Spontaneous Bending of Hydra Tissue Fragments Driven by Supracellular Actomyosin Bundles Jian Su1 2Haiqin Wang1 2Zhongyu Yan1and Xinpeng Xu1 2

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Spontaneous Bending of Hydra Tissue Fragments Driven by Supracellular Actomyosin
Bundles
Jian Su,1, 2 Haiqin Wang,1, 2 Zhongyu Yan,1and Xinpeng Xu1, 2,
1Guangdong Technion - Israel Institute of Technology,
241 Daxue Road, Shantou, Guangdong, China, 515063
2Technion – Israel Institute of Technology, Haifa, Israel, 3200003
(Dated: November 22, 2022)
Hydra tissue fragments excised freshly from Hydra body bend spontaneously to some quasi-stable
shape in several minutes. We propose that the spontaneous bending is driven mechanically by
supracellular actomyosin bundles inherited from parent Hydra. An active-laminated-plate model is
constructed, from which we predict that the fragment shape characterized by spontaneous curvature
is determined by its anisotropy in contractility and elasticity. The inward bending to endoderm side
is ensured by the presence of a soft intermediate matrix (mesoglea) layer. The bending process
starts diffusively from the edges and relaxes exponentially to the final quasi-stable shape. Two
characteristic time scales are identified from the dissipation due to viscous drag and interlayer
frictional sliding, respectively. The former is about 0.01 seconds, but the latter is much larger,
about several minutes, consistent with experiments.
Hydra is a multicellular fresh-water polyp, which ex-
hibits remarkable regeneration capabilities, making it an
excellent model system for studying tissue morphogen-
esis [13]. The Hydra body consists of a single-axis
hollow-cylindrical tube (about 510 mm long) [1], which
has a triple-layer structure composed of two epithelial
cell layers (endoderm and ectoderm) that are adhered
together by an intermediate soft layer of extracellular
matrix (called mesoglea) as shown in Fig. 1(b). Hydra
body shape is maintained by a contractile actomyosin
cytoskeleton [4], which shows a highly-aligned orienta-
tion over supracellular scales (see Fig. 1(b)): the ac-
tomyosin bundles are longitudinally oriented (along the
tube axis) in the ectoderm and circularly oriented in the
endoderm. Regenerating Hydras use their cytoskeleton
to regulate their cells and to guide the regeneration pro-
cess [4]. When fragments are excised from the adult Hy-
dra body, the supracellular pattern of cytoskeletal bun-
dles are inherited, survive, and finally become a part of
the new daughter Hydra. These supracellular cytoskele-
tal bundles provide structural “memory” of the align-
ment along the body axis [4]. They generate mechanical
forces and direct the alignment of cytoskeleton in regions
where the supracellular order is lacked in the early stage
of regeneration.
At the initial stage of the regeneration of Hydra tis-
sue fragments that are excised freshly from adult Hydra
body [4,5], the fragments bend spontaneously to some
quasi-stable (or mechanical-equilibrium) shape in several
minutes (see Fig. 1(a)). Subsequently, the cytoskeleton
of the fragment remodels to find a balance between main-
taining its pre-existing organization and adapting to the
new curved conditions. After about one hour of the
bending-remodeling loop, the excised fragments fold into
small hollow spheroids [4,5].
In this Letter we focus on the initial spontaneous bend-
ing of Hydra fragments. Since the spontaneous bend-
FIG. 1. (color online). (a) Spontaneous bending of freshly
excised Hydra (plate- and rod-like) tissue fragments to quasi-
stable bent shape in several minutes. (b) Triple-layer struc-
ture of Hydra fragments: ectoderm cell layer (yellow), en-
doderm cell layer (light yellow), and intermediate soft ma-
trix (mesoglea). Two perpendicular supracellular actomyosin
bundles (red arrows) are formed on the basal sides of each
epithelial layer. Reproduced from Livshits et al. [4] with per-
mission from Elsevier.
