Sex predicts gut microbiota variations in wild yellow baboons (Papio cynocephalus)

The role of gut microbiota diversity in animal ecology and conservation has become a key topic, especially since the contribution of these bacterial and fungal communities to host growth and health has been recently recognized. Most investigations in wildlife have focused on the study of extrinsic (e.g., diet, habitat) rather than intrinsic factors (e.g., sex, genetic background) affecting variation in animal gut communities. However, since male and female mammals often differ in biological traits and functional needs, sex is likely to play a major role in gut microbiota variation. Here, we evaluated if and how sex is associated with the gut microbiota richness and composition of wild yellow baboons (Papio cynocephalus) living in two habitat types, protected and unprotected forests of the Udzungwa Mountains in Tanzania. To understand whether sex and habitat type affect gut microbiota variation, we determined the sex of 34 yellow baboons (19 females and 15 males) from fecal pellets collected non-invasively using two marker genes (SRY and DDX3X). We then combined these results with amplicon sequencing datasets focusing on bacterial (V3-V4 region of the 16S rRNA gene) and fungal (ITS1-ITS2) communities of the same pellets. We found that females had gut microbiotas with a higher bacterial richness [Kruskal test; Shannon (alpha diversity): P = 0.010] and different composition [ANOVA; weighted Unifrac (beta diversity): P = 0.030] compared to males, in agreement with the strong morphological and behavioural dimorphisms shown between sexes of this species. Furthermore, forest type had a greater impact on females than males, such that the gut microbiotas of females from the two forests differed significantly in fungal composition [pairwise adonis test; Bray-Curtis: P = 0.02] and bacterial richness [pairwise Wilcoxon Rank Sum test; Shannon: P = 0.023], while those of males did not. These results indicated that the impact of habitat disturbance varied with sex, suggesting that intrinsic biological factors should be carefully considered when investigating wild animal biodiversity at any scale, and that such intraspecific variation could impact the outcome of conservation actions. However, research on the metabolic pathways, through shotgun sequencing, are encouraged to verify whether greater gut bacterial richness, such as those observed in baboon females, may translate into a greater diversity of metabolic functions

Exploring the Gut Microbiome Alteration of the European Hare (Lepus europaeus) after Short-Term Diet Modifications

This study aimed to characterise the gut microbiome composition of European hares (Lepus europaeus) and its potential changes after a short-term diet modification. The high sensitivity of European hare to habitat changes makes this species a good model to analyse possible alterations in gut microbiome after the introduction of additional nourishment into the diet. In total, 20 pairs were chosen for the experiments; 10 pairs formed the control group and were fed with standard fodder. The other 10 pairs represented the experimental group, whose diet was integrated with apples and carrots. The DNA from fresh faecal pellets collected after 4 days from the start of the experiment was extracted and the V3-V4 hypervariable regions were amplified and sequenced using the Illumina MiSeq® platform. The obtained amplicon sequence variants were classified into 735 bacterial genera belonging to 285 families and 36 phyla. The control and the experimental groups appeared to have a homogenous dispersion for the two taxonomic levels analysed with the most abundant phyla represented by Bacteroidetes and Firmicutes. No difference between control and experimental samples was detected, suggesting that the short-term variation in food availability did not alter the hares’ gut microbiome. Further research is needed to estimate significant time threshold

CENP-A binding domains and recombination patterns in horse spermatocytes

Centromeres exert an inhibitory effect on meiotic recombination, but the possible contribution of satellite DNA to this "centromere effect" is under debate. In the horse, satellite DNA is present at all centromeres with the exception of the one from chromosome 11. This organization of centromeres allowed us to investigate the role of satellite DNA on recombination suppression in horse spermatocytes at the stage of pachytene. To this aim we analysed the distribution of the MLH1 protein, marker of recombination foci, relative to CENP-A, marker of centromeric function. We demonstrated that the satellite-less centromere of chromosome 11 causes crossover suppression, similarly to satellite-based centromeres. These results suggest that the centromere effect does not depend on satellite DNA. During this analysis, we observed a peculiar phenomenon: while, as expected, the centromere of the majority of meiotic bivalent chromosomes was labelled with a single immunofluorescence centromeric signal, double-spotted or extended signals were also detected. Their number varied from 0 to 7 in different cells. This observation can be explained by positional variation of the centromeric domain on the two homologs and/or misalignment of pericentromeric satellite DNA arrays during homolog pairing confirming the great plasticity of equine centromeres

