The genome sequence of the gram-positive sugarcane pathogen Leifsonia xyli subsp. xyli

The genome sequence of Leifsonia xyli subsp. xyli, which causes ratoon stunting disease and affects sugarcane worldwide, was determined. The single circular chromosome of Leifsonia xyli subsp. xyli CTCB07 was 2.6 Mb in length with a GC content of 68% and 2,044 predicted open reading frames. The analysis also revealed 307 predicted pseudogenes, which is more than any bacterial plant pathogen sequenced to date. Many of these pseudogenes, if functional, would likely be involved in the degradation of plant heteropolysaccharides, uptake of free sugars, and synthesis of amino acids. Although L. xyli subsp. xyli has only been identified colonizing the xylem vessels of sugarcane, the numbers of predicted regulatory genes and sugar transporters are similar to those in free-living organisms. Some of the predicted pathogenicity genes appear to have been acquired by lateral transfer and include genes for cellulase, pectinase, wilt-inducing protein, lysozyme, and desaturase. The presence of the latter may contribute to stunting, since it is likely involved in the synthesis of abscisic acid, a hormone that arrests growth. Our findings are consistent with the nutritionally fastidious behavior exhibited by L. xyli subsp. xyli and suggest an ongoing adaptation to the restricted ecological niche it inhabits.     

Genetic diversity of Costa Rican populations of the rice planthopper Tagosodes orizicolus (Homoptera: Delphacidae)

Tagosodes orizicolus (Homoptera: Delphacidae) is one of the main constraints of the rice production in the Neotropics. This planthopper produces severe damages as a phloem feeder, causes mechanical injury during oviposition and vectors the rice hoja blanca virus (RHBV). The main objective of this study was to determine the genetic diversity of T. orizicolus populations from three rice growing regions of Costa Rica, using RAPDs. Individuals from Guanacaste, Parrita, San Carlos and Cali-Colombia, as outgroup, were analyzed using the random primers. Phenetic relationships revealed that the Costa Rican populations were clearly separated from Cali-Colombia, sharing less than 25% similarity. Costa Rican populations were divided into two main branches separated at 30% similarity. The first branch included Guanacaste and San Carlos and the second displayed Parrita. In relation to similarity indexes within groups, the Guanacaste cluster showed the highest (over 50%) and Cali-Colombia was the most diverse (28%). The correspondence analysis confirmed the clusters of the phenogram and showed close interactions between the Parrita and San Carlos populations. The genetic separation observed could be the result of the geographic isolation among populations, but it could also be explained by the infection with the rickettsia Wolbachia pipientis. This bacterium causes cytoplasmic incompatibility in its host, which results in non-viable progeny when infected males mate with non-infected females, or when insects hosting different strains of Wolbachia mate. Then, a search for Wolbachia in previously described populations of T orizicolus was initiated. The presence of the bacteria was analyzed by PCR with 16S rDNA-specific primers for Wolbachia. The PCR analyses revealed infections of 86% in the population of San Carlos, 96% in Guanacaste, 37% in Parrita and 100% in Cali-Colombia. Crosses between individuals of T. orizicolus from Parrita and Guanacaste were performed for testing cytoplasmic incompatibility. When infected males were crossed with non-infected females within the same population, a significant reduction in progeny number was obtained as well as when crosses between infected individuals belonging to different populations were performed. These experiments showed cytoplasmic incompatibility not only caused by the presence of Wolbachia within the population, but also by the presence of different strains of the bacteria between populations.     

Diversity of Bacillus thuringiensis strains isolated from coffee plantations infested with the coffee berry borer Hypothenemus hampei

