Expression of an X-linked HMG-lacZ transgene in mouse embryos: implication of chromosomal imprinting and lineage-specific X-chromosome activity.
Expression of an X-linked HMG-lacZ transgene in mouse embryos: implication of chromosomal imprinting and lineage-specific X-chromosome activity.
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X 连锁 HMG-lacZ 转基因在小鼠胚胎中的表达：染色体印记和谱系特异性 X 染色体活性的含义。
DOI：
10.1002/dvg.1020150608
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
S. Tan
中科院分区：
文献类型：
--
作者：
P. Tam;E. Williams;S. Tan
使用编码β-半乳糖苷酶（β-Gal）的X连锁lacZ转基因在细胞水平上研究了雌性小鼠胚胎中的X染色体活性。卵母细胞中母体RNA的翻译被视为持续到早期卵裂阶段的β-Gal活性。来自母体X染色体（Xm）的转基因的合子转录首先在约8细胞期发现。相比之下，在父方X染色体（Xp）上的lacZ转基因的表达直到16-32细胞期的后期才被看到。Xp的优先失活发生在壁性滋养外胚层、原始内胚层和极性滋养外胚层的衍生物中，但这些谱系中的少数细胞可能仍然保留有活性的父系X染色体。X失活开始于3.5天内的内细胞团，但与以前的研究结果相反，该过程并没有完成在胚胎外胚层的5.5至6.0天。在原肠胚形成期间，在胚胎外胚层中也观察到β-Gal活性的区域变化，这可能与细胞命运的规范有关。在所有体细胞组织中，Xp和Xm基因的随机失活，但该过程在不同组织中在不同时间完成。在脊索、心脏和胚胎肠道等组织中，X染色体失活的进展较慢，主要是由于这些组织中相当一部分细胞中持续维持着两条活性X染色体。关于内源性X连锁基因甲基化的最新发现表明，β-Gal的延长表达也可能是由于在不同组织中失活沿着X染色体向lacZ转基因位点的不同传播速率。
X-chromosome activity in female mouse embryos was studied at the cellular level using an X-linked lacZ transgene which encodes beta-galactosidase (beta-Gal). Translation of maternal RNA in oocytes is seen as beta-Gal activity that persists into early cleavage-stages. Zygotic transcription of the transgene from the maternal X chromosome (Xm) is first found at about the 8-cell stage. By contrast, expression of the lacZ transgene on the paternal X chromosome (Xp) is not seen until later at the 16-32-cell stage. Preferential inactivation of Xp occurs in the mural trophectoderm, the primitive endoderm, and derivatives of the polar trophectoderm, but a small number of cells in these lineages may still retain an active paternal X chromosome. X inactivation begins at 3.5 days in the inner cell mass but contrary to previous findings the process is not completed in the embryonic ectoderm by 5.5 to 6.0 days. Regional variation in beta-Gal activity is also observed in the embryonic ectoderm during gastrulation which may be related to the specification of cell fates. Random inactivation of Xp and Xm ensues in all somatic tissues but the process is completed at different times in different tissues. The slower progression of X inactivation in tissues such as the notochord, the heart, and the embryonic gut is primarily due to the persistent maintenance of two active X chromosomes in a significant fraction of cells in these tissues. Recent findings on the methylation of endogenous X-linked genes suggest that the prolonged expression of beta-Gal might also be due to the different rate of spreading of inactivation along the X chromosome to the lacZ transgene locus in different tissues.
转基因小鼠胚胎中父本 Pgk-1 表达的时间。
DOI：
10.1242/dev.111.4.1109
发表时间：
1991
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Pravtcheva,DD;Adra,CN;Ruddle,FH
通讯作者：
Ruddle,FH
X连锁人类胶原蛋白转基因可以避免部分细胞中X染色体失活。
DOI：
10.1242/dev.116.3.687
发表时间：
1992
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Wu,H;Fässler,R;Schnieke,A;Barker,D;Lee,KH;Chapman,V;Francke,U;Jaenisch,R
通讯作者：
Jaenisch,R
DOI：
10.1073/pnas.89.21.10469
发表时间：
1992-11-01
影响因子：
11.1
作者：
SINGERSAM, J;CHAPMAN, V;RIGGS, AD
通讯作者：
RIGGS, AD