Identification and Characterization of a PRDM14 Homolog in Japanese Flounder (Paralichthys olivaceus).

Lin Fan,Jiajun Jiang,Xubo Wang,Jinxiang Liu,Quanqi Zhang,Zan Li,Jinning Gao,Huayu Song,Likun Yang,Yan Chen

doi:10.3390/ijms16059097

Abstract

PRDM14 is a PR (PRDI-BF1-RIZ1 homologous) domain protein with six zinc fingers and essential roles in genome-wide epigenetic reprogramming. This protein is required for the establishment of germ cells and the maintenance of the embryonic stem cell ground state. In this study, we cloned the full-length cDNA and genomic DNA of the Paralichthys olivaceus prdm14 (Po-prdm14) gene and isolated the 5' regulatory region of Po-prdm14 by whole-genome sequencing. Peptide sequence alignment, gene structure analysis, and phylogenetic analysis revealed that Po-PRDM14 was homologous to mammalian PRDM14. Results of real-time quantitative polymerase chain reaction amplification (RT-qPCR) and in situ hybridization (ISH) in embryos demonstrated that Po-prdm14 was highly expressed between the morula and late gastrula stages, with its expression peaking in the early gastrula stage. Relatively low expression of Po-prdm14 was observed in the other developmental stages. ISH of gonadal tissues revealed that the transcripts were located in the nucleus of the oocytes in the ovaries but only in the spermatogonia and not the spermatocytes in the testes. We also presume that the Po-prdm14 transcription factor binding sites and their conserved binding region among vertebrates. The combined results suggest that Po-PRDM14 has a conserved function in teleosts and mammals.

Highlights

PRDM (PRDI-BF1-RIZ1 homologous domain-containing) family members are characterized on the basis of a conserved N-terminal PR domain and several C-terminal Krüppel-type zinc finger motifs.The PR domain was first reported as the PRDI-BF1-RIZ1 homologous domain [1], whose name was derived from the two members: PRDI-BF1 and RIZ1(retinoblastoma-interacting zinc finger protein 1) [2,3]
A comparison of cDNA and genomic sequences shows that Po-prdm14 contains nine exons (Figure 2), which differs from the gene structure of most of the other known species
The PR domain diverged from the SET domain, which defines a large group of histone methyltransferases (HMTs)

Summary

Introduction

PRDM (PRDI-BF1-RIZ1 homologous domain-containing) family members are characterized on the basis of a conserved N-terminal PR domain and several C-terminal Krüppel-type zinc finger motifs.The PR domain was first reported as the PRDI-BF1-RIZ1 homologous domain [1], whose name was derived from the two members: PRDI-BF1 (positive regulatory domain I-binding factor 1) and RIZ1(retinoblastoma-interacting zinc finger protein 1) [2,3]. PRDM (PRDI-BF1-RIZ1 homologous domain-containing) family members are characterized on the basis of a conserved N-terminal PR domain and several C-terminal Krüppel-type zinc finger motifs. The PR domain was first reported as the PRDI-BF1-RIZ1 homologous domain [1], whose name was derived from the two members: PRDI-BF1 (positive regulatory domain I-binding factor 1) and RIZ1. PRDI-BF1 is referred to as PRDM1 and RIZ1 as PRDM2 [4]. The additional PRDM family members were subsequently named. The PR domain has a 20%–30% amino-acid identity to the SET (suppressor of variegation 3–9, enhancer of zeste, and trithorax) domain, which is a conserved methyltransferase domain found in all known lysine histone methyltransferases (HMTs) that methylate histone tails [5,6,7,8].

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