Periviscerokinins (PVKs) and pyrokinins (PKs) are neuropeptides known in several arthropod species. Sequence homology of these peptides with the molluscan small cardioactive peptides reveals that the occurrence of PVKs and PKs is not restricted to arthropods. Our study focuses on the biochemical and immunocytochemical identification of neuropeptides with sequence homology to PVKs and PKs in the central and peripheral nervous system of the earthworm Eisenia fetida. By means of affinity chromatography, nanoflow liquid chromatography, and high accuracy mass spectrometry, six peptides, SPFPR(L/I)amide, APFPR( L/I)amide, SPLPR( L/I)amide, SFVR( L/I)amide, AFVR( L/I)amide, and SPAFVR( L/I)amide, were identified in the central nervous system with the common-XR( L/I)amide C-terminal sequence. The exact anatomical position of 13 labeled XR( I/L)amide expressing neuron groups and numerous peptide-containing fibers were determined by means of immunocytochemistry and confocal laser scanning microscopy in whole-mount preparations of ventral nerve cord ganglia. The majority of the stained neurons were interneurons with processes joining the distinct fine-fibered polysegmental tracts in the central neuropil. Some stained fibers were seen running in each segmental nerve that innervated metanephridia and body wall. Distinct groups of neurosecretory cells characterized by small round soma and short processes were also identified. Based on immunoelectron microscopy six different types of labeled cells were described showing morphological heterogeneity of earthworm peptides containing elements. Our findings confirm that the sequence of the identified earthworm neuropeptides homologous to the insect PVKs and PKs suggesting that these peptides are phylogenetically conservative molecules and are expressed in sister-groups of animals such as annelids, mollusks, and insects. J. Comp. Neurol. 514:415-432, 2009. (c) 2009 Wiley-Liss, Inc.
"The unpurified antiserum recognizes peptides with the C-terminal sequence PRXamide and is known to react with periviscerokinins and with pyrokinins (Eckert et al., 2002). It has been used to specifically label these substances in a variety of insect species (D. melanogaster: Wegener et al., 2004; Nezara viridula: Predel et al., 2006; Manduca sexta: Neupert et al., 2009); Schistocerca gregaria: Herbert et al., 2010; Acyrthosiphon pisum: Kollmann et al., 2011a), in the chelicerate Ixodes ricinus (Neupert et al., 2005), and in the clitellate annelid Eisenia fetida (Herbert et al., 2009). "
"Annelids represent a diverse and species-rich phylum and have long been used in neuroendocrinological and behavioral studies
. Comparative genomic approaches
[19,20,40] and other studies identified multiple annelid pNPs and neuropeptides, including RFa
[48-50], excitatory peptide (EP)
[51-53], egg-laying hormone (ELH)
, L11 or elevenin
[39,58,59], gonadotropin releasing hormone (GnRH)
[60,61], insulin-related peptides
, neuropeptide Y (NPY)
[63,64] and myoinhibitory peptide (MIP)
. Despite these advances, a complete picture of annelid neuropeptide diversity is still missing. "
[Show abstract][Hide abstract] ABSTRACT: The marine annelid Platynereis dumerilii is emerging as a powerful lophotrochozoan experimental model for evolutionary developmental biology (evo-devo) and neurobiology. Recent studies revealed the presence of conserved neuropeptidergic signaling in Platynereis, including vasotocin/neurophysin, myoinhibitory peptide and opioid peptidergic systems. Despite these advances, comprehensive peptidome resources have yet to be reported.
The present work describes the neuropeptidome of Platynereis. We established a large transcriptome resource, consisting of stage-specific next-generation sequencing datasets and 77,419 expressed sequence tags. Using this information and a combination of bioinformatic searches and mass spectrometry analyses, we increased the known proneuropeptide (pNP) complement of Platynereis to 98. Based on sequence homology to metazoan pNPs, Platynereis pNPs were grouped into ancient eumetazoan, bilaterian, protostome, lophotrochozoan, and annelid families, and pNPs only found in Platynereis. Compared to the planarian Schmidtea mediterranea, the only other lophotrochozoan with a large-scale pNP resource, Platynereis has a remarkably full complement of conserved pNPs, with 53 pNPs belonging to ancient eumetazoan or bilaterian families. Our comprehensive search strategy, combined with analyses of sequence conservation, also allowed us to define several novel lophotrochozoan and annelid pNP families. The stage-specific transcriptome datasets also allowed us to map changes in pNP expression throughout the Platynereis life cycle.
The large repertoire of conserved pNPs in Platynereis highlights the usefulness of annelids in comparative neuroendocrinology. This work establishes a reference dataset for comparative peptidomics in lophotrochozoans and provides the basis for future studies of Platynereis peptidergic signaling.
"questions related to the earthworms' nervous , immune  , and endocrine systems  . Instead, the whole earthworm or some of its products has been analyzed in credible experimental research related to biological function in mammals that still require further refinement. "
[Show abstract][Hide abstract] ABSTRACT: Earthworms have provided ancient cultures with food and sources of medicinal cures. Ayurveda, traditional Chinese medicine (TCM), and practices in Japan, Vietnam, and Korea have focused first on earthworms as sources of food. Gradually fostering an approach to potential beneficial healing properties, there are renewed efforts through bioprospecting and evidence-based research to understand by means of rigorous investigations the mechanisms of action whether earthworms are used as food and/or as sources of potential medicinal products. Focusing on earthworms grew by serendipity from an extensive analysis of the earthworm's innate immune system. Their immune systems are replete with leukocytes and humoral products that exert credible health benefits. Their emerging functions with respect to evolution of innate immunity have long been superseded by their well-known ecological role in soil conservation. Earthworms as inexpensive, noncontroversial animal models (without ethical concerns) are not vectors of disease do not harbor parasites that threaten humans nor are they annoying pests. By recognizing their numerous ecological, environmental, and biomedical roles, substantiated by inexpensive and more comprehensive investigations, we will become more aware of their undiscovered beneficial properties.
Evidence-based Complementary and Alternative Medicine 07/2012; 2012(1):164152. DOI:10.1155/2012/164152 · 1.88 Impact Factor
Maria Basanta-Sanchez, Sally Temple, Suraiya A Ansari, Anna D'Amico, Paul F Agris
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