The coffee berry borer Hypothenemus hampei Ferrari (Coleoptera: Scolytidae) was first reported infecting Costa Rican coffee plantations in the year 2000. Due to the impact that this plague has in the economy of the country, we were interested in seeking new alternatives for the biological control of H. hampei, based on the entomopathogenic bacteria Bacillus thuringiensis. A total of 202 B. thuringiensis isolates obtained from Costa Rican coffee plantations infested with H. hampei were analyzed through crystal morphology of the crystal inclusions and SDS-PAGE of 6-endotoxins, while 105 strains were further evaluated by PCR for the presence cry, cyt and vip genes. Most of the Bt strains showed diverse crystal morphologies: pleomorphic (35%), oval (37%), bipyramidal (3%), bipyramidal and oval (12%), bipyramidal, oval and pleomorphic (10%) and bipyramidal, oval and cubic (3%). The SDS-PAGE analyses of the crystal preparations showed five strains with delta-endotoxin from 20 to 40 kDa, six from 40 to 50 kDa, seven from 50 to 60 kDa, 19 from 60 to 70 kDa, 29 from 70 to 100 kDa and 39 from 100-145 kDa. PCR analyses demonstrated that the collection showed diverse cry genes profiles having several genes per strain: 78 strains contained the vip3 gene, 82 the cry2 gene, 45 the cry1 and 29 strains harbored cry3-cry7 genes. A total of 13 strains did not amplified with any of the cry primers used: cry1, cry2, cry3-7, cry5, cry11, cry12 and cry14. Forty-three different genetic profiles were found, mainly due to the combination of cry1A genes with other cry and vip genes. The genetic characterization of the collection provides opportunities for the selection of strains to be tested in bioassays against H. hampei and other insect pests of agricultural importance.     

Prospective study of hepatitis C virus infection in hemodialysis patients by monthly analysis of HCV RNA and antibodies

The aims of this study were to (i) evaluate the prevalence and the incidence of hepatitis C virus (HCV) infection in hemodialysis patients in two different centers in S?o Paulo (Brazil), (ii) determine the time required to detect HCV infection among these patients by serology or PCR, (iii) establish the importance of alanine aminotransferase determination as a marker of HCV infection, and (iv) identify the HCV genotypes in this population. Serum samples were collected monthly for 1 year from 281 patients admitted to hospital for hemodialysis. Out of 281 patients, 41 patients (14.6%) were HCV positive; six patients seroconverted during this study (incidence = 3.1/1000 person-month). In 1.8% (5/281) of cases, RNA was detected before the appearance of antibodies (up to 5 months), and in 1.1% (3/281) of cases, RNA was the unique marker of HCV infection. The genotypes found were 1a, 1b, 3a, and 4a. The presence of genotype 4a is noteworthy, since it is a rare genotype in Brazil. These data pointed out the high prevalence and incidence of HCV infection at hemodialysis centers in Brazil and showed that routine PCR is fundamental for improving the detection of HCV carriers among patients undergoing hemodialysis.     

Functional conservation of subfamilies of putative UDP-N-acetylgalactosamine:polypeptide N-acetylgalactosaminyltransferases in Drosophila, Caenorhabditis elegans, and mammals. One subfamily composed of l(2)35Aa is essential in Drosophila

The completed fruit fly genome was found to contain up to 15 putative UDP-N-acetyl-alpha-d-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-transferase) genes. Phylogenetic analysis of the putative catalytic domains of the large GalNAc-transferase enzyme families of Drosophila melanogaster (13 available), Caenorhabditis elegans (9 genes), and mammals (12 genes) indicated that distinct subfamilies of orthologous genes are conserved in each species. In support of this hypothesis, we provide evidence that distinctive functional properties of Drosophila and human GalNAc-transferase isoforms were exhibited by evolutionarily conserved members of two subfamilies (dGalNAc-T1 (l(2)35Aa) and GalNAc-T11; dGalNAc-T2 (CG6394) and GalNAc-T7). dGalNAc-T1 and novel human GalNAc-T11 were shown to encode functional GalNAc-transferases with the same polypeptide acceptor substrate specificity, and dGalNAc-T2 was shown to encode a GalNAc-transferase with similar GalNAc glycopeptide substrate specificity as GalNAc-T7. Previous data suggested that the putative GalNAc-transferase encoded by l(2)35Aa had a lethal phenotype (Flores, C., and Engels, W. (1999) Proc. Natl. Acad. Sci. U. S. A. 96, 2964-2969), and this was substantiated by sequencing of three lethal alleles l(2)35Aa(HG8), l(2)35Aa(SF12), and l(2)35Aa(SF32). The finding that subfamilies of GalNAc-transferases with distinct catalytic functions are evolutionarily conserved stresses that GalNAc-transferase isoforms may serve unique biological functions rather than providing functional redundancy, and this is further supported by the lethal phenotype of l(2)35Aa.     

