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附上原文：. Y: \+ s; [/ Y- u/ l! o K
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( d0 ~4 M! s; U9 C4 t4 QARTICLES: S1 P; @) }* s0 Y& m" g5 @% [
----------------------) X. `8 I8 l1 M s- L& Z( V
Light-avoidance-mediating photoreceptors tile the Drosophila larval
9 T4 z: p2 _0 x `1 Qbody wall pp921 - 926
( N% v' _7 Z4 f* K" ^Light sensing outside the eyes is common in many animals but is
, Y7 Z: h% _/ y9 ~usually confined to specialized organs. Here, the entire body wall of - ?2 b# [ {7 E% ^
the fruitfly larva is found to be tiled with blue- and ultraviolet- % _, o) C& o& n+ ^/ J
light sensing neuronal dendrites, which are essential for the larva's
% I, e: A4 P9 l, q7 v# J; [innate light-avoidance behaviour. The phototransduction machinery used
* j0 C$ N/ E1 w" ^* [& mby these neurons is distinct from other Drosophila photoreceptor
7 |8 \# K" a; N: D# fmolecules but similar to a system recently identified in nematode
+ z. M: u! l) z9 o! c/ j; P. H" `6 nneurons.1 ?, w7 y m- i$ l; D) _
Yang Xiang et al.
# j4 J0 P h& I* ddoi:10.1038/nature09576
9 a; O* Z! F2 p7 X7 s/ o8 U4 r1 ZAbstract: http://www.nature.com/nature/jou ... bs/nature09576.html$ C$ y& I2 _, C
Article: http://www.nature.com/nature/jou ... ll/nature09576.html0 n- C& G, v- ?) k! A6 q) |
' z2 i0 R) x$ r+ yTRIM24 links a non-canonical histone signature to breast cancer pp927
3 Q5 E. }/ @* T# L. n4 ^- 932' S) x0 J# I7 N5 c& [
A crystal structure of the tandem PHD and bromodomain regions of the & } p, w" q4 k3 Y' p
transcription and chromatin regulator TRIM24 reveals combinatorial
! E9 Z' v! _" j; V( F8 Mrecognition of dual marks on the histone H3 tail. TRIM24 is involved
( W& E, ~) m4 r i! A( Pin activation of oestrogen-dependent genes and is aberrantly expressed
. L; N" s) @2 Pin breast cancer.
4 a( J' \2 z' ^Wen-Wei Tsai et al.* _+ X% ^' }0 q2 q: O
doi:10.1038/nature09542; G: p: R+ m1 Z
Abstract: http://www.nature.com/nature/jou ... bs/nature09542.html- g t" `2 Y8 x* V$ {
Article: http://www.nature.com/nature/jou ... ll/nature09542.html% P- E% m7 p! m; @9 t1 [; s0 I
, S. E/ Q+ M$ q7 I% q% cCRTC3 links catecholamine signalling to energy balance pp933 - 939; w8 ?# f. ]# C: T8 E0 c7 Y# d
β-adrenergic receptor signalling in adipocytes stimulates energy
5 D7 S3 }" ]4 Wexpenditure via cAMP-dependent increases in lipolysis and fatty-acid 9 [. ?+ }; O' a$ K/ B
oxidation, and this signalling mechanism is thought to be disrupted in , J& \, T+ H; |2 ^7 N
obesity. Here, the cAMP-responsive CREB coactivator Crtc3 is shown to : `7 }5 z9 D) C/ Q# l* [8 m
promote obesity in mice by attenuating β adrenergic receptor 8 z: I, s2 B0 S O7 g8 j3 _& A. P$ `
signalling in adipose tissue. P, [1 S: y8 a7 J3 m3 n+ w
Youngsup Song et al.
