Structural organization, mapping, characterization and evolutionary relationships of CDKN2 gene family members in Xiphophorus fishes

Xiphophorus fishes and their hybrids are used as models for the study of melanoma and other diseases. The cyclin-dependent kinase inhibitor gene family in humans is comprised of four members, including CDKN2A (P16), and dysregulation of this gene is implicated in numerous neoplasms including melanomas. We have investigated the status of the gene family in the southern platyfish X. maculatus. Xiphophorus harbors at least two such loci, which we now term CDKN2A/B and CDKN2D. Both loci map to Xiphophorus linkage group 5, a genomic area that has long been known to harbor the DIFF tumor suppressor locus. Within this report, we report on the complete cloning, genomic exon/intron boundary delineation, linkage mapping and expressional characteristics of Xiphophorus CDKN2D. We also compare and contrast this expression to that of the previously isolated CDKN2AB locus in normal and neoplastic tissues derived from non-hybrid and hybrid fishes. The hypothetical evolutionary relationships of gene family members and their involvement in melanoma is evaluated. In comparison to CDKN2A/B, the RNA expression of Xiphophorus CDKN2D differs in normal tissues and is not associated with melanotic/pathologic tissues, confirming functional divergence between obvious homologues.     

Plasma and urine levels of resistin and adiponectin in chronic kidney disease

BACKGROUND: Subjects with chronic kidney disease (CKD) have an increased risk of developing coronary atherosclerosis. Adipocyte hormones, resistin and adiponectin are implicated in insulin resistance and atherosclerosis. However, few studies in the literature address the role of adipocyte hormones in CKD. The aim of this study was to compare the levels of resistin, adiponectin and other inflammatory markers in subjects with CKD with those of the control subjects. MATERIALS AND METHODS: In a cross-sectional study, we measured basal metabolic panel, fasting lipid panel and levels of glucose, resistin, adiponectin, insulin, C-reactive protein (CRP) and TNF-alpha in 43 subjects with CKD compared with those of 34 control subjects. We also measured the resistin and adiponectin levels in urine samples (16). RESULTS: Subjects with CKD have increased insulin levels and insulin resistance index (IRI). Compared with controls, subjects with CKD had increased levels of resistin (5.12+/-3.2 vs.7.5+/-5.9; p<0.05), CRP (1.7+/-2.2 vs. 5.97+/-6.0; p<0.0005), and TNF-alpha (3.4+/-2.0 vs. 5.2+/-3.5; p<0.005). Resistin levels correlate with CRP and TNF-alpha, even with BMI as a covariate. Although 60% of subjects with CKD have CAD, e plasma levels of adiponectin were not decreased in subjects with CKD compared with controls (17.02+/-9.8 vs. 16.40+/-9.0 with p value 0.78). Urinary adiponectin levels correlate inversely with GFR (r=-0.4; p<0.05) and plasma adiponectin levels (r=0.9; p<0.0001). CONCLUSIONS: Subjects with CKD had normal levels of plasma adiponectin despite the adverse metabolic environment for CAD. In addition, this study demonstrates the relationship between resistin and TNF-alpha in subjects with CKD and suggests that resistin may play a role in the sub-clinical inflammation associated with CKD, suggesting that adiponectin clearance may be decreased as shown by the inverse correlation of urinary adiponectin with GFR.     

<Emphasis Type="Italic">Fusarium</Emphasis> species of the <Emphasis Type="Italic">Gibberella fujikuroi</Emphasis> complex and fumonisin contamination of pearl millet and corn in Georgia,USA