ing happens very fast only in several minutes, it is rea-
sonable to assume that the bending is accompanied by
changes only in cell shape but not cellular rearrange-
ments or cell division and apoptosis [6]. Furthermore,
we propose that the spontaneous tissue bending is an
active process driven mechanically by the contractility
of the aligned, supracellular actomyosin bundles. An
active-laminated-plate model is constructed that corre-
lates the triple-layer structure and the supracellular con-
tractile bundles with the spontaneous bending of Hydra
fragments (see Fig. 1(b)). We predict that the bent shape
of plate-like Hydra fragments characterized by the spon-
taneous curvature tensor are mostly determined by their
anisotropy in both the supracellular actomyosin contrac-
tility and the elastic properties of each lamina layer, as
summarized in Fig. 2. The bending dynamics of rod-like
Hydra fragments propagates diffusively from the edges
arXiv:2210.11696v3 [physics.bio-ph] 19 Nov 2022
2
into the center (with the bent length being proportional
to the square root of time). Whereas, when the bending
is close to its final equilibrium (quasi-stable) shape, the
end-to-end distance decays exponentially with time to-
wards its equilibrium value. Moreover, we identify that
the interlayer frictional sliding is the dominant dissipa-
tion mechanism governing the spontaneous bending of
Hydra fragments in the first several minutes observed in
experiments [4].
Spontaneous curvature of Hydra tissue fragments.
To construct a continuum model for Hydra tissue frag-
ments, we first note a structural analogy between Hy-
dra fragments (with triple-layer structure) and compos-
ite laminated plates in material science [7,8]. Moreover,
we find that in typical regeneration experiments [4], the
lateral lengths of Hydra fragments are usually 100 µm
much larger than their thickness h10 µm. We then for-
mulate a thin active laminated-plate (ALP) model [9,10]
for Hydra fragments by following the classical thin lami-
nated plate theory [8] that extends the classical thin plate
theory [7] for mono-layer isotropic materials to multi-
layer orthotropic materials. In our ALP model, the bent
shape of a Hydra fragment is characterized by sponta-
neous curvature tensor and determined by minimizing
the deformation energy of the laminate fragment upon
internal active contraction applied by the two perpendic-
ular supracellular actomyosin bundles.
Technically, we treat the Hydra fragment as a lami-
nated plate consisting of two lamina layers (see Fig. 1(b)):
the ectoderm layer-1, and the composite endoderm-
mesoglea layer-2. In this case, we first consider Hydra
fragments with isotropic lamina, where the total bend-
ing energy density (per area) is found to be [9,10]
Fb=1
2Dp(c2
x+ 2νcxcy+c2
y)(M(1)
pcx+M(2)
pcy),(1)
with cxand cybeing the two principal curvatures of the
neutral surface at z=z0. Here νis the Poisson ratio and
Dpis the effective flexural stiffness. M(k)
pτ(k)
pz0and
τ(k)
p<0 (k= 1,2) are the active torques and contractile
forces generated by supracellular actomyosin bundles in
each of the two lamina layers, respectively. Note that
contrasted with the bending energy in a quadratic form
of principal curvatures in classical thin plate theory [7],
terms coupling active actomyosin torques linearly with
curvatures [11,12] also appear in Eq. (1), which result in
non-zero spontaneous curvatures.
Minimizing Fb=RdxdyFbgives the principal sponta-
neous curvatures [10]:
cx0 =c1νc2
1ν2, cy0 =c2νc1
1ν2,(2a)
in which ck=M(k)
p/Dpτ(k)
pz0/Dp(k= 1,2) char-
acterizes the contractility of the supracellular bundles in
each lamina layer with the neutral surface position given
by
z0=E(2)
p,eff h2
2E(1)
h2
1
2hE(1)
h1+E(m)
hm+E(2)
(h2hm)i.(2b)
Here E(k)
E(k)/(1ν2); E(k)(k= 1,m,2) are Young’s
modulus of the ectoderm, mesoglea, and endoderm, re-
spectively. h1and h2are the thicknesses of the two lam-
ina layers, respectively, with hmbeing the thickness of
mesoglea. The Poisson ratio νis assumed to be con-
stant (0 < ν < 1/2) through the fragment thickness.