Descriptions of the mature spermatozoa of the lizards Crotaphytus bicinctores, Gambelia wislizenii (Crotaphytidae), and Anolis carolinensis (Polychrotidae) (Reptilia, Squamata, Iguania)

The spermatozoa of Crotaphytus bicinctores and Gambelia wislizenii (Crotaphytidae), and Anolis carolinensis (Polychrotidae) exhibit the squamate autapomorphies of a single perforatorium extending anteriorly from the apical tip of the paracrystalline subacrosomal cone, the presence of an epinuclear electron-lucent region, and extension of the fibrous sheath into the midpiece. Crotaphytid sperm differ from those of polychrotids in several respects, including: the structure of the perforatorium, the size of the epinuclear electron-lucent region, aspects of the acrosome complex, the arrangement and structure of intermitochondrial dense bodies, and in the distance the fibrous sheath extends into the midpiece. The sperm of C. bicinctores, G. wislizenii, and A. carolinensis are most similar to those of the agamids and phrynosomatids examined to date. No spermatozoal autapomorphies for Crotaphytidae or Polychrotidae were found. The condition of having the intermitochondrial dense bodies arranged in regular incomplete rings is tentatively defined as a synapomorphy of Iguania (although modified in Chamaeleonidae). Spermatozoal ultrastructure offers no characters that justify the separation of Iguanidae (sensu lato) into several separate families.     

Anti-Influenza Neuraminidase Inhibitor Oseltamivir Phosphate Induces Canine Mammary Cancer Cell Aggressiveness

Oseltamivir phosphate is a widely used anti-influenza sialidase inhibitor. Sialylation, governed by sialyltransferases and sialidases, is strongly implicated in the oncogenesis and progression of breast cancer. In this study we evaluated the biological behavior of canine mammary tumor cells upon oseltamivir phosphate treatment (a sialidase inhibitor) in vitro and in vivo. Our in vitro results showed that oseltamivir phosphate impairs sialidase activity leading to increased sialylation in CMA07 and CMT-U27 canine mammary cancer cells. Surprisingly, oseltamivir phosphate stimulated, CMT-U27 cell migration and invasion capacity in vitro, in a dose-dependent manner. CMT-U27 tumors xenograft of oseltamivir phosphate-treated nude mice showed increased sialylation, namely α2,6 terminal structures and SLe(x) expression. Remarkably, a trend towards increased lung metastases was observed in oseltamivir phosphate-treated nude mice. Taken together, our findings revealed that oseltamivir impairs canine mammary cancer cell sialidase activity, altering the sialylation pattern of canine mammary tumors, and leading, surprisingly, to in vitro and in vivo increased mammary tumor aggressiveness.     

Carotid Intima-Media Thickness at Age 30, Birth Weight,Accelerated Growth during Infancy and Breastfeeding: A Birth Cohort Study in Southern Brazil

Objective

To examine the relationship between carotid intima-media thickness (IMT) at age 30 and birth characteristics, growth during infancy, and breastfeeding duration, among subjects who have been prospectively followed since birth.

Methods and Results

In 1982, all births in the city of Pelotas, southern Brazil, were identified and those children (n = 5,914) whose families lived in the urban area of the city have been followed and evaluated at several time points. The cohort participants were evaluated in 2012–13, and IMT was measured at the posterior wall of the right and left common carotid arteries in longitudinal planes using ultrasound imaging. We obtained valid IMT measurements for 3,188 individuals. Weight-for-age z-score (WAZ) at age 2 years, weight-for-height z-score (WHZ) at age 4, height-for-age z-score (HAZ) at 4 years, WAZ at age 4 and relative conditional weight at 4 years were positively associated with IMT, even after controlling for confounding variables. The beta-coefficient associated with ≥1 s.d. WAZ at age 2 (compared to those with a <–1 s.d.) was 3.62 μm (95% CI 0.86 to 6.38). The beta-coefficient associated with ≥1 s.d. WHZ at 4 (in relation to <–1 s.d) was 3.83 μm (95% CI 0.24 to 7.42). For HAZ at 4, the beta-coefficient for ≥1 s.d. in relation to <–1 s.d. was 4.19 μm (95% CI 1.14 to 7.25). For WAZ at 4, the beta-coefficient associated with ≥1 s.d. in relation to <–1 s.d. was 4.28 μm (95% CI 1.59 to 6.97). The beta-coefficient associated with conditional weight gain at age 2–4 was 1.26 μm (95% CI 0.49 to 2.02).

Conclusion

IMT at age 30 was positively associated with WAZ at age 2 years, WHZ at age 4, HAZ at age 4, WAZ at age 4 and conditional weight gain at age 4 years.