Failure of sexing by developmental arrest of bovine embryos in vitro produced with H-Y antisera

Embriões bovinos produzidos in vitro, em estádio de mórula, foram cultivados em meio contendo anticorpos anti H-Y de alto título proveniente de ratos por 24h e, após este tempo, classificados em dois grupos: 1) embriões inibidos em estádio de mórula (classificados como machos) e 2) embriões que se desenvolveram e formaram a blastocele (classificados como fêmeas). O sexo de 311 embriões, distribuídos em três grupos de concentração dos anticorpos, 3%, 5% ou 7%, foi identificado pela reação em cadeia da polimerase. Não houve desvio da proporção entre machos e fêmeas (P>0,05) nos grupos em que se utilizaram os anticorpos anti H-Y, quando comparadas ao grupo-controle, sem adição de anticorpos anti H-Y. Diferentemente dos resultados obtidos utilizando-se embriões bovinos produzidos in vivo, a sexagem com anticorpos anti H-Y de alto título em embriões produzidos in vitro não propiciou sucesso.In vitro produced bovine embryos at morula stage were cultured in medium containing high titer of rat H-Y antisera for 24h. The embryos were classified in two groups: 1) embryos arrested at morula stage (classified as males); and 2) embryos that developed and formed a blastocoele (classified as female). The sex of 311 embryos, divided in three groups of concentration of H-Y antisera, 3%, 5% or 7%, was identified by polimerase chain reaction. The results showed no difference (P>0.05) on sexual deviation in groups in which the H-Y antisera was added, in relation to control group, in which no H-Y antisera was added. In contrast with results obtained with in vivo produced bovine embryos, the sexing of in vitro produced bovine embryos with high H-Y antisera titer did not succed.CNP

Sexagem de embriões bovinos fecundados in vitro pela técnica de PCR multiplex

Neste trabalho, a técnica de PCR ("polymerase chain reaction") foi utilizada para a sexagem de 92 embriões bovinos fertilizados in vitro. Os embriões originaram-se de fertilização in vitro de oócitos aspirados de ovários de fêmeas bovinas, provenientes de abatedouros comerciais. Os oócitos foram maturados, fertilizados e cultivados até o estádio de blastocisto. Os embriões foram lavados em solução de PBS, transferidos para tubos de polipropileno contendo água ultrapura, e imediatamente congelados a -196ºC. Os embriões foram descongelados sobre isopor contendo gelo picado e tratados com proteinase K. Para a reação de PCR, utilizaram-se alíquotas de 34 µl de cada tudo, onde foram acrescidos dois pares de primers, seqüência BC1.2 e seqüência satélite 1.715, desoxinucleotídeos, MgCl2, tampão PCR 10X, TaqDNA polimerase e água, em um volume final de 50 µl. As amostras foram amplificadas e a eletroforese realizada em gel de poliacrilamida a 8%. Os géis foram corados com solução de brometo de etídio e analisados em transiluminador de luz ultravioleta. Um índice de 93,47% de amplificação foi atingido, com 41 embriões (47,67%) machos e 45 (52,32%) embriões fêmeas. O uso de gel de poliacrilamida a 8% foi eficaz na separação de fragmentos de DNA muito próximos.In the present study the polymerase chain reaction (PCR) was used for sexing ninety-two in vitro fertilized bovine embryos. The embryos were obtained after in vitro fertilization of oocytes from slaughterhouses. The oocytes were matured, fertilized, and cultured until the blastocyst stage. The embryos were washed in PBS solution, and transferred to polypropylene tubes with containing ultrapure water and immediately frozen at -196ºC. The embryos were thawed on ice and treated with proteinase K. For the PCR reaction, aliquots of 34 µl from each tube were mixed to the primers BC1.2 and microsatellite sequence 1715, dNTPs, MgCl2, 10X PCR buffer, Taq DNA polymerase and water in a final volume of 50 µl. The samples were amplified and the PCR products separated by electrophoresis in a 8% polyacrylamide gel. The gels were stained in ethidium bromide solution and vizualized under UV-light. The amplification rate was 93.47%, with 41 (47.67%) male embryos and 45 (52.32%) female embryos. The use of 8% polyacrylamide gel was efficient for separating DNA fragments of very similar size

Transferrin and albumin polimorphism and its correlation with sexual maturity in bulls

