Regulatory effects of soy isoflavones on ovarian development in female Chinese mitten crabs (Eriocheir sinensis).

Optimizing gonadal development and muscle flavor quality in the male Chinese mitten crabs (Eriocheir sinensis): Utilization of soy isoflavones in crustaceans

Effects of fattening period on ovarian development and nutritional quality of adult female Chinese mitten crab Eriocheir sinensis

The freshwater Chinese mitten crab (Eriocheir sinensis), an indigenous crustacean in China, has been cultured for more than 30 years. It was reported that the bunya-like virus from Eriocheir sinensis (EsBV) was associated with the tremor disease (TD), which causes high mortality and has a serious impact on production. In this study, full-length genome sequences of EsBV were pursued using next generation sequencing; the genome of EsBV was found to be composed of 6.7kb L, 3.3kb M, and 0.8kb S segments, respectively. PCR detection based genomic sequences showed that the positive rate of EsBV reached 40% in crabs from farming ponds. EsBV had the highest similarity with the Wenling crustacean virus 9, an unassigned, negative sense ssRNA virus. EsBV clustered with the Wenling crustacean virus 9 firstly, and then the branch clustered with Peribunyaviridae clade in every phylogenetic tree - based on L, M and S encoded sequences, respectively, indicating that EsBV can be classified in the family Peribunyaviridae, to which the orthobunyaviruses belongs, but not belonging to any known genera in the family Peribunyaviridae. There were unique complimentary terminal sequences for EsBV, with only partial consensus with members from the orthobunyaviruses. We believe that the findings of this research will be vital for future research about EsBV and will also go a long way in illuminating its relationship with TD. Keywords: Eriocheir sinensis; tremor disease; bunyavirus; EsBV; genome sequences.

Chinese mitten crab Eriocheir sinensis is a very important aquaculture species in China. Because of high edible yield ,delicate flavour, excellent nutritional quality and rapid growth, the crab has been widely cultured and stocked in ponds, reservoirs and lakes after 1990’s. As a consequence, the aquaculture production of this species had increased from 8,000 tons in 1991 to approximately 500, 000 tons in 2004. Female E. sinensis is known to be able to spawn more than one batch of eggs after a single mating, which will take approximately one or two month to develop their ovaries for the second spawning after the first spawning. There are some differences between the first ovarian development and the second ovarian development of E. sinensis, i . e. the first ovarian development always lasts 324 months, while the second ovarian development only takes 122 months. Although there are many researches conducted to investigate the first ovarian development , only one available literature could be found on the second ovarian development of E. sinensis. So, the present study aimed to investigate the changes of the gonadosomatic index (GSI), hepatosomatic index (HSI), external features of ovary, main biochemical composition in ovaries and hepatopancreas during the second ovarian development of E. sinensis, which should provide valuable information for comprehending the reproductive biology and optimizing broodstock breeding on female E. sinensis .During March to May in 2005, the mature female E. sinensis were held in the indoor captive conditions and fed with fresh clam, Sinonovacula constricta. After the mating, the spawned females were sampled and dissected to investigate the changes of the GSI, HSI, external features of ovary. Furthermore, the main biochemical composition in ovaries and hepatopancreas were determined during the second ovarian development of E. sinensis. The results showed that : 1. During the second ovarian development of E. sinensis, the GSI increased significantly from 0. 82 % in stage Ⅰto 5.42 % in stage Ⅳ, which was significantly lower than the GSI in stage Ⅳ (GSI 10 % -14 %) during the first ovarian development. The ovary developed slowly during the berried period of female E. sinensis , which could be explained that the more energy was consumed by agitating their abdomens for embryonic development. 2. However, the HSI rose slightly, then declined gradually during the period. The positive correlation could be found between GSI and days after spawning (DAS) and the negative correlation could be observed between GSI and HSI during the second ovarian development. 3. The moisture in ovary decreased significantly, while the lipid, protein and carbohydrate content increased significantly. However the moisture in hepatopancreas increased significantly, the lipid and carbohydrate content decreased dramatically. 4. The correlative analysis showed that there were significantly positive correlations between the lipid, protein, carbohydrate content and GSI, and the negative correlation was found between GSI and moisture in ovary. The similar trend was also found between those biochemical compositions in hepatopancreas and HSI except for protein level in hepatopancreas, which was constant (10 % -12 %of wet weight) during the second ovarian development. The lipid content in hepatopancreas and ovary was negative correlation during the period , which indicated that the hepatic lipid was transported to ovaryduring the second ovarian development of E. sinensis.  

