germ line
noun
variants
or germline
: the cellular lineage of a sexually-reproducing organism from which eggs and sperm are derived
also
: the genetic material contained in this cellular lineage which can be passed to the next generation
Examples of germ line in a Sentence
Recent Examples on the Web
In a study involving nearly 1.4 million people who were diagnosed with cancer from 2013 to 2019, only 6.8 percent underwent germ line testing, researchers wrote in JAMA.
—
The Washington Post, San Diego Union-Tribune, 25 Feb. 2025
Both techniques irrevocably alter the germ line, meaning that any changes are passed down to future generations.
—Elizabeth Katkin, Discover Magazine, 17 Jan. 2020
For scientists interested in tinkering with the human germ line, there are three places to introduce edits—in a woman’s egg cells, in a man’s sperm cells, or in the earliest stages of an embryo, when all the genes are housed in stem cells, and tissues have not yet begun to specialize.
—Stephen S. Hall, Wired, 11 Mar. 2021
The only way to avoid this recurrent injection of deleterious alleles into the germ line and mutational abnormality is to engage in some proactive intervention during meiosis, or sift through the gametes prior to in vitro fertilization.
—Razib Khan, Discover Magazine, 12 Sep. 2013
The germ line, produced by egg and sperm, is the only part of us that naturally survives us in our offspring.
—George Church, Discover Magazine, 16 Oct. 2012
This suggested that the butterflies' germ line---the cells that turn into egg and sperm---had suffered damage, so mutations could be expected to continue to accumulate down through the generations.
—Veronique Greenwood, Discover Magazine, 15 Aug. 2012
An international summit on genome editing in 2015 resulted in a report laying out some of the conditions under which editing the human germ line for clinical purposes might one day be allowable.
—Tanya Lewis, Scientific American, 15 Aug. 2019
The survivors made it into the germ line, so the within-lifetime innovations were passed on to subsequent flowers and pollen.
—Elizabeth Pennisi, Science | AAAS, 29 Aug. 2019
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The Washington Post, San Diego Union-Tribune, 25 Feb. 2025
Both techniques irrevocably alter the germ line, meaning that any changes are passed down to future generations.
—Elizabeth Katkin, Discover Magazine, 17 Jan. 2020
For scientists interested in tinkering with the human germ line, there are three places to introduce edits—in a woman’s egg cells, in a man’s sperm cells, or in the earliest stages of an embryo, when all the genes are housed in stem cells, and tissues have not yet begun to specialize.
—Stephen S. Hall, Wired, 11 Mar. 2021
The only way to avoid this recurrent injection of deleterious alleles into the germ line and mutational abnormality is to engage in some proactive intervention during meiosis, or sift through the gametes prior to in vitro fertilization.
—Razib Khan, Discover Magazine, 12 Sep. 2013
The germ line, produced by egg and sperm, is the only part of us that naturally survives us in our offspring.
—George Church, Discover Magazine, 16 Oct. 2012
This suggested that the butterflies' germ line---the cells that turn into egg and sperm---had suffered damage, so mutations could be expected to continue to accumulate down through the generations.
—Veronique Greenwood, Discover Magazine, 15 Aug. 2012
An international summit on genome editing in 2015 resulted in a report laying out some of the conditions under which editing the human germ line for clinical purposes might one day be allowable.
—Tanya Lewis, Scientific American, 15 Aug. 2019
The survivors made it into the germ line, so the within-lifetime innovations were passed on to subsequent flowers and pollen.
—Elizabeth Pennisi, Science | AAAS, 29 Aug. 2019
Cite this Entry
“Germ line.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/germ%20line. Accessed 29 Jul. 2025.
Copy CitationMedical Definition
germ line
noun
variants
or germline
: the cellular lineage especially of a sexually reproducing organism from which eggs and sperm are derived and in which a cell undergoing mutation can be passed to the next generation
… the difference between gene therapy of somatic cells and modification of the germ line …—David Baltimore
David Baltimore
also
: the genetic material contained in this cellular lineage which can be passed to the next generation
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