This study was designed to identify and compare the Fusarium species of the Gibberella fujikuroi complex on pearl millet (Pennisetum glaucum (L.) R. Br) and corn (Zea mays L.) crops grown in southern Georgia, and to determine their influence on potential fumonisin production. Pearl millet and corn samples were collected in Georgia in 1996, 1997 and 1998. Three percent of the pearl millet seeds had fungi similar to the Fusarium species of the G. fujikuroi species complex. One hundred and nineteen representative isolates visually similar to the G. fujikuroi species complex from pearl millet were paired with mating population A (Fusarium verticillioides (Sacc.) Nirenberg), mating population D (F. proliferatum (Matsushima) Nirenberg) and mating population F (F. thapsinum (Klittich, Leslie, Nelson and Marasas) tester strains. Successful crosses were obtained with 50.4%, 10.1% and 0.0% of these isolates with the A, D and F tester strains, while 39.5 of the isolates did not form perithecia with any tester strains. Two of the typical infertile isolates were characterized by DNA sequence comparisons and were identified as Fusarium pseudonygamai (Nirenberg and ODonnell), which is the first known isolation of this species in the United States. Based on the pattern of cross-compatibility, conidiogenesis, colony characteristics and media pigmentation, a majority of the infertile isolates belong to this species. Fumonisins FB₁ and FB₂ were not detected in any of the 81 pearl millet samples analyzed. The species of the G. fujikuroi species complex were dominant in corn and were isolated from 84%, 74% and 65% of the seed in 1996, 1997 and 1998, respectively. Representative species of the G. fujikuroi species complex were isolated from 1996 to 1998 Georgia corn survey (162, 104 and 111 isolates, respectively) and tested for mating compatibility. The incidence of isolates belonging to mating population A (F. verticillioides) ranged from 70.2% to 89.5%. Corn survey samples were assayed for fumonisins, and 63% to 91% of the 1996, 1997 and 1998 samples were contaminated. The total amount of fumonisins in the corn samples ranged from 0.6 to 33.3 g/g.     

MMP-9, TIMP-1 and inflammatory cells in sputum from COPD patients during exacerbation

Background

Irreversible airflow obstruction in Chronic Obstructive Pulmonary Disease (COPD) is thought to result from airway remodelling associated with aberrant inflammation. Patients who experience frequent episodes of acute deterioration in symptoms and lung function, termed exacerbations, experience a faster decline in their lung function, and thus over time greater disease severity However the mechanisms by which these episodes may contribute to decreased lung function are poorly understood.This study has prospectively examined changes in sputum levels of inflammatory cells, MMP-9 and TIMP-1 during exacerbations comparing with paired samples taken prior to exacerbation.

Methods

Nineteen COPD patients ((median, [IQR]) age 69 [63 to 74], forced expiratory volume in one second (FEV1) 1.0 [0.9 to1.2], FEV1% predicted 37.6 [27.3 to 46.2]) provided sputa at exacerbation. Of these, 12 were paired with a samples collected when the patient was stable, a median 4 months [2 to 8 months] beforehand.

Results

MMP-9 levels increased from 10.5 μg/g [1.2 to 21.1] prior to exacerbation to 17.1 μg/g [9.3 to 48.7] during exacerbation (P < 0.01). TIMP-1 levels decreased from 3.5 μg/g [0.6 to 7.8] to 1.5 μg/g [0.3 to 4.9] (P = 0.16). MMP-9/TIMP-1 Molar ratio significantly increased from 0.6 [0.2 to 1.1] to 3.6 [2.0 to 25.3] (P < 0.05). Neutrophil, eosinophil and lymphocyte counts all showed significant increase during exacerbation compared to before (P < 0.05). Macrophage numbers remained level. MMP-9 levels during exacerbation showed highly significant correlation with both neutrophil and lymphocyte counts (Rho = 0.7, P < 0.01).

Conclusion

During exacerbation, increased inflammatory burden coincides with an imbalance of the proteinase MMP-9 and its cognate inhibitor TIMP-1. This may suggest a pathway connecting frequent exacerbations with lung function decline.     

