Intensity of larval diapause in the bamboo borer, Omphisa fuscidentalis

Larvae of the bamboo borer, Omphisa fuscidentalis, enter larval diapause in September and pupate in the following June (Singtripop et al., 1999). We examined the changes in the responses of larvae to exogenous 20-hydroxyecdysone (20E) in order to estimate the progress of diapause development. In this respect, we adopted two terms, responsiveness and sensitivity of larvae to 20E. Responsiveness was estimated by the percentage of larvae that pupated, and sensitivity was evaluated by the duration from the day of 20E injection to pupation. The responsiveness of larvae declined gradually from September to November when larvae were least responsive to 20E, and then increased markedly from January to February. This indicates that the intensity of diapause increases from September to November and terminated gradually thereafter. Thus the sequence of events as the larval responses to 20E is characterized by a V-shaped curve. Sensitivity of larvae to 20E was at the same level from September to December, and increased remarkably from December to January. The abrupt increase in the sensitivity occurred one month earlier than the bottom of the V-shaped curve of larval responsiveness, suggesting that the increases in the responsiveness and sensitivity in the latter hall of diapause may be brought about by respective mechanisms

Deciphering Proteomic Signatures of Early Diapause in Nasonia

Insect diapause is an alternative life-history strategy used to increase longevity and survival in harsh environmental conditions. Even though some aspects of diapause are well investigated, broader scale studies that elucidate the global metabolic adjustments required for this remarkable trait, are rare. In order to better understand the metabolic changes during early insect diapause, we used a shotgun proteomics approach on early diapausing and non-diapausing larvae of the recently sequenced hymenopteran model organism Nasonia vitripennis. Our results deliver insights into the molecular underpinnings of diapause in Nasonia and corroborate previously reported diapause-associated features for invertebrates, such as a diapause-dependent abundance change for heat shock and storage proteins. Furthermore, we observed a diapause-dependent switch in enzymes involved in glycerol synthesis and a vastly changed capacity for protein synthesis and degradation. The abundance of structural proteins and proteins involved in protein synthesis decreased with increasing diapause duration, while the abundance of proteins likely involved in diapause maintenance (e.g. ferritins) increased. Only few potentially diapause-specific proteins were identified suggesting that diapause in Nasonia relies to a large extent on a modulation of pre-existing pathways. Studying a diapause syndrome on a proteomic level rather than isolated pathways or physiological networks, has proven to be an efficient and successful avenue to understand molecular mechanisms involved in diapause

First Transcriptome of the Testis-Vas Deferens-Male Accessory Gland and Proteome of the Spermatophore from Dermacentor variabilis (Acari: Ixodidae)

Ticks are important vectors of numerous human diseases and animal diseases. Feeding stimulates spermatogenesis, mating and insemination of male factors that trigger female reproduction. The physiology of male reproduction and its regulation of female development are essentially a black box. Several transcriptomes have catalogued expression of tick genes in the salivary glands, synganglion and midgut but no comprehensive investigation has addressed male reproduction and mating. Consequently, a new global approach using transcriptomics, proteomics, and quantitative gene expression is needed to understand male reproduction and stimulation of female reproduction