Valeria Zonato

University of Leicester | LE · Department of Genetics

couch potato (cpo) encodes an RNA binding protein that has been reported to be expressed in the peripheral and central nervous system of embryos, larvae and adults, including the major endocrine organ, the ring gland. A polymorphism in the D. melanogaster cpo gene coding region displays a latitudinal cline in frequency in North American populations...

D. melanogaster enters a state of reproductive arrest when exposed to low temperatures (12°C) and shorter photoperiods. A number of studies have suggested that diapause has recently evolved in European D. melanogaster populations, that it is not present in the sibling species D. simulans, that it is non-photoperiodic in American D. melanogaster pop...

Seasonal overwintering in insects represents an adaptation to stressful environments and in European Drosophila melanogaster females, low temperatures and short photoperiods can induce an ovarian diapause. Diapause may represent a recent (<15Ky) adaptation to the colonisation of temperate Europe by D. melanogaster from tropical sub-Saharan Africa,...

The spread of adaptive genetic variants in populations is a cornerstone of evolutionary theory but with relatively few biologically well-understood examples. Previous work on the ls-tim variant of timeless, which encodes the light-sensitive circadian regulator in Drosophila melanogaster, suggests that it may have originated in southeastern Italy. F...

Like many other insects in temperate regions, Drosophila melanogaster exploits the photoperiod shortening that occurs during the autumn as an important cue to trigger a seasonal response. Flies survive the winter by entering a state of reproductive arrest (diapause), which drives the relocation of resources from reproduction to survival. Here, we p...

cpo48034(A/T) genotype frequencies against latitude. Panels A, B and C show how the SNP cpo48034(A/T) genotype frequencies (A/A, A/T and T/T respectively), change with latitude of collection. (JPG)

Details of the flies used in the SNP cpo48034(A/T) study. N: number of alleles analysed. Lat: latitude in degrees North. Long: longitude in degrees (Negative values: West; Positive values: East). Alt: altitude in metres above sea level. The last column shows the results of the Hardy-Weinberg test. *: p<0.05. (DOCX)

LD values calculated for each individual population and for the whole dataset. The analysis was carried out including the heterozygotes for both SNPs (DH, Double Heterozygotes), and excluding them from the dataset. When DH are included, observed frequency of each haplotype was estimated by the software, based on Maximum Likelihood The last row show...

Details of the flies used in the cpoAla347Val study. N: number of alleles analysed. Lat: latitude in degrees North. Long: longitude in degrees (Negative values: West; Positive values: East). Alt: altitude in meters above sea level. The last column shows the results of the Hardy-Weinberg test. *: p<0.01; ***: p<0.001. (DOCX)

cpo isoforms as of September 2008. Schematic representation of the six cpo splicing variants. Dark blue boxes encode the protein, whereas light blue ones represent the 5? and 3? UTR regions. The red and blue arrows represent the position of (then) SNP ?A356V? and SNP ?48034 (A/T)? respectively. The figure is not to scale and was redrawn from the da...

Frequency of In(3R)Payne in a subset of the European populations. N: number of alleles analysed. f(st) frequency of standard arrangements. f(in) frequency of inverted chromosomes. CL: 95% confidence limits calculated with the Wilson/Brown method. (DOCX)

Results of 4-way ANOVAs on diapause. LD: experimental samples. DD: controls. Significant values are indicated in red. (DOCX)

cpoA347V genotype frequencies against latitude. Panels A, B and C show how cpoAla347Val genotype frequencies (C/C, T/C, T/T respectively), change with latitude of collection. *: p<0.05. (JPG)

Diapause incidence in the Treviso population (TOT) and in the four sublines (sTA, sTT, sCA and sCT) under constant darkness (DD). Y axis: percentage of diapause in two replicates per population (1 and 2). A) Diapause in LD 8:16. The two time points are compared (12 and 28 days, dotted and plain bars respectively). B) Diapause in 16:8, comparison be...