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A variety of laboratory tests were developed to obtain more reliable results of sperm evaluation and increase the accuracy of sperm fertility predictions. These tests detected damage of sperm specific compartments or organelles, which cannot be detected in routine sperm analysis. The use of fluorescent probes and detection using fluorescent microscopy or flow cytometry is an important tool but a more precise and accurate laboratory test is needed. Propidium iodide and 6-carboxyfluorescein diacetate are used for evaluations of plasmatic membrane integrity. Fluorescein isothiocyanate, associated with conjugated lecithin Psium sativum or Arachis hypogaea, are used for evaluations of acrosome integrity. Two probes, MitoTracker or Rhodamine123, are generally used to measure the absence or presence of mitochondrial potential. However, a better option is 5,5'; 6,6' -tetrachloro -1,1'; 3,3' -tetraetilbenzimidazolil-carbocyanine (JC-1) dye, which assesses not only the presence of mitochondrial potential and distinguished spermatozoa with poorly and highly functional mitochondria. Two techniques, TUNEL or COMETA, and the Acridine Orange Test (AOT) dye are used to evaluate chromatin integrity. A fluorescence technique based on chlortetracycline (CTC) or Merocyanine 540 is used to estimate whether sperm pass by or through the capacitation process. This review focuses on the fluorescent probes that are most widely used to evaluate plasma membrane integrity, capacitation, acrosome integrity, chromatin integrity and mitochondrial potential. Key words: Fluorescence microscopy, sperm, cryopreservation ResumoDiversos testes laboratoriais têm sido desenvolvidos com o intuito de obter resultados confiáveis nas avaliações espermáticas, aumentando a qualidade e a confiabilidade do sêmen utilizado em técnicas de reprodução assistida. Esses testes têm permitido detectar danos em compartimentos e organelas específicas da célula espermática, que não são detectados nas análises de rotina. Dentre esses testes, o uso de sondas fluorescentes e sua detecção em microscópio de epifluorescência ou citometria de fluxo se tornaram ferramenta importante quando uma avaliação mais acurada é necessária. Para a avaliação da integridade de membrana plasmática, pode ser utilizado o iodeto de propídio, associado ao diacetato de 6-carboxifluoresceína. As avaliações de integridade acrossomal podem ser feitas através do isotiocianato de fluoresceína, associado às lecitinas conjugadas, como a Psium sativum ou Arachis hypogaea. O potencial mitocondrial pode ser avaliado quanto à ausência ou presença através da sonda Mitotracker ou Rodamina 123. Outra opção ainda melhor pode ser observada utilizando o corante iodeto de 5,5'; 6,6' -tetracloro -1,1'; 3,3' -tetraetilbenzimidazolil-carbocianina (JC-1), este corante avalia a presença do potencial mitocondrial e avalia quanto à classificação do grau. Para avaliar a integridade

The hG-CSF (human Granulocyte Colony-Stimulating Factor) is a growth and stimulation factor capable of inducing the proliferation of bone marrow cells, several types of leukocytes, among other hematopoietic tissue cells. hG-CSF is used in used to treat anomalies that reder a small number of circulating white blood cells, which may compromise the immune defenses of the affected person. For these reasons, the production of hG-CSF in a bioreactor system using the mammary gland of genetic modified animals is a possibility of adding value to the bovine genetic material and reducing the costs of hG-CSF production in pharmaceutical industry. In this study, we aimed the production of transgenic hG-CSF bovine through the lipofection of bovine primary fibroblasts with an hG-CSF expression cassette and cloning these fibroblasts by the somatic cell nuclear transfer (SCNT) technique. The bovine fibroblasts transfected with the hG-CSF cassette presented a stable insertion of this construct into their genome and were efficiently synchronized to G0/G1 cell cycle stage. The transgenic fibroblasts were cloned by SCNT and produced 103 transferred embryos and 2 pregnancies, one of which reached 7 months of gestation.

The present study aimed to determine whether cumulus cells (CC) biopsy, acquired before or after in vitro maturation (IVM), presents similar gene expression pattern and if would compromises oocyte quality. First, immature cumulus oocyte complexes (COCs) were distributed: (1) maturated in groups (control); (2) individually maturated, but not biopsied; (3) subjected to CC biopsy before maturation and individually matured; (4) individually matured and submitted to CC biopsy after maturation; (5) individually matured and CC biopsied before and after maturation. Secondly, candidate genes, described as potential markers of COCs quality, were quantified by RT-qPCR in CCs before and after IVM. After in vitro fertilization (IVF), zygotes were tracked and sorted regarding their developmental potential: fully developed to embryo, cleaved and arrested, and not-cleaved. The COC’s biopsy negatively affects embryo development (p < 0.05), blastocyst cell number (p < 0.05), and apoptotic cell ratio (p < 0.05), both before and after IVM. The PTGS2, LUM, ALCAM, FSHR, PGR, SERPINE2, HAS2, and PDRX3 genes were differentially expressed (p < 0.05) on matured CCs. Only PGR gene (p = 0.04) was under-expressed on matured CCs on Not-Cleaved group. The SERPINE2 gene was overexpressed (p = 0.01) in the Cleaved group on immature CCs. In summary, none of the selected gene studies can accurately predict COC’s fate after fertilization.

