細(xì)胞競(jìng)爭(zhēng)是一個(gè)動(dòng)態(tài)平衡機(jī)制,，最先在果蠅中被觀察到，在這個(gè)過程中,，能夠存活,、但并不是最佳的細(xì)胞被從后生動(dòng)物的組織中清除掉。它的生物功能尚不清楚,，但現(xiàn)在Miguel Torres及其同事首次演示了哺乳動(dòng)物組織中正在發(fā)生的這一現(xiàn)象,，并且提出了它有可能發(fā)揮的一個(gè)功能。作者采用一種活體遺傳方法在小鼠外胚層（含有生成整個(gè)胚胎的多能干細(xì)胞的胚胎組織）中生成了Myc蛋白的“馬賽克”表達(dá),。他們發(fā)現(xiàn),，細(xì)胞競(jìng)爭(zhēng)受到相鄰細(xì)胞間在Myc劑量上天然出現(xiàn)的一個(gè)不平衡的促進(jìn)，同時(shí)他們也演示了通過凋亡來清除Myc水平相對(duì)較低的細(xì)胞,。這些發(fā)現(xiàn)說明細(xì)胞競(jìng)爭(zhēng)在外胚層干細(xì)胞池的優(yōu)化中扮演一個(gè)角色。本期封面所示為對(duì)細(xì)胞競(jìng)爭(zhēng)水平（從左向右）正在加劇的胚胎中的細(xì)胞類群的變化所做的熒光檢測(cè),。（生物谷 Bioon.com）
生物谷推薦的英文摘要
Nature doi:10.1038/nature12389
Myc-driven endogenous cell competition in the early mammalian embryo
Cristina Clavería Giovanna Giovinazzo Rocío Sierra Miguel Torres
The epiblast is the mammalian embryonic tissue that contains the pluripotent stem cells that generate the whole embryo. We have established a method for inducing functional genetic mosaics in the mouse. Using this system, here we show that induction of a mosaic imbalance of Myc expression in the epiblast provokes the expansion of cells with higher Myc levels through the apoptotic elimination of cells with lower levels, without disrupting development. In contrast, homogeneous shifts in Myc levels did not affect epiblast cell viability, indicating that the observed competition results from comparison of relative Myc levels between epiblast cells. During normal development we found that Myc levels are intrinsically heterogeneous among epiblast cells, and that endogenous cell competition refines the epiblast cell population through the elimination of cells with low relative Myc levels. These results show that natural cell competition in the early mammalian embryo contributes to the selection of the epiblast cell pool.
