Annual phytoplankton cycle in a meromictic anoxic basin of a Rhode Island (USA) estuarine river

Hydrobiologia - Estuarine Pettaquamscutt River is a unique habitat 10 km in length with physical and biogeochemical characteristics analogous to a miniature fjord. Its meromictic upper...     

Non-linear dielectric spectroscopy of microbiological suspensions

Background  

Non-linear dielectric spectroscopy (NLDS) of microorganism was characterized by the generation of harmonics in the polarization current when a microorganism suspension was exposed to a sinusoidal electric field. The biological nonlinear response initially described was not well verified by other authors and the results were susceptible to ambiguous interpretation. In this paper NLDS was performed to yeast suspension in tripolar and tetrapolar configuration with a recently developed analyzer.     

Evidence of Heavy Methylation in the Galectin 3 Promoter in Early Stages of Prostate Adenocarcinoma: Development and Validation of a Methylated Marker for Early Diagnosis of Prostate Cancer

Galectins, soluble intracellular and extracellular β-galactoside-binding proteins, are known to be involved in the progression and metastasis of various cancers, including prostate adenocarcinoma, but the detailed mechanism of their biological roles remains elusive. In the prostate cancer cell lines PC-3 and DU-145, galectin 3 (gal3) is present at normal levels, whereas in LNCaP, its expression is silenced. In LNCaP, the gal3 promoter was heavily methylated, whereas PC-3 or DU-145 cells showed negligible or no methylation in the gal3 promoter indicating a negative correlation between gal3 promoter methylation and its expression. On immunohistochemical analysis of normal and tumor prostate tissues, gal3 was found expressed both in nucleus and cytoplasm of benign prostatic hyperplasia, high-grade prostatic intraepithelial neoplasia, and stage I. The expression of the gal3 was found drastically downregulated in advanced stages and, interestingly, mostly in the cytoplasm. On methylation analysis, the gal3 promoter in stage II prostate adenocarcinoma (PCa) was found heavily methylated, whereas in stages III and IV, it was only lightly methylated. However, in stage I PCa, both heavy and light methylations were observed in the gal3 promoter. In normal and benign prostatic hyperplasia tissues, the gal3 promoter was almost unmethylated. The differential cytosine methylation in the gal3 promoter in stages I to IV PCa enabled us to develop and validate a methylation-specific polymerase chain reaction-based sensitive assay specific for stages I and II PCa. These stages are considered the critical stages for successful intervention, thus underscoring the significance of this diagnostic assay.     

Does divergence from normal patterns of integration increase as chromosomal fusions increase in number? A test on a house mouse hybrid zone

Chromosomal evolution is widely considered an important driver of speciation because it can promote the establishment of reproductive barriers. Karyotypic reorganization is also expected to affect the mean phenotype, as well as its development and patterns of phenotypic integration, through processes such as variation in genetic linkage between quantitative trait loci or between regulatory regions and their targets. Here we explore the relationship between chromosomal evolution and phenotypic integration by analyzing a well-known house mouse parapatric contact zone between a highly derived Robertsonian (Rb) race (2n = 22) and populations with standard karyotype (2n = 40). Populations with hybrid karyotypes are scattered throughout the hybrid zone connecting the two parental races. Using mandible shape data and geometric morphometrics, we test the hypothesis that patterns of integration progressively diverge from the “normal” integration pattern observed in the standard race as they accumulate Rb fusions. We find that the main pattern of integration observed between the posterior and anterior part of the mandible can be largely attributed to allometry. We find no support for a gradual increase in divergence from normal patterns of integration as fusions accumulate. Surprisingly, however, we find that the derived Rb race (2n = 22) has a distinct allometric trajectory compared with the standard race. Our results suggest that either individual fusions disproportionately affect patterns of integration or that there are mechanisms which “purge” extreme variants in hybrids (e.g. reduced fitness of hybrid shape).     

Congruence between cytochrome oxidase I (COI) and morphological data in Anuraphis spp. (Hemiptera,Aphididae) with a comparison between the utility of the 5’ barcode and 3’ COI regions

The discrimination of species in the genus Anuraphis is particularly difficult due to the overlap of morphological characters. In this study, we used the 5’ (barcode) and 3’ regions of cytochrome oxidase I (COI) to test their utility in the identification of species in this genus as well as closely related species. Both regions were useful to discriminate all the species tested. However the non-barcode 3’ region resulted in higher resolution and support for species relationships when the data were analyzed using both Maximum Likelihood and MrBayes. We propose the development of an integrated database that encompasses morphological, molecular, life-cycle, host plant and bibliographic information to facilitate and increase the accuracy of aphid identification.