RECENT ORNITHOLOGICAL PUBLICATIONS

The status of the Common Moorhen Gallinula chloropus in Algeria and its breeding ecology in North Africa are reported for the first time. Nest site selection and breeding parameters were studied at two contrasting sites in north-east Algeria: Boussedra, an unprotected freshwater marsh of 55 ha subject to anthropogenic influence, during 2005 and 2008, and Lake Tonga, a protected freshwater marsh of 2 400 ha in 2009. Most nests (92%) at Boussedra were located in dense stands of lesser bulrush Typha angustifolia, whereas a few were found on lower branches of tamarisk Tamarix gallica trees. In contrast, at Lake Tonga nests were predominantly found on Scirpus lacustris (41%) or associated with alder trees Alnus glutinosa (32%). Egg-laying at both sites occurred between early April and the end of June. There was a significant decrease in egg volume as the breeding season progressed. Mean clutch size at Lake Tonga (7.8 ± 2.9, N = 23 clutches) did not differ significantly from that at Boussedra (6.7 ± 2.1, N = 14 clutches). Similarly, hatching success (67–72%) and predation rate of nests with eggs (16–28%) did not vary significantly between sites. The Common Moorhen may be more resilient than marsh specialists to anthropogenic changes.     

Toll Like Receptor 3 Plays a Critical Role in the Progression and Severity of Acetaminophen-Induced Hepatotoxicity

Toll-like receptor (TLR) activation has been implicated in acetaminophen (APAP)-induced hepatotoxicity. Herein, we hypothesize that TLR3 activation significantly contributed to APAP-induced liver injury. In fasted wildtype (WT) mice, APAP caused significant cellular necrosis, edema, and inflammation in the liver, and the de novo expression and activation of TLR3 was found to be necessary for APAP-induced liver failure. Specifically, liver tissues from similarly fasted TLR3-deficient (tlr3^−/−) mice exhibited significantly less histological and biochemical evidence of injury after APAP challenge. Similar protective effects were observed in WT mice in which TLR3 was targeted through immunoneutralization at 3 h post-APAP challenge. Among three important death ligands (i.e. TNFα, TRAIL, and FASL) known to promote hepatocyte death after APAP challenge, TNFα was the only ligand that was significantly reduced in APAP-challenged tlr3^−/− mice compared with APAP-challenged WT controls. In vivo studies demonstrated that TLR3 activation contributed to TNFα production in the liver presumably via F4/80⁺ and CD11c⁺ immune cells. In vitro studies indicated that there was cooperation between TNFα and TLR3 in the activation of JNK signaling in isolated and cultured liver epithelial cells (i.e. nMuLi). Moreover, TLR3 activation enhanced the expression of phosphorylated JNK in APAP injured livers. Thus, the current study demonstrates that TLR3 activation contributes to APAP-induced hepatotoxicity.     

Ecological studies on the Lime Hill serpentine,Scotland

Summary

Lime Hill is an example of a serpentine outcrop which shows only to a limited extent the features of vegetation often associated with ultrabasic rock. Plant and soil analyses from this site are presented and compared with those from other Scottish serpentines. Substantial quantities of heavy metals are present at Lime Hill. It is suggested that the cause of the absence of serpentine-characteristic plants lies in a relatively low soil Mg : Ca ratio and/or high P and K levels.     

Cophylogenetic assessment of New World warblers (Parulidae) and their symbiotic feather mites (Proctophyllodidae)

Host–symbiont relationships are ubiquitous in nature, yet evolutionary and ecological processes that shape these intricate associations are often poorly understood. All orders of birds engage in symbioses with feather mites, which are ectosymbiotic arthropods that spend their entire life on hosts. Due to their permanent obligatory association with hosts, limited dispersal and primarily vertical transmission, we hypothesized that the cospeciation between feather mites and hosts within one avian family (Parulidae) would be perfect (strict cospeciation). We assessed cophylogenetic patterns and tested for congruence between species in two confamiliar feather mite genera (Proctophyllodidae: Proctophyllodes, Amerodectes) found on 13 species of migratory warblers (and one other closely related migratory species) in the eastern United States. Based on COI sequence data, we found three Proctophyllodes lineages and six Amerodectes lineages. Distance‐ and event‐based cophylogenetic analyses suggested different cophylogenetic trajectories of the two mite genera, and although some associations were significant, there was little overall evidence supporting strict cospeciation. Host switching is likely responsible for incongruent phylogenies. In one case, we documented prairie warblers Setophaga discolor harboring two mite species of the same genus. Most interestingly, we found strong evidence that host ecology may influence the likelihood of host switching occurring. For example, we documented relatively distantly related ground‐nesting hosts (ovenbird Seiurus aurocapilla and Kentucky warbler Geothlypis formosa) sharing a single mite species, while other birds are shrub/canopy or cavity nesters. Overall, our results suggest that cospeciation is not the case for feather mites and parulid hosts at this fine phylogenetic scale, and raise the question if cospeciation applies for other symbiotic systems involving hosts that have complex life histories. We also provide preliminary evidence that incorporating host ecological traits into cophylogenetic analyses may be useful for understanding how symbiotic systems have evolved.     

