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利用紫外线诱导进行栉江珧(Atrina pectinata)雌核发育单倍体的研究,用强度为2 561μW/(cm2.s)的紫外线(254nm)照射不同时间的精子与正常卵子受精展开实验。结果发现随照射时间的增加,卵裂率、早期胚胎存活率和D型幼虫发生率总体呈下降趋势,遗传失活的精子与正常卵子受精后其胚胎发育至D型幼虫前期停止。经紫外线照射的精子受精后所产生的单倍体胚胎发育速度慢于正常受精所产生的二倍体胚胎,各照射组均出现非整倍体。40 s照射组中卵裂率达到51.2%,D型幼虫发生率为0,单倍体率最高,达到36.8%,出现“Hertwig效应”。由于雌核发育单倍体的有效诱导既需要精子遗传物质失活、又需要保证较高的卵裂率,因而在强度2 561μW/(cm2.s)的紫外线下照射40 s是获得栉江珧雌核发育单倍体的最佳条件。 相似文献
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Effects of Dietary Ampitheoe sp. Powder on Growth and Lipid Contents of Litopenaeus vannamei北大核心CSCD
This experiment was conducted to investigate the effects of dietary Ampitheoe sp. powder on the growth and the contents of astaxanthin, triglyceride (TG), total cholesterol (TCHO) and fatty acids of Litopenaeus vannamei. A total of approximately 6 777 L. vannamei with an initial body weight of (1. 80 ± 0.72) g were randomly divided into 3 groups, and there were 3 replicates (753 shrimp per replicate) in each group. Those shrimp fed diets containing 0 (D0 group), 8. 25% (D8. 25 group) and 33% (D33. 00 group) Ampitheoe sp. powder, respectively. The feeding trial lasted for 40 days. The results showed as follows: 1) the final body weight, weight gain rate, specific growth rate, yield and survival rate in D33.00 group were significantly higher than those in D0 group (P <0.05), whereas the feed conversion ratio was significantly lower than that in D0 group (P <0.05) . However, there was no significant difference between D33.00 group and the D8. 25 group in those indexes (P >0.05) . 2) The astaxanthin content in carapace, hepatopancreas and muscle of L. vannamei in D8.25 and D33. 00 groups was significantly higher than that in D0 group (P < 0. 05); that in D33.00 group was significantly higher than that in D8. 25 group (P < 0. 05) . 3) TG content in haemolymph, hepatopancreas and muscle in D8. 25 and D33. 00 groups was significantly lower than that in D0 group (P < 0.05); the TCHO content in hepatopancreas in D8. 25 group was significantly higher than that in D0 and D33.00 groups (P <0.05); TCHO content in muscle in D33.00 group was significantly higher than that in D0 group (P <0.05) . 4) The contents of eicosapentaenoic acid (EPA) and arachidonic acid (AA) in hepatopancreas in D33.00 group were significantly higher than those in D0 group (P <0.05) . The EPA content in muscle in D33.00 group was significantly higher than that in D0 group (P < 0. 05) . In conclusion, adding Ampitheoe sp. powder into the diet can improve the growth performance, the contents of astaxanthin, EPA and AA in L. vannamei, and affect the accumulation of TG and TCHO, which can be used as a functional diet in aquaculture. Considering the cost, the supplementation level of 8. 25% Ampitheoe sp. powder is more appropriate. © 2023 Chinese Journal of Pediatric Surgery. All rights reserved. 相似文献
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