DOI: 10.5061/dryad.69p8cz9f7
title: Seasonal environmental change and sex change in a cnidarian

description: 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.
description: # Seasonal environmental change and sex change in a cnidarian Dataset DOI:
 [10.5061/dryad.69p8cz9f7](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