Crystal structure of tRNA m1A58 methyltransferase TrmI from Aquifex aeolicus in complex with S-adenosyl-l-methionine

The N ¹-methyladenosine residue at position 58 of tRNA is found in the three domains of life, and contributes to the stability of the three-dimensional L-shaped tRNA structure. In thermophilic bacteria, this modification is important for thermal adaptation, and is catalyzed by the tRNA m¹A58 methyltransferase TrmI, using S-adenosyl-l-methionine (AdoMet) as the methyl donor. We present the 2.2 Å crystal structure of TrmI from the extremely thermophilic bacterium Aquifex aeolicus, in complex with AdoMet. There are four molecules per asymmetric unit, and they form a tetramer. Based on a comparison of the AdoMet binding mode of A. aeolicus TrmI to those of the Thermus thermophilus and Pyrococcus abyssi TrmIs, we discuss their similarities and differences. Although the binding modes to the N6 amino group of the adenine moiety of AdoMet are similar, using the side chains of acidic residues as well as hydrogen bonds, the positions of the amino acid residues involved in binding are diverse among the TrmIs from A. aeolicus, T. thermophilus, and P. abyssi.     

NaturalMycoplasma arthritidis infection in mice

B6C3F₁ mice from a hybrid production colony frequently were serologically positive by enzyme-linked immunosorbent assay (ELISA) and consistently negative by culture forMycoplasma pulmonis. Subsequently, 162 mice were obtained and intensively studied using an expanded group of cultural procedures, ELISA, and histopathology. Lesions attributable to mycoplasma infection were not found, butMycoplasma arthritidis was isolated from 20 mice. TheM. pulmonis ELISA was positive (IgM, IgG, or both) in 113 mice. Selected sera were tested simultaneously in both theM. pulmonis ELISA and in an ELISA usingM. arthritidis antigen, and were found to be positive in both the IgM and IgG classes in both ELISAs. Thus, cross-reacting antibody was produced in mice naturally infected withM. arthritidis, confirming previous observations based on experimental infections. To our knowledge, this is the first report of naturalM. arthritidis infection in laboratory mice.     

On the carrying behaviour of basic South American primates

InCallithrix, Saguinus, Aotus, andCallicebus other group members than the mother participate in infant care. Differences among these species are obvious in respect to the time of being off any caregiver, and in respect to the carrying position (Aotus andCallicebus). Alloparental care, a basic behaviour pattern in these species, has evolved from the parking behaviour of the prosimians. The infants are «parked» at other group members.     

Predicted effects of increasing salinity on the crustacean zooplankton community of Pyramid Lake,Nevada

Since 1933 the salinity of Pyramid Lake, Nevada, U.S.A., has increased 32% to nearly 5.5‰. We tested the hypothesis that further increases of 1.5 to 2 times (1.5× to 2×) its present salinity would significantly reduce species richness and alter population structures of the existing crustacean zooplankton community. Three strategies were applied: in addition to monitoring zooplankton in semicontrolled indoor microcosms at 1×, 1.5× and 2× and conducting range-finding, acute, and chronic salinity bioassays, the present zooplankton community of Walker Lake (2×) was compared with that existing in Pyramid Lake (1×). Ceriodaphnia quadrangula and Diaphanosoma leuchtenbergianum, both collected from Pyramid Lake, were lacking in Walker Lake. Populations of Cyclops vernalis were significantly lower and those of Diaptomus sicilis and Moina hutchinsoni were significantly higher in Walker Lake than in Pyramid Lake. Densities of Ceriodaphnia and Cyclops were low in microcosms at salinities > 1×. Diaphanosoma could not be maintained in microcosms, regardless of salinity. Numbers of Diaptomus and Moina in microcosms were proportional to salinity level. Short-term LC50 salinities (‰) were as follows: Diaphanosoma, 6.5; Ceriodaphnia, 7.1; Diaptomus, 13.3; Cyclops, 14.8; and Moina, 17.8. Multiple-generation, chronic bioassays were run only on Cyclops and Diaptomus. Three generations of Cyclops were produced at salinities of 4.0 to 8.5‰, but not at 9.8‰ or higher. Diaptomus was unable to complete three generations at salinities ?9.6‰. We speculate that high salinity in Walker Lake may indirectly benefit Diaptomus by negatively affecting predatory Cyclops, and benefit Moina by causing extinction of competing salinity-intolerant Diaphanosoma and Ceriodaphnia. Except for the response of Diaptomus, results from bioassays were in general agreement with results from microcosms and with field data. Untested predator-prey interactions could be responsible for the apparent discrepancy.     

