Abstract
Telomeres
are
short
repetitive
DNA
sequences
capping
the
ends
of
chromosomes.
Telomere
shortening
occurs
during
cell
division
and
may
be
accelerated
by
oxidative
damage
or
ameliorated
telomere
maintenance
mechanisms.
Consequently,
length
changes
with
age,
which
was
recently
confirmed
in
a
large
meta‐analysis
across
vertebrates.
However,
based
on
correlation
between
it
concluded
that
can
used
as
tool
for
chronological
age
estimation
animals.
Correlation
should
not
confused
predictability,
current
data
studies
suggest
telomeres
cannot
to
reliably
predict
individual
age.
There
biological
reasons
why
there
is
variation
dynamics,
mainly
due
high
susceptibility
wide
range
environmental,
but
also
genetic
factors,
rendering
unfeasible
estimation.
The
use
largely
misguided
effort,
its
occasional
reappearance
literature
raises
concerns
will
mislead
resources
wildlife
conservation.
Frontiers in Physiology,
Год журнала:
2023,
Номер
14
Опубликована: Ноя. 22, 2023
Telomere
dynamics
in
hibernating
species
are
known
to
reflect
seasonal
changes
somatic
maintenance.
Throughout
hibernation,
the
periodic
states
of
rewarming,
as
inter-bout
euthermia
or
arousals,
associated
with
high
metabolic
costs
including
shortening
telomeres.
In
active
season,
if
energetic
resources
available,
telomere
length
can
be
restored
preparation
for
upcoming
winter.
The
mechanism
elongation
has
not
been
clearly
demonstrated,
although
action
ribonucleoprotein
complex,
telomerase,
implicated
many
species.
Here
we
tested
levels
telomerase
activity
garden
dormouse
(
Eliomys
quercinus
)
at
different
time
points
throughout
year
and
across
ages
from
liver
tissues
male
juveniles
adults.
We
found
that
is
seasons
(during
torpor
euthermia,
plus
season)
but
there
was
a
substantial
decrease
month
prior
hibernation.
Telomerase
were
consistent
age
groups
independent
feeding
regime
birth
(early
late
born).
detected
broadly
lengths
measured
same
tissues.
hypothesise
i)
used
by
dormice
maintenance
telomeres
ii)
kept
until
pre-hibernation
when
diverted
increasing
fat
reserves
overwintering.
no
evidence
final
increase
which
other
rodents.
Journal of Experimental Zoology Part A Ecological and Integrative Physiology,
Год журнала:
2024,
Номер
341(4), С. 338 - 344
Опубликована: Янв. 22, 2024
Abstract
Telomere
length
and
dynamics
are
commonly
used
biomarkers
of
somatic
state,
yet
the
role
telomeres
underlying
aging
process
is
still
debated.
Indeed,
to
date,
empirical
evidence
for
an
association
between
age
telomere
mixed.
Here,
we
test
if
age‐dependency
can
provide
a
potential
explanation
reported
inconsistencies
across
studies.
To
this
end,
quantified
by
restriction
fragment
analysis
in
two
groups
Japanese
quail
(
Coturnix
japonica
)
that
differed
their
distribution.
One
group
consisted
young
adults
only,
whereas
second
wide
range
ages.
In
group,
there
was
highly
significant
negative
age,
no
found
all‐ages
group.
This
difference
not
due
length‐dependent
selective
disappearance.
Our
results
shows
age‐dependent
suggest
costs
benefits
associated
with
maintenance
dynamic
individual's
life
course.
Abstract
In
evolutionary
ecology,
two
classes
of
explanations
are
frequently
invoked
to
explain
“early
life
effects”
on
adult
outcomes.
Developmental
constraints
(DC)
contend
that
costs
early
adversity
arise
from
limitations
places
optimal
development.
Adaptive
response
(AR)
hypotheses
propose
later
outcomes
will
be
worse
when
and
environments
poorly
“matched.”
Here,
we
use
recently
proposed
mathematical
definitions
for
these
a
quadratic-regression
based
approach
test
the
long-term
consequences
variation
in
developmental
fertility
wild
baboons.
We
evaluate
whether
low
rainfall
and/or
dominance
rank
during
development
predict
three
female
measures
adulthood,
any
observed
relationships
consistent
with
DC
AR.
Neither
nor
difference
between
adulthood
predicted
measures.
Females
who
were
low-ranking
had
an
elevated
risk
losing
infants
life,
greater
change
infant
loss.
However,
both
effects
statistically
marginal
alternative
explanations,
including
environmental
quality
effects.
Consequently,
our
data
do
not
provide
compelling
support
either
common
evolution
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2022,
Номер
unknown
Опубликована: Фев. 11, 2022
Abstract
In
many
species,
individuals
who
experience
harsh
conditions
during
development
often
have
poor
health
and
fitness
outcomes
in
adulthood
relative
to
peers
do
not.
There
are
two
classes
of
evolutionary
hypotheses
for
the
origins
these
early
life
contributors
inequality
adulthood:
developmental
constraints
(DC)
models,
which
focus
on
deleterious
effects
low-quality
early-life
environments,
predictive
adaptive
response
(PAR)
hypotheses,
emphasize
cost
mismatches
between
adult
environments.
