|
 
- 积分
- 455
- 威望
- 455
- 包包
- 554
|

本帖最后由 细胞海洋 于 2010-11-30 12:27 编辑
/ ], ?6 ?# S5 }; q* d0 L7 B' ]) [ x
' {9 R* X* n- U3 S" c5 k4 b# gDevelopmental Genetics, or What Can Genetics and Genomics Tell Us About Evolution, Development, Stem Cells, Human Birth Defects, and Disease?
5 D0 }0 h6 [3 L8 V9 a! u7 ~' P( N0 g: u( p$ t* r5 g2 `" J* B& A
The ability of researchers to answer experimental questions greatly depends
" C" l) t% o$ u6 O1 \# h3 don the available technologies. New technologies lead to novel observations
4 G6 R- X6 n- f2 Q# W% hand field-changing discoveries and influence the types of questions that can2 [9 k* g6 w+ H8 n3 m; s3 e0 O, N
be asked. Today’s recently available technologies include sequencing and analyzing
9 {9 I4 I9 H$ U2 O0 x7 J F2 lthe genomes of human and model organisms, genome-wide expression
) I, O6 N+ T8 w& l9 Vprofiling, and high-throughput genomic and genetic analyses. The information
/ M e; Y% T4 w# vprovided by these approaches is enabling us to begin to understand the
, r u+ K$ S. V! Vcomplexity of many biological processes through the elucidation of gene regulatory
& z/ n. }( y v+ x- \" lnetworks, signaling pathway networks, and epigenetic modifications.- e* ~+ G6 u4 ]: W0 E6 O2 P
This book describes many lines of research that are being impacting by these: V+ ]8 |0 R2 o, `
new technologies, including developmental genetics and the related fields of
$ S- O5 L, w5 `0 ~& L( vclinical genetics, birth defects research, stem cell biology, regenerative medicine,. f2 I) C2 J! z
and evolutionary biology.
5 n5 T( r7 E4 `The field of developmental genetics, or the study of how genes influence) R4 T# F0 ^5 c6 c5 g" \
the developmental processes of an organism, has been influenced by new technologies! d3 R5 f0 G$ ^ K, v$ b+ b
and by interactions with other fields of study throughout its history.
% z3 I8 ?# M- Z+ n zThe concept of a genetic basis of development began in “modern” times at the$ l2 f7 j" ~# S* [
intersection of descriptive embryology and cytology. Modern histological1 x0 U- G6 O. v$ Z8 B! W/ S
techniques were developed in the mid-19th century, largely by Wilhelm His- ]$ p8 R6 N* N, M8 }. Y
so that he could study cell division in the neural tube, which enabled visualization
( H$ t0 m- U, o6 i# Xof the cell nucleus, chromosomes, and the discrete steps of mitosis.
, f- s( L, C/ M4 `Theodor Boveri cleverly applied these improved microscopic techniques to
% x! S. S; \. i! ]' ~: y5 ^transparent marine embryos to demonstrate that each parent contributes V4 Q0 M7 q* X# Y; _
equivalent groups of chromosomes to the zygote, and that each chromosome9 U6 b; w ^4 p& q. b) }. W' m
is an independently inherited unit. Importantly, he noted that if an embryo+ v5 Z h" l) ]) Q& n
contains the incorrect number or improper combination of chromosomes, it
- G5 L# ?3 ?8 rdevelops abnormally.# N! N5 P3 R3 y
However, many early embryologists rejected the idea that development is0 n+ d) F7 h& s4 d- N/ W
driven by prepackaged heritable particles because it seemed too similar to the. F" D( S3 p( N) R% E2 L+ R
idea of “preformation”: the concept that development is driven by predetermined$ z( s$ S! I f7 ]. w5 G' v
factors or “forces” (sometimes described in rather mystical terms).
