Wnt8a is one of the candidate genes that play essential roles in the elongation of the seahorse prehensile tail

Abstract

Seahorses are a hallmark of specialized morphological features due to their elongated prehensile tail. However, the underlying genomic grounds of seahorse tail development remain elusive. Herein, we evaluated the roles of essential genes from the Wnt gene family for the tail developmental process in the lined seahorse (Hippocampus erectus). Comparative genomic analysis revealed that the Wnt gene family is conserved in seahorses. The expression profiles and in situ hybridization suggested that Wnt5a, Wnt8a, and Wnt11 may participate in seahorse tail development. Like in other teleosts, Wnt5a and Wnt11 were found to regulate the development of the tail axial mesoderm and tail somitic mesoderm, respectively. However, a significantly extended expression period of Wnt8a during seahorse tail development was observed. Signaling pathway analysis further showed that Wnt8a up-regulated the expression of the tail axial mesoderm gene (Shh), while interaction analysis indicated that Wnt8a could promote the expression of Wnt11. In summary, our results indicate that the special extended expression period of Wnt8a might promote caudal tail axis formation, which contributes to the formation of the elongated tail of the seahorse.

Deciphering the origin of developmental stability: The role of intracellular expression variability in evolutionary conservation

“…The methodologies employed here is applicable to other species, phenotypes, and evolutionary scales, which may help clarify the role of embryogenesis in directing phenotypic evolution. In fact, two primary models have been proposed for the foundational elements that govern phenotypic evolution; one is the variability of the intracellular state resulting in the advent of new cell types (Arendt, 2008; Arendt et al, 2016), and the other is the variability of spatial expression pattern driving modular change in tissue composition (Raff, 1996; Raff & Sly, 2000; Zhang et al, 2021). These models will not only be evaluated through phylogenetic evolution analyses, which examine the pattern of evolutionary outcomes to date, but also via ontogenic analysis, measuring the stabilities.…”

Gene loss and co-option of toll-like receptors facilitate paternal immunological adaptation in the brood pouch of pregnant male seahorses

“…Eleven tissues (brain, gill, liver, intestine, kidney, gonad, muscle, skin, blood, and placenta and out layer of brood pouch) were surgically removed. According to the method of Zhang and Whittington ( 10 , 52 ), the reproductive stages of brood pouch were judged by the placenta morphology and the embedded embryos development stage. In this study, five different reproductive stages (including pre-pregnancy, early-pregnancy, mid-pregnancy, late-pregnancy, and post-pregnancy) were divided.…”

“…To characterize the immune ligand recognition of TLR18, TLR21, and TLR25 in lined seahorses, eight typical TLR ligands (including 30 mg/mL LPS, 50 mg/mL LTA, 10 mg/mL Pam2CSK4, 10 mg/mL Pam3CSK4, 50 mg/mL polyinosinic:polycytidylic acid (Poly ( I : C ) ) , 1 0 m g / m L p h o s p h o r o t h i o a t e -m o d i fi e d C p Goligodeoxynucleotides (CpG-ODNs), 0.2 mg/mL Flagellin, and 50 mg/mL PGN) were selected to conduct a challenge experiment in vitro. The challenge experiment was conducted using a lined seahorse embryonic cell line (Chinese patent: ZL 2017 1 1050527.5) established in our on-site laboratory (52). Briefly, the cells were maintained in 6-well cell culture plates containing 5 mL Dulbecco's modified eagle medium per well: Ham's nutrient mixture F-12 (1:1) medium (DMEM/F12) supplemented with fetal bovine serum (FBS, 20%) at 28°C and 5% CO 2 atmosphere.…”

Identification of CTNNB1 in the lined seahorse, Hippocampus erectus, and its function in innate immunity and cell proliferation

“…The putative sequences of proteins, nucleotides, and alignment of amino acid sequences of these two CTNNB genes were compared and analyzed using NCBI Blast (https://blast.ncbi.nlm.nih.gov/Blast.cgi) (Zhao et al, 2020), Bio Edit 7.0.9 (Jeon et al, 2014), and ClustalX 1.83 program (Thompson et al, 1997), respectively. Phylogenetic tree analyses were constructed with MEGA 7.0.26 (Zhang et al, 2021).…”