DOI: 10.5061/dryad.02v6wwqhm
title: Environmental cues in coral reproduction: Photoperiod and seawater temperature influence oocyte development in <em>Acropora tenuis</em>

description: In subtropical regions, a full gametogenesis cycle in corals takes 11-12
 months to complete. As such, the different stages of the gametogenesis
 process occur under differing light and seawater temperatures conditions
 over the course of one year. Here we show how photoperiod length and
 seawater temperature influence coral gametogenesis in the scleractinian
 coral Acropora tenuis using molecular and histological analyses. Changing
 the number of daylight hours showed that a longer photoperiod (14L:10D)
 significantly upregulated the germ cell genes Piwi. For seawater
 temperature, the effect was dependent on the stage of maturation; low
 seawater temperatures (21°C) were necessary for vitellogenesis in immature
 (non-vitellogenic) coral nubbins, and warming seawater temperatures
 (25-29°C) accelerated oocyte maturation in vitellogenic corals. These
 findings show that longer photoperiods in summer enhance germ cell
 activity, low seawater temperature during winter is essential for
 initiating yolk formation, and warmer temperatures during early summer
 trigger oocyte maturation in A. tenuis. Therefore, our findings indicate
 that photoperiod and seawater temperature play important roles in
 regulating gametogenesis in A. tenuis.
description: # Environmental cues in coral reproduction: Photoperiod and seawater
 temperature influence oocyte development in Acropora tenuis ## Description
 This dataset contains gene expression and histological measurements used
 to examine how photoperiod and seawater temperature influence oocyte
 development in the coral *Acropora tenuis*. It includes oocyte size
 measurements (micrometers, μm) obtained using ImageJ and quantitative PCR
 data for key reproductive and signaling genes (Cq values), collected under
 controlled light and temperature conditions. Temperature logger data
 (degrees Celsius, °C) for all experimental periods are also provided.
 Together, these data support analyses demonstrating that oocyte growth and
 vitellogenesis are regulated by seasonal changes in day length and
 seawater temperature, offering insights into the timing of gametogenesis
 and spawning in *A. tenuis* from Okinawa, Japan. ## File List and
 Descriptions ***Photoperiod Experiment***
 **01_Photoperiod_Exp._(Oocyte_diameter__RAW).csv** Measurements of oocyte
 diameter (µm) under 10h, 12h, and 14h light conditions. Each oocyte was
 measured along two axes: **Length**, representing the maximum oocyte
 dimension, and **Width**, representing the dimension perpendicular to the
 maximum length. The oocyte diameter was not calculated in this dataset. To
 derive a standardized estimate of oocyte size, users should calculate the
 **geometric mean** of the two measurements: for example, R script,
 data$diameter &lt;- sqrt(data$Length * data$Width).
 **02_Photoperiod_Exp._qPCR_RAW_Cq_values.csv** Raw Cq values from qPCR
 assays conducted on coral samples exposed to different photoperiod
 treatments. The dataset includes both biological and technical replicates.
 Each gene is represented as a separate column: Vasa, Piwi, VG1, VG2,
 LDLR1, and two housekeeping genes (β-actin and ef1a). No normalization has
 been applied to these data. Users can calculate relative expression using
 the ΔΔCq method, normalized to housekeeping genes (β-actin or ef1a).
 **03_Photoperiod_Exp._temperature_logger_(10h_tank).csv** Time-stamped
 seawater temperature recordings (°C) collected from the experimental tank
 maintained under a 10-hour light photoperiod. Data were logged at 2-hour
 intervals using a HOBO data logger throughout the entire experimental
 period to monitor thermal conditions and ensure consistency among
 treatments. These values can be used to verify temperature stability and
 to compare environmental conditions across tanks in related files.
 **04_Photoperiod_Exp._temperature_logger_(12h_tank).csv** Same as above,
 for the 12-hour light treatment.
 **05_Photoperiod_Exp._temperature_logger_(14h_tank).csv** Same as above,
 for the 14-hour light treatment. 
 