Sex predicts gut microbiota variations in wild yellow baboons

Microbiota research in wildlife has mainly focused on the investigation of extrinsic (e.g., diet, habitat) rather than intrinsic factors (e.g., sex, genetic background) affecting variation in host gut communities. However, since male and female mammals often differ in dietary requirements, sex is likely to play a major role in gut microbiota variation. Here, we analyzed the bacterial and fungal communities of 34 faecal samples of the sexually dimorphic yellow baboon (Papio cynocephalus) living in two contrasting forest types (intact/protected vs. fragmented/disturbed) in the Udzungwa Mountains of Tanzania. Sex was determined for each sample (19 females and 15 males) using the marker genes SRY and DDX3X; these results were then combined with those from two amplicon-sequencing datasets focusing on bacterial (V3-V4 region of the 16S rRNA gene) and fungal (ITS1-ITS2) communities from the same samples. We found that females had gut microbiotas with a higher bacterial richness [Kruskal test; Shannon (alpha diversity): P = 0.010] and different composition [ANOVA; weighted Unifrac (beta diversity): P = 0.030] compared to males. Furthermore, forest type had a greater impact on females than males, such that the gut microbiotas of females from the two forests differed significantly in fungal composition [pairwise adonis test; Bray-Curtis: P = 0.02] and bacterial richness [pairwise Wilcoxon Rank Sum test; Shannon: P = 0.023], while those of males did not. Our results suggest that intrinsic biological factors should be carefully considered when investigating wild animal microbiodiversity, and that such intraspecific variation could impact the outcome of conservation actions

CENP-A binding domains and recombination patterns in horse spermatocytes

Centromeres exert an inhibitory effect on meiotic recombination, but the possible contribution of satellite DNA to this "centromere effect" is under debate. In the horse, satellite DNA is present at all centromeres with the exception of the one from chromosome 11. This organization of centromeres allowed us to investigate the role of satellite DNA on recombination suppression in horse spermatocytes at the stage of pachytene. To this aim we analysed the distribution of the MLH1 protein, marker of recombination foci, relative to CENP-A, marker of centromeric function. We demonstrated that the satellite-less centromere of chromosome 11 causes crossover suppression, similarly to satellite-based centromeres. These results suggest that the centromere effect does not depend on satellite DNA. During this analysis, we observed a peculiar phenomenon: while, as expected, the centromere of the majority of meiotic bivalent chromosomes was labelled with a single immunofluorescence centromeric signal, double-spotted or extended signals were also detected. Their number varied from 0 to 7 in different cells. This observation can be explained by positional variation of the centromeric domain on the two homologs and/or misalignment of pericentromeric satellite DNA arrays during homolog pairing confirming the great plasticity of equine centromeres

First vegetation-plot database of woody species from Huíla province, SW Angola

Angola is a country in south-central Africa, particularly rich in biodiversity. Despite the efforts recently made to document its biodiversity, there is a need for standardized sampling methods to document and compare the variety of ecosystems and plants occurring in the country. With this database report we aim to document the abundance and diversity of woody species in the woodlands of Huíla province. The database hosts the results of a standardised plot-based vegetation survey, consisting of 448 vegetation plots distributed throughout the 14 municipalities and Bicuar National Park. In total, 40,009 individuals belonging to 44 plant families were recorded and measured, belonging to 193 woody species. Species richness per municipality ranged from 32 to 126. The mean stem diameter (DBH) was 10.9 cm ± 7.5 cm. Small-size classes are increasingly dominated by few species, while the largest trees come from a wider range of species; miombo key-species dominated almost all size classes. Our study represents the first plot-based vegetation survey of any Angolan province and constitutes a useful source of information for conservation and management. Additionally, may constitute a powerful dataset to support future studies on biodiversity patterns and vegetation change over time and facilitate the elaboration of vegetation maps. Taxonomic reference: Checklist of Angolan Plants (Figueiredo and Smith 2008), The African Plant Database (version 3.4.0) and A new classification of Leguminosae (LPWG 2017). Abbreviations: DBH = Diameter at Breast Height; GIVD = Global Index of Vegetation-Plot Databases; LUBA = Acronym of the Herbarium of Lubang