Non-coding DNA (ncDNA) sequences are components of an organism's DNA that do not encode protein sequences. Some non-coding DNA is transcribed into functional non-coding RNA molecules. Other functional regions of the non-coding DNA fraction include regulatory sequences that control gene expression; scaffold attachment regions; origins of DNA replication; centromeres; and telomeres. Some non-coding regions appear to be mostly nonfunctional such as introns, pseudogenes, intergenic DNA, and fragments of transposons and viruses.
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.
A chromosomal fragile site is a specific heritable point on a chromosome that tends to form a gap or constriction and may tend to break when the cell is exposed to partial replication stress. Based on their frequency, fragile sites are classified as "common" or "rare". To date, more than 120 fragile sites have been identified in the human genome.
The miR-10 microRNA precursor is a short non-coding RNA gene involved in gene regulation. It is part of an RNA gene family which contains miR-10, miR-51, miR-57, miR-99 and miR-100. miR-10, miR-99 and miR-100 have now been predicted or experimentally confirmed in a wide range of species. mir-51 and mir-57 have currently only been identified in the nematode Caenorhabditis elegans.
The miR-15 microRNA precursor family is made up of small non-coding RNA genes that regulate gene expression. The family includes the related mir-15a and mir-15b sequences, as well as miR-16-1, miR-16-2, miR-195 and miR-497. These six highly conserved miRNAs are clustered on three separate chromosomes. In humans miR-15a and miR-16 are clustered within 0.5 kilobases at chromosome position 13q14. This region has been found to be the most commonly affected in chronic lymphocytic leukaemia (CLL), with deletions of the entire region in more than half of cases. Both miR-15a and miR-16 are thus frequently deleted or down-regulated in CLL samples with 13q14 deletions; occurring in more than two thirds of CLL cases. The expression of miR-15a is associated with survival in triple negative breast cancer.
The miR-16 microRNA precursor family is a group of related small non-coding RNA genes that regulates gene expression. miR-16, miR-15, mir-195 and miR-497 are related microRNA precursor sequences from the mir-15 gene family. This microRNA family appears to be vertebrate specific and its members have been predicted or experimentally validated in a wide range of vertebrate species.
In molecular biology miR-181 microRNA precursor is a small non-coding RNA molecule. MicroRNAs (miRNAs) are transcribed as ~70 nucleotide precursors and subsequently processed by the RNase-III type enzyme Dicer to give a ~22 nucleotide mature product. In this case the mature sequence comes from the 5' arm of the precursor. They target and modulate protein expression by inhibiting translation and / or inducing degradation of target messenger RNAs. This new class of genes has recently been shown to play a central role in malignant transformation. miRNA are downregulated in many tumors and thus appear to function as tumor suppressor genes. The mature products miR-181a, miR-181b, miR-181c or miR-181d are thought to have regulatory roles at posttranscriptional level, through complementarity to target mRNAs. miR-181 which has been predicted or experimentally confirmed in a wide number of vertebrate species as rat, zebrafish, and in the pufferfish.
The miR-29 microRNA precursor, or pre-miRNA, is a small RNA molecule in the shape of a stem-loop or hairpin. Each arm of the hairpin can be processed into one member of a closely related family of short non-coding RNAs that are involved in regulating gene expression. The processed, or "mature" products of the precursor molecule are known as microRNA (miRNA), and have been predicted or confirmed in a wide range of species.
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.
RCC1 and BTB domain-containing protein 1 is a protein that in humans is encoded by the RCBTB1 gene.
Long non-coding RNAs are a type of RNA, generally defined as transcripts more than 200 nucleotides that are not translated into protein. This arbitrary limit distinguishes long ncRNAs from small non-coding RNAs, such as microRNAs (miRNAs), small interfering RNAs (siRNAs), Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), and other short RNAs. Long intervening/intergenic noncoding RNAs (lincRNAs) are sequences of lncRNA which do not overlap protein-coding genes.
In molecular biology, mir-221 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.
A conserved non-coding sequence (CNS) is a DNA sequence of noncoding DNA that is evolutionarily conserved. These sequences are of interest for their potential to regulate gene production.
TUC338 is an ultra-conserved element which is transcribed to give a non-coding RNA. The TUC338 gene was first identified as uc.338, along with 480 other ultra-conserved elements in the human genome. Expression of this RNA gene has been found to dramatically increase in hepatocellular carcinoma (HCC) cells.
An ultra-conserved element (UCE) was originally defined as a genome segment longer than 200 base pairs (bp) that is absolutely conserved, with no insertions or deletions and 100% identity, between orthologous regions of the human, rat, and mouse genomes. 481 ultra-conserved elements have been identified in the human genome. If ribosomal DNA are excluded, these range in size from 200 bp to 781 bp. UCRs are found on all chromosomes except for 21 and Y. A database collecting genomic information about ultra-conserved elements (UCbase) is available at http://ucbase.unimore.it.
miR-138 is a family of microRNA precursors found in animals, including humans. MicroRNAs are typically transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. The excised region or, mature product, of the miR-138 precursor is the microRNA mir-138.
miR-191 is a family of microRNA precursors found in mammals, including humans. The ~22 nucleotide mature miRNA sequence is excised from the precursor hairpin by the enzyme Dicer. This sequence then associates with RISC which effects RNA interference.
MicroRNA sequencing (miRNA-seq), a type of RNA-Seq, is the use of next-generation sequencing or massively parallel high-throughput DNA sequencing to sequence microRNAs, also called miRNAs. miRNA-seq differs from other forms of RNA-seq in that input material is often enriched for small RNAs. miRNA-seq allows researchers to examine tissue-specific expression patterns, disease associations, and isoforms of miRNAs, and to discover previously uncharacterized miRNAs. Evidence that dysregulated miRNAs play a role in diseases such as cancer has positioned miRNA-seq to potentially become an important tool in the future for diagnostics and prognostics as costs continue to decrease. Like other miRNA profiling technologies, miRNA-Seq has both advantages and disadvantages.
In molecular biology mir-32 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.
In molecular biology mir-23 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.
