# A 300 bp non-coding repeat sequence has co-evolved with the ced-2/CRKII-set-23/SETMAR genes of nematodes

## TL;DR

A 300 bp non-coding repeat sequence is found to co-evolve with specific genes in nematodes, suggesting a regulatory role.

## Contribution

The discovery of a conserved non-coding repeat sequence linked to nematode gene operons and its potential regulatory function.

## Key findings

- A ~300 nucleotide non-coding repeat is found four times in C. elegans at the ced-2/CRKII-set-23/SETMAR operon.
- The repeats are conserved across nematode species, including C. briggsae, C. brenneri, and B. malayi.
- The repeats are more conserved between C. elegans and B. malayi than the CED-2/CRKII coding sequences.

## Abstract

Highly conserved non-coding repeats may encode sequences with regulatory functions. We report a ~300 nucleotide non-coding repeat found four times in

C. elegans
,

and exclusively at the

ced-2
/CRKII-
set-23
/SETMAR

operon. Comparative analysis across nematodes, including

C. briggsae
,
C. brenneri

, and distantly related
B. malayi
, shows that these repeats are conserved at all

ced-2
/CRKII-
set-23
/SETMAR

loci. Furthermore, between

C. elegans

and
B. malayi
these repeats are more highly conserved than the
CED-2
/CRKII coding sequences. These findings suggest the repeats are conserved regulatory modules coordinating
CED-2
and
SET-23
expression. Supporting this idea, the repeats partially resemble miRNA precursors.