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Yang Z, Zhang L, Zhang W, Tian X, Lai W, Lin D, Feng Y, Jiang W, Zhang Z, Zhang Z. Identification of the principal neuropeptide MIP and its action pathway in larval settlement of the echiuran worm Urechis unicinctus. BMC Genomics 2024; 25:337. [PMID: 38641568 PMCID: PMC11027379 DOI: 10.1186/s12864-024-10228-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 03/15/2024] [Indexed: 04/21/2024] Open
Abstract
BACKGROUND Larval settlement and metamorphosis represent critical events in the life history of marine benthic animals. Myoinhibitory peptide (MIP) plays a pivotal role in larval settlement of marine invertebrates. However, the molecular mechanisms of MIP involved in this process are not well understood. RESULTS In this study, we evaluated the effects of thirteen MIP mature peptides on triggering the larval settlement of Urechis unicinctus (Xenopneusta, Urechidae), and determined that MIP2 was the principal neuropeptide. Transcriptomic analysis was employed to identify differentially expressed genes (DEGs) between the MIP2-treated larvae and normal early-segmentation larvae. Both cAMP and calcium signaling pathways were enriched in the DEGs of the MIP2-treated larvae, and two neuropeptide receptor genes (Spr, Fmrfar) were up-regulated in the MIP2-treated larvae. The activation of the SPR-cAMP pathway by MIP2 was experimentally validated in HEK293T cells. Furthermore, fourteen cilia-related genes, including Tctex1d2, Cfap45, Ift43, Ift74, Ift22, Cav1 and Mns1, etc. exhibited down-regulated expression in the MIP2-treated larvae. Whole-mount in situ hybridization identified two selected ciliary genes, Tctex1d2 and Cfap45, were specially expressed in circumoral ciliary cells of the early-segmentation larvae. Knocking down Tctex1d2 mRNA levels by in vivo RNA interference significantly increased the larval settlement rate. CONCLUSION Our findings suggest that MIP2 inhibits the function of the cilia-related genes, such as Tctex1d2, through the SPR-cAMP-PKA pathway, thereby inducing larval settlement in U. unicinctus. The study contributes important data to the understanding of neuropeptide regulation in larval settlement.
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Affiliation(s)
- Zhi Yang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Long Zhang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Wenqing Zhang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Xinhua Tian
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Wenyuan Lai
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Dawei Lin
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Yuxin Feng
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Wenwen Jiang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Zhengrui Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
| | - Zhifeng Zhang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China.
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
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Kong D, Wei M, Liu D, Zhang Z, Ma Y, Zhang Z. Morphological Observation and Transcriptome Analysis of Ciliogenesis in Urechis unicinctus (Annelida, Echiura). Int J Mol Sci 2023; 24:11537. [PMID: 37511295 PMCID: PMC10380512 DOI: 10.3390/ijms241411537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 07/13/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
During the early development of marine invertebrates, planktic larvae usually occur, and their body surfaces often form specific types of cilia that are involved in locomotion and feeding. The echiuran worm Urechis unicinctus sequentially undergoes the formation and disappearance of different types of body surface cilia during embryonic and larval development. The morphological characteristics and molecular mechanisms involved in the process remain unclear. In this study, we found that body surface cilia in U. unicinctus embryos and larvae can be distinguished into four types: body surface short cilia, apical tufts, circumoral cilia and telotrochs. Further, distribution and genesis of the body surface cilia were characterized using light microscope and electron microscope. To better understand the molecular mechanism during ciliogenesis, we revealed the embryonic and larval transcriptome profile of the key stages of ciliogenesis in U. unicinctus using RNA-Seq technology. A total of 29,158 differentially expressed genes (DEGs) were obtained from 24 cDNA libraries by RNA-Seq. KEGG pathway enrichment results showed that Notch, Wnt and Ca2+ signaling pathways were significantly enriched during the occurrence of apical tufts and circumoral cilia. Furthermore, all DEGs were classified according to their expression pattern, and DEGs with similar expression pattern were grouped into a module. All DEG co-expression modules were correlated with traits (body surface short cilia, apical tufts, circumoral cilia and telotrochs) by WGCNA, the results showed DEGs were divided into 13 modules by gene expression patterns and that the genes in No. 7, No. 8 and No. 10 modules were to be highly correlated with the occurrence of apical tufts, circumoral cilia and telotrochs. The top 10 hub genes in the above three modules were identified to be highly correlated with ciliogenesis, including the reported cilium-related gene Cnbd2 and unreported cilium-related candidate genes FAM181B, Capsl, Chst3, TMIE and Innexin. Notably, Innexin was included in the top10 hub genes of the two modules (No. 7 and No. 8), suggesting that Innexin may play an important role in U. unicinctus apical tufts, circumoral cilia and telotrochs genesis. This study revealed the characteristics of ciliogenesis on the body surface of U. unicinctus embryos and larvae, providing basic data for exploring the molecular mechanism of ciliogenesis on the body surface.
