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Dr. Rafael Ferreira dos Santos
Department of Entomology and plant pathology University of Tennessee-Knoxville

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Research Keywords & Expertise

0 Bacillus thuringiensis
0 insecticidal activity
0 Insect Resistance management
0 insecticidal protein
0 Insect physiology

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Journal article
Published: 04 February 2020 in Toxins
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The bacterium Bacillus thuringiensis produces insecticidal Vip3 proteins during the vegetative growth phase with activity against several lepidopteran pests. To date, three different Vip3 protein families have been identified based on sequence identity: Vip3A, Vip3B, and Vip3C. In this study, we report the construction of chimeras by exchanging domains between Vip3Aa and Vip3Ca, two proteins with marked specificity differences against lepidopteran pests. We found that some domain combinations made proteins insoluble or prone to degradation by trypsin as most abundant insect gut protease. The soluble and trypsin-stable chimeras, along with the parental proteins Vip3Aa and Vip3Ca, were tested against lepidopteran pests from different continents: Spodoptera exigua, Spodoptera littoralis, Spodoptera frugiperda, Helicoverpa armigera, Mamestra brassicae, Anticarsia gemmatalis, and Ostrinia furnacalis. The exchange of the Nt domain (188 N-terminal amino acids) had little effect on the stability and toxicity (equal or slightly lower) of the resulting chimeric protein against all insects except for S. frugiperda, for which the chimera with the Nt domain from Vip3Aa and the rest of the protein from Vip3Ca showed a significant increase in toxicity compared to the parental Vip3Ca. Chimeras with the C-terminal domain from Vip3Aa (from amino acid 510 of Vip3Aa to the Ct) with the central domain of Vip3Ca (amino acids 189–509 based on the Vip3Aa sequence) made proteins that could not be solubilized. Finally, the chimera including the Ct domain of Vip3Ca and the Nt and central domain from Vip3Aa was unstable. Importantly, an insect species tolerant to Vip3Aa but susceptible to Vip3Ca, such as Ostrinia furnacalis, was also susceptible to chimeras maintaining the Ct domain from Vip3Ca, in agreement with the hypothesis that the Ct region of the protein is the one conferring specificity to Vip3 proteins.

ACS Style

Joaquín Gomis-Cebolla; Rafael Ferreira dos Santos; Yueqin Wang; Javier Caballero; Primitivo Caballero; Kanglai He; Juan Jurat-Fuentes; Juan Ferré. Domain Shuffling between Vip3Aa and Vip3Ca: Chimera Stability and Insecticidal Activity against European, American, African, and Asian Pests. Toxins 2020, 12, 99 .

AMA Style

Joaquín Gomis-Cebolla, Rafael Ferreira dos Santos, Yueqin Wang, Javier Caballero, Primitivo Caballero, Kanglai He, Juan Jurat-Fuentes, Juan Ferré. Domain Shuffling between Vip3Aa and Vip3Ca: Chimera Stability and Insecticidal Activity against European, American, African, and Asian Pests. Toxins. 2020; 12 (2):99.

Chicago/Turabian Style

Joaquín Gomis-Cebolla; Rafael Ferreira dos Santos; Yueqin Wang; Javier Caballero; Primitivo Caballero; Kanglai He; Juan Jurat-Fuentes; Juan Ferré. 2020. "Domain Shuffling between Vip3Aa and Vip3Ca: Chimera Stability and Insecticidal Activity against European, American, African, and Asian Pests." Toxins 12, no. 2: 99.

Articles
Published: 01 March 2016 in Brazilian Journal of Biology
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Mass production of predatory stinkbugs in the laboratory is prioritized to release them into the field as part of IPM programs. Therefore, the aim of this study was to identify the best prey for rearing the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) among five different species of insect (three of Lepidoptera, one of Coleoptera, and one of Diptera). Second-instar P. nigrispinus nymphs were conditioned in transparent 1000-mL plastic pots, adults were placed in Petri dishes for mating, and both stages were maintained under controlled conditions (25 ± 1°C, 12 hours of photophase, 70 ± 10% RH). Nymphs and adults of P. nigrispinus consumed more Musca domestica (Linnaeus, 1758) (Diptera: Muscidae) larvae than the other tested prey. The consumption of fly larvae was 1.5 larvae/day/nymph and adults 1.7 larvae/day/adult. However, the number of eggs per female was less when the predator consumed M. domestica larvae (407.8 eggs/female) and most when consumed the Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) larvae (797.7 eggs/female). Furthermore, the percentage of hatched eggs was greater when the predator females consumed D. saccharalis larvae (90.0%). D. saccharalis larvae is the best prey to rearing P. nigrispinus.

ACS Style

S. A. De Bortoli; A. M. Vacari; V. L. Laurentis; Rafael Ferreira dos Santos; A. K. Otuka. Selection of prey to improve biological parameters of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) in laboratory conditions. Brazilian Journal of Biology 2016, 76, 307 -314.

AMA Style

S. A. De Bortoli, A. M. Vacari, V. L. Laurentis, Rafael Ferreira dos Santos, A. K. Otuka. Selection of prey to improve biological parameters of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) in laboratory conditions. Brazilian Journal of Biology. 2016; 76 (2):307-314.

