Here, we discuss the role of conserved developmental timing processes in vertebrate hematopoiesis, highlighting how identification and manipulation of stage-specific factors that specify HSC developmental state must be harnessed to engineer HSCs for therapy.
The overlap between these different vertebrate species suggests not only that the general pattern of activity is conserved, but also that the timing of the roles of individual genes in development is conserved.
Recent studies have demonstrated cross talk between the miR156 and miR172 pathways, which appear to have conserved roles in coordinating the timing of vegetative phase changes and competency to flower in all angiosperms [ 11].
Although localization of early and late replication domains is not identical in different cell types (Hiratani et al. 2008; Schwaiger et al. 2009), the replication timing is remarkably conserved between distant species such as human and mouse (Yaffe et al. 2010).
let-7 microRNAs are evolutionarily conserved heterochronic genes that regulate developmental timing (Pasquinelli et al., 2000) and aging (Shen et al., 2012) in Caenorhabditis elegans.
Evolutionarily conserved monitoring mechanisms regulate the proper timing of events during cytokinesis progression (Agromayor and Martin-Serrano, 2013; Mierzwa and Gerlich, 2014).
Axonal growth cones navigate to their target over large distances with a precision and timing that is highly conserved from animal to animal.
A mean replication timing score of 5,810 genes conserved in the human genome is 1.4 compared with 0.5 for 7,713 nonconserved genes (P = 5.4E-146, Wilcoxon rank sum test).
However, exactly matched datasets are difficult to gather, and such an approach relies on the assumption that the precise timing of expression change should be conserved.
However, these results rest on the assumption that the timing of expression of embryonic genes is conserved across the entire phylogeny of the D. melanogaster group.
