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Effect of Chemical or Electrical Activation of Bovine Oocytes on Blastocyst Development and Quality 总被引:2,自引:0,他引:2
MP Milazzotto WB Feitosa ARS Coutinho MD Goissis VP Oliveira MEOA Assumpção JA Visintin 《Reproduction in domestic animals》2008,43(3):319-322
Activation of in vitro‐matured (IVM) oocytes is essential for successful embryo production following nuclear transfer (NT) or intracytoplasmic sperm injection (ICSI). This study was designed to compare the rates of blastocyst production and embryo quality (as measured by numbers of viable cells) following parthenogenetic activation with electrical pulse or the use of two different calcium ionophores, A23187 (CA) or ionomycin (IO), with or without the addition of bovine serum albumin (BSA). IVM oocytes with a first polar body were randomly allocated to five treatment groups: CA (5 μm CA, 5 min; n = 88), CA + BSA (5 μm CA, 5 min; BSA, 5 min; n = 90), IO (5 μm IO, 5 min; n = 91), IO + BSA (5 μm IO, 5 min; BSA, 5 min; n = 86) and EL (two pulses of 1.5 kV/cm, 20 μs; n = 120). Blastocyst rates were higher (p < 0.05) for CA (54.4%), IO (51.4%) and EL (54.5%) than for IO + BSA (18.3%). Treatment CA + BSA (39.8%) did not differ from the others. There was no difference (p > 0.05) among treatments in total number of cells. However, the percentage of viable cells was reduced in CA (49.9%), CA + BSA (45.8%), IO (64.9%), IO + BSA (50.9%) compared with EL (82.7%). In summary, the addition of BSA to the IO treatment had an adverse effect on blastocyst production rates. Although there was no difference between electrical stimulation and chemical activation on blastocyst production rates, electrical activation resulted in blastocysts with a higher percentage of viable cells. 相似文献
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MJ Siemieniuch E Jursza MP Kowalewski M Majewska DJ Skarzynski 《Reproduction in domestic animals》2013,48(1):72-78
Sex steroids in synergy with prostaglandins (PG) are involved in the regulation of cyclic ovarian function. In this study, we investigated the mRNA expression of three genes involved in arachidonic acid (AA) metabolism and hence PG production in domestic cats: PG‐endoperoxide synthase (PTGS2), PGF2α synthase (PGFS) and PGE2 synthase (PGES). Feline endometria (n = 16) were collected at oestrus and mid and late phases of pseudopregnancy. In addition, the effects of E2 and/or P4 on PG secretion and gene expression on endometrial explants were studied in an in vitro culture system. Expression levels of all examined genes were up‐regulated at the mid phase of pseudopregnancy. The effects of E2 and/or P4 treatment on both PG secretion and expression of the genes were observed after 12 h of culture. Expression of PGES was significantly up‐regulated by E2 plus P4 at oestrus and the mid phase of pseudopregnancy and was also up‐regulated by a single treatment with P4 at late pseudopregnancy (p < 0.05). Simultaneous incubation with E2 and P4 up‐regulated PTGS2 gene expression at oestrus and mid‐luteal phase (p < 0.05). Progesterone plus E2 significantly increased PGE2 secretion at oestrus and the mid phase of pseudopregnancy. However, treatment with E2 and/or P4 affected neither PGF2α secretion nor PGFS expression at any phase after 12 h of culture. The overall findings indicate that genes involved in PG synthesis are up‐regulated at the mid phase of pseudopregnancy. An increase in PGE2 secretion and up‐regulation of PGES and PTGS2 are the main responses of the endometrium to treatment with E2 and P4 at oestrus and the mid phase of pseudopregnancy in the cat. These data support the hypothesis that ovarian sex steroids via endometrial PGE2 are involved in endocrine homoeostasis, especially at oestrus and the mid, but not the late, phase of pseudopregnancy in cats. 相似文献
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Objective To determine practices for control of louse infestation and blowfly strike in Queensland sheep flocks that are associated with organophosphorous and synthetic pyrethroid residues on wool.
Design Information on residues was obtained from a survey of Queensland wool clips. Information on pesticide use was obtained from a trace-back postal survey. The association between pesticide use and residues was assessed using generalised linear models, controlling for potential confounding by flock location.
Procedure Between 1995 and 1997 Queensland wool clips were randomly sampled. Samples were tested for the presence and amount (mg per kg of greasy wool) of organophosphorous and synthetic pyrethroid pesticides. A questionnaire seeking information on flock characteristics and pesticide use was sent to the manager of each flock from which a wool sample was tested.
Results The median amount of OP and SP residue was 0.8 and 0.25 mg/kg, respectively, and 91 and 95% of wool samples contained < 8 mg/kg of OP and SP residues, respectively. The frequency of OP pesticide use for louse control was significantly (P = 0.005) associated with mean OP residue amount, and the timing of SP use for louse control, in relation to shearing, was significantly (P < 0.001) associated with mean SP residue amount.
Conclusion Most Queensland wool clips have acceptable amounts of residues after the use of OP and SP pesticides, but wool growers can further reduce residues by effectively controlling louse infestation with pesticide applications early after shearing and the use of non-chemical methods of ectoparasite control. 相似文献
Design Information on residues was obtained from a survey of Queensland wool clips. Information on pesticide use was obtained from a trace-back postal survey. The association between pesticide use and residues was assessed using generalised linear models, controlling for potential confounding by flock location.
Procedure Between 1995 and 1997 Queensland wool clips were randomly sampled. Samples were tested for the presence and amount (mg per kg of greasy wool) of organophosphorous and synthetic pyrethroid pesticides. A questionnaire seeking information on flock characteristics and pesticide use was sent to the manager of each flock from which a wool sample was tested.
Results The median amount of OP and SP residue was 0.8 and 0.25 mg/kg, respectively, and 91 and 95% of wool samples contained < 8 mg/kg of OP and SP residues, respectively. The frequency of OP pesticide use for louse control was significantly (P = 0.005) associated with mean OP residue amount, and the timing of SP use for louse control, in relation to shearing, was significantly (P < 0.001) associated with mean SP residue amount.
Conclusion Most Queensland wool clips have acceptable amounts of residues after the use of OP and SP pesticides, but wool growers can further reduce residues by effectively controlling louse infestation with pesticide applications early after shearing and the use of non-chemical methods of ectoparasite control. 相似文献
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The -purpose of this paper is to examine mainly the role of energy intake on early embryo development. It has been shown that reduced energy intake can alter follicle growth patterns whereby follicle size is reduced and animals will have more waves of follicle growth throughout the cycle. In addition several studies have shown that high concentrate intake prior to or during superovulation will lead to reduced follicular growth and poorer embryo quality in beef heifers. In addition embryos recovered from animals on lower intakes have a better capacity to develop in short term culture in vitro. With a model using ovum pickup and in vitro maturation, fertilization and culture, it has not been possible to demonstrate clearly if the nutritional damage occurs prior to or after fertilization. 相似文献