Possible Effects of Glyphosate on Mucorales Abundance in the Rumen of Dairy Cows in Germany

Glyphosate (N-phosphonomethyl glycine) is registered as a herbicide for many food and non-food crops, as well as non-crop areas where total vegetation control is desired. Glyphosate influences the soil mycobiota; however, the possible effect of glyphosate residues in animal feed (soybean, corn, etc.) on animal mycobiota is almost unknown. Accordingly, the present study was initiated to investigate the mycological characteristics of dairy cows in relationship to glyphosate concentrations in urine. A total of 258 dairy cows on 14 dairy farms in Germany were examined. Glyphosate was detected in urine using ELISA. The fungal profile was analyzed in rumen fluid samples using conventional microbiological culture techniques and differentiated by MALDI-TOF mass spectrometry. LPS-binding protein (LBP) and antibodies (IgG1, IgG2, IgA, and IgM) against fungi were determined in blood using ELISA. Different populations of Lichtheimia corymbifera, Lichtheimia ramosa, Mucor, and Rhizopus were detected. L. corymbifera and L. ramosa were significantly more abundant in animals containing high glyphosate (>40 ng/ml) concentrations in urine. There were no significant changes in IgG1 and IgG2 antibodies toward isolated fungi that were related to glyphosate concentration in urine; however, IgA antibodies against L. corymbifera and L. ramosa were significantly lower in the higher glyphosate groups. Moreover, a negative correlation between IgM antibodies against L. corymbifera, L. ramosa, and Rhizopus relative to glyphosate concentration in urine was observed. LBP also was significantly decreased in animals with higher concentrations of glyphosate in their urine. In conclusion, glyphosate appears to modulate the fungal community. The reduction of IgM antibodies and LBP indicates an influence on the innate immune system of animals.     

Expression status of let-7a and miR-335 among breast tumors in patients with and without germ-line BRCA mutations

The genetic factors of cancer predisposition remain elusive in the majority of familial and/or early-onset cases of breast cancer (BC). This type of BC is promoted by germ-line mutations that inactivate BRCA1 or BRCA2. On the other hand, recent studies have indicated that alterations in the levels of miRNA expression are linked to this disease. Although BRCA1 and BRCA2 gene mutations have been reported to commonly lead to alterations in genes that encode cancer-related proteins, little is known regarding the putative impact of these mutations on noncoding miRNAs. In the present study, we aimed to determine whether miRNA dysregulation is involved in the pathogenesis of BRCA-mutated BC. An expression analysis of 14 human miRNAs previously shown to be related to BC diagnosis, prognosis, and drug resistance was conducted using tissues from 60 familial and/or early-onset patients whose peripheral blood samples had been screened for BRCA1 and BRCA2 mutations through sequence analysis. Let-7a and miR-335 expression levels were significantly downregulated in the tumors of patients with a BRCA mutation compared with those of patients without a BRCA mutation (P = 0.04 and P = 0.02, respectively). Our results defined the associations between the expression status of let-7a and miR-335 and BRCA mutations. The expression analysis of these miRNAs might be used as biomarkers of the BRCA mutation status of early-onset and/or familial BC.     

Molecular evidence to reconcile taxonomic instability in mahseer species (Pisces: Cyprinidae) of India

The mahseers are an important group of fishes endemic to Asia with most species considered threatened. Conservation plans to save declining wild populations are hindered by unstable taxonomy, and detailed systematic review could form a solid platform for future management and conservation. D-loop and cytochrome c oxidase I (COI) mtDNA sequences were examined in nine mahseer species of Tor, Neolissochilus, and Naziritor. Pseudogenes amplified in a portion of the species limited the utility of the D-loop region. ABGD analysis, NJ, ML, and MP methods and genetic distance (TrN?+?I?+?G) using COI data revealed concordant species delimiting patterns. The three genera were monophyletic, separated as distinct clades (TrN?+?I?+?G 0.064 to 0.106), and Naziritor was flagged as a separate genus, distinct from Puntius (TrN?+?I?+?G 0.196). Out of seven nominal species known for Tor cogeners from India, only five were recovered with mtDNA data (TrN?+?I?+?G 0.000 to 0.037) and two species could not be distinguished with the molecular data set employed. Tor mosal, synonymized as Tor putitora, was rediscovered as a distinct species (TrN?+?I?+?G 0.031) based on its type locality. Tor mussulah was confirmed as a separate species (TrN?+?I?+?G 0.019 to 0.026). Two valid species, Tor macrolepis and T. mosal mahanadicus, were not distinct from T. putitora (TrN?+?I?+?G 0.00). The high divergence with mtDNA data failed to validate T. mosal mahanadicus as a subspecies of T. mosal (TrN?+?I?+?G 0.031). Morphological outliers discovered within the distribution range of Tor tor (TrN?+?I?+?G 0.022 to 0.025) shared the same lineage with T. putitora (TrN?+?I?+?G 0.002 to 0.005), indicating a new extended distribution of the Himalayan mahseer T. putitora in the rivers of the Indian central plateau. The findings indicate the need for integrating molecular and morphological tools for taxonomic revision of the Tor and Naziritor genera, so that taxa are precisely defined for accurate in situ and ex situ conservation decisions.     

