Genome of Herbaspirillum seropedicae strain SmR1, a specialized diazotrophic endophyte of tropical grasses.

The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme--GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

Chromosome alterations associated with positive and negative lymph node involvement in breast cancer.

Genetic heterogeneity is high in breast cancer, and hence it is difficult to link a specific chromosome alteration to a specific clinicopathologic feature. We examined clonal chromosome alterations in 45 breast carcinomas and statistically correlated the findings with clinical-histopathological parameters of the patients. The most common abnormalities were losses of chromosomes 19, 22, 21, X, and 17 and gains of chromosomes 9 and 18. A statistically significant correlation was found between clonal aberrations in chromosomes 17, 20, and 21 and positive lymph node involvement (LN+) and between clonal aberrations in chromosomes X and 6 and negative involvement (LN-). The average number of chromosome abnormalities was the same for both LN- and LN+ groups, and numerical and structural alterations were equally distributed. The mean number of chromosome aberrations did not differ significantly among tumor grades, but when aberrations were analyzed as monosomies, trisomies, and structural aberrations, a heterogeneous distribution was observed. Further cytogenetic investigation of breast tumors and their variable pathological features is undoubtedly necessary. The recognition and ultimately the molecular understanding of these abnormalities may improve breast cancer taxonomy and provide important prognostic information for both the patient and clinician.