Abstract
Simple SummaryOxygen-binding proteins that mediate oxygen-binding for storage and consumption, to reduce energy, are very diverse in fish, depending on their habitats. In the present study, oxygen-binding protein gene expression in the skeletal muscle of 25 diverse fish species was examined by a meta-transcriptomic approach. By using RNAseq data, this is the first study to examine the high level of myoglobin, one of the oxygen-binding proteins, transcripts in pacu and loach fish that might be related to their high tolerance for the oxygen-deficient environment. In addition, this study presents the power of the current method to compare the fish oxygen-binding protein expression and its putative gene expansion event.Oxygen-binding proteins, such as myoglobin, hemoglobin, neuroglobin, and cytoglobin, play a role in oxygen binding and delivery to tissues. In icefish, the loss of myoglobin and hemoglobin genes has been reported to be an adaptive evolution event. This interesting finding prompted us to exam oxygen-binding protein expression in diverse fish species. Taking advantage of substantial RNAseq data deposited in the NCBI (National Center for Biotechnology Information) database, we adopted a meta-transcriptomic approach to explore and compare four oxygen-binding protein gene expression levels in the skeletal muscle of 25 diverse fish species for the first time. RNAseq data were downloaded from the NCBI Sequence Read Archive (SRA) database, and de novo assembly was performed to generate transcript contigs. The genes encoding oxygen-binding proteins were then identified by the BLAST search, and the relative expression level of oxygen-binding protein genes was normalized by the RPKM (Reads per Kilobase Million) method. By performing expression profiling, hierarchy clustering, and principal component analysis, pacu and loach fish were noticed by their high myoglobin expression levels in skeletal muscle tissues among 25 diverse fish species. In conclusion, we demonstrated that meta-transcriptomic analysis of RNAseq data is an informative approach to compare the oxygen-binding protein expression and putative gene expansion event in fish.
Highlights
Oxygen homeostasis is an essential mechanism in living organisms that is regulated by four major oxygen-binding proteins, namely hemoglobin, myoglobin, cytoglobin, and neuroglobin [1].The primary classification of these four oxygen-binding proteins is based on their tissue distribution and oxygen-binding affinity
The expression of hemoglobin and myoglobin genes is absent in some Antarctic icefishes [29,30]
This interesting phenomenon led us to ask whether the expression levels of oxygen-binding protein genes display a unique pattern among various fish species that live in a diverse habitat with different water oxygen levels
Summary
Oxygen homeostasis is an essential mechanism in living organisms that is regulated by four major oxygen-binding proteins, namely hemoglobin, myoglobin, cytoglobin, and neuroglobin [1].The primary classification of these four oxygen-binding proteins is based on their tissue distribution and oxygen-binding affinity. Oxygen homeostasis is an essential mechanism in living organisms that is regulated by four major oxygen-binding proteins, namely hemoglobin, myoglobin, cytoglobin, and neuroglobin [1]. The major role of these oxygen-binding proteins is on mediating oxygen-binding for storage and consumption, to reduce energy by respiratory progress. Myoglobin is a monomer and predominantly expressed in skeletal and cardiac muscles, and it is an essential intermediary factor to mediate an oxygen delivery from blood to muscle tissues [5,6]. Cytoglobin is a hemoprotein expressed in response to oxidative stress in a variety of tissues. It facilitates the diffusion of oxygen through tissues and helps intracellular oxygen transport [7,8]. The neuroglobin is a monomeric globin with a higher oxygen affinity than hemoglobin
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
