What does isochore mean?
An isochore is a scientific term used chiefly for a region of DNA in which the proportion of G–C base pairs remains relatively consistent. Such regions can be large, and their composition may differ markedly from that of neighboring DNA. The word also has physical and cartographic uses: an isochore may be a line joining places with equal barometric pressure, equal magnetic intensity, or, on a thermodynamic diagram, equal volume. These senses share the idea of constant or equivalent value across an area or along a line. Isochore is therefore mostly encountered in genetics, geomagnetism, meteorology, and thermodynamics rather than general prose. It is pronounced with stress on the first syllable and is usually pluralized as “isochores.” Though less common than related labels such as “isobar” in some fields, “isochore” remains especially useful in genetics because it names a recognized feature of genome organization. The word rewards readers for noticing that a single term can describe both a physical map line and a broad, statistically uniform stretch of DNA.
nounAn isochore is a region of DNA characterized by relatively uniform GC content. In cartography and physics, the term may also denote a line joining points of equal barometric pressure, magnetic intensity, or volume.
- A region of DNA whose GC content is relatively uniform.
- A line joining points of equal magnetic intensity.
- A line joining points of equal barometric pressure.
- A line on a thermodynamic diagram joining points of equal volume.
"The researchers mapped the genome into long isochores with distinct GC contents."
"The genome can be divided into large isochores with distinctly different GC contents."
"On the old weather chart, an isochore connected stations reporting the same atmospheric pressure."
The standard plural form, used regularly in genetics and the physical sciences.
"Several long isochores were identified in the genome."
The same word that appears on weather maps can also describe the hidden genetic landscapes of DNA.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does isochore come from?
Isochore combines the Greek prefix iso-, meaning “equal,” with an element derived from Greek khōra, meaning “space” or “place.” The term was used in English during the 19th century for equal-value lines on maps and diagrams before its specialized application to DNA composition. It belongs to a larger family of scientific words formed with iso-, including isobar, isotherm, and isochronous.
Related word forms
How isochore is actually used
This is specialized scientific terminology, encountered chiefly in genetics, geomagnetism, meteorology, and thermodynamics. It is uncommon in general prose.
Easily confused with isochore
Both can denote a line joining places of equal atmospheric pressure, but isobar is the conventional meteorological term, whereas isochore also has established uses in genetics and geomagnetism.
Isochronous means occurring in equal amounts of time, while isochore primarily denotes a genetically uniform DNA region or a line joining points of equal value.