Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto

About: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto is a based out in . It is known for research contribution in the topics: Population & Catalysis. The organization has 2143 authors who have published 3674 publications receiving 71071 citations. The organization is also known as: FFCLRP & FFCLRP-USP.

Parasites and Symbionts of Crabs from Ubatuba Bay, São Paulo State, Brazil

Abstract: During July 1999, 172 crabs from Ubatuba Bay, Sao Paulo, Brazil, were examined from 4 families as follows: Portunidae, Arenaeus cribrarius, Callinectes danae, Callinectes ornatus, Charybdis hellerii, Portunus spinimanus, and Portunus spinicarpus; Calappidae, Hepatus pudibundus; Majidae, Libinia ferreirae; Leucosiidae, Persephona mediterranea and Persephona lichtensteinii. One cephaline gregarine symbiont was found in the hindgut of a specimen of Cal. ornatus, and no positively identified, internal and multicelled symbionts were detected. Twenty-one specimens (14.3%) from 7 of the 10 species (all except H. pudibundus, P. mediterranea, and P. lichtensteinii) carried the nemertean worm, Carcinonemertes carcinophila ct. imminuta in either their egg masses or gills. This is the first report of this epibiont from the Ubatuba region. Two specimens of an undescribed polychaete worm were found in the gill of a specimen of L. ferreirae. A stalked barnacle, Octolasmis lowei, was found on the gills of 11 crabs (7.5%). Only 3 crab species (36.6% of Cal. danae, 9.0% of Cal. ornatus, and 7.7% of Po. spinimanus) carried the typical barnacle, Chelonibia patula, on their dorsal carapaces. The percentage of individuals of Cal. danae and Cal. ornatus hosting barnacles (prevalence) as well as the number of barnacles on individual crabs was positively correlated with crab size.

Numerical investment in sex and caste by stingless bees (Apidae: Meliponini): a comparative analysis

Abstract: L'investissement dans le nombre d'ouvrieres, de gynes (jeunes reines non fecondees), et de mâles a ete etudiee chez certaines especes d'abeilles sans aiguillon. Nous avons essaye de mettre en relief l'importance des ouvrieres chez ces insectes sociaux dont les colonies sont fondees par un essaim, en raison de leurs roles dans la maintenance et la croissance de la colonie et dans l'essaimage. L'approche choisie se base sur la structure de modeles de l'affectation des ressources publies par Pamilo (1991), Reuter et Keller (2001), Wenseleers et al. (2003). On a confronte les especes qui construisent des cellules royales (RCP : Plebeia remota et Schwarziana quadripunctata) et celles qui n'en construisent pas (RCA : Melipona asilvai, M. bicolor et M. subnitida) eu egard aux affectations en proportions et en nombres dans les sexes et les castes. La production d'individus a ete etudiee par l'examen des nymphes vivantes dans les rayons de couvain (unites d'echantillonnage, Tab. I). Le nombre total de cellules est la somme des gynes, des mâles et des ouvrieres et peut etre represente par un modele additif de regression lineaire pour estimer l'investissement en nombre (Tab. II). Chez les especes RCA, les femelles sexuees, les mâles et les ouvrieres sont produits dans 92 %, 54 % et 100 % respectivement des rayons de couvain (n = 141); pour les especes RCP, les chiffres sont de 29 %, 62 % et 98 %. Il y a des differences significatives entre les groupes dans les affectations en proportion (Tab. III) aux gynes (pg), aux gynes au sein des femelles (z), aux ouvrieres au sein de femelles (1 - z) et aux mâles au sein des individus reproducteurs (sex-ratio), mais pas dans les affectations en proportion aux mâles (p m ), aux ouvrieres (p w ), aux femelles (1 - p m ) et aux individus reproducteurs (1- p w ). Les especes RCA ont presente des valeurs plus elevees que les RCP seulement pour pg et z. On a examine la relation entre z et p m , comme dans Wenseleers et al. (2003). On a trouve une tendance vers une correlation positive pour les especes RCA (P = 0,062), mais rien pour les especes RCP. Aucun des groupes n'a montre de correlation entre l'affectation proportionnelle a p m et 1 - z. Les pentes des regressions lineaires entre couples de variables ont montre des investissements en nombre differents entre groupes (Tab. IV). Chez les especes RCA les pentes (en nombres proportionnels) ont ete significativement plus elevees pour les couples femelles/cellules, gynes/femelles, gynes/mâles et ouvrieres/cellules. Chez les especes RCP elles etaient significativement plus elevees pour les couples mâles/cellules, mâles/femelles, ouvrieres/femelles, gynes/ouvrieres, mâles/ouvrieres, individus reproducteurs/cellules et individus reproducteurs/ouvrieres. Aucune difference significative n'a ete trouvee entre les pentes pour le couple gynes/cellules. Les especes RCA ont eu un investissement en nombre plus important dans les gynes que les RCP (6,0 % contre 0,08 % des cellules totales). Dans les deux groupes des correlations negatives ont ete trouvees entre les affectations residuelles aux mâles par rapport aux ouvrieres. Il y a une correlation negative entre les affectations residuelles aux gynes par rapport aux ouvrieres chez les especes RCA mais pas chez les RCP, ce qui corrobore le modele de Wenseleers et al. (2003).

