A biotecnologia animal tem fornecido novas ferramentas para os programas de melhoramento e, dessa forma, contribuído para melhorar a eficiência da produção dos produtos de origem animal. No entanto, os avanços têm sido mais lentos do que antecipados, especialmente em razão da dificuldade na identificação dos genes responsáveis pelas características fenotípicas de interesse zootécnico. Três estratégias principais têm sido utilizadas para identificar esses genes - mapeamento de QTL, genes candidatos e sequenciamento de DNA e mRNA - e cada uma tem suas vantagens e limitações. O mapeamento de QTL permite determinar as regiões genômicas que contêm genes, mas o intervalo de confiança do QTL pode ser grande e conter muitos genes. A estratégia de genes candidatos é limitada por causa do conhecimento ainda restrito das funções de todos os genes. Os sequenciamentos de genomas e de sequências expressas podem auxiliar na identificação da posição de genes e de vias metabólicas associadas à característica de interesse. A integração dessas estratégias por meio do desenvolvimento de programas de bioinformática permitirá a identificação de novos genes de interesse zootécnico. Assim, os programas de melhoramento genético se beneficiarão pela inclusão da informação obtida diretamente do DNA na avaliação do mérito genético dos plantéis disponíveis.
Animal biotechnology is providing new tools for animal breeding and genetics and thus contributing to advances in production efficiency and quality of animal products. However, the progress is slower than anticipated, mainly because of the difficulty involved in identifying genes that control phenotypic characteristics of importance to the animal industry. Three main strategies: QTL mapping, candidate genes and DNA and mRNA sequencing have been used to identify genes of economic interest to animal breeding and each has advantages and disadvantages. QTL mapping allows identification of the genomic region that contains the genes, but the confidence interval of the regions is usually large and may contain several genes. Candidate gene approach is limited to our restricted knowledge of the biological function of the genes. Sequencing of genomes and expressed sequences tags can provide identifying gene position and metabolic pathways associated with phenotypic trait. Integrating these strategies using bioinformatics software will allow identifying of novel genes for animal production. Then, animal breeding programs will include the information from DNA directly on evaluation of genetic value of livestock production

The establishment of invading organisms in natural ecosystems is one of the most serious environmental issues. In Brazil, the invasive species Limnoperna fortunei (Dunker, 1857), the golden mussel, is a mollusk capable of causing major changes in water systems, generating social and economic impacts, given its biofouling capacity. Limnoperna fortunei can easily block pipes and heat exchangers in the water systems of hydroelectric power plants due to its ability to strongly adhere to the substrate using its byssus -a bundle of filaments secreted by these animals. Therefore, the early detection of this invader is essential for management actions to be immediate, in order to control population growth rate at the beginning of the invasive process, preventing this environment from serving as a source for new infestations. The implantation of a method that integrates the active monitoring of prioritized areas, laboratory techniques, including molecular biology methods, and the sharing of hydrographic data between basin managers and users for early detection of the presence of species in Brazilian waters appears as an efficient option to prevent and control invasions.

Electrospinning emerged as a promising technique to produce scaffolds for cultivated meat in function of its simplicity, versatility, cost-effectiveness, and scalability. Cellulose acetate (CA) is a biocompatible and low-cost material that support cell adhesion and proliferation. Here we investigated CA nanofibers, associated or not with a bioactive annatto extract (CA@A), a food-dye, as potential scaffolds for cultivated meat and muscle tissue engineering. The obtained CA nanofibers were evaluated concerning its physicochemical, morphological, mechanical and biological traits. UV-vis spectroscopy and contact angle measurements confirmed the annatto extract incorporation into the CA nanofibers and the surface wettability of both scaffolds, respectively. SEM images revealed that the scaffolds are porous, containing fibers with no specific alignment. Compared with the pure CA nanofibers, CA@A nanofibers showed increased fiber diameter (420 ± 212 nm vs. 284 ± 130 nm). Mechanical properties revealed that the annatto extract induces a reduction of the stiffness of the scaffold. Molecular analyses revealed that while CA scaffold favored C2C12 myoblast differentiation, the annatto-loaded CA scaffold favored a proliferative state of these cells. These results suggest that the combination of cellulose acetate fibers loaded with annatto extract may be an interesting economical alternative for support long-term muscle cells culture with potential application as scaffold for cultivated meat and muscle tissue engineering.

