Sperm head morphology is associated with sperm swimming speed: A comparative study of songbirds using electron microscopy
Evolution,
Journal Year:
2018,
Volume and Issue:
72(9), P. 1918 - 1932
Published: July 17, 2018
Sperm
exhibit
extraordinary
levels
of
morphological
diversification
across
the
animal
kingdom.
In
songbirds,
sperm
have
a
helically
shaped
head
incorporating
distinct
acrosomal
membrane
or
"helical
keel,"
form
and
extent
which
varies
species.
The
functional
significance
this
helical
shape,
however,
remains
unknown.
Using
scanning
electron
microscopy,
we
quantified
inter‐
intraspecific
variation
in
morphology
36
songbird
species
(Passeriformes:
Passerida).
phylogenetic
comparative
methods,
investigated
relationship
between
both
swimming
speed
frequency
extra‐pair
young
(EPY).
We
found
that
whose
had
relatively
more
pronounced
(i.e.,
long
acrosome,
short
nucleus,
wide
membrane,
waveform
along
"core")
faster‐swimming
sperm.
no
evidence
interspecific
EPY,
although
did
find
among‐
within‐male
traits
were
negatively
correlated
with
EPY.
Applying
principles
fluid
mechanics,
discuss
how
may
influence
speed,
suggest
further
studies
considering
aspects
beyond
length
are
needed
to
improve
our
understanding
structure‐function
relationships.
Language: Английский
Longer Sperm Swim More Slowly in the Canary Islands Chiffchaff
Cells,
Journal Year:
2021,
Volume and Issue:
10(6), P. 1358 - 1358
Published: May 31, 2021
Sperm
swimming
performance
affects
male
fertilization
success,
particularly
in
species
with
high
sperm
competition.
Understanding
how
morphology
impacts
is
therefore
important.
speed
hypothesized
to
increase
total
length,
relative
flagellum
length
(with
the
generating
forward
thrust),
and
midpiece
(as
contains
mitochondria).
We
tested
these
hypotheses
for
divergence
traits
five
island
populations
of
Canary
Islands
chiffchaff
(Phylloscopus
canariensis).
confirmed
incipient
mitochondrial
DNA
differentiation
between
Gran
Canaria
other
islands.
correlated
negatively
did
not
correlate
(for
only).
The
proportion
motile
cells
increased
on
only.
was
similar
across
thus
add
a
growing
number
studies
passerine
birds
that
do
support
morphology–swimming
hypotheses.
suggest
mechanics
are
sufficiently
different
from
mammalian
predictions
hydrodynamic
models
should
no
longer
be
applied
this
taxon.
While
both
likely
under
selection
passerines,
relationship
them
requires
further
elucidation.
Language: Английский
Positive correlations between pre‐ and post‐copulatory sexual traits in warblers
Journal of Avian Biology,
Journal Year:
2018,
Volume and Issue:
49(5)
Published: March 10, 2018
Theoretical
models
predict
that
investment
in
pre‐copulatory
and
post‐copulatory
sexually
selected
traits
should
trade‐off.
At
the
macroevolutionary
scale,
majority
of
studies
to
date
have
focused
on
male
weaponry
as
target
sexual
selection,
but
trade‐off
equally
apply
used
attract
females,
such
bird
song
plumage.
We
studied
Old
World
leaf
warblers
(Phylloscopidae),
a
group
socially
monogamous
songbirds
experience
relatively
high
levels
sperm
competition.
examined
relationships
between
duration
number
elements
with
length
across
21
species,
same
variables
combined
testes
mass
subset
these
species
(n
=
10).
Across
mass/sperm
were
generally
positively
correlated,
albeit
not
statistically
significantly
so
or
borderline
significance.
In
contrast
theory,
we
found
no
evidence
for
negative
associations
pre‐
traits.
argue
this
is
consequence
males
some
investing
more
into
overall
fertilization
success
(i.e.
sum
selection)
than
other
achieved
through
both
mate
attraction
Language: Английский
Weak geographical structure in sperm morphology across the range of two willow warbler Phylloscopus trochilus subspecies in Scandinavia
Journal of Avian Biology,
Journal Year:
2016,
Volume and Issue:
47(5), P. 731 - 741
Published: March 12, 2016
Sperm
morphology
is
highly
diversified
among
species
and
at
higher
taxonomic
levels.
In
birds,
there
also
increasing
evidence
of
geographical
differentiation
in
sperm
traits
within
species,
especially
those
with
strong
competition.
Geographical
divergences
might
imply
the
formation
a
reproductive
barrier
speciation
process.
Here
we
study
variation
willow
warblers
Phylloscopus
trochilus
context
Scandinavia,
across
range
two
subspecies
that
are
differentiated
certain
genetic
markers,
migratory
routes.
We
describe
patterns
genotypes
(two
previously
described
single‐nucleotide
polymorphism
(SNP)
markers
four
polymorphic
microsatellites);
wing
length,
tarsus
length
body
mass;
330
male
sampled
33
localities
Norway
(58°N–69°N).
Birds
were
on
average
larger
longer‐winged
north
(spp.
acredula
)
than
south
),
showed
sigmoid
change
SNP
allele
frequencies
around
65°N.
found
no
structuring
microsatellites.
There
was
Norway,
except
heads
longer
south.
head
associated
for
southern
alleles,
midpiece
weakly
one
markers.
Similar
among‐male
variances
total
sampling
sites
indicate
uniform
levels
competition
Norway.
conclude
remains
rather
undifferentiated
trait
between
warbler
which
consistent
pattern
shallow
divergence.
This
indicates
not
maintaining
narrow
hybrid
zone.
Language: Английский
Effects of fixatives and storage duration on avian sperm morphology
Journal of Ornithology,
Journal Year:
2022,
Volume and Issue:
164(1), P. 171 - 181
Published: Sept. 8, 2022
Abstract
Sperm
cells
are
variable
both
within
and
among
species.
To
be
able
to
accurately
measure
sperm
understand
their
function,
it
is
important
that
preserved
in
a
manner
maintains
structural
integrity.
Formalin
widely
used
fixative
storage
medium
for
cells,
but
few
studies
have
examined
the
effect
of
fixation
long-term
on
morphological
Ethanol
also
common
agent
tissue
samples,
here
we
examine
if
formalin
or
ethanol
alters
cell
size
We
found
no
significant
effects
process
fresh
fixed
ethanol.
Further,
there
were
consistent
length
changes
stored
over
period
227
days,
three
years.
A
comparison
across
13–14
years
time
showed
small
reduction
0.93%.
Furthermore,
initially
remained
quite
stable
dry
glass
slides
minimum
six
months
(we
mean
0.18%
after
6
months).
The
proportion
with
head
damage
was,
however,
much
higher
samples
than
those
formalin.
Overall,
70%
had
acrosome
versus
only
3%
Finding
intact
measuring
length,
therefore,
required
greater
effort
samples.
Our
findings
indicate
use
from
study
morphometrics
justified
either
fixative,
although
clearly
preserves
better.
Language: Английский