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Affiliation(s)
- Dexu Kong
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Maokai Wei
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Danwen Liu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Zhengrui Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yubin Ma
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Zhifeng Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya 572000, China
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Wang Y, Liu D, Wei M, Chen J, Li Y, Zhao F, Zhang Z, Ma Y. Genome-wide identification and expression analyses of Toll-like receptors provide new insights on adaptation to intertidal benthic environments in Urechis unicinctus (Annelida, Echiura). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 260:106594. [PMID: 37263159 DOI: 10.1016/j.aquatox.2023.106594] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 05/26/2023] [Accepted: 05/27/2023] [Indexed: 06/03/2023]
Abstract
Toll-like receptors (TLR) are an important class of pattern recognition receptors involved in innate immunity that recognize pathogen-associated and damage-associated molecular patterns. Although the role of TLRs in immunity has been extensively studied, a systematic investigation of their function in environmental adaptation is still in its infancy. In this study, a genome-wide search was conducted to systematically investigate TLR family members of Urechis unicinctus, a typical benthic organism in intertidal mudflats. A total of 28 TLR genes were identified in the U. unicinctus genome, and their fundamental physiological and biochemical properties were characterized. Gene copy number analysis among species in different habitats indicated that TLR family gene expansion may be probably related with benthic environmental adaptation. To further investigate the expression patterns of TLR members under environmental stress, transcriptome data was analyzed from different developmental stages and the hindgut under sulfide stress. Transcriptome analysis of different developmental stages showed that most TLR genes were highly expressed during a key period of benthic environment adaptation (worm-shaped larva). Transcriptome analysis of the hindgut under sulfide stress showed that the expression of 12 TLR members was significantly induced under sulfide stress. These results indicate that the regulation of TLR gene expression may be probably involved in the adaptation of U. unicinctus to the benthic intertidal zone environment. Taken together, this study may lay the foundation for future functional analysis of the specific role of TLRs in host immune responses against sulfide exposure and benthic environmental stress in annelid.
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Affiliation(s)
- Yunjian Wang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Danwen Liu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Maokai Wei
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Jiao Chen
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yunpeng Li
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572000, China
| | - Feng Zhao
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Zhifeng Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572000, China
| | - Yubin Ma
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
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Chen J, Wang Y, Yang Z, Liu D, Jin Y, Li X, Deng Y, Wang B, Zhang Z, Ma Y. Identification and validation of the reference genes in the echiuran worm Urechis unicinctus based on transcriptome data. BMC Genomics 2023; 24:248. [PMID: 37165306 PMCID: PMC10170059 DOI: 10.1186/s12864-023-09358-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/05/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Real-time quantitative PCR (RT-qPCR) is a crucial and widely used method for gene expression analysis. Selecting suitable reference genes is extremely important for the accuracy of RT-qPCR results. Commonly used reference genes are not always stable in various organisms or under different environmental conditions. With the increasing application of high-throughput sequencing, transcriptome analysis has become an effective method for identifying novel stable reference genes. RESULTS In this study, we identified candidate reference genes based on transcriptome data covering embryos and larvae of early development, normal adult tissues, and the hindgut under sulfide stress using the coefficient of variation (CV) method in the echiuran Urechis unicinctus, resulting in 6834 (15.82%), 7110 (16.85%) and 13880 (35.87%) candidate reference genes, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that the candidate reference genes were significantly enriched in cellular metabolic process, protein metabolic process and ribosome in early development and normal adult tissues as well as in cellular localization and endocytosis in the hindgut under sulfide stress. Subsequently, ten genes including five new candidate reference genes and five commonly used reference genes, were validated by RT-qPCR. The expression stability of the ten genes was analyzed using four methods (geNorm, NormFinder, BestKeeper, and ∆Ct). The comprehensive results indicated that the new candidate reference genes were more stable than most commonly used reference genes. The commonly used ACTB was the most unstable gene. The candidate reference genes STX12, EHMT1, and LYAG were the most stable genes in early development, normal adult tissues, and hindgut under sulfide stress, respectively. The log2(TPM) of the transcriptome data was significantly negatively correlated with the Ct values of RT-qPCR (Ct = - 0.5405 log2(TPM) + 34.51), which made it possible to estimate the Ct value before RT-qPCR using transcriptome data. CONCLUSION Our study is the first to select reference genes for RT-qPCR from transcriptome data in Echiura and provides important information for future gene expression studies in U. unicinctus.