O presente estudo utilizou 16 animais Bos taurus indicus da raça Nelore doadores de sêmen. Estes animais foram divididos em grupos de acordo com a idade em que o sêmen congelou pela primeira vez. O grupo I, considerado precoce, apresentou animais com sêmen passível de congelação com idade inferior a 20 meses. O grupo II, composto por animais que tiveram o sêmen congelado com idade entre 21 e 26 meses. E o grupo III, tido como tardio, composto por animais com sêmen congelável com idade superior a 27 meses. Para análise dos padrões eletroforéticos da transferrina e albumina, amostras de sangue foram colhidas em tubos heparinizados e submetidos a centrifugação de 2.500 G por 15 minutos para separação do plasma sangüíneo. As amostras de plasma sangüíneo foram processadas para que a corrida eletroforética em gel de poliacrilamida pudesse ser realizada. Para a coloração do gel, usou-se Coomasie Brilliant Blue. Após análise dos padrões eletroforéticos da transferrina e albumina, observou-se que não houve relação detectável entre os fenótipos da albumina e precocidade sexual de touros doadores. Entretanto, em relação à transferrina, foi possível sugerir uma associação entre o alelo TfD com touros portadores de sêmen congelável precocemente ou medianamente em termos de idade à congelação.The association between biochemical polymorphic systems and early sexual maturity was assessed subjecting 16 animals (from 17 to 36 months old) to eletrophoretic studies, searching for transferrin and albumin polymorphisms. Two albumin alleles, AlbA (AlbF) and AlbB (AlbS), but only either as AlbB homozigotes or AlbAB heterozigotes were observed. There were no AlbA homozigotes. It was not possible to detect relationships between albumin genotypes and early sexual maturity. Regarding transferrin, it was possible to detect two alleles (TfD and TfE). When trying to establish a relationship between transferrin electrophoretic pattern and the desirable economic trait (early sexual maturity) it is suggested that the TfD allele could be associated with bulls that probably will provide freezable semen at an early age

Effect of sequence of insemination after simultaneous thawing of multiple semen straws on conception rate to timed AI in suckled multiparous Nelore cows

The objective was to determine the effect of sequence of insemination after simultaneous thawing of multiple 0.5 mL semen straws on conception rate in suckled multiparous Nelore cows. The effect of this thawing procedure on in vitro sperm characteristics was also evaluated. All cows (N = 944) received the same timed AI protocol. Ten straws (0.5 mL) of frozen semen from the same batch were simultaneously thawed at 36 degrees C, for a minimum of 30 sec. One straw per cow was used for timed AI. Frozen semen from three Angus bulls was used. Timed AI records included sequence of insemination (first to tenth) and time of semen removal from thawing bath. For laboratory analyses, the same semen batches used in the field experiment were evaluated. Ten frozen straws from the same batch were thawed simultaneously in a thawing unit identical to that used in the field experiment. The following sperm characteristics were analyzed: sperm motility parameters, sperm thermal resistance, plasma and acrosomal membrane integrity, lipid peroxidation, chromatin structure, and sperm morphometry. Based on logistic regression, there were no significant effects of breeding group, body condition score, AI technician, and sire on conception rate, but there was an interaction between sire and straw group (P = 0.002). Semen from only one bull had decreased (P < 0.05) field fertility for the group of straws associated with the longest interval from thawing to AI. However, the results of the laboratory experiment were unable to explain the findings of the field experiment. Sperm width:length ratio of morphometric analysis was the single sperm characteristic with a significant interaction between sire and straw group (P = 0.02). It was concluded that sequence of insemination after simultaneous thawing of 10 semen straws can differently affect conception rates at timed AI, depending on the sire used. Nevertheless, the effects of this thawing environment on in vitro sperm characteristics, remain to be further investigated. (C) 2012 Elsevier Inc. All rights reserved.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

Transmission electron microscopy for characterization of acrosomal damage after Percoll gradient centrifugation of cryopreserved bovine spermatozoa

The objective of this study was to characterize acrosomal ultrastructure following discontinuous Percoll gradient centrifugation of cryopreserved bovine sperm. Semen was collected from six bulls of different breeds and three ejaculates per bull were evaluated. Frozen semen samples were thawed and the acrosomal region of sperm cells was evaluated by transmission electron microscopy (TEM) before (n = 18) and after (n = 18) Percoll centrifugation. The evaluation of 20 sperm heads from each of the 36 samples analyzed ensured that a large number of cells were investigated. The data were subjected to analysis of variance at a level of significance of 5%. Percoll centrifugation reduced the percentage of sperm exhibiting normal acrosomes (from 61.77 to 30.24%), reduced the percentage of sperm presenting atypical acrosome reactions (from 28.38 to 4.84%) and increased the percentage of sperm exhibiting damage in the acrosome (from 6.14 to 64.26%). The percentage of sperm with typical acrosome reactions was not significantly different before (3.70%) and after (0.67%) centrifugation. TEM distinguished four different types of acrosomal status and enabled ultrastructural characterization of acrosomal injuries. The percentage of sperm exhibiting normal acrosomes decreased and damage in the acrosome was the most frequent acrosomal injury with the Percoll gradient centrifugation protocol utilized