Chicago/Turabian Style

S. A. De Bortoli; A. M. Vacari; V. L. Laurentis; Rafael Ferreira dos Santos; A. K. Otuka. 2016. "Selection of prey to improve biological parameters of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) in laboratory conditions." Brazilian Journal of Biology 76, no. 2: 307-314.

Journal article
Published: 17 April 2015 in Journal of Economic Entomology
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In Brazil, the parasitoid Cotesia flavipes (Cameron) has been used as a biological control agent against Diatraea saccharalis (F.) since 1976, because of its effectiveness in reducing populations of this pest. Three million plastic cups are used annually to release C. flavipes, which remain in the environment. This study aimed to develop fully biodegradable packaging, so that releases occur without damaging the environment. The biological characteristics of C. flavipes were studied for five generations in the packaging developed (biodegradable boxes) and in the packaging currently used (non-biodegradable plastic cups and biodegradable cups), as were the costs. The results demonstrated the feasibility of using completely biodegradable and inexpensive packaging for the rearing, transport, and release of adult C. flavipes in the field.

ACS Style

Rafael Ferreira dos Santos; Alessandra M. Vacari; Sergio De Bortoli; Caroline P. De Bortoli; Josy A. Santos. Development of a New Container for Storage and Release of the Parasitoid Cotesia flavipes (Hymenoptera: Braconidae). Journal of Economic Entomology 2015, 108, 969 -974.

AMA Style

Rafael Ferreira dos Santos, Alessandra M. Vacari, Sergio De Bortoli, Caroline P. De Bortoli, Josy A. Santos. Development of a New Container for Storage and Release of the Parasitoid Cotesia flavipes (Hymenoptera: Braconidae). Journal of Economic Entomology. 2015; 108 (3):969-974.

Chicago/Turabian Style

Rafael Ferreira dos Santos; Alessandra M. Vacari; Sergio De Bortoli; Caroline P. De Bortoli; Josy A. Santos. 2015. "Development of a New Container for Storage and Release of the Parasitoid Cotesia flavipes (Hymenoptera: Braconidae)." Journal of Economic Entomology 108, no. 3: 969-974.

Journal article
Published: 01 June 2011 in Horticultura Brasileira
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O objetivo desta pesquisa foi comparar diferentes cultivares de brassicáceas em relação à capacidade reprodutiva e preferência para alimentação e oviposição da traça-das-crucíferas. Os experimentos foram realizados utilizando-se as cultivares de repolho Midori, Chato-de-Quintal, híbridos da Top Seed® - Agristar (TPC 308, TPC 681 e TPC 668), couve-flor Bola de Neve, couve brócolis Ramoso Piracicaba Precoce e couve Manteiga da Geórgia, sendo esta última utilizada como padrão de suscetibilidade. Por meio dos dados biológicos de P. xylostella foram estimados os parâmetros necessários para a construção de tabela de vida de fertilidade, para comparação das cultivares testadas em relação à capacidade reprodutiva da praga. Em gaiolas de criação da traça-das-crucíferas foram colocados quatro quartos de folha, dois a dois, que justapostos formavam um círculo de 8 cm de diâmetro, confrontando-se os materiais dois a dois. As partes foram dispostas equidistantemente, para realização do teste de dupla chance de escolha (preferência para alimentação e oviposição) e de múltipla chance de escolha, confrontando todos os substratos (preferência para alimentação). As cultivares que proporcionaram melhor desenvolvimento e reprodução para a traça-das-crucíferas foram couve Manteiga da Geórgia e couve brócolis. Para preferência alimentar constatou-se alta suscetibilidade em couve Manteiga e TPC 681 e para preferência de oviposição alta preferência para couve-flor Bola de Neve. Com isso, sugere-se a divisão das cultivares estudadas em quatro classes distintas: repolho Midori como moderadamente resistente (MR); couve-flor Bola de Neve e repolho Chato-de-Quintal como suscetíveis (S); couve brócolis, TPC308, TPC681 e TPC668 como moderadamente suscetíveis (MS); e couve Manteiga como altamente suscetível (AS).

ACS Style

Sergio A De Bortoli; Alessandra M Vacari; Roberto M Goulart; Rafael Ferreira dos Santos; Haroldo Xl Volpe; Antonio S Ferraudo. Capacidade reprodutiva e preferência da traça-das-crucíferas para diferentes brassicáceas. Horticultura Brasileira 2011, 29, 187 -192.

AMA Style

Sergio A De Bortoli, Alessandra M Vacari, Roberto M Goulart, Rafael Ferreira dos Santos, Haroldo Xl Volpe, Antonio S Ferraudo. Capacidade reprodutiva e preferência da traça-das-crucíferas para diferentes brassicáceas. Horticultura Brasileira. 2011; 29 (2):187-192.

Chicago/Turabian Style

Sergio A De Bortoli; Alessandra M Vacari; Roberto M Goulart; Rafael Ferreira dos Santos; Haroldo Xl Volpe; Antonio S Ferraudo. 2011. "Capacidade reprodutiva e preferência da traça-das-crucíferas para diferentes brassicáceas." Horticultura Brasileira 29, no. 2: 187-192.