RAMNe - Developmental table

Developmental table

I. Zygote period

Stage

Image

Slice

DIC

hpf

Simple description

Corresponding Stages in Ciona

1
Fertilized egg

0 hpf

Zygote, Fertilized egg

II. Cleavage period

Stage

Image

Slice

DIC

hpf

Simple description

Corresponding Stages in Ciona

2
Two-cell

1.2 hpf

The embryo composed of two cells.

3
Four-cell

1.5 hpf

The embryo composed of four cells.

4
Eight-cell

1.9 hpf

The embryo composed of eight cells.

5a
Early 16-cell

2.3 hpf

The embryo composed of 16 cells. Blastomeres is uncompacted in this stage.

5b
Late 16-cell

2.5 hpf

The embryo composed of 16 cells. Blastomeres has been compacted.

6a
Early 32-cell

2.8 hpf

The embryo composed of 32 cells. Blastomeres is uncompacted in this stage.

6b
Late 32-cell

3.0 hpf

The embryo composed of 32 cells. Blastomeres has been compacted.

7
44-cell

3.3 hpf

The embryo composed of 44 cells. The vegetal side blastomeres are bulging out.

8
64-cell

3.6 hpf

The embryo composed of 64 cells. Embryo has an almost circle shape from top view.

9
76-cell

4.0 hpf

The embryo composed of 76 cells. The embryo flattens on its vegetal side, in preparation for gastrulation.

III. Gastrula period

Stage

Image

Slice

DIC

hpf

Simple description

Corresponding Stages in Ciona

10
Initial gastrula,
112-cell

4.4 hpf

Gastrulation starts with A7.1 blastomeres, which is the center of invagination.

11
Early gastrula

4.8 hpf

The notochord has invaginated. The vegetal side of the embryo has a horseshoe shape.

12
Mid gastrula

5.3 hpf

The embryo has six-row neural pLate. The blastopore is located posterior and still open.

13
Late gastrula

5.7 hpf

The embryo elongates anteriorly. The blastopore is located posterior and nearly closed. The neural plate has more than 6 rows and a part of neural rows start to curve.

IV. Neurula period

Stage

Image

Slice

DIC

hpf

Simple description

Corresponding Stages in Ciona

14
Early neurula

6.2 hpf

Neural plate forms a furrow. The embryo has an oval shape. The furrow is not closed.

15
Mid neurula

6.7 hpf

The neural tube has formed along most of its length. The embryo has an oval shape. The A-line neural plate also forms a neural fold.

16
Late neurula

7.3 hpf

The neural tube closure starts in the posterior part. The embryo more elongates along A-P axis.

V. Tailbud period

Stage

Image

Slice

DIC

hpf

Simple description

Corresponding Stages in Ciona

17
Initial tailbud I

8.0 hpf

First indication of a separation between trunk and tail parts in this stage. The tail is not bent and boundary area between trunk and tail parts bulging out. The neural tube closure in the posterior territory finished and the neuropore move more anterior. Any notochord cells not finished intercalation.

18
Initial tailbud II

8.3 hpf

The tail is clearly distinguished from the trunk and begins to bend. The tail is shorter than the trunk. The neuropore is still opened.

19
Early tailbud I

8.8 hpf

The angle formed by trunk and tail is an obtuse angle and has the same length as the trunk. A few anterior notochord cells finish intercalation and the neuropore just close.

20
Early tailbud II

9.2 hpf

The tail bends about 90° and a half of notochord cells finish intercalation. The neuropore has closed.

21
Mid tailbud I

9.7 hpf

The tail is 1 1/2 times longer than the trunk and the angle formed by trunk and tail is an acute angle. Intercalation of the notochord cells is completed.

22
Mid tailbud II

10.1 hpf

The body curves circularly.

23
Late tailbud I

10.5 hpf

The pigmentation of the otolith starts. The tail most strongly curved in this stage and the tail length is twice as long as trunk.

24
Late tailbud II

12.1 hpf

The notochord vacuolation begins partially and palps formation is initiated by the anterior trunk epidermis thickening and bulging. Tail straightens in its anterior part.