Pseudomonas petrae sp. nov. isolated from regolith samples in Antarctica

A polyphasic taxonomic approach was used to characterize the four strains P2653^T, P2652, P2498, and P2647, isolated from Antarctic regolith samples. Initial genotype screening performed by PCR fingerprinting based on repetitive sequences showed that the isolates studied formed a coherent cluster separated from the other Pseudomonas species. Identification results based on 16S rRNA gene sequences showed the highest sequence similarity with Pseudomonas graminis (99.7%), which was confirmed by multilocus sequence analysis using the rpoB, rpoD, and gyrB genes. Genome sequence comparison of P2653^T with the most related P. graminis type strain DSM 11363^T revealed an average nucleotide identity of 92.1% and a digital DNA-DNA hybridization value of 46.6%. The major fatty acids for all Antarctic strains were C_16:0, Summed Feature 3 (C_16:1 ω7c/C_16:1 ω6c) and Summed Feature 8 (C_18:1 ω7c/C_18:1 ω6c). The predominant respiratory quinone was Q-9, and the major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylglycerol. The regolith strains could be differentiated from related species by the absence of arginine dihydrolase, ornithine and lysine decarboxylase and by negative tyrosine hydrolysis. The results of this polyphasic study allowed the genotypic and phenotypic differentiation of four analysed strains from the closest related species, which confirmed that the strains represent a novel species within the genus Pseudomonas, for which the name Pseudomonas petrae sp. nov. is proposed with P2653^T (CCM 8850^T = DSM 112068^T = LMG 30619^T) as the type strain.     

Early stages and the classification of the milkweed butterflies (Lepidoptera: Danainae)

The Danainae, or milkweed butterflies, are a moderate-sized group of around 150 species that are of considerable ecological, physiological and behavioural interest. There are two currently accepted classifications for the subfamily and the aim of this study was to try to resolve this conflict using characters derived from the eggs, larvae and pupae. The 130 new characters (of which 85 are illustrated) are analysed by both phenetic methods (average linkage cluster analysis and principal coordinate analysis) and by cladistic techniques (Wagner tree, character compatibility analysis and manually derived cladograms). Overall, the results corroborate the more recent classification of the Danainae. However, some points of difference are found and, after component analysis, an alternative classification is presented in accordance with the conventions for constructing annotated Linnaean hierarchies.     

Insertion of an intermediate repetitive sequence into a sea urchin histone-gene spacer

Summary A common polymorphism of the early embryonic histone-gene repeat ofStrongylocentrotus purpuratus is a 195-bp insertion within the H4-H2B spacer. The sequence, found as an insert in histone-gene repeats of 6 of 22 individuals screened, is also found at approximately 50 sites elsewhere in the genome of every individual. We compare the sequences of the histone-gene spacers that do and do not contain the insert. The insert is found not to have transposon-like features, and no sequence in the original spacer has been duplicated to flank the insert. There is, however, a hexanucleotide sequence that is repeated three times at one end of the insert, and the element has inserted between direct repeats of 5 bp that were present in the original spacer. One of the copies found outside the histone gene cluster was cloned and sequenced and is compared with the insert. Again, no transposon-like features are evident. Regions flanking the homologous sequence in this clone were used as hybridization probes in whole-genome blots. Results indicate that the 195-bp sequence insert is itself embedded within a larger element that is repeated within the genome. Therefore, only a portion of a larger repetitive sequence has integrated into the histone-gene spacer. The sequence features of the insert, although not typical of mobile elements, may be representative of other illegitimate recombination events.     

Centromere organization and UU/V sex chromosome behavior in a liverwort

In 1917, sex chromosomes in plants were discovered in a liverwort with hetermorphic U and V chromosomes. Such heteromorphy is unexpected because, unlike the XY chromosomes in diploid-dominant plants, in haploid-dominant plants the female U and the male V chromosomes experience largely symmetrical potential recombination environments. Here we use molecular cytogenetics and super-resolution microscopy to study Frullania dilatata, a liverwort with one male and two female sex chromosomes. We applied a pipeline to Illumina sequences to detect abundant types of repetitive DNA and developed FISH probes to microscopically distinguish the sex chromosomes. We also determined the phenotypic population sex ratio because biased ratios have been reported from other liverworts with heteromorphic sex chromosomes. Populations had male-biased sex ratios. The sex chromosomes are monocentric, and of 14 probes studied (eight satellites, five transposable elements and one plastid region), four resulted in unique signals that differentiated the sex chromosomes from the autosomes and from each other. One FISH probe selectively marked the centromeres of both U chromosomes, so we could prove that during meiosis each U chromosome associates with one of the opposite telomeres of the V chromosome, resulting in a head-to-head trivalent. The similarity of the two U chromosomes to each other in size and in their centromere FISH signal positions points to their origin via a non-disjunction event (aneuploidy), which would fit with the general picture of sex chromosomes rarely crossing-over and being prone to suffer from non-disjunction.     

