Comparison of Myosepta Development and Transcriptome Profiling between Blunt Snout Bream with and Tilapia without Intermuscular Bones

Abstract

Intermuscular bones (IBs) are small spicule-like bones located in the myosepta of basal teleosts, which negatively affect the edibleness and economic value of fish. Blunt snout bream (Megalobrama amblycephala, with epineural and epipleural IBs) and tilapia (Oreochromis niloticus, without epineural and epipleural IBs) are two major aquaculture species and ideal models for studying the formation mechanisms of fish IBs. Here, we compared myosepta development between M. amblycephala and O. niloticus, based on histological analysis, transcriptome profiling, and expression analysis of bone-related genes. The histological results showed that dye condensation began to appear in the myosepta 20 days post hatching (dph) in M. amblycephala, and IBs could be clearly observed 50 dph in the myosepta, based on different staining methods. However, in O. niloticus, dye condensation was not observed in the myosepta from 10 to 60 dph. Differentially expressed genes (DEGs) at different developmental stages were screened by comparing the transcriptomes of M. amblycephala and O. niloticus, and KEGG analysis demonstrated that these DEGs were enriched in many bone-related pathways, such as focal adhesion, calcium, and Wnt signaling pathways. Quantitative PCR was performed to further compare the expression levels of some bone-related genes (scxa, scxb, runx2a, runx2b, bgp, sp7, col1a2, entpd5a, entpd5b, phex, alpl, and fgf23). All the tested genes (except for alpl) exhibited higher expression levels in M. amblycephala than in O. niloticus. A comparison of the dorsal and abdominal muscle tissues between the two species also revealed significant expression differences for most of the tested genes. The results suggest that scxa, scxb, runx2a, runx2b, entpd5a, col1a2, and bgp may play important roles in IB development. Our findings provide some insights into the molecular mechanisms of IB formation, as well as clues for further functional analysis of the identified genes to better understand the development of IBs.

Fish Size Correlates to Size and Morphology of Intermuscular Bones in Tambaqui Colossoma macropomum as Shown by Dissection and X-ray Imaging Methods

“…After the findings of natural specimens of tambaqui lacking intermuscular bones [27], research has revealed the genes associated with the absence of intermuscular bones [30]; as such, the genetic and molecular mechanisms underlying the expression of such desirable phenotypes are currently better known [34]. Current genome-editing techniques, such as CRISPR-Cas9 [35], can be developed to generate new IB-defected strains; however, methods such as X-ray imaging can be essential, complementary and integrative in deducing and describing the IB morphology [18,20,36]. Between these two methods, X-ray imaging to count and measure IBs is a rapid and non-invasive technique and has thus recently become a very convenient and popular approach for various fish species [26,27,37].…”

Growth factors in the treatment of Achilles tendon injury

“…TGF-β isoforms have other effects during wound healing and scarring. While TGF-β3 is a significant inducer of Scx, which is expressed early in tendon development initiating tendon differentiation, it is also an inhibitor of collagen fiber maturation during tenogenic differentiation, especially in the late stage ( Perucca Orfei et al, 2019 ; Zhou et al, 2021a ). TGF-β3 alone or combined with other GFs acts as an essential tenogenic inducer in many cell types, such as AD-MSCs ( Shojaee et al, 2022 ), human tenocytes ( Tsiapalis et al, 2021 ), BMSCs ( Bottagisio et al, 2017 ), embryo-derived stem cells (ESCs) ( Barsby et al, 2014 ), tonsil-derived MSCs (TMSCs) ( Wee et al, 2022 ).…”

Transcriptome and Genome Analyses Applied to Aquaculture Research

“…Comparing species with and without epineural and epipleural IBs or fish strains with different abundances of them could provide interesting clues for reducing the number of IBs. Zhou et al [ 26 ] analyzed different stages of myosepta development using morphological and transcriptomics analyses in blunt snout bream ( Megalobrama amblycephala ) and Nile tilapia ( Oreochromis niloticus ), fish species with and without epineural and epipleural IBs, respectively. Among other results, the authors identified a repertoire of genes that may play important roles in IB development, with could provide interesting information for further studies [ 26 ].…”

“…Zhou et al [ 26 ] analyzed different stages of myosepta development using morphological and transcriptomics analyses in blunt snout bream ( Megalobrama amblycephala ) and Nile tilapia ( Oreochromis niloticus ), fish species with and without epineural and epipleural IBs, respectively. Among other results, the authors identified a repertoire of genes that may play important roles in IB development, with could provide interesting information for further studies [ 26 ]. On the other hand, Cui et al [ 27 ] conducted whole-genome resequencing and bulked segregant analysis in three common carp strains with a different abundance of IBs to identify SNPs that could be associated with the number of IBs.…”