Distinguishing
DC
PAR
models
empirically
is
difficult
both
conceptual
analytical
reasons.
Here,
we
resolve
this
difficulty
by
providing
explicit
mathematical
definitions
DC,
PARs,
related
concepts,
propose
a
novel,
quadratic
regression-based
statistical
test
derived
from
definitions.
Simulations
show
that
approach
improves
ability
discriminate
common
alternative
based
testing
interaction
Simulated
data
indicate
conflates
PARs
with
while
regression
yields
high
sensitivity
specificity
detecting
PARs.
Our
results
highlight
value
linking
verbal
visual
formal
treatment
understanding
inequitable
outcomes.
Research Square (Research Square),
Год журнала:
2022,
Номер
unknown
Опубликована: Ноя. 14, 2022
Abstract
Telomeres,
the
nucleotide
sequences
that
protect
ends
of
eukaryotic
chromosomes,
shorten
with
each
cell
division
and
telomere
loss
may
be
increased
by
factors
such
as
oxidative
stress.
Telomere
length
(TL)
decreases
age
in
several
species,
TL
or
change
(∆TL)
have
emerged
biomarkers
reflecting
experienced
In
this
study,
we
tracked
changes
throughout
natural
lifespan
(from
a
few
months
to
almost
9
years)
free-living
house
sparrows
(
Passer
domesticus
)
two
different
island
populations.
was
measured
nestlings
subsequently
up
4
times
during
their
lifetime.
generally
decreased
(senescence),
but
also
observed
instances
lengthening
within
individuals.
We
found
some
evidence
for
selective
disappearance
individuals
shorter
telomeres
through
life.
Early-life
positively
predicted
later-life
TL,
within-individual
repeatability
low
(9.2%).
Using
genetic
pedigrees,
moderate
heritability
∆TL
h
2
=
0.21),
which
higher
than
heritabilities
early-life
0.14)
measurements
0.15).
Cohort
effects
explained
considerable
proportions
variation
(60%),
(53%),
(37%),
suggests
persistent
impacts
environment
on
lifelong
dynamics.
Individual
were
independent
TL.
Finally,
there
weak
population
differences
linked
ecological
habitat
types.
Combined,
our
results
show
individual
biology
is
highly
dynamic
influenced
both
environmental
conditions.
Authorea (Authorea),
Год журнала:
2023,
Номер
unknown
Опубликована: Май 12, 2023
Telomeres
are
chromosome
protectors
that
shorten
during
cell
replication
and
in
stressful
conditions.
Developing
individuals
susceptible
to
telomere
erosion
when
their
growth
is
fast
resources
limited.
This
critical
because
the
rate
of
attrition
early
life
linked
health
span
adults.
The
metabolic
hypothesis
(MeTA)
suggests
dynamics
can
respond
biochemical
signals
conveying
information
about
organism’s
energetic
state.
Among
these
glucocorticoids
(hormones
promote
catabolic
processes,
potentially
impairing
costly
maintenance)
nucleotides,
which
activate
anabolic
pathways
though
cellular
enzyme
target
rapamycin
(TOR)
preventing
attrition.
During
energetically
demanding
phase,
regulation
telomeres
response
two
contrasting
signals—one
promoting
maintenance
other
inducing
attrition—provides
an
ideal
experimental
setting
test
MeTa.
We
studied
nestlings
a
rapidly
developing
free-living
passerine,
great
tit
(Parus
major),
either
received
(Cort-chicks),
nucleotides
(Nuc-chicks),
or
combination
both
(NucCort-chicks)
all
compared
with
controls
(Cnt-chicks).
Contrary
Cort-chicks,
showed
attrition,
NucCort-chicks,
did
not.
NucCort-chicks
was
only
group
showing
increased
gene
expression
telo2
(proxy
for
TOR
activation),
mitochondrial
enzymes
ATP
production
(atp5f1a-atp5f1b-cox6a1-cox4)
higher
efficiency
aerobically
producing
ATP.
had
also
genes
(trf2)
enzymatic
antioxidant
(gpx4-sod1).
findings
show
availability
crucial
environments.
American Journal of Human Biology,
Год журнала:
2023,
Номер
35(10)
Опубликована: Июль 19, 2023
Telomere
length
(TL)
attrition
is
related
to
chronic
disease
risk.
However,
less
known
on
whether
TL
predicts
infectious
outcomes,
especially
in
childhood.
We
examined
leukocyte
(LTL)
was
associated
with
subsequent
morbidity
schoolchildren.We
assessed
LTL
717
Colombian
children
5-12
years-old
at
the
beginning
of
a
school
year
and
followed
them
through
for
daily
occurrence
common
infection
symptoms
doctor
visits.
estimated
adjusted
incidence
rate
ratios
(IRR)
95%
confidence
intervals
(CI)
gastrointestinal
respiratory
syndromes
quartiles
standardized
Z
score
per
unit
score.A
longer
increased
all
considered.
Adjusted
IRR
(95%
CI)
were
1.55
(1.20,
2.00)
diarrhea
vomiting,
1.34
(1.13,
1.60)
cough
fever,
1.70
(1.28,
2.28)
ear
infection,
1.66
(1.36,
2.02)
visits
symptoms.Longer
morbidities
middle
