RT Journal Article SR Electronic T1 Lost in translation: egg transcriptome reveals molecular signature to predict developmental success and novel maternal-effect genes JF bioRxiv FD Cold Spring Harbor Laboratory SP 286815 DO 10.1101/286815 A1 Caroline T. Cheung A1 Thaovi Nguyen A1 Aurélie Le Cam A1 Amélie Patinote A1 Laurent Journot A1 Christelle Reynes A1 Julien Bobe YR 2018 UL http://biorxiv.org/content/early/2018/03/23/286815.abstract AB Background Good quality or developmentally competent eggs result in high survival of progeny. Previous research has shed light on factors that determine egg quality, however, large gaps remain. Initial development of the embryo relies on maternally-inherited molecules, such as transcripts, deposited in the egg, thus, they would likely reflect egg quality. We performed transcriptome analysis on zebrafish fertilized eggs of different quality from unrelated, wildtype couples to obtain a global portrait of the egg transcriptome to determine its association with developmental competence and to identify new candidate maternal-effect genes.Results Fifteen of the most differentially expressed genes (DEGs) were validated by quantitative real-time PCR. Gene ontology analysis showed that enriched terms included ribosomes and translation. In addition, statistical modeling using partial least squares regression and genetics algorithm also demonstrated that gene signatures from the transcriptomic data can be used to predict reproductive success. Among the validated DEGs, otulina and slc29a1a were found to be increased in good quality eggs and to be predominantly localized in the ovaries. CRISPR/Cas9 knockout mutants of each gene revealed remarkable subfertility whereby the majority of their embryos were unfertilizable. The Wnt pathway appeared to be dysregulated in the otulina knockout-derived eggs.Conclusions Our novel findings suggested that even in varying quality of eggs due to heterogeneous causes from unrelated wildtype couples, gene signatures exist in the egg transcriptome, which can be used to predict developmental competence. Further, transcriptomic profiling revealed two new potential maternal-effect genes that have essential roles in vertebrate reproduction.2-FCV2-fold cross validationcldn23claudin 23DEGsdifferentially expressed genesdrd3dopamine receptor D3FDRfalse discovery rateflvcr1feline leukemia subgroup C cellular receptor family, member 2agfpblue fluorescent proteinhpfhours post-fertilizationitih2inter-alpha-tryspin inhibitor heavy chain 2MBTmid-blastula transitionnpm2a and npm2bnucleoplasmin 2a/bnudt13nucleoside diphosphate linked moiety X-type 13otulinaOTU deubiquitinase with linear linkage specificity a, fam105baPLSpartial least square regressionpomt1protein-O-mannosyltransferase 1prkcqprotein kinase C, thetaqPCRquantitative real-time polymerase chain reactionRNA-seqRNA sequencingrpf2ribosome production factor 2 homolog (S. cerevisiae)rps27ribosomal protein S27 (isoform 2)rtn4ipreticulon 4 interacting protein 1slc29a1asolute carrier family 29, member 1aspon1bspondin 1bstra13stimulated by retinoic acid 13 homolog/centromere protein Xtk2thymidine kinase 2tspan7btetraspanin 7bU1U1 spliceosomal RNAWTwildtypeZGAzygotic genome activation