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Affiliation(s)
- Jiao Chen
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yunjian Wang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Zhi Yang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya, China
| | - Danwen Liu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yao Jin
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xixi Li
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yuhang Deng
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Boya Wang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Zhifeng Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya, China
| | - Yubin Ma
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
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Temereva E, Rimskaya-Korsakova N. Nuchal organs in the trochophore of Siboglinum fiordicum (Annelida, Siboglinidae). JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2023. [PMID: 36859788 DOI: 10.1002/jez.b.23192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 01/25/2023] [Accepted: 02/16/2023] [Indexed: 03/03/2023]
Abstract
Nuchal organs are epidermal sensory structures present in most annelids. Based on one of the interpretations, they serve in larval settlement. Siboglinids lack nuchal organs in adult and larval stages, however, larvae of some siboglinids inhabiting seeps and hydrothermal vents are capable of swimming up to 100 km away from their home hydrothermal field to colonize a new one. One question that remains is, what organ are siboglinid larvae using to search and locate suitable substrates? To determine if any nuchal organs are present in siboglinid larvae, we studied the head and sensory apparatus in successive larval stages in a frenulate, Siboglinum fiordicum (Webb, 1963), using transmission electron microscopy and immunocytochemistry. In the early trochophore stage, we found an unpaired dorsal organ lying proximal to the posterior prototroch. This organ consists of trochoblast- and "covering" cells. Trochoblasts exhibited serotonin-like immunoreactivity and likely correspond to ciliated supporting cells, where cilia and microvilli project into the olfactory chamber. The "covering" cells are characterized by the presence of large nuclei with numerous pores and thick processes that project into the olfactory chamber, forming the contacts with the trochoblast projections. We have shown for the first time the presence of a nuchal-like organ in annelids as early as the trochophore stage. The presence of this organ in siboglinid trochophores while they are still in the inside the female tube suggests that this structure might be associated with functions other than settlement, such as communication or initiation of the departure from her tube.
