Effects Of N-3 HUFA On The Reproductive Performance, Offspring Growth Performance, Lipid Metabolism Of Siberia Sturgeon(Acipenser Baeri Brandt)

Siberian sturgeon(Acipenser baerii Brandt), a kind of ancient chondrostei, plays an important role in the evolutionary of fish and is also a crucial economic fish species in China, with more than 80% of cultured production in the world. The present studies were conducted to research the effects of dietary n-3HUFA levels on broostock reproductive performance, lipornetabolism and larve quality; The effects of dietary DHA/EPA on the early development and performance, antioxidant response; To study the early programming of low n-3HUFA diets on the post long-term performance of Siberian sturgeon. The summaries of the four sections of the study were shown as following:Cloning and Squence Analysis of Full-Length c DNAs of Peroxisome Proliferator-Activated Receptor α, Lipoprotein Lipase and Hepatic Lipase in Liver of Siberin SturgenThe full-length c DNAs of peroxisome proliferator-activated receptor α(PPARα), lipoprotein lipase(LPL) and hepatic lipase(HL) were cloned from Siberian sturgeon(Acipenser baerii) liver using reverse transcription-phosphatase chain reaction(RT-PCR) and rapid amplification of c DNA end(RACE) methods. The results show as follows: the full-length c DNA of PPARα in liver of Siberian sturgeon(Gen Bank accession No. KJ534588) was 1 736 bp, including a 5’ untranslated region of 158 bp, an open reading frame(ORF) of 1 401 bp and a 3’ untranslated region of 177 bp, the open reading frame(ORF) of 1 401 bp encoding a polypeptide of 466 amino acids with a theoretical molecular weight of 52.3 ku and shared 75.5% to 82.4% similarity with other PPARα genes. The full-length LPL c DNA of Siberian sturgeon(Gen Bank accession No. KJ720972) was 1 760 bp, including a 5’ untranslated region of 163 bp, an open reading frame(ORF) of 1 506 bp and a 3’ untranslated region of 91 bp, the ORF of 1 506 bp encoding a polypeptide of 501 amino acids with a theoretical molecular weight of 57.1 KD, and shared 48.7% to 67.0% similarity with other LPL genes. The full-length HL c DNA of Siberian sturgeon(Gen Bank accession No. KJ720973) was 1 740 bp, including a 5’ untranslated region of 124 bp, an open reading frame(ORF) of 1 500 bp and a 3’ untranslated region of 116 bp, the ORF of 1 500 bp encoding a polypeptide of 499 amino acids with a theoretical molecular weight of 56.4 KD, and shared 55.4% to 67.1% similarity with other HL genes. Phylogenetic tree analysis reveals that PPARα of Siberian sturgeon is closer with higher vertebrates, but LPL and HL are closer with other fish. In this study, the genes homology and phylogenetic status of PPARα, HL and LPL from Siberian sturgeon were analyzed, and the results provided basic data to further study the regulatory mechanism of lipornetabolism in Siberian sturgeon.Effect of Dietary n-3HUFA Levels on Broodstock Reproductive Performance, Lipid Metabolism and Larval QualityTwo groups of different n-3HUFA level(2.95%, 1.79%) diets were designed for the experiment. The group fed the trial diet with 2.95% n-3HUFA level named H, and the other group named L. During the 11 months trial, the fish were fed twice a day. Reproductive performance indices were recorded when broodstock spawning. The larvae were divide into 4 groups according to the different parents, and the 4 groups were respectively named D1(H♀×H♂)、D2(H♀×L♂)、D3(L♀×H♂)、D4(L♀×L♂). The results shows that the egg size of H group was significantly higher than that of group L; there were no significantly difference of VAP, ALH, BCF, MAD between the two groups in male fish, but VCL and VSL of the group H were significantly higher than those of group L. The TC and HDL in broodstock serum had no difference between the two groups, but the TG and LDL of H group were significantly higher than those of group L The serim MDA of group H was significantly decreased compared to that of group L(P<0.05). The serum SOD and