AD 2016 Q1

RESEARCH, EDUCATION & MEDICINE
EXPERT OPINIONS
the creation of proteins that build body structures and
control body functions — the individual’s observable
traits, called the phenotype.
This expression involves transcription of the code
from genes to messenger molecules that leave the
cell nuclei and enter the cell body, where they direct
synthesis of a specific protein. Gene expression is
affected by another layer of molecules (the epigenome),
which varies from cell to cell. The relationship between
genotype and phenotype is complicated further by
gene interaction with the environment. Thus, studying
genetics is complex and requires a lot of resources.
So far, genetic studies in diving have just scratched
the surface.
Changes in gene expression and transcription have
been found in animals exposed to breath-hold and
compressed-gas diving. Underwater diving exposes
divers to hyperoxia and increased production of
reactive oxygen species, which are involved with
nearly every physiological process in cells, including
programmed cell death (apoptosis). Response to this
stress alone can alter gene expression and transcription.
Similar stress may be caused by exercise in nondivers
and by many other factors.
Some studies found that experienced divers, as
compared with nondivers, showed persistent changes
in pathways of apoptosis, inflammation and immune
responses in blood transcriptomes, indicating a
cellular state of sustained alertness toward exogenous
stress. There were no measurable physiological
differences, however, between the divers and nondivers.
Changes found after scuba diving were typical of
sublethal oxidative stress; they included suppression
of lymphocyte activity and activation of the innate
immune system. It was not possible to distinguish the
effects of oxidative stress and of gas microbubbles.
Changes were similar after additional dives, and they
returned to normal in between the dives.
Whether there will be a dive analog of BRCA1 and
BRCA2 is impossible to predict at this stage. But
these are just the first steps in a long journey, and
accelerating development in medicine and technology
leaves little doubt that precision medicine for divers will
be achieved. AD
54 | WINTER 2016