bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Feb. 22, 2023
Abstract
The
Hydra
nervous
system
is
the
paradigm
of
a
“simple
nerve
net”.
Nerve
cells
in
,
as
many
cnidarian
polyps,
are
organized
net
extending
throughout
body
column.
This
required
for
control
spontaneous
behavior:
elimination
leads
to
polyps
that
do
not
move
and
incapable
capturing
ingesting
prey
(Campbell,
1976).
We
have
re-examined
structure
by
immunostaining
fixed
with
novel
antibody
stains
all
.
Confocal
imaging
shows
there
two
distinct
nets,
one
ectoderm
endoderm,
unexpected
absence
endoderm
tentacles.
nets
contact
each
other.
High-resolution
TEM
serial
block
face
SEM
show
consist
bundles
parallel
overlapping
neurites.
Results
from
transgenic
lines
neurite
include
different
neural
circuits
hence
neurites
require
circuit-specific
recognition.
cell-specific
innexins
indicate
gap
junctions
can
provide
this
specificity.
occurrence
supports
model
continuous
growth
differentiation
lateral
addition
new
existing
net.
was
confirmed
tracking
newly
differentiated
cells.
Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: Dec. 13, 2023
Abstract
There
is
currently
little
information
about
the
evolution
of
gene
clusters,
genome
architectures
and
karyotypes
in
early
branching
animals.
Slowly
evolving
anthozoan
cnidarians
can
be
particularly
informative
these
features.
Here
we
report
chromosome-level
assemblies
two
related
anthozoans,
sea
anemones
Nematostella
vectensis
Scolanthus
callimorphus
.
We
find
a
robust
set
15
chromosomes
with
clear
one-to-one
correspondence
between
species.
Both
genomes
show
chromosomal
conservation,
allowing
us
to
reconstruct
ancestral
cnidarian
metazoan
blocks,
consisting
at
least
19
16
linkage
groups,
respectively.
that,
contrast
Bilateria,
Hox
NK
clusters
investigated
are
largely
disintegrated,
despite
presence
staggered
hox/gbx
expression
This
loss
microsynteny
conservation
may
facilitated
by
shorter
distances
cis-regulatory
sequences
their
cognate
transcriptional
start
sites.
no
evidence
for
topologically
associated
domains,
suggesting
fundamental
differences
long-range
regulation
compared
vertebrates.
These
data
suggest
that
large
sets
genes
have
been
retained
groups
some
extant
lineages;
yet,
higher
order
3D
architecture
evolved
only
after
cnidarian-bilaterian
split.
Philosophical Transactions of the Royal Society B Biological Sciences,
Journal Year:
2024,
Volume and Issue:
379(1901)
Published: March 18, 2024
The
freshwater
polyp
Hydra
uses
an
elaborate
innate
immune
machinery
to
maintain
its
specific
microbiome.
Major
components
of
this
toolkit
are
conserved
Toll-like
receptor
(TLR)-mediated
pathways
and
species-specific
antimicrobial
peptides
(AMPs).
Our
study
harnesses
advanced
technologies,
such
as
high-throughput
sequencing
machine
learning,
uncover
a
high
complexity
the
's
AMPs
repertoire.
Functional
analysis
reveals
that
these
against
diverse
members
microbiome
expressed
in
spatially
controlled
pattern.
Notably,
outer
epithelial
layer,
produced
mainly
neurons.
neuron-derived
secreted
directly
into
glycocalyx,
habitat
for
symbiotic
bacteria,
display
selectivity
spatial
restriction
expression.
In
endodermal
contrast,
cells
produce
abundance
different
including
arminin
hydramacin
families,
while
gland
secrete
kazal-type
protease
inhibitors.
Since
layer
lines
gastric
cavity
devoid
we
assume
endodermally
protect
from
intruding
pathogens.
conclusion,
employs
complex
set
distinct
tissue
layers
cell
types
combat
pathogens
stable
organized
This
article
is
part
theme
issue
‘Sculpting
microbiome:
how
host
factors
determine
respond
microbial
colonization’.
mBio,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 25, 2025
Eukaryotic
organisms
are
associated
with
complex
microbial
communities.
Changes
within
these
communities
have
been
implicated
in
disease
development.
Nonetheless,
it
remains
unclear
whether
changes
a
cause
or
consequence
of
disease.
Here,
we
report
causal
link
between
environment-induced
shifts
the
microbiota
and
Using
model
organism
Hydra,
observed
composition
when
transferring
laboratory-grown
Hydra
to
natural
lake
environments.