6 W n- _' W/ ~) `# H+ L5 Mdoi:10.1038/nature095648 W0 j' U9 c# w
Abstract: http://www.nature.com/nature/jou ... bs/nature09564.html
1 u1 j* a: o2 ?& N* WArticle: http://www.nature.com/nature/jou ... ll/nature09564.html
5 o: z# L- d- a5 z j ]
- C" m1 U/ M$ W4 O# }; d9 Q----------------------; C, s- I& X( n
LETTERS
4 u3 L+ e& E2 s8 S ?( \----------------------
~; c9 L' m: z" n* r8 J/ n4 V. OA substantial population of low-mass stars in luminous elliptical & X' b+ `; `3 [+ O
galaxies pp940 - 942
& p' i( d4 _! c- S! _The stellar initial mass function describes the mass distribution of
* r& _8 @8 o, X/ G; s1 Astars at the time of their formation. This study reports observations
0 Z. Y0 {+ l8 c1 k! e3 rof the Na I doublet and the Wing-Ford molecular FeH band in the # T: u: Q1 Y) M
spectra of elliptical galaxies. These lines are strong in stars with
' b7 q P. a- w9 ]1 i, |7 f3 Nmasses6 L' {& ~- a b3 @
Pieter G. van Dokkum and Charlie Conroy
- r) n5 y A* P, `( Ldoi:10.1038/nature09578- H O |' }7 V* F0 p4 a
Abstract: http://www.nature.com/nature/jou ... bs/nature09578.html
- |5 v# N$ r5 s5 o. ZArticle: http://www.nature.com/nature/jou ... ll/nature09578.html
6 f7 ~ H2 K e6 ^/ N! k8 s1 t3 |# H; E
Origin of Saturn’s rings and inner moons by mass removal from a lost * t; ?- r O! {( R1 V7 p
Titan-sized satellite p943
P& j6 b( r# e5 W2 [* ], pSaturn's rings are more than 90–95% water ice, which implies that
# l! s. F+ _3 o" D- K- h+ A/ W9 Ninitially they were almost pure ice because they are continually . P4 O$ u) z* p
polluted by rocky meteoroids. Saturn has only one large satellite,
' g' @; ^! a! v0 ]; T2 A: _5 ATitan, whereas Jupiter has four large satellites; additional large
4 G, z- v- }. K0 c- Rsatellites probably existed originally but were lost as they spiralled 7 l# H: O8 X' A5 p& @6 u
into Saturn. Now, numerical simulations of the tidal removal of mass * ^# w' L l) [4 y/ F6 a; n; w
from a differentiated, Titan sized satellite as it migrates inward * ~! z) H4 e4 f% T3 u
towards Saturn are reported. Planetary tidal forces preferentially 8 X( z+ W ^/ {; t9 K
strip material from the satellite's outer icy layers, while its rocky
+ N7 C! i% k: Z% Ucore remains intact and is lost to collision with the planet. The + U; m% J; w) m
result is a pure ice ring.* `) j& f H9 O$ \( L# ^1 j5 ?& H5 m
Robin M. Canup
# Q/ o$ ~- H z% X# ~doi:10.1038/nature09661% E& Z: ^( D, |- B- A! n# j
Abstract: http://www.nature.com/nature/jou ... bs/nature09661.html
$ o4 g& O9 ]$ j3 vArticle: http://www.nature.com/nature/jou ... ll/nature09661.html1 h! R2 l% X! j" ]% h w
& e) i0 r2 r- ^: h# F* m
Pleats in crystals on curved surfaces pp947 - 951
% {' x5 ~0 F- U7 j) R; w8 M4 f4 fHexagons can easily tile a flat surface, but not a curved one. Defects
- b4 h" D6 v; s- p1 R6 rwith topological charge (such as heptagons and pentagons) make it 9 ~6 f* n0 H+ | C& T! N" ~, `
easier to tile curved surfaces, such as soccer balls. Here, a new type
2 B- W0 C- Z- o. ^5 f- y" [9 kof defect is reported that accommodates curvature in the same way as 7 _/ I' J( \' m( c7 f
fabric pleats. The appearance of such defects on the negatively curved
W3 i( M7 ]8 rsurfaces of stretched colloidal crystals are observed. The results
4 W9 t7 R; D( E; Owill facilitate the exploration of general theories of defects in 6 d, s( F" ?1 Y6 P( Q
curved spaces, the engineering of curved structures and novel methods
' t& ]/ M' s4 t) q, W, @for soft lithography and directed self-assembly.
( V. N2 F( q( a4 |4 cWilliam T. M. Irvine, Vincenzo Vitelli and Paul M. Chaikin3 w+ x- ~4 K5 c/ V: M$ L, K
doi:10.1038/nature09620( ?# o3 f3 }5 F2 {# J3 [
Abstract: http://www.nature.com/nature/jou ... bs/nature09620.html
3 Z" O, K7 J$ I- g8 hArticle: http://www.nature.com/nature/jou ... ll/nature09620.html1 A+ q4 L L5 A3 m8 P4 t/ L) J: v- b
% h x0 P' f3 R/ H9 `5 f, ^. F* ~, mTidal dissipation and the strength of the Earth’s internal magnetic ( \" S. V u6 C1 c, L
field pp952 - 9547 X& j! K) q# R0 p9 |' n
Here, an indirect estimate for the magnetic field strength within the
, ~: P- T' Y0 `' n4 @Earth's core from measurements of tidal dissipation is presented.