Identification and characterization of transcripts associated with skeletal muscle development and growth in chicken (Gallus gallus). A large improvement in skeletal muscle mass quantity in domestic animals was achieved by animal breeding programs along the years based on the observation of adult phenotypic characters. But, the number of myogenic precursor cells and, consequently, the number of muscle fibers is determined during the embryonic stages of development. Therefore, the embryonic myogenic program is an ideal target for searching potential candidate-transcripts, that can influence skeletal muscle deposition in domestic animals. This work aimed to identify original candidate-transcripts associated with skeletal muscle development and growth in chicken embryos (Gallus gallus). A total of previously identified 4,534 transcripts (Expressed Sequence Tags) were transferred to a nylon membrane (microarray) to investigate differences in expression patterns among genotypes and tissues. The pectoral skeletal muscle transcriptional pattern between broiler and layer chicken lines allowed the identification of 98 differentially expressed transcripts, whose expression were validated by quantitative RT-PCR (Reverse-transcription Polymerase Chain Reaction), and were co-localized in coincident regions with previously mapped QTLs (Quantitative Trait Loci). These transcripts are now preferential candidates to further identify mutations, and/or to develop specific markers to be used in breeding programs for early or indirect selection of superior animals. The same microarray was used to characterize unknown transcripts by expression patterns among five tissues (brain, heart, liver, muscle and skin). This approach allowed to identify tissue-specific and/or preferentially-expressed transcripts, and to characterize 24 unknown transcripts as co-expressed with skeletal musclespecific ones. Finally, the axon guidance molecule RGM-A, identified as skeletal muscle-specific transcript by microarrays, was selected to be functionally analyzed in vivo, to investigate the function of this atypical transcript in the skeletal muscle and to demonstrate the approach efficiency to guide selection of candidate transcripts. The RGM-A expression pattern and the Pax3 phenotype after over-expression in chicken embryos indicated a possible association of this axon guidance with the skeletal muscle formation. The candidate transcripts identified by mycroarray analyses may be useful in animal breeding programs to increase the present gains in chicken growth rate, since additional information is urgently required to surpass current limits of selection gains. The results have also opened a new range of possibilities to promote the functional characterization in vivo of unknown transcripts, having chicken embryos as models.

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Background Limnoperna fortunei is a bivalve mollusk originally from southern Asia that invaded South America in the 1990's. Its high efficiency in pumping and filtering water and the capacity to promote strong adhesion to different substrates allowed the adaptation of this invasive species, associated with several environmental and economic damages. A deep understanding of the biology and ecology aspects of L. fortunei is necessary to outline effective strategies to manage its invasion. Mollusk gills are important structures responsible for several biological functions including breathing and feeding. In this work, we characterized the ultrastructure of L. fortunei gills and its ciliary epithelium using transmission and scanning electron microscopy. This is the first report of the L. fortunei gills ciliary epithelial cells visualized with high resolution and detailed morphology. Results The analysis showed a highly organized and large amount of ciliary structures (frontal cilia, laterofrontal cilia, and lateral cilia) on the entire length of the branchial epithelium. Mitochondria, smooth endoplasmic reticulum and glycogen granules were abundantly found in the epithelial cells of the gills, suggesting that all this energetic apparatus could be related to the morpho-functional structure of the cilia. Vesicles possibly containing mucus could also be observed in these cells, suggesting that they might be related to L. fortunei mechanism of selection and/or rejection of captured particles suspended in water. Conclusions Our data suggest the mechanism used by this mollusk for particles capture and selection, which could contribute to a better understanding of important aspects of invasion and decide on more efficient and economic strategies of population control.

Background : Cell culture is an important tool in medical and biological research laboratories, supporting cell therapies and tissue bioengineering strategies. Gingival fibroblasts present structural function, being able to modulate their metabolic capacity, which is reflected in the tissue morphology. The possibility of culturing human fibroblasts in vitro, in monolayer or on three-dimensional scaffolds, for subsequent transplants in vivo opens important perspectives for the periodontal regeneration.Aim/Hypothesis : The objective is present a method to obtaining and culture of the viable human gingival fibroblasts for in vitro research Material and Methods : Explants derived from periodontal surgical discards were used, grown in 25 cm2 bottles to obtain a primary cell culture.After observing the proliferation and growth of the fibroblasts that interconnected and formed a monolayer network, involving the periphery of the explants, it was possible to remove the explants, to make the passage and the new subcultures were obtained in a ratio of 1-1. After 7 days, the amount of viable cells was analyzed in triplicate, using the Neubauer chamber technique, in cell culture bottles of 25 mm2 (T25) and 75 mm2 (T75). Fibroblasts were described and sub classified morphologically.Results : The results showed a growth pattern in both bottles, but with a larger number in bottles of 75 cm2. Cells with fibroblastic morphology were sub classified into reticular and fusiform, being predominant those with fusiform morphology. Conclusion and ClinicalImplications : Culture of the explant of human gingival connective tissue is a viable method for obtaining gingival connective tissue cells suitable for laboratory tests in cell culture, aiming at obtaining constructs for gingival tissue engineering.

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