**5. Conclusions**

In this study, we performed a transcriptomic analysis on the olfactory epithelia of both male and female zebrafish using high-throughput RNA sequencing. We found the olfactory transcriptomes between males and females are highly similar, with only few genes displaying di fferentially expressed. Most of chemosensory receptor genes showed evidence of expression in the zebrafish olfactory epithelia, with a higher level of expression in males than in females. Collectively, these results provide a comprehensive catalog of the genes mediating olfactory perception and pheromone-evoked behavior in fish.

*Genes* **2020**, *11*, 592

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2073-4425/11/6/592/s1, Table S1: Summary of the RNA-seq datasets in olfactory mucosae from male and female zebrafish, Table S2: Expression estimates in the zebrafish olfactory epithelium. A dataset containing the raw and normalized expression values for all the genes in the zebrafish olfactory epithelium, Table S3: 312 and 333 most abundant genes account for 50% of the fragments obtained from the tissue for male and female, Table S4: Differential expression analysis between male and female samples. Genes with an FDR < 0.05 were considered significant, Table S5: Functional enrichment analysis for differentially expressed genes, Table S6: Differential alternative splicing events between male and female zebrafish olfactory epithelium, Table S7 Expression level of the chemosensory receptor genes.

**Author Contributions:** Conceptualization, L.Y.; formal analysis, Y.W., H.J. and L.Y.; funding acquisition, Y.W. and L.Y.; investigation, H.J.; writing—original draft, Y.W.; writing—review & editing, L.Y. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by grants from the National Natural Science Foundation of China (31702016) to Y.W. and from the National Natural Science Foundation of China (31972866) to L.Y.

**Acknowledgments:** We are grateful to the computational support from the Wuhan Branch, Supercomputing Center, Chinese Academy of Sciences, China.

**Conflicts of Interest:** The authors declare no conflict of interest.