Molecular localization of a redox-modulated process regulating plant mitochondrial electron transport

Using in organellar assays, we found that significant tobacco alternative oxidase (AOX) activity is dependent on both reduction of a putative regulatory disulfide bond and the presence of pyruvate, which may interact with a Cys sulfhydryl. This redox modulation and pyruvate activation thus may be important in determining the partitioning of electrons to AOX in vivo. To investigate these regulatory mechanisms, we generated tobacco plants expressing mutated AOX proteins. Mutation of the most N-terminal Cys residue (Cys-126) to an Ala residue produced an AOX that could not be converted to the disulfide-linked form, thus identifying this Cys residue as being responsible for redox modulation. Although this mutation might be expected to produce an AOX with constitutive high activity in the presence of pyruvate, we found it to have minimal in organellar activity in the presence of pyruvate. Nonetheless, the Cys-126 mutation did not appear to have compromised the catalytic function of AOX, given that cells expressing the protein displayed high rates of cyanide-resistant respiration in vivo. The striking difference between in vivo and in organellar results suggests that an additional mechanism(s), as yet unidentified by in organellar assays, may promote activity in vivo. Mutation of the Cys residue nearest the presumptive active site (Cys-176) to an Ala residue did not prevent disulfide bond formation or affect the ability of AOX to be stimulated by pyruvate, indicating that this Cys residue is involved in neither redox modulation nor pyruvate activation.     

Diel movement of smallmouth yellowfish Labeobarbus aeneus in the Vaal River,South Africa

Diel movements of Orange–Vaal smallmouth yellowfish Labeobarbus aeneus (Burchell, 1822) in the Vaal River, South Africa, were determined by externally attaching radio transmitters to 11 adult fish and manually tracking them between March and May 2012. Twenty-four radio telemetry monitoring surveys produced 2 304 diel tracks. At night, yellowfish displayed a preference for slow shallow (<0.3?m s?1, <0.5?m) and fast shallow habitats (>0.3?m s?1, <0.3?m), whereas by day they avoided these habitats, preferring fast deep areas (>0.3?m s?1, >0.3?m). The average total distance of 272?m moved per 24-hour period was three times greater than the diel range, and the average maximum displacement per minute was significantly higher in daytime (4?m) than at night (1.5?m). These findings suggest that L. aeneus is active primarily during the day in fast-flowing, deeper waters, and relatively inactive at night, when it occupies shallower habitats. This behaviour should be further explored to identify causal mechanisms underlying the diel habitat shifts in this species such as water temperature, foraging tactics and/or predator avoidance.     

Inter-Mount Social Interactions During Heterosexual and Homosexual Consortships in Japanese Macaques

In this study, we examined whether female Japanese macaques ( Macaca fuscata ) exhibited male-typical patterns of inter-mount social behaviour during homosexual consortships. Data were collected on heterosexual and homosexual consortships from a population of free-ranging Japanese macaques in Arashiyama, Japan. Inter-mount intervals were defined as the period between two consecutive mounts. A total of 3374 heterosexual inter-mount intervals and 1412 homosexual inter-mount intervals were analysed. We examined nine different categories of inter-mount behaviour. Sex differences between heterosexually consorting males and females existed for three of the inter-mount behaviours we examined (i.e. ventral-to-dorsal orientation, aggression directed toward third party individuals, tree-shaking displays). The subordinate female partners in homosexually consorting pairs exhibited some sex-atypical inter-mount behaviours. This sex-atypicality did not appear to reflect generalized developmental canalization in the direction of a male-typical suite of behaviours. Rather, the observed behavioural sex-atypicality could be best explained in terms of the unique alliance-related dynamics that characterized homosexual consortships in Japanese macaques.     

Influence of light and ambient carbon dioxide concentration on nitrate assimilation by intact barley seedlings

The influence of light, dark, and ambient CO₂ on nitrate assimilation in 8- to 9-day-old barley seedlings was studied. To develop the photosynthetic apparatus fully, the seedlings were grown in nitrogen-free Hoagland solution for 5 days in darkness followed by 3 days in continuous light.