THE LOCATION OF A NEW SECOND CHROMOSOME EYE COLOUR GENE IN DROSOPHILA MELANOGASTER

From six captures of Drosophila melanogaster carried out in three different habitats (cellar, vineyard, and pinewood) in two different seasons of the year (spring and autumn), 60 eye-colour mutations were isolated, which were reduced to 29 loci by means of allelism tests within and between populations. Forty-five of these mutations were analyzed genetically and biochemically; of these 33 turned out to be previously described mutants and mapped to a total of 17 loci. Twelve new mutants were discovered and they mapped to 12 new loci, distributed on chromosomes X, II, and III. The eye-colour mutants show large effects on the red and brown pigments. The high variability of the eye-colour loci is discussed in relation to the mutation and selection hypotheses.Key words: eye-colour mutants, variability, mapping, Drosophila melanogaster, pigment patterns.

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Transgenerational effect of drug-mediated inhibition of LSD1 on eye pigment expression in Drosophila

BMC Ecology ◽

10.1186/s12898-020-00330-6 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Sigrid Hoyer-Fender

Keyword(s):

Gene Expression ◽

Drosophila Melanogaster ◽

Histone Modifications ◽

Optical Measurement ◽

Position Effect ◽

Position Effect Variegation ◽

Drug Induced ◽

Lysine Specific Demethylase ◽

Eye Colour

Abstract Background The Drosophila melanogaster mutant white-mottled is a well-established model for position-effect variegation (PEV). Transposition of the euchromatic white gene into the vicinity of the pericentric heterochromatin caused variegated expression of white due to heterochromatin spreading. The establishment of the euchromatin-heterochromatin boundary and spreading of silencing is regulated by mutually exclusive histone modifications, i.e. the methylations of histone H3 at lysine 9 and lysine 4. Demethylation of H3K4, catalysed by lysine-specific demethylase LSD1, is required for subsequent methylation of H3K9 to establish heterochromatin. LSD1 is therefore essential for heterochromatin formation and spreading. We asked whether drug-mediated inhibition of LSD affects the expression of white and if this induced change can be transmitted to those generations that have never been exposed to the triggering signal, i.e. transgenerational epigenetic inheritance. Results We used the lysine-specific demethylase 1 (LSD1)-inhibitor Tranylcypromine to investigate its effect on eye colour expression in consecutive generations by feeding the parental and F1 generations of the Drosophila melanogaster mutant white-mottled. Quantitative Western blotting revealed that Tranylcypromine inhibits H3K4-demethylation both in vitro in S2 cells as well as in embryos when used as feeding additive. Eye colour expression in male flies was determined by optical measurement of pigment extracts and qRT-PCR of white gene expression. Flies raised in the presence of Tranylcypromine and its solvent DMSO showed increased eye pigment expression. Beyond that, eye pigment expression was also affected in consecutive generations including F3, which is the first generation without contact with the inhibitor. Conclusions Our results show that feeding of Tranylcypromine and DMSO caused desilencing of white in treated flies of generation F1. Consecutive generations, raised on standard food without further supplements, are also affected by the drug-induced alteration of histone modifications. Although eye pigment expression eventually returned to the basal state, the observed long-lasting effect points to a memory capacity of previous epigenomes. Furthermore, our results indicate that food compounds potentially affect chromatin modification and hence gene expression and that the alteration is putatively inherited not only parentally but transgenerationally.

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Effect of alcohol and competition levels on viability of eye colour mutants of Drosophila melanogaster

Genetics Selection Evolution ◽

10.1186/1297-9686-17-3-331 ◽

1985 ◽

Vol 17 (3) ◽

pp. 331 ◽

Cited By ~ 2

Author(s):

Carmen Nájera ◽

JL Ménsua

Keyword(s):

Drosophila Melanogaster ◽

Eye Colour

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Thelightgene ofDrosophila melanogasterencodes a homologue ofVPS41, a yeast gene involved in cellular-protein trafficking

Genome ◽

10.1139/g98-017 ◽

1998 ◽

Vol 41 (2) ◽

pp. 236-243 ◽

Cited By ~ 34

Author(s):

T S Warner ◽

DAR Sinclair ◽

K A Fitzpatrick ◽

M Singh ◽

R H Devlin ◽

...

Keyword(s):

Gene Product ◽

Protein Trafficking ◽

Cellular Protein ◽

Transport Processes ◽

Cellular Transport ◽

Yeast Gene ◽

Colour Gene ◽

Eye Colour ◽

A Subunit ◽

Cloned Cdna

Mutations in a number of genes affect eye colour in Drosophila melanogaster; some of these "eye-colour" genes have been shown to be involved in various aspects of cellular transport processes. In addition, combinations of viable mutant alleles of some of these genes, such as carnation (car) combined with eitherlight (lt) or deep-orange (dor) mutants, show lethal interactions. Recently, dor was shown to be homologous to the yeast gene PEP3 (VPS18), which is known to be involved in intracellular trafficking. We have undertaken to extend our earlier work on the lt gene, in order to examine in more detail its expression pattern and to characterize its gene product via sequencing of a cloned cDNA. The gene appears to be expressed at relatively high levels in all stages and tissues examined, and shows strong homology to VPS41, a gene involved in cellular-protein trafficking in yeast and higher eukaryotes. Further genetic experiments also point to a role for lt in transport processes: we describe lethal interactions between viable alleles of lt and dor, as well as phenotypic interactions (reductions in eye pigment) between alleles of lt and another eye-colour gene, garnet (g),whose gene product has close homology to a subunit of the human adaptor complex, AP-3.Key words: vesicle transport, eye-colour gene, heterochromatin.

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