Talk:Carnegie Stages: Difference between revisions

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cell division with reduction in cytoplasmic volume, formation of inner and outer cell mass
cell division with reduction in cytoplasmic volume, formation of inner and outer cell mass

Revision as of 05:45, 13 April 2011

Carnegie Stage Table

Stage
Days (approx)
Size (mm)
Images
(not to scale, click image to see original)
Events
1
1
(week 1)

0.1-0.15

File:CSt1.gif

fertilized oocyte, pronuclei

2
2 - 3

0.1-0.2

Link=Carnegie_stage_2

cell division with reduction in cytoplasmic volume, formation of inner and outer cell mass

3
4 - 5

0.1-0.2

Link=Carnegie_stage_3

loss of zona pellucida, free blastocyst

4
5 - 6

0.1-0.2

attaching blastocyst

5
7 - 12
(week 2)
0.1-0.2

implantation

6
13 - 15
0.2

extraembryonic mesoderm, primitive streak

7
15 - 17
(week 3)
0.4
Link=Carnegie_stage_7

gastrulation, notochordal process

8
17 - 19
1.0 - 1.5
Link=Carnegie_stage_8

primitive pit, notochordal canal

9
19 - 21
1.5 - 2.5
[Stage9.htm File:CST9A.gif]

Somite Number 1 - 3neural folds, cardiac primordium, head fold

10
22 - 23
(week 4)
2 - 3.5
[Stage10.htm File:CST10A.gif]

Somite Number 4 - 12neural fold fuses

11
23 - 26
2.5 - 4.5
[Stage11.htm File:CST11.gif]

Somite Number 13 - 20rostral neuropore closes

12
26 - 30
3 - 5
[Stage12.htm File:CST12.gif]

Somite Number 21 - 29caudal neuropore closes

13
28 - 32
(week 5)
4 - 6
[Stage13.htm File:CST13.gif]

Somite Number 30leg buds, lens placode, pharyngeal arches

Stage 13/14 shown in serial embryo sections series of Embryology Program
14
31 - 35
5 - 7
[Stage14.htm File:CST14.gif]

lens pit, optic cup

15
35 - 38
7 - 9
[Stage15.htm File:CST15.gif]

lens vesicle, nasal pit, hand plate

16
37 - 42
(week 6)
8 - 11
[Stage16.htm File:CST16.gif]

nasal pits moved ventrally, auricular hillocks, foot plate

17
42 - 44
11 - 14
[Stage17.htm File:CST17.gif]

finger rays

18
44 - 48
(week 7)
13 - 17
Link=Carnegie_stage_8

ossification commences

19
48 - 51
16 - 18
[Stage19.htm File:CST19.gif]

straightening of trunk

20
51 - 53
(week 8)
18 - 22
[Stage20.htm File:CST20.gif]

upper limbs longer and bent at elbow

21
53 - 54
22 - 24
[Stage21.htm File:CST21.gif]

hands and feet turned inward

Stage 22 shown in serial embryo sections series of Embryology Program
22
54 - 56
23 - 28
[Stage22.htm File:CST22.gif]

eyelids, external ears

23
56 - 60
27 - 31
[Stage23.htm File:CST23.gif]

rounded head, body and limbs

Following this stage Fetal Development occurs until birth (approx 40 weeks)

(Source: Rothenburger and Gay, 1995. and others)

Carnegie Stage Table

Stage
Days (approx)
Size (mm)
Images
(not to scale, click image to see original)
Events
1
1
(week 1)

0.1-0.15

File:CSt1.gif

fertilized oocyte, pronuclei

2
2 - 3

0.1-0.2

[../../Notes/week1.htm File:CSt2.gif]

cell division with reduction in cytoplasmic volume, formation of inner and outer cell mass

3
4 - 5

0.1-0.2

File:CSt3.gif

loss of zona pellucida, free blastocyst

4
5 - 6

0.1-0.2

attaching blastocyst

5
7 - 12
(week 2)
0.1-0.2

implantation

6
13 - 15
0.2

extraembryonic mesoderm, primitive streak

7
15 - 17
(week 3)
0.4
[Stage7.htm File:CST7A.gif]

gastrulation, notochordal process

8
17 - 19
1.0 - 1.5
[Stage8.htm File:CST8.gif]

primitive pit, notochordal canal

9
19 - 21
1.5 - 2.5
[Stage9.htm File:CST9A.gif]

Somite Number 1 - 3neural folds, cardiac primordium, head fold

10
22 - 23
(week 4)
2 - 3.5
[Stage10.htm File:CST10A.gif]

Somite Number 4 - 12neural fold fuses

11
23 - 26
2.5 - 4.5
[Stage11.htm File:CST11.gif]

Somite Number 13 - 20rostral neuropore closes

12
26 - 30
3 - 5
[Stage12.htm File:CST12.gif]

Somite Number 21 - 29caudal neuropore closes

13
28 - 32
(week 5)
4 - 6
[Stage13.htm File:CST13.gif]