E(2)
p,eff =E(2)
(E(2)
E(m)
)h2
m/h2
2, is the thickness-
averaged effective modulus of the endoderm-mesoglea
layer-2. Note that the concept of spontaneous curva-
ture has been used long time ago to represent the ten-
dency of lipids to curve in lipid membranes [13] and to
describe the spontaneous bending of uniformly-heated
bimetal plates [14], in which the driving forces are chemi-
cal heterogeneity and asymmetric thermal expansion, re-
spectively. In contrast, the spontaneous bending of tis-
sue fragments proposed in this work are driven by com-
pletely different forces due to contractile supracellular
actomyosin bundles.
FIG. 2. (a) Schematic illustration for the spontaneous bent
shape of Hydra fragments. The contour length, width, and
total thickness of the fragments are denoted by `c,w, and
h, respectively. (b) A schematic bent-shape diagram of Hy-
dra plates with different anisotropy in actomyosin contrac-
tility (measured by c2/c1) and in elasticity (measured by
E(k)
2/E(k)
1). Here ckcharacterize the contractility of supra-
cellular bundles; E(k)
1and E(k)
2are the two principal Young’s
moduli of each (k= 1,2) orthotropic lamina layer.
From Eq. (2) we conclude that the spontaneous bend-
ing (with non-zero spontaneous curvatures) of Hydra
fragments necessitates two basic conditions: the supra-
cellular actomyosin contraction (represented by non-zero
τ(k)
p) and the internal asymmetry in the elastic properties
and/or thicknesses of the two lamina layers (character-
ized by non-zero z0). Moreover, for elastically isotropic
fragments, we find from Eq. (2a) that the principal cur-
vatures and the equilibrium bent shape are mainly deter-
mined by the contractility anisotropy measured by c2/c1.
If ν < c2/c1< ν1, the Hydra fragments will bend spon-
taneously to elliptical cap shape; otherwise, they will
bend to saddle shape as shown in Fig. 2.
3
Next, for tissue fragments consisting of strongly
anisotropic lamina layers (for example, due to the pres-
ence of aligned thick actomyosin bundles in the two ep-
ithelial layers) we find that the spontaneous bending in
the two principal directions are almost independent [10],
and the neutral surfaces of the spontaneous bending lie
in different layers for bending along different directions:
in ectoderm and in endoderm for bending along the
ˆ
x-direction and ˆ
y-direction, respectively. In this case,
the two principal spontaneous curvatures are given by
cx0 c1>0, cy0 c2<0, that is, the fragments bend
spontaneously to be saddle shape (see Fig. 2(b)).
Recent experiments [4] show that (see Fig. 1(a)) Hydra
fragments bend spontaneously to a spherical cap shape
toward the inner endoderm side, that is, cx0 cy0 >0
and c1c2>0. From the bent-shape diagram in
Fig. 2(b), we find such cap-like bent shape corresponds
to the case of more-or-less isotropy in both elasticity and
contractility. Moreover, in this case, we find from Eq. (2)
that z0<0, which requires E(2)
p,eff < E(1)
(for h1h2).
This is ensured by the presence of the soft mesoglea
layer with E(m)
E(2)
, which can reduce the effective
endoderm-mesoglea modulus E(2)
p,eff to E(2)
(1 h2
m/h2
2)
that can be smaller than both the endoderm modulus
E(2)
and the comparable ectoderm modulus E(1)
[6].
Note that such mesoglea-softening mechanism is similar
to that of connecting a stiff spring to a soft spring in
series. Proper and stable inward tissue bending to endo-
derm side is essential for the formation of hollow Hydra
spheroid and the whole Hydra regeneration process.
