RESUMO
Background: The intracytoplasmic sperm injection (ICSI) technique has low efficiency in cattle. This has mainly been attributed to the oocyte activation failure due to oocyte and/or sperm factors. Aim: Our aim was to evaluate the effect of conventional ICSI and Piezo-ICSI with bull or human sperm on bovine oocyte activation and embryo development and to assess its relationship with the phospholipase C zeta (PLCÉ) activity of both species. Methods: In vitro matured bovine oocytes were randomly divided into five groups and were fertilized as follows: conventional ICSI using bovine sperm with chemical activation (control), conventional ICSI using bovine sperm, Piezo-ICSI using bovine sperm, conventional ICSI using human sperm, and Piezo-ICSI using human sperm. PLCÉ activity was determined in bull and human sperm samples. Results: Within the groups using bull sperm, the oocytes fertilized by conventional ICSI had the lowest values of 2 pronuclei (PN) formation and cleavage, Piezo-ICSI increased both percentages and ICSI + chemical activation presented the highest 2 PN, cleavage, and blastocyst rates (p < 0.05). Within the groups using human sperm, the oocytes fertilized by Piezo-ICSI presented higher 2 PN and cleavage rates than those activated by conventional ICSI (p < 0.05). Piezo-ICSI with human sperm increased bovine oocyte activation as much as conventional ICSI + chemical activation with bovine sperm (p < 0.05). Higher values of PLCÉ activity were found in human sperm compared with bovine sperm (p < 0.05). Conclusion: Our results suggest that the higher stability of the bovine sperm in combination with its relatively low content of PLCÉ impairs bovine oocyte activation after ICSI.
Assuntos
Oócitos , Injeções de Esperma Intracitoplásmicas , Espermatozoides , Bovinos , Injeções de Esperma Intracitoplásmicas/veterinária , Masculino , Animais , Humanos , Oócitos/fisiologia , Espermatozoides/fisiologia , Feminino , Fosfoinositídeo Fosfolipase C/metabolismoRESUMO
Plant viral infections induce changes including gene expression and metabolic components. Identification of metabolites and microRNAs (miRNAs) differing in abundance along infection may provide a broad view of the pathways involved in signaling and defense that orchestrate and execute the response in plant-pathogen interactions. We used a systemic approach by applying both liquid and gas chromatography coupled to mass spectrometry to determine the relative level of metabolites across the viral infection, together with a miRs profiling using a micro-array based procedure. Systemic changes in metabolites were characterized by a biphasic response after infection. The first phase, detected at one dpi, evidenced the action of a systemic signal since no virus was detected systemically. Several of the metabolites increased at this stage were hormone-related. miRs profiling after infection also revealed a biphasic alteration, showing miRs alteration at 5 dpi where no virus was detected systemically and a late phase correlating with virus accumulation. Correlation analyses revealed a massive increase in the density of correlation networks after infection indicating a complex reprogramming of the regulatory pathways, either in response to the plant defense mechanism or to the virus infection itself. Our data propose the involvement of a systemic signaling on early miRs alteration.