Evolution, Molecular

An association between aging/longevity and cancer has long been suggested, yet the evolutionary and molecular links between these complicated traits remain elusive. Here, we analyze the relationship between longevity- and cancer-associated genes/proteins (LAGs/LAPs and CAGs/CAPs, respectively). Specifically, we address the following questions: (1) to what extent the CAGs and LAGs are evolutionary conserved and how they (or their orthologs) are related to each other in diverse species?

To identify new genetic regulators of cellular aging and senescence, we performed genome-wide comparative RNA profiling with selected human cellular model systems, reflecting replicative senescence, stress-induced premature senescence, and distinct other forms of cellular aging. Gene expression profiles were measured, analyzed, and entered into a newly generated database referred to as the GiSAO database.

Lifespan experiments of lower organisms and mammals along with recent studies of centenarians are making inroads into delineating genetic factors that determine the ability to achieve exceptional longevity. These models may be helpful for the discovery of both longevity-enabling genes as well as genes associated with increased propensity to develop specific diseases.

In animals, longevity (maximal lifespan) is inversely related to mass-specific basal metabolic rates. However, contrary to expectation, in several mammalian taxa, exceptional longevity is associated with high basal metabolic rate, and also fast evolution of mtDNA-coded proteins. The association of these traits was suggested to result from adaptive selection of mutations in mtDNA-coded proteins, which accelerates basal respiration, thus inhibiting the generation of reactive oxygen species that constrain longevity.

Insertions or deletions (indels) of amino acids residues have been recognized as an important source of genetic and structural divergence between paralogous Bcl-2 family members. However, these signature sequences have not so far been extensively investigated amongst orthologous Bcl-2 family proteins. Bcl2l10 is an antiapoptotic member of the Bcl-2 family that has evolved rapidly throughout the vertebrate lineage and which shows conserved abundant expression in eggs and oocytes.

Removal of the reproductive system of many animals including fish, flies, nematodes, mice and humans can increase lifespan through mechanisms largely unknown. The abrogation of the germline in Caenorhabditis elegans increases longevity by 60% due to a signal emitted from the somatic gonad. Apart from increased longevity, germline-less C. elegans is also resistant to other environmental stressors such as feeding on bacterial pathogens.

Although there is general agreement that most forms of common disease develop as a consequence of a combination of factors, including genetic, environmental and behavioural contributors, the actual mechanistic basis of how these factors initiate or promote diabetes, cancer, neurodegenerative and cardiovascular diseases in some individuals but not in others with seemingly identical risk factor profiles, is not clearly understood.

Drosophila nasuta nasuta (2n = 8) and D. n. albomicans (2n = 6) are morphologically identical, cross fertile and karyotypically dissimilar pair of chromosomal races belonging to nasuta subgroup of immigrans group of Drosophila. Interracial hybridization between these two races yielded karyotypically stabilized newly evolved Cytoraces with new combinations of chromosomes and DNA content, and are called nasuta-albomicans complex of Drosophila.

Human TDP-43 represents the main component of neuronal inclusions found in patients with neurodegenerative diseases, especially frontotemporal lobar degeneration and amyotrophic lateral sclerosis. In vitro and in vivo studies have shown that the TAR DNA-binding protein 43 (TDP-43) Drosophila ortholog (TBPH) can biochemically and functionally overlap the properties of the human factor.

The aging process is evolutionarily conserved and subject to quantitative modification by both genetic and environmental factors. Fundamental mechanisms of aging result in progressive deficits in the function of cells and organs, often leading to diseases that ultimately kill the organism such as cancers, cardiovascular disease and neurodegenerative disorders. Oxidative stress and damage to all of the major classes of molecules in cells are involved in aging and age-related diseases.