Pathogens,faecal indicators and human-specific microbial source-tracking markers in sewage

The objective of this review is to assess the current state of knowledge of pathogens, general faecal indicators and human-specific microbial source tracking markers in sewage. Most of the microbes present in sewage are from the microbiota of the human gut, including pathogens. Bacteria and viruses are the most abundant groups of microbes in the human gut microbiota. Most reports on this topic show that raw sewage microbiological profiles reflect the human gut microbiota. Human and animal faeces share many commensal microbes as well as pathogens. Faecal-orally transmitted pathogens constitute a serious public health problem that can be minimized through sanitation. Assessing both the sanitation processes and the contribution of sewage to the faecal contamination of water bodies requires knowledge of the content of pathogens in sewage, microbes indicating general faecal contamination and microbes that are only present in human faecal remains, which are known as the human-specific microbial source-tracking (MST) markers. Detection of pathogens would be the ideal option for managing sanitation and determining the microbiological quality of waters contaminated by sewage; but at present, this is neither practical nor feasible in routine testing. Traditionally, faecal indicator bacteria have been used as surrogate indicators of general faecal residues. However, in many water management circumstances, it becomes necessary to detect both the origin of faecal contamination, for which MST is paramount, and live micro-organisms, for which molecular methods are not suitable. The presence and concentrations of pathogens, general faecal indicators and human-specific MST markers most frequently reported in different areas of the world are summarized in this review.     

Fischerella thermalis: a model organism to study thermophilic diazotrophy,photosynthesis and multicellularity in cyanobacteria

Extremophiles - The true-branching cyanobacterium Fischerella thermalis (also known as Mastigocladus laminosus) is widely distributed in hot springs around the world. Morphologically, it has been...     

Divergence with gene flow is driven by local adaptation to temperature and soil phosphorus concentration in teosinte subspecies (Zea mays parviglumis and Zea mays mexicana)

Patterns of genomic divergence between hybridizing taxa can be heterogeneous along the genome. Both differential introgression and local adaptation may contribute to this pattern. Here, we analysed two teosinte subspecies, Zea mays ssp. parviglumis and ssp. mexicana, to test whether their divergence has occurred in the face of gene flow and to infer which environmental variables have been important drivers of their ecological differentiation. We generated 9,780 DArTseqTM SNPs for 47 populations, and used an additional data set containing 33,454 MaizeSNP50 SNPs for 49 populations. With these data, we inferred features of demographic history and performed genome wide scans to determine the number of outlier SNPs associated with climate and soil variables. The two data sets indicate that divergence has occurred or been maintained despite continuous gene flow and/or secondary contact. Most of the significant SNP associations were to temperature and to phosphorus concentration in the soil. A large proportion of these candidate SNPs were located in regions of high differentiation that had been identified previously as putative inversions. We therefore propose that genomic differentiation in teosintes has occurred by a process of adaptive divergence, with putative inversions contributing to reduced gene flow between locally adapted populations.     

A global review and meta-analysis of applications of the freshwater Fish Invasiveness Screening Kit

Reviews in Fish Biology and Fisheries - The freshwater Fish Invasiveness Screening Kit (FISK) has been applied in 35 risk assessment areas in 45 countries across the six inhabited continents (11...     

Intrinsic competition between resident and invasive parasitoids (Hymenoptera: Braconidae) that attack the West Indian fruit fly Anastrepha obliqua under field conditions

We evaluated under semi-field conditions the intrinsic competition between Diachasmimorpha longicaudata (Ashmead), as an invasive parasitoid, and Doryctobracon areolatus (Szépligeti) and Utetes anastrephae (Viereck) (all Hymenoptera: Braconidae) as resident parasitoids, as well as that between U. anastrephae as an invader and D. areolatus as a resident. The percentage of live D. areolatus larvae decreased by 39.8% and 29.4% following attack by D. longicaudata and U. anastrephae as invasive parasitoids, respectively. Likewise, the parasitism percentage of D. areolatus decreased by 31.5% and 60.8% under competition with the invasive parasitoids D. longicaudata and U. anastrephae, respectively. Parasitism by D. longicaudata decreased by 44.6% and 41.6% in the presence of the residents D. areolatus and U. anastrephae, respectively, while parasitism of U. anastrephae was only affected when this species was a resident. We concluded that D. areolatus is an inferior intrinsic competitor and that U. anastrephae resists the competitive presence of D. longicaudata.     

CONSTANS delays Arabidopsis flowering under short days

Long days (LD) promote flowering of Arabidopsis thaliana compared with short days (SD) by activating the photoperiodic pathway. Here we show that growth under very‐SD (3 h) or darkness (on sucrose) also accelerates flowering on a biological scale, indicating that SD actively repress flowering compared with very‐SD. CONSTANS (CO) repressed flowering under SD, and the early flowering of co under SD required FLOWERING LOCUS T (FT). FT was expressed at a basal level in the leaves under SD, but these levels were not enhanced in co. This indicates that the action of CO in A. thaliana is not the mirror image of the action of its homologue in rice. In the apex, CO enhanced the expression of TERMINAL FLOWER 1 (TFL1) around the time when FT expression is important to promote flowering. Under SD, the tfl1 mutation was epistatic to co and in turn ft was epistatic to tfl1. These observations are consistent with the long‐standing but not demonstrated model where CO can inhibit FT induction of flowering by affecting TFL1 expression.