Vol. 62, 2023
Identification of Sexually
Dimorphic Genes in Pectoral Fin as Molecular Markers for Assessing the
Sex of Japanese Silver Eels (Anguilla
Hsu1, Chia-Hsien Chuang2, I-Hsuan Lu2,
Chung-Yen Lin2, and Yu-San Han1,*
of Fisheries Science, College of Life Science, National Taiwan
University, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
*Correspondence: E-mail: email@example.com (Han).
E-mail: firstname.lastname@example.org (Hsu)
2Institute of Information Science, Academia Sinica,
Taipei, Taiwan. E-mail: email@example.com (Chuang);
firstname.lastname@example.org (Lu); email@example.com (Lin)
(Received 2 June 2022 / Accepted 25
October 2022 / Published -- 2023)
Communicated by John Wang
The Japanese eel is an important
aquaculture species in East Asia. However, seedlings for aquaculture
still rely on natural resources since commercial production of glass
eels is not yet possible. Confusion about the sex of silver eels is one
of the factors affecting the success rate of artificial maturation.
This study sought to devise a harmless method to precisely assess the
sex of silver eels. Partial pectoral fins were collected from females
and males and the total RNA was extracted for transcriptomic analysis
to identify sexually dimorphic genes as molecular markers for sex
typing. An online database was constructed to integrate the annotations
of transcripts and perform comparative transcriptome analysis. This
analysis identified a total of 29 candidate sexually dimorphic genes.
Ten were selected for real-time quantitative polymerase chain reaction
(RT-qPCR) to validate the transcriptomic data and evaluate their
feasibility as markers. The transcriptomic analysis and RT-qPCR data
implicated three potential markers (LOC111853410,
kera, and dcn) in sex typing. The expression
of LOC111853410 was higher in
females than in males. In contrast, the expression of kera and dcn was higher in males than in
females. The analysis of ΔCT values of three markers has
determined their inferred thresholds of ΔCT that can be
applied to the sex typing of Japanese eel. The results suggested that a
silver eel with the pectoral fin having the ΔCT of LOC111853410 < 11.3, the ΔCT
of kera > 11.4, or the ΔCT
of dcn > 6.5 can be
assessed as a female. The male sex of adult or juvenile eels was
assessed by the ΔCT of LOC111853410
> 11.3, the ΔCT of kera
< 11.4, or the ΔCT of dcn
< 6.5 in their pectoral fins. The molecular functions of these
markers and the biological significance of their differential
expression between sexes require further exploration.
Key words: Comparative transcriptome analysis,
Japanese eel, Pectoral fin, Sex typing, Sexually dimorphic genes.
Citation: Hsu HY, Chuang CH, Lu IH, Lin
CY, Han YS. 2023. Identification of sexually dimorphic genes in
pectoral fin as molecular markers for assessing the sex of Japanese
silver eels (Anguilla japonica).
Zool Stud 62:02.
materials: Table S1丨 Table S2丨Table S3丨Table S4丨Fig. S1丨Fig. S2丨Fig. S3