Why do sex chromosomes progressively lose recombination?
Trends in Genetics,
Год журнала:
2024,
Номер
40(7), С. 564 - 579
Опубликована: Апрель 27, 2024
Язык: Английский
Genome biology and evolution of mating-type loci in four cereal rust fungi
PLoS Genetics,
Год журнала:
2024,
Номер
20(3), С. e1011207 - e1011207
Опубликована: Март 18, 2024
Permanent
heterozygous
loci,
such
as
sex-
or
mating-compatibility
regions,
often
display
suppression
of
recombination
and
signals
genomic
degeneration.
In
Basidiomycota,
two
distinct
loci
confer
mating
compatibility.
These
encode
homeodomain
(
HD
)
transcription
factors
pheromone
receptor
Pra
)-ligand
allele
pairs.
To
date,
an
analysis
genome
level
mating-type
(MAT)
is
lacking
for
obligate
biotrophic
basidiomycetes
in
the
Pucciniales
,
order
containing
serious
agricultural
plant
pathogens.
Here,
we
focus
on
four
species
Puccinia
that
infect
oat
wheat,
including
P
.
coronata
f.
sp.
avenae
graminis
tritici
triticina
striiformis
MAT
are
located
separate
chromosomes
supporting
previous
hypotheses
a
tetrapolar
compatibility
system
The
genes
multiallelic
all
while
PR
locus
appears
biallelic,
except
which
potentially
has
multiple
alleles.
largely
conserved
their
macrosynteny,
both
within
between
species,
without
strong
suppression.
Regions
proximal
to
locus,
however,
displayed
signs
degeneration
three
with
biallelic
locus.
Our
observations
support
link
suppression,
degeneration,
diversity
consistent
recent
mathematical
modelling
simulations.
Finally,
confirm
expressed
during
asexual
infection
cycle,
propose
this
may
regulating
nuclear
maintenance
pairing
spore
formation.
study
provides
insights
into
evolution
key
pathogenic
species.
Understanding
can
help
predict
possible
combinations
pairs,
generated
by
sexual
reproduction
somatic
recombination,
potential
new
virulent
isolates
these
important
Язык: Английский
Repeated loss of function at HD mating-type genes and of recombination in anther-smut fungi
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Май 28, 2025
Basidiomycete
fungi
typically
have
two
mating-type
loci
controlling
mating
compatibility,
HD
and
PR,
residing
on
different
chromosomes.
Loss-of-function
in
compatibility
has
been
reported
at
the
PR
genes
a
few
heterothallic
basidiomycetes,
but
not
for
genes.
In
Microbotryum
anther-smut
fungi,
there
repeated
linkage
events
between
through
chromosome
fusions,
leading
to
non-recombining
regions.
Here,
we
found
that
sister
species
parasitizing
Dianthus
plants,
M.
superbum
shykoffianum,
as
well
distantly
related
scorzonerae,
their
chromosomes,
with
fused
part
of
ancestral
chromosome.
addition,
recombination
suppression
extended
stepwise,
generating
evolutionary
strata.
all
three
species,
lost
function
natural
diploid
strains
being
often
homozygous
locus.
Strains
could
be
disrupted
HD2
gene,
was
hardly
expressed
during
mating.
Mating
tests
confirmed
single
genetic
factor
controlled
haploid
identical
alleles
mate
produce
hyphae.
This
study
shows
unifactorial
determinism
can
evolve,
repeatedly,
from
bifactorial
system,
by
mechanisms.
Язык: Английский
The Sordariomycetes: an expanding resource with Big Data for mining in evolutionary genomics and transcriptomics
Frontiers in Fungal Biology,
Год журнала:
2023,
Номер
4
Опубликована: Июнь 30, 2023
Advances
in
genomics
and
transcriptomics
accompanying
the
rapid
accumulation
of
omics
data
have
provided
new
tools
that
transformed
expanded
traditional
concepts
model
fungi.
Evolutionary
flourished
with
use
classical
newer
fungal
models
facilitate
study
diverse
topics
encompassing
biology
development.
Technological
advances
also
created
opportunity
to
obtain
mine
large
datasets.
One
such
continuously
growing
dataset
is
Sordariomycetes,
which
exhibit
a
richness
species,
ecological
diversity,
economic
importance,
profound
research
history
on
amenable
models.
Currently,
3,574
species
this
class
been
sequenced,
comprising
nearly
one-third
available
ascomycete
genomes.
Among
these
genomes,
multiple
representatives
genera
Язык: Английский
Genetic differentiation in the MAT-proximal region is not sufficient for suppressing recombination in Podospora anserina
G3 Genes Genomes Genetics,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 24, 2025
Recombination
is
advantageous
over
the
long-term,
as
it
allows
efficient
selection
and
purging
deleterious
mutations.
Nevertheless,
recombination
suppression
has
repeatedly
evolved
in
sex
mating-type
chromosomes.
