Research progress on methylation of histones H3K9 and H3K27 in early-stage embryos / 中华医学遗传学杂志

With the in-depth exploration of all stages in early-stage embryos, in particular zygotic genome activation and first cell lineage differentiation, researchers have found that early embryonic epigenetics follows a strict pattern of temporal and spatial modification. Previous studies have determined the inhibitory effect of H3K9me3 and H3K27me3 on genomic expression, and found that they are involved in many core biological events in the genome such as chromatin reprogramming, genomic imprinting, maintenance of embryonic stem cell pluripotency and somatic cell nuclear transfer, though the detailed molecular mechanism has remained elusive. From the point of developmental biology and epigenetics, this article has expounded the research progress on the methylation of H3K9 and H3K27 histones in early-stage embryos, which may provide a clue for the complex mechanism of embryonic development and improvement of culture method for embryos in vitro.

Screening and characterization of aptamers of human chronic myeloid leukemia (CML) fusion protein BCR-ABL and its structure analysis / 中国免疫学杂志

Objective:To screen and characterize aptamers against BCR-ABL fusion protein.Methods:A 90bp single stranded DNA( ssDNA) random library was subjected to 13 rounds of selection against BCR-ABL fusion protein by systematic evolution of ligands by expotential enrichment ( SELEX ) method, the selected aptamers were cloned and sequenced.The primary sequences and structure of aptamers were analyzed by Clustal W and DNA Folding Sever and the percentage of the ssDNA pool bound to BCR-ABL core protein were determinated.Results: after 13 rounds selection, the percentage of ssDNA pool bound to BCR-ABL fusion protein increased from 0.3%to 47.1%,the results showed that affinities of the Aptamers were different,the second structure analysis revealed possible stem-loops for binding to BCR-ABL fusion protein,the affinity of aptamer A2 to BCR-ABL fusion protein was highest with Kd values as low as 72 nmol/L.Conclusion:Aptamers against BCR-ABL fusion protein has been identified by SELEX methods from a 90 bp single stranded DNA library.And provide certain reference for the clinical treatment of chronic myelogenous.