New Staphylinidae (Coleoptera) records with new collection data from New Brunswick, Canada: Pselaphinae

Twenty species of Pselaphinae are newly recorded from New Brunswick, Canada. This brings the total number of species known from the province to 36. Thirteen of these species are newly recorded for the Maritime provinces of Canada. Dalmosella tenuis Casey and Brachygluta luniger (LeConte) are newly recorded for Canada. Collection and habitat data are presented for these species.     

Patterns and Polarity in Floral Meristem and Floral Organ Initiation

The initial event in plant floral organogenesis is bract specification, followed by floral meristem (FM) initiation in bract axils, but initiation signals and the interplay between both lateral organs remain unelucidated. Floral organs are initiated on the flanks of the outgrowing FM and the enormous diversity in floral morphology throughout the plant kingdom reflects variations in organ position, meristy and ontogeny. Classical models of floral development have focused on Arabidopsis, which has mostly actinomorphic flowers, and Antirrhinum, which exhibits zygomorphy, although neither species is typical or representative of angiosperm flower diversity. Although the ABCE model defines a centripetal model of organ identity establishment in different whorls, the characterization of floral organ initiation in many species has relied on their morphological appearance, due to a lack of founder cell-specific markers. Recent progress in early Arabidopsis floral development using histology, molecular markers and mutants has led to refinements of existing floral organ initiation paradigms. In Arabidopsis, sepals initiate unidirectionally, in a temporal window characterized by the absence of CLAVATA3 and WUSCHEL stem cell markers and are partly dependent on PRESSED FLOWER function, whereas initiation of inner-whorl organs occurs centripetally. Arabidopsis mutants reveal that the FM is highly polarized along an ab-/adaxial axis and a comparison of floral development in Arabidopsis and Antirrhinum suggests that heterochrony of conserved gene functions has been evolutionarily adaptive.

This review discusses current views on FM and organ specification signals, the gene regulatory networks that underlie floral meristem polarity, and analogies between the development of floral and leaf primordia as lateral organs. Alternative stem-cell proliferation mechanisms and the bifurcation of founder cell populations can help to explain the diversity in floral diversity throughout the plant kingdom and underpin comparative evolutionary biology and macroevolution. An analysis of plants with divergent body plans at the level of organ specification is urgently needed.     

Moderate severity heart failure does not involve a downregulation of myocardial fatty acid oxidation

Recent human and animal studies have demonstrated that in severe end-stage heart failure (HF), the cardiac muscle switches to a more fetal metabolic phenotype, characterized by downregulation of free fatty acid (FFA) oxidation and an enhancement of glucose oxidation. The goal of this study was to examine myocardial substrate metabolism in a model of moderate coronary microembolization-induced HF. We hypothesized that during well-compensated HF, FFA oxidation would predominate as opposed to a more fetal metabolic phenotype of greater glucose oxidation. Cardiac substrate uptake and oxidation were measured in normal dogs (n = 8) and in dogs with microembolization-induced HF (n = 18, ejection fraction = 28%) by infusing three isotopic tracers ([9,10-(3)H]oleate, [U-(14)C]glucose, and [1-(13)C]lactate) in anesthetized open-chest animals. There were no differences in myocardial substrate metabolism between the two groups. The total activity of pyruvate dehydrogenase, the key enzyme regulating myocardial pyruvate oxidation (and hence glucose and lactate oxidation) was not affected by HF. We did not observe any difference in the activity of carnitine palmitoyl transferase I (CPT-I) and its sensitivity to inhibition by malonyl-CoA between groups; however, malonyl-CoA content was decreased by 22% with HF, suggesting less in vivo inhibition of CPT-I activity. The differences in malonyl-CoA content cannot be explained by changes in the Michaelis-Menten constant and maximal velocity for malonyl-CoA decarboxylase because neither were affected by HF. These results support the concept that there is no decrease in fatty acid oxidation during compensated HF and that the downregulation of fatty acid oxidation enzymes and the switch to carbohydrate oxidation observed in end-stage HF is only a late-stage phenomenon.     

