Characterization of a new oda3 allele, oda3-6, defective in assembly of the outer dynein arm-docking complex in Chlamydomonas reinhardtii.

Jason M Brown,Fan Yang,Chasity Scarbrough,Maureen Wirschell,George B Witman,Matthew Mosley,Yuqing Hou,Daniela Montes-Berrueta,Md A Motaleb

doi:10.1371/journal.pone.0173842

Abstract

We have used an insertional mutagenesis approach to generate new C. reinhardtii motility mutants. Of 56 mutants isolated, one is a new allele at the ODA3 locus, called oda3-6. Similar to the previously characterized oda3 alleles, oda3-6 has a slow-jerky swimming phenotype and reduced swimming speed. The oda3-6 mutant fails to assemble the outer dynein arm motor and outer dynein arm—docking complex (ODA-DC) in the ciliary axoneme due to an insertion in the 5’ end of the DCC1 gene, which encodes the DC1 subunit of the ODA-DC. Transformation of oda3-6 with the wild-type DCC1 gene rescues the mutant swimming phenotype and restores assembly of the ODA-DC and the outer dynein arm in the cilium. This is the first oda3 mutant to be characterized at the molecular level and is likely to be very useful for further analysis of DC1 function.

Highlights

IntroductionCilia and flagella (terms here used interchangeably) are highly conserved organelles with both motile and sensory functions
Cilia and flagella are highly conserved organelles with both motile and sensory functions
Using antibodies to the outer dynein arms (ODA) intermediate chain IC2, we find that assembly of the ODAs is greatly reduced in the JB09H1 mutant

Summary

Introduction

Cilia and flagella (terms here used interchangeably) are highly conserved organelles with both motile and sensory functions. Defects in assembly or function of cilia lead to a class of diseases known as ciliopathies—pleiotropic pathologies that affect development and adult human organ function [1,2,3,4,5,6,7,8,9,10]. Studies of cilia in C. reinhardtii, and the dynein motors that drive their movement, have been instrumental in the identification of numerous ciliopathy genes [11]. C. reinhardtii provides an excellent model for studies of dynein subunit composition, assembly and regulatory mechanisms. There are two main classes of ciliary (or axonemal) dynein motors: the outer dynein arms (ODA) and the inner dynein arms (IDA).

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Conclusion