Genetic variation of morphological scaling in Drosophila

Morphological scaling relationships between the sizes of individual traits and the body captures the characteristic shape of a species, and the evolution of scaling is the primary mechanism of morphological diversification. However, we have almost no knowledge of the genetic variation of scaling, which is critical if we are to understand how scaling evolves. Here we explore the genetics of population morphological scaling relationships – the scaling relationship fit to multiple genetically-distinct individuals in a population – by describing the distribution of individual scaling relationships – the genotype-specific scaling relationships that are unseen or cryptic. These individual scaling relationships harbor the genetic variation that determines relative trait growth within individuals, and theoretical studies suggest that their distribution dictates how the population scaling relationship will respond to selection. Using variation in nutrition to generate size variation within 194 i..., Fly Stocks
All flies used in this study came from The Drosophila Genome Resource Panel (DGRP), a library of ~200 fully sequenced inbred isogenic Drosophila lineages that originated from a single outbred population (Mackay et al., 2012) collected from Raleigh, NC, USA. Flies were maintained on standard cornmeal molasses medium (Frankino et al., 2019) and maintained on a 12:12 light cycle at 22˚C and 75% humidity.
Starvation treatment
Drosophila egg collection, rearing, and phenotyping followed our established protocols (Stillwell et al., 2011, 2016; Frankino et al., 2019). For each DGRP lineage, females oviposited for three days. At 24h, 48h and 72h, eggs were collected, divided into lots of 50 and placed into vials containing 10ml of standard cornmeal molasses medium. This generated three age cohorts of flies (D0, D1 and D2, respectively). When third instar larvae from D0 began to pupariate, larvae from all cohorts were removed from the food and placed into empty food vials with a wet c..., All the data were analyzed using R and freely available R packages.