Spontaneous bending of rod-like Hydra fragments.— If,
instead of a Hydra plate, one cuts a rod-like Hydra frag-
ment, the total bending energy density (per length) in
Eq. (1) reduces to [10]: Fb=1
2Drc2Mrcwith cbe-
ing the curvature of the neutral line at z=z0. Here Dr
is the effective flexural stiffness; τr<0 and Mrτrz0
are the active contractile force and active torque gener-
ated by supracellular actomyosin bundle in the ectoderm
layer-1, respectively. Minimization of Fb=RdxFbgives
the spontaneous curvature [10]: c0=Mr/Drτrz0/Dr,
and the neutral line position z0is given by the same form
as Eq. (2) if replacing E(k)
by E(k)wwith wbeing the
width of the Hydra rod.
Using DrEh3w,z0h, and noting that in typical
cell experiments [6,15]: τr/hw 0.1 kPa, h10 µm,
E1 kPa, we estimate the spontaneous curvature c0
1/100 µm1. Interestingly, for Hydra regenerating from
cell aggregates [3], the curvature cof the hollow Hydra
spheroids formed from an aggregate of a minimal num-
ber of Nc1000 cells [2,3] can be estimated to be the
same scale 1/100 µm1by calculating the surface area
of the spheroid, 4πc2NcR2
c, and using the cell size
Rc10 µm. Moreover, such cell-scale curvature is also
known to appear very often in many natural in vivo mi-
croenvironment [11], e.g., cylindrical shaped glands and
blood vessels [16].
Note that the supracellular contraction or the inter-
nal asymmetry in elastic and/or geometric properties are
generally non-uniform and hence the spontaneous curva-
ture can be different at different positions through the
fragments. In this case, some non-trivial periodic bent
shapes have been obtained as shown in Fig. S2 of SM [10].
Moreover, we would like to point out that the mechanis-
tic perspective of the spontaneous bending of tissue frag-
ments during morphogenesis conveyed in this work has
been proposed before [5,1719] and several classical the-
ories have been developed. Among the earliest theories of
this kind, Lewis proposed (1947) [17] a mechanical model
of epithelial sheets, consisting of brass bars, tubes, and
rubber bands. We discuss this model in SM [10] and com-
pare it with our ALP model for the spontaneous bending
shape of Hydra tissue.
In addition, during the tissue bending, interlayer slide
may occur between each cell layer and the intermediate
mesoglea matrix [15], and the fragment becomes incoher-
ent [20]. In this case, we neglect the in-plane contraction
and the total energy Fttakes the following phenomeno-
logical form [12,20]
Ft=Z`c/2
`c/2
ds Ys
22
sχsc+Dr
2(c˜c0)2.(3)
Here `cis the rod contour length, sdenotes the interlayer
slide or the misfit strain discontinuity between the two
lamina layers, and Ysis the stiffness for the interlayer
slide. ˜c0being the spontaneous curvature of coherent
fragments. χis the linear coupling coefficient. The equi-
librium bent state of the rod is then characterized by the
spontaneous curvature c0˜c0/(1 χ2/DrYs) and the
equilibrium slide s0 =χc0/Ys. Particularly, in the limit
of Ys→ ∞, we recover the case of coherent fragments
with c0= ˜c0and s0 = 0 where the strain is continuous
through the thickness.
Bending dynamics of tissue rods: effects of viscous dis-
sipation and interlayer frictional sliding. We now con-
sider the dynamic process of the spontaneous bending of
Hydra tissue rods in surrounding viscous fluids starting
from initial flattened state to the final equilibrium shape
as shown in experiments (Fig. 1(a)). The bending dy-
namics of long soft rods with non-zero spontaneous cur-
vature c0and contour length `c2πR0(R0=c1
0)
has been explored intensively in both theory and ex-
periments [21,22]. However, in typical Hydra regener-
ation experiments [4], Hydra rods are usually short with
`c2πR0. In this case, the total energy Ftof the lam-
inated Hydra rod is given by Eq. (3), and the bending
dynamics is driven by the relaxation of stored elastic en-
ergy in the initial flattened state. Furthermore, the dis-
sipation during the bending arises mainly from viscous
drag in the surrounding fluids and the interlayer fric-
tional sliding inside the fragments, as taken into account
4
by the dissipation function
Φ = Z`c/2
`c/2
ds 1
2ξv˙
r2+1
2ξs˙2
s.(4)
Here r(s) is the position vector of points (parameterized
by arc length s) on the rod, and the local curvature c
is given by its second derivatives [13]. ξvand ξsare the
viscous drag coefficient per rod length and friction coef-
ficient for interlayer sliding, respectively. Interestingly,
the interlayer frictional sliding has recently been found
to be able to facilitate the long-range force propagation
in tissues that usually have multi-layer structures [15].