These
were
caused
not
only
by
new
colonizers,
through
process
community
coalescence
(merging
previously
separate
communities),
but
also
water
nutrients.
Moreover,
selective
manipulation
nutrient
environment
induced
compound-specific
followed
Finally,
L-arginine
supplementation
alone
transition
Pseudomonas
from
symbiotic
pathogenic,
leading
an
upregulation
immune
response
genes,
tissue
degradation,
host
death.
findings
challenge
notion
that
host-associated
is
exclusively
controlled
host,
highlighting
dynamic
interplay
epithelial
environment,
colonizer
pool,
conditions
surrounding
water.
Furthermore,
our
results
show
overfeeding
allows
for
uncontrolled
growth
versatile
interactions
host.
Environmental
may
thus
render
symbionts
potential
hazard
their
hosts,
blurring
divide
pathogenic
non-pathogenic
microbes.IMPORTANCEThis
study
highlights
critical
need
understand
environmental
factors
obtain
holistic
view
on
organismal
health.
Our
demonstrate
ecosystem-wide
trafficking
(community
coalescence)
reshape
profound
implications
By
exploring
nutrient-driven
composition,
research
finds
experimental
support
"overfeeding
hypothesis,"
which
states
alters
functionality
such
overabundance
nutrients
can
facilitate
development,
transforming
microbes
into
pathogens.
emphasize
role
metabolic
driving
pathogenicity.
provides
empirical
evidence
"pathogenic
potential"
concept,
challenging
traditional
distinctions
supporting
idea
any
microbe
become
under
certain
conditions.
Cells and Development,
Journal Year:
2023,
Volume and Issue:
174, P. 203846 - 203846
Published: April 28, 2023
Cnidarians
are
>600
million
years
old
and
considered
the
sister
group
of
Bilateria
based
on
numerous
molecular
phylogenetic
studies.
Apart
from
Hydra,
genomes
all
major
clades
Cnidaria
have
been
uncovered
(e.g.
Aurelia,
Clytia,
Nematostella
Acropora)
they
reveal
a
remarkable
completeness
metazoan
genomic
toolbox.
Of
particular
interest
is
model
system
aging
research,
regenerative
biology,
stem
cell
biology.
With
knowledge
gained
scRNA
it
now
possible
to
characterize
expression
profiles
types
with
great
precision.
In
functional
studies,
our
picture
Hydra
biology
has
changed,
we
in
process
obtaining
clear
homeostasis
properties
different
populations.
Even
though
often
compared
plant
systems,
new
data
germline
regeneration,
but
also
dynamics
plasticity
nervous
system,
show
that
its
simple
body
plan
represents
nutshell
prototype
an
animal
lineages,
whose
correspond
many
ways
Bilateria.
This
review
provides
overview
four
two
epithelial
lineages
constitute
ectoderm
endoderm,
as
well
multipotent
somatic
interstitial
lineage
(MPSC)
(GSC),
known
cells
Hydra.
The
Hydra
nervous
system
is
the
paradigm
of
a
‘simple
nerve
net’.
Nerve
cells
in
,
as
many
cnidarian
polyps,
are
organized
net
extending
throughout
body
column.
This
required
for
control
spontaneous
behavior:
elimination
leads
to
polyps
that
do
not
move
and
incapable
capturing
ingesting
prey
(Campbell,
1976).
We
have
re-examined
structure
by
immunostaining
fixed
with
novel
antibody
stains
all
.
Confocal
imaging
shows
there
two
distinct
nets,
one
ectoderm
endoderm,
unexpected
absence
endoderm
tentacles.
nets
contact
each
other.
High-resolution
TEM
(transmission
electron
microscopy)
serial
block
face
SEM
(scanning
show
consist
bundles
parallel
overlapping
neurites.
Results
from
transgenic
lines
neurite
include
different
neural
circuits
hence
neurites
require
circuit-specific
recognition.
cell-specific
innexins
indicate
gap
junctions
can
provide
this
specificity.
occurrence
supports
model
continuous
growth
differentiation
lateral
addition
new
existing
net.
was
confirmed
tracking
newly
differentiated
cells.
Cell Reports,
Journal Year:
2024,
Volume and Issue:
43(6), P. 114210 - 114210
Published: May 23, 2024
Hunger
and
satiety
can
have
an
influence
on
decision-making,
sensory
processing,
motor
behavior
by
altering
the
internal
state
of
brain.
