Characterising the interspecific variations and convergence of gut microbiota in Anseriformes herbivores at wintering areas

AbstractMicroorganisms in vertebrate guts have been recognized as important symbionts influencing host life. However, it remains unclear about the gut microbiota in long-distance migratory Anseriformes herbivores, which could be functionally important for these wetland-dependent animals. We collected faeces of the greater white-fronted goose (GWFG), bean goose (BG) and swan goose (SG) from Shengjin Lake (SJL) and Poyang Lake (PYL) in the Yangtze River Floodplain, China. High-throughput sequencing of 16S rRNA V4 region was employed to depict the composition and structure of geese gut microbiota during wintering period. The dominant bacterial phyla across all samples were Firmicutes, Proteobacteria and Actinobacteria, but significant variations were detected among different goose species and sampling sites, in terms of α diversity, community structures and microbial interactions. We found a significant correlation between diet and the microbial community structure in GWFG-SJL samples. These results demonstrated that host species and diet are potential drivers of goose gut microbiota assemblies. Despite these variations, functions of geese gut microbiota were similar, with great abundances of potential genes involved in nutrient metabolism. This preliminary study would be valuable for future, exhaustive investigations of geese gut microbiota and their interactions with host.</jats:p

&lt;strong&gt;&lt;em&gt;Stagonosporopsis rhizophilae sp. nov.&lt;/em&gt; (Didymellaceae, Pleosporales), a new rhizospheric soil fungus associated with &lt;em&gt;Populus deltoides&lt;/em&gt; Marsh&lt;/strong&gt;

In this work we describe Stagonosporopsis rhizophilae sp. nov. (Didymellaceae, Pleosporales, Ascomycota), a new species isolated from the rhizospheric soil of Populus deltoides Marsh. Phylogenetic analyses based on combined multilocus sequences of internal transcribed spacers (ITS: ITS1, 5.8S, ITS2), and partial sequences of the large subunit 28S nrDNA region (LSU), β-tubulin (TUB), and RNA Polymerase II second-largest subunit (RPB2) clearly place this species within the genus Stagonosporopsis but distinguishes it from all known and closely related species such as S. nemophilae. Stagonosporopsis rhizophilae sp. nov. can also be differentiated from S. nemophilae by morphological characters and by the negative response of the NaOH spot test for the production of metabolite E.</jats:p

Selection of a marker gene to construct a reference library for wetland plants, and the application of metabarcoding to analyze the diet of wintering herbivorous waterbirds

Food availability and diet selection are important factors influencing the abundance and distribution of wild waterbirds. In order to better understand changes in waterbird population, it is essential to figure out what they feed on. However, analyzing their diet could be difficult and inefficient using traditional methods such as microhistologic observation. Here, we addressed this gap of knowledge by investigating the diet of greater white-fronted goose Anser albifrons and bean goose Anser fabalis, which are obligate herbivores wintering in China, mostly in the Middle and Lower Yangtze River floodplain. First, we selected a suitable and high-resolution marker gene for wetland plants that these geese would consume during the wintering period. Eight candidate genes were included: rbcL, rpoC1, rpoB, matK, trnH-psbA, trnL (UAA), atpF-atpH, and psbK-psbI. The selection was performed via analysis of representative sequences from NCBI and comparison of amplification efficiency and resolution power of plant samples collected from the wintering area. The trnL gene was chosen at last with c/h primers, and a local plant reference library was constructed with this gene. Then, utilizing DNA metabarcoding, we discovered 15 food items in total from the feces of these birds. Of the 15 unique dietary sequences, 10 could be identified at specie level. As for greater white-fronted goose, 73% of sequences belonged to Poaceae spp., and 26% belonged to Carex spp. In contrast, almost all sequences of bean goose belonged to Carex spp. (99%). Using the same samples, microhistology provided consistent food composition with metabarcoding results for greater white-fronted goose, while 13% of Poaceae was recovered for bean goose. In addition, two other taxa were discovered only through microhistologic analysis. Although most of the identified taxa matched relatively well between the two methods, DNA metabarcoding gave taxonomically more detailed information. Discrepancies were likely due to biased PCR amplification in metabarcoding, low discriminating power of current marker genes for monocots, and biases in microhistologic analysis. The diet differences between two geese species might indicate deeper ecological significance beyond the scope of this study. We concluded that DNA metabarcoding provides new perspectives for studies of herbivorous waterbird diets and inter-specific interactions, as well as new possibilities to investigate interactions between herbivores and plants. In addition, microhistologic analysis should be used together with metabarcoding methods to integrate this information

Data collected in an integrated ecological survey of rotifer communities and corresponding environmental variables in the highly polluted Haihe River Basin, China

Here we presented two datasets (biological and environmental datasets) collected in a comprehensive large geographical scale (approximately 1.1×105 km2) survey of rivers/streams in the Haihe River Basin (HRB), which has become the most polluted river basin in past two decades in China. The survey selected a total of 94 representative sampling sites in the plain region of HRB, where environmental pollution is more severe than the mountain region. The biological dataset contains the information on the identified rotifer species and their abundance, while the environmental dataset provides the measured environmental variables at each sampling site. Based on this ecological survey, we identified a total of 91 rotifer species and their abundance, as well as abundance of two crucial taxonomic groups on rotifers’ food webs (i.e., protozoans and crustaceans), and also presented seven environmental variables, particularly those associated with nitrogen and phosphorus pollution. Keywords: Environmental pollution, Nitrogen, Phosphorus, Rotifer, Strea