Epigenetik
Nogle epigenetiske mekanismer
Epigenetik er den del af genetikken som omhandler arvelige men reversible forandringer i genudtryk eller fænotype, som er uafhængig af forandringer i DNA-sekvensen. Prefikset epi- kommer af græsk επί hvilket betyder "ved siden af", og henviser til at forandringerne sker udenfor selve DNA-sekvensen.
I multicellulære organismer udvikles flere forskellige celletyper, som giver ophav til forskellig væv og organer. Denne differentiering til forskellige celletyper sker ved at gener "slukkes" eller "tændes". Når en differentieret celle senere deler sig, bibeholdes genudtrykket i afkomscellerne, såkaldt epigenetisk nedarvning.
Epigenetiske mekanismer påvirkes af faktorer såsom alder, forurening, stress, kemikalier, lægemidler og diæt.[1][2]
Se også
- Epigenom
- Histon - anvendes i prokayoter
- Genregulering
- DNA-methylering
- Cis-reguleringselement
Kilder/referencer
- ^ "14. august 2013, videnskab.dk: Opvækstens omgivelser påvirker hjernens gener. I løbet af barndommen og ungdommen går menneskehjernen igennem en voldsom forandring. Nu ved forskerne mere om, hvordan ændringen sker.". Arkiveret fra originalen 18. august 2013. Hentet 20. august 2013.
- ^ 1 December 2013, BBC News: 'Memories' pass between generations. Behaviour can be affected by events in previous generations which have been passed on through a form of genetic memory, animal studies suggest. Arkiveret 8. december 2013 hos Wayback Machine Citat: "...The findings provide evidence of "transgenerational epigenetic inheritance" - that the environment can affect an individual's genetics, which can in turn be passed on...He commented: "It is high time public health researchers took human transgenerational responses seriously..."
Eksterne henvisninger
- DR P1: Videnskabens Verden: Fede mænds sæd [08. december 2015] [1]
- Vetenskapsradion i P1, har tagit upp epigenetik. P1 om Epigenetik.
- BBC har i en serie kallad The Ghost In Your Genes tagit upp ämnet: BBC dokumentär 2008 Arkiveret 30. marts 2016 hos Wayback Machine.
|
Medier brugt på denne side
Epigenetic mechanisms.png
Epigenetic mechanisms are affected by several factors and processes including development in utero and in childhood, environmental chemicals, drugs and pharmaceuticals, aging, and diet. DNA methylation is what occurs when methyl groups, an epigenetic factor found in some dietary sources, can tag DNA and activate or repress genes. Histones are proteins around which DNA can wind for compaction and gene regulation. Histone modification occurs when the binding of epigenetic factors to histone “tails” alters the extent to which DNA is wrapped around histones and the availability of genes in the DNA to be activated. All of these factors and processes can have an effect on people’s health and influence their health possibly resulting in cancer, autoimmune disease, mental disorders, or diabetes among other illnesses. National Institutes of Health
Epigenetic mechanisms are affected by several factors and processes including development in utero and in childhood, environmental chemicals, drugs and pharmaceuticals, aging, and diet. DNA methylation is what occurs when methyl groups, an epigenetic factor found in some dietary sources, can tag DNA and activate or repress genes. Histones are proteins around which DNA can wind for compaction and gene regulation. Histone modification occurs when the binding of epigenetic factors to histone “tails” alters the extent to which DNA is wrapped around histones and the availability of genes in the DNA to be activated. All of these factors and processes can have an effect on people’s health and influence their health possibly resulting in cancer, autoimmune disease, mental disorders, or diabetes among other illnesses. National Institutes of Health