Genetic diversity in crucian carp (Carassius auratus)

A survey of restriction fragment polymorphism in mitochondrial DNA of three subspecies of Carassius auratus throughout four provinces in China was undertaken using 17 restriction enzymes. Two carp, Cyprinus carpio rubbrofuscus and Cyprinus carpio carpio, were included as the outgroup. A total of 16 haplotypes was observed: 5 in tetraploids of C. auratus auratus; 8 in hexaploids of C. auratus auratus; and 2 in C. auratus gibelio and C. auratus cuvieri, respectively. The tetraploids and hexaploids share three common haplotypes as I, V, and VI. C. a. Cuvieri may have diverged first among the three subspecies. Interestingly, C. a. auratus and C. a. cuvieri did not form monophyletic clades, which indicated that the classification of carassius auratus required further studies. The current hypothesis, that hexaploids originated from tetraploids by a polyploidy event, is less favorable, based on the distribution of haplotypes and the lower diversity in tetraploids than in hexaploids. Our data also indicate that divergence of hexaploids and tetraploids might be recent and mtDNA polymorphism existed before the divergence. Meanwhile, genetic isolation exists between the hexaploids and the tetraploids.

粪便收集时间和饲料中肉骨粉含量对异育银鲫(Carassius auratus gibelio)消化率的影响(英文)

本研究探讨了通过收集器不同粪便收集时间和饲料中肉骨粉( MBM)含量对异育银鲫干物质、蛋白、能量、磷的表观消化率(ADC)影响。不同梯度(0 ,20 ,40 ,60 ,80 ,100 %)的肉骨粉替代鱼粉(FM)蛋白配制成六种等氮(粗蛋白:410 g/kg)等能(总能:18 kJ/g)的饲料,通过11周的饲养实验,实验开始后2周开始收集粪便,收集时间分别是:排粪后1 min,投喂后4h和16h。结果表明,干物质、蛋白、能量、磷的消化率明显随粪便收集时间增加而升高(p<0 .05) ,但在高肉骨粉替代饲料中

由鲤(Cyprinus carpio)和鲫(Carassius auratus)染色体组叠加构建的两个单性人工多倍体克隆

具有天然雌核发育的多倍体杂种鱼可防止杂种优势的分离并保持其后代的杂种优势。由于假设诱发的多倍体鱼类的生殖模式是天然雌核发育的,我们进行了鲤鲫杂种的多倍体诱发,目的是描述经染色体组叠加由有性鲤鲫二倍体转化为异源三倍体及异源四倍体克隆谱系。鲤鲫杂种产生未减数而具有两亲本染色体组杂种卵子,未减数的雌核可与入卵的雄核融合叠加形成三倍体合子。鲤鲫异源三倍体胚胎发育正常,部分异源三倍体雌性个体可产生未减数的、仍保留母本的三套染色体的成熟卵子。绝大部分鲤鲫异源人工三倍体个体的成熟卵子的雌核不与入卵的雄核融合,具有天然雌

Cytological Mechanism on the Integration of Heterologous Genome or Chromosomes in the Unique Gynogenetic Carassius auratus gibelio

银鲫（ＣａｒａｓｉｕｓａｕｒａｔｕｓｇｉｂｅｌｉｏＢｌｏｃｈ）是行天然雌核发育生殖的两性型三倍体鱼类，与普通两性融合生殖鱼类相比，具有独特的育种优势。八十年代以来，异育银鲫、复合四倍体异育银鲫的发现表明，雌核发育卵子不但具有保持自身全部染色体的能力，还能整合异源精子的部分遗传物质或整个基因组，影响雌核发育后代的性状。因此，搞清楚异源基因组的整合机制对于进一步弄清其发育模式以及诱导复合多倍体银鲫均具有十分重要的作用。两性融合发育鱼类的精子入卵后，精核在促精核活化因子的诱导下，可以逐渐解凝并形成雄性原核；而在

Discovery of a male-biased mutant family and identification of a male-specific SCAR marker in gynogenetic gibel carp Carassius auratus gibelio