Cyanoseq: A database of cyanobacterial 16S rRNA gene sequences with curated taxonomy

Cyanobacteria are photosynthetic bacteria that occupy various habitats across the globe, playing critical roles in many of Earth's biogeochemical cycles both in both aquatic and terrestrial systems. Despite their well-known significance, their taxonomy remains problematic and is the subject of much research. Taxonomic issues of Cyanobacteria have consequently led to inaccurate curation within known reference databases, ultimately leading to problematic taxonomic assignment during diversity studies. Recent advances in sequencing technologies have increased our ability to characterize and understand microbial communities, leading to the generation of thousands of sequences that require taxonomic assignment. We herein propose CyanoSeq ( https://zenodo.org/record/7569105 ), a database of cyanobacterial 16S rRNA gene sequences with curated taxonomy. The taxonomy of CyanoSeq is based on the current state of cyanobacterial taxonomy, with ranks from the domain to genus level. Files are provided for use with common naive Bayes taxonomic classifiers, such as those included in DADA2 or the QIIME2 platform. Additionally, FASTA files are provided for creation of de novo phylogenetic trees with (near) full-length 16S rRNA gene sequences to determine the phylogenetic relationship of cyanobacterial strains and/or ASV/OTUs. The database currently consists of 5410 cyanobacterial 16S rRNA gene sequences along with 123 Chloroplast, Bacterial, and Vampirovibrionia (formally Melainabacteria) sequences.     

Activation of cell stress response pathways by Shiga toxins

Shiga toxin-producing bacteria cause widespread outbreaks of bloody diarrhoea that may progress to life-threatening systemic complications. Shiga toxins (Stxs), the main virulence factors expressed by the pathogens, are ribosome-inactivating proteins which inhibit protein synthesis by removing an adenine residue from 28S rRNA. Recently, Stxs were shown to activate multiple stress-associated signalling pathways in mammalian cells. The ribotoxic stress response is activated following the depurination reaction localized to the α-sarcin/ricin loop of eukaryotic ribosomes. The unfolded protein response (UPR) may be initiated by toxin unfolding within the endoplasmic reticulum, and maintained by production of truncated, misfolded proteins following intoxication. Activation of the ribotoxic stress response leads to signalling through MAPK cascades, which appears to be critical for activation of innate immunity and regulation of apoptosis. Precise mechanisms linking ribosomal damage with MAPK activation require clarification but may involve recognition of ribosomal conformational changes and binding of protein kinases to ribosomes, which activate MAP3Ks and MAP2Ks. Stxs appear capable of activating all ER membrane localized UPR sensors. Prolonged signalling through the UPR induces apoptosis in some cell types. The characterization of stress responses activated by Stxs may identify targets for the development of interventional therapies to block cell damage and disease progression.     

Genomic and proteomic analysis of invertebrate iridovirus type 9

Iridoviruses (IV) are nuclear cytoplasmic large DNA viruses that are receiving increasing attention as sublethal pathogens of a range of insects. Invertebrate iridovirus type 9 (IIV-9; Wiseana iridovirus) is a member of the major phylogenetic group of iridoviruses for which there is very limited genomic and proteomic information. The genome is 205,791 bp, has a G+C content of 31%, and contains 191 predicted genes, with approximately 20% of its repeat sequences being located predominantly within coding regions. The repeated sequences include 11 proteins with helix-turn-helix motifs and genes encoding related tandem repeat amino acid sequences. Of the 191 proteins encoded by IIV-9, 108 are most closely related to orthologs in IIV-3 (Chloriridovirus genus), and 114 of the 126 IIV-3 genes have orthologs in IIV-9. In contrast, only 97 of 211 IIV-6 genes have orthologs in IIV-9. There is almost no conservation of gene order between IIV-3, IIV-6, and IIV-9. Phylogenetic analysis using a concatenated sequence of 26 core IV genes confirms that IIV-3 is more closely related to IIV-9 than to IIV-6, despite being from a different genus of the Iridoviridae. An interaction between IIV and small RNA regulatory systems is supported by the prediction of seven putative microRNA (miRNA) sequences combined with XRN exonuclease, RNase III, and double-stranded RNA binding activities encoded on the genome. Proteomic analysis of IIV-9 identified 64 proteins in the virus particle and, when combined with infected cell analysis, confirmed the expression of 94 viral proteins. This study provides the first full-genome and consequent proteomic analysis of group II IIV.