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Affiliation(s)
- Elena Temereva
- Department of Invertebrate Zoology, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia.,Faculty of Biology and Biotechnology, National Research University Higher School of Economics, Moscow, Russia
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Li C, Zheng Y, Cong X, Liu H, Storey KB, Chen M. Molecular and functional characterization of the luqin-type neuropeptide signaling system in the sea cucumber Apostichopus japonicus. Peptides 2022; 155:170839. [PMID: 35839946 DOI: 10.1016/j.peptides.2022.170839] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/10/2022] [Accepted: 07/10/2022] [Indexed: 11/18/2022]
Abstract
The functional characteristics of neuropeptides in marine invertebrates have attracted significant attention recently although functional studies of luqin-type neuropeptides are still very limited, especially in deuterostomes. The sea cucumber, Apostichopus japonicus, is a representative species of deuterostomian Holothurian invertebrates. The species has high nutritional and medicinal value in China. In this study, we report the first comprehensive histological, biochemical and pharmacological characterization of luqin-type neuropeptide signaling in the sea cucumber A. japonicus. The A. japonicus luqin-like neuropeptide precursor (AjLQP) contains a single typical deuterostomian luqin-like neuropeptide AjLQ with an xFxRWamide motif. AjLQ was identified as the ligand for a luqin-type neuropeptide receptor AjLQR, that was previously predicted to be a tachykinin-type receptor, and triggers a rapid intracellular mobilization of Ca2+, followed by receptor internalization and a transient increase in ERK1/2 phosphorylation. In situ hybridization, immunohistochemistry and qRT-PCR analysis revealed extensive expression of AjLQP and AjLQ in A. japonicus tissues, especially in locomotion-related organs. In vitro pharmacological tests revealed that AjLQ caused 12.69% ± 1.99% (p < 0.01) relaxation of longitudinal muscle preparations at 10-7 M concentration. Furthermore, we observed significantly increased expression of AjLQP (about 17.63 fold, p < 0.01) in intestine of deeply aestivating sea cucumbers, which suggests that AjLQ might be involved in feeding inhibition during aestivation. The present study provides a first insight into the experimental characterization of luqin-type neuropeptide signaling in a sea cucumber. The results will broaden our understanding of the potential function of neuropeptides during important biological processes in marine invertebrates and provide theoretical support for optimizing sea cucumber aquaculture technology.
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Affiliation(s)
- Chenyi Li
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, PR China
| | - Yingqiu Zheng
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, PR China
| | - Xiao Cong
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, PR China
| | - Huachen Liu
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, PR China
| | - Kenneth B Storey
- Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada
| | - Muyan Chen
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, PR China.
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Bai S, Fan S, Liu D, Zhang Z, Zhang Z. Identification and expression analysis of receptors that mediate MIP regulating larval settlement in Urechis unicinctus. Comp Biochem Physiol B Biochem Mol Biol 2022; 260:110732. [PMID: 35278715 DOI: 10.1016/j.cbpb.2022.110732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 10/18/2022]
Abstract
Larval attachment and metamorphosis are important processes during the development of some marine invertebrates. Myoinhibitory peptides (MIPs), a class of small molecular neuropeptides, have been revealed to be involved in regulating the larval settlement. In this paper, we identified two types of MIP membrane receptors, G-protein coupled receptor SPR and MIP-gated ion channel receptors MGIC1 and MGIC2 based on sequence homology with other species in the transcriptome database of Echiuroidea Urechis unicinctus (Xenopneusta, Urechidae). The results of in situ hybridization showed that positive signals of these receptors were obviously located in the apex of the segmentation larvae, a critical stage of U. unicinctus larval settlement. Further, these receptors were determined on the membrane of HEK293 cells by immunohistochemistry. Also, we verified that U. unicinctus MIP can activate its SPR receptor based on the results of the significantly decreased cAMP concentration in HEK293 cells. Our data will provide scientific reference for elucidating mechanism of neuropeptide regulating the larval attachment and metamorphosis in marine invertebrates.
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Affiliation(s)
- Shumiao Bai
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Shutong Fan
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Danwen Liu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Zhengrui Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
| | - Zhifeng Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Laboratory of Tropical Marine Germplasm Resources and Breesing Engineering, Sanya Oceanographic Institution, Ocean University of China, Sanya 572000, China.
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Zieger E, Calcino AD, Robert NSM, Baranyi C, Wanninger A. Ecdysis-related neuropeptide expression and metamorphosis in a non-ecdysozoan bilaterian. Evolution 2021; 75:2237-2250. [PMID: 34268730 DOI: 10.1111/evo.14308] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/22/2021] [Accepted: 06/29/2021] [Indexed: 12/28/2022]
Abstract
Ecdysis-related neuropeptides (ERNs), including eclosion hormone, crustacean cardioactive peptide, myoinhibitory peptide, bursicon alpha, and bursicon beta regulate molting in insects and crustaceans. Recent evidence further revealed that ERNs likely play an ancestral role in invertebrate life cycle transitions, but their tempo-spatial expression patterns have not been investigated outside Arthropoda. Using RNA-seq and in situ hybridization, we show that ERNs are broadly expressed in the developing nervous system of a mollusk, the polyplacophoran Acanthochitona fascicularis. While some ERN-expressing neurons persist from larval to juvenile stages, others are only present during settlement and metamorphosis. These transient neurons belong to the "ampullary system," a polyplacophoran-specific larval sensory structure. Surprisingly, however, ERN expression is absent from the apical organ, another larval sensory structure that degenerates before settlement is completed in A. fascicularis. Our findings thus support a role of ERNs in A. fascicularis metamorphosis but contradict the common notion that the apical organ-like structures shared by various aquatic invertebrates (i.e., cnidarians, annelids, mollusks, echinoderms) are of general importance for this process.
