The initiation of mammalian embryonic transcription: to begin at the beginning

A temporal extracellular transcriptome atlas of human pre-implantation development

“…The time of human zygotic genome activation remains debatable. 4 , 7 More generally, many molecular events marking the human maternal-zygotic transition and their precise timing remain to be characterized. This work reveals a transition from oocyte to zygote in their extracellular exRNAs ( Figure 1 F).…”

“…These data are more compatible with the notion that zygotic genome activation is initiated at the 1-cell stage in humans. 4 , 7 …”

“… 1 , 2 The maternally deposited RNA must be present and depleted at specific developmental stages, and the zygotic genes must also be activated and repressed in specific orders. 3 , 4 , 5 , 6 Human embryos express up to 12,000 genes at each major developmental stage and exhibit vast transcriptomic changes as the embryos develop, 7 , 8 , 9 , 10 suggesting human pre-implantation development also requires the coordinated expression of many genes. Gene expression data, however, are rarely used for evaluation of the proper development of human in vitro fertilized embryos, due to the invasive procedures required by transcriptomic characterization.…”

Dynamics of transcription is affected by oxygen tension and developmental speed during in vitro production of bovine embryos

“…Previous studies have already demonstrated that cells undergoing reprogramming and/or differentiation processes, such as embryonic stem cells and cancer cells, are capable of early activation of specific transcript groups. For instance, cancer cells initially increase the expression of genes related to glycolysis to mediate the Warburg effect (Feng & Levine, 2010; Perry et al., 2023). In some species, CL‐stage embryos activate transcription and pluripotency factors prior to EGA (Lee et al., 2013).…”

TMEM225 Is Essential for Sperm Maturation and Male Fertility by Modifying Protein Distribution of Sperm in Mice

“…The sperm are expelled from the seminiferous tubule, processed by the epididymis, and stored in the cauda epididymis; the maturation process is completed, and all indicators of healthy sperm should be present ( 5 ). Spermatids are highly specialized cells that are transcriptionally silent and therefore change only through the acquisition or loss of proteins ( 6 , 7 , 8 ). Several previous studies on sperm proteomics in the epididymis have shown that sperm maturation is closely related to protein changes ( 9 , 10 , 11 ).…”