Seasonal environmental change and sex change in a cnidarian
Data files
Jun 11, 2025 version files 483.32 MB
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holi_sex_trinity.Trinity.fasta
348.12 MB
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holi_sex.isoform.counts.matrix
81.84 MB
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HydraoligactisSexChangeFinal.xlsx
34.25 KB
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README.md
2.78 KB
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RNASeq2019_transcript_goTerms.txt
53.33 MB
Abstract
Here, we investigated the effect of seasonal temperature fluctuations on the expression of sex-related genes and sex change in the gonochoristic freshwater cnidarian, brown hydra (Hydra oligactis). Individuals of this species reproduce clonally throughout much of the year but switch to sexual reproduction when the temperature decreases in autumn. After sexual reproduction, some individuals can revert to clonality again. We found that clonal offspring derived from these individuals had a relatively high rate of female-to-male transition. The sexual stage was most differentiated in terms of gene expression, with a large number of genes involved in cellular differentiation and gametogenesis differentially expressed between males and females undergoing gamete production, while asexual individuals belonging to the male and female strains were transcriptomically nearly identical following sexual reproduction.
Dataset DOI: 10.5061/dryad.69p8cz9f7
Description of the data and file structure
This repository consists of two parts:
Part 1. Observations of the sexual phenotype of 6 hydra clonal lineages exposed to seasonal temperature changes.
Part 2. de novo transcriptome assembly and gene expression data from 2 H. oligactis strains (C2/7 and X11/14) at 5 points along their life cycle:
- group B: freshly detached buds cultured at 18°C
- group A: 3-week-old adults cultured at 18°C, reproducing asexually
- group C: adults two days after being transferred to 8°C, still asexual
- group D: adults two weeks after being transferred to 8°C, undergoing gonadogenesis
- group E: asexual individuals at 8°C obtained from sexual individuals that survived gonadogenesis
Files and variables
File: HydraoligactisSexChangeFinal.xlsx
Description: Observations of phenotypic sex in six strains exposed to seasonal temperature fluctuations. Three strains (M26/9/10, X11/14, T3/1) were originally female, i.e., they had a constant capacity to produce female gametes when cultured on the long term at 18 °C. Three other strains (M83/4, C2/7, T3/2) were originally male, i.e., they had a constant capacity to produce male gametes when cultured in the long term at 18 °C.
Variables
- ID: individual identifier
- strain: strain ID, one of: M26/9/10, X11/14, T3/1, M83/4, C2/7, T3/2
- CoolingDate: date when individual was transferred to low temperature to detect phenotypic sex
- SexStart: date when gonads were first observed
- sex: developed sex, female or male; asex or died
- result: one of SC (sex changed), C (expected sex observed, control), not relevant (sex not observed)
File: holi_sex.isoform.counts.matrix
Description: Transcript expression counts, as estimated by Trinity/salmon. Rows denote transcripts, columns denote samples. Sample names are as follows: the first letter denotes strain (C for C2/7, X for X11/14), the second letter denotes group (B: freshly detached buds cultured at 18°C; A: 3 week old adults cultured at 18°C, reproducing asexually; C: adults two days after being transferred to 8°C, still asexual; D: adults two weeks after being transferred to 8°C, undegoing gonadogenesis; E: asexual individuals at 8°C obtained from sexual individuals that survived gonadogenesis). The final numbers/letters are individual sample IDs.
File: holi_sex_trinity.Trinity.fasta
Description: Fasta file containing de novo transcriptome sequences
File: RNASeq2019_transcript_goTerms.txt
Description: Gene Ontology terms associated with each transcript
Code/software
Excel/LibreOffice / text editor