/ j, W. P. O# z4 s/ B) BWilhelm Roux, an advocate of studying the embryo from a mechanistic point' d" T7 _; Q/ v8 N
of view, was a leader in the approach of manipulating the embryo with microsurgical7 P- x8 m. P* q$ |
techniques to elucidate cause and effects between component parts! V k) ?9 S8 q/ k7 k5 [3 ^
(experimental embryology). By using an animal model whose embryos were
7 h( ]6 s6 Q# `; a$ H zlarge, developed external to the mother, could be surgically manipulated with3 |4 O2 e' |) W
sharpened forceps and cultured in simple salt media (i.e., amphibians), he# ]4 l, G& _& F: G7 f
rejected the role of predetermined factors and demonstrated the importance
f8 y7 G8 [2 b* {/ O% c qof external (epigenetic) influences and cell–cell interactions in regulating
/ a" G% f1 n4 ~developmental programs. Experimental embryologists further refined their
& c s/ ]8 F1 b! z% L, rskills at dissecting small bits of tissue from the embryo, recombining them2 p. z8 p& {/ l; v
with other tissues in culture or transplanting them to ectopic regions in the
# @* A$ G* o* _+ [; X4 b$ a' pembryo. This work led to the invention of tissue culture by Ross Harrison
, {$ c1 _1 p8 P* {9 nand the discovery of tissue inductions by Hans Spemann.( d( [+ @5 J6 Z4 [4 o% P
While experimental embryology was thriving, T. H. Morgan founded the' s; Y( W9 H$ U( w0 W, {2 C0 G
field of Drosophila genetics. Also trained as an embryologist, Morgan was
7 ~0 k+ J& d9 e/ i; yskeptical of Boveri’s idea of heritable packets, and directed his studies towards0 R, x0 t% B& G1 N% z
understanding the principles of inheritance. For several decades, the two fields
6 D/ I$ Q: N6 H9 _( ~had little impact on one another. Interestingly, however, after a few decades of ]% u4 \; Y( ?- g) P0 K
study of the fruit fly, Morgan’s work supported the idea of discrete intracellular9 a* [1 N! i# R& ?5 W' U% U
particles that directed heritable traits, which he named “genes.” Nonetheless,
$ P9 p6 A0 H. o s0 B" gthe fields of experimental embryology and genetics remained fairly% R$ U9 h8 }/ t0 Q# k
separate entities with distinct goals and points of view. Embryologists were* ]) p% h7 d5 M9 O5 k" N- p1 K6 l' P/ j
elucidating the interactions that are important for the development of numerous
2 }# D% B% n5 k7 n2 f8 gtissues and organs, whereas geneticists were focused on the fundamentals v% d( H8 |/ \7 X) u
of gene inheritance, regulation of expression, and discovering the genetic
: A0 ^% @- K& _2 c+ J5 D3 Mcode. Indeed, elucidating the genetic basis of vertebrate development was
3 N F( [+ c6 V; {" idelayed until new technologies in molecular biology and cloning were devised.& C6 b5 j* e2 W3 V
From the field of bacterial and viral genetics came the techniques for cloning3 e! ^0 r) i, Y6 a
eukaryotic genes and constructing vectors for controlling expression. From
9 q' Z2 x s7 k/ Cthe classical genetic studies in fly and nematode came the rationale for mutagenizing
% _2 x# j% \7 ^) i) Pthe entire genome and screening for developmental abnormalities.
; n4 V# A3 t6 d. @# U! D! r8 F: CImportant regulatory genes were discovered in these invertebrates, and their
5 k& Z8 v( x1 ^( A8 s) p5 l9 @1 [counterparts were discovered in many other animals by homology cloning
: n0 s$ c/ i; M) I- \+ Fapproaches. Thus was born the modern field that we call developmental" O1 I2 V. `* d* U
genetics.
# p* v# f8 z; D! |! G! oAn important advance in the past decade is the demonstration that genes+ D# r; h+ ]0 b- e* B$ | o
that regulate developmental processes in invertebrate species have important
9 `' ]. M: M& O+ I7 Q4 I7 Jdevelopmental functions in vertebrates. The wealth of information concerning* M, Y9 w0 P" b7 K: b. r
the molecular genetic processes that regulate development in various animals
: f% a0 y" d2 V9 Ydemonstrates that developmental programs and biological processes are highly# I# k4 B! ]; q. ~/ N: m" s
conserved, albeit not identical, from yeast to human. Indeed, the Human( k1 H4 [! g4 \7 W1 Z! q3 s( X, ^4 O
Genome Project has made it possible to identify the homologues in humans
/ R1 Q I5 {) G) gand demonstrate that many of these regulatory genes underlie human developmental
( T& } o5 ] w$ T' W1 Odisorders and aspects of adult diseases in which differentiation processes
3 x' G. F$ C U2 f; c8 |6 U% K. hgo awry. Currently, researchers are studying the fundamentals of
6 A4 A1 p6 p Y1 j$ A9 N1 Jdevelopmental processes in the appropriate animal model and screening
) M: {( h( A5 O _' I7 B% fhumans for mutations in the genes identified by the basic research to be likely" ~" x1 P6 c8 r) d# I
causative candidates. Researchers are mutagenizing vertebrate animal models' g0 l4 T4 k* `% P+ O' p; t9 S/ X
and screening for mutants that resemble known human syndromes. This
1 _- j9 _5 I$ L9 n, ^& Ocross-fertilization of fields is also impacting concepts in evolutionary biology,1 {) H+ |/ b7 r0 \8 s; q
