猪RBP2和CRABP2基因的定位、组织表达谱分析、单核苷酸多态性研究及其关联分析

利用法国农业科学院-明尼苏达大学的辐射杂种克隆板（IMpRH）,将猪细胞视黄醇结合蛋白基因2（RBP2）和细胞视黄酸结合蛋白基因2（CRABP2）分别定位在猪13、4号染色体上。利用RT-PCR方法,克隆到了CRABP2的CDS全长。利用半定量的RT-PCR方法,对RBP2和CRABP2基因在成年五指山猪12种不同组织（肺、骨骼肌、脾、心脏、胃、大肠、淋巴结、小肠、肝、大脑、肾、脂肪）中的组织表达谱进行了研究。在这两个基因中共检测到了4个单核苷酸多态位点。在RBP2-C117T多态位点,利用基于聚合酶链式反应的限制性片段长度多态性（PCR-RFLP）方法,对其在莱芜黑猪、五指山小型猪、贵州小型猪、广西巴马小型猪和通城猪群中的分布进行了研究。在通城猪群中,进行了不同基因型与性状间的关联分析,发现其不同的基因型与肌肉大理石纹评分、肌肉嫩度高度相关。在猪的生产和育种中,这一多态位点可能会成为有用的分子标记。     

Dietary vitamin A requirements of juvenile Japanese flounder Paralichthys olivaceus

A 70‐day feeding experiment was conducted to assess the dietary vitamin A (VA) requirements of juvenile Japanese flounder (Paralichthys olivaceus). Six semi‐purified diets with VA supplementations of 0, 5000, 10 000, 15 000, 20 000 and 25 000 IU kg^?1 were fed twice a day to triplicate groups of 20 juveniles per tank with an initial weight of 1.59 ± 0.01 g (mean ± SE). Weight gain (WG) and specific growth rate (SGR) increased as dietary VA increased up to 10 000 IU kg^?1. Significantly lower WG and SGR were observed for the 0 IU kg^?1 treatment than for treatments of 5000, 10 000 and 15 000 IU kg^?1. Highest WG and SGR were observed in fish fed 10 000 IU kg^?1; slightly lower values were recorded in fish fed 15 000, 20 000 or 25 000 IU kg¹. No significant difference was observed in survival rate among treatments. Whole body total lipid was significantly higher in fish fed 0 and 5000 IU kg^?1 than for other levels. Reduced growth and small livers were observed as signs of VA deficiency in fish fed 0 IU kg^?1. Slightly reduced growth and pale fragile livers were observed as effects of VA excess in fish fed 25 000 IU kg^?1. Total retinol contents in liver and eyes increased with increasing levels of dietary VA. No retinol was detected in livers, and significantly lower total retinol content was observed in eyes, of fish fed 0 IU kg^?1. WG analysed by the broken line method indicated that an optimum dietary VA requirement of 9000 IU kg^?1.     

Preliminary system of rapid analysis of blood retinol level in cattle

Control of blood retinol levels in cattle during fattening is important in the production of marbled beef. However, it is difficult to easily measure the blood retinol concentration in the field. In this study, we attempted to develop an analysis method that does not require blood cell separation and uses a compact fluorescence analyzer that can be carried around as a preliminary system for measuring blood retinol concentration in the field. This system was used to monitor blood retinol levels in 12 fattening cattle (14 to 27 months old) and demonstrated a strong correlation (r = 0.78) with the results obtained by the standard high-performance liquid chromatography (HPLC) method. Stronger correlations (r = 0.87) were obtained until the cattle were 24 months of age. These results suggest that higher correlations can be expected to be obtained by improving the robustness of the extraction system. Refinements for practical use need to be considered, but whole blood extraction and the vitamin A analyzer that was developed show potential to be used for on-farm monitoring of retinol levels.     

Hyperostotic polyarthropathy in a rabbit - a suspected case of chronic hypervitaminosis A from a diet of carrots

Chronic hypervitaminosis A can occur in many species after excessive dietary intake of Vitamin A (retinol). The most common presentation of chronic hypervitaminosis A is a polyarthropathy with hyperostosis and ankylosis of various joints. This case report describes a probable case of naturally occurring hypervitaminosis A-induced polyarthropathy in a rabbit after chronic ingestion of a diet made up almost exclusively of carrots. Carrots do not contain retinol, but are rich in provitamin A (or beta-carotene). Rabbits are unique in that they can convert 100% of dietary beta-carotene into retinol. A syndrome of naturally occurring hypervitaminosis A-induced polyarthropathy has not been described in a rabbit before.     

Retinol Values in the Plasma of the Arabian Camel (Camelus dromedarius) and the Influence of Aflatoxicosis

The normal values are reported of the concentration of vitamin A (retinol) in the plasma of 44 male and female adult camels (Camelus dromedarius) in the United Arab Emirates. The concentrations of the vitamin in the plasma of eight camels of both sexes afflicted with aflatoxicosis were also determined. The mean concentration (±SD) of the vitamin in healthy camels was 460.1±49.3 ng/L. Sex had no significant effect on the concentration of the vitamin. Camels with aflatoxicosis had a mean concentration of retinol in the plasma of 243.4±32.3 ng/L. The concentrations of aflatoxins in the liver and ruminal contents of these animals were 18.2±1.3 and 243.4 g/kg, respectively.     

Chemical composition of dried eyeballs from <Emphasis Type="Italic">Euphausia superba</Emphasis> and <Emphasis Type="Italic">Euphausia pacifica</Emphasis>

ABSTRACT:   Dried krill eyeballs were obtained from Euphausia superba and Euphausia pacifica by using a patented industry method and their chemical compositions were examined. Crude protein content was 77.7