PUBLICATION

Lampreys, the jawless vertebrates, contain three Pax6 genes with distinct expression in eye, brain and pancreas

Authors
Ravi, V., Bhatia, S., Shingate, P., Tay, B.H., Venkatesh, B., Kleinjan, D.A.
ID
ZDB-PUB-191223-23
Date
2019
Source
Scientific Reports   9: 19559 (Journal)
Registered Authors
Bhatia, Shipra, Venkatesh, Byrappa
Keywords
none
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Animals, Genetically Modified
  • Brain/metabolism*
  • Evolution, Molecular
  • Eye/metabolism*
  • Lampreys/metabolism*
  • PAX6 Transcription Factor/chemistry
  • PAX6 Transcription Factor/metabolism*
  • Pancreas/innervation*
  • Transcription Factors/chemistry
  • Transcription Factors/metabolism*
  • Vertebrates/metabolism*
  • Zebrafish
PubMed
31863055 Full text @ Sci. Rep.
Abstract
The transcription factor Pax6 is crucial for the development of the central nervous system, eye, olfactory system and pancreas, and is implicated in human disease. While a single Pax6 gene exists in human and chicken, Pax6 occurs as a gene family in other vertebrates, with two members in elephant shark, Xenopus tropicalis and Anolis lizard and three members in teleost fish such as stickleback and medaka. However, the complement of Pax6 genes in jawless vertebrates (cyclostomes), the sister group of jawed vertebrates (gnathostomes), is unknown. Using a combination of BAC sequencing and genome analysis, we discovered three Pax6 genes in lampreys. Unlike the paired-less Pax6 present in some gnathostomes, all three lamprey Pax6 have a highly conserved full-length paired domain. All three Pax6 genes are expressed in the eye and brain, with variable expression in other tissues. Notably, lamprey Pax6α transcripts are found in the pancreas, a vertebrate-specific organ, indicating the involvement of Pax6 in development of the pancreas in the vertebrate ancestor. Multi-species sequence comparisons revealed only a single conserved non-coding element, in the lamprey Pax6β locus, with similarity to the PAX6 neuroretina enhancer. Using a transgenic zebrafish enhancer assay we demonstrate functional conservation of this element over 500 million years of vertebrate evolution.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping