Difference between revisions of "The Data Dump Paper"

Revision as of 14:46, 23 November 2011

Title

Abstract

Introduction

Question 1 - Is Light Modulation Ancestral in Cnidaria?

• Previous research indicates light modulates nematocyte firing in hydra. See Plachetzki nematocyte firing.

• Do cnidarians from other classes show a similar response to light, with respect to the modulation of nematocyte firing?

• In addition to the hydrozoan hydra, we tested light modulation of nematocyte firing in one scyphozoan (Aureila), and two anthozoans (Anthopleura and Haliplanella).

Question 2 - Why Light modulation?

H1: Pleiotropy

Molecular components are shared between chemo- and photo-reception. Do opsins artifactually affect the chemo-transduction cascade?

• Background
  • Known cnidarian phototransduction systems use G-alpha-s, which may stimulate adenylyl cyclase (AC) to decrease cAMP,
  • In Haliplanella, NANA may signal an unknown receptor that activates G-alpha-s, which may stimulate AC to decrease cAMP, which lengthens hair bundles to tune nematocyte firing to lower frequency vibrations.
  • Watson and Hessinger proposed that proline acts in opposition to NANA, and its receptor signals through G-alpha-i to shorten hair bundles and tune firing to higher frequency vibrations.

• Katia tested effects of light and mucin together on nematocyte firing.
• Federico tested whether light sensitivity involves G-alpha-i by using Pertussis toxin

H2: Light cues signal reliability of different feeding modes

• Bright light could favor transition to relying on photosynthetic symbionts.
• Dim light could signal nightfall, when zooplankton prey are more active

Methods

Results

Influence of Ptx (Gi inhibitor) in the presence of NANA and Proline

• In bright light, the Gi inhibitor Ptx seems to have no effect (could formally test that slope of Ptx concentration and firing rate is NSD than zero)

Discussion