: L9 } c2 D& n2 j2 z& OPreviously reported evidence of anomalous dissipation in the Earth's
8 \% |6 e, |0 P% unutations can be explained with a core-averaged field of 2.5 mT,
) q# k! C7 B/ S/ g, x8 g! ?4 beliminating the need for high fluid viscosity or a stronger magnetic - T7 ]* E; P a
field at the inner-core boundary.
9 H/ V; _9 J$ K: b' B, p' a) M2 T. LBruce A. Buffett
8 Q5 \( A! b6 Y5 E. x1 @8 Ndoi:10.1038/nature09643
! A4 F4 e- L* `4 DAbstract: http://www.nature.com/nature/jou ... bs/nature09643.html9 W+ s. t# n( y/ W1 L
Article: http://www.nature.com/nature/jou ... ll/nature09643.html- ^# F3 f( g2 h* Z* w
v3 n) d2 l* l) p3 b) n; S7 e
Greenhouse gas mitigation can reduce sea-ice loss and increase polar
8 p- z4 H m# A' K# ebear persistence pp955 - 958" ]" w' Y3 J0 Y, @
The dramatic loss of Arctic sea ice with climate change has led to the
2 ~" j! x, }& T/ c, Wprediction of a tipping point beyond which ice loss is irreversible / H, |' P; X I& ^, z' S
and polar bear habitat will be catastrophically lost. By contrast,
* H, u# G5 I( \, t. K* Athis study shows a linear relationship between temperature and sea-ice
; |4 G% I4 B: G4 _$ Pcoverage that overcomes the albedo effect that would cause a tipping
5 a& j' q; H/ G ]5 H+ vpoint. As a result, reducing greenhouse gas emissions can have a
; l1 \& s# F% ^, P% s$ g q& ]positive effect on polar bear populations.8 z5 Q+ K. T; E+ v- s
Steven C. Amstrup et al.
1 X. D7 v0 i, D4 h) ]" Ndoi:10.1038/nature09653; P4 I% K2 }# T' ]' Y1 g
Abstract: http://www.nature.com/nature/jou ... bs/nature09653.html
* ^; s+ }, N( E- q# G$ V$ `Article: http://www.nature.com/nature/jou ... ll/nature09653.html
6 `! X% e* k$ D! v
% Z4 |" m/ k4 z' L1 k5 y0 a! XIntercalation of a new tier of transcription regulation into an 1 Z5 J+ w. p# s. D& ^+ ~
ancient circuit pp959 - 9639 }) x8 ~8 F7 \* M% N. X$ h8 z, d
How new phenotypes can be introduced during evolution without losses
7 E% Z w; `& s# X; s; y# p6 ~1 ~of fitness remains largely unexplained at the molecular level. By
, ^3 p4 q- e% V& [comparing the molecular details of a well known process — mating type ) \& a5 b& D2 `, ~8 S
determination — across a large diversity of yeast species, the ' X" \7 f6 w( ]% j& Q
network rewiring event of the intercalation of a new level of gene ! ]4 F6 i0 b( M- T4 Q1 C2 m ?( H0 A
transcription control into an ancient regulatory circuit is shown,
0 M! Y5 P5 Q* n8 nwhich allowed for the creation of a new phenotype — taking food 9 x1 N7 i) M- S" S" D9 c
availability into account when deciding to mate.1 Y& ]5 C7 K+ L
Lauren N. Booth, Brian B. Tuch and Alexander D. Johnson0 \' b9 j1 v: P0 f3 V
doi:10.1038/nature095609 B/ \& [. I6 {( N( G& U
Abstract: http://www.nature.com/nature/jou ... bs/nature09560.html/ D5 h. i9 _/ Z
Article: http://www.nature.com/nature/jou ... ll/nature09560.html# [( {- q8 X8 `0 G& }- x
$ a( `1 a7 e8 Y+ o0 j4 rNoise correlations improve response fidelity and stimulus encoding
+ }6 Z% W8 x. s% C+ rpp964 - 967; k- d/ y: x' i2 L$ H
This study introduces a novel recording technique for simultaneously
5 J9 J4 R0 G; D+ S# r2 z; Q7 ~measuring excitatory and inhibitory conductances of retinal ganglion 3 L% Z5 H$ F* R3 r
cells to show that excitatory and inhibitory inputs are strongly
