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PROGRAMA DOUTORAL EM BIOLOGIA E ECOLOGIA DAS ALTERAÇÕES GLOBAIS DA UNIV. DE AVEIRO
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Association between reproduction and immunity in Herpestes ichneumon is sex‐biased and unaffected by body condition
Publication . Bandeira, V.; Virgós, E.; Azevedo, A.; Cunha, Mónica V.; Fonseca, C.
The Egyptian mongoose (Herpestes ichneumon) is a carnivore in expansion on the western limits of Europe, where its reproductive ecology is unknown. In this study, we weighed and measured the gonads of 507 wild‐caught mongooses ranging its geographical distribution and all seasons of the year. Based on the variation in gonad weight, we determined periods of reproductive activity for females (December–June) and males (throughout the year), with both sexes showing a peak in gonad weight during February. We also identified periods of lactation (March‐August, n = 10), gestation (December–July, n = 20) and mean litter size (1–4 offspring, 2.75 ± 0.79, n = 20). Next, we constructed two separate models to explain the variation in ovarian and testicular weight, using age cohort, season and region, spleen weight, body condition and the environmental variables habitat, river network and Egyptian mongoose density as predictors. Ovarian weight was influenced by season and spleen weight. Females with heavier ovaries were found in spring and simultaneously exhibited heavier spleens. Testicular weight was influenced by season, spleen weight and age, as well as several environmental variables. Males with lower spleen weight exhibited heavier testes, indicating a male‐specific negative association between reproductive and immune activity. Overall, the results of this study refine our knowledge on Egyptian mongoose reproductive ecology. They indicate that reproduction timing is determined by females, whose breeding is seasonal but who are unaffected by the set of environmental variables we tested, as opposed to males, who are influenced by these environmental conditions and seem to be reproductively active year round. These results also support a negative reproduction‐immunity trade‐off in males, that is independent of body condition and absent in females.
Egyptian Mongoose (Herpestes ichneumon) Gut Microbiota: Taxonomical and Functional Differences across Sex and Age Classes
Publication . Pereira, André C.; Bandeira, Victor; Fonseca, Carlos; Cunha, Mónica V.
The Egyptian mongoose (Herpestes ichneumon) is a medium-size carnivore that, in Europe, is restricted to Iberia. The bio-ecology of this species remains to be elucidated in several dimensions, including gut microbiota that is nowadays recognized as a fundamental component of mammals. In this work, we investigated the gut microbiota of this herpestid by single-molecule real-time sequencing of twenty paired male (n = 10) and female (n = 10) intestinal samples. This culture-independent approach enabled microbial profiling based on 16S rDNA and investigation of taxonomical and functional features. The core gut microbiome of the adult subpopulation was dominated by Firmicutes, Fusobacteria, Actinobacteria, and Proteobacteria. Eight genera were uniquely found in adults and five in non-adults. When comparing gut bacterial communities across sex, four genera were exclusive of females and six uniquely found in males. Despite these compositional distinctions, alpha- and beta-diversity analyses showed no statistically significant differences across sex or between adult and non-adult specimens. However, when function was inferred, males presented a significantly higher abundance of amino acid and citrate cycle metabolic pathways, compared to the significant overrepresentation in females of galactose metabolic pathways. Additionally, adults exhibited a significantly higher abundance of cationic antimicrobial peptide resistance pathways, while non-adults bared a significant overrepresentation of two-component systems associated with antibiotic synthesis, flagellin and biofilm production, and chemotaxis control. This study adds new insights into the mongoose bio-ecology palette, highlighting taxonomical and functional microbiome dissimilarities across sex and age classes, possibly related to primary production resources and life-history traits that impact on behavior and diet.
Crosstalk Between Culturomics and Microbial Profiling of Egyptian Mongoose (Herpestes ichneumon) Gut Microbiome
Publication . Pereira, André C.; Bandeira, Victor; Fonseca, Carlos; Cunha, Mónica V.
Recently, we unveiled taxonomical and functional differences in Egyptian mongoose (Herpestes ichneumon) gut microbiota across sex and age classes by microbial profiling. In this study, we generate, through culturomics, extended baseline information on the culturable bacterial and fungal microbiome of the species using the same specimens as models. Firstly, this strategy enabled us to explore cultivable microbial community differences across sexes and to ascertain the influence exerted by biological and environmental contexts of each host in its microbiota signature. Secondly, it permitted us to compare the culturomics and microbial profiling approaches and their ability to provide information on mongoose gut microbiota. In agreement with microbial profiling, culturomics showed that the core gut cultivable microbiota of the mongoose is dominated by Firmicutes and, as previously found, is able to distinguish sex- and age class-specific genera. Additional information could be obtained by culturomics, with six new genera unveiled. Richness indices and the Shannon index were concordant between culture-dependent and culture-independent approaches, highlighting significantly higher values when using microbial profiling. However, the Simpson index underlined higher values for the culturomics-generated data. These contrasting results were due to a differential influence of dominant and rare taxa on those indices. Beta diversity analyses of culturable microbiota showed similarities between adults and juveniles, but not in the data series originated from microbial profiling. Additionally, whereas the microbial profiling indicated that there were several bioenvironmental features related to the bacterial gut microbiota of the Egyptian mongoose, a clear association between microbiota and bioenvironmental features could not be established through culturomics. The discrepancies found between the data generated by the two methodologies and the underlying inferences, both in terms of β-diversity and role of bioenvironmental features, confirm that culture-independent, sequence-based methods have a higher ability to assess, at a fine scale, the influence of abiotic and biotic factors on the microbial community composition of mongoose' gut. However, when used in a complementary perspective, this knowledge can be expanded by culturomics.
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Fundação para a Ciência e a Tecnologia
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SFRH/BD/51540/2011