The association between inversion In(3R)Payne and clinally varying traits in Drosophila melanogaster

Abstract

In Drosophila melanogaster, inversion In(3R)Payne increases in frequency towards low latitudes and has been putatively associated with variation in size and thermal resistance, traits that also vary clinally. To assess the association between size and inversion, we obtained isofemale lines of inverted and standard karyotype of In(3R)Payne from the ends of the Australian D. melanogaster east coast cline. In the northern population, there was a significant association between In(3R)Payne and body size, with standard lines from this population being relatively larger than inverted lines. In contrast, the inversion had no influence on development time or cold resistance. We strengthened our findings further in a separate study with flies from populations from the middle of the cline as well as from the cline ends. These flies were scored for wing size and the presence of In(3R)Payne using a molecular marker. In females, the inversion accounted for around 30% of the size difference between cline ends, while in males the equivalent figure was 60%. Adaptive shifts in size but not in the other traits are therefore likely to have involved genes closely associated with In(3R)Payne. Because the size difference between karyotypes was similar in different populations, there was no evidence for coadaptation within populations.

Genomic Differentiation Between Temperate and Tropical Australian Populations ofDrosophila melanogaster

“…Interestingly, many body-size candidate genes revealed by our analysis are located on chromosome arm 3R, which is consistent with previous genetic analyses showing that most of the body-size variation associated with the Australian cline is inseparable from In(3R)P in mapping crosses (Rako et al 2006(Rako et al , 2007. Our dataincluding evidence of extensive recombination between standard and In(3R)P arrangements-suggest that the differentiated genes that are located on 3R are particularly promising targets for investigating the genetic basis of body-size variation in D. melanogaster.…”

Latitudinal and cold-tolerance variation associate with DNA repeat-number variation in the hsr-omega RNA gene of Drosophila melanogaster

“…Larger body size (often approximated as wing size) is recognized as an adaptation to cold-temperature environments and clinal variation in body size (Avis et al, 1997) has been associated with clinal variation in In(3R)P (Rako et al, 2006) that is in linkage disequilibrium with hsr-omega-L/S (Anderson et al, 2005a). A positive hsr-omega-fr allele frequency association with wing area was evident (Table 2).…”

Mapping Regions Within Cosmopolitan Inversion In(3R)Payne Associated With Natural Variation in Body Size in Drosophila melanogaster

“…The cosmopolitan inversion In(3R)Payne in Drosophila melanogaster has been shown to have strong associations with body size in natural populations in eastern Australia (Weeks et al 2002;Rako et al 2006). Furthermore, this relationship is supported by indirect evidence, as QTL mapping indicates, that the region where the inversion is located controls a large amount of variation in body size in Australian and South American populations (Gockel et al 2002;Calboli et al 2003).…”