- w5 A' Q. ~) S b. m: }6 bcorrelated, thereby cancelling each other. Furthermore, dynamic clamp & |# d" F( Y3 u! ?! R3 r
is used to introduce these conductance changes into the cell with or ) M( k; B5 T' K# a' \3 ~: ?+ p" L
without correlations, and it is found that, as predicted by
! \* @3 {3 i9 k, h: I6 btheoretical work, correlations significantly increase reliability of
" J( V& g( A6 j" c Tthe spiking response.7 f# l" F @6 |2 o) S$ Z( ^
Jon Cafaro and Fred Rieke
# U0 B: D; N0 |3 ]7 `/ S$ F' ^+ [doi:10.1038/nature09570
$ A+ c8 Z; S V. ?Abstract: http://www.nature.com/nature/jou ... bs/nature09570.html) \- x2 J3 y# u% b: W+ D" N
Article: http://www.nature.com/nature/jou ... ll/nature09570.html) H( c; ~5 z6 h3 {4 b8 {; ] S
" v" [" y, w4 I% v# @# E! G1 `7 Q) ]
COT drives resistance to RAF inhibition through MAP kinase pathway 4 ~0 r3 b" @' O. w/ e W+ e: S/ U
reactivation pp968 - 972, Y( o2 R8 Y5 b1 ?* B- e
Recent data from early clinical trials in melanoma patients carrying 0 I, y5 t. k8 h6 L$ ^, I' t
mutations in the B-RAF gene have shown promising results with the B- 1 |% a: n7 U2 A" _ X
RAF kinase inhibitor PLX4032; however, many patients eventually + t9 n M2 G {, z0 l" B; K/ Z! M. ?
develop resistance to this treatment. Two papers now uncover possible % @4 E( y" ~, R x: i+ e# \
mechanisms of resistance to PLX4032. One paper shows that upregulation
& w( x* a0 x: b. b- hof MAP3K8 (which encodes COT) can confer resistance of melanoma cells
& K3 P% g1 l, P$ D) _/ yto B-RAF inhibitors, whereas another paper found that melanomas can # j2 ]% l! O/ K w; `& h) Q3 i
acquire resistance due to mutations of N-RAS or increased expression 8 C- [0 L/ Z; @* }+ m
of PDGFRβ. Each of these resistance mechanisms seems to apply to at $ J1 M' ]) \% u
least some patients on recent PLX4032 trial, whereas, surprisingly, so - ~ `" S8 O+ Q2 M7 M- F
far no secondary B-RAF mutations have been observed.$ ^- P/ v5 Q1 a8 O1 A2 s
Cory M. Johannessen et al.
/ W4 K% O7 R' v( b( G9 @doi:10.1038/nature096274 U0 A1 n+ N: |- ?% ~
Abstract: http://www.nature.com/nature/jou ... bs/nature09627.html9 G0 h$ k( g+ a+ \6 i# ?5 c
Article: http://www.nature.com/nature/jou ... ll/nature09627.html
7 I* |* V- S% C' Q, d# r$ _/ f
; \3 P6 Y/ Q; U+ }0 ]Melanomas acquire resistance to B-RAF(V600E) inhibition by RTK or N- # n4 P5 b: \- r# F9 z9 k
RAS upregulation pp973 - 977
7 g+ r7 X# U) l6 Y7 IRecent data from early clinical trials in melanoma patients carrying
! h* u# U. u* `/ a; J( omutations in the B-RAF gene have shown promising results with the B- 2 t) l4 W- @- O W/ A) v
RAF kinase inhibitor PLX4032; however, many patients eventually
, Q4 n# ]% F2 G! y5 Mdevelop resistance to this treatment. Two papers now uncover possible
8 S& y% V2 C/ T5 r* A8 bmechanisms of resistance to PLX4032. One paper shows that upregulation ! g3 _: _$ ^# m7 _
of MAP3K8 (which encodes COT) can confer resistance of melanoma cells
" {% Q! g) r. ^, v' N+ qto B-RAF inhibitors, whereas another paper found that melanomas can ) r$ b" c' K, a/ F0 M
acquire resistance due to mutations of N-RAS or increased expression
1 [4 Y. Q& n) P1 }* H7 Jof PDGFRβ. Each of these resistance mechanisms seems to apply to at
6 } G; ^- O( o2 L& Wleast some patients on recent PLX4032 trial, whereas, surprisingly, so ' r8 K3 [' i* w5 l
far no secondary B-RAF mutations have been observed.
