Model Organisms - Judkiewitz

Question 1

Briefly talk about the Danionella Translucida model in neuroscience.

Answer 1

The model has many advantages:

1. Small: adult size is around 35mm.
2. The smallest vertebrate brain (.6mm^3 10 times smaller than the zebrafish)
3. Transparent brain (optically accessible for imaging).

The fish reproduce by crevice spawning (spawning is a form of external fertilization, in which eggs and ova are released into the water). One female hatches eggs (sticky, hydrophobic and balloon-like) every 3-5 days, and they reach sexual maturity in 2-3 months. Eggs form clutches of 14-15 eggs.

They emit very loud sound (140 DB) used for tracking and male-male territory demarcation.

The auditory circuitry can be studied in this model using the advantage of in vivo Ca2+ imaging

Question 2

In what ways does this model resemble and differ from Zebrafish?

Answer 2

Resemble Zebrafish in 2 characteristics:

1. Genetic modification: the model’s genome has been sequenced (RNA-seq) using Illuina and nano pore, and now for genetic modification trans genesis and CRISPR/cas9 are used.
2. Complex adult behaviour:
   Shoaling (grouping of fish together), and schooling (moving of fish together).
   Behaviour study is better in adults while benefiting from the transparency characteristic is better during larvae stages.

they only differ from zebrafrish in that they are hard to breed.