+Advanced Search

2020 Vol. 2, No. 1

Review
Delivery methods for CRISPR/Cas9 gene editing in crustaceans
Sen Xu, Thinh Phu Pham, Swatantra Neupane
2020, 2(1): 1-5. doi: 10.1007/s42995-019-00011-4
HTML PDF Springerlink
Abstract:
In this mini-review, we provide an up-to-date overview of the delivery methods that have been used for CRISPR/Cas9 genomic editing in crustacean species. With embryonic microinjection as the main workforce for delivering CRISPR/Cas9 reagents, biologists working with crustacean species have to tackle the technical challenges involved in microinjection. We use examples of three crustacean species (the branchiopod Daphnia, amphipod Parhyale hawaiensis, and decapod Exopalaemon carinicauda) to provide a technical guide for embryonic microinjection. Moreover, we outline two potentially useful new techniques for delivering CRISPR/Cas9 components into crustaceans, i.e., Receptor-Mediated Ovary Transduction of Cargo (ReMOT Control) and electroporation.
Receptor, signal transduction and evolution of sweet, umami and bitter taste
Zhongmei Ren, Zhenhui Liu
2020, 2(1): 6-15. doi: 10.1007/s42995-019-00010-5
HTML PDF Springerlink
Abstract:
Like olfaction, the sense of taste allows the detection and discrimination of chemicals in the environment. However, while olfaction is specialized in the detection of volatile chemicals, taste is restricted to the detection of contact-chemicals. Two families of mammalian taste receptors, T1R and T2R, involved in recognition of sweet, umami (the taste of monosodium glutamate) and bitter stimuli have been identified and characterized. Although much progress has been made in studies on the basic mechanisms of taste recognition and signal transduction in mammals, we are still far from a full understanding of different taste qualities. This review presents a current perspective on sweet, bitter and umami taste receptors and their signal transduction mechanism. We also discuss the evolution of taste and taste-related molecules.
Chemical diversity and biological function of indolediketopiperazines from marine-derived fungi
Jin Cao, Bin-Gui Wang
2020, 2(1): 31-40. doi: 10.1007/s42995-019-00023-0
HTML PDF Springerlink
Abstract:
Natural products from marine-derived fungi have attracted considerable attention in the recent two decades. Indolediketopiperazines are one of the most important classes of marine natural products, mainly discovered from the fungal genera Penicillium, Aspergillus and Eurotium. These compounds span a wide range of chemical structures and bioactivities. This review summarizes 155 indolediketopiperazines that were discovered from marine-derived fungi from 2000 to early 2019 and primarily focuses on their chemical diversity and biological function.
Research Paper
Diversification of amphioxus and vertebrate Cerberus protein function in modulating Nodal, BMP and Wnt signals
Yan-Jun Zhang, De-Li Shi
2020, 2(1): 16-23. doi: 10.1007/s42995-019-00024-z
HTML PDF Springerlink
Abstract:
Cerberus is a multifunctional antagonist implicated in embryonic patterning through modulation of Nodal, BMP and Wnt signals. Although its function is largely conserved in chordates, certain activities have diverged, even among vertebrates. Moreover, the antagonistic action of Cerberus from the basal chordate amphioxus toward Nodal, BMP and Wnt signals remains elusive. Here, we compared the activity of amphioxus and Xenopus Cerberus proteins using cross-species assays. We found that amphioxus and Xenopus Cerberus proteins display similar activities in antagonizing Nodal-induced events, but they exhibit both shared and distinct activities in modulating BMP and Wnt signals. Amphioxus Cerberus has reduced neuralizing activity that is dependent on inhibition of BMP signaling, and it modulates the signals of a restricted subset of Wnt proteins. Furthermore, we revealed that Xenopus Cerberus interacts with Wnt4 and Wnt11 to activate canonical Wnt signaling, whereas amphioxus Cerberus lacks this activity. These differences may be correlated with the divergence in the N-terminal region of Cerberus proteins between amphioxus and Xenopus. Our results indicate that chordate Cerberus proteins have evolved sub-functionalities that depend not only on their concentrations, but also on the properties of BMP and Wnt signals. This may account for their evolutionary distinct functions in different patterning processes.
