scholarly journals Persistent one-way walking in a circular arena in Drosophila melanogaster Canton-S strain

2017 ◽  
Author(s):  
Chengfeng Xiao ◽  
Shuang Qiu ◽  
R Meldrum Robertson

AbstractWe describe persistent one-way walking of Drosophila melanogaster in a circular arena. Wild-type Canton-S adult flies walked in one direction, counter-clockwise or clockwise, for minutes, whereas white-eyed mutant w1118 changed directions frequently. Locomotion in the circular arena could be classified into four components: counter-clockwise walking, clockwise walking, nondirectional walking and pausing. Genetic analysis revealed that while wild-type genetic background was associated with reduced directional change and reduced numbers of one-way (including counterclockwise and clockwise) and nondirectional walks, the white (w+) locus promoted persistent oneway walking by increasing the maximal duration of one-way episodes. The promoting effect of w+ was further supported by the observations that (1) w+ duplicated to the Y chromosome, (2) four genomic copies of mini-white inserted on the autosomes, and (3) pan-neuronal overexpression of the White protein increased the maximal duration of one-way episodes, and that RNAi knockdown of w+ in the neurons decreased the maximal duration of one-way episodes. These results suggested a pleiotropic function of w+ in promoting persistent one-way walking in the circular arena.

Genetics ◽  
1972 ◽  
Vol 70 (4) ◽  
pp. 595-610
Author(s):  
Ray Moree

ABSTRACT The viability effects of chromosomes from an old and from a new laboratory strain of D. melanogaster were studied in eight factorial combinations and at two heterozygosity levels. The combinations were so constructed that heterozygosity level could be varied in the third chromosomes of the carriers of a homozygous lethal marker, in the third chromosomes of their wild-type segregants, and in the genetic backgrounds of both. Excluding the effect of the marker and the exceptional outcomes of two of the combinations, and taking into account both large and small deviations from theoretical expectation, the following summary is given as the simplest consistent explanation of the results: 1) If total heterozygosities of two segregant types tend toward equality their viabilities tend toward equality also, whether background heterozygosity is high or low; if background heterozygosities is higher the tendency toward equality is slightly greater. 2) If total heterozygosity of two segregant types are unequal the less heterozygous type has the lower viability; the difference is more pronounced when background heterozygosity is low, less when it is high. 3) Differences between segregant viabilities are correlated with differences between the total heterozygosities of the two segregants; genetic background is effective to the extent, and only to the extent, that it contributes to the magnitude of this difference. This in turn appears to underlie, at least partly, the expression of a pronounced interchromosomal epistasis. Thus in this study viability is seen to depend upon both the quantity and distribution of heterozygosity, not only among the chromosomes of an individual but among the individuals of a given combination as well.


Chromosoma ◽  
1983 ◽  
Vol 88 (5) ◽  
pp. 349-373 ◽  
Author(s):  
Maurizio Gatti ◽  
Sergio Pimpinelli

2020 ◽  
Author(s):  
Yassi Hafezi ◽  
Samantha R. Sruba ◽  
Steven R. Tarrash ◽  
Mariana F. Wolfner ◽  
Andrew G. Clark

ABSTRACTGene-poor, repeat-rich regions of the genome are poorly understood and have been understudied due to technical challenges and the misconception that they are degenerating “junk”. Yet multiple lines of evidence indicate these regions may be an important source of variation that could drive adaptation and species divergence, particularly through regulation of fertility. The ∼40 Mb Y chromosome of Drosophila melanogaster contains only 16 known protein-coding genes and is highly repetitive and entirely heterochromatic. Most of the genes originated from duplication of autosomal genes and have reduced nonsynonymous substitution rates, suggesting functional constraint. We devised a genetic strategy for recovering and retaining stocks with sterile Y-linked mutations and combined it with CRISPR to create mutants with deletions that disrupt three Y-linked genes. Two genes, PRY and FDY, had no previously identified functions. We found that PRY mutant males are sub-fertile, but FDY mutant males had no detectable fertility defects. FDY, the newest known gene on the Y chromosome, may have fertility effects that are conditional or too subtle to detect. The third gene, CCY, had been predicted but never formally shown to be required for male fertility. CRISPR-targeting and RNAi of CCY caused male sterility. Surprisingly, however, our CCY mutants were sterile even in the presence of an extra wild-type Y chromosome, suggesting that perturbation of the Y chromosome can lead to dominant sterility. Our approach provides an important step toward understanding the complex functions of the Y chromosome and parsing which functions are accomplished by genes versus repeat elements.


1979 ◽  
Vol 34 (3-4) ◽  
pp. 304-305 ◽  
Author(s):  
Michael M. Bentley ◽  
John H. Williamson

Abstract A new locus, Aldox-2, which affects the activity and heat stability of aldehyde oxidase in D. melanogaster is described. The Aldox-2 locus is localized to map position 86 on chromosome 2, between c and px. Aldehyde oxidase activity in Aldox-2 homozygotes is approximately 25 - 30% that of the Oregon-R wild-type control strain. The enzyme from the mutant stock is much more heat labile than is the enzyme from the wild-type strain. Both the activity and heat phenotypes are completely recessive.