 ***Seawater Temperature Experiment Phase 1***
 **06_SWT_Exp._1_(Oocyte_diameter_RAW).csv** Measurements of oocyte
 diameter (µm) under 21°C, 25°C, and 29°C SWT conditions. Each oocyte was
 measured along two axes: **Length**, representing the maximum oocyte
 dimension, and **Width**, representing the dimension perpendicular to the
 maximum length. The oocyte diameter was not calculated in this dataset. To
 derive a standardized estimate of oocyte size, users should calculate the
 **geometric mean** of the two measurements: for example, R script,
 data$diameter &lt;- sqrt(data$Length * data$Width).
 **07_SWT_Exp._1_qPCR_RAW_Cq_values.csv** Raw Cq values from qPCR assays
 conducted on coral samples exposed to different seawater temperature
 treatments. The dataset includes both biological and technical replicates.
 Each gene is represented as a separate column: Vasa, Piwi, VG1, VG2,
 LDLR1, and two housekeeping genes (β-actin and ef1a). No normalization has
 been applied to these data. Users can calculate relative expression using
 the ΔΔCq method, normalized to housekeeping genes (β-actin or ef1a).
 **08_SWT_Exp._1_temperature_logger_21_degree_tank.csv** Time-stamped
 seawater temperature recordings (°C) collected from the experimental tank
 maintained under a 21°C. Data were logged at 1-hour intervals using a HOBO
 data logger throughout the entire experimental period to monitor thermal
 conditions and ensure consistency among treatments. These values can be
 used to verify temperature stability and to compare environmental
 conditions across tanks in related files.
 **09_SWT_Exp._1_temperature_logger_25_degree_tank.csv** Same as above, for
 the 25°C tank. **10_SWT_Exp._1_temperature_logger_29_degree_tank.csv**
 Same as above, for the 29°C tank. 
 
 ***Seawater Temperature Experiment Phase 2***
 **11_SWT_Exp._2_(Oocyte_diameter_RAW).csv** Measurements of oocyte
 diameter (µm) under 21°C, 25°C, and 29°C SWT conditions. Each oocyte was
 measured along two axes: **Length**, representing the maximum oocyte
 dimension, and **Width**, representing the dimension perpendicular to the
 maximum length. The oocyte diameter was not calculated in this dataset. To
 derive a standardized estimate of oocyte size, users should calculate the
 **geometric mean** of the two measurements: for example, R script,
 data$diameter &lt;- sqrt(data$Length * data$Width).
 **12_SWT_Exp._2_qPCR_RAW_Cq_values.csv** Raw Cq values from qPCR assays
 conducted on coral samples exposed to different seawater temperature
 treatments. The dataset includes both biological and technical replicates.
 Each gene is represented as a separate column: VG1, VG2, LDLR1, Mos1,
 Mos2, Mos3, Mapk1, Mapk2, Hist2B, and two housekeeping genes (β-actin and
 ef1a). No normalization has been applied to these data. Users can
 calculate relative expression using the ΔΔCq method, normalized to
 housekeeping genes (β-actin or ef1a).
 **13_SWT_Exp._2_temperature_logger_21_degree_tank.csv** Time-stamped
 seawater temperature recordings (°C) collected from the experimental tank
 maintained under a 21°C. Data were logged at 1-hour intervals using a HOBO
 data logger throughout the entire experimental period to monitor thermal
 conditions and ensure consistency among treatments. These values can be
 used to verify temperature stability and to compare environmental
 conditions across tanks in related files.
 **14_SWT_Exp._2_temperature_logger_25_degree_tank.csv** Same as above, for
 the 25°C tank. **15_SWT_Exp._2_temperature_logger_29_degree_tank.csv**
 Same as above, for the 29°C tank. 
 
 ***Statistical Analysis and Scripts***
 **16_Statistical_Data_Analysis.xlsx** This file contains summary
 statistics and results from hypothesis testing performed on oocyte
 diameter and gene expression across all experiments. Analyses include
 ANOVA, blocked-ANOVA, and Kruskal–Wallis tests, followed by post hoc
 pairwise comparisons (*p* &lt; 0.05 considered significant). Statistically
 different groups are indicated by different letters or symbols (*).
 **17_Rscript_statistics.xlsx** This file contains the R scripts used to
 conduct statistical analyses for this study, including assumption testing,
 the execution of ANOVA, blocked-ANOVA, Kruskal–Wallis tests, and post hoc
 comparisons. **Notes** * Oocyte diameter is measured in micrometers (µm).
 * Temperature is recorded in degrees Celsius (°C). * Cq values come from
 qPCR using SYBR Green chemistry. * Missing or failed data are marked as
 NA.