Parthenogenetic development of domestic cat oocytes treated with ionomycin, cycloheximide, roscovitine and strontium

Abstract

The objective was to evaluate the parthenogenetic activation of domestic cat oocytes. Cumulus-oocyte complexes matured for 36 h were subjected to three protocols of parthenogenetic activation: Group 1 - ionomycin + cycloheximide; Group 2 - ionomycin + roscovitine; and Group 3 - ionomycin + strontium. As a control, a fourth group of oocytes were cultured in the absence of any activation agent. In all groups, embryos were cultured in SOFaa for 72 h after activation and evaluated for activation rate, cleavage, and embryonic development using Hoechst33342. There were no significant differences among the three treated groups for rates of activated oocytes (70.1 +/- 4.3, 75.5 +/- 4.7, and 61.9 +/- 7.2%, for Treatments 1, 2, and 3 respectively; mean +/- SEM), or cleavage (48.1 +/- 5.9, 47.4 +/- 3.8, and 33.3 +/- 6.8%). However, activation and cleavage rates were higher (P < 0.05) than those in the control group (35.5 +/- 6.4 and 11.8 +/- 4.0%). There were no significant differences among treatment groups for proportion of embryos with 2-10 cells, 10-16 cells, and morulas. In the Control group, the embryo production rate was lower (P < 0.05), although the activation rate was high. The authors concluded that all three treatments effectively induced parthenogenetic activation of domestic cat oocytes. However, to optimize the use of strontium and roscovitine, a dose response and the effect of the presence of Ca(++) in the medium requires further study.

Farklı Aktivasyon Tekniklerinin Olgun Olmayan ve In Vitro Olgunlaştırılmış Kedi Oositleri Üzerine Etkisi

“…Although researchers [13] , reported satisfactory morula attainment results (22-25%) in CHX exposed cat oocytes, in our study the lowest morula-blastocyst rates were obtained in electrical stimulation and calcium ionophore groups exposed to CHX in both immature and matured oocyte groups (2.7-3.7%). These differences may depend on the use of different activator agents such as roscovitine, and strontium in the Rascadoa et al [13] study. In contrast, others demonstrated that aging oocytes undergo artificial activation more rapidly than oocytes matured for shorter (24 h) intervals [36] .…”

“…Several different activating stimulants such as ionomycin, ethanol or electrical pulses, protein synthesis inhibitors such as cycloheximide (CHX) and 6-(Dimethylamino) purine (6-DMAP) are widely used to induce the artificial activation of mammalian eggs [12] . CHX and 6-DMAP are the protein synthesis inhibitors responsible for decreasing MPF and MAPK activity of the oocyte and restarting meiosis [13] . Alternatively, the effect of electrical stimulation influences movement of calcium ions in the oocyte and ionomycin establishes a complex that transports calcium ions through the membrane and into the oocytes [7,8,14] .…”

“…Although, several publications on artificial activation of cat oocytes exist [10,14,29] , most of them are related to activation of MII stage oocytes during nuclear transfer studies. Only few studies had compared different methods of activation and their effectiveness, as measured by the number of activated oocytes and parthenogenetic embryos [7,13] . So far, a common activation method for cats has not been developed as the process is highly species specific.…”

Ovarian activity reversibility after the use of deslorelin acetate as a short-term contraceptive in domestic queens

“…Therefore, we inferred that this was due to spontaneous oocyte activation. In that regard, parthenogenesis in cats has been described, with a rate varying from 2 to 35.5% [24,25]. This is apparently the first report of oocyte recovery and viability after short-term contraceptive treatment with deslorelin acetate in domestic cats.…”

Developmental competence of cat (Felis domesticus) oocytes and embryos after parthenogenetic stimulation using different methods

“…The biotechnological methods of assisted reproduction in felids have been developed based on research into fertilization mechanisms and development of embryos in vitro . Cat embryos can be obtained in vitro by several methods: in vitro fertilization (IVF, ICSI) (Goodrowe et al , 1988; Johnston et al , 1989; Jewgenow et al , 1997; Pope et al , 1998; Ringleb et al , 2004), cloning (Shin et al ., 2002; Gómez et al , 2004) or artificial activation of oocytes (Grabiec et al , 2007; Rascado et al , 2010). In all of these methods, similar to IVF, activation of the oocyte is essential for triggering cleavage to form embryos.…”