How does spaceflight affect tumor-bearing fruit fly hosts and their parasites?
Blade Shape: The kona mutant has an angular wing shape in contrast to wild-type's rounded wing blade (vertical arrows in D-F).
Background: Like humans, fruit flies (a model organism for spaceflight research) also exhibit immune system dysfunction in space. Despite decades of studies on fruit flies and wasps, little was known about how their immune systems interact with natural parasites in space. Drosophila parasitoid wasps modify blood cell function to suppress host immunity. In this spaceflight study (the Fruit Fly-03 Lab flown to the ISS on SpaceX-14), naive and parasitized ground and space flies from a tumor-free control and a blood tumor-bearing mutant strain were examined.
Main Findings: Surprisingly, the flies without tumors were more sensitive to space than the flies with tumors. Spaceflight increased immune gene activity and made tumors grow more in the flies. The wasps remained harmful in space, but some developed inheritable physical changes. These changes included "aurum" (altered wing color and veins) and "kona" (altered wing shape). Female wasps with two copies of the "kona" mutation could not lay eggs because of defective egg-laying organs.
Homozygous kona females with defective ovipositors (used for egg laying) how areas of compromised integrity or have branched ends (arrows) compared to the continuous ovipositors with sharp ends from wild-type control wasps.
