A gag gene equipped in the preexisting element is likely to have been substituted by a presently unidentified host gene with the unusual motif during the evolutionary start point of CsRn1-like elements.
Considering the well-conserved, α-helix-rich secondary structure (Additional file 2) and the active replication of these elements including CsRn1 [ 26], the proteins seem to have nucleic acid-binding capacity to form VLPs. Malik and Eickbush [ 7] have proposed the chimeric origin of LTR retrotransposons and retroviruses, between a preexisting element and non-LTR element/host gene.
Several Presocratics formulated, in response, philosophical systems in which change is not considered to require something coming into being from complete nonexistence, but rather the arrangement of preexisting elements into new combinations.
A striking example of pattern mimicry is found in the pattern diversity of moth and butterfly wings, which is thought to evolve from preexisting elements illustrated by the nymphalid ground plan (NGP).
In site planning, a primary function of architectural design, the architect aims to create harmonies with preexisting elements in the landscape and "townscape".
By analogy with what astronomers presently observe to happen in regions of star formation, it is thought that the solar system began as a cloud of gas and dust comprising such preexisting elements.
Solé et al. note that use of preexisting elements in complex networks could act as strong constraints on evolution.
Among other aspects, the discovery of angiogenesis, the growth of new blood vessels from preexisting vasculature, as a key element in the pathogenesis of malignancy(7) has opened an abundance of biologic insights and subsequent therapeutic options, which have led to improved prognosis in many cancers including those originating from colon, lung, breast, and kidney.
Damage and failure phenomena on the cable system elements, produced by preexisting corrosion phenomena or unexpected failure mechanisms, are analyzed by using stationary or time dependent explicit laws, developed in the framework of the Continuum Damage Mechanics theory.
Similarly, in a comprehensive study of the immunoglobulin heavy-chain locus [ 6] (and many other loci), the multitude of preexisting loops and connecting regulatory elements are rearranged to form new ones that interact upon activation.
Integration of a selectable marker and template flanked by P-ends would generate a mutagenic precursor for TGC without the need for a preexisting P-element.