Development of Amphioctopus fangsiao (Mollusca: Cephalopoda) from eggs to hatchlings: indications for the embryonic developmental management
Dianhang Jiang, Xiaodong Zheng, Yaosen Qian, Qingqi Zhang
2020, 2(1): 24-30. doi: 10.1007/s42995-019-00009-y
HTML PDF Springerlink
Abstract:
Amphioctopus fangsiao is an important fishery resource in northern coastal China, and there is an interest to develop its commercial cultivation under controlled conditions. In this study, we describe the embryonic development of A. fangsiao from eggs to hatchlings, focusing on the formation of the mantle, eyes and arms. Results indicate that this species has several favorable characteristics for aquaculture, such as a short incubation period and a large body size of hatchlings. During the organogenesis, the primordia of organs, including the optic sac and arm crown, first appeared at stage Ⅷ; then the mantle primordium, eye primordia and arm crown become visible at stage Ⅸ-Ⅹ, and the rudiment of embryo (mantle, eyes and arms) was completely outlined at stage Ⅺ. The retinal pigment appeared yellowish at stage Ⅹ-Ⅺ and gradually deepens in pigmentation in the subsequent stages, turning from yellowish to yellow, red, dark-red and eventually black. At stage ⅩⅤ, the primary lid fold, with only a circular opening remaining, covered the eye, and the dorsal ocular edge did not reach the ventral side until hatching (day 1-7). Afterwards, about 24 days after hatching, both the dorsal and ventral sides of eyelid could contract freely, with an oval and elongate slit remaining that was a miniature version of the adult morphology. The chromatophores and ink sac appeared at stage ⅩⅣ. These observations provide a foundation for the reproductive biology and aquaculture of A. fangsiao and also offer an important reference for the research of embryonic development in related species.
Effective Antarctic krill oil extraction using switchable hydrophilicity solvents
Weiwei Sun, Wencan Huang, Bowen Shi, Changhu Xue, Xiaoming Jiang
2020, 2(1): 41-49. doi: 10.1007/s42995-019-00019-w
HTML PDF Springerlink
Abstract:
Antarctic krill has been widely studied because of its abundant biomass, rich nutritional value, and great production potential. Notably, krill oil (KO) is rich in phospholipids (PLs), polyunsaturated fatty acids (PUFAs), and astaxanthin. A method based on a green switchable hydrophilicity solvent N, N-dimethylcyclohexylamine (DMCHA), which can reversibly change from oil soluble to water soluble in the presence of CO2 was used to extract KO from frozen Antarctic krill as it consumes less energy than traditional methods. We showed that DMCHA destroyed the surface structure of Antarctic krill and accelerated the dissolution of KO. In addition, this method enabled the PL extraction to reach up to 80.2% of total PLs, among which PC accounted for the highest proportion, up to 90.91% in PL. In fact, the astaxanthin extraction reached up to 81.44% of total astaxanthin while the fatty acid (FA) extraction up to 84.35%. The KO extracted through DMCHA was rich in PUFA, up to 47.74%, and the content of EPA + DHA reached 42.16% of total FA content. Furthermore, the amount of residual solvent in the lipid phase was just 0.23% of the DMCHA used for the extraction and the recovery rate of solvent was up to 93.2%. Our results demonstrated the high efficiency of oil extraction and the environmental friendliness of this method.
Effects of Bacillus subtilis on hepatic lipid metabolism and oxidative stress response in grass carp (Ctenopharyngodon idellus) fed a high-fat diet
Hui Zhao, Yan'er Luo, Yongan Zhang, Xiaoxuan Chen, Hui Wang, Daoyuan Guo, Zhixin Wu
2020, 2(1): 50-59. doi: 10.1007/s42995-019-00005-2
HTML PDF Springerlink
Abstract:
Bacillus subtilis is widely used in aquaculture as a probiotic. However, few studies have been conducted to examine the efect of B. subtilis on liver lipid metabolism. A total of 135 healthy grass carp (50.24 ± 1.38 g) were randomly divided into three groups: control (Con), high-fat diet (HF), and high-fat diet + B. subtilis (HF + B. subtilis), and fed for 8 weeks. The results showed that compared with the HF group, the weight gain rate (WGR) signifcantly increased (P < 0.05) and the hepatic lipid content, serum low-density lipoprotein cholesterol (LDL-C), and aspartate aminotransferase (AST) decreased in the group supplemented with B. subtilis (P < 0.05). Moreover, the hepatic mRNA expression of fatty acid synthase (FAS) was signifcantly down-regulated and the carnitine palmitoyl transferases (CPT1α1a) were up-regulated in the HF + B. subtilis group compared to the HF group (P < 0.05), respectively. Additionally, in the HF + B. subtilis group, glutathione (GSH) signifcantly increased (P < 0.05), while hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents signifcantly decreased compared to the HF group (P < 0.05). B. subtilis may reduce the hepatic lipid content by inhibiting its synthesis and promoting β-oxidation of fatty acids. B. subtilis may also alleviate dyslipidaemia and prevent oxidative damage in the liver caused by the high-fat diet of grass carp. Hence, dietary supplementation with B. subtilis shows promise as a therapeutic or preventive tool against fatty liver disease.
