Acoelomorph flatworm monophyly is a long-branch attraction artefact obscuring a clade of Acoela and Xenoturbellida
Proceedings of the Royal Society B Biological Sciences,
Journal Year:
2024,
Volume and Issue:
291(2031)
Published: Sept. 1, 2024
Acoelomorpha
is
a
broadly
accepted
clade
of
bilaterian
animals
made
up
the
fast-evolving,
morphologically
simple,
mainly
marine
flatworm
lineages
Acoela
and
Nemertodermatida.
Phylogenomic
studies
support
Acoelomorpha’s
close
relationship
with
slowly
evolving
similarly
simplistic
Xenoturbella
,
together
forming
phylum
Xenacoelomorpha.
The
phylogenetic
placement
Xenacoelomorpha
amongst
bilaterians
controversial,
some
supporting
as
sister
group
to
all
other
bilaterians,
implying
that
their
simplicity
may
be
representative
early
bilaterians.
Others
propose
this
an
error
resulting
from
fast-evolving
Acoelomorpha,
instead
suggest
they
are
degenerate
Ambulacraria.
Perhaps
result
debate,
internal
xenacoelomorph
relationships
have
been
somewhat
overlooked
at
phylogenomic
scale.
Here,
I
employ
highly
targeted
approach
detect
overcome
possible
in
between
acoelomorph
flatworms.
results
indicate
subphylum
long-branch
attraction
artefact
obscuring
previously
undiscovered
comprising
Acoela,
which
name
Xenacoela.
findings
also
not
This
study
provides
template
for
future
efforts
aimed
discovering
correcting
unrecognized
artefacts
throughout
tree
life.
Language: Английский
Genome assembly of the acoel flatworm Symsagittifera roscoffensis, a model for research on body plan evolution and photosymbiosis
G3 Genes Genomes Genetics,
Journal Year:
2022,
Volume and Issue:
13(2)
Published: Dec. 21, 2022
Symsagittifera
roscoffensis
is
a
well-known
member
of
the
order
Acoela
that
lives
in
symbiosis
with
algae
Tetraselmis
convolutae
during
its
adult
stage.
Its
natural
habitat
eastern
coast
Atlantic,
where
at
specific
locations
thousands
individuals
can
be
found,
mostly,
lying
large
pools
on
surface
sand
low
tide.
As
it
has
been
thought
as
proxy
for
ancestral
bilaterian
animals;
however,
phylogenetic
position
remains
still
debated.
In
to
understand
basic
structural
characteristics
acoel
genome,
we
sequenced
and
assembled
genome
aposymbiotic
species
S.
roscoffensis.
The
size
this
was
measured
range
910-940
Mb.
Sequencing
performed
using
PacBio
Hi-Fi
technology.
Hi-C
RNA-seq
data
were
also
generated
scaffold
annotate
it.
resulting
assembly
1.1
Gb
(covering
118%
estimated
size)
highly
continuous,
N50
1.04
repetitive
fraction
61%,
which
85%
(half
genome)
are
LTR
retrotransposons.
Genome-guided
transcriptome
identified
34,493
genes,
29,351
protein
coding
(BUSCO
score
97.6%),
30.2%
genes
spliced
leader
trans-spliced.
completeness
suggests
used
extensively
characterize
gene
families
conduct
accurate
phylogenomic
reconstructions.
Language: Английский
The draft genome of the microscopic Nemertoderma westbladi sheds light on the evolution of Acoelomorpha genomes
Frontiers in Genetics,
Journal Year:
2023,
Volume and Issue:
14
Published: Sept. 26, 2023
Xenacoelomorpha
is
a
marine
clade
of
microscopic
worms
that
an
important
model
system
for
understanding
the
evolution
key
bilaterian
novelties,
such
as
excretory
system.
Nevertheless,
genomics
has
been
restricted
to
few
species
either
can
be
cultured
in
lab
or
are
centimetres
long.
Thus
far,
no
genomes
available
Nemertodermatida,
one
group's
main
clades
and
whose
origin
dated
more
than
400
million
years
ago.
Language: Английский