Precisely Placed

Vein patterns in the wings of developing fruit flies never vary by more than the width of a single cell.

Jyoti Madhusoodanan
Aug 31, 2014

RIGID CONSTRUCTION: The wing vein patterns of two flies deviate from one another by a width no greater than half a cell.THOMAS GREGOR


The paper
L. Abouchar et al., “Fly wing vein patterns have spatial reproducibility of a single cell,” J R Soc Interface, 11:20140443, 2014.

The embryo
Multicellular organisms faithfully re-create the patterns of complex body structures from one generation to the next. Thomas Gregor’s lab at Princeton University previously showed that the initial body plan of three-hour-old fruit fly (Drosophila melanogaster) embryos varied, from one embryo to the next, by a total width no greater than half of a cell. This led Gregor to wonder whether wing patterns, which develop in 10-day-old flies, are just as precise.

The wing
Gregor and his colleagues used computer analysis and superimposition to measure and compare wing vein patterns in fruit flies. Even when grown at different temperatures, genetically similar flies had as little variation between two flies’ wings as between the left and right wings of a single fly. And genetically less-similar flies’ wings differed by no more than one cell’s width, suggesting exquisitely precise developmental control over vein patterns. “At every single step, we are at the precision of one half to one cell, so no [additional] error-reducing mechanisms [are] necessary,” says Gregor.

The extended pattern
Confirming these data among fruit fly lines with known mutations in wing patterns is crucial, says evolutionary geneticist Ian Dworkin of Michigan State University in East Lansing. If the data hold, it would point to “a remarkable amount of communication between the two sides of the body,” he says. “It would mean development is really incredibly precise.”

The bigger picture
Understanding this reproducibility between and within individuals could help synthetic biologists, says Gregor. “If we want to build biological machines we need to understand how [such] systems ensure reproducibility and precision.”

Correction (September 16): In the original version of this article we mistakenly identified the flies under study as embryos, when in fact they were adults. The Scientist regrets the error.