This editorial summarizes the recent American Heart Association (AHA) Science Advisory on soy protein and isoflavones (phytoestrogens) published in the February 21, 2006, issue of Circulation .1 Soy protein and isoflavones have gained considerable attention for their potential role in improving risk factors for cardiovascular disease. This scientific advisory report assesses the more recent work published on soy protein and its component isoflavones. In 22 randomized trials, isolated soy protein with isoflavones compared with milk or other proteins decreased LDL cholesterol concentrations in most studies; the average effect was approximately 3%. This reduction is very small compared with the large amount of soy protein tested in these studies, averaging 50 g, approximately half the usual total daily protein intake. No significant effects were evident on HDL cholesterol, triglycerides, lipoprotein(a), or blood pressure. Among 19 studies of soy isoflavones, the average effect on LDL cholesterol and other lipid risk factors was nil. Soy protein or isoflavones have not been shown to lessen vasomotor symptoms of menopause, and results are mixed regarding slowing of postmenopausal bone loss. The efficacy and safety of soy isoflavones for preventing or treating cancer of the breast, endometrium, and prostate are not established; evidence from clinical trials is meager and cautionary as regards a possible adverse effect. For this reason, use of isoflavone supplements in food or pills is not recommended. Thus, earlier research indicating that soy protein compared with other proteins has clinically important favorable effects has not enjoyed confirmation. In contrast, many soy products should be beneficial to cardiovascular and overall health because of their high content of polyunsaturated fats, fiber, vitamins, and minerals and low content of saturated fat. In October 1999, the US Food and Drug Administration (FDA) approved labeling for foods containing soy protein as protective against coronary heart disease.2 …

Identification and expression analysis of lipopolysaccharide-induced TNF-alpha factor gene in Chinese mitten crab Eriocheir sinensis

ABSTRACTRecent advances in viromics have led to the discovery of a great diversity of RNA viruses and the identification of a large number of viral pathogens. A systematic exploration of viruses in Chinese mitten crab (Eriocheir sinensis), one of the most important aquatic commercial species, is still lacking. Here, we characterized the RNA viromes of asymptomatic, milky disease (MD)-affected, and hepatopancreatic necrosis syndrome (HPNS)-affected Chinese mitten crabs collected from 3 regions in China. In total, we identified 31 RNA viruses belonging to 11 orders, 22 of which were first reported here. By comparing viral composition between samples, we observed high variation in viral communities across regions, with most of the viral species being region-specific. We proposed to establish several novel viral families or genera based on the phylogenetic relationships and genome structures of viruses discovered in this study, expanding our knowledge of viral diversity in brachyuran crustaceans.IMPORTANCE High-throughput sequencing and meta-transcriptomic analysis provide us with an efficient tool to discover unknown viruses and explore the composition of viral communities in specific species. In this study, we investigated viromes in asymptomatic and diseased Chinese mitten crabs collected from three distant locations. We observed high regional variation in the composition of viral species, highlighting the importance of multi-location sampling. In addition, we classified several novel and ICTV-unclassified viruses based on their genome structures and phylogenetic relationships, providing a new perspective on current viral taxa.

Identification and characterization of the cDNAs encoding the two subunits of Chinese mitten crab (Eriocheir sinensis) calcineurin: Their implications in stress and immune response

Characterization of the vasa gene in the Chinese mitten crab Eriocheir sinensis: A germ line molecular marker

Expression pattern of AGPATs isoforms indicate different functions during the triacylglyceride synthesis in Chinese mitten crab, Eriocheir sinensis

Effects of water temperature on growth, feeding and molting of juvenile Chinese mitten crab Eriocheir sinensis

Characterization of two C-type lectin-like domain (CTLD)-containing proteins from the cDNA library of Chinese mitten crab Eriocheir sinensis

Phagostimulant MTSG supplementation benefits growth-promoting and defensive effects of Rhodobacter azotoformans on Chinese mitten crab Eriocheir sinensis

Shewanella putrefaciens has been recognized as an emerging important pathogen in aquaculture. However, scarce information is available on the characterization and microbial control of S. putrefaciens as a causal agent of hepatopancreas necrosis disease in Chinese mitten crab Eriocheir sinensis. In this study, a multi-resistant S. putrefaciens isolate (DZ-A) was identified as a causal pathogen of hepatopancreas necrosis disease in Chinese mitten crabs. It showed a lethal dose (LD50) of 2.20 × 105 CFU ml-1 in Chinese mitten crabs, and multiple resistance to aminoglycoside, chloramphenicol, macrolide, penicillin, peptide, and tetracycline antimicrobials. In addition, Bdellovibrio powder exhibited a significant antibacterial effect against the pathogenic S. putrefaciens, and conferred significant protection to challenged Chinese mitten crabs with relative percentage survivals of 80.00% to 93.33% via significant improvement in their immune response and antioxidant capability. The findings of this study provide valuable insights into the phenotypic characterization and biological control of pathogenic S. putrefaciens in Chinese mitten crabs.

Arachidonic acid promotes ovarian development by modulating lipid metabolism and steroid hormone secretion in Chinese mitten crab (Eriocheir sinensis)