Vertical variation in Vibrio community composition in Sansha Yongle Blue Hole and its ability to degrade macromolecules
Bei Li, Jiwen Liu, Shun Zhou, Liang Fu, Peng Yao, Lin Chen, Zuosheng Yang, Xiaolei Wang, Xiao-Hua Zhang
2020, 2(1): 60-72. doi: 10.1007/s42995-019-00003-4
HTML PDF Springerlink
Abstract:
With the advantages of wide distribution,fast growth,and broad metabolic spectrum to organic carbon compounds,Vibrio may play an important role in organic carbon cycling. However,the ecological roles of Vibrio in many marine environments have not been explored. Here,the world's deepest 'blue hole',the Sansha Yongle Blue Hole (SYBH) in the South China Sea,which is a geographically semi-enclosed environment featuring unique chemical characters,was investigated. The abundance,diversity and carbon source utilization capability of Vibrio were studied by quantifcation and high-throughput sequencing of Vibrio specifc 16S rRNA genes and cultivation methods. The abundance of Vibrio in water column of the SYBH ranged from 3.78 ×104 to 7.35 ×106 16S rRNA gene copies L-1. Free-living Vibrio was more abundant than particle-associated Vibrio (~1.20×106 versus~2.68×105 gene copies L-1),indicating that Vibrio prefers a free-living life style. The Vibrio assemblages showed clear vertical stratifcation and could be divided into three groups: aerobic-transition,middle anaerobic and bottom anaerobic zones. Dissolved oxygen (DO),temperature,pH and salinity were the main environmental factors afecting the abundance and community composition. Cultivated Vibrio demonstrated a degrading capability to various macromolecular substrates,including starch,Tween 20/40/80,DNA,gelatin,alginate,casein,chitin,lecithin,κ-carrageenan,mannan,xylan and hyaluronic acid. This suggests that Vibrio could produce a variety of highly active extracellular enzymes. Our study provides new insights into the distribution pattern and possible role in carbon cycle of Vibrio in the unique environment of a 'blue hole'.
Microbial diversity of sediments from an inactive hydrothermal vent field, Southwest Indian Ridge
Zhifeng Yang, Xiang Xiao, Yu Zhang
2020, 2(1): 73-86. doi: 10.1007/s42995-019-00007-0
HTML PDF Springerlink
Abstract:
The Southwest Indian Ridge, which is the slowest-spreading of the main ridges, separates the African and Antarctic plates. The slow expanding rate is associated with less density of hydrothermal vent fields, shorter longevity of hydrothermal activity, cold mantle temperatures and thick lithosphere. However, the microbial communities adapting to such specific characteristics of this area have remained largely unexplored. To study the microbial diversity at the Southwest Indian Ridge, we sampled three sediment cores in a newly found inactive vent field, the Tianzuo field, and used high-throughput sequencing of 16S rRNA genes to reveal the microbial composition. Microbial communities of three sampling sites were very similar at the surface, and underwent a gradient change along depth. Gammaproteobacteria, namely Alteromonadaceae, Nitrosococcus and the JTB255 marine benthic group, were the most dominant bacterial taxa. Marine Group Ⅰ was the dominant archaeal taxon in our samples. In addition, microbial populations capable of ammonia oxidation, nitrite oxidation, sulfur oxidation and manganese oxidation were detected to be the main chemolithoautotrophs. The enrichment of sulfur-oxidizing and manganese-oxidizing bacteria was observed in deep layers. When compared with other vent fields along different ocean ridges, the Tianzuo field showed distinct composition in both archaeal and bacterial communities. These results provide the first view of microbial communities of the Tianzuo field at the Southwest Indian Ridge, and give a better understanding of metabolic potential possessed by the microbial populations.
The differentiation of iron-reducing bacterial community and iron reduction activity between riverine and marine sediments in the Yellow River estuary
Hongxia Zhang, Fanghua Liu, Shiling Zheng, Lei Chen, Xiaoli Zhang, Jun Gong
2020, 2(1): 87-96. doi: 10.1007/s42995-019-00001-6
HTML PDF Springerlink
Abstract:
Rivers are the primary contributors of iron and other elements to the global oceans. Iron-reducing bacteria play an important biogeochemical role in coupling the iron and carbon redox cycles. However, the extent of changes in community structures and iron reduction activities of iron-reducing bacteria in riverine and coastal marine sediments remains unclear. This study presents information on the spatial patterns and relative abundance of iron-reducing bacteria in sediments of the Yellow River estuary and the adjacent Bohai Sea. High-throughput sequencing of bacterial 16S rRNA found that the highest relative abundances and diversities were from the estuary (Yellow River-Bohai Sea mixing zone). Pseudomonas, Thiobacillus, Geobacter, Rhodoferax and Clostridium were the most abundant putative iron-reducing bacteria genera in the sediments of the Yellow River. Vibrio, Shewanella and Thiobacillus were the most abundant in the sediments of the Bohai Sea. The putative iron-reducing bacterial community was positively correlated with the concentrations of total nitrogen and ammonium in coastal marine sediments, and was significantly correlated with the concentration of nitrate in river sediments. The riverine sediments, with a more diverse iron-reducing bacterial community, exhibited increased activity of Fe(Ⅲ) reduction in enrichment cultures. The estuary-wide high abundance of putative iron-reducing bacteria suggests that the effect of river-sea interaction on bacterial distribution patterns is high. The results of this study will help the understanding of the biogeochemical cycling of iron in riverine and coastal marine environments.