Modak Avijit Kumar, Alam Md Hasanur, Islam Md Nuronnabi, Paul Nipa, Akter Ireen, Hashem Md Abul, Kabir Akm Ahsan, Moniruzzaman Mohammad
Department of Animal Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
Animals (Basel). 2022 Aug 2;12(15):1957. doi: 10.3390/ani12151957.
This study aimed to determine the effect of L-carnitine on the growth and subsequent nuclear maturation of buffalo small growing oocytes (92−108 µm in diameter) in vitro. Oocyte-granulosa cell complexes (OGCs) were dissected from early antral follicles of slaughtered buffaloes and cultured in in vitro growth (IVG) medium with the supplementation of different concentrations (0, 1.25, 1.875 or 2.5 mM) of L-carnitine for 6 days. The results revealed that L-carnitine increased the diameter of buffalo oocytes in vitro. The degeneration rate was significantly (p < 0.05) lower in 2.5 mM of L-carnitine-treated oocytes (10%) than others (55%, 45% and 32.5% in 0, 1.25 and 1.875 mM of L-carnitine-supplemented groups, respectively). The OGCs showed antrum-like structures significantly (p < 0.05) higher in the 2.5 mM of L-carnitine group (74.0%) than the 0- and 1.25-mM groups (34.6% and 38.1%, respectively). Furthermore, in vitro grown oocytes were placed in in vitro maturation (IVM) medium for 24 h to examine meiotic competence of in vitro grown oocytes with L-carnitine. The L-carnitine (1.875 and 2.5 mM) treated oocytes showed a higher rate of nuclear maturation up to the metaphase II (MII) stage and a lower rate of degeneration. In conclusion, L-carnitine enhances the growth, prevents degeneration, promotes the formation of antrum-like structures and supports nuclear maturation of buffalo oocytes in vitro.
本研究旨在确定左旋肉碱对水牛小生长卵泡卵母细胞（直径92 - 108 µm）体外生长及随后核成熟的影响。从屠宰水牛的早期窦状卵泡中分离出卵母细胞-颗粒细胞复合体（OGCs），并在添加不同浓度（0、1.25、1.875或2.5 mM）左旋肉碱的体外生长（IVG）培养基中培养6天。结果显示，左旋肉碱可增加水牛卵母细胞的体外直径。2.5 mM左旋肉碱处理的卵母细胞退变率（10%）显著低于其他组（0、1.25和1.875 mM左旋肉碱补充组分别为55%、45%和32.5%，p < 0.05）。2.5 mM左旋肉碱组的OGCs出现类似卵泡腔的结构比例（74.0%）显著高于0 mM和1.25 mM组（分别为34.6%和38.1%，p < 0.05）。此外，将体外生长的卵母细胞置于体外成熟（IVM）培养基中培养24小时，以检测左旋肉碱对体外生长卵母细胞减数分裂能力的影响。左旋肉碱（1.875和2.5 mM）处理的卵母细胞达到中期II（MII）期的核成熟率更高，退变率更低。总之，左旋肉碱可促进水牛卵母细胞体外生长，防止退变，促进类似卵泡腔结构的形成，并支持其核成熟。
