Characterization and Expression Analysis of Mollusk-like Growth Factor: A Secreted Protein Involved in Pacific Abalone Embryonic and Larval Development

Abstract

Growth factors are mostly secreted proteins that play key roles in an organism’s biophysical processes through binding to specific receptors on the cell surface. The mollusk-like growth factor (MLGF) is a novel cell signaling protein in the adenosine deaminase-related growth factor (ADGF) subfamily. In this study, the MLGF gene was cloned and characterized from the digestive gland tissue of Pacific abalone and designated as Hdh-MLGF. The transcribed full-length sequence of Hdh-MLGF was 1829 bp long with a 1566 bp open reading frame (ORF) encoding 521 amino acids. The deduced amino acid sequence contained a putative signal peptide and two conserved adenosine deaminase domains responsible for regulating molecular function. Fluorescence in situ hybridization localized Hdh-MLGF in the submucosa layer of digestive tubules in the digestive gland. The mRNA expression analysis indicated that Hdh-MLGF expression was restricted to the digestive gland in the adult Pacific abalone. However, Hdh-MLGF mRNA expressions were observed in all stages of embryonic and larval development, suggesting Hdh-MLGF might be involved in the Pacific abalone embryonic and larval development. This is the first study describing Hdh-MLGF and its involvement in the Pacific abalone embryonic and larval development.

The Neuropeptide HGAP Regulates Growth, Reproduction, Metamorphosis, Tissue Damage Repair, and Response against Starvation in Pacific Abalone

“…Therefore, it is plausible that Hdh-HGAP may have direct or indirect involvement in these developmental events. In fact, previous studies have reported the involvement of secreted growth-related genes in the metamorphosis of Pacific abalone [ 22 ].…”

“…Three-year-old reproductively mature 12 females’ and 4 male’s abalone were induced for artificial fertilization. After spawning, unfertilized eggs (UFE) and sperm were collected, and artificial fertilization was performed following the procedure described by Hanif et al [ 22 ]. After fertilization, samples of target stages, including fertilized eggs (FE), 2-cell (2-CL) and 4-cell (4-CL) stages, morula (MOR), trochophore (TRP) larvae, veliger (VLG) larvae, and juveniles (JUV), were collected through microscopic observation.…”

Molecular Characterization of Tropomyosin and Its Potential Involvement in Muscle Contraction in Pacific Abalone

“…Artificial fertilization of Pacific abalones was performed following the procedure described by Hanif et al [29]. Briefly, male abalones with fully mature gonad were induced to release sperm by sunlight exposure (60 min shell-side down and 40 min shell-side down).…”

“…The expression levels of Hdh-TPM were observed in the different organs of adult Pacific abalone and the various embryonic and larval developmental stages of Pacific abalone. All qRT-PCRs were conducted following the protocol previously described by Hanif et al [29]. In qRT-PCR analysis, three biological replicates were used in this study.…”

pathway is crucial for larval survival and shell development in Pacific abalone (Haliotis discus hannai)

“…As mollusks, Haliotis discus hannai is one of the most important economic species in shellfish culture in China. It is an urgent and arduous task to explore the mechanism of larval development and put forward the management measures which can guide production practice [ 11 ]. It is clear that the Hippo pathway plays an important role in the larval development of mollusks, but there has been little report so far.…”