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Affiliation(s)
- Elisabeth Zieger
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Vienna, Austria
| | - Andrew D Calcino
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Vienna, Austria
| | - Nicolas S M Robert
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna, Austria
| | - Christian Baranyi
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Vienna, Austria
| | - Andreas Wanninger
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Vienna, Austria
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Li X, Ma Y, Zuo Y, Liu Z, Wang Q, Ren D, He Y, Cong H, Wu L, Zhou H. The efficient enrichment of marine peptides from the protein hydrolysate of the marine worm Urechis unicinctus by using mesoporous materials MCM-41, SBA-15 and CMK-3. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:2405-2414. [PMID: 33997883 DOI: 10.1039/d1ay00616a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Peptides found in marine life have various specific activities due to their special growth environment, and there is increasing interest in the isolation and concentration of these biofunctional compounds. In this study, the protein hydrolysate of the marine worm Urechis unicinctus was prepared by enzymolysis and enriched by using mesoporous materials of silica MCM-41 and SBA-15 and carbon CMK-3. The differences in pore structures and elemental composition of these materials lead to differences in surface area and hydrophobicity. The adsorption capacities of peptides were 459.5 mg g-1, 431.3 mg g-1, and 626.3 mg g-1 for MCM-41, SBA-15 and CMK-3, respectively. Adsorption kinetics studies showed that the pseudo-second-order model fit the adsorption process better, where both external mass transfer and intraparticle diffusion affected the adsorption, while the Langmuir model better fit the adsorption of peptides on MCM-41 and SBA-15 and the Freundlich model was more suitable for CMK-3. Aqueous acetonitrile (ACN, 50/50, v/v) yielded the most extracted peptides. MALDI-TOF mass spectrometry of the extracted peptides showed that the three mesoporous materials, especially the CMK-3, gave good enrichment results. This study demonstrates the great potential of mesoporous materials in the enrichment of marine biofunctional peptides.
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Affiliation(s)
- Xinwei Li
- College of Food Science and Engineering, Dalian Ocean University, Dalian, Liaoning 116023, China.
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Nässel DR, Wu SF. Leucokinins: Multifunctional Neuropeptides and Hormones in Insects and Other Invertebrates. Int J Mol Sci 2021; 22:1531. [PMID: 33546414 PMCID: PMC7913504 DOI: 10.3390/ijms22041531] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 12/27/2022] Open
Abstract
Leucokinins (LKs) constitute a neuropeptide family first discovered in a cockroach and later identified in numerous insects and several other invertebrates. The LK receptors are only distantly related to other known receptors. Among insects, there are many examples of species where genes encoding LKs and their receptors are absent. Furthermore, genomics has revealed that LK signaling is lacking in several of the invertebrate phyla and in vertebrates. In insects, the number and complexity of LK-expressing neurons vary, from the simple pattern in the Drosophila larva where the entire CNS has 20 neurons of 3 main types, to cockroaches with about 250 neurons of many different types. Common to all studied insects is the presence or 1-3 pairs of LK-expressing neurosecretory cells in each abdominal neuromere of the ventral nerve cord, that, at least in some insects, regulate secretion in Malpighian tubules. This review summarizes the diverse functional roles of LK signaling in insects, as well as other arthropods and mollusks. These functions include regulation of ion and water homeostasis, feeding, sleep-metabolism interactions, state-dependent memory formation, as well as modulation of gustatory sensitivity and nociception. Other functions are implied by the neuronal distribution of LK, but remain to be investigated.
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Affiliation(s)
- Dick R. Nässel
- Department of Zoology, Stockholm University, S-10691 Stockholm, Sweden
| | - Shun-Fan Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China;
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