Summary of ssbd-repos-000348

Name
URL
DOI

Title
Rac1/Rac3-double knockout cochlear hair cells
Description

FRET imaging

Submited Date
2024-05-15
Release Date
2024-07-01
Updated Date
-
License
Funding information
This work was supported by grants from the JSPS KAKENHI (JP19K22472 and JP21H02672 to TU), JSPS KAKENHI on Innovative Areas “Fluorescence Live Imaging” (to NS), the Hyogo Science and Technology Association (30075 to TU), the Naito Foundation (to TU), the Japan Foundation for Applied Enzymology (to TU), the Terumo Life Science Foundation (to TU), the Takeda Science Foundation (to TU), and the Joint Research Program of the Biosignal Research Center, Kobe University (301004 to HS and 192003 to YN).
File formats
mp4
Data size
51.4 MB

Organism
mouse cochlea
Strain
-
Cell Line
-
Genes
-
Proteins
-

GO Molecular Function (MF)
-
GO Biological Process (BP)
-
GO Cellular Component (CC)
-
Study Type
-
Imaging Methods
-

Method Summary

See details in Nakamura, et. al. (2023) J Mol Med (Berl).

Related paper(s)

Takashi Nakamura, Hirofumi Sakaguchi, Hiroaki Mohri, Yuzuru Ninoyu, Akihiro Goto, Taro Yamaguchi, Yoshitaka Hishikawa, Michiyuki Matsuda, Naoaki Saito, Takehiko Ueyama (2023) Dispensable role of Rac1 and Rac3 after cochlear hair cell specification., Journal of molecular medicine (Berlin, Germany)

Published in 2023 May 19 (Electronic publication in May 19, 2023, midnight )

(Abstract) Rac small GTPases play important roles during embryonic development of the inner ear; however, little is known regarding their function in cochlear hair cells (HCs) after specification. Here, we revealed the localization and activation of Racs in cochlear HCs using GFP-tagged Rac plasmids and transgenic mice expressing a Rac1-fluorescence resonance energy transfer (FRET) biosensor. Furthermore, we employed Rac1-knockout (Rac1-KO, Atoh1-Cre;Rac1(flox/flox)) and Rac1 and Rac3 double KO (Rac1/Rac3-DKO, Atoh1-Cre;Rac1(flox/flox);Rac3(-/-)) mice, under the control of the Atoh1 promoter. However, both Rac1-KO and Rac1/Rac3-DKO mice exhibited normal cochlear HC morphology at 13 weeks of age and normal hearing function at 24 weeks of age. No hearing vulnerability was observed in young adult (6-week-old) Rac1/Rac3-DKO mice even after intense noise exposure. Consistent with prior reports, the results from Atoh1-Cre;tdTomato mice confirmed that the Atoh1 promoter became functional only after embryonic day 14 when the sensory HC precursors exit the cell cycle. Taken together, these findings indicate that although Rac1 and Rac3 contribute to the early development of sensory epithelia in cochleae, as previously shown, they are dispensable for the maturation of cochlear HCs in the postmitotic state or for hearing maintenance following HC maturation. KEY MESSAGES: Mice with Rac1 and Rac3 deletion were generated after HC specification. Knockout mice exhibit normal cochlear hair cell morphology and hearing. Racs are dispensable for hair cells in the postmitotic state after specification. Racs are dispensable for hearing maintenance after HC maturation.

Contact(s)
Takehiko Ueyama
Organization(s)
Kobe University , Biosignal Research Center
Image Data Contributors
Takehiko Ueyama
Quantitative Data Contributors
Takehiko Ueyama

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