DOI: 10.5061/dryad.mkkwh717f
title: Fertility decline in Aedes aegypti mosquitoes is associated with reduced maternal transcript deposition and does not depend on female age

description: Female mosquitoes undergo multiple rounds of reproduction known as
 gonotrophic cycles. A gonotrophic cycle spans the period from blood meal
 intake to egg laying. Nutrients from vertebrate host blood are necessary
 for completing egg development. During oogenesis, a female pre-packages
 mRNA into her oocytes, and these maternal transcripts drive the first two
 hours of embryonic development before zygotic genome activation. In this
 study, we profiled transcriptional changes in 1-2 hour-old Aedes
 aegypti embryos across two gonotrophic cycles. We found that
 homeotic genes which are regulators of embryogenesis are downregulated in
 embryos from the second gonotrophic cycle. Interestingly, embryos produced
 by Ae. aegypti females progressively reduced their
 ability to hatch as the number of gonotrophic cycles increased. We show
 that this fertility decline is due to increased reproductive output and
 not the mosquitoes’ age. Moreover, we found a similar decline in fertility
 and fecundity across three gonotrophic cycles in Ae. albopictus.
 Our results are useful for predicting mosquito population dynamics to
 inform vector control efforts.
description: <em>Transcriptomic data processing and
 analysis</em> RNA sequencing (RNA-seq) data for
 1-2hrs old wild-type <em>Ae</em>. <em>aegypti</em>
 embryos were retrieved from the transcriptome reported in our previous
 study [1]. Each library read was trimmed to remove the adapter sequence
 and then mapped to gene models from the AaegL5.0 genome. Upon mapping,
 transcript level abundance was determined from mapped reads using
 tximport. Principal component and differential gene expression analyses
 were performed on read counts using R’s shiny DEBrowser. Differential
 expression was calculated using Deseq2 at a corrected FDR of α &lt;
 0.01. Gene ontology (GO) enrichment was performed on differentially
 expressed genes at α &lt; 0.01 using the bioinformatics resources on
 vectorbase.org, and redundant or obsolete GO terms were removed.
   <em>Fecundity and fertility
 assays</em> To determine fecundity, the number of
 eggs deposited per female, 5–7-day old, mated females were starved on
 water overnight and then provided with a blood meal to repletion as
 described above. Fifty engorged females were transferred to a fresh cage
 and maintained on a 10% sucrose solution. 72-96hrs post blood meal,
 females were cold-anaesthetized and individually prepared for oviposition
 in a 24-well plate as previously described. Females were allowed to lay
 eggs over a period of 24 hours and individuals who failed to lay eggs were
 removed from the experiment. Upon egg collection, females were returned to
 the rearing cage with unlimited access to 10% sucrose solution and allowed
 to recover for 24hrs after which they were prepared for the second round
 of egg collection. Egg papers were kept moist for an additional 3-5 days
 post-collection and the number of eggs laid by individual females was
 subsequently counted. To determine fertility, the percentage of eggs that
 hatched into larvae, 5–7-day old eggs were hatched in individual 50mL cups
 containing DI water with dissolved TetraMin powder over a period of 3 days
 after which hatched larvae were counted. The same protocol was used in all
 experiments except in the delayed gonotrophic assay where some females
 were provided with their first blood meal at 20 days old. All experiments
 were conducted in triplicate with different mosquito-rearing
 cohorts. <em>1. David OG, Sanchez KM, Arce A V.,
 Costa-da-Silva AL, Bellantuono AJ, DeGennaro M. 2023 Fertility decline in
 female mosquitoes is regulated by the orco olfactory co-receptor. iScience
 <strong>26</strong>, 106883.
 (doi:10.1016/j.isci.2023.106883)</em>
description: # Fertility decline in *Aedes aegypti* mosquitoes is associated with
 reduced maternal transcript deposition and does not depend on female age
 [https://doi.org/10.5061/dryad.mkkwh717f](https://doi.org/10.5061/dryad.mkkwh717f) The dataset includes transcriptome analysis of *Aedes aegypti* early embryos. The raw sequencing reads of this dataset are available for download at the NCBI Sequence Read Archive (SRA) and are associated with BioProject ID PRJNA957289. The dataset also contains information on *Aedes aegypti* and *Aedes albopictus* mosquito egg deposition rate and egg hatch rate over three reproductive cycles (gonotrophic cycles). The data is presented on an Excel spreadsheet with multiple tabs: * RNA-seq sample metadata (data related to Figure 2) * RNA-seq read counts (data related to Figure 2) * Downregulated genes (data related to Figure 2) * Upregulated genes (data related to Figure 2) * Figure 1b (raw data presented in figure 1b, percent eggs hatched/female for *Ae. aegypti* Gonotrophic Cycle 1, *Ae. aegypti* Gonotrophic Cycle 2, and *Ae. aegypti* Gonotrophic Cycle 3) * Figure 1c (raw data presented in figure 1c, percent eggs laid/female for *Ae. aegypti* Gonotrophic Cycle 1, *Ae. aegypti* Gonotrophic Cycle 2, and *Ae. aegypti* Gonotrophic Cycle 3) * Figure 1d (raw data presented in figure 1d, percent eggs hatched/female for *Ae. albopictus* Gonotrophic Cycle 1, *Ae. albopictus* Gonotrophic Cycle 2, and *Ae.* *albopictus* Gonotrophic Cycle 3) * Figure 1e (raw data presented in figure 1e, percent eggs laid/female for *Ae. albopictus* Gonotrophic Cycle 1, *Ae. albopictus* Gonotrophic Cycle 2, and *Ae.* *albopictus* Gonotrophic Cycle 3) * Figure 1f (raw data presented in figure 1f, percent eggs hatched/female for *Ae. aegypti* Delayed Gonotrophic Cycle 1, *Ae. aegypti* Gonotrophic Cycle 1 *Ae. aegypti* Gonotrophic Cycle 2, and *Ae. aegypti* Gonotrophic Cycle 3) * Figure 1g (raw data presented in figure 1g, percent eggs laid/female for *Ae. aegypti* Delayed Gonotrophic Cycle 1, *Ae. aegypti* Gonotrophic Cycle 1 *Ae. aegypti* Gonotrophic Cycle 2, and *Ae. aegypti* Gonotrophic Cycle 3)