Genetics ◽  
1977 ◽  
Vol 86 (3) ◽  
pp. 567-582
Author(s):  
L Sandler

ABSTRACT It is proposed that there exists a special region in the euchromatin of the left arm of chromosome 2 (contained within sections 31-32 of the standard salivary gland chromosome map) that is defined by a set of genes, each one of which interacts with a specific sex-chromosome heterochromatic segment. The evidence for the existence of this region is, first, the exhibition, mapping, and analysis of five different maternal-effect, embryonic semi-lethals located in region 31-32. Secondly, in each case the consequence of the maternal effect is markedly influenced by the amount of X- or Y-chromosome heterochromatin carried by the progeny of mutant mothers. The nature of this interaction and possible reasons for the existence of the cluster of autosomal genes are discussed


Genome ◽  
2003 ◽  
Vol 46 (3) ◽  
pp. 343-352 ◽  
Author(s):  
Alistair B Coulthard ◽  
Daniel F Eberl ◽  
Cecil B Sharp ◽  
Arthur J Hilliker

Here we bring together our published and unpublished work with recent published findings of other laboratories to provide a revised map of the centromeric heterochromatin of chromosome 2 and descriptions of the 21 genetic elements therein. These elements consist of 16 vital loci, one male and one female sterile loci, one Minute locus, and two components of the Segregation Distorter system. Based on our latest analysis of the lethal mutant phenotypes of the vital genes, we have provided names for several genes that were previously known by their lethal number assignments.Key words: heterochromatin, Drosophila, cytogenetics.


2016 ◽  
Author(s):  
Chengfeng Xiao ◽  
Shuang Qiu ◽  
R Meldrum Robertson

ABSTRACTCharacteristics of male courtship behavior in Drosophila melanogaster have been well-described, but the genetic basis of male-female copulation is largely unknown. Here we show that the white (w) gene, a classical gene for eye color, is associated with copulation success. 82.5% of wild-type Canton-S flies copulated within 60 minutes in circular arenas, whereas few white-eyed mutants mated successfully. The w+ allele exchanged to the X chromosome or duplicated to the Y chromosome in the white-eyed genetic background rescued the defect of copulation success. The w+-associated copulation success was independent of eye color phenotype. Addition of the mini-white (mw+) gene to the white-eyed mutant rescued the defect of copulation success in a manner that was mw+ copy number-dependent. Lastly, male-female sexual experience mimicked the effects of w+/mw+ in improving successful copulation. These data suggest that the w+ gene controls copulation success in Drosophila melanogaster.


Genetics ◽  
1975 ◽  
Vol 81 (3) ◽  
pp. 515-523
Author(s):  
James D Procunier ◽  
Kenneth D Tartof

ABSTRACT The 5S RNA genes of Drosophila melanogaster in either an isogenic wild-type or a multiply inverted (SM1) chromosome 2 increase their multiplicity when opposite a deficiency for the 5S gene site. This is analogous to the compensation phenomenon previously described for the 18S and 28S ribosomal RNA genes of the X chromosome nucleolus organizer region. Molecular hybridization of 5S RNA to DNA containing various doses of the 56F1-9 region of chromosome 2 demonstrates that most, if not all, of the 5S genes reside in or near this region. Also, a deficiency missing approximately one-half of the wild-type number of 5S genes was isolated and genetically localized. This mutant has a phenotype like that of bobbed, a mutant known to be partially deficient in 18S and 28S ribosomal RNA genes. Finally, we report the existence of a chromosomal rearrangement which splits the second chromosome into two segments, each containing 5S DNA.


Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 30
Author(s):  
Gloria Bartolo ◽  
Leandra O. Gonzalez ◽  
Anastasia Levitin ◽  
Mikhail Martchenko Shilman

The genders of Drosophila melanogaster vary in their sensitivities to microbial pathogens. While many of the immunity-related genes are located on the X chromosome, the polymorphisms within the Y chromosome were also shown to affect the immunity of flies. In this study, we investigated the necessity of individual genes on the Y chromosome (Y-genes) for male sensitivity to microbes. We identified several Y-genes whose genetic inactivation either increases or decreases the sensitivity of males to gastrointestinal infections with fungal Saccharomyces cerevisiae and bacterial Serratia liquefaciens. Specifically, the loss of function mutations in fly kl-5 and Ppr-Y Y-genes lead to increased and decreased sensitivity of males to fungal challenge, respectively, compared to female sensitivity. In contrast, mutations in Drosophila Pp1-Y1, kl-5, kl-3, Ppr-Y, CCY, and FDY Y-genes lead to increased sensitivity of males to bacterial infection, compared to females. Moreover, while these Y-genes are necessary, the Y chromosome is not sufficient for the sensitivity of males to microbes, since the sensitivity of XXY females to fungal and bacterial challenges was not different from the sensitivity of wild-type female flies, compared to males. This study assigns a new immunity-related function to numerous Y-genes in D.melanogaster.


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