The NEW GIFT Nile tilapia （Oreochromis niloticus niloticus L.） is a nationally certificated new strain selected over 14 years and 9 generations from the base strain of GIFT Nile tilapia, introduced in 1994. This new...The NEW GIFT Nile tilapia （Oreochromis niloticus niloticus L.） is a nationally certificated new strain selected over 14 years and 9 generations from the base strain of GIFT Nile tilapia, introduced in 1994. This new variety has been extended in most of areas of China. The management of genetically improved strains, including the genetic markers for identification is needed urgently. RAPD analysis was conducted and their conversion to SCAR markers was developed. From NEW GIFT Nile tilapia, two strain-specific RAPD bands, S304624 bp and S36568 bp were identified. The strain-specific RAPD bands were gel-purified, cloned, and sequenced. Locus-specific primers were then designed to amplify the strain-specific bands. PCR amplification was conducted to test the variations in allele frequencies of two converted SCAR markers among the NEW GIFT Nile tilapia and its base strains, as well as 7 additional farmed strains worldwide. The frequency of SCAR marker Ⅰ （553 bp） was 85.7% in NEW GIFT Nile tilapia, but 16.7% in the base strain. The frequency of SCAR marker Ⅱ （558 bp） was 91.4% in NEW GIFT Nile tilapia, but 0% 70% in the 7 other strains. In order to confirm the utility of these two markers, an examination was conducted for a wild population from Egypt, resulted the frequency of SCAR Ⅰ and Ⅱ was 10% and 70%, respectively, much lower than that of New GIFT strain. The increase in allele frequency of these two SCAR markers suggests that these markers might be genetically linked to the quantitative trait loci （QTL） underlining the performance traits by long term selection, and indicate the bright potential of SCAR marker technology for tracking generations during selection progress and for distinguishing among genetically improved strain and other strains.展开更多
This study aimed to investigate the effects of copper and manganese on hemocyte apoptosis and the antagonism of iron and zinc in Oreochromis niloticus The heavy metal contents in fish blood and feed were determined by...This study aimed to investigate the effects of copper and manganese on hemocyte apoptosis and the antagonism of iron and zinc in Oreochromis niloticus The heavy metal contents in fish blood and feed were determined by atomic absorption spectrophotometry, and the hemocyte apoptosis was determined by flow cytometry. A total of 360 tilapias were selected, and they were divided randomly and evenly into 12 groups. In the challenge groups, the tilapias were fed with con stant-level copper sulfate（0, 200 mg/kg） and manganese sulfate（0, 120 mg/kg）; in the antagonism groups, the tilapias were fed with constant-level zinc sulfate（20320 mg/kg） and iron sulfate（150, 350 mg/kg）. After 20-week aquaculture, the hemocyte apoptosis rates in the copper and manganese groups were significantly increased; with the increased addition levels of iron and zinc, the hemocyte apopto sis rates in the iron and zinc groups were significantly reduced, but they were stil higher than that in the control group. In conclusion, excessive copper and manganese can cause apoptosis in hemocytes of O. niloticus. However, the toxic effects of copper and manganese can be antagonized by iron and zinc.展开更多
基金National Tilapia Industry Technical System(nycytx-48-3)National Tilapia Seed Program(nyhyzx07-044-01)
文摘The NEW GIFT Nile tilapia （Oreochromis niloticus niloticus L.） is a nationally certificated new strain selected over 14 years and 9 generations from the base strain of GIFT Nile tilapia, introduced in 1994. This new variety has been extended in most of areas of China. The management of genetically improved strains, including the genetic markers for identification is needed urgently. RAPD analysis was conducted and their conversion to SCAR markers was developed. From NEW GIFT Nile tilapia, two strain-specific RAPD bands, S304624 bp and S36568 bp were identified. The strain-specific RAPD bands were gel-purified, cloned, and sequenced. Locus-specific primers were then designed to amplify the strain-specific bands. PCR amplification was conducted to test the variations in allele frequencies of two converted SCAR markers among the NEW GIFT Nile tilapia and its base strains, as well as 7 additional farmed strains worldwide. The frequency of SCAR marker Ⅰ （553 bp） was 85.7% in NEW GIFT Nile tilapia, but 16.7% in the base strain. The frequency of SCAR marker Ⅱ （558 bp） was 91.4% in NEW GIFT Nile tilapia, but 0% 70% in the 7 other strains. In order to confirm the utility of these two markers, an examination was conducted for a wild population from Egypt, resulted the frequency of SCAR Ⅰ and Ⅱ was 10% and 70%, respectively, much lower than that of New GIFT strain. The increase in allele frequency of these two SCAR markers suggests that these markers might be genetically linked to the quantitative trait loci （QTL） underlining the performance traits by long term selection, and indicate the bright potential of SCAR marker technology for tracking generations during selection progress and for distinguishing among genetically improved strain and other strains.
基金Supported by Scientific Operating Expenses of Hainan Province(11-201410-0009)~~
文摘This study aimed to investigate the effects of copper and manganese on hemocyte apoptosis and the antagonism of iron and zinc in Oreochromis niloticus The heavy metal contents in fish blood and feed were determined by atomic absorption spectrophotometry, and the hemocyte apoptosis was determined by flow cytometry. A total of 360 tilapias were selected, and they were divided randomly and evenly into 12 groups. In the challenge groups, the tilapias were fed with con stant-level copper sulfate（0, 200 mg/kg） and manganese sulfate（0, 120 mg/kg）; in the antagonism groups, the tilapias were fed with constant-level zinc sulfate（20320 mg/kg） and iron sulfate（150, 350 mg/kg）. After 20-week aquaculture, the hemocyte apoptosis rates in the copper and manganese groups were significantly increased; with the increased addition levels of iron and zinc, the hemocyte apopto sis rates in the iron and zinc groups were significantly reduced, but they were stil higher than that in the control group. In conclusion, excessive copper and manganese can cause apoptosis in hemocytes of O. niloticus. However, the toxic effects of copper and manganese can be antagonized by iron and zinc.