This
process
necessitates
integration
peripheral
stimuli
into
central
nervous
system.
Here,
we
show
how
animals
without
a
system
such
as
cnidarian
Hydra
measure
integrate
neuronal
circuits
which
specific
populations
are
involved.
We
demonstrate
that
this
simple
system,
previously
referred
to
diffuse,
has
endodermal
subpopulation
(N4)
similar
enteric
(feeding-associated
behavior)
ectodermal
population
(N3)
performs
system-like
functions
(physiology/motor).
view
supposedly
could
open
important
window
origin
more
complex
systems.
Current Biology,
Journal Year:
2023,
Volume and Issue:
33(24), P. 5288 - 5303.e6
Published: Nov. 22, 2023
Although
recent
studies
indicate
the
impact
of
microbes
on
central
nervous
systems
and
behavior,
it
remains
unclear
how
relationship
between
functionality
system,
microbiota
evolved.
In
this
work,
we
analyzed
eating
behavior
Hydra,
a
host
that
has
simple
system
low-complexity
microbiota.
To
identify
neuronal
subpopulations
involved,
used
subpopulation-specific
cell
ablation
calcium
imaging.
The
role
was
uncovered
by
manipulating
diversity
natural
We
show
different
are
functioning
together
to
control
behavior.
Animals
with
drastically
reduced
microbiome
had
severe
difficulties
in
mouth
opening
due
significantly
increased
level
glutamate.
This
could
be
reversed
adding
full
complement
summary,
provide
mechanistic
explanation
Hydra's
controls
what
play
this.
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2024,
Volume and Issue:
unknown
Published: March 14, 2024
Many
animal
genomes
are
characterized
by
highly
conserved
chromosomal
homologies
that
pre-date
the
ancient
origin
of
this
clade.
Despite
such
conservation,
evolutionary
forces
behind
retention,
expansion,
and
contraction
elements,
resulting
macro-evolutionary
implications,
unknown.
Here
we
present
a
comprehensive
stem-cell
resolved
genomic
transcriptomic
study
fresh-water
cnidarian
Hydra,
an
its
high
regenerative
capacity,
ability
to
propagate
clonally,
apparent
lack
aging.
Using
single-haplotype
telomere-to-telomere
genome
assemblies
two
recently
diverged
hydra
strains,
show
how
history
elements
is
shaped
both
old
recent
transposable
element
(TE)
expansions.
Unique
features
biology
allowed
us
compare
individual
hydra's
three
stem
cell
lineages.
We
distinct
TE
families
active
at
transcriptional
levels
via
non-random
insertions
in
each
these
In
transcriptomes,
over
14,000
transcripts
were
composed
nearly
complete
sequences,
further
classification
into
families,
subfamilies,
loci
reveals
type-specific
expression.
The
TEs
include
differentially
contribute
changes
size
as
well
persistent
structural
variants
around
associated
with
proliferation.
Our
14
primarily
act
role
predominantly
DNA
elements.
Evolutionary
analysis
revealed
constitute
core
eukaryotic
metazoan
genomes.
results
suggest
for
self-renewing
components
persist
beyond
homologies.
Abstract
Hydractinia
symbiolongicarpus
is
a
pioneering
model
organism
for
stem
cell
biology,
being
one
of
only
few
animals
with
adult
pluripotent
cells
(known
as
i-cells).
However,
the
unavailability
chromosome-level
genome
assembly
has
hindered
comprehensive
understanding
global
gene
regulatory
mechanisms
underlying
function
and
evolution
i-cells.
Here,
we
report
first
H.
(HSymV2.0)
using
PacBio
HiFi
long-read
sequencing
Hi-C
scaffolding.
The
final
483
Mb
in
total
length
15
chromosomes
representing
99.8%
assembly.
Repetitive
sequences
were
found
to
account
296
(61%)
genome;
provide
evidence
at
least
two
periods
repeat
expansion
past.
A
25,825
protein-coding
genes
predicted
this
assembly,
which
include
93.1%
metazoan
Benchmarking
Universal
Single-Copy
Orthologs
(BUSCO)
set.
92.8%
(23,971
genes)
proteins
functionally
annotated.
showed
high
degree
macrosynteny
conservation
Hydra
vulgaris
genome.
This
will
be
an
invaluable
resource
research
community
that
enhances
broad
biological
studies
on
unique
organism.