Jintian Huang

Cloning of lipoprotein lipase (LPL) and the effects of dietary lipid levels on LPL expression in GIFT tilapia ( Oreochromis niloticus )

Genetically improved farmed tilapia (GIFT) (Oreochromis niloticus) is an important aquaculture species. Lipoprotein lipase (LPL) is considered as a key enzyme in lipid metabolism and deposition. The present study was conducted to investigate the nutritional regulation of LPL in GIFT. We cloned and characterized the LPL gene from GIFT. Finally, we determined the effects of dietary lipid levels and refeeding on hepatic LPL gene expression in GIFT. The LPL gene of GIFT (Oreochromis niloticus) (O.nLPL) was 2,298xa0bp in length and encoded 515 amino acids. Sequence analysis showed that O.nLPL shared 57.3–87.9xa0% identity with LPLs from other piscine species. To study LPL expression patterns, juveniles GIFT were fed diets containing 3.7, 7.7 or 16.6xa0% crude lipid for 90xa0days and the expression of hepatic O.nLPL was examined using real-time PCR. The abundance of hepatic LPL mRNA increased with increasing dietary lipid. The expression of O.nLPL mRNA in the 16.6xa0% dietary lipid group was significantly higher than that of the 3.7xa0% lipid group (Pxa0<xa00.05). The expression of O.nLPL was increased in GIFT following a 48-h fast and decreased 12xa0h after refeeding. Hepatic LPL mRNA returned to fasting levels 48xa0h after refeeding. In summary, high dietary lipid induced expression of liver O.nLPL, and expression of liver LPL is regulated by fasting and refeeding.

Changes of globins expression in tongue sole, Cynoglossus semilaevis (Actinopterygii: Pleuronectiformes: Cynoglossidae) in response to short-term hypoxia

Aquatic hypoxia, a complex ecological phenomenon, can cause major metabolic changes and influence foetal growth and development of all organisms living in water (Kajimura et al. 2004). With the increased industrialization and urbanization of coastal zones in recent years, hypoxia has grown strikingly in aquatic systems and has received much attention in biomedical research (Gray et al. 2002, Wawrowski et al. 2011). Fishes are the main aquatic animals that are first affected by hypoxia, and so fishes have become a prime model to investigate hypoxia tolerance strategies at the organism level (Roesner et al. 2008). Under hypoxia, a variety of physiological, anatomical and behavioural mechanisms were activated in fish that enables fish to survive in this condition. One of the main mechanisms relies on the globins to enhance the O2 transport capacitance, facilitate intracellular O2 diffusion, or enable O2 storage for hypoxia. To date, many types of globins have been identified in vertebrates. Hemoglobin (Hb) is a heterotetramer that consists of two α and two β chains. Hb is located in the erythrocytes and serves for the transport of O2. Myoglobin (Mb) is a monomeric protein and mainly included in the myocytes of the heart and skeletal muscles to store oxygen and to facilitate intracellular oxygen diffusion (Wittenberg and Wittenberg 2003). Neuroglobin (Ngb) is mainly resided in the central and peripheral nervous system (Burmester et al. 2000) and may supply O2 to metabolically active neurons. Cytoglobin (Cygb) is expressed in the fibroblast cells and distinct neurons, and may be involved in reactive oxygen species detoxications or in the function of supplying oxygen to particular enzymatic reactions (Burmester et al. 2002, Schmidt et al. 2004). Those four globins (Hb, Mb, Ngb, and Cygb) have been ACTA ICHTHYOLOGICA ET PISCATORIA (2011) 41 (3): 179–184 DOI: 10.3750/AIP2011.41.3.05

Transcriptome analysis and discovery of genes involved in immune pathways from coelomocytes of Onchidium struma after bacterial challenge

ABSTRACT Onchidium struma widely distributes in subtidal and low‐tidal zones, which is considered to be an economical species with rich nutrition, a valuable biomonitor for heavy metal pollution and a representative species for evolution from ocean to land. However, there is limited genetic information available for O. struma development. This study compared transcriptomic profiles of coelomocytes from normal and bacteria infected O. struma by Illumina‐based paired‐end sequencing to explore the molecular immune mechanism of O. struma against bacterial infection. After assembly, a total of 92,450 unigenes with an average length of 1019 bp were obtained. Approximately 34,964 (37.82%) unigenes were annotated in the Nr NCBI database and 40.1% of unigenes were similar with that of Aplysia californica. Among them, 7609 unigenes were classified into three Gene Ontology (GO) categories: biological process (3250 unigenes, 42.7%), cellular component (2,281, 30.0%) and molecular function (2078 unigenes, 27.3%). A total of 22,776 unigenes were aligned to the Clusters of Orthologous Groups (COG) of proteins and classified into 25 functional categories. Following bacterial infection, 10,623 differently expressed unigenes (DEGs) were identified, including 7644 up‐regulated and 2979 down‐regulated unigenes. Further KEGG analysis annotated 11,681 DEGs to 42 pathways, and 11 pathways were identified to be related with diseases and immune system. To our knowledge, it was first time to analyze transcriptome profiles of O. struma. Results of the present study will provide valuable theoretical resources for future genetic and genomic research on O. struma. The research results will be helpful for improving the efficiency and quality of artificial breeding, establishing genetic linkage map, and enhancing health management for this species. HighlightsThe coelomocytes cDNA libraries of Onchidium struma were constructed and completed.Totally 92,450 unigenes were obtained from transcriptome profile of O. struma.10,623 unigenes were identified with 7644 up‐ and 2979 down‐regulated unigenes.Several immune signaling pathways including TLR, PI3K/ATK and TNF were analyzed.A total of 42,347 SSRs and 80,000 candidate SNPs loci were identified.