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Pereira, L. M.

Publications and source records attributed to Pereira, L. M..

3 recordsLinked to original sources

Genomic Skimming and Nanopore Sequencing Uncover Cryptic Hybridization in One of World's Most Threatened Primates

The Brazilian buffy-tufted-ear marmoset (Callithrix aurita), one of the worlds most endangered primates, is threatened by anthropogenic hybridization with exotic, invasive marmoset species. As there are few genetic data available for C. aurita, we developed a PCR-free protocol with minimal technical requirements to rapidly generate genomic data with genomic skimming and portable nanopore sequencing. With this direct DNA sequencing approach, we successfully determined the complete mitogenome of a marmoset that we initially identified as C. aurita. The obtained nanopore-assembled sequence was highly concordant with a Sanger sequenced version of the same mitogenome. Phylogenetic analyses unexpectedly revealed that our specimen was a cryptic hybrid, with a C. aurita phenotype and C. penicillata mitogenome lineage. We also used publicly available mitogenome data to determine diversity estimates for C. aurita and three other marmoset species. Mitogenomics holds great potential to address deficiencies in genomic data for endangered, non-model species such as C. aurita. However, we discuss why mitogenomic approaches should be used in conjunction with other data for marmoset species identification. Finally, we discuss the utility and implications of our results and genomic skimming/nanopore approach for conservation and evolutionary studies of C. aurita and other marmosets.

evolutionary biology↗

Neuroimmune circuits involved in β-lactoglobulin-induced food allergy

Cows milk allergy is the most prevalent food allergy that usually begins early in life and {beta}- lactoglobulin (BLG) is the milk component with the highest allergenicity. It has been described that ovalbumin (OVA)-induced food allergy in mice is associated with anxiety and aversive behavior. However, it is yet to be determined whether altered behavior is a general component of food allergy or whether it is specific for some types of allergens. Thus, we investigated behavioral and neuroimmune circuits triggered by allergic sensitization to BLG. We found a neuroimmune conflict between aversion and reward in a model of food allergy induced to BLG. Mice sensitized to BLG did not present aversive behavior when the allergen was used for sensitization and oral challenge. Mice allergic to BLG preferred to drink the allergen-containing solution over water even though they presented high levels of specific IgE, inflammatory cells in the intestinal mucosa and significant weight loss. When sensitized to OVA and orally challenged with the same antigen, mice had display neuron activation in the amygdala suggesting an anxiety-related sensation. On the other hand, OVA-sensitized mice showed preference to consume a mixture of BLG and OVA during oral challenge in spite of their aversion to OVA. Consumption of OVA-BLG solution was associated with neuron activation in the nucleus accumbens, suggesting a reward sensation. Thus, the aversive behavior observed in food allergy to OVA does not apply to all antigens and some allergens may induce preference rather than aversion. Our study provides new insights into the neuroimmune conflicts regarding preference and avoidance to a common antigen associated with food allergy.

immunology↗

Population structure of modern-day Italians reveals patterns of ancient and archaic ancestries in Southern Europe

European populations display low genetic diversity as the result of long term blending of the small number of ancient founding ancestries. However it is still unclear how the combination of ancient ancestries related to early European foragers, Neolithic farmers and Bronze Age nomadic pastoralists can fully explain genetic variation across Europe. Populations in natural crossroads like the Italian peninsula are expected to recapitulate the overall continental diversity, but to date have been systematically understudied. Here we characterised the ancestry profiles of modern-day Italian populations using a genome-wide dataset representative of modern and ancient samples from across Italy, Europe and the rest of the world. Italian genomes captured several ancient signatures, including a non-steppe related substantial ancestry contribution ultimately from the Caucasus. Differences in ancestry composition as the result of migration and admixture generated in Italy the largest degree of population structure detected so far in the continent and shaped the amount of Neanderthal DNA present in modern-day populations.\n\nOne sentence summaryAncient and historical admixture events shaped the genetic structure of modern-day Italians, the ancestry profile of Southern European populations and the continental distribution of Neanderthal legacy.

genomics↗