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Updated: May 30, 2026
Generation of Maternal Mutants Using zpc:cas9 Knock-in Zebrafish
Published on: July 22, 2025
Mir-290-295 deficiency in mice results in partially penetrant embryonic lethality and germ cell defects
Lea A Medeiros1, Lucas M Dennis, Mark E Gill
1Whitehead Institute for Biomedical Research, Cambridge, MA 02139, USA.
Abstract:
Mir-290 through mir-295 (mir-290-295) is a mammalian-specific microRNA (miRNA) cluster that, in mice, is expressed specifically in early embryos and embryonic germ cells. Here, we show that mir-290-295 plays important roles in embryonic development as indicated by the partially penetrant lethality of mutant embryos. In addition, we show that in surviving mir-290-295-deficient embryos, female but not male fertility is compromised. This impairment in fertility arises from a defect in migrating primordial germ cells and occurs equally in male and female mutant animals. Male mir-290-295(-/-) mice, due to the extended proliferative lifespan of their germ cells, are able to recover from this initial germ cell loss and are fertile. Female mir-290-295(-/-) mice are unable to recover and are sterile, due to premature ovarian failure.
Insights
The mir-290-295 microRNA cluster is crucial for early embryonic development and germ cell survival. While male mice recover fertility, female mice lacking this cluster experience premature ovarian failure and sterility.
Area of Science:
- Developmental Biology
- Genetics
- Reproductive Biology
Background:
- The mir-290-295 microRNA cluster is specific to mammals and expressed during early embryonic stages and in germ cells.
- MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and play vital roles in biological processes.
Purpose of the Study:
- To investigate the function of the mir-290-295 cluster in mouse embryonic development and germ cell development.
- To determine the impact of mir-290-295 deficiency on fertility in male and female mice.
Main Methods:
- Generation of mir-290-295 knockout mouse models.
- Analysis of embryonic lethality and developmental defects in mutant embryos.
- Assessment of primordial germ cell migration and survival.
- Evaluation of fertility and ovarian function in adult mutant mice.
Main Results:
- Mir-290-295 deficiency results in partially penetrant embryonic lethality.
- Mutant embryos exhibit defects in primordial germ cell migration, affecting both sexes.
- Male mice with mir-290-295 deficiency recover germ cell loss and are fertile due to extended germ cell proliferation.
- Female mice with mir-290-295 deficiency are sterile due to premature ovarian failure and inability to recover germ cell loss.
Conclusions:
- The mir-290-295 cluster is essential for normal embryonic development and germ cell maintenance.
- Differential recovery of germ cells between sexes leads to sex-specific infertility phenotypes.
- Mir-290-295 plays a critical role in preventing premature ovarian failure in females.
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