How do Mg2+ supplements affect fruit fly development?

Eamon GoucherWissahickon High School

TRIP Initiative at William Tennent High SchoolDr. Amanda Purdy, Ph.DDr. John Krais, Ph.D

Why is Magnesium (Mg2+) important?

J Clin Oncol. 2005 Jan 10:23(2):254-66.

• Cation- essential mineral in health Acquired primarily through diet

• Regulates blood pressure, maintains heartbeat rate, role in embryonic development• Cofactor (catalyst) in cell signaling pathways Ex. Ras oncogene- proliferation

Fruit Fly- Drosophila Melanogaster• Oregon R• Advantages

Fast reproductive rate- generations Studying cell proliferation/death Test organismal behavior through brain function

HypothesisIf Mg2+ in the fruit fly diet is increased, then the rate of development will increase

Fruit Fly Life Cycle

% Eclosion-Percent of pupae that become adults

Pupae Count-Number of fly “teens”

Embryo Genesis-Percent of embryos become larvae (”infants”)

Cell Death Analysis-Staining dead tissue

Negative Geotaxis Assay-Organismal behavior

Embryo Genesis• Quantify % Hatching• Parents exposure to food of varying concentrations for 1 week• Flies placed in ventilated container to reproduce

Grape Plate

Yeast

Mg2+ has no Effect on Embryo Development

% Hatching-Percent of embryos become larvae (”infants”)

Mg2+ has no Effect on Progression to Adulthood

% Eclosion-Percent of pupae that become adults

Mg2+ Causes Developmental Delay

Why is There a Delay?• Infertility?• Growth delay:

No change in eclosion, but reduced pupae

• Why would it slow down development?

0 mM 150 mM

Mg2+ Leads to Smaller Larvae

Cell Death Analysis• Dissect 3rd instar larval brains• 0.01% Methyl Blue staining

Live cells have no color Darker = more death

• Image Analysis Quantify death

The Process

Dissection setup Forceps restraining larvae

Trypan Blue staining Purification

Dissection Results• Darker = death

Control (0 mM Mg2+)

150 mM Mg2+

Mg2+ has no Significant Effect on Brain Cell Death

Negative Geotaxis Assay• Fly behavior as the result of Mg2+• Tests: thinking abilities, navigation• Tap flies, let move to top in 3 seconds

Mg2+ has no Effect on Fly Behavior

• Small sample size

Conclusion• Growth delay- larval stage

From magnesium supplement Possible causes:

1. Catalyzed alternate pathway2. Laxative3. Cell death?

Future Applications• Limit excess uptake of Mg2+- avoid growth delays Water filtration Avoid excess supplements

• Measure fly weight after exposure to Mg2+ Measure water weight throughout development

• Test plants with Mg2+ supplement Mg in Chlorophyll pigment

Acknowledgements• Dr. Amanda Purdy• Dr. John Krais• Lab partners- Alekhya, Cailyn, Ian, Jake, Jess, Liz, Pooja, and Subhanik• Elaine and Jerry Goucher• William Tennent High School• Mr. Ignacio Jayo

Thank you so much!