Expression profile of MAGI2 gene as a novel biomarker in combination with major deregulated genes in prostate cancer

Complex molecular changes that occur during prostate cancer (PCa) progression have been described recently. Whole genome sequencing of primary PCa samples has identified recurrent gene deletions and rearrangements in PCa. Specifically, these molecular events disrupt the gene loci of phosphatase and tensin homolog (PTEN) and membrane-associated guanylate kinase inverted-2 (MAGI2). In the present study, we analyzed the expression profile of MAGI2 gene in a cohort of clinical PCa (n = 45) and benign prostatic hyperplasia (BPH) samples (n = 36) as well as three PCa cell lines. We also studied the expression of PCa-related genes, including PTEN, NKX3.1, SPINK1, DD3, AMACR, ERG, and TMPRSS2-ERG fusion in the same samples. The expression of MAGI2 mRNA was significantly down-regulated in PC3, LNCaP and DU-145 PCa cell lines (p = 0.000), and also in clinical tumor samples (Relative expression = 0.307, p = 0.002, [95 % CI 0.002–12.08]). The expression of PTEN, NKX3.1, SPINK1, DD3, and AMACR genes was significantly deregulated in prostate tumor samples (p range 0.000–0.044). A significant correlation was observed between MAGI2 and NKX3.1 expression in tumor samples (p = 0.006). Furthermore, the inclusion of MAGI2 in the gene panel improved the accuracy for discrimination between PCa and BPH samples with the sensitivity and specificity of 0.88 [CI 0.76–0.95] and 0.83 [CI 0.68–0.92], respectively. The data presented here suggest that MAGI2 gene can be considered as a novel component of gene signatures for the detection of PCa.     

Abnormalities of blood selenium and glutathione peroxidase activity in patients with acquired immunodeficiency syndrome and aids-related complex

Severe protein-calorie malnutrition is common in patients with AIDS and could contribute to the progressive deterioration characteristic of that disease. Selenium deficiency could also have a negative impact on immune function and other organ functions vital for recovery from infectious diseases. Therefore, to assess any role for selenium in AIDS, we determined plasma and erythrocyte selenium levels and glutathione peroxidase activity in 13 patients with AIDS compared to 8 patients with AIDS-related complex (ARC) and 14 healthy controls. Plasma selenium levels were significantly reduced in AIDS patients compared to controls (p<.0001) and to ARC (p<.02). Erythrocyte selenium levels in both AIDS and ARC were also reduced compared to controls (p<.02), but not to each other. Glutathione peroxidase activity in AIDS was 28.9±1.4 U/g Hb vs 38.4±6.9 in ARC (p=NS) and 52.3±1.7 in controls (p<.0001 vs AIDS;p<.02 vs ARC). When all groups were combined, there were significant correlations between total lymphocyte count and both plasma selenium (r=.53;p<.002) and erythrocyte glutathione peroxidase activity (r=.65;p<.0001). In addition, strong correlations were noted between plasma selenium and serum albumin (r=.68;p<.0001), plasma selenium and glutathione peroxidase (r=.77;p<.0001), and glutathione peroxidase and hematocrit (r=.66;p<.0001). In AIDS or ARC, no correlations between selenium with disease duration or weight loss were present. We conclude that, in comparison to normals, patients manifesting infection with human immunodeficiency virus have evidence of selenium deficiency as determined by diminished plasma and erythrocyte levels and glutathione peroxidase activity. These abnormalities are most marked in patients with AIDS, but are also present in patients with AIDS-related complex. Selenium deficiency has important implications for the progression and pathogenesis of clinical disease in AIDS.     

Species ofIchneumonidae [Hym.], parasites of some lepidopterous pests of lucerne in Romania

Eleven species ofIchneumonidae were identified as parasites of lepidopterous pests of lucerne. All of the parasitized Lepidoptera are new host records for theseIchneumonidae andDiadegma variegata Szépl. is a species of parasite new to Romania.