Although it is widely regarded that the targeting of RNA molecules to subcellular destinations depends upon the recognition of cis-elements found within their 3' untranslated regions (UTR), relatively little is known about the specific features of these cis-sequences that underlie their function. Interaction between specific repeated motifs within the 3' UTR and RNA-binding proteins has been pr...

The aim of this study was to assess the major food items ingested by adult specimens of Daphnia laevis within the eutrophic Pampulha reservoir in Belo Horizonte, Minas Gerais, Brazil. The gut content was analyzed after addition of sodium hypochlorite and also through the examination of dissected guts under scanning electron microscopy. The results showed that Chlorophyceae was the main food ite...

The use of quantum dots (QDs) for nanomedicine is hampered by their potential toxicologic effects and difficulties with delivery into the cell interior. We accomplished an in vivo study exploiting Daphnia magna and Xenopus laevis to evaluate both toxicity and uptake of QDs coated with the membranotropic peptide gH625 derived from the glycoprotein H of herpes simplex virus and widely used for dr...

As in many anurans, males of the totally aquatic species, Xenopus laevis, advertise their sexual receptivity using vocalizations. Unusually for anurans, X. laevis females also advertise producing a fertility call that results in courtship duets between partners. Although all X. laevis calls consist of repetitive click trains, male and female calls exhibit sex-specific acoustic features that mig...

Husbandry and health of the African clawed frog, Xenopus laevis, greatly influences the quality of oocytes produced. One factor affecting oocyte quality is the water conditions in which females are maintained. Dechlorination and adequate salt concentration are known to affect oocytes, but water hardness has not been considered an important factor in Xenopus husbandry by the research community. ...

Previous studies characterized macromolecular differences between Xenopus and Rana transcription factor IIIA (TFIIIA) (Gaskins et al., 1989, Nucl. Acids Res. 17, 781-794). In the present study, cDNAs for TFIIIA from Xenopus borealis and Rana catesbeiana (American bullfrog) were cloned and sequenced in order to gain molecular insight into the structure, function, and species variation of TFIIIA ...

Debate and controversy exists concerning the potential for the herbicide atrazine to cause gonadal malformations in developing Xenopus laevis. Following review of the existing literature the U.S. Environmental Protection Agency required a rigorous investigation conducted under standardized procedures. X. laevis tadpoles were exposed to atrazine at concentrations of 0.01, 0.1, 1, 25, or 100 micr...

Despite intense study, the role of the immune system in detecting (immunosurveillance), controlling and remodeling (immunoediting) neoplasia remains elusive. We present here a comparative view of the complex interactions between neoplasia and the host immune system. We provide evidence, in the amphibian Xenopus laevis, consistent with an evolutionarily conserved and crucial role of the immune s...

In the haploid genome of Xenopus laevis there are two genes coding for the r-protein L14. It is not known if they are located on the same chromosome. cDNA clones deriving from the transcripts of the two genes have been isolated from an oocyte messenger cDNA bank showing that they are both expressed. We have studied the structure of one of the L14 genes by Electron Microscopy, restriction mappin...

Важливим завданням, без виконання якого неможливе розширення асортименту деревних рослин, що сприятиме збереженню їхнього біорізноманіття та раціональному використанню рослинних ресурсів, є встановлення їх репродуктивної здатності найоптимальніших методів розмноження. Наведено результати дослідження узагальнення роботи щодо особливостей вегетативного розмноження і вирощування садивного матеріал...