Gibel carp ( Carassius auratus gibelio) is a uniquely gynogenetic species with a minor ratio of males in natural habitats, but its male origin and sex determination mechanisms have been unknown. In this study, a male-biased mutant family was discovered from the gynogenetic gibel carp, and a male-specific SCAR marker was identified from the mutant family. Normal spermatogenesis was observed in the male testes by immuno. fluorescence histochemistry. Nearly identical AFLP profiles were observed between males and females, but a male-specific 86 bp AFLP fragment was screened by sex-pool bulked segregant analysis and individual screening. Based on the male-specific AFLP fragment, a total of 579 bp sequences were cloned by genome walking. Subsequently, a male-specific SCAR marker was designed, and the male-specific DNA fragment was confirmed to be steadily transmitted to the next generation and consistently detected only in males. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.

Characterization of the porcine differentially expressed PDK4 gene and association with meat quality

To investigate the differential expression of genes in the skeletal muscle between Yorkshire and Chinese indigenous breed Meishan pigs, suppression subtractive hybridization was carried out and many genes were proved to be expressed significantly different in the two breeds. One gene highly expressed in Meishan but lowly expressed in Yorkshire specific library, shared strong homology with human pyruvate dehydrogenase kinase 4 (PDK4). Using semi-quantity and quantity PCR, We confirmed its differential expression between the two breeds. Temporal and spatial expression analysis indicated that porcine PDK4 gene is highly expressed in skeletal muscle and the highest in neonatal pigs. Complete cDNA cloning and sequence analysis revealed that porcine PDK4 gene contains an open reading frame of 1,221 bp. The deduced amino acid sequence showed conservation in evolution. A G/A mutation in intron 9 was identified and association analysis showed that it was significantly associated with intramuscular fat, muscle water content.

Molecular characterization and expression pattern of AFPIV during embryogenesis in gibel carp(Carassiu auratus gibelio)

As a new type of AFPs, AFPIV has been firstly identified in longhorn sculpin (Myoxocephalus octodecimspinosus), and in recent years, its cDNA and amino acid sequence have been reported, and its pancreatic synthesis has been firstly reported in polar fish. However, its expression patterns during fish embryogenesis have not been elucidated yet. By differential screening, we cloned the CagAFPIV in gibel carp, Carassius auratus gibelio, demonstrated its predominant expression during embryogenesis. RT-PCR detection revealed that CagAFPIV was first transcribed from blastula stage and kept a high level during embryogenesis and declined remarkably in hatched larva. In situ hybridization revealed that CagAFPIV transcripts were firstly distributed over the margin and marginal blastomere in blastula stage embryos, at the early-gastrula stage the positive signals distributed in the marginal cells and the internalization cells, and later restricted to the cells the yolk syncytial layer (YSL) from later gastrula stage to larva stage. Consistently, the CagAFPIV protein also kept a high level during embryogenesis, and the high protein level retained some days after the larva hatched. Our work, for the first time, revealed the dynamic expression and distribution of CagAFPIV during embryogenesis.

The effect of different dietary iron levels on growth and hepatic iron concentration in juvenile gibel carp (Carassius auratus gibelio)

P>An 83-day growth trial was conducted using a flow-through system to examine the effects of different dietary iron levels on growth and hepatic iron concentration in juvenile gibel carp (Carassius auratus gibelio). Six purified diets supplemented with different levels of iron (0, 10, 30, 60, 100 and 200 mg kg(-1)) (as ferrous sulfate) were fed to triplicate groups of fish (initial weight 2.12 +/- 0.00 g per fish). The results showed that the addition of iron to the basal diet did not significantly affect the specific growth rate (SGR), feed efficiency (FE), survival, red blood cell amount (RBC), hemoglobin content (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) or mean corpuscular hemoglobin concentration (MCHC). Hepatic iron concentration and hematocrit (Hct) were significantly influenced by dietary iron level (P < 0.05). On the basis of the iron concentration for the maintenance of optimum hepatic iron concentration and Hct, it was concluded that the dietary iron concentration of juvenile gibel carp should be not less than 202 mg Fe kg(-1) diet.