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The procedure of in-vitro fertilization (IVF) is sometime physically stressful and emotional turmoil on the couples undergoing treatment. The male partner is obliged to produce semen for injection/insemination with the oocytes. Unfortunately, some men are ill-fated, not capable to reproduce semen on the day of oocyte pickup.
During the past decade the need for Artificial Reproductive Techniques in felids has greatly increased. Mostly, this is a result of growing expectations that these techniques may be applied in conservation biology and thereby contribute to saving wild felids from extinction. In this article we describe three most common methods of obtaining embryos in vitro in the domestic cat and its wild relatives: classic in vitro fertilisation, in vitro fertilisation by intracytoplasmic sperm injection and somatic cell nuclear transfer. Each of the methods provides a cleavage rate of around 50% and approx. 20% of embryos develop to the blastocyst stage. After the transfer of embryos produced by these methods, scientists obtained living offspring of the domestic cat, as well as several wild cats: the tiger, serval, fishing cat, caracal, ocelot, wild cat, sand cat, black-footed cat and the oncilla. These successes, in spite of the low efficiency of the discussed methods, are promising and suggest that biotechniques of reproduction will be valuable tools in the protection of wild species. Somatic cell nuclear transfer will allow to sustain the narrow gene pool in the critically endangered felids. For these reasons it is necessary to conduct further research on the optimization of artificial reproduction techniques in cats.
The study investigated the effects of three different KH₂PO₄ concentrations (0.59 mM; 1.19 mM; 2.38 mM) in Whitten’s medium and co-culture on in vitro two-cell blocks and their development to the blastocyst stage of inbred BALB/C mice embryos following in vitro fertilization. Standard IVF and IVC procedures were used and mouse oviduct cells were used as a co-culture. The results demonstrated that various concentrations of potassium were not effective on the cleavage rates. 1.19 mM KH₂PO₄ with and without co-culture groups (P<0.05)had the highest rate of reaching the 4-to 6- and 8-cells. At the 72nd hour, the 1.19 mM KH₂PO₄ groups without (55.26%) and with co-culture (44.77%) (P<0.05) displayed the most satisfactory development to the morula stage. Although 0.59 mM and 2.38 mM KH₂PO₄ were found to be insufficient to develop up to morula, 0.59 mM KH₂PO₄ with co-culture may have beneficial effects (31.57%; P<0.05). On the other hand, despite the high concentration of KH₂PO₄ (16.90%) supporting a more effective development rate to the morula than the lower level (P<0.05), it was noted that co-cultures having a high KH₂PO₄ were not beneficial. KH₂PO₄ with and without (30.00%) co-culture (26.01%) (P<0.05) demonstrated the most beneficial development of the blastocyst stage.
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