( T" v$ p8 A. WRamin Nazarian et al.
4 |& J* g- w, M$ p- d' Ddoi:10.1038/nature09626) h. O9 K/ A( B# l4 A2 E3 @0 C1 e
Abstract: http://www.nature.com/nature/jou ... bs/nature09626.html
6 f, Q3 [& J3 hArticle: http://www.nature.com/nature/jou ... ll/nature09626.html% d7 H9 G- Q3 j
8 g( B3 X% x, u& PCrystal structure of bacterial RNA polymerase bound with a
s; _5 N+ `3 ntranscription inhibitor protein pp978 - 982% k) {, g# T1 z) j
A crystal structure of bacterial RNA polymerase (RNAP) bound to the 5 m+ M) e$ ~4 p$ }
transcription inhibitor Gfh1 reveals the mechanism of inhibition by 8 S0 q0 j5 v9 ~7 J
Gfh1 and an alternative ratcheted state of RNAP.+ f2 W, u: _* |4 {6 D
Shunsuke Tagami et al.' l. d1 Z) j, Y4 ]
doi:10.1038/nature09573* I: r2 p# y ?) d& v
Abstract: http://www.nature.com/nature/jou ... bs/nature09573.html
( C y! e8 k) X- sArticle: http://www.nature.com/nature/jou ... ll/nature09573.html) ~; O. f4 q* c/ ]7 l% C K
) i) {" M9 A4 R! _7 s& T7 p0 t+ HSingle-molecule imaging reveals mechanisms of protein disruption by a : ?$ M( G ~0 `" c9 ]
DNA translocase pp983 - 987
- r8 |) ^' ?; W" M$ aProtein machineries that move along the DNA, such as DNA polymerases : t0 c" l4 v( ~1 ]8 [
and helicases, will necessarily encounter other bound proteins
/ d4 g) L+ p5 j; A) s' V! `interacting with specific sites. Using 'curtains' of labelled DNA, & R) n0 ^0 ]( j2 C4 h. t
this study measured whether such bound proteins interfere with the ) G9 i- L% K* D/ S( Y
activity of the bacterial DNA translocase RecBCD. The translocase is 7 ?$ \) v) T; L" W
able to push the proteins over nonspecific sites for thousands of base
/ G! L, j1 Q) a4 P! V Xpairs before they are displaced.: C9 r2 X. E' O% F: s% m) z
Ilya J. Finkelstein, Mari-Liis Visnapuu and Eric C. Greene" j# P c9 [0 p- N6 k
doi:10.1038/nature09561
& h% `1 {; k0 y* \Abstract: http://www.nature.com/nature/jou ... bs/nature09561.html* J1 ^5 W* R7 a' d# P$ Y; [( q6 P
Article: http://www.nature.com/nature/jou ... ll/nature09561.html. i0 J! e9 \" w3 r' W: H3 L
4 i+ v4 X) M; g% t
The mechanism of sodium and substrate release from the binding pocket
# S7 o, M7 t tof vSGLT pp988 - 991
4 b* ^, d$ B3 s$ U) `Here, a comprehensive study of the sodium/galactose transporter 9 P7 s! H9 r3 O0 G, l
(vSGLT) is presented, consisting of molecular dynamics simulations, & n. ]4 l% B* L7 {( E
biochemical characterization and a new crystal structure of the + d2 C" I$ B5 S! K+ f9 f8 Z
'inward-open' conformation. These experiments show that sodium exit
+ I# q1 T' ?- K0 Z& u7 _causes a reorientation of transmembrane helix 1, opening an inner gate , J' ?$ i; A0 N9 F
required for substrate exit, while also triggering minor rigid-body 7 \2 N5 ~2 f" R% I8 r' Z
movements in two sets of transmembrane helical bundles. This cascade
7 p0 z! R% W0 p. c' Q& Xof conformational changes is responsible for the proper timing of ion
2 j( T$ |2 Y% N, @2 cand substrate release. |
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发表于 2010-12-16 16:18
非常好 谢谢楼主
发表于 2010-12-17 10:30
