Peer Review #1 of "Origin and evolution of GATA2a and GATA2b in teleosts: insights from tongue sole, Cynoglossus semilaevis (v0.2)" [peer_review]

2016 unpublished
Following the two rounds of whole-genome duplication that occurred during deuterostome evolution, a third genome duplication occurred in the lineage of teleost fish and is considered to be responsible for much of the biological diversification within the lineage. GATA2, a member of GATA family of transcription factors, is an important regulator of gene expression in hematopoietic cell in mammals; yet the role of this gene or its putative paralogs in ray-finned fishes remains relatively unknown.
more » ... relatively unknown. Methods: In this study, we attempted to identify GATA2 sequences from the transcriptomes and genomes of multiple teleosts using the bioinformatic tools MrBayes, MEME, and PAML. Following identification, comparative analysis of genome structure, molecular evolution rate, and expression by real-time qPCR were used to predict functional divergence of GATA2 paralogs and their relative transcription in organs of female and male tongue soles (Cynoglossus semilaevis). Results: Two teleost GATA2 genes were identified in the transcriptomes of tongue sole and Japanese flounder (Paralichthysolivaceus). Synteny and phylogenetic analysis confirmed that the two genes likely originated from the teleostspecific genome duplication . Additionally, selection pressure analysis predicted these gene duplicates to have undergone purifying selection and possible divergent new functions. This was supported by differential expression pattern of GATA2a and GATA2b observed in organs of female and male tongue soles. Discussion: Our results indicate that two GATA2 genes originating from the first teleost-specific genome duplication have remained transcriptionally active in some fish species and have likely undergone neofunctionalization. This knowledge provides novel insights into the evolution of the teleost GATA2 genes and constituted important groundwork for further research on the GATA gene family. PeerJ reviewing PDF | (Manuscript to be reviewed 22 23 ABSTRACT 24 Background: Following the two rounds of whole-genome duplication that occurred during 25 deuterostome evolution, a third genome duplication occurred in the lineage of teleost fish and is 26 considered to be responsible for much of the biological diversification within the lineage. GATA2, 27 a member of GATA family of transcription factors, is an important regulator of gene expression 28 in hematopoietic cell in mammals; yet the role of this gene or its putative paralogs in ray-finned 29 fishes remains relatively unknown. 30 Methods: In this study, we attempted to identify GATA2 sequences from the transcriptomes and 31 genomes of multiple teleosts using the bioinformatic tools MrBayes, MEME, and PAML. 32 Following identification, comparative analysis of genome structure, molecular evolution rate, and 33 expression by real-time qPCR were used to predict functional divergence of GATA2 paralogs and 34 their relative transcription in organs of female and male tongue soles (Cynoglossus semilaevis). 35 Results: Two teleost GATA2 genes were identified in the transcriptomes of tongue sole and 36 Japanese flounder (Paralichthys olivaceus). Synteny and phylogenetic analysis confirmed that the 37 two genes likely originated from the teleost-specific genome duplication. Additionally, selection 38 pressure analysis predicted these gene duplicates to have undergone purifying selection and 39 possible divergent new functions. This was supported by differential expression pattern of 40 GATA2a and GATA2b observed in organs of female and male tongue soles. 41 Discussion: Our results indicate that two GATA2 genes originating from the first teleost-specific PeerJ reviewing PDF | (
doi:10.7287/peerj.1790v0.2/reviews/1 fatcat:xkje4uja7rdozayifj4qmxql7i