xii PREFACE
1 ?5 f2 h: F6 l' _7 {& `* o3 z4 fleading to a better understanding of “ancestral” species via gene expression
% ^ P) y3 Z/ F4 ~2 |profiles, and paradigms in stem cell biology in which naı¨ve cells may be directed
) K( n$ g# z( n: @& i ]$ P2 }- T4 \to “designer” lineages.2 t5 j. g# a+ j
Most recently, there have been significant technological advances in
5 v J% M7 s2 O3 l- u0 q" _genetic, genomic, and protein expression analyses that are having a major
7 [) S, X$ D$ ?' pimpact on experimental approaches and analytic design. The intersection of
3 E: d# H9 g- p2 q2 G/ u# M8 H( hdevelopmental biology with these technologies offers a new view of developmental$ K% P. @: p( L9 t F
genetics that is only beginning to be exploited. It is this new intersection8 q7 }0 }% O! e) G- L
at the onset of the genomic era that is the focus of this book. The book is
' O O) t3 @* B- {* U3 f: ~( B/ ?organized into sections focused on different aspects of developmental genetics.% i1 Z1 M2 @& }$ H
Section I discusses the impact of new genetic and genomic technologies on# P: z: P, U" l
development, stem cell biology, evolutionary biology, and understanding
# W, Y" @4 k: Y# n5 o+ ihuman birth defects. Section II discusses several major events in early embryogenesis,
% @0 W; _" h2 H- y4 Nfate determination, and patterning, including cellular determinants; e4 N* S; @% L5 E! Y- }. M. C
(Boveri revisited?), gene cascades regulating embryonic axis formation, signaling
& V- r5 m7 K! H' t0 Hmolecules and transcription factors that regulate pattern formation, and
5 i' M* |" A) U6 r7 d0 }the induction of the primary germ layers (ectoderm, mesoderm, and endoderm).8 {' g9 Z, s5 ?( @2 x
Section III describes the reorganization of the embryo via different
9 D" D& L$ O4 D4 Otypes of morphogenetic and cellular movements that result in the foundation
6 Z7 B2 b7 @- x6 r& H/ Mof organ systems, and discusses the many signaling and adhesion molecules
k6 n2 g1 b: Q8 x( bthat are involved in regulating these complex processes. The final three sections
3 t- r0 j& ]$ M% g# Bfocus on the signaling cascades and transcriptional pathways that regulate0 l3 G D, \) [* F% O
organogenesis in representative systems derived from the embryonic4 @2 I+ P% [" c5 i4 L$ O: N
ectoderm, mesoderm, and endoderm. These chapters illustrate how embryonic
2 ]1 M1 ^6 D" \. ?8 krudiments become organized into adult tissues, and how defects in these processes
9 J) S& a& G3 tcan result in congenital defects or disease. Each chapter demonstrates8 q$ e8 Q* W' P& a/ A/ e! P4 O4 I2 q
the usefulness of studying model organisms and discusses how this information
* ]9 ]) @5 G# S7 o2 e- {$ vapplies to normal human development and clinical disorders. Several& i0 v" i! {2 i$ R% J: w
chapters also discuss the utility of stem cells to repair damaged organs and& z7 |2 w: K, e/ `- U
the application of developmental genetics to the manipulation of stem cells+ i. a6 z0 `) D* f }: f* A, a
for regenerative medicine.' [ N V" Y. {: H$ y
The goal of this book is to provide a resource for understanding the critical. t/ J3 t( I( q0 z! X
embryonic and prenatal developmental processes that are fundamental to
g5 C3 z1 E2 G4 P: Z' H' s/ nthe normal development of animals, including humans. It highlights new" [: s. G7 o0 @5 |% |! G
technologies to be used, new questions to be answered, and the important
9 I6 x9 t+ D$ b2 a Q! vroles that invertebrate and vertebrate animal models have had in elucidating
5 c3 D- F: N5 ~8 a: C1 Jthe genetic basis of human development. Developmental genetics has reemerged
& g; ^) ?4 N) Wfrom its birth a century ago as a nexus of diverse fields that are using
: [$ [$ v" B, d% S+ C0 @the common language of gene sequence and function. This is influencing8 s1 O: d- U/ g5 Q" r/ |
what questions are posed and how the answers are used. New technologies+ L |; p6 J% A& G
are making it relatively easy to study gene expression and regulation at single9 Q3 V7 j: x6 [+ p6 A$ O+ |
cell, tissue, and embryonic levels. The conservation between the genomes
7 I/ \1 H8 T: c9 a. ]3 Qof species that are separated by vast evolutionary time encourages us to
! H4 l; V! C. a( F! `, Umore fully utilize animal models to gain important insights into the clinical' Z( y, e+ _& H
relevance of the animal model data. It is our hope that this book will stimulate
5 b# \* f& ]) M& ~% a1 Leven more cross-fertilization and interactions between evolutionary biology,
, |. W. O$ ~/ F, idevelopmental biology, stem cell biology, basic scientists, and clinical! g1 m% K- T. m8 r0 @" a3 j- w
scientists., Q) D' z0 D( E) e$ T8 u% k1 ]
I wish to thank all of the authors for contributing such exciting and
! ^1 s! g6 Q- l* w' O, xexcellent chapters, and Pat Gonzalez for keeping all of us on schedule.! u0 k2 H% E1 H. U" |' n, {3 b3 ?
2 B4 @+ t b3 O0 g. X |
附件: 你需要登录才可以下载或查看附件。没有帐号?注册
-
总评分: 威望 + 5
包包 + 20
查看全部评分
|