T-AOC were significantly higher than those in group L. The larval survical of group D1 and D2 were significantly higher than group D3 and D4 at 7dph and 30 dph. SGR and FBW of group D4 were the lowst among the four groups and were significantly lower than group D2. These results suggested that DHA is important to improve the reproductive performance of male and female broodstock of Siberian sturgeon and the offspring quality. Effect of Dietary DHA/EPA Ratio on Growth, Antioxidant Response, Expression of Genes Related to Lipid Metabolism in Larvae of Siberia SturgeonA 30 d growth study was conducted to evaluate the impact of the diets DHA/EPA ratio on growth performance, lipid metabolism and antioxidant response of the Siberian sturgeon larvae. Siberia sturgeon larvae were randomly divided into 12 tanks for 4 treatments with 800 fish per tank in a recirculation system. Four isonitrogenic and isoenergetic microcapsuled diets were formulated with virous DHA/EPA ratios-1.33(R1.33), 1.86(R1.86), 2.25(R2.25), 2.75(R2.75). The results shows that the FBW and WG of the group R2.75 is the highest amomg groups(P<0.05). The CF, VSI, SR were not different(P>0.05). The CAT activity of group R2.75 and R2.25 was significantly higher than that of group R1.33 and R1.86(P<0.05), but SOD, T-AOC, MDA, TC, TG, HDL, LDL were not different among groups(P>0.05) in the visceral mass. The expression of PPARα and LPL had no difference in four groups but the expression of HL in group R2.25 and R2.75 was significantly higher than those of group R1.33(P<0.05). In a conclusion, there was better growth performance of larvae fed wtih the diet DHA/EPA ratio 2.75, and the larvae body fatty acid composition was influenced by proportion of DHA and EPA significantly. The antioxidant ability could be improved with the high proportion of DHA and EPA. However, the effect of proportion to the larvae lipid metabolism was not significant.Study on the Effects of Low n-3HUFA Stimulus at Early Feeding on Growth, Lipid Metabolism and Antioxidant Response in Larvae of Siberian SturgeonBased on the concept of nutritional programming we performed the experiment with the purpose to study on the effect of Early Nutritional Programming to the Siberian sturgeon larvae in antioxidant response and lipid metabolism during the post long term growth trial. During the start feeding period, fish were divided into 2 groups, named group H and L. Fish of group H was fed the diets with 2.32% n-3 HUFA, and group L was fed the the diets with 0.54% n-3 HUFA. After 32 days feeding, two groups were fed diet with the same diet with 2.02% n-3HUFA during 33- 55 dph, and after then fed diet with 0.27% n-3HUFA diet during day 56-77 dph. The results showed that, the FBW and SGR of group H were significantly higher than those of the group L during the first feeding period(P<0.05), the SR between two groups were not significant(P>0.05). However, during the 33-55 dph, growth rate were found much higher in previously L group than that of H group. Although the FBW of the group L were still significantly lower(P<0.05). Finally, during the period of 56-77 dph, growth performance was not different between the two groups. Antioxidant indexes had no difference between two groups during 33-77dph(P>0.05). The total DHA、EPA and n-3HUFA level of the group L were significantly lower than the level of the group H(P<0.05) at 77 dph in the whole body. The gene PPARα, HL and LPL expression of the visceral mass in group H were significantly higher(P<0.05) than those in group L at 18 dph. The gene LPL expression of the visceral mass in group H was significantly higher(P<0.05) than it in group L, but the gene PPARα, HL expression were not significantly different in two groups at 32 dph. The gene PPARα, HL and LPL expression were not significantly different in two groups at 77 dph. In a conclusion, the low n-3HUFA diet in larvae could affect the growth rate and lipids metabolic pathways of Siberian sturgeon for a long term.