Overexpression of S-adenosylmethionine decarboxylase (SAMDC) activates the maternal program of apoptosis shortly after MBT in Xenopus embryos.
Overexpression of S-adenosylmethionine decarboxylase (SAMDC) activates the maternal program of apoptosis shortly after MBT in Xenopus embryos.
复制标题
在爪蟾胚胎中，MBT 后不久，S-腺苷甲硫氨酸脱羧酶 (SAMDC) 的过度表达会激活母体细胞凋亡程序。
DOI：
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发表时间：
2000
影响因子：
0.7
通讯作者：
K. Shiokawa
中科院分区：
文献类型：
--
作者：
M. Kai;T. Higo;J. Yokoska;C. Kaito;E. Kajita;H. Fukamachi;E. Takayama;K. Igarashi;K. Shiokawa
S-腺苷蛋氨酸脱羧酶基因在非洲爪哇1-细胞期和2-细胞期过表达，导致囊胚晚期细胞自主解体和原肠胚早期发育停滞。在SAMDC过表达的细胞中，细胞解离的诱导发生在囊胚期的晚期，与显微注射SAMDC mRNA的阶段无关。当我们检查经历分离的细胞时，我们发现它们是TUNEL阳性的，含有浓缩的染色质的碎裂核和碎裂的DNA。此外，我们还将SAMDC基因和Bcl2基因一起注射到非洲爪哇的胚胎中，结果表明SAMDC基因的高表达胚胎可以被Bcl2完全挽救，并成为胚胎的蝌蚪。这些结果表明，SAMDC过表达导致的细胞解离与细胞死亡有关。由于SAMDC高表达胚胎中S-腺苷甲硫氨酸(SAM)水平显著降低，从而导致蛋白质合成受到抑制，并伴随着核酸和核糖核酸合成的抑制，我们得出结论：SAMDC过表达导致SAM缺陷，激活了非洲爪哇胚胎母体的细胞凋亡程序，但不是在胚泡发育后期。我们认为，这一机制可以作为一种监测机制来检查和消除卵裂阶段生理上受损的细胞。
Overexpression of S-adenosylmethionine decarboxylase (SAMDC) mRNA in 1- and 2-cell stage Xenopus embryos induces cell autonomous dissociation at the late blastula stage and developmental arrest at the early gastrula stage. The induction of cell dissociation took place "punctually" at the late blastula stage in the SAMDC-overexpressing cells, irrespective of the stage of the microinjection of SAMDC mRNA. When we examined the cells undergoing the dissociation, we found that they were TUNEL-positive and contained fragmented nuclei with condensed chromatin and fragmented DNA. Furthermore, by injecting Xenopus Bcl-2 mRNA together with SAMDC mRNA, we showed that SAMDC-overexpressing embryos are rescued completely by Bcl-2 and becometadpoles. These results indicatethat cell dissociation induced by SAMDC overexpression is due to apoptotic cell death. Since the level of S-adenosylmethionine (SAM) is greatly reduced in SAMDC-overexpressing embryos and this induces inhibition of protein synthesis accompanied by the inhibition of DNA and RNA syntheses, we conclude that deficiency in SAM induced by SAMDC overexpression activates the maternal program of apoptosis in Xenopus embryos at the late blastula stage, but not before. We propose that this mechanism serves as a surveillance mechanism to check and eliminate cells physiologically damaged during the cleavage stage.
非洲爪蟾原肠胚形成早期发育调节的细胞凋亡激活导致细胞周期间期细胞周期蛋白 A 降解。
DOI：
10.1242/dev.124.16.3185
发表时间：
1997
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Stack,JH;Newport,JW
通讯作者：
Newport,JW