Katanin-like protein Katnal2 is required for ciliogenesis and brain development in Xenopus embryos

Abstract

Microtubule remodeling is critical for cellular and developmental processes underlying morphogenetic changes and for the formation of many subcellular structures. Katanins are conserved microtubule severing enzymes that are essential for spindle assembly, ciliogenesis, cell division, and cellular motility. We have recently shown that a related protein, Katanin-like 2 (KATNAL2), is similarly required for cytokinesis, cell cycle progression, and ciliogenesis in cultured mouse cells. However, its developmental expression pattern, localization, and in vivo role during organogenesis have yet to be characterized. Here, we used Xenopus embryos to reveal that Katnal2 (1) is expressed broadly in ciliated and neurogenic tissues throughout embryonic development; (2) is localized to basal bodies, ciliary axonemes, centrioles, and mitotic spindles; and (3) is required for ciliogenesis and brain development. Since human KATNAL2 is a risk gene for autism spectrum disorders, our functional data suggest that Xenopus may be a relevant system for understanding the relationship of mutations in this gene to autism and the underlying molecular mechanisms of pathogenesis.

The LisH Domain-Containing N-Terminal Fragment is Important for the Localization, Dimerization, and Stability of Katnal2 in Tetrahymena

“…Additionally, Katnal2 was detected in primary cilia along their entire length [5,6]. Similar Katnal2 localization was observed in Xenopus XL177 cells assembling primary cilia [7]. In the multiciliated cells of Xenopus embryonic epidermis, Katnal2 localizes to the basal bodies and along the axoneme of the motile cilia [7].…”

“…Similar Katnal2 localization was observed in Xenopus XL177 cells assembling primary cilia [7]. In the multiciliated cells of Xenopus embryonic epidermis, Katnal2 localizes to the basal bodies and along the axoneme of the motile cilia [7]. In the unicellular parasites Trypanosoma brucei and Leishmania major, ectopically expressed Katnal2 localizes to flagella, especially at the base and the tip, and its expression reduces the length of flagella [8].…”

Modern human alleles differentially regulate gene expression across brain regions: implications for brain evolution

“…When listed by number of occurrences, the gene that accumulates more variability from eQTL regulation is METTL18 (296 SNPs), followed by METTL14 (72 SNPs, all affecting gene cis-regulation in the cerebellum), POLI (47), a DNA repair gene [Jain et al, 2017], and KATNAL2 (41), a gene implicated in ciliogenesis and neurodevelopment in Xenopus [Willsey et al, 2018]. The full list of occurrences per gene can be found in Supp.…”

Advancing genetic and genomic technologies deepen the pool for discovery in Xenopus tropicalis

“…X. tropicalis tadpoles have proven to be an outstanding high‐throughput model for this purpose, with considerable advantages in time and cost over mice . CRISPR‐mediated mutagenesis of candidate genes is rapid and efficient in F 0 animals, and gene products can be independently knocked down by morpholino oligonucleotides, allowing rapid orthogonal approaches to define the requirement for a gene in developmental processes such as autism, heart development, albinism, and craniofacial development . A uniquely powerful feature of Xenopus is that these reagents can be delivered to just one blastomere of the two‐cell embryo to inhibit gene function only on one half of the embryo, providing a contralateral control and allowing investigation of cell autonomy.…”

“…34,35 CRISPR-mediated mutagenesis of candidate genes is rapid and efficient in F 0 animals, and gene products can be independently knocked down by morpholino oligonucleotides, allowing rapid orthogonal approaches to define the requirement for a gene in developmental processes such as autism, heart development, albinism, and craniofacial development. [36][37][38][39] A uniquely powerful feature of Xenopus is that these reagents can be delivered to just one blastomere of the two-cell embryo to inhibit gene function only on one half of the embryo, providing a contralateral control and allowing investigation of cell autonomy. Another powerful genetic approach that can be carried out within days in the F 0 animal is to use CRISPR and/or morpholino knockdown to create a genetically depleted background for the factor of interest, followed by a rescue injections with either the wildtype or patient allele of the factor, allowing one to specifically investigate the functionality of patient gene versions without requiring generations of breeding or homologous recombination.…”