In molecular biology, Sphinx (spx) is a long non-coding RNA found in Drosophila . It is expressed in the brain, within the antennal lobe and inner antennocerebral tract. [1] It is involved in the regulation of male courtship behaviour, this may be via olfactory neuron mediated regulation. Sphinx may act as a negative regulator of target genes. [1] [2] It is a chimeric gene, originating from a retroposed sequence of the ATP synthase chain F gene from chromosome 2 to chromosome 4. Nearby sequences were recruited to form an intron and an exon of this chimeric gene. [3]
Drosophila is a genus of fly, 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.
An intron is any nucleotide sequence within a gene that is not expressed or operative in the final RNA product. The word intron is derived from the term intragenic region, i.e., a region inside a gene. The term intron refers to both the DNA sequence within a gene and the corresponding RNA sequence in RNA transcripts. The non-intron sequences that become joined by this RNA processing to form the mature RNA are called exons.
Heterochromatin is a tightly packed form of DNA or condensed DNA, which comes in multiple varieties. These varieties lie on a continuum between the two extremes of constitutive heterochromatin and facultative heterochromatin. Both play a role in the expression of genes. Because it is tightly packed, it was thought to be inaccessible to polymerases and therefore not transcribed; however, according to Volpe et al. (2002), and many other papers since, much of this DNA is in fact transcribed, but it is continuously turned over via RNA-induced transcriptional silencing (RITS). Recent studies with electron microscopy and OsO4 staining reveal that the dense packing is not due to the chromatin.
A bacterial artificial chromosome (BAC) is a DNA construct, based on a functional fertility plasmid, used for transforming and cloning in bacteria, usually E. coli. F-plasmids play a crucial role because they contain partition genes that promote the even distribution of plasmids after bacterial cell division. The bacterial artificial chromosome's usual insert size is 150–350 kbp. A similar cloning vector called a PAC has also been produced from the DNA of P1 bacteriophage.
A non-coding RNA (ncRNA) is a functional RNA molecule that is not translated into a protein. The DNA sequence from which a functional non-coding RNA is transcribed is often called an RNA gene. Abundant and functionally important types of non-coding RNAs include transfer RNAs (tRNAs) and ribosomal RNAs (rRNAs), as well as small RNAs such as microRNAs, siRNAs, piRNAs, snoRNAs, snRNAs, exRNAs, scaRNAs and the long ncRNAs such as Xist and HOTAIR.
The origin of replication is a particular sequence in a genome at which replication is initiated. Propagation of the genetic material between generations requires timely and accurate duplication of DNA by semiconservative replication prior to cell division to ensure each daughter cell receives the full complement of chromosomes. This can either involve the replication of DNA in living organisms such as prokaryotes and eukaryotes, or that of DNA or RNA in viruses, such as double-stranded RNA viruses. Synthesis of daughter strands starts at discrete sites, termed replication origins, and proceeds in a bidirectional manner until all genomic DNA is replicated. Despite the fundamental nature of these events, organisms have evolved surprisingly divergent strategies that control replication onset. Although the specific replication origin organization structure and recognition varies from species to species, some common characteristics are shared.
Meiotic drive is a type of intragenomic conflict, whereby one or more loci within a genome will affect a manipulation of the meiotic process in such a way as to favor the transmission of one or more alleles over another, regardless of its phenotypic expression. More simply, meiotic drive is when one copy of a gene is passed on to offspring more than the expected 50% of the time. According to Buckler et al., "Meiotic drive is the subversion of meiosis so that particular genes are preferentially transmitted to the progeny. Meiotic drive generally causes the preferential segregation of small regions of the genome".
Myc is a family of regulator genes and proto-oncogenes that code for transcription factors. The Myc family consists of three related human genes: c-myc (MYC), l-myc (MYCL), and n-myc (MYCN). c-myc was the first gene to be discovered in this family, due to homology with the viral gene v-myc.
This family represents the microRNA (miRNA) precursor mir-7. This miRNA has been predicted or experimentally confirmed in a wide range of species. miRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. In this case the mature sequence comes from the 5' arm of the precursor. The extents of the hairpin precursors are not generally known and are estimated based on hairpin prediction. The involvement of Dicer in miRNA processing suggests a relationship with the phenomenon of RNA interference.
E3 ubiquitin-protein ligase SIAH1 is an enzyme that in humans is encoded by the SIAH1 gene.
Deleted in azoospermia-like is a protein that in humans is encoded by the DAZL gene.
Gerald Mayer Rubin is an American biologist, notable for pioneering the use of transposable P elements in genetics, and for leading the public project to sequence the Drosophila melanogaster genome. Related to his genomics work, Rubin's lab is notable for development of genetic and genomics tools and studies of signal transduction and gene regulation. Rubin also served as a vice president of the Howard Hughes Medical Institute (2003-2020) and founding executive director of its Janelia Research Campus.
AF4/FMR2 family member 1 is a protein that in humans is encoded by the AFF1 gene. At its same location was a record for a separate PBM1 gene, which has since been withdrawn and considered an alias. It was previously known as AF4.
Suppressor of SWI4 1 homolog is a protein that in humans is encoded by the PPAN gene.
MKL/megakaryoblastic leukemia 1 is a protein that in humans is encoded by the MKL1 gene.
Cleavage stimulation factor 77 kDa subunit is a protein that in humans is encoded by the CSTF3 gene.
Protein ENL is a protein that in humans is encoded by the MLLT1 gene.
Chimeric RNA, sometimes referred to as a fusion transcript, is composed of exons from two or more different genes that have the potential to encode novel proteins. These mRNAs are different from those produced by conventional splicing as they are produced by two or more gene loci.
Drosophila circadian rhythm is a daily 24-hour cycle of rest and activity in the fruit flies of the genus Drosophila. The biological process was discovered and is best understood in the species Drosophila melanogaster. Many behaviors are under circadian control including eclosion, locomotor activity, feeding, and mating. Locomotor activity is maximum at dawn and dusk, while eclosion is at dawn.
De novo gene birth is the process by which new genes evolve from non-coding DNA. De novo genes represent a subset of novel genes, and may be protein-coding or instead act as RNA genes. The processes that govern de novo gene birth are not well understood, although several models exist that describe possible mechanisms by which de novo gene birth may occur.