We then use Onsager’s variational principle [23,24]
and minimize Rayleighian R[˙
r,˙s] = ˙
Ft+ Φ yielding a
set of highly nonlinear partial differential equation (e.g.,
Kirchhoff equations) [22]. However, here we will not solve
these nonlinear equations but carry out direct-variational
analysis [23,24] for the very initial bending stage near
the flattened state and the final bending stage close to
the equilibrium bent shape.
Initially near the flattened state, we neglect the effects
of interlayer slide and take a linear trial profile of local
curvature (see Fig. S4(a) in SM [10]), where the dynamic
bending process is characterized by one time-dependent
parameter: the bent length a(t) of the rod. Substitut-
ing the trial profile into Eqs. (3) and (4), we obtain the
Rayleighian R≈−1
3Drc2
0˙a+1
2ξva˙a2and its minimization
with respect to ˙agives
a2Drc2
0
3ξv1/2
t1/2,(5)
that is, the bending starts from the edges and propagates
diffusively into the center. Moreover, from Eq. (5) we
calculate the normalized end-to-end (ETE) distance ˜
`
(``eq)/(`c`eq) scaling as 1 ˜
`a3t3/2, where `
is the ETE distance with `eq being its equilibrium value.
Interestingly, although the linear trial profile has some
visible deviation from the simulated profile (as shown in
Fig. S4(a) in SM [10]), the scaling law predicted above
for ETE distance agrees well with simulation results in
Fig. 3(a) and is not sensitive to the form of trial curvature
profile; the same scaling is obtained by using a simpler
trial step-function profile of curvature. However, we note
that the initial diffusive bending process happens only in
a very short period as shown in Fig. 3(a). The bending
dynamics slows down quickly from the diffusive regime
to a subdiffusive regime with 1 ˜
`t0.9.
In the final stage of the bending dynamics close to
the quasi-stable bent state, we take the same strategy
as above and also choose a linear trial profile of the cur-
vature (see Fig. S4(c) in SM [10]), where the dynamic
bending process is described by the two time-dependent
parameters: the normalized curvature ˜cm(t) = cm/c0and
interlayer slide ˜s,m(t) = s,m/s0 in the rod center at
s= 0. Substituting the trial profile into Eqs. (3) and
(4), we obtain the Rayleighian Rand its minimization
yields
τ˙
˜cm= 1 (1 + Bcm+B˜s,m, τs˙
˜s,m= ˜cm˜s,m,(6)
where B=Ys2
s0/˜
Drc2
0characterizes the relative stiff-
ness of interlayer slide and out-plane bending with ˜
Dr
Drχ2/Ysbeing the normalized flexural stiffness, τ=
6ξvL/˜
Drc4
0and τs=ξs/Ysare the two characteristic time
scales associated with viscous drag and interlayer fric-
tional sliding, respectively. Note that Lis a nonlinear
function of rod contour length `c(changing from 0 to
order one; see its expression in SM [10]).
FIG. 3. Temporal evolution of the end-to-end (ETE) distance
˜
`for Hydra rods: (a) the initial bending starting diffusively
from the edges, and (b) the final bending relaxing exponen-
tially to the equilibrium shape. Universal scaling relations are
found for rods of different contour lengths π/2˜
`c3π.