Selection of Contaminants and Receptors of Concern for Ecological Risk Assessments Using the Paired Comparison Technique (PCT)

A critical component of the ecological risk assessment process, identification of contaminants and receptors of concern, is currently lacking an objective, data-driven, broadly applicable methodology. The paired comparison technique (PCT) can be used to meet this need by providing a standardized technique for making these decisions. PCT condenses the decision-making process down to individual components and ultimately generates an objective ranking for each alternative based on pertinent attributes. Factors considered in the PCT may be selected and weighted via a formal consensus building process which can incorporate stakeholder concerns. Once factors have been selected and weighted, each alternative is ranked relative to each other alter native for each factor. Each alternative ranking for each factor is multiplied by the factor's weight and the weighted rankings are summed. These sums are then used to rank alternatives relative to one another. This ranking provides decision-makers with a semi quantitative basis for making final decisions, although the technique itself does not (and should not) actually make the decision. Several examples of the technique using actual Superfund site data are presented.     

高压氧联合高频rTMS对重型颅脑损伤后意识障碍患者促醒作用、神经电生理和脑损伤标志物的影响

摘要 目的：探讨高压氧联合高频重复经颅磁刺激（rTMS）对重型颅脑损伤后意识障碍（DOC）患者促醒作用、神经电生理和脑损伤标志物的影响。方法：选取2021年6月~2023年6月期间安徽中医药大学附属六安医院收治的的80例重型颅脑损伤后DOC患者。根据随机数字表法分为对照组（n=40,高压氧治疗）和观察组（n=40,高压氧联合高频rTMS治疗）。对比两组疗效、促醒作用、神经电生理和脑损伤标志物水平变化情况。结果：观察组的临床总有效率高于对照组（P<0.05）。两组治疗4周后修订的昏迷恢复量表（CRS-R）、格拉斯哥昏迷量表（GCS）评分升高,观察组高于对照组（P<0.05）。两组治疗4周后脑干听觉诱发电位（BAFP）、四肢体感诱发电位（SEP）、脑电图（EEG）分级有所改善,观察组改善效果优于对照组（P<0.05）。两组治疗4周后髓鞘碱蛋白（MBP）、神经元特异性烯醇化酶（NSE）、S100β蛋白下降,观察组低于对照组（P<0.05）。结论：高压氧联合高频rTMS治疗可有效促醒重型颅脑损伤后DOC患者,还可改善神经电生理活动,减轻脑损伤程度。     

Second German-Catalan workshop on epigenetics & cancer

The Second German-Catalan Workshop on Epigenetics and Cancer was held in Barcelona on November 19–21, 2014. The workshop brought together, for the second time, scientists from 2 German and 2 Catalan research institutions: the DKFZ, from Heidelberg, the CRCME, from Freiburg, and the IMPPC and PEBC/IDIBELL, both from Barcelona. The German-Catalan Workshops are intended to establish the framework for building a Research School to foster collaborations between researchers from the different institutions. Exchange programs for graduate students are among the activities of the future School. The topics presented and discussed in 33 talks were diverse and included work on DNA methylation, histone modifications, chromatin biology, characterization of imprinted regions in human tissues, non-coding RNAs, and epigenetic drug discovery. Among novel developments from the previous Workshop are the report of the epigenetics angle of the Warburg effect and the long-range trans-acting interaction of DNA methylation and of nucleosome remodeling. A shift in the view on DNA methylation became apparent by the realization of the intertwined interplay between hyper- and hypo-methylation in differentiation and cancer.     

Chromosomal rearrangements and the first indication of an ♀X1X1X2X2/♂X1X2Y sex chromosome system in Rineloricaria fishes (Teleostei: Siluriformes)

Rineloricaria is the most diverse genus within the freshwater fish subfamily Loricariinae, and it is widely distributed in the Neotropical region. Despite limited cytogenetic data, records from southern and south-eastern Brazil suggest a high rate of chromosomal rearrangements in this genus, mirrored in remarkable inter- and intraspecific karyotype variability. In the present work, we investigated the karyotype features of Rineloricaria teffeana, an endemic representative from northern Brazil, using both conventional and molecular cytogenetic techniques. We revealed different diploid chromosome numbers (2n) between sexes (33♂/34♀), which suggests the presence of an ♀X₁X₁X₂X₂/♂X₁X₂Y multiple sex chromosome system. The male-limited Y chromosome was the largest and the only biarmed element in the karyotype, implying Y-autosome fusion as the most probable mechanism behind its origination. C-banding revealed low amounts of constitutive heterochromatin, mostly confined to the (peri)centromeric regions of most chromosomes (including the X₂ and the Y) but also occupying the distal regions of a few chromosomal pairs. The chromosomal localization of the 18S ribosomal DNA (rDNA) clusters revealed a single site on chromosome pair 4, which was adjacent to the 5S rDNA cluster. Additional 5S rDNA loci were present on the autosome pair 8, X₁ chromosome, and in the presumed fusion point on the Y chromosome. The probe for telomeric repeat motif (TTAGGG)_n revealed signals of variable intensities at the ends of all chromosomes except for the Y chromosome, where no detectable signals were evidenced. Male-to-female comparative genomic hybridization revealed no sex-specific or sex-biased repetitive DNA accumulations, suggesting a presumably low level of neo-Y chromosome differentiation. We provide evidence that rDNA sites might have played a role in the formation of this putative multiple sex chromosome system and that chromosome fusions originate through different mechanisms among different Rineloricaria species.