Biology subjects

Paiva, M.

Publications and source records attributed to Paiva, M..

4 recordsLinked to original sources

bioRxiv2026

Domestication drives changes in floral functional traits that impact generalist pollinator visitation

Crop domestication is an evolutionary process that has led to extraordinary plant phenotypic changes in response to artificial selection. The extent to which domestication has altered floral phenotypes and the implications of these changes for plant-pollinator interactions remain unclear. Here, we characterized the floral phenotypes of wild and domesticated species in the genus Cucurbita (squash and pumpkins) and quantified their relative attractiveness to generalist and specialist pollinators. Our results show that functional floral traits change with domestication and that some of these changes impact the visitation of generalist pollinators but not specialists. Crops displayed larger flowers with shorter anthers and wider corollas, lower volatile richness, higher sugar content in pollen, and lower sucrose:glucose ratios in nectar. These trait shifts were associated with pollinator behavior in generalist pollinators, which preferentially visited domesticated flowers. We demonstrate that domestication alters functional plant traits and that these changes affect generalist pollinator preference in agricultural settings.

ecology↗

bioRxiv2023

Ecological monitoring using Collembola metabarcoding with extremely low bycatch amplification.

Collembola are used widely to monitor soil health and functional parameters. Recent developments in high throughput sequencing (especially metabarcoding) have substantially increased their potential for these ends. Collembola are especially amenable to metabarcoding because of their small size, high abundance, and ubiquity in most habitat types. However, most Collembola sampling protocols collect a substantial and highly varied bycatch that can be a considerable impediment to metabarcoding, especially because of data lost to non-target species. We designed a primer set amplifying the D2 expansion segment of ribosomal DNA that is highly conserved across Collembola and successfully excludes from amplification nearly all other invertebrate taxa. We tested the diagnostic power of the primer set by clearly distinguishing Collembola communities between forest sites with differing habitat qualities in Sao Paulo State, Brazil. The oligos successfully amplified targets from all Collembola orders previously encountered in the sampling locations, with no non-target amplification, and also excluded the closely related Protura and Diplura. Alpha diversity (OTU count) and phylogenetic diversity was significantly higher in high quality habitats. Moreover, the beta diversity indices successfully differentiated high and low-quality habitats. This new addition to the biomonitoring toolbox greatly increases the accessibility of Collembola metabarcoding for various types of habitat assessments.

molecular biology↗

bioRxiv2020

A cytokine network balance influences the fate of Leishmania (Viannia) braziliensis infection in a cutaneous leishmaniasis hamster model

The golden hamster is a suitable model for studying cutaneous leishmaniasis (CL) due to Leishmania (Viannia) braziliensis. Immunopathological mechanismsare wellstablished inthe L. (L.) major-mouse model, in which IL-4 instructs a Th2 response towards progressive infection. In the present study, we evaluatedthe natural history of L. braziliensis infection from its first stagesup to lesion establishment, with the aim ofidentifyingimmunological parameters associated with the disease outcome and parasitismfate. To this end, hamsters infected with 104, 105,or 106 promastigoteswere monitored duringthe first hours (4h, 24h), early (15, 30 days) and late (50 days) post-infection (pi) phases. Cytokines, iNOS and arginasegene expression were quantified in the established lesions by RT-PCR. Compared to the 105 or 106 groups, 104animals presented lower lesions sizes, less tissue damage,and lower IgG levels. Basal gene expression in normal skin was high for TGF-{beta}, and intermediary for TNF, IL-6, and IL-4.At 4hpi, no cytokine induction was observed in the 104 group, while an upregulation of IL-6, IL-10, and IL-4 was observed in the 106 group. At 15dpi, lesion appearance was accompanied byan increasedexpression of all assessed cytokines, markedly in the 105 and 106 groups. Upregulation of all investigated cytokines was observed in the late phase, although less expressive in the 104 group. IFN-{gamma} was the depending variable influencing tissue damage, while IL-6 was associatedto parasite load. The network correlating gene expression and clinical and laboratorial parameters indicated inoculum-independent associations at 15 and 30dpi.A strong positive network correlation was observed in the 104 group, but not in the105 or 106 groups. In conclusion, IL-4, IL-6, IL-10, and TGF-{beta} are linkedto L. braziliensisprogression. However, a balanced cytokine network is the key for an immune response able to reduce the ongoing infection and reduce pathological damage.

immunology↗

bioRxiv2019

Prevalence of sleep-disordered breathing and associations with malocclusion in children

ObjectiveThis study aimed to determine the prevalence of sleep-disordered breathing (SDB) and its association with malocclusion among children in Recife, Brazil. Methods390 children aged seven to eight years took part in the study, comprised by the body mass measurement, orthodontic examination and parents information required by the Sleep Disturbance Scale for Children. Statistics tools were Pearsons chi-square and Lemeshow test. ResultsSDB was found in 33.3% of the children and associated with overjet (p= 0.007), anterior open bite (p=0.008) and posterior crossbite (p= 0.001). There was no association between BMI and SDB. The multivariate logistic regression model indicated that the anterior open bite (p= 0.002) and posterior crossbite (p = 0.014) have an association with SDB. ConclusionsResults of this study indicated that the prevalence of SDB was high and highly associated with malocclusion; anterior open bite and posterior crossbite are risk factors for SDB.

epidemiology↗