Figure 3.

Developmental regulation of the survival motor neuron complex activity in the spinal cord. The graph shows the relative levels of small nuclear ribonucleoprotein (snRNP) assembly activity during spinal cord development. Spinal cords were isolated from embryos at embryonic day 18 (E18) as well as from mice at the indicated postnatal ages, SMN activity was then analysed in snRNP assembly experiments with in vitro-transcribed radioactive U1 snRNA and tissue extracts normalized for equal SMN content (Gabanella et al, 2005). The levels of U1 snRNP assembled in these reactions were quantified and expressed as a percentage of that of embryos at E18 arbitrarily set as 100%. d, day; SMN, survival motor neuron; w, week.