The
evolutionary
causes
for
proximal
mechanisms
preventing
crossing
overs
are
poorly
understood.
Several
hypotheses
have
recently
been
suggested
based
on
theoretical
models,
particular
that
divergence
could
accumulate
neutrally
around
a
sex-determining
region
reduce
rates,
self-reinforcing
process
foster
progressive
extension
of
suppression.
We
used
ascomycete
fungus
Podospora
anserina
investigating
these
questions:
0.8
Mbp
its
locus
non-recombining,
despite
being
collinear
between
two
mating
types.
This
mostly
selfing,
resulting
highly
homozygous
individuals,
except
non-recombining
displays
differentiation
Here,
we
test
hypothesis
sequence
alone
responsible
cessation.
replaced
mat-
idiomorph
by
mat+
idiomorph,
to
obtain
strain
sexually
compatible
with
reference
isogenic
this
MAT-proximal
region.
Crosses
showed
was
still
suppressed
mutant
strains,
indicating
other
than
inversions
or
mere
fungus.
finding
suggests
selective
likely
acted
suppressing
recombination,
spread
epigenetic
marks,
neutral
model
nucleotide
does
not
seem
hold
P.
anserina.
Язык: Английский
Huge genetic diversity ofSchizothecium tetrasporum(Wint.). N. Lundq.: delimitation of 18 species distributed into three complexes through genome sequencing
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2025,
Номер
unknown
Опубликована: Март 27, 2025
Abstract
Analyses
of
the
genetic
diversity
well-studied
fungi
Sordariales
order,
such
as
Neurospora
spp.
and
Podospora
anserina
(syn.
Triangularia
),
have
shown
that
species
classically
defined
by
morphology
are
often
complexes
cryptic
species.
Here,
we
report
on
delimitation
among
76
strains
producing
mycelium
sexual
reproductive
structures
identical
to
those
pseudo-homothallic
Schizothecium
tetrasporum
Neoschizothecium
).
Their
whole
genomes
were
sequenced
well
six
closely
related
but
eight-spored
asci
instead
four-spored
ones.
The
clustering
based
Average
Nucleotide
Identity
(ANI)
between
identified
eighteen
grouped
into
three
clades,
which
further
supported
a
phylogenetic
tree
constructed
with
genome
Single
Polymorphisms
(SNPs).
Based
their
contrasting
breeding
systems
large
evolutionary
distances,
considered
clades
distinct
complexes.
Indeed,
two
them,
pseudotetrasporum
complexes,
contains
asci,
while
third
one,
named
octosporum
,
heterothallic
asci.
Surprisingly
it
was
nestled
Our
data
reveals
thus
huge
morpho-species
convergent
evolution
pseudo-homothallism
or
reversion
heterothallism
within
An
epitype
for
sensus
stricto
is
seventeen
new
formally
described.
Язык: Английский
Dynamics of transposable element accumulation in the non-recombining regions of mating-type chromosomes in anther-smut fungi
Nature Communications,
Год журнала:
2023,
Номер
14(1)
Опубликована: Сен. 14, 2023
In
the
absence
of
recombination,
number
transposable
elements
(TEs)
increases
due
to
less
efficient
selection,
but
dynamics
such
TE
accumulations
are
not
well
characterized.
Leveraging
a
dataset
21
independent
events
recombination
cessation
different
ages
in
mating-type
chromosomes
Microbotryum
fungi,
we
show
that
TEs
rapidly
accumulated
regions
lacking
content
reached
plateau
at
ca.
50%
occupied
base
pairs
by
1.5
million
years
following
suppression.
The
same
superfamilies
have
expanded
independently
evolved
non-recombining
regions,
particular
rolling-circle
replication
(Helitrons).
Long-terminal
repeat
(LTR)
retrotransposons
Copia
and
Ty3
also
expanded,
through
transposition
bursts
(distinguished
from
gene
conversion
based
on
LTR
divergence),
with
both
autosomes
affected,
suggesting
constitute
reservoirs.
This
study
improves
our
knowledge
genome
evolution
showing
can
accumulate
bursts,
non-linear
decelerating
dynamics.
Язык: Английский
Genome biology and evolution of mating type loci in four cereal rust fungi
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Март 2, 2023
Abstract
Obligate
heterozygous
loci
such
as
sex-
or
mating-compatibility
regions
often
display
suppression
of
recombination
and
signals
genomic
degeneration.
In
Basidiomycota,
two
distinct
gene
confer
mating
compatibility.
These
encode
for
homeodomain
(
HD
)
transcription
factors
pheromone
receptor
Pra
)-ligand
pairs.
To
date
genome
level
type
MAT
analysis
is
lacking
obligate
biotrophic
basidiomycetes
in
the
order
Pucciniales
,
which
contains
many
economically
important
plant
pathogens.
