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Biology subjects

Santos, N. F.

Publications and source records attributed to Santos, N. F..

2 recordsLinked to original sources

Bloodmeal metabarcoding of the argasid tick (Ornithodoros turicata Duges) reveals extensive vector-host associations

Molecular methods to understand host feeding patterns of arthropod vectors are critical to assess exposure risk to vector-borne disease and unveil complex ecological interactions. We build on our prior work discovering the utility of PCR-Sanger sequencing bloodmeal analysis that work remarkably well for soft ticks (Acari: Argasidae), unlike for hard ticks (Acari: Ixodidae), thanks to their unique physiology that retains vertebrate DNA from prior bloodmeals viable for years. Here, we capitalize on this feature and apply bloodmeal metabarcoding using amplicon deep sequencing to identify multiple host species in individual Ornithodoros turicata soft ticks collected from two natural areas in Texas, United States. Of 788 collected O. turicata, 394 were evaluated for bloodmeal source via metabarcoding, revealing 27 different vertebrate host species (17 mammals, 5 birds, 1 reptile, and 4 amphibians) fed upon by 274 soft ticks. Information on multiple hosts for individual O. turicata was derived from 168 of these (61%). Metabarcoding revealed more mixed vertebrate bloodmeals in O. turicata previously processed using Sanger sequencing. These data reveal wide host range of O. turicata and demonstrate the value of bloodmeal metabarcoding for understanding the ecology for known and potential tick-borne pathogens circulating among humans, domestic animals and wildlife such as relapsing fever caused by Borrelia turicatae. Our results also document, for the first time an off-host soft tick collected to have evidence of prior feeding on wild pig which is a critical observation in the context of the threat of enzootic transmission of African swine fever virus if it were introduced to the US. This research enhances our understanding of vector-host associations and offers a promising perspective for biodiversity monitoring and disease control strategies.

ecology↗

Candidate proteins associated with popping expansion capacity of popcorn

The mechanical resistance of the popcorn pericarp has a positive and direct relationship to its expansion volume. It allows enough time for the endosperm to gelatinize completely before its extravasation. Expansion is a polygenic trait that has been extensively studied. However, no records in the literature indicate proteins that directly affect pericarp thickness and integrity. Therefore, the present work aimed to identify candidate pericarp proteins associated with the expansion capacity of popcorn kernels using the shotgun proteomic approach. The analyses were carried out in the pericarp of two popcorn inbred lines, P11 (expansion volume of 30 mL g-1) and P16 (expansion volume of 14 mL g-1), in two developmental stages (15 and 25 DAP). A total of 803 non-redundant proteins were identified. Most of them were involved in key processes associated with pericarp development and thickening. Two candidate proteins stood out among the differentially abundant proteins. Peroxidase was up-accumulated in P11/25 DAP (high popping expansion) and was 1.498 times more abundant in this inbred line, while xyloglucan endotransglucosylase/hydrolase was more abundant in P16 (low popping expansion) in both developmental stages. Thus, the peroxidase protein increases expandability, whereas xyloglucan endotransglucosylase/hydrolase decreases it, even though its specific role has not been elucidated. These proteins should be further investigated, as they may be used to improve expansion capacity in popcorn breeding programs.

genomics↗