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.
Antisense RNA (asRNA), also referred to as antisense transcript, natural antisense transcript (NAT) or antisense oligonucleotide, is a single stranded RNA that is complementary to a protein coding messenger RNA (mRNA) with which it hybridizes, and thereby blocks its translation into protein. The asRNAs have been found in both prokaryotes and eukaryotes, and can be classified into short and long non-coding RNAs (ncRNAs). The primary function of asRNA is regulating gene expression. asRNAs may also be produced synthetically and have found wide spread use as research tools for gene knockdown. They may also have therapeutic applications.
Polycomb-group proteins are a family of protein complexes first discovered in fruit flies that can remodel chromatin such that epigenetic silencing of genes takes place. Polycomb-group proteins are well known for silencing Hox genes through modulation of chromatin structure during embryonic development in fruit flies. They derive their name from the fact that the first sign of a decrease in PcG function is often a homeotic transformation of posterior legs towards anterior legs, which have a characteristic comb-like set of bristles.
In genomics, a genome-wide association study, is an observational study of a genome-wide set of genetic variants in different individuals to see if any variant is associated with a trait. GWA studies typically focus on associations between single-nucleotide polymorphisms (SNPs) and traits like major human diseases, but can equally be applied to any other genetic variants and any other organisms.
Chromosome conformation capture techniques are a set of molecular biology methods used to analyze the spatial organization of chromatin in a cell. These methods quantify the number of interactions between genomic loci that are nearby in 3-D space, but may be separated by many nucleotides in the linear genome. Such interactions may result from biological functions, such as promoter-enhancer interactions, or from random polymer looping, where undirected physical motion of chromatin causes loci to collide. Interaction frequencies may be analyzed directly, or they may be converted to distances and used to reconstruct 3-D structures.
TNFAIP3-interacting protein 1, also known as ABIN-1, is a protein that in humans is encoded by the TNIP1 gene.
Xist is a non-coding RNA transcribed from the X chromosome of the placental mammals that acts as a major effector of the X-inactivation process. It is a component of the Xic – X-chromosome inactivation centre – along with two other RNA genes and two protein genes.
Ribosome biogenesis protein WDR12 is a protein that in humans is encoded by the WDR12 gene on chromosome 2. It is ubiquitously expressed in many tissues and cell types. WDR12 participates in ribosome biogenesis and cell proliferation as a component of the PeBoW complex. This protein is associated with cardiovascular diseases such as coronary artery disease and myocardial infarction. The PCSK9 gene also contains one of 27 loci associated with increased risk of coronary artery disease.
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. Given that some lncRNAs have been reported to have the potential to encode small proteins or micro-peptides, the latest definition of lncRNA is a class of RNA molecules of over 200 nucleotides that have no or limited coding capacity. Long intervening/intergenic noncoding RNAs (lincRNAs) are sequences of lncRNA which do not overlap protein-coding genes.
TOX high mobility group box family member 3, also known as TOX3, is a human gene.
C-type lectin domain family 16, also known as CLEC16A, is a protein that in humans is encoded by the CLEC16A gene.
Expression quantitative trait loci (eQTLs) are genomic loci that explain variation in expression levels of mRNAs.
The Center for Applied Genomics is a research center at the Children's Hospital of Philadelphia that focuses on genomics research and the utilization of basic research findings in the development of new medical treatments.
An ultraconserved element (UCE) is a region of the genome that is shared between evolutionarily distant taxa and shows little or no variation between those taxa. These regions and regions adjacent to them are useful for tracing the evolutionary history of groups of organisms. Another term for ultraconserved element is ultraconserved region (UCR).
Monocarboxylate transporter 9 is a protein that in humans is encoded by the SLC16A9 gene.
HORMA domain containing 2 is a protein that in humans is encoded by the HORMAD2 gene.
Phosphatase and actin regulator 1 (PHACTR1) is a protein that in humans is encoded by the PHACTR1 gene on chromosome 6. It is most significantly expressed in the globus pallidus of the brain. PHACTR1 is an actin and protein phosphatase 1 (PP1) binding protein that binds actin and regulates the reorganization of the actin cytoskeleton. This protein has been associated with coronary artery disease and migraines through genome-wide association studies. The PHACTR1 gene also contains one of 27 SNPs associated with increased risk of coronary artery disease.
Tuberculosis is a disease caused by the bacterium Mycobacterium tuberculosis. The nature of the host-pathogen interaction between humans and M. tuberculosis is considered to have a genetic component. A group of rare disorders called Mendelian Susceptibility to Mycobacterial Diseases (MSMD) was observed in a subset of individuals with a genetic defect that results in increased susceptibility to Mycobacterial infection.
HHIP-like protein 1 (HHIPL1), also known as HHIP2, is a protein that in humans is encoded by the HHIPL1 gene on chromosome 14. It is not significantly expressed in many tissues and cell types, though HHIPL1 mRNA has been detected in trabecular bone cells. Little is known about the precise biological function of HHIPL1, but the protein has been linked to adenomas. The HHIPL1 gene also contains one of 27 SNPs associated with increased risk of coronary artery disease.
N-Acetylated Alpha-Linked Acidic Dipeptidase Like 2 (NAALADL2) is a protein, encoded by the gene NAALADL2 in humans. NAALADL2 shares 25%–26% sequence identity and 45% sequence similarity with the glutamate carboxypeptidase II family which includes prostate cancer marker PSMA (FOLH1/NAALAD1). The NAALADL2 gene is a giant gene spanning 1.37 Mb which is approximately 49 times larger than the average gene size of 28 kb. Gene length is correlated with the number of transcript variants of a gene, as such, NAALADL2 undergoes extensive alternative splicing and has 12 splice variants as defined by Ensembl.