Predictors of healthy aging: epigenetic factors and the APOE gene

INTRODUÇÃO: Fatores genéticos estão associados a fenótipos do envelhecimento como a longevidade e algumas doenças relacionadas à idade, mas a identificação dos genes envolvidos no fenótipo complexo do envelhecimento permanece um desafio. Estudos de associação genômica ampla (GWAS), têm apontado o gene da Apolipoproteína E (APOE) como o único associado de maneira consistente à longevidade e alguns fenótipos do envelhecimento. Até o momento, entretanto, a associação do gene APOE com fenótipos alternativos como o envelhecimento saudável (ES), não tem sido demonstrada de maneira consistente. OBJETIVOS: determinar a influência do polimorfismo do APOE na variação de índices prognósticos do envelhecimento (multimorbidade, funcionalidade e acúmulo de déficits) em dez anos. MÉTODOS: estudo longitudinal de coorte retrospectiva de 125 idosos independentes inicialmente para atividades de vida diária (ABVD e AIVD), de um ambulatório assistencial em um hospital escola, em São Paulo. Na avaliação inicial, foram identificados o polimorfismo do gene APOE (alelos E2, E3 e E4), variável preditora primária, e algumas variáveis epigenéticas (clínicas, sociodemográficas e hábitos de vida). No seguimento, avaliações anuais de prontuários foram realizadas para identificar associações com perdas de envelhecimento fisiológico (índice de acúmulo de déficits, DI), ganho de multimorbidade (Cumulative Illness Rating Scale for Geriatrics, CIRS-G e Charlson comorbidity index, CCI) e dependência em ABVD/AIVD, e morte, em dez anos. Curvas de Kaplan-Meier e modelos de regressão de Cox foram utilizados para associações dos fatores genéticos e epigenéticos com piora funcional e morte, e de regressão linear múltipla para associações com os índices CIRS-G, CCI e DI. RESULTADOS: 125 participantes da avaliação inicial, idade média de 74,9 anos, 76,8% mulheres, e 81,6% brancos. A média do CIRS-G foi de 10,24. A distribuição dos alelos: E2 10%, E3 50,8%, e E4 39,2%. A presença de E2 e E4 em relação ao grupo controle E3/E3 não foram preditoras de piora nos índices prognósticos do envelhecimento. Alguns fatores epigenéticos apresentaram associações com desfechos em dez anos. Maior acúmulo de déficits: idade mais elevada p = 80 anos, sedentarismo e tabagismo). A idade >=80 anos, sexo masculino e sedentarismo, foram associados a perda em dez anos de funcionalidade para ABVD e AIVD. Atividades metabólicas e morar sozinho foram associados a menor multimorbidade em dez anos. Mortalidade em dez anos foi associada a idade >= 80 anos e alta multimorbidade através do CCIBACKGROUND: While genetic factors are linked to longevity and agerelated diseases, the identification of genes responsible for different aging phenotypes remains unclear. Previous studies, including the genome-wide association studies (GWAS), have indicated that Apolipoprotein E (APOE) gene is associated with longevity and other aging phenotypes. However, little is still known on the association of the APOE gene with healthy aging. OBJECTIVES: To determine the influence of the APOE gene polymorphism on the variation of aging prognostic indices (functionality, multimorbidity, and accumulation of deficits) over 10 years. METHODS: A retrospective cohort study comprising 125 older adults who were independent in activities of daily living (ADL and IADL) at baseline. Participants were evaluated at an ambulatory setting from an academical medical center at the University of Sao Paulo Medical School. Baseline assessment included the identification of the APOE gene polymorphism (alleles E2, E3, and E4), which was the primary predictor, and other epigenetic variables such as sociodemographic factors, multimorbidity, and behavior measures. Annual follow-up evaluations over 10 years were conducted to identify dependencies in ADL and IADL, multimorbidity, and death using the hospital medical charts. A cumulative deficit index was computed using the patients\" multimorbidity and functionality every year. Kaplan-Meier curves and Cox proportional hazard models were used to associate the genetic and epigenetic factors with time to dependence in ADL and IADL and death. Multiple linear regression models examined the association of risk factors with the scores of the Cumulative Illness Rating Scale for Geriatrics (CIRS-G), Charlson comorbidity index, and deficit index at 10 years. RESULTS: Participants had a mean age of 74.9 years; 76.8% were female, and 81.6% white. The mean score in CIRS-G was 10.2 points. The distribution of the alleles of APOE was 10% for E2, 50.8% E3, and 39.2% E4. Compared to the allele E3/E3 (control group), the presence of allele E2 did not predict dependence in ADL and IADL. The presence of allele E4 did not predict any outcome. Some epigenetic risk factors were associated with the outcomes over 10 years. For significant increase in deficit index: older age, p < 0,001; sedentarism, p=0,02; tobacco consumption p=0,02 .For dependence in ADL: older age, p=0.002; men p=0,01 ; higher scores in the CIRS-G, p=0.02; sedentarism, p=0.02. For dependence in IADL: older age, p < 0.001; men p=0,01 ; sedentarism, p=0.02 For mortality: older age, p=0,002; higher score in the Charlson comorbidity index, p=0.001. While metabolic activities (beta=-4,37; p=0.003) and living alone (beta=-2,28; p=0.005) were associated with a lower score in the CIRS-G at 10 years of follow-up, alcohol consumption (beta=1,78; p=0.04) was associated with higher scores in this index. CONCLUSIONS: The APOE gene polymorphism did not influence the prognosis of aging. Older age, sedentarism and tobacco consumption were associated with a significant increase in deficit index. Older age, men and sedentarism were predictors of functional loss. Metabolic activities and living alone were associated with a lower score in the CIRS-G at 10 years of follow-up. Older age and multimorbidity at baseline were predictors of mortalit