Effects of food limitation and temperature on cladocerans from a tropical Brazilian lake

Abstract: Food limitation was tested in the laboratory by individual growth and reproduction of two cladoceran species, Ceriodaphnia richardi and Daphnia gessneri, from the shallow tropical Brazilian Lake Monte Alegre The cladocerans were fed cultivated green alga Scenedesmus spinosus in concentrations of 020, 010, 005, and 0025 mg C l−1 Higher biomass and growth rates occurred in the two highest-food concentrations; the two lowest ones negatively affected clutch size and first reproduction The threshold food concentration is lower than 0025 mg C l−1 and the incipient limiting level is a value between 010 and 020 mg C l−1 The largest species, D gessneri, was more sensitive to low food concentrations The effects of low and high temperatures (19 and 27°C) were evaluated by life table experiments with three cladocerans from the lake—Daphnia ambigua, D gessneri, and Moina micrura—with no food limitation (1 mg C l−1 of S spinosus) Higher population growth rates for the three species were found at 27°C; better performance in most life table parameters was observed for the former two species at the highest temperature, D gessneri being the most sensitive to the lowest temperature There are indications that temperature is an important abiotic factor that constrains populations of cladocerans for a short period in winter in the lake, when temperature decreases to 18–19°C However, its influence cannot be separated from a biotic factor such as food, whose effect is stronger in the cool season, when concentrations are lower and contribution of inedible algae is relatively higher

Genes involved in thoracic exoskeleton formation during the pupal-to-adult molt in a social insect model, Apis mellifera

Abstract: The insect exoskeleton provides shape, waterproofing, and locomotion via attached somatic muscles. The exoskeleton is renewed during molting, a process regulated by ecdysteroid hormones. The holometabolous pupa transforms into an adult during the imaginal molt, when the epidermis synthe3sizes the definitive exoskeleton that then differentiates progressively. An important issue in insect development concerns how the exoskeletal regions are constructed to provide their morphological, physiological and mechanical functions. We used whole-genome oligonucleotide microarrays to screen for genes involved in exoskeletal formation in the honeybee thoracic dorsum. Our analysis included three sampling times during the pupal-to-adult molt, i.e., before, during and after the ecdysteroid-induced apolysis that triggers synthesis of the adult exoskeleton. Gene ontology annotation based on orthologous relationships with Drosophila melanogaster genes placed the honeybee differentially expressed genes (DEGs) into distinct categories of Biological Process and Molecular Function, depending on developmental time, revealing the functional elements required for adult exoskeleton formation. Of the 1,253 unique DEGs, 547 were upregulated in the thoracic dorsum after apolysis, suggesting induction by the ecdysteroid pulse. The upregulated gene set included 20 of the 47 cuticular protein (CP) genes that were previously identified in the honeybee genome, and three novel putative CP genes that do not belong to a known CP family. In situ hybridization showed that two of the novel genes were abundantly expressed in the epidermis during adult exoskeleton formation, strongly implicating them as genuine CP genes. Conserved sequence motifs identified the CP genes as members of the CPR, Tweedle, Apidermin, CPF, CPLCP1 and Analogous-to-Peritrophins families. Furthermore, 28 of the 36 muscle-related DEGs were upregulated during the de novo formation of striated fibers attached to the exoskeleton. A search for cis-regulatory motifs in the 5′-untranslated region of the DEGs revealed potential binding sites for known transcription factors. Construction of a regulatory network showed that various upregulated CP- and muscle-related genes (15 and 21 genes, respectively) share common elements, suggesting co-regulation during thoracic exoskeleton formation. These findings help reveal molecular aspects of rigid thoracic exoskeleton formation during the ecdysteroid-coordinated pupal-to-adult molt in the honeybee.