Valuation of Ecosystem Services for the Sustainable Development of Hani Terraces: A Rice-Fish-Duck Integrated Farming Model.

As a complementary and symbiotic agro-ecological cycle system, a nature-based integrated rice-fish-duck farming ecosystem was developed in the Honghe Hani Rice Terraces. The main research objective was to evaluate the ecosystem services based on case studies of the Hani integrated rice-fish-duck terraced farming system and determine its potential and its importance as an ecological asset. We developed a valuation model to assess the value of the integrated farming system based on the three aspects of provisioning, regulation and maintenance, and cultural services; we selected eight groups and 10 indictors to evaluate the ecosystem services of the integrated ecosystem in Honghe Hani Rice Terraces was 3.316 billion CNY, of which the provisioning service value was 1.76 billion CNY, the regulation and maintenance service value was 1.32 billion CNY, and the cultural services value was 230.85 million CNY. The evaluation will be useful as a theoretical reference for poverty alleviation policy makers in similar poverty-stricken areas, enabling them to better protect and promote this mode of farming and further promote the protection of the natural environment and cultural heritage alongside the sustainable development of natural resources and human well-being.

Developmental Expression of HSP60 and HSP10 in the Coilia nasus Testis during Upstream Spawning Migration.

Heat shock protein 60 (HSP60) and heat shock protein 10 (HSP10) are important chaperones, which have been proven to have essential roles in mediating the correct folding of nuclear encoded proteins imported to mitochondria. Mitochondria are known as the power house of the cell, with which it produces energy and respires aerobically. In this regard, the obtained HSP60 and HSP10 have typical characteristics of the HSP60/10 family signature. Their mRNA transcripts detected were highest during the developmental phase (in April), while the lowest levels were found in the resting phase (after spawning in late July). Additionally, the strongest immunolabeling positive signals were found in the primary spermatocyte, with lower positive staining in secondary sperm cells, and a weak or absent level in the mature sperm. At the electron microscopic level, immunogold particles were localized in the mitochondrial matrix. Data indicated that HSP10 and HSP60 were inducible and functional in the Coilia nasus testis development and migration process, suggesting their essential roles in this process. The results also indicated that HSP60 may be one indicator of properly working mitochondrial import and refolding in the fish testis. This study also provides an expanded perspective on the role of heat shock protein families in spawning migration biology.

Whole genome sequencing of Chinese clearhead icefish, Protosalanx hyalocranius.

Background: Chinese clearhead icefish, Protosalanx hyalocranius , is a representative icefish species with economic importance and special appearance. Due to its great economic value in China, the fish was introduced into Lake Dianchi and several other lakes from the Lake Taihu half a century ago. Similar to the Sinocyclocheilus cavefish, the clearhead icefish has certain cavefish-like traits, such as transparent body and nearly scaleless skin. Here, we provide the whole genome sequence of this surface-dwelling fish and generated a draft genome assembly, aiming at exploring molecular mechanisms for the biological interests. A total of 252.1 Gb of raw reads were sequenced. Subsequently, a novel draft genome assembly was generated, with the scaffold N50 reaching 1.163 Mb. The genome completeness was estimated to be 98.39 % by using the CEGMA evaluation. Finally, we annotated 19 884 protein-coding genes and observed that repeat sequences account for 24.43 % of the genome assembly. We report the first draft genome of the Chinese clearhead icefish. The genome assembly will provide a solid foundation for further molecular breeding and germplasm resource protection in Chinese clearhead icefish, as well as other icefishes. It is also a valuable genetic resource for revealing the molecular mechanisms for the cavefish-like characters.

Changes of gonadotropin-releasing hormone receptor 2 during the anadromous spawning migration in Coilia nasus.

BACKGROUND: An increase in the activity of the pituitary-gonad axis (PG-axis) and gonad development are essential for the onset of spawning migration in teleosts. In the fish Coilia nasus, gonad development and spawning migration up the Yangtze River occurs by the end of each summer. We hypothesized that gonadotropin releasing hormones receptor 2 (GnRH-R2), which together produce a signal that interacts with the PG-axis, may help to regulate spawning migration processes. RESULTS: In this regard, we (1) characterized the gonadosomatic index (GSI) in the anadromous fish C. nasus; (2) analyzed the GnRH-R2 mRNA expression levels in ovary and brain, and concentrations in the serum; and (3) identified the GnRH-R2 protein distribution in the brain and ovaries. We found strong relationships between all of these indices. CONCLUSIONS: The results indicate that GnRH-R2 could act together to promote spawning during the anadromous migration. There is some evidence that the GnRH-R2 gene expression levels and protein distributions change in association with the migratory behavior.

Molecular Characteristic, Protein Distribution and Potential Regulation of HSP90AA1 in the Anadromous Fish Coilia nasus.

