Applications

Ablation

Time course of development of a single wild-type embryo in which the muscle precursor cells, Cap and Cpp, were ablated (dorsal view). Despite the absence of ~1/3 of the body muscle (primarily posterior and dorsally positioned cells), intercalation occurs normally. Intercalating dorsal cells in A, B, C are indicated by arrows.

A) Start of intercalation.
B) Intercalation partially complete.
C) Intercalation complete.
D) Interior focal plane; arrowheads indicate undifferentiated ablated material. Times indicate amount of time elapsed from the beginning intercalation. Scale bar = 10 mm.

Cell Regeneration

First graphic shows ablation of spiral ganglion neuron. Second graphic shows related apoptotic death of its sensory inner hair cell in 6 day old organotypic culture of the newborn mouse cochlea 18 hours after single pulse laser beam injury.

FRAP

Yeast cells are labeled with Nuf2p::GFP to mark the spindle pole bodies and Ase1p::GFP in the mitotic spindle mid-zone. They are observed in DIC and fluorescence microscopy.
A) Metaphase spindle before elongation.
B) Telophase spindle at the end of Anaphase.
    Ase1p::GFP remains localized to the spindle mid-zone throughout mitosis.
C) Ase1p::GFP photobleached on the metaphase spindle.
D) Ase1p::GFP completely recovers within 20 minutes as the spindle elongate.

Haemostasis

Platelet thrombosis formation followed laser induced endothelical injury. FITC-anti-rabbit IgG and rabbit anti-CD41 were infused into the mouse via a jugular catheter. CD41 is located on platelets and FITC is associated with most platelets in the mouse circulation. Upon laser-induced endothelial injury of the arteriole with the MicroPoint Laser System, platelets become associated with the injured endothelial surface. Laser induced injury targeting the larger veins is shown near the base of the ear.

A) Before injury.
B) 30 seconds after injury.
C) 1 minute after injury.
D) 2 minutes after injury.
E) Vasculature of mouse ear.

Heat Shock Gene Promoter

Heat Shock Gene Promoter In Zebra Fish Individual cells in hsp 70-egfp transgenic embryos can be induced to express EGFP by targeting them with a MicroPoint Laser System. All panels are side views with anterior to the left and dorsal up. (A-C) Images of the developing ear in a living transgenic embryo 1 day after laser induction of an individual cell in the otocyst at 16 hpf (hours post fertilization), demonstrating that a single cell can be specifically induced and that the targeted cell appears undamaged.

A) DIC image.
B) Fluorescence image of the same field as A.
C) Superposition of A and B. Arrows indicate targeted cell.
D) Fluorescence image of a laser targeted CiD neuron in the spinal cord of a 33 hpf living transgenic embryo. The neuron was targeted at 15 hpf, before axon outgrowth, and has subsequently extended an axon several hundred microns down the spinal cord. The axon has branched and each branch is tipped with growth cones (arrows). The cell body is at level of somite 4 and growth cones at somite 9.
E) A DIC image of the tailbud at the stage tailbud cells were laser targeted at 16 hpf. Individual progenitor cells in the region posterior to Kupffer¡¦s vesicle (k) were induced.
F, G) DIC(F)and fluorescence of the same 36 hpf embryo in which one tailbud progenitor cell had been induced at 16 hpf. Arrows indicate the same region of both images. In this embryo, 6 EGFP-expressing somite cells were present in the posterior tail somites at 36 hpf. Scale bars, A-D, F, G, 20:m.

Early motor axons are retarded by laser-induction of Sema3A1 in muscle cells that they normally extend upon.
A) Side view of the trunk of a 22 hpf hsp70-egfpSema3A1myc embryo in which a muscle pioneer cell had been laser-induced to express egfpSema3A1myc (arrowhead) at 17 hpf.  It shows that the znp-1 labeled motor axon (arrow) had stopped upon exiting the spinal cord in the segment in which the anti-myc labeled, Sema3A1 - expressing muscle pioneer is located. The motor axons in the adjacent segments are normal.
B) Side view of the trunk of a 23 hpf hsp70-egfp embryo showing that the motor axon is normal following laser induction of EGFP in a muscle pioneer at 17 hpf. The induced muscle pioneer is labeled with anti-GFP. Scale bar, 20 :m.

Release of Caged Compounds

A) Labeled single cell of a germ-ring stage at 6 hpf zebrafish embryo (5 X magnification).
B) Labeled single cell of 40% epiboly 5 hpf zebrafish embryo.
C) Labeled .Tier one marginal cells of a 40% epiboly at 5 hpf zebrafish embryo.
D) Single (or two) labeled notochord cells of a 5-somite stage at 12 hpf zebrafish embryo (40X magnification).