Cryopreservation of immature bovine oocytes with 1,2 propanediol

O objetivo deste trabalho foi avaliar o efeito de dois gradientes de concentrações de 1,2 propanediol (PROH) na criopreservação de ovócitos imaturos, envoltos em células do cumulus, de bovinos abatidos em matadouro. No tratamento 1, com uso de 1,6 M de PROH, os ovócitos foram desidratados em três etapas crescentes (0,53; 1,06 e 1,6 M), à temperatura ambiente e congelados em nitrogênio líquido. A descongelação foi realizada em água a 37ºC por 30 segundos e a reidratação em três etapas decrescentes (1,6; 1,06 e 0,53 M), acrescidos de 0,25 M de sacarose cada. No tratamento 2 foi utilizado 2,0 M de PROH, de maneira semelhante ao tratamento 1, com desidratação contendo 0,7; 1,4 e 2,0 M, e reidratação 2,0; 1,4 e 0,7 M. Após a reidratação, os ovócitos foram lavados em meio TCM 199 (Meio de Cultivo para Tecidos) e levados para maturação in vitro. O grupo controle foi constituído de ovócitos recém-colhidos. Os ovócitos foram colocados para maturar por 24 horas, em meio TCM 199 com 10% de SVC (Soro de Vaca em Cio) e FSH (Hormônio Estimulante de Folículo), em co-cultura com células da granulosa, com 5% CO2 no ar a 39ºC. Os resultados de maturação nuclear foram diferentes (P<0,05) entre os ovócitos criopreservados e controle, sendo 2,04%, 0% e 84% para o tratamento 1, 2 e controle, respectivamente.A study was carried out to investigate the ability of immature bovine cumulus-oocytes complexes to survive cryopreservation and undergo subsequent in vitro maturation in two different levels of propanediol (PROH). Treatment 1 consisted of subjecting oocytes to a gradual 3-step, concentration-driven dehydration with PROH (0.53; 1.06 and 1.6 M) at room temperature and subsequent freezing. Oocytes were thawed in water at 37ºC for 30 seconds and subjected to a gradual 3-step, concentration-driven rehydration with PROH (1.6; 1.06 and 0.53 M) in the presence of 0.25 M sucrose. Treatment 2 was conducted the same way, but PROH concentrations for dehydration were 0.7; 1.4 and 2.0 M and for rehydration were 2.0; 1.4 and 0.7 M. After rehydration, oocytes of both treatments were washed in TCM 199 medium followed by the in vitro maturation. The control consisted of nonfrozen oocytes. Oocytes of all groups were cultured in TCM 199 medium with 10% ECS and FSH, and 5% CO2 air in co-culture at 39ºC, for 24 hours. The in vitro maturation rate of cryopreserved oocytes were different for treatments and control. Metafase II was reached by 2.04%, 0% and 84% for treatment 1, 2 and control, respectively

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Relative expression of mRNAs related to cavitation process in bovine embryos produced in vivo and in vitro

The objectives of this work were to identify and to evaluate possible differences on gene expression of aquaporins and Na/K-ATPases transcripts between embryos in vivo and in vitro produced. For each group, 15 blastocysts distributed in three pools were used for RNA extraction followed by amplification and reverse transcription. The resulting cDNAs were submitted to Real-Time PCR, using the GAPDH gene as endogenous control. It was not possible to identify AQP1 transcripts. Relative expression of AQP3 (1.33 ± 0.78) and AQP11 (2.00 ± 1.42) were not different in blastocysts in vitro and in vivo produced. Na/K-ATPase &#945;1 gene (2.25 ± 1.07) was overregulated whereas Na/K-ATPase &#946;2 transcripts 0.40 ± 0.30) did not differ among blastocysts produced in vitro from those produced in vivo. Transcripts for gene AQP1 are not present in bovine blastocysts. In vitro culture system does not alter expression of genes AQP3, AQP11 and Na/K-ATPase &#946;2 genes, however, it affects expression of Na/K-ATPase &#945;1