Uncovering the Genetic Basis of Heterodichogamy inPterocaryaandCyclocaryaUsing a Low-Input Pan-Genomic Approach
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 11, 2025
Abstract
The
heterodichogamous
mating
system,
characterized
by
two
distinct
types
(protogyny
and
protandry),
is
rare
among
flowering
plants,
but
it
present
in
nearly
all
species
Juglandaceae
(the
walnut
family).
Recent
studies
have
identified
structural
variations
underlying
heterodichogamy
Juglans
Carya
.
To
verify
the
independent
origins
of
this
trait
investigate
whether
also
drive
closely
related
genera,
we
explored
its
genetic
basis
Pterocarya
Cyclocarya
Using
a
pan-genome
graph
approach,
variation
region
associated
with
across
genus.
This
includes
30
kb
tandem
repeats
dominant
allele
an
insertion
recessive
allele,
shared
polymorphisms
spanning
78
from
3′UTR
S12e
,
covering
FAF-like
gene,
to
Gypsy
transposable
element.
Downstream
analyses
suggest
that
specific
expression
gene
small
RNAs
uniquely
expressed
regulate
heterodichogamy.
Further
investigation
nine
candidate
loci
heterodichogamy,
which
are
non-homologous
regions
those
found
These
findings
provide
novel
evidence
for
multiple
originations
convergent
regulating
highlight
utility
approaches
deciphering
variation-associated
traits.
Language: Английский
Does chromoanagenesis play a role in the origin of B chromosomes?
Heredity,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 19, 2025
Abstract
B
chromosomes
(Bs)
exist
in
addition
to
the
standard
(A)
a
wide
range
of
species.
The
process
underlying
their
origin
is
still
unclear.
We
propose
pathways
intra-
and
interspecific
based
on
known
mechanisms
chromosome
evolution
available
knowledge
sequence
composition
different
speculate
that
mitotic
or
meiotic
segregation
error
one
more
A
initiates,
via
chromoanagenesis,
formation
proto-B
chromosome.
In
second
step,
accumulate
chromosome-
organelle-derived
sequences
over
time,
most
likely
DNA
double-strand
break
(DSB)
mis-repair.
Consequently,
original
structure
early
stage
becomes
masked
by
continuous
incorporation.
similarity
between
integrated
into
donor
decreases
time
if
there
no
selection
pressure
these
chromosomes.
However,
besides
also
other
leading
might
exist.
Language: Английский
Genome sequence of the wild species, Spinacia tetrandra, including a phased sequence of the extensive sex‐linked region, revealing partial degeneration in evolutionary strata with unusual properties
New Phytologist,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 25, 2025
Summary
Genetic
degeneration
is
a
striking
feature
of
Y
chromosomes,
often
involving
losses
many
genes
carried
on
the
X
chromosome.
However,
time
course
gene
remains
unclear.
Sex
chromosomes
plants
evolved
more
recently
than
animals'
highly
degenerated
ones,
making
them
ideal
for
studying
timing.
To
investigate
Spinacia
sex
chromosome
evolution
and
degeneration,
we
compared
genome
sequences
cultivated
oleracea
,
with
small
Y‐linked
region
Chr4,
its
two
wild
relatives.
In
spinach
closest
relative
turkestanica
duplication
(YDR)
introduced
male‐determining
factor
into
Chr4's
low‐recombining
pericentromeric
region.
other
words,
turnover
event
occurred
in
these
species'
recent
common
ancestor.
The
homologous
Chr4
distantly
related
S.
tetrandra
has
c
.
133
Mb
completely
sex‐linked
partially
region,
possibly
reflecting
ancestral
state.
Sequence
divergence
analysis
suggests
that
‘evolutionary
strata’
shortly
before
lineages
split.
Consistent
hypothesis,
YDR
species
not
within
older
stratum.
We
discuss
unexpected
findings
genetic
genomic
rearrangements,
repetitive
sequence
density
are
all
greatest
younger
Language: Английский