Chicken Lab Chicken Embryo Lab

Chicken Lab

Chicken Embryo Lab Report

A fate map can be used to track the progression of cell movements during chick embryo development. There are several potential uses for the information gathered and recorded on fate maps; the movement of cells and organs during development can yield a great deal of information regarding specifics of the species or genetic line as well as more general evolutionary information. In this technique, pioneered by N. Spratt and H. Haas (Journal of Experimental Zoology 103: 259-304 1946; 144: 139-158, 1960), the fate map is created by placing carbon markers in the blastoderm after it has been transferred to a petri dish. It is expected that significant movement of the carbon markers will occur during the experiment.

Materials and Methods

A chick blastoderm was explanted into an agar-containing petri dish following an incubation period. Glass needles were created y melting and stretching the ends of pipettes, and these needles were used to place very small amounts of carbon (charcoal) at three different spots near he primitive streak of the blastoderm. The embryo was at an early stage when it was marked, and after marking retained the faint "V" of the primitive streak with three clumps of carbon of varying size ranged in a perpendicular line to the point of the "V." The petri dish was returned to the incubator wth damp paper towels and was retrieved for further observation two days after the initial markings with charcoal were made.

Results

Following two days of continuing incubation, the blastoderm appeared to have undergone significant development. Several bubble-like structures of rather minute size had formed within the cellular material, the primitive streak was no longer visible at al,, and there was a clear circular definition of a darker area within the larger blastoderm. The carbon (charcoal) that had been added to the blastoderm had also undergone fairly significant changes, having been spread out over a wider area of the blastoderm. The three initial points of carbon deposit were still clearly visible and provided the highest concentration of carbon in the blastoderm, but these points had more regular edges and shapes more closely approaching true circles than they had following the initial deposit of the material. Specks of carbon, including some spots of fairly sizable, extended in the same line on which the initial deposits had been placed though spread much further towards the edges of the blastoderm.

Discussion