We chose this locus as our main model system, because it is the simplest scrambled gene whose assembly requires all three types of DNA rearrangements, including deletion, inversion, and permutation, or segment reordering [37].
Although it has been noted that the social amoeba Dictyostelium discoideum, the main model system for amoeboid migration, can sense and align with grooves on agar, contact guidance during amoeboid migration has yet to be quantified or even studied systematically.
The molecular mechanisms underlying substrate-induced endocytosis of nutrient transporters have been studied in great detail in yeast, with Gap1 serving as the main model system (Jauniaux and Grenson 1990; Lauwers et al. 2010; Magasanik and Kaiser 2002; Chen and Kaiser 2002) (Fig. 2a).
Because it has multiple C3 and C4 species, more known C3-C4 intermediate species than any other genera, and is relatively young (past 5 to 10 million years), the genus Flaveria has become the main model system for the study of C4 evolution in the eudicots [ 10, 19].
The main insect model system Drosophila melanogaster lacks systemic RNAi and is therefore not well suited to screen for RNAi target genes [ 17].
The zebrafish has been established as the main vertebrate model system for whole organism screening applications.
Because of the established high incidence of male HS in sheep, this species is currently being used as the main neurophysiological model system to determine how sexually dimorphic nuclei in the brain become sex-reversed in homosexuals (reviewed in 17).
The main model for such a system already operates in the European Union, which has called on all industrialized countries to have systems in place by 2015 and for rapidly emerging economies like China and India to adopt them by 2020.
Consequently, the main limiting factor for developing model systems for evolutionary genomics is acquisition not of genomic resources but rather of sufficient evolutionarily relevant phenotypic and fitness data.