Heat shock proteins play essential roles in basic cellular events. Spawning migration is a complex process, with significant structural and biochemical changes taking place in the adult gonad. To date, the molecular mechanisms underlying migration reproductive biology remain undetermined. In this regard, a full length HSP90AA1 comprising 2608 nucleotides from the anadromous fish Coilia nasus was characterized, encoding 742 amino acid (aa) residues with potential phosphorylation sites. HSP90AA1 mRNA transcripts were detected in all organs, especially in the gonad. Furthermore, the greatest transcript levels were found during the developmental phase, while the lowest levels were found during the resting phase. In addition, the strongest immunolabeling positive signal was found in the primary spermatocyte and oocyte, with lower positive staining in secondary germ cells, and a weak or absent level in the mature sperm and oocyte. Interestingly, HSP90AA1 was mainly located in the cytoplasm of germ cells. These results are important for understanding the molecular mechanism of anadromous migration reproductive biology. In combination with data from other fish species, the result of this present study may facilitate further investigations on the spawning migration mechanism.

Complete mitochondrial genome of Lateolabrax maculatus.

In this study, we sequence the complete mitochondrial genome of Lateolabrax maculatus. This mitochondrial genome is 16,597 bp in length, encoding 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and a non-coding control region as found in other vertebrates, with the gene synteny identical to those of typical vertebrates. Control region (D-Loop), of 929 bp in length, is located between tRNA(Pro) and tRNA(Phe). The overall base composition of the heavy strand shows T 25.9%, C 29.5%, A 27.3% and G 17.3%, with an AT bias of 53.2%.

Testes transcriptome profiles of the anadromous fish Coilia nasus during the onset of spermatogenesis.

RNA-Seq technology has been widely applied to transcriptomics, genomics and functional gene study. Here, we performed de novo transcriptome sequencing to produce 23,842,172 clean reads representing a total of 4,815,798,404 (4.8 Gb) nucleotides from comprehensive transcript dataset for testis of Coilia nasus. Over 20 million Illumina reads were assembled into 194,636 unigenes, and 42,642 annotated genes were predicted by Blastx and ESTScan, respectively. Applying Blast analysis and functional annotation (e.g., GO, COG, SwissProt and KEGG) using the assembled gene models from catalogs of other species, we have sampled an extensive and diverse expressed gene catalog for C. nasus representing a large proportion of the genes involved in the onset of spermatogenesis. The results will provide a general clue to the potential spermatogenesis molecular mechanisms for this species.

Ovary transcriptome profiling of Coilia nasus during spawning migration stages by Illumina sequencing.

Coilia nasus is an anadromous kind of small to moderate size fish species, and limited transcriptomics research has been performed. In the present study, we performed Illumina sequencing to produce a 22,996,612 clean reads representing with a total of 4,599,079,601 (4.5Gb) nucleotides comprehensive transcript dataset for ovary of C. nasus. Over 20 million total reads were assembled into 63,141 unigenes, and 27,027 annotated genes were predicted by Blastx and ESTScan, respectively. Applying Blast analysis and functional annotation (e.g., GO, COG, Swissprot and KEGG), we have sampled an extensive and diverse expressed gene catalog for C. nasus representing a large proportion of the genes expressed in the ovary development process. This approach will assist in the discovery and annotation of novel genes that play key roles in anadromous fish spawning migration process.

Characteristic of PGDS potential regulation role on spermatogenesis in the Chinese mitten crab Eriocheir sinensis.

Prostaglandin D synthase (PGDS) catalyzes the isomerization of PGH2 to produce PGD2 in the presence of sulfhydryl compounds. In this study, a full length PGDS gene comprising 1250 nucleotides from the Chinese mitten crab Eriocheir sinensis (Es-PGDS) was characterized, with a 615 bp open reading frame encoding 204 amino acid residues. Its deduced peptide has high homology with other species' PGDS protein. The Es-PGDS mRNA expression was tissue-related, with the highest expression observed in the hepatopancreas, accessory sex gland, testis and ovaries. We also detected the different stages of tissue expression and the enzyme activity for Es-PGDS in the testis and male crab hepatopancreas. The different expression patterns and its corresponding enzyme activity level indicated that PGDS is involving in the regulation of reproductive action during the period of rapid development in E. sinensis. Furthermore our research could arouse a heat debate on the PGDS reproductive function in invertebrate and further study will be needed to determine the molecular mechanism(s) linking PGDS functions to spermatogenesis and ontogenesis if this gene is to be exploited as a molecular biomarker in further studies of development.

Molecular cloning and expression analysis of chymotrypsin-like serine protease from the redclaw crayfish (Cherax quadricarinatus): a possible role in the junior and adult innate immune systems.

A novel chymotrypsin-like serine protease (CLSP) was isolated from the hepatopancreas of the redclaw crayfish Cherax quadricarinatus (Cq-chy). The full-length cDNA of Cq-chy contains 951 nucleotides encodes a peptide of 270 amino acids. The mature peptide comprising 223 amino acids contains the conserved catalytic triad (H, D, and S). Similarity analysis showed that Cq-chy shares high identity with chymotrypsins from the fiddler crab; Uca pugilator. Cq-chy mRNA expression in C. quadricarinatus was shown to be: (a) tissue-related with the highest expression in the hepatotpancreas and widely distributed, (b) highly responsive in the hepatopancreas to White Spot Syndrome Virus (WSSV) challenge, and (c) differently regulated in immature and adult crayfish. In this study we successfully isolated Cq-chy. Our observations indicate that Cq-chy is differently involved in the immature and adult innate immune reactions, thus suggesting a role for CLSPs in the invertebrate innate immune system.