Contribution of ITS towards identifying mites of the family Macrochelidae (Acari: Mesostigmata) collected from cattle manure in São Paulo, Brazil.

The aim of this study was to analyse morphological and molecular (ITS region) characteristics for eight species of mites in the family Macrochelidae that are present in cattle manure in Brazil. Six of these species were already known in Brazil and, for five of these, both tools (morphology and phylogeny) were concordant regarding all the trees used. The species G. saprophila and M. scutatus were reported in the present study for the first time in Brazil. The data obtained in this study suggest that the molecular analysis corroborated the morphological identification in most species of macrochelids. The results also demonstrate the need to correlate identifications through dichotomous keys, by using phylogenetic studies to better distinguish cryptic species.

Leptospiral TlyC is an extracellular matrix-binding protein and does not present hemolysin activity.

The role of TlyA, TlyB and TlyC proteins in the biology of Leptospira is still uncertain. Although these proteins have been considered as putative hemolysins, we demonstrate that leptospiral recombinant TlyB and TlyC do not possess hemolytic activity. However, further experiments showed that TlyC is a surface-exposed protein that seems to bind to laminin, collagen IV and fibronectin. The expression of both proteins was detected both in vitro and in vivo. Our findings suggest that TlyB and TlyC are not directly involved in hemolysis, and that TlyC may contribute to Leptospira binding to extracellular matrix (ECM) during host infection.

The P450 oxidoreductase, RedA, controls development beyond the mound stage in Dictyostelium discoideum.

BACKGROUND: NADPH-cytochrome-P450 oxidoreductase (CPR) is a ubiquitous enzyme that belongs to a family of diflavin oxidoreductases and is required for activity of the microsomal cytochrome-P450 monooxygenase system. CPR gene-disruption experiments have demonstrated that absence of this enzyme causes developmental defects both in mouse and insect. RESULTS: Annotation of the sequenced genome of D. discoideum revealed the presence of three genes (redA, redB and redC) that encode putative members of the diflavin oxidoreductase protein family. redA transcripts are present during growth and early development but then decline, reaching undetectable levels after the mound stage. redB transcripts are present in the same levels during growth and development while redC expression was detected only in vegetative growing cells. We isolated a mutant strain of Dictyostelium discoideum following restriction enzyme-mediated integration (REMI) mutagenesis in which redA was disrupted. This mutant develops only to the mound stage and accumulates a bright yellow pigment. The mound-arrest phenotype is cell-autonomous suggesting that the defect occurs within the cells rather than in intercellular signaling. CONCLUSION: The developmental arrest due to disruption of redA implicates CPR in the metabolism of compounds that control cell differentiation.