately 6% of the open reading frames, with the largest subgroup being the Rossmann fold, short-chain dehydrogenases. The preponderance of short-chain dehydrogenases correlates strongly with the phenotype of M. tuberculosis, which is characterized as having one of the most complex prokaryotic cell walls.     

Determinants of S. cerevisiae dynein localization and activation: implications for the mechanism of spindle positioning

BACKGROUND: During anaphase in budding yeast, dynein inserts the mitotic spindle across the neck between mother and daughter cells. The mechanism of dynein-dependent spindle positioning is thought to involve recruitment of dynein to the cell cortex followed by capture of astral microtubules (aMTs). RESULTS: We report the native-level localization of the dynein heavy chain and characterize the effects of mutations in dynein regulators on its intracellular distribution. Budding yeast dynein displays discontinuous localization along aMTs, with enrichment at the spindle pole body and aMT plus ends. Loss of Bik1p (CLIP-170), the cargo binding domain of Bik1p, or Pac1p (LIS1) resulted in diminished targeting of dynein to aMTs. By contrast, loss of dynactin or a mutation in the second P loop domain of dynein resulted in an accumulation of dynein on the plus ends of aMTs. Unexpectedly, loss of Num1p, a proposed dynein cortical anchor, also resulted in selective accumulation of dynein on the plus ends of anaphase aMTs. CONCLUSIONS: We propose that, rather than first being recruited to the cell cortex, dynein is delivered to the cortex on the plus ends of polymerizing aMTs. Dynein may then undergo Num1p-dependent activation and transfer to the region of cortical contact. Based on the similar effects of loss of Num1p and loss of dynactin on dynein localization, we suggest that Num1p might also enhance dynein motor activity or processivity, perhaps by clustering dynein motors.