In principle, sister-disorders might be expected to result in diametric phenotypes to the extent that genotype phenotype mappings are relatively simple functions of gene copy number and diametric alterations to developmental-genetic pathways; for example, Bi et al. (2007) reported hypoactivity versus hyperactivity in mice with the RAI1 gene experimentally deleted versus duplicated.
Genetic pathways for dark skin are different in Tamil Nadu an in Nigeria.
New data gathered by Global Wildlife Conservation and Panthera, in collaboration with Michigan State University, shows that two major genetic pathways for jaguars and other large mammals from Central America will be cut in two by the Nicaraguan Interoceanic Canal.
Further examination of the defects displayed by maternally and zygotically deprived Smr1 mutant embryos or larvae may reveal which other genetic and developmental pathways – for example, segmentation, neurogenesis, or myogenesis – are also subject to regulation by SMRTER during early embryonic development.
Instead, genetic variability of entire biological pathways, for example, the estrogen metabolism pathway, should be investigated to evaluate potential association with disease.
Nevertheless, it is also possible that obesity and bone area share common pathways (for example, genetic), such that an increase in one variable (for example, obesity) is paralleled by increases in the other (for example, bone size).
In addition, genetic studies show that variants associated with triglyceride-related pathways (for example the APOA5 variant 1131T>C), are associated with coronary risk [ 28].
Therefore, Breivik and Glaudernack's hypothesis for distinct carcinogens to exert their effect on two proposed types of genetic instability, i.e., microsatellite instability and chromosomal instability [ 16], may be extended to the potential effect of carcinogens on more specific genetic pathways to colorectal tumorigenesis, as for example the KRAS mutated pathway.
Additionally, as there is significant interaction between intracellular signalling pathways, further genetic aberrations affecting the PI3 kinase pathway, for example, may also be sufficient to induce melanoma development.
AD is a multi-factorial disorder [ 45, 46] involving a complex pathway(s) comprising both genetic (for example, APP, presenilin gene, apolipoprotein E gene, and γ-secretase activating protein gene) and epigenetic (inflammatory insults, and oxidation reactions) components.
These single-gene deletion and overexpression strains are a very powerful research tool for elucidating genetic pathways.