We consider the following two limits of the dynamic
equation (6) that are particularly interesting and may
be relevant to the bending dynamics during tissue mor-
phogenesis and regeneration. Firstly, in the limits of ei-
ther coherent Hydra rods or incoherent Hydra rods with
small friction, we have τs1 and the viscous drag
from the surrounding fluids is the dominant dissipation
mechanism. In this limit, we find from Eq. (6) the nor-
malized ETE distance ˜
`(t) follows ˜
`exp (t/τ), which
have been justified for rods with various contour lengths
by numerical simulations using bead-spring model and
shown in Fig. 3(b). In addition, we have used bead-spring
model to numerically examine the bending dynamics of
Hydra rods under some different boundary conditions
(see Figs. S5-S7 in [10]). We find that the bending dy-
namics predicted above is very robust: the same scaling
laws (including the nonlinear contour-length dependence
of relaxational time τdue to L) are found for most dif-
ferent boundary conditions in both the initial diffusive
bending and the final relaxational bending processes.
Secondly, in the limit of incoherent Hydra rods with
large friction, we have τs1, we obtain from Eq. (6)
the ETE distance ˜
`(t) following the same exponential
form:
˜
`exp [t/τs(1 + B)] ,(7)
in which B 1 so that all energy terms in Eq. (3) are
comparable. That is, in either limits, the characteristic
5
time for the spontaneous bending of tissue rod is con-
trolled by the slower dissipative dynamics and the longer
time scale. Particularly for Hydra tissue rods, we can
estimate the magnitude of the two time scales as fol-
lows. Using ˜
DrEh3w,ξvη,wh,YsEhw,
and ξs=ξh2wwith ξbeing the interlayer friction coeffi-
cient [15], we obtain
τξv
˜
Drc4
0
η
Eh4c4
0
0.01 s, τsξh
E1 min,(8)
where we have taken typical parameter values measured
in cell experiments [6,15]: h10 µm, c01/100 µm1,
η103Pa ·s, E1 kPa, and ξ1010 Pa ·s/m.
Therefore, the spontaneous bending of Hydra rods lies in
the limit of τs1 and is characterized by τs1 min in
consistent with the time duration of initial spontaneous
bending observed in Hydra regeneration experiments (see
Fig. 1(a)) [4].
The proposal here on the spontaneous bending of Hy-
dra tissue fragments driven by contractile supracellu-
lar actomyosin bundles should be generically present in
a broad range of cell aggregates and tissue fragments
during tissue regeneration or morphogenesis during em-
bryo development. Our mechanical model of Hydra frag-
ments can be easily extended to study the morphogen-
esis of other tissues and to include the couplings be-
tween the organization of cytoskeleton and the deforma-
tion/curvature of the tissue [25]. The effects of the per-
meation of water or other small molecules on the dynam-
ics of tissue bending can be explored similarly by model-
ing the tissue fragments as active-laminated gels [26,27].
Additional aspects of the cell biology, such as cell divi-
sion/apoptosis and cell morphological changes [18,19], or
active behaviors such as migration and oscillations, could
be incorporated as well [17,28].
The authors thank Samuel Safran, Kinneret Keren,
Zhihao Li, Yonit Maroudas-Sacks, Lital Shani-Zerbib,
and Anton Livshits for fruitful discussions. X.X. is
supported in part by National Natural Science Foun-
dation of China (NSFC, No. 12004082), by Guang-
dong Province Universities and Colleges Pearl River
Scholar Funded Scheme (2019), and by 2020 Li Ka
Shing Foundation Cross-Disciplinary Research Grant
(No. 2020LKSFG08A). J. Su and H. Wang contributed
equally to this work.
E-mail address: xu.xinpeng@gtiit.edu.cn
[1] T. Fujisawa, Dev. Dyn. 226, 182 (2003).
[2] Y. Takaku, T. Hariyama, and T. Fujisawa, Mech. Dev.
122, 109 (2005).
[3] M. K¨ucken, J. Soriano, P. A. Pullarkat, A. Ott, and
E. M. Nicola, Biophys. J. 95, 978 (2008).
[4] A. Livshits, L. Shani-Zerbib, Y. Maroudas-Sacks,
E. Braun, and K. Keren, Cell Rep. 18, 1410 (2017).
[5] M. Krahe, I. Wenzel, K.-N. Lin, J. Fischer, J. Goldmann,
M. K¨astner, and C. F¨utterer, New J. Phys. 15, 035004
(2013).
