PUBLICATION

Duplication and subfunctionalisation of the general transcription factor IIIA (gtf3a) gene in teleost genomes, with ovarian specific transcription of gtf3ab

Authors
Rojo-Bartolomé, I., Santana de Souza, J.E., Diaz de Cerio, O., Cancio, I.
ID
ZDB-PUB-200131-9
Date
2020
Source
PLoS One   15: e0227690 (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Animals
  • Cichlids/genetics
  • Cichlids/growth & development
  • Cichlids/metabolism
  • Disorders of Sex Development/genetics
  • Evolution, Molecular
  • Female
  • Fish Proteins/genetics
  • Fish Proteins/metabolism
  • Gene Duplication
  • Male
  • Oogenesis/genetics
  • Ovary/metabolism*
  • Phylogeny
  • Sex Characteristics
  • Sex Differentiation/genetics
  • Synteny
  • Transcription Factor TFIIIA/genetics*
  • Transcription Factor TFIIIA/metabolism
  • Zebrafish/genetics*
  • Zebrafish/growth & development
  • Zebrafish/metabolism
  • Zebrafish Proteins/genetics*
  • Zebrafish Proteins/metabolism
PubMed
31999691 Full text @ PLoS One
Abstract
Fish oogenesis is characterised by a massive growth of oocytes each reproductive season. This growth requires the stockpiling of certain molecules, such as ribosomal RNAs to assist the rapid ribosomal assembly and protein synthesis required to allow developmental processes in the newly formed embryo. Massive 5S rRNA expression in oocytes, facilitated by transcription factor 3A (Gtf3a), serves as marker of intersex condition in fish exposed to xenoestrogens. Our present work on Gtf3a gene evolution has been analysed in silico in teleost genomes and functionally in the case of the zebrafish Danio rerio. Synteny-analysis of fish genomes has allowed the identification of two gtf3a paralog genes, probably emerged from the teleost specific genome duplication event. Functional analyses demonstrated that gtf3ab has evolved as a gene specially transcribed in oocytes as observed in Danio rerio, and also in Oreochromis niloticus. Instead, gtf3aa was observed to be ubiquitously expressed. In addition, in zebrafish embryos gtf3aa transcription began with the activation of the zygotic genome (~8 hpf), while gtf3ab transcription began only at the onset of oogenesis. Under exposure to 100 ng/L 17β-estradiol, fully feminised 61 dpf zebrafish showed transcription of ovarian gtf3ab, while masculinised (100 ng/L 17α-methyltestosterone treated) zebrafish only transcribed gtf3aa. Sex related transcription of gtf3ab coincided with that of cyp19a1a being opposite to that of amh and dmrt1. Such sex dimorphic pattern of gtf3ab transcription was not observed earlier in larvae that had not yet shown any signs of gonad formation after 26 days of oestradiol exposure. Thus, gtf3ab transcription is a consequence of oocyte differentiation and not a direct result of estrogen exposure, and could constitute a useful marker of gonad feminisation and intersex condition.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping