Drosophila is a genus of flies, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit. They should not be confused with the Tephritidae, a related family, which are also called fruit flies ; tephritids feed primarily on unripe or ripe fruit, with many species being regarded as destructive agricultural pests, especially the Mediterranean fruit fly.
The XY sex-determination system is a sex-determination system used to classify many mammals, including humans, some insects (Drosophila), some snakes, some fish (guppies), and some plants. In this system, the sex of an individual is determined by a pair of sex chromosomes. Females have two of the same kind of sex chromosome (XX), and are called the homogametic sex. Males have two different kinds of sex chromosomes (XY), and are called the heterogametic sex.
A sex-determination system is a biological system that determines the development of sexual characteristics in an organism. Most organisms that create their offspring using sexual reproduction have two common sexes and a few less common intersex variations.
Drosophila melanogaster is a species of fly in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly", or "banana fly". In the wild, D. melanogaster are attracted to rotting fruit and fermenting beverages, and are often found in orchards, kitchens and pubs.
Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. Sex determination is often distinct from sex differentiation; sex determination is the designation for the development stage towards either male or female, while sex differentiation is the pathway towards the development of the phenotype.
Sex-determining region Y protein (SRY), or testis-determining factor (TDF), is a DNA-binding protein encoded by the SRY gene that is responsible for the initiation of male sex determination in therian mammals. SRY is an intronless sex-determining gene on the Y chromosome. Mutations in this gene lead to a range of disorders of sex development with varying effects on an individual's phenotype and genotype.
Dosage compensation is the process by which organisms equalize the expression of genes between members of different biological sexes. Across species, different sexes are often characterized by different types and numbers of sex chromosomes. In order to neutralize the large difference in gene dosage produced by differing numbers of sex chromosomes among the sexes, various evolutionary branches have acquired various methods to equalize gene expression among the sexes. Because sex chromosomes contain different numbers of genes, different species of organisms have developed different mechanisms to cope with this inequality. Replicating the actual gene is impossible; thus organisms instead equalize the expression from each gene. For example, in humans, female (XX) cells randomly silence the transcription of one X chromosome, and transcribe all information from the other, expressed X chromosome. Thus, human females have the same number of expressed X-linked genes per cell as do human males (XY), both sexes having essentially one X chromosome per cell, from which to transcribe and express genes.
X hyperactivation refers to the process in Drosophila by which genes on the X chromosome in male flies become twice as active as genes on the X chromosome in female flies.
The fruitless gene (fru) is a Drosophila melanogaster gene that encodes several variants of a putative transcription factor protein. Normal fruitless function is required for proper development of several anatomical structures necessary for courtship, including motor neurons which innervate muscles needed for fly sexual behaviors. The gene does not have an obvious mammalian homolog, but appears to function in sex determination in species as distant as the mosquito Anopheles gambiae.
white, abbreviated w, was the first sex-linked mutation discovered, found in the fruit fly Drosophila melanogaster. In 1910 Thomas Hunt Morgan and Lilian Vaughan Morgan collected a single male white-eyed mutant from a population of Drosophila melanogaster fruit flies, which usually have dark brick red compound eyes. Upon crossing this male with wild-type female flies, they found that the offspring did not conform to the expectations of Mendelian inheritance. The first generation produced 1,237 red-eyed offspring and three white-eyed male flies. The second generation produced 2,459 red-eyed females, 1,011 red-eyed males, and 782 white-eyed males. Further experimental crosses led them to the conclusion that this mutation was somehow physically connected to the "factor" that determined sex in Drosophila. This led to the discovery of sex linkage, in which the gene for a trait is found on a sex chromosome. Morgan named this trait white, now abbreviated w. Flies possessing the white allele are frequently used to introduce high school and college students to genetics.
A genetically modified (GM) insect is an insect that has been genetically modified, either through mutagenesis, or more precise processes of transgenesis, or cisgenesis. Motivations for using GM insects include biological research purposes and genetic pest management. Genetic pest management capitalizes on recent advances in biotechnology and the growing repertoire of sequenced genomes in order to control pest populations, including insects. Insect genomes can be found in genetic databases such as NCBI, and databases more specific to insects such as FlyBase, VectorBase, and BeetleBase. There is an ongoing initiative started in 2011 to sequence the genomes of 5,000 insects and other arthropods called the i5k. Some Lepidoptera have been genetically modified in nature by the wasp bracovirus.
Doublesex (dsx) is a gene that is involved in the sex determination system of many insects including the fruit fly Drosophila melanogaster.
Female sperm storage is a biological process and often a type of sexual selection in which sperm cells transferred to a female during mating are temporarily retained within a specific part of the reproductive tract before the oocyte, or egg, is fertilized. This process takes place in some species of animals, but not in humans. The site of storage is variable among different animal taxa and ranges from structures that appear to function solely for sperm retention, such as insect spermatheca and bird sperm storage tubules, to more general regions of the reproductive tract enriched with receptors to which sperm associate before fertilization, such as the caudal portion of the cow oviduct containing sperm-associating annexins. Female sperm storage is an integral stage in the reproductive process for many animals with internal fertilization. It has several documented biological functions including:
Interlocus sexual conflict is a type of sexual conflict that occurs through the interaction of a set of antagonistic alleles at two or more different loci, or the location of a gene on a chromosome, in males and females, resulting in the deviation of either or both sexes from the fitness optima for the traits. A co-evolutionary arms race is established between the sexes in which either sex evolves a set of antagonistic adaptations that is detrimental to the fitness of the other sex. The potential for reproductive success in one organism is strengthened while the fitness of the opposite sex is weakened. Interlocus sexual conflict can arise due to aspects of male–female interactions such as mating frequency, fertilization, relative parental effort, female remating behavior, and female reproductive rate.
Female-specific protein transformer is a protein that in Drosophila melanogaster is encoded by the tra gene. Unlike the related tra2 protein, it is only produced in females.
Seminal fluid proteins (SFPs) or accessory gland proteins (Acps) are one of the non-sperm components of semen. In many animals with internal fertilization, males transfer a complex cocktail of proteins in their semen to females during copulation. These seminal fluid proteins often have diverse, potent effects on female post-mating phenotypes. SFPs are produced by the male accessory glands.
The Drosophila quinaria species group is a speciose lineage of mushroom-feeding flies studied for their specialist ecology, their parasites, population genetics, and the evolution of immune systems. Quinaria species are part of the Drosophila subgenus.
Mariana Federica Wolfner is the Goldwin Smith Professor of molecular biology and genetics at Cornell University. Her research investigates sexual conflict in the fruit fly Drosophila melanogaster. She was elected a member of the National Academy of Sciences (NAS) in 2019 in recognition of her distinguished and continuing achievements in original research.
Drosophila metlerri, commonly known as the Sonoran Desert fly, is a fly in the genus Drosophila. The species is found in North America and is most concentrated along the southern coast of California and in Mexico. D. mettleri are dependent on plant hosts, namely, the saguaro and cardon cacti. Thus, they are most prevalent in arid, desert conditions. It is able to detoxify chemicals found in the rotting liquid of cacti hosts, which allows it to use otherwise lethal soil as a nesting site.
Sex-lethal (Sxl) is a gene found in Dipteran insects, named for its mutation phenotype in Drosophila melanogaster. It is most closely related to the ELAV/HUD subfamily of splicing factors.