[6] J. A. Carter, C. Hyland, R. E. Steele, and E.-M. S.
Collins, Biophys. J. 110, 1191 (2016).
[7] L. D. Landau and E. M. Lifshitz, Theory of Elasticity,
3rd ed., Course of Theoretical Physics, Vol. 7 (Pergamon
Press, Oxford, UK, 1986).
[8] J. N. Reddy, Mechanics of laminated composite plates and
shells: theory and analysis (CRC press, 2003).
[9] H. Wang, B. Zou, J. Su, D. Wang, and X. Xu, Soft
Matter 18, 6015 (2022).
[10] See the Supplementary Material [url].
[11] Y. Biton and S. Safran, Physical Biology 6, 046010
(2009).
[12] B. M. Friedrich and S. A. Safran, Soft Matter 8, 3223
(2012).
[13] S. A. Safran, Statistical thermodynamics of surfaces, in-
terfaces, and membranes (CRC Press, 2018).
[14] S. Timoshenko, J. Opt. Soc. Am. 11, 233 (1925).
[15] Y. Lou, T. Kawaue, I. Yow, Y. Toyama, J. Prost, and
T. Hiraiwa, arXiv:2107.03074 (2021).
[16] S. J. Callens, R. J. Uyttendaele, L. E. Fratila-Apachitei,
and A. A. Zadpoor, Biomaterials 232, 119739 (2020).
[17] A. ˇ
Siber and P. Ziherl, Cellular Patterns (CRC Press,
2017).
[18] E. Hannezo, J. Prost, and J.-F. Joanny, Proceedings of
the National Academy of Sciences 111, 27 (2014).
[19] J. Ackermann, P.-Q. Qu, L. LeGoff, and M. Ben Amar,
Eur. Phys. J. Plus 137, 1 (2022).
[20] D. Srolovitz, S. Safran, and R. Tenne, Phys. Rev. E 49,
5260 (1994).
[21] L. Tadrist, F. Brochard-Wyart, and D. Cuvelier, Soft
Matter 8, 8517 (2012).
[22] A. Callan-Jones, P.-T. Brun, and B. Audoly, Phys. Rev.
Lett. 108, 174302 (2012).
[23] M. Doi, Prog. Polym. Sci. 112, 101339 (2021).
[24] H. Wang, T. Qian, and X. Xu, Soft Matter 17, 3634
(2021).
[25] S. He, Y. Green, N. Saeidi, X. Li, J. J. Fredberg, B. Ji,
and L. M. Pismen, J. Mech. Phys. Solids 137, 103860
(2020).
[26] A. C. Callan-Jones and F. J¨ulicher, New J. Phys. 13,
093027 (2011).
[27] Z. Ding, P. Lyu, A. Shi, X. Man, and M. Doi, Macro-
molecules 55, 7092 (2022).
[28] M. Popovi´c, A. Nandi, M. Merkel, R. Etournay, S. Eaton,
F. J¨ulicher, and G. Salbreux, New J. Phys. 19, 033006
(2017).
摘要:

SpontaneousBendingofHydraTissueFragmentsDrivenbySupracellularActomyosinBundlesJianSu,1,2HaiqinWang,1,2ZhongyuYan,1andXinpengXu1,2,1GuangdongTechnion-IsraelInstituteofTechnology,241DaxueRoad,Shantou,Guangdong,China,5150632Technion{IsraelInstituteofTechnology,Haifa,Israel,3200003(Dated:November22,202...

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Spontaneous Bending of Hydra Tissue Fragments Driven by Supracellular Actomyosin Bundles Jian Su1 2Haiqin Wang1 2Zhongyu Yan1and Xinpeng Xu1 2.pdf

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分类:图书资源 价格:10玖币 属性:26 页 大小:2.26MB 格式:PDF 时间:2025-05-03

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