This study aimed to establish a protocol for in vitro embryo production using epididymal sperm (EP). Samples were obtained from ejaculated sperm (EJ) and the epididymis of 7 Gir bulls. First, the effect of heparin (+) on the viability, longevity (Experiment 1) and fertilization rates (Experiment 2) of the EP was evaluated. In experiment 2, a pool of EP and EJ sperm (n = 7) was coincubated with cumulus-oocyte complexes (COCs) for 0, 3, 6, 12 and 18 h, and the fertilization rate (FR) was evaluated. A third experiment was performed to test sperm treatments for IVP using the Percoll (P) or PureSperm (PS) gradients or a spTALP wash for sperm selection. Cleavage, blastocyst rate (BR) and embryo sex were evaluated. In experiment 4, embryos were produced using 6, 12, and 18 h of sperm-oocyte coincubation. The cleavage, BR, and total number and percentage of apoptotic cells were determined. Heparin affected EP viability, longevity and FR. After 6 h, 82% of the oocytes were fertilized in the EP+ group, a higher value (P<0.05) than that in the EJ (19%) and EP- (42%) groups. At 12 and 18 h, FR remained higher in the EP+ group, and a gradual increase in polyspermy was observed. The use of a P or PS gradient yielded a similar BR on D7 (54% and 52%), which was higher than the rate obtained using the washing method (37%). The embryos produced by EP and selected in a P or PS gradient resulted in a sex deviation in favor of male embryos (P>0.05). No differences (P>0.05) were observed among the groups that were coincubated for 6, 12 and 18 h with respect to embryo production, kinetics of development, total cell number and percentage of apoptotic cells. In conclusion, IVF time can be reduced to 6 h without affecting embryo production and quality. In addition, EP sperm selection can be performed by either a PS or P gradient.

The establishment of epigenetic marks during the reprogramming window is susceptible to environmental influences, and stimuli during this critical stage can cause altered DNA methylation in offspring. In a previous study, we found that low levels of sulphur and cobalt (low S/Co) in the diet offered to oocyte donors altered the DNA methylome of bovine embryos. However, due to the extensive epigenetic reprogramming that occurs during embryogenesis, we hypothesized that the different methylation regions (DMRs) identified in the blastocysts may not maintain in adulthood. Here, we aimed to characterize DMRs previously identified in embryos, in the blood and sperm of adult progenies of two groups of heifers (low S/Co and control). We used six bulls and characterized the DNA methylation levels of KDM2A, KDM5A, KMT2D, and DOT1L genes. Our results showed that all DMRs analysed in both groups and tissues were hypermethylated unlike that noticed in the embryonic methylome profiles. These results suggest that embryo DMRs were reprogrammed during the final stages of de novo methylation during embryogenesis or later in development. Therefore, due to the highly dynamic epigenetic state during early embryonic development, we suggest that is essential to validate the DMRs found in embryos in adult individuals.

To evaluate the addition of antioxidants in extenders on post-thaw bovine semen quality and in vitro embryo production effi ciency. Six semen samples were collected from fi ve Holstein bulls. In the experiment I, the samples were diluted with AndroMed® and Bovimix® and added antioxidants glutathione (1.5 and 2.5 mM) and melatonin (0.5 and 1.0 mM). In the experiment II, the best treatments obtained in experiment I were used for in vitro fecundation. Glutathione did not improve sperm viability. Melatonin had a negative effect on semen characteristics. Andromed® showed better results in sperm kinetics parameters. Bovimix® was more effi cient in maintaining cell integrity parameters. Signifi cant correlation was found between sperm kinetics parameters and between cell integrity parameters. For in vitro embryo production, after oocyte selection, maturation, fertilization and cultivation were performed using the four treatments previously evaluated. Andromed® was more effi cient in the cleavage rate, no effect of the addition of glutathione. However, the addition of 2.5 mM glutathione in the Bovimix® improved the cleavage rate. There was a signifi cant moderate correlation between cleavage rate and sperm kinetic characteristics. Glutathione did not improve sperm viability. Melatonin reduced the maintenance of sperm characteristics. Andromed® was more effi cient in in vitro embryo production and no effect of glutathione was found in this extender. Addition of 2.5 mM glutathione in the Bovimix® extender provided a higher cleavage rate.

A inseminação artificial (IA) é uma das biotécnicas mais utilizadas dentro da pecuária bovina. Embora a IA seja realizada sem a aplicação de hormônios exógenos, o uso do análogo do hormônio liberador de gonadotrofina (GnRH) imediatamente após a inseminação artificial tem sido proposto para otimizar os resultados das taxas de concepção com o uso da IA, uma vez que o análogo do GnRH estimula a hipófise para a liberação do hormônio folículo estimulante (FSH) e do hormônio luteinizante (LH). O objetivo deste trabalho foi avaliar o uso do análogo de GnRH em vacas leiteiras no momento da realização da IA. Para responder aos questionamentos propostos, o experimento teve início com a detecção do estro seguido de IA. No momento da IA foi realizada a aplicação do hormônio via endovenosa em 40 vacas, distribuídas em multíparas e primíparas. Para o grupo controle, 40 novilhas foram utilizadas sem tratamento hormonal. Os resultados obtidos mostraram que embora tenha sido feito o uso do análogo de GnRH, a taxa de concepção dos animais não foi alterada, sendo que o grupo controle apresentou maior taxa de concepção em comparação ao grupo tratado. De acordo com os resultados observados neste experimento, a aplicação do análogo de GnRH imediatamente após a realização da IA não apresenta eficácia no aumento das taxas de concepção em fêmeas bovinas multíparas ou primíparas.