Here,
we
focus
on
four
Puccinia
cereal
rust
species,
including
P.
coronata
f.
sp.
avenae
graminis
tritici
triticina
striiformis
infect
oat
wheat.
are
located
separate
chromosomes
supporting
previous
hypotheses
tetrapolar
types
.
The
locus
multiallelic
all
species
while
PR
appears
to
be
biallelic
except
displays
genetic
features
more
than
alleles.
were
largely
conserved
their
macrosynteny
within
between
without
strong
suppression.
proximate
regions,
however,
displayed
extensive
signs
degeneration
three
with
a
clear
locus.
observations
suggest
correlation
suppression,
allele
status
consistent
recent
mathematical
modelling
simulations.
Finally,
confirm
evolutionary
conservation
expression
during
asexual
infection
cycle
host
propose
related
correct
nuclear
pairing
spore
formation.
Together,
our
study
provides
insights
into
evolution
key
pathogenic
species.
This
detailed
understanding
predict
possible
combinations
pairs
that
can
arise
via
sexual
reproduction
somatic
enable
newly
virulent
isolates
these
Author
summary
Sex
animals
some
plants
determined
by
sex
chromosomes.
fungi,
mate
compatibility
loci,
share
around
loci.
fungal
pathogens
from
cause
diseases
wheat
oat.
We
show
one
multiallelic,
other
biallelic.
shows
deterioration
an
increase
transposable
elements
deserts
surrounding
Our
findings
biology
will
lead
better
prediction
novel
large
scale
pandemics
agriculture.
Язык: Английский
Sheltered load in fungal mating-type chromosomes revealed by fitness experiments
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 11, 2024
Abstract
Sex
chromosomes
and
mating-type
can
carry
large
regions
with
suppressed
recombination.
In
these
non-recombining
regions,
recessive
deleterious
mutations
are
expected
to
occur,
as
i)
they
predicted
accumulate
a
result
of
lower
efficacy
selection,
ii)
may
even
pre-exist
drive
the
evolution
recombination
suppression.
Multiple
genomic
analyses
have
indirectly
inferred
presence
in
sex
chromosomes,
but
direct
experimental
evidence
remains
scarce.
Here,
we
performed
fitness
assays
fungi
megabase-large
young
around
locus,
using
Schizothecium
tetrasporum
Podospora
anserina
species
complexes,
test
whether
heterokaryons
(diploid-like,
heterozygous
at
locus)
exhibited
advantage
over
homokaryons
(haploid-like,
single
allele),
terms
spore
germination
dynamics
or
mycelium
growth
speed,
under
different
conditions
light
temperature.
We
found
faster
compared
one
for
P.
18°C,
S.
tritetrasporum
22°C
light,
also
dark
.
These
findings
suggest
sheltered
load,
i.e.
state
near
highly
homozygous
otherwise.
Leveraging
on
assets
fungi,
allowing
cultivating
separately
haploid-like
diploid-like
life
stages,
our
experiments
provided
rare
load
mating-compatibility
loci,
which
is
crucial
understanding
sex-related
chromosome
evolution.
Язык: Английский
Genetic differentiation in the MAT-proximal region is not sufficient for suppressing recombination in Podospora anserina
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 7, 2024
ABSTRACT
Recombination
is
advantageous
over
the
long-term,
as
it
allows
efficient
selection
and
purging
deleterious
mutations.
Nevertheless,
recombination
suppression
has
repeatedly
evolved
in
sex
chromosomes
mating-type
chromosomes.
The
evolutionary
causes
for
proximal
mechanisms
preventing
crossing
overs
are
still
poorly
understood.
Several
hypotheses
have
recently
been
suggested
based
on
theoretical
models,
particular,
that
divergence
could
accumulate
neutrally
around
a
sex-determining
region
reduce
rates,
self-reinforcing
process
foster
progressive
extension
of
suppression.
ascomycete
fungus
Podospora
anserina
an
excellent
model
investigating
these
questions.
A
0.8
Mb
locus
non-recombining,
despite
being
collinear
between
two
mating
types.
This
mostly
selfing,
so
strains
highly
homozygous,
except
non-recombining
displays
differentiation
Here,
we
generated
mutant
to
test
hypothesis
sequence
alone
responsible
cessation.
We
replaced
mat-
idiomorph
by
mat+
idiomorph,
obtain
strain
sexually
compatible
with
reference
isogenic
this
MAT
-proximal
region.
Crosses
showed
was
suppressed
strains,
indicating
other
than
inversions
or
mere
fungus.
finding
suggests
selective
likely
acted
suppressing
recombination,
neutral
does
not
seem
hold,
at
least
ARTICLE
SUMMARY
In
many
organisms,
observed
locus.
,
within
800kb
natural
genome
mating-types,
displaying
heterozygosity.
To
determine
if
heterozygosity
can
be
lack
were
engineered
isogenic,
including
inhibition
persisted,
cause
Our
study
provides
interesting
insight
molecular
inhibition.
Язык: Английский