Anchordoquy J P, Anchordoquy J M, Sirini M A, Mattioli G, Picco S J, Furnus C C
Instituto de Genética Veterinaria Prof. Fernando N. Dulout (IGEVET), Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, CONICET, La Plata, Argentina; Cátedra de Fisiología, Laboratorio de Nutrición Mineral, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, La Plata, Argentina.
Reprod Domest Anim. 2013 Dec;48(6):905-11. doi: 10.1111/rda.12184. Epub 2013 May 23.
Manganese (Mn) is a trace element present in forages and cereals, and its concentration depends on soil status. Manganese deficiency in cattle, goats and ewes not only impairs oestrous cycle but reduces calf birth weight. The achievement of the first oestrus is delayed, and more attempts are necessary to obtain a successful conception. This study was conducted to investigate the effect of the availability of supplemental Mn during IVM on DNA damage of cumulus cells and total glutathione (GSH) content in oocytes and cumulus cells. The effect of supplementary Mn during IVM on subsequent embryo development was also studied. The results reported here indicate (i) DNA damage in cumulus cells decreased with 0, 2, 5 and 6 ng/ml Mn supplementation during IVM (p < 0.05). (ii) Intracellular GSH-GSSG content increased (p < 0.01) with different Mn concentrations in oocytes and cumulus cells. Also, cumulus cell number per cumulus oocyte-complexes (COC) did not differ either before or after IVM. (iii) Addition of Mn to maturation medium resulted in similar cleavage rates (p > 0.05) at 0, 2, 5 and 6 ng/ml Mn. However, subsequent embryo development to blastocyst stage was significantly higher (p < 0.01) in oocytes matured with 5 and 6 ng/ml Mn. (iv) There was also an increase (p < 0.05) in mean cell number per blastocyst obtained from oocytes matured with 5 and 6 ng/ml respect to zero Mn (IVM alone) and 2 ng/ml Mn. This study provides evidence that optimal embryo development to the blastocyst stage was partially dependent on the presence of Mn during IVM. Moreover, the availability of Mn during oocyte maturation ensures 'normal' intracellular GSH content in COCs and protects DNA integrity of cumulus cells.
锰（Mn）是存在于草料和谷物中的一种微量元素，其含量取决于土壤状况。牛、山羊和母羊缺锰不仅会损害发情周期，还会降低犊牛出生体重。首次发情的时间会延迟，且需要更多次尝试才能成功受孕。本研究旨在调查体外成熟（IVM）期间补充锰的有效性对卵丘细胞DNA损伤以及卵母细胞和卵丘细胞中总谷胱甘肽（GSH）含量的影响。同时也研究了IVM期间补充锰对后续胚胎发育的影响。此处报告的结果表明：（i）IVM期间补充0、2、5和6 ng/ml锰可使卵丘细胞中的DNA损伤减少（p < 0.05）。（ii）卵母细胞和卵丘细胞中不同锰浓度下细胞内GSH-GSSG含量增加（p < 0.01）。此外，每个卵丘卵母细胞复合体（COC）的卵丘细胞数量在IVM前后没有差异。（iii）在成熟培养基中添加锰，0、2、5和6 ng/ml锰时的卵裂率相似（p > 0.05）。然而，用5和6 ng/ml锰成熟的卵母细胞随后发育到囊胚阶段的比例显著更高（p < 0.01）。（iv）与零锰（仅IVM）和2 ng/ml锰相比，用5和6 ng/ml锰成熟的卵母细胞所获得的每个囊胚的平均细胞数量也有所增加（p < 0.05）。本研究提供的证据表明，胚胎发育到囊胚阶段的最佳状态部分取决于IVM期间锰的存在。此外，卵母细胞成熟期间锰的有效性可确保COC中细胞内GSH含量“正常”，并保护卵丘细胞的DNA完整性。
