Frontiers in Physiology (Jul 2020)

Molecular Characterization and Expression Profiling of Three Transformer-2 Splice Isoforms in the Redclaw Crayfish, Cherax quadricarinatus

  • Lina Cai,
  • Lina Cai,
  • Jianbo Zheng,
  • Yongyi Jia,
  • Zhimin Gu,
  • Zhimin Gu,
  • Shili Liu,
  • Meili Chi,
  • Shun Cheng

DOI
https://doi.org/10.3389/fphys.2020.00631
Journal volume & issue
Vol. 11

Abstract

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Sex determination/sex differentiation is determined by genetics, environmental factors, or the interactions of the two. The Transformer-2 (Tra-2) gene plays an important role in the sex determination cascade signal pathway in insects. In this study, the Tra-2 gene was isolated and characterized from the cDNA library of gonad tissues in the redclaw crayfish, Cherax quadricarinatus. Three splice variants were identified, designated as CqTra-2A, CqTra-2B, and CqTra-2C, and sequence analysis showed that they had a highly conserved RRM domain. Phylogenetic analysis was performed by the NJ method, and the results revealed that the Tra-2 protein of the redclaw crayfish was very closely related to those of Macrobrachium rosenbergii, Fenneropenaeus chinensis, and Macrobrachium nipponense. Real-time PCR analysis showed that the three isoforms were predominantly expressed in the ovary and gradually increased with embryonic development. Additionally, the expression pattern of CqTra-2 at different developmental stages was analyzed by qPCR and revealed that the phase of having a body length of 3 cm may be the key period for the sex differentiation of C. quadricarinatus. RNAi-targeting gene silencing further confirmed the function of CqTra-2 in sexual differentiation in redclaw crayfish. Our experimental data will contribute to understanding the mechanism of sex determination in crustaceans.

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