# Gonadal Transcriptome Analysis Reveals the lncRNA–mRNA Pair in Sea Cucumber Holothuria leucospilota

## TL;DR

This study explores lncRNA and mRNA interactions in sea cucumber gonads to understand reproductive regulation in marine invertebrates.

## Contribution

The study identifies specific lncRNA–mRNA pairs in sea cucumber gonads and their potential roles in reproductive regulation.

## Key findings

- Certain lncRNA–mRNA pairs show sex-specific expression patterns in sea cucumber gonads.
- Predicted lncRNA–mRNA interactions suggest roles in gonad development pathways.
- The findings provide insights into reproductive regulation in marine invertebrates.

## Abstract

Background/Objectives: Long non-coding RNA (lncRNA) was structurally similar to mRNAs, yet they could not be translated into proteins. While an increasing number of reports have systematically identified and described lncRNA in model species, information about non-model species remains scarce. Sea cucumber Holothuria leucospilota could be used for both medicinal and food purposes, which have high economic value, gradually attracting the attention of researchers. Methods: In this research, we constructed lncRNA library and compared the difference in lncRNA expression profiles between testis and ovary of sea cucumber H. leucospilota. To elucidate the molecular interactions between lncRNA and mRNA, we computationally predicted potential complementary binding sites through analysis of both cis- and trans-acting antisense mechanisms. Subsequent Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses demonstrated that the identified target genes are potentially involved in the regulatory pathways governing gonad development. Results: Quantitative reverse transcription PCR analysis showed that MSTRG.32831.1-sox9 and MSTRG.57315.1-mthfr exhibited a high expression pattern in testis; while MSTRG.11041.1-mafa and MSTRG.11074.1-macf1 showed a high expression pattern in the ovary. Conclusions: Deciphering lncRNA–mRNA expression patterns may uncover fundamental principles governing reproductive regulation in marine invertebrates. This discovery not only deepens understanding in this field but also provides valuable comparative insights for developmental biology.