Kumar Dharmendra, Sarkhel Bikash Chandra
Animal Biotechnology Centre, Nanaji Deshmukh Veterinary Science University, Jabalpur, M.P., India.
Animal Biotechnology Centre, Nanaji Deshmukh Veterinary Science University, Jabalpur, M.P., India.
Gene Expr Patterns. 2017 Nov;25-26:118-123. doi: 10.1016/j.gep.2017.06.011. Epub 2017 Jun 29.
The success of Somatic cell nuclear transfer (SCNT) primarily depends on the extent of reprogramming of donor cells genome. The error of reprogramming may lead to inappropriate expression of embryonic genes at any stage of development. Under the present study the relative expression of different genes related to pluripotency (Oct-4 and Nanog), growth factors (IGF-2 and IGF-2R) and DNA methyltransferase gene (Dnmt-1) was evaluated in SCNT embryos at 8-16 cells, morula and blastocyst stages as compared to IVF group. In SCNT, significantly higher degree of relative expression was observed for Oct-4 in morula (1.41) and blastocysts (1.14) as compared to 8-16 cells (referral stage) whereas in IVF, a lower expression was observed at morula (0.82) stage. The expression of Nanog in SCNT embryos was increased significantly in morula (2.23) and decreased subsequently in blastocyst (0.56), whereas it was increased significantly from 8 to 16 cells to morula (1.62) and blastocyst (4.5) of IVF group. The IGF-2 and IGF-2R showed significantly higher expression rates in morula and blastocysts of SCNT (6.56, 5.90 and 1.11, 1.4) and IVF (8.69, 8.25 and 2.96, 3.91) embryos, respectively as compared to referral stage. The expression of Dnmt-1 was significantly higher in SCNT morula (1.29) and blastocyst (1.15) however in IVF, it was similar in 8-16 cells stage and morula but, higher in blastocyst (1.58). The dissimilar pattern of gene expression of SCNT might be a consequence of incomplete reprogramming of donor nucleus which resulted into lower blastocyst rate of SCNT as compared to IVF embryos.
体细胞核移植（SCNT）的成功主要取决于供体细胞基因组的重编程程度。重编程错误可能导致胚胎基因在发育的任何阶段出现不适当的表达。在本研究中，与体外受精（IVF）组相比，评估了SCNT胚胎在8 - 16细胞、桑葚胚和囊胚阶段与多能性相关的不同基因（Oct - 4和Nanog）、生长因子（IGF - 2和IGF - 2R）以及DNA甲基转移酶基因（Dnmt - 1）的相对表达。在SCNT中，与8 - 16细胞（对照阶段）相比，桑葚胚（1.41）和囊胚（1.14）阶段的Oct - 4相对表达程度显著更高，而在IVF中，桑葚胚（0.82）阶段的表达较低。SCNT胚胎中Nanog的表达在桑葚胚（2.23）时显著增加，随后在囊胚（0.56）时降低，而IVF组从8 - 16细胞到桑葚胚（1.62）和囊胚（4.5）时其表达显著增加。与对照阶段相比，IGF - 2和IGF - 2R在SCNT胚胎的桑葚胚和囊胚阶段（分别为6.56、5.90和1.11、1.4）以及IVF胚胎的桑葚胚和囊胚阶段（分别为8.69、8.25和2.96、3.91）显示出显著更高的表达率。Dnmt - 1在SCNT桑葚胚（1.29）和囊胚（1.15）中的表达显著更高，然而在IVF中，其在8 - 16细胞阶段和桑葚胚中相似，但在囊胚（1.58）中更高。SCNT基因表达的不同模式可能是供体细胞核重编程不完全的结果，这导致与IVF胚胎相比，SCNT的囊胚率较低。
