In the transformants this condition likely results from a transgene position effect causing a silencing of some germination-specific genes. Finally, although amino acid activation of macroconidia of the two histidine transformants is a special case, this observation was extended to microconidia - another type of asexual vegetative spores produced by N. crassa whose germination has been very low or erratic. The finding that certain amino acids markedly improve the plating efficiency of microconidia of N. crassa is being reported separately. We thank Shahana Sultana for her help in some experiments. All media contained inositol.
Colonies appearing on histidine supplemented medium is taken as the number of viable macroconidia.
Each value is average of at least three experiments, each with three replicate platings. Each value is average of three experiments, each with three replicates. Thr 0.147 0.100 0.124 0.279 0.596 0.438 Ser 0.207 0.150 0.179 0.358 0.891 0.625 Glu 0.692 0.202 0.449 0.761 1.584 1.173 Pro 0.201 0.056 0.129 0.195 0.398 0.297 Gly 0.939 0.514 0.727 0.865 1.736 1.301 Cys 0.089 0.038 0.064 0.025 n.d.