|
Centenarian
Species and Rockfish Project: John C. Guerin,
Director 8205 SW 46th
Ave. Portland, OR
97219 (503) 975-4915 jguerin@agelessanimals.org
[John C. Guerin
C.V.]
Extending the Healthy Lifespan of Humans: the Essence is
Negligible Senescence General:
AgelessAnimals.org is a
research effort started in 1995 by Director John C. Guerin. The
project's focus is understanding how long-lived animals are so
successful at retarding aging, and applying this knowledge to extend
the healthy lifespan of humans. These animals include rockfish,
turtles and whales, all documented to live 200 years or longer
without showing signs of aging.
The project's research is now
uncovering the mechanisms that allow continued vitality in these
long-lived animals. With that knowledge it will help us understand
why humans are healthy for many years, but then start having more
and more age-related problems. Because of our aging population, the
research will have enormous benefits for humanity, not only in
greater health and enjoyment of later years, but in controlling the
escalating costs of Social Security and medical care.
Only a few projects in the world
study long-lived animals. AgelessAnimals reports the latest research
to both general and gerontological audiences. Current research from
14 pilot studies, located at twelve universities around the
United States and
two in Europe, encompass topics
from Free-radical damage to DNA Micro-array gene
expression.
Abstract: Field observations have suggested for
quite some time that certain fish, turtles and whales have extremely
long maximum lifespan potential. Age validation techniques have
since confirmed these observations, but scientific analysis to
understand the genetic and biochemical basis of this longevity has
occurred only recently. On the Home page, the term 'negligible
senescence' is defined, background information about long-lived
animals is discussed, and age validation techniques are listed.
Subsequent website pages list the various projects to date,
including research results.
Introduction to Negligible
Senescence: Aging research has advanced
dramatically in the last several years, with many recent discoveries
about the biochemical and genetic components of aging. But
curiously, one potential area of study for aging research identified
over 70 years ago has not advanced until recently - the analysis of
long-lived animals. In the 1930's it was proposed that some fish do
not show signs of senescence (Bidder 1932). Even though biological
tools such as histology existed at that time, no known efforts were
made to examine these animals.
This new area of study in
biomedical gerontology has the potential to reveal the genetic and
biochemical processes that long-lived animals use to retard aging.
Although rockfish (genus Sebastes) have been the main focus, one of
our studies is on turtles, and whales are under consideration for
future studies. Leonard Hayflick, discoverer of the "Hayflick limit"
of cellular senescence and an advisor to this project, states that
"Guerin's project is not only unique, but probes an area of almost
total neglect in biogerontology, yet an area with more promise to
deliver valuable data than, perhaps, any
other".
Background on Negligible
Senescence: Caleb Finch at USC coined the term
"negligible senescence" to describe very slow or negligible aging
(Finch 1990). He listed several animals with this characteristic,
including rockfish, sturgeon, turtles, bivalves and possibly
lobsters. Later in a paper from the first Symposium on Organisms
with Slow Aging (which the Director of this project also spoke at),
Finch further described criteria to test the occurrence of
negligible aging. These include no observable age-related increase
in mortality rate or decrease in reproduction rate after maturity,
and no observable age-related decline in physiological capacity or
disease resistance (Finch and Austad 2001).
Accurate age
determination is important in studying long-lived animals. In
turtles, the determination of minimum age is relatively
straightforward, using tag and recapture methods. In many fish, the
most common technique is the analysis of annual growth rings in the
otolith, or ear bone (Bagenal 1974, McFarlane and Beamish 1995). Two
recent international symposia have focused entirely on the
importance of otolith measurement in fish life history studies
(Secor et al. 1995, Fossum et al. 2000). Another technique used by
fisheries management to provide an independent age estimate is the
radiometric approach, which utilizes a known radioactive decay
series in the core of bones (Bennett et al. 1982, Campana et al.
1990). Recent research that showed whales live over 200 years in
good health used aspartic acid racemization (George
1999).
Zoos have also compiled longevity information.
Alligators have been recorded up to eighty years of age, although it
is uncertain if death was due to senescence or environmental factors
(Snider, A.T., Bowler, J.K. Longevity of Reptiles and Amphibians in
North American Collections 1992, and also personal communication
with the Cincinnati Zoo 2001). Green sea turtles have been estimated
to take up to a maximum of 50 years to reach maturity in the wild,
due to their low protein diet (Bjorndal 1985). This is significant
because delayed reproduction is usually associated with a very slow
rate of aging. A 1994 issue of Gerontology was devoted to aging in
cold-blooded vertebrates; it compiled research showing that even
though some fish are long-lived, interestingly many are short-lived
and have senescence similar to that seen in mammals (Patnaik, B.K.
(Ed.), 1994).
Many of the above mentioned animals were
originally considered for the initial study of negligible
senescence. But in 1997 the project received data from the Alaska
Fish and Game on randomly sampled Yelloweye rockfish, commercially
caught off of Sitka, Alaska. The charts they provided
showed that 16% of the fish going to people's dinner tables were 50
years of age or older, with several over 100 years old! With the
knowledge that long-lived animals of this age were commercially
available, rockfish became the major research effort of the
AgelessAnimals project.
In a very intriguing analysis,
the project's Fish Ecologist, Gregor M. Cailliet, determined that
rockfish have both short-lived and long-lived members in the same
genus (Cailliet 2001). He found that maximum rockfish longevity
ranges in age from 12 years for the calico rockfish to 205 years for
the rougheye rockfish. Future studies on the project will compare
genetic and biochemical measurements between short-lived and
long-lived rockfish.
~~~~
|