L-Carnitine improves in vitro maturation of feline oocytes and subsequent development of embryos generated by parthenogenesis

Abstract EN

The objective of the current study was to assess the effect of L-Carnitine as a stimulant of lipid catabolism in vitro maturation (IVM) and in vitro culture (IVC) media on IVM rate (nuclear maturation) and embryonic development.

A total of 495 oocytes were assigned into two groups; the control group, oocytes matured in TCM-199 medium; L-Carnitine group oocytes matured in TCM-199 medium supplemented with L-Carnitine (0.5mg/ml).

After that 250 oocytes were stained with Hoechst 33342 then with Nile Red dye.

The nuclear maturation and oocyte lipid content were determined under a fluorescence microscope.

The other matured oocytes were parthenogentically activated using Thimerosal and DL- Dithiothreitol (DDT).

Presumptive zygotes were incubated in vitro culture 1 and 2, embryonic development was evaluated for morula and blastocyst stages.

The Metaphase II rates were 16.2% and 42.1% in the control group and L-carnitine group, respectively.

Overall, 9.3% and 14.9% of the oocytes reached at least the MI stage in the control group and L-carnitine group respectively.

The addition of L-carnitine in IVM media resulted in a significant decrease in the amount of lipid in cat oocyte.

Moreover, the incubation of matured oocytes in the L-carnitine group in IVC1 lead to significant increase in cleaved cells 29.4% in comparison with the control group 15.4%.

The incubation of cleaved cell of the L-carnitine group in IVC2 lead to decrease significantly in degenerated cells 12.5 % compared to the control group 42.9% while caused an increase significantly in morula 50% compared to the control group 33.3% and blastocyst 37.5% comparison with the control group 23.8%.

In conclusion, the use of L-Carnitine as a supplement in IVM media decrease lipid content of cat oocyte and subsequent enhance the nuclear and cytoplasmic maturation as demonstrated by increased parthenogentic development.-