取りやめになった発表のアブストラクト「理研エピジェネティクスシンポジウム2020」

久しぶりの書き込みです。

新型コロナウイルスの影響で中止になった学会・研究会で発表する予定だった研究内容の要旨を記録として順に貼り付けていきます。


2月25、26日　理研エピジェネティクスシンポジウム2020　＠理研横浜キャンパス

Scaling of Hox gene clusters: what happened to shark and lamprey?

Shigehiro Kuraku¹, Kazuaki Yamaguchi¹, Tatsumi Kaori¹, Chiharu Tanegashima¹, Osamu Nishimura¹, Mitsutaka Kadota¹

1. Laboratory for Phyloinformatics, RIKEN BDR, Kobe

Hox genes play crucial roles in embryogenesis and are organized into four clusters (Hox A–D) in many osteichthyans (bony vertebrates). We previously sequenced the whole genome of a few shark species (Hara,et al., 2018. Nat. Ecol. Evol.2:1761-1771), and in their genomes, we found not only well-conserved Hox A, B and D clusters containing an array of Hox genes expressed in a temporally collinear manner, but also putative Hox C genes, although the entire Hox C cluster was long thought to have been lost from elasmobranch genomes. Remarkably, none of the identified putative shark Hox C genes comprised such a compact cluster as in other jawed vertebrates, spanning within a 100-kbp-long genomic region—for example, catshark Hoxc11 was flanked by a 50-kbp-long stretch containing no other Hox gene. Our analysis on embryonic expression patterns indicated that the identified elasmobranch Hox C genes are still under spatiotemporal transcriptional regulation, which is typically exerting on clustered Hox genes. These findings demonstrate that Hox C genes were not lost in a cluster-wide deletion event in the elasmobranch ancestor as proposed previously, and have eroded intermittently during elasmobranch evolution. Together, while the Hox A, B and D clusters exhibit the canonical, conservative nature even in elongated elasmobranch genomes, their Hox C cluster underwent remarkable lineage-specific, sequence-level modifications. This presentation will also cover the elongated, repeat-rich Hox clusters of lampreys, and discuss the significance of Hox cluster scaling in relation to the regulatory mechanisms.

Brownbanded bamboo shark Hox cluster structure

(Hara, etal., 2018. Nat. Ecol. Evol.2:1761-1771)