RESUMEN
A new species of Astyanax is described from the upper Rio Paraguai basin, Mato Grosso State, Brazil. The new species can be distinguished from congeners by having the body intensely yellowish in life (v. silvery, reddish or lightly yellow) and by morphometric and meristics traits. Astyanax dolinae n. sp. cannot be assigned to any of the Astyanax species complex currently recognized for the genus. It is only known from the Dolina Água Milagrosa, a karstic sinkhole lake, entirely fed by groundwater, surrounded by Cerrado, the savannah-like vegetation of central South America.
Asunto(s)
Characidae/clasificación , Animales , Brasil , Characidae/anatomía & histología , Ecosistema , Lagos , Aislamiento Social , Especificidad de la EspecieRESUMEN
Conventional and genetically modified (GM) maize cultivars have been widely planted in Brazil to produce grains for processed food, feed, or to be consumed fresh as corn ears. This study used real-time PCR to detect GM maize in processed products and fresh commercial corn ears produced in the last two years in South Brazil. Eighteen conventional and GM maize cultivars were obtained from seed production companies and 50 commercial samples (including canned corn, corn flour, dry grains, and fresh corn ears) were purchased in small local stores and supermarkets. All samples were analyzed by real time TaqMan PCR to detect one constitutive maize gene (hmg) and three genetic regions present in GM plants (p-35S promoter, major gene cry 1A.105, and t-Nos terminator). Each commercial sample was classified as conventional or GM based on the PCR results. PCR targeting the hmg gene generated positive results from all DNA samples, which were further tested with the GM targets. These targets were not detected in the five conventional maize cultivars, but were detected in the GM seeds hosting these fragments. Analysis of processed foods identified four cultivars as conventional and six as GM, which were mostly correctly labeled. Seven (53.8%) dry grain samples were classified as conventional, while six (46.2%) were classified as GM. Three (11.1%) corn ear samples were identified as conventional, and the remaining 24 (88.9%) were GM maize. These results demonstrate the high frequency of GM maize in processed products, including fresh corn ears intended for consumption in South Brazil.
Asunto(s)
Semillas/genética , Zea mays/anatomía & histología , Zea mays/genética , Brasil , Geografía , Plantas Modificadas Genéticamente , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Cytogenetic studies in Gymnothorax funebris revealed a diploid chromosome number 2n = 42 (6 metacentrics, 4 submetacentrics, and 32 acrocentrics, FN = 52). The results obtained are novel and similar to those previously described for species belonging to Muraenidae family. The conventional karyotype is also novel and divergent from other species of the genus Gymnothorax, where a higher proportion of metacentric chromosomes predominate. The data are reported and discussed considering the cytotaxonomy of the genus. These results strongly support the current view that chromosomal alterations such as centric fusion and Robertsonian's translocations have an important role in the evolution of this group.