Somite Number 30leg buds, lens placode, pharyngeal arches

Stage 13/14 shown in serial embryo sections series of Embryology Program
14
31 - 35
5 - 7
[Stage14.htm File:CST14.gif]

lens pit, optic cup

15
35 - 38
7 - 9
[Stage15.htm File:CST15.gif]

lens vesicle, nasal pit, hand plate

16
37 - 42
(week 6)
8 - 11
[Stage16.htm File:CST16.gif]

nasal pits moved ventrally, auricular hillocks, foot plate

17
42 - 44
11 - 14
[Stage17.htm File:CST17.gif]

finger rays

18
44 - 48
(week 7)
13 - 17
[Stage18.htm File:CST18.gif]

ossification commences

19
48 - 51
16 - 18
[Stage19.htm File:CST19.gif]

straightening of trunk

20
51 - 53
(week 8)
18 - 22
[Stage20.htm File:CST20.gif]

upper limbs longer and bent at elbow

21
53 - 54
22 - 24
[Stage21.htm File:CST21.gif]

hands and feet turned inward

Stage 22 shown in serial embryo sections series of Embryology Program
22
54 - 56
23 - 28
[Stage22.htm File:CST22.gif]

eyelids, external ears

23
56 - 60
27 - 31
[Stage23.htm File:CST23.gif]

rounded head, body and limbs

Following this stage Fetal Development occurs until birth (approx 40 weeks)

(Source: Rothenburger and Gay, 1995. and others)

Embryo Stages

A standard system to study vertebrate embryos

PLoS One. 2009 Jun 12;4(6):e5887.

Werneburg I.

Paläontologisches Museum und Institut der Universität Zürich, Zürich, Switzerland. ingmar_werneburg@yahoo.de

Abstract

Staged embryonic series are important as reference for different kinds of biological studies. I summarise problems that occur when using 'staging tables' of 'model organisms'. Investigations of developmental processes in a broad scope of taxa are becoming commonplace. Beginning in the 1990s, methods were developed to quantify and analyse developmental events in a phylogenetic framework. The algorithms associated with these methods are still under development, mainly due to difficulties of using non-independent characters. Nevertheless, the principle of comparing clearly defined newly occurring morphological features in development (events) in quantifying analyses was a key innovation for comparative embryonic research. Up to date no standard was set for how to define such events in a comparative approach. As a case study I compared the external development of 23 land vertebrate species with a focus on turtles, mainly based on reference staging tables. I excluded all the characters that are only identical for a particular species or general features that were only analysed in a few species. Based on these comparisons I defined 104 developmental characters that are common either for all vertebrates (61 characters), gnathostomes (26), tetrapods (3), amniotes (7), or only for sauropsids (7). Characters concern the neural tube, somite, ear, eye, limb, maxillary and mandibular process, pharyngeal arch, eyelid or carapace development. I present an illustrated guide listing all the defined events. This guide can be used for describing developmental series of any vertebrate species or for documenting specimen variability of a particular species. The guide incorporates drawings and photographs as well as consideration of species identifying developmental features such as colouration. The simple character-code of the guide is extendable to further characters pertaining to external and internal morphological, physiological, genetic or molecular development, and also for other vertebrate groups not examined here, such as Chondrichthyes or Actinopterygii. An online database to type in developmental events for different stages and species could be a basis for further studies in comparative embryology. By documenting developmental events with the standard code, sequence heterochrony studies (i.e. Parsimov) and studies on variability can use this broad comparative data set.

PMID: 19521537 http://www.ncbi.nlm.nih.gov/pubmed/19521537

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2693928

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005887


A history of normal plates, tables and stages in vertebrate embryology

Int J Dev Biol. 2007;51(1):1-26.

Hopwood N.

Department of History and Philosophy of Science, University of Cambridge, UK. ndh12@cam.ac.uk Abstract Developmental biology is today unimaginable without the normal stages that define standard divisions of development. This history of normal stages, and the related normal plates and normal tables, shows how these standards have shaped and been shaped by disciplinary change in vertebrate embryology. The article highlights the Normal Plates of the Development of the Vertebrates edited by the German anatomist Franz Keibel (16 volumes, 1897-1938). These were a major response to problems in the relations between ontogeny and phylogeny that amounted in practical terms to a crisis in staging embryos, not just between, but (for some) also within species. Keibel's design adapted a plate by Wilhelm His and tables by Albert Oppel in order to go beyond the already controversial comparative plates of the Darwinist propagandist Ernst Haeckel. The project responded to local pressures, including intense concern with individual variation, but recruited internationally and mapped an embryological empire. Though theoretically inconclusive, the plates became standard laboratory tools and forged a network within which the Institut International d'Embryologie (today the International Society of Developmental Biologists) was founded in 1911. After World War I, experimentalists, led by Ross Harrison and Viktor Hamburger, and human embryologists, especially George Streeter at the Carnegie Department of Embryology, transformed Keibel's complex, bulky tomes to suit their own contrasting demands. In developmental biology after World War II, normal stages-reduced to a few journal pages-helped domesticate model organisms. Staging systems had emerged from discussions that questioned the very possibility of assigning an embryo to a stage. The historical issues resonate today as developmental biologists work to improve and extend stage series, to make results from different laboratories easier to compare and to take individual variation into account.

PMID: 17183461

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1885287

http://www.ijdb.ehu.es/web/paper.php?doi=10.1387/ijdb.062189nh