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Updated: Aug 13, 2026

Determination of Reproductive Competence by Confirming Pubertal Onset and Performing a Fertility Assay in Mice and Rats
Published on: October 13, 2018
Testatin transgenic and knockout mice exhibit normal sex-differentiation
Kouichi Hasegawa1, Shinichiro Chuma, Takashi Tada
1Department of Development and Differentiation, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara, Shogoin, Sakyo, Kyoto 606-8507, Japan. khase@frontier.kyoto-u.ac.jp
Testatin, a cystatin family member, is expressed in reproductive tissues. Its altered expression in mice did not impact fertility or sex differentiation, suggesting it is dispensable for these processes.
Area of Science:
- Reproductive Biology
- Developmental Biology
- Genetics
Background:
- Testatin, a member of the Cystatin family, is expressed in reproductive tissues.
- Testatin expression patterns differ between male and female gonads post-sex differentiation onset.
- These distinct patterns suggest a potential role for Testatin in mammalian sex determination.
Purpose of the Study:
- To investigate the functional role of Testatin in mammalian sex differentiation.
- To determine if Testatin is essential for normal gonad development and function.
Main Methods:
- Generation of testatin transgenic mice with ectopic expression in females.
- Generation of testatin knockout mice with null expression in males.
- Analysis of fertility and phenotypic abnormalities in genetically modified mice.
Main Results:
- Transgenic females exhibited constitutively elevated Testatin levels, comparable to wild-type males.
- Testatin knockout males showed no Testatin expression.
- Both transgenic and knockout mice were fertile and displayed no detectable abnormalities in sex differentiation or development.
Conclusions:
- The down-regulation of Testatin in female gonads is not critical for normal development.
- The up-regulation of Testatin in male gonads is dispensable for male sex differentiation.
- Testatin does not play an essential role in mammalian sex determination or reproductive function.
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