Replication of pSC101: effects of mutations in the E. coli DNA binding protein IHF

Summary We have shown that the plasmid pSC101 is unable to be maintained in strains of E. coli carrying deletions in the genes himA and hip which specify the pleitropic heterodimeric DNA binding protein, IHF. We show that this effect is not due to a modulation of the expression of the pSC101 RepA protein, required for replication of the plasmid. Inspection of the DNA sequence of the essential replication region of pSC101 reveals the presence of a site, located between the DnaA binding-site and that of RepA, which shows extensive homology with the consensus IHF binding site. The proximity of the sites suggests that these three proteins, IHF, DnaA, and RepA may interact in generating a specific DNA structure required for initiation of pSC101 replication.     

Somatic embryogenesis in Eucalyptus globulus

Somatic embryos were obtained from 1% of cotyledon pieces and hypocotyls of mature embryos of Eucalyptus globulus Labill. cultured on media containing a high concentration of picloram or IBA. 2,4-D and other synthetic auxins did not yield somatic embryos or embryogenic callus. Somatic embryos arose indirectly via callus, being visible after four months, and directly, where little callus or adventitious root initiation occurred. Somatic embryos, formed directly from explants, were visible within five weeks. Various structural abnormalities of somatic embryos were observed, especially after induction on media containing picloram. Only two out of fifteen somatic embryos showed hypocotyl and radical elongation, but plantlets did not develop further.     

Assessing SSU rDNA Barcodes in Foraminifera: A Case Study using Bolivina quadrata

The Small Subunit Ribosomal RNA gene (SSU rDNA) is a widely used tool to reconstruct phylogenetic relationships among foraminiferal species. Recently, the highly variable regions of this gene have been proposed as DNA barcodes to identify foraminiferal species. However, the resolution of these barcodes has not been well established, yet. In this study, we evaluate four SSU rDNA hypervariable regions (37/f, 41/f, 43/e, and 45/e) as DNA barcodes to distinguish among species of the genus Bolivina, with particular emphasis on Bolivina quadrata for which ten new sequences ( KY468817 – KY468826 ) were obtained during this study. Our analyses show that a single SSU rDNA hypervariable sequence is insufficient to resolve all Bolivina species and that some regions (37/f and 41/f) are more useful than others (43/e and 45/e) to distinguish among closely related species. In addition, polymorphism analyses reveal a high degree of variability. In the context of barcoding studies, these results emphasize the need to assess the range of intraspecific variability of DNA barcodes prior to their application to identify foraminiferal species in environmental samples; our results also highlight the possibility that a longer SSU rDNA region might be required to distinguish among species belonging to the same taxonomic group (i.e. genus).     

Association of genetic variants rs641153 (CFB), rs2230199 (C3), and rs1410996 (CFH) with age-related macular degeneration in a Brazilian population

This study aimed to investigate the association among genetic variants of the complement pathway CFB R32Q (rs641153), C3 R102G (rs2230199), and CFH (rs1410996) with age-related macular degeneration (AMD) in a sample of the Brazilian population. In a case-control study, 484 AMD patients were classified according to the clinical age-related maculopathy grading system (CARMS) and compared to 479 unrelated controls. The genetic variants rs1410996 of complement H (CFH), rs641153 of complement factor B (CFB), and rs2230199 of complement 3 (C3) were evaluated through polymerase chain reaction (PCR) and direct sequencing. The associations between single nucleotide polymorphisms (SNPs) and AMD, adjusted by age, were assessed by using logistic regression models. A statistically significant association was observed between AMD risk and rs2230199 variant with an OR of 2.01 (P  = 0.0002) for CG individuals compared to CC individuals. Regarding the comparison of advanced AMD versus the control group, the OR was 2.12 (P = 0.0036) for GG versus AA genotypes for rs1410996 variant. Similarly, the OR for rs2230199 polymorphism was 2.3034 (P  = 5.47^e-05) when comparing CG individuals to CC carriers. In contrast, the rs641153 variant showed a significant protective effect against advanced AMD for GA versus GG genotype (OR = 0.4406; P  = 0.0019). When comparing wet AMD versus controls, a significant association was detected for rs1410996 variant (OR = 2.16; P  = 0.0039) comparing carriers of the homozygous GG versus AA genotype, as well as in the comparisons of GG (OR = 3.0713; P  = 0.0046) and CG genotypes (OR = 2.2249; P  = 0.0002) versus CC genotype for rs2230199 variant, respectively. The rs641153 variant granted a significant protective effect against wet AMD for GA versus GG genotypes (OR = 0.4601; P  = 0.0044). Our study confirmed the risk association between rs2230199 and rs1410996 variants and AMD, and the protective role against AMD for rs641153 variant.