Amphibian parasites of the Order Dermocystida (Ichthyosporea) are widespread pathogens known mainly from Europe and North America, which cause primarily a disease of skin and subcutaneous tissue in their hosts. The taxonomy of these organisms has been problematic given their conserved morphology, similar clinical disease and pathology. Currently recognized taxa belong to the three closely related genera, Amphibiocystidium, Amphibiothecum, and Rhinosporidium, whereas species of Dermocystidium and Sphaerothecum destruens include fish parasites. Here, we review the taxonomy of Dermocystida based on a molecular phylogenetic analysis, principally of amphibian parasites, including DNA sequences obtained from amphibian hosts collected in the central-eastern region of South America. A new taxonomic arrangement is proposed, which includes the designation of type material for Dermocystidium pusula, synonymization of Amphibiothecum with Dermocystidium, and the restriction of Amphibiocystidium to its type species A. ranae. We also review the taxonomic status of Dermosporidium hylarum until the present work included in the synonymy of the human and animal pathogen R. seeberi, and considered herein as a valid taxon, however. In addition, a new species of Sphaerothecum parasitic to amphibians is described, being the first record of this genus in the southern hemisphere and in an amphibian host.

Melanophryniscus orejasmirandai is a species of toad known only from two localities in southern Uruguay. This toad isthe southernmost suggested taxon of the M. tumifrons group, whose species are characterized by a glandular frontal swell-ing on the snout. The study of the type series of M. orejasmirandai and of M. pachyrhynus, along with observations madeon many specimens of both species suggested a close relationship between them. The analysis of the variation of snout-vent length, coloration pattern, relative size of the frontal swelling, and presence/absence of the metatarsal gland showedthat characters previously used to separate both species resulted of no diagnostic value. Further comparison of the externalmorphology, osteological characters, and partial sequences of the cytochrome b gene indicated that M. orejasmirandai isa junior synonym of M. pachyrhynus. Melanophryniscus pachyrhynus is characterized by a reticulated orange ventral pat-tern which is shared only with M. peritus, from which it differs by its smaller size. The ornamentation of the nasal bonesunderlying the frontal swelling in M. pachyrhynus seems to be characteristic of the M. tumifrons group. An updated distribution map of M. pachyrhynus and some new localities are also provided.

The cultivation of genetically modified (GM) Bt maize (Zea mays L.) events MON810 and Bt11 is permitted in Uruguay. Local regulations specify that 10% of the crop should be a non-GM cultivar as refuge area for biodiversity, and the distance from other non-GM maize crops should be more than 250 m in order to avoid crosspollination. However, the degree of cross-fertilization between maize crops in Uruguay is unknown. The level of adventitious presence of GM material in non-GM crops is a relevant issue for organic farming, in situ conservation of genetic resources and seed production. In the research reported here, the occurrence and frequency of cross-fertilization between commercial GM and non-GM maize crops in Uruguay was assessed. The methodology comprised field sampling and detection using DAS-ELISA and PCR. Five field-pair cases where GM maize crops were grown near non-GM maize crops were identified. These cases had the potential to cross-fertilize considering the distance between crops and the similarity of the sowing dates. Adventitious presence of GM material in the offspring of non-GM crops was found in three of the five cases. Adventitious presence of event MON810 or Bt11 in non-GM maize, which were distinguished using specific primers, matched the events in the putative sources of transgenic pollen. Percentages of transgenic seedlings in the offspring of the non-GM crops were estimated as 0.56%, 0.83% and 0.13% for three sampling sites with distances of respectively 40, 100 and 330 m from the GM crops. This is a first indication that adventitious presence of transgenes in non-GM maize crops will occur in Uruguay if isolation by distance and/or time is not provided. These findings contribute to the evaluation of the applicability of the "regulated coexistence policy" in Uruguay.

In this paper we examine a new distance-based method for identifying and characterizing possible interactions between biological structures and objects, with respect to the initial developmental stages of Echinococcus granulosus . By adopting the surface of the foramen as the distance reference, several interesting results have been identified, including the fact that the cell nuclei tend to be organized with respect to the foramen surface as well as the stability of the spatial distribution of these nuclei along the development stages.

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