Gene duplication is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene. Gene duplications can arise as products of several types of errors in DNA replication and repair machinery as well as through fortuitous capture by selfish genetic elements. Common sources of gene duplications include ectopic recombination, retrotransposition event, aneuploidy, polyploidy, and replication slippage.
Double minutes (DMs) are small fragments of extrachromosomal DNA, which have been observed in a large number of human tumors including breast, lung, ovary, colon, and most notably, neuroblastoma. They are a manifestation of gene amplification as a result of chromothripsis, during the development of tumors, which give the cells selective advantages for growth and survival. This selective advantage is as a result of double minutes frequently harboring amplified oncogenes and genes involved in drug resistance. DMs, like actual chromosomes, are composed of chromatin and replicate in the nucleus of the cell during cell division. Unlike typical chromosomes, they are composed of circular fragments of DNA, up to only a few million base pairs in size, and contain no centromere or telomere. Further to this, they often lack key regulatory elements, allowing genes to be constitutively expressed. The term ecDNA may be used to refer to DMs in a more general manner. The term Double Minute originates from the visualization of these features under microscope; double because the dots were found in pairs, and minute because they were minuscule.
Palaeospondylus is a prehistoric fish, a fossil vertebrate. Its fossils are described from the Achanarras slate quarry in Caithness, Scotland.
Extrachromosomal DNA is any DNA that is found off the chromosomes, either inside or outside the nucleus of a cell. Most DNA in an individual genome is found in chromosomes contained in the nucleus. Multiple forms of extrachromosomal DNA exist, and, while some of these serve important biological functions, they can also play a role in diseases such as cancer.
In molecular biology, SWI/SNF, is a subfamily of ATP-dependent chromatin remodeling complexes, which is found in eukaryotes. In other words, it is a group of proteins that associate to remodel the way DNA is packaged. This complex is composed of several proteins – products of the SWI and SNF genes, as well as other polypeptides. It possesses a DNA-stimulated ATPase activity that can destabilize histone-DNA interactions in reconstituted nucleosomes in an ATP-dependent manner, though the exact nature of this structural change is unknown. The SWI/SNF subfamily provides crucial nucleosome rearrangement, which is seen as ejection and/or sliding. The movement of nucleosomes provides easier access to the chromatin, enabling binding of specific transcription factors, and allowing genes to be activated or repressed.
Sean J. Morrison is a Canadian-American stem cell biologist and cancer researcher. Morrison is the director of Children's Medical Center Research Institute at UT Southwestern (CRI), a nonprofit research institute established in 2011 as a joint venture between Children’s Health System of Texas and UT Southwestern Medical Center. With Morrison as founding director, CRI was established to perform transformative biomedical research at the interface of stem cell biology, cancer and metabolism to better understand the biological basis of disease. He is a Howard Hughes Medical Institute Investigator, has served as president of the International Society for Stem Cell Research, and is a member of the U.S. National Academy of Medicine, U.S. National Academy of Sciences and European Molecular Biology Organization.
Sir Stephen Philip Jackson, FRS, FMedSci is the Frederick James Quick Professor of Biology. He is a senior group leader at the Cancer Research UK Cambridge Institute and associate group leader at the Gurdon Institute, University of Cambridge.
Haplogroup HIJK, defined by the SNPs F929, M578, PF3494 and S6397, is a common Y-chromosome haplogroup. Like its parent macrohaplogroup GHIJK, Haplogroup HIJK and its subclades comprise the vast majority of the world's male population.
Extrachromosomal circular DNA (eccDNA) is a type of double-stranded circular DNA structure that was first discovered in 1964 by Alix Bassel and Yasuo Hotta. In contrast to previously identified circular DNA structures, eccDNA are circular DNA found in the eukaryotic nuclei of plant and animal cells. Extrachromosomal circular DNA is derived from chromosomal DNA, can range in size from 50 base pairs to several mega-base pairs in length, and can encode regulatory elements and full-length genes. eccDNA has been observed in various eukaryotic species and it is proposed to be a byproduct of programmed DNA recombination events, such as V(D)J recombination.
Early European Farmers (EEF) were a group of the Anatolian Neolithic Farmers (ANF) who brought agriculture to Europe and Northwest Africa. The Anatolian Neolithic Farmers were an ancestral component, first identified in farmers from Anatolia (also known as Asia Minor) in the Neolithic, and outside in Europe and Northwest Africa, they also existed in Iranian Plateau, South Caucasus, Mesopotamia and Levant. Although the spread of agriculture from the Middle East to Europe has long been recognised through archaeology, it is only recent advances in archaeogenetics that have confirmed that this spread was strongly correlated with a migration of these farmers, and was not just a cultural exchange.
Christopher G. TateFRS is an English membrane protein biochemist and molecular biologist who works at the Medical Research Council Laboratory of Molecular Biology in Cambridge, UK. Tate is known for his contributions to the understanding of G protein-coupled receptors.
Professor Carlos Caldas is a clinician scientist and Professor of Cancer Medicine at the University of Cambridge. He is the Chair of Cancer Medicine at the University of Cambridge, an Honorary Consultant Medical Oncologist at Addenbrooke's Hospital and Director of the Cambridge Breast Cancer Research Unit. He is a fellow of Robinson College, Cambridge and an Emeritus Senior Investigator at the National Institute for Health Research (NIHR).
Vishva Mitra Dixit is a Kenyan-American physician who is currently Vice President and Senior Fellow of Physiological Chemistry and Research Biology at Genentech.
Edward Francis Fritsch is a scientist in the field of molecular biology and cancer immunology.
Jan Karlseder an Austrian molecular biologist, is the Chief Science Officer and a Senior Vice President at the Salk Institute for Biological Studies. He is also a professor in the Molecular and Cellular Biology Laboratory, the Director of the Paul F. Glenn Center for Biology of Aging Research and the holder of the Donald and Darlene Shiley Chair at the Salk Institute for Biological Studies.
Colibactin is a genotoxic metabolite produced by Escherichia coli and other Enterobacteriaceae believed to cause mutations leading to colorectal cancer and the progression of colorectal cancer. Colibactin is a polyketide peptide that can form interstrand crosslinks in DNA. Colibactin is only produced by bacterial strains containing a polyketide synthase genomic island (pks) or clb biosynthetic gene cluster. About 20% of humans in high-income countries are colonized with E. coli that harbor the pks island.
Borgs are large extrachromosomal linear DNA elements found in methanotrophic archaea that live in oxygen-starved environments such as deep mud. They have been found in organisms isolated from wetland, aquifer, and riverbed environments, as well as a deserted mercury mine, in California and Colorado. They were first described by Basem Al-Shayeb and Jill Banfield in 2022.
Christina Curtis is an American scientist who is a Professor of Medicine, Genetics and Biomedical Data Science and an Endowed Scholar at Stanford University where her research investigates the evolution of tumors. She is director of Artificial Intelligence and Cancer Genomics at Stanford University School of Medicine and is on the board of directors of the American Association for Cancer Research.
Florian Markowetz is the Professor of Computational Oncology at the University of Cambridge. He is a Senior Group Leader at the Cancer Research UK Cambridge Institute and Director and co-founder of Tailor Bio, a genomics company aiming to improve precision medicine for cancers with high levels of chromosomal instability.
Hendrik Dietz is a German physicist known for his contributions in the field of DNA origami. He is a full-professor for biophysics at the Technical University of Munich.
