In a recent issue of Science, the puzzle of how a large number of maternal mRNAs can be coordinately destroyed at the mid-blastula transition of early animal embryogenesis is solved. The mysterious agent is not a protein but rather a microRNA that is transcribed at this transition point.

Interpreting a morphogen gradient into a single stripe of gene-expression is a fundamental unit of patterning in early embryogenesis. From both experimental data and computational studies the feed-forward motifs stand out as minimal networks capable of this patterning function. Positive feedback within gene networks has been hypothesised to enhance the sharpness and precision of gene-expression...

During evolution, the mammalian brain massively expanded its size. However, the exact roles of distinct neural precursors, identified in the developing cortex during embryogenesis, for size expansion and surface folding (i.e., gyration) remain largely unknown. New findings by Nonaka-Kinoshita et al advance our understanding of embryonic neural precursor function by identifying cell type-selecti...

Incubation climate can significantly influence hatchability, chick quality, and later performance in poultry. One of the most important factors is the incubation temperature (Decuypere and Michels, 1992). Changes of only 1°C from the optimum have a major impact, for instance, on hatching results in turkeys (French, 1994), but the strength of this influence depends on the time frame used and the...

The developmental hourglass model has been used to describe the morphological transitions of related species throughout embryogenesis. Recently, quantifiable approaches combining transcriptomic and evolutionary information provided novel evidence for the presence of a phylotranscriptomic hourglass pattern across kingdoms. As its biological function is unknown it remains speculative whether this...

Despite its vector importance little attention is given to Aedes aegypti embryonic development. In this study, temperature influence on time course of Ae. aegypti larvae hatching and egg viability were evaluated. The dormancy state at the end of embryogenesis could be interrupted with a proper stimulus. Temperatures tested ranged between 12-36 degrees C; the maximum temperature limit is 35 degr...

Vertebrates exhibit evolutionarily conserved asymmetries in the pattern of internal organ placement that are essential for their normal physiological function. Left-right asymmetries in organ situs are dependent upon the formation of an intact left-right axis during embryogenesis. Recently many of the molecular components involved in the initiation and maintenance of the left-right axis have be...