The embryo non-invasive pre-implantation diagnosis era: how far are we?

Advancements in assisted reproduction (AR) methodologies have allowed significant improvements in live birth rates of women who otherwise would not be able to conceive. One of the tools that allowed this improvement is the possibility of embryo selection based on genetic status, performed via preimplantation genetic testing (PGT). Even though the widespread use of PGT from TE biopsy helped to decrease the interval from the beginning of the AR intervention to pregnancy, especially in older patients, in AR, there are still many concerns about the application of this invasive methodology in all cycles. Therefore, recently, researchers started to study the use of cell free DNA (cfDNA) released by the blastocyst in its culture medium to perform PGT, in a method called non-invasive PGT (niPGT). The development of a niPGT would bring the diagnostics power of conventional PGT, but with the advantage of being potentially less harmful to the embryo. Its implementation in clinical practice, however, is under heavy discussion since there are many unknowns about the technique, such as the origin of the cfDNA or if this genetic material is a true representative of the actual ploidy status of the embryo. Available data indicates that there is high correspondence between results observed in TE biopsies and the ones observed from cfDNA, but these results are still contradictory and highly debatable. In the present review, the advantages and disadvantages of niPGT are presented and discussed in relation to tradition TE biopsy-based PGT. Furthermore, there are also presented some other possible non-invasive tools that could be applied in the selection of the best embryo, such as quantification of other molecules as quality biomarkers, or the use artificial intelligence (AI) to identify the best embryos based on morphological and/or morphokitetic parameters.(AU)

Taxonomia e filogenia molecular de Myxozoa parasitas de peixes de água doce oriundos de ambiente natural e de sistema de criação / Taxonomy and molecular phylogeny of Myxozoa parasites of freshwater fish from natural environment and fish farm

O filo Myxozoa possui uma grande diversidade, sendo conhecidas cerca de 2300 espécies, as quais infectam principalmente peixes, mas também anfíbios répteis e aves. Para este estudo, coletas dos peixes de água doce foram realizadas no Pantanal Mato-grossense (estados de Mato Grosso e do Matogrosso do sul) e no Rio Mogi Guaçu e piscicultura do CEPTA/ICMBio (estado de São Paulo), visando estudos moleculares e morfológicos de mixosporídeos parasitas de 6 espécies de peixes. Os resultados das análises moleculares (amplificação e sequenciamento do gene 18S rDNA) e morfológicas revelaram a ocorrência de 11 espécies de mixosporídeos, sendo cinco parasitas comuns a Pseudoplatystoma corruscans e Pseudplatystoma fasciatum, três parasitas de Salminus brasiliensis, uma espécie parasita de Brycon hilarii, uma de Zungaru jahu e outra de Piaractus mesopotamicus. Das onze espécies, cinco ainda não são descritas pela literatura. A análise filogenética, utilizando o método de Neighbor-Joining, mostrou que o agrupamento das espécies ocorre principalmente de acordo com a proximidade filogenética de seus hospedeiros e que todas as espécies da América do Sul agruparam em um clado monofilético. Foi observado, em alguns pontos da árvore filogenética, que o tropismo de tecido e/ou órgão de infecção caracteriza um importante fator de seleção evolutiva. Com menor frequência também foi observado alguns agrupamentos resultantes de parasitas cuja maior relação aparente era a sua localização geográfica, porém, novos estudos ainda são necessários para determinar o verdadeiro papel deste fator na evolução dos mixosporídeos

The phylum Myxozoa has a great diversity, with about 2300 known species, which infect mainly fishes, but also amphibians, reptiles and birds. In this study, freshwater fishes were caught in the Brazilian Pantanal wetland (Mato Grosso and Mato Grosso do Sul states) and in the Mogi Guaçu River and CEPTA/ICMBio\'s fishfarm (São Paulo state) aiming the molecular and morphological studies of myxosporeans parasites of 6 fish species. The results of molecular (amplification and sequencing of the 18S rDNA gene) and morphological analysis revealed the occurrence of 11 species of myxosporeans, five of them infecting both Pseudoplatystoma corruscans and Pseudoplatystoma fasciatum, three parasites of Salminus brasiliensis, one specie infecting Brycon hilarii, one infecting Zungaro jahu and another infecting Piaractus mesopotamicus. Of these eleven species, five are not yet described by literature. The phylogenetic analysis, using the Neighbor-joining method, showed that the species clustered mainly according to the phylogenetic distance of their hosts and that all species of South America were grouped in a monophyletic clade. In some positions of the phylogenetic tree was observed that tissue tropism and/or organ of infection characterized an important factor in evolutionary selection. Less frequently was also observed some groups containing species which the major apparent relation is its geographical position, however, new studies are still needed to determine the true role of this factor in the evolution of myxosporeans