Differential expression of proteins and phosphoproteins during larval metamorphosis of the polychaete Capitella sp. I

Abstract

BackgroundThe spontaneous metamorphosis of the polychaete Capitella sp. I larvae into juveniles requires minor morphological changes, including segment formation, body elongation, and loss of cilia. In this study, we investigated changes in the expression patterns of both proteins and phosphoproteins during the transition from larvae to juveniles in this species. We used two-dimensional gel electrophoresis (2-DE) followed by multiplex fluorescent staining and MALDI-TOF mass spectrometry analysis to identify the differentially expressed proteins as well as the protein and phosphoprotein profiles of both competent larvae and juveniles.ResultsTwenty-three differentially expressed proteins were identified in the two developmental stages. Expression patterns of two of those proteins were examined at the protein level by Western blot analysis while seven were further studied at the mRNA level by real-time PCR. Results showed that proteins related to cell division, cell migration, energy storage and oxidative stress were plentifully expressed in the competent larvae; in contrast, proteins involved in oxidative metabolism and transcriptional regulation were abundantly expressed in the juveniles.ConclusionIt is likely that these differentially expressed proteins are involved in regulating the larval metamorphosis process and can be used as protein markers for studying molecular mechanisms associated with larval metamorphosis in polychaetes.

HSP90 regulates larval settlement of the bryozoan Bugula neritina through NO pathway

“…As one of the functions of NO is preventing cells from going through apoptosis, Leise et al (2004) found that the low level of expression of NOS triggered apical ganglion loss during metamorphosis, suggesting the necessity of reduced NOS expression to initiate nervous system breakdown. In terms of HSP90, the decreased expression level after attachment in comparison with swimming larvae is consistent with previous studies in the polychaete Capitella, which also shows the highest expression level of HSP90 in competent pelagic larvae, and a decreased expression level upon settlement (Chandramouli et al, 2011). Like B. neritina, this species has a biphasic life cycle, during which it undergoes metamorphosis into a benthic juvenile.…”

“…Like B. neritina, this species has a biphasic life cycle, during which it undergoes metamorphosis into a benthic juvenile. Chandramouli et al (2011) argued that non-feeding larvae might experience the destruction of the larval structures as well as constant substratum exploration, and that these factors could lead to oxidative stress, causing higher expression levels of HSP90 in the larval stage. This elevated HSP90 expression may act as a coping mechanism for non-feeding larvae under stressful conditions.…”

Proteomic Changes Associated with Successive Reproductive Periods in Male Polychaetous Neanthes arenaceodentata

“…Larger worms are generally more successful in fighting and pairing with other worms 18 . Several elastic or cytoskeletal proteins associated with body musculature, mechanical support and cellular signaling are present in polychaetes 19 20 21 . During the incubation period, the body of the male undulates to renew water 10 , and males fight off other individuals of both sexes to protect their embryos 1 .…”

Proteomic Changes between Male and Female Worms of the Polychaetous Annelid Neanthes arenaceodentata before and after Spawning

“…We believe that prior to spawning immature MM and MF exhibit common morphological features that are associated with the same set of proteome. In previous study [9], we proposed that 2-DE proteome analysis of whole worms increases sample complexity and thus prevents identification of low abundant proteins [34,35]. In addition, 2-DE proteomics generates proteome profiles that only represent highly abundant proteins [36,37].…”