Simian virus 40 (SV40) early pre-mRNA is spliced using either of two alternative 5' splice sites and a common 3' splice site to produce two mRNAs that encode the T and t antigens. We have studied alternative splicing of SV40 early pre-mRNA in vitro using a HeLa cell nuclear extract. Synthetic SV40 early transcripts are processed to T and t antigen mRNAs in vitro. As in SV40-infected cells in vi...

Late Neoproterozoic-Early Cambrian schists have been occurred in southwest of Zanjan city from the Soltanieh belt. The Soltanieh belt in northwest of Iran is uplifted basement of Precambrian-Paleozoic in main central Iran zone and includes outcrops of Precambrian, Paleozoic and Mesozoic Formations. Late Neoproterozoic-Early Cambrian schists, the oldest stratigraphy unit in the region, consist o...

INTRODUCTION HLA-G is a major histocompatibility complex (MHC), class Ib molecule that is selectively expressed at the fetal-maternal interface. It is thought to play a role in protecting the fetus from the maternal immune response. Interestingly, the preimplantation embryo development (Ped) gene product Qa-2 is also a mouse MHC class Ib protein that affects cleavage and division of preimplanta...

In cleaving eggs of the newt, Cynops pyrrhogaster, the behaviour of the egg surface was analysed by observing linear and area changes in a transplanted piece of cortex which differed in pigmentation from the background. Results from the animal hemisphere showed that the surface in the cleavage plane shrank extensively in the region where the early cleavage furrow was being formed. On both sides...

Transcription of tRNA and mRNA occurs in quail as early as during cleavage while rRNA transcription becomes measurable during blastulation. The polyadenylated fraction content is newly synthesized RNA amounting to 6% during cleavage and blastulation decreases to 3% during gastrulation. Up to 3/4 adenylic residues incorporated into RNA during cleavage are accumulated in the polyadenylated molecu...

Cancer Diagnostics In article number 2200784, Kun Qian, Jiayi Wang, and co-workers develop a versatile electrochemical biosensing system for circulating miRNA detection by DNAzyme cleavage cycling amplification hybridization chain reaction amplification. By profiling in non-small-cell lung cancer cohort, this designed liquid biopsy strategy shows high efficiency sensitivity early diagnosis prog...

introduction: the value of embryonic stem-like cells in cloning is obvious. production of cloned animals can be achieved by introduction of these cells into a tetraploid embryo. tetraploid embryo is used as a feeder for development of embryonic stem-like cells and can be produced in vitro by electro-fusion of 2-cell embryos. the aim of this study was to ass,essthe effect of voltage alteration a...

To complete the cell cycle, the cleavage furrow draws the plasma membrane toward the cell center, pinching the cytoplasm into two lobes that are subsequently separated into two cells. The position of the cleavage furrow is induced by the mitotic spindle during early anaphase. Although the mechanism of cleavage furrow positioning is not understood at a molecular level, recent results suggest tha...

During early cleavages of Sicyonia ingentis embryos, mitotic spindle orientations differ between blastomeres and change in a predictable manner with each successive mitosis. From 2nd through 7th cleavages, spindles orient at a 90 degrees angle with respect to the spindle of the parent blastomere. Thus, spindle orientation is parallel to the cleavage plane that formed the blastomere. To determin...

Most of the small ribozymes, including those that have been investigated as potential therapeutic agents, appear to be rather poor catalysts. These RNAs use an internal phosphoester transfer mechanism to catalyze site-specific RNA cleavage with apparent cleavage rate constants typically <2 min(-1). We have identified variants of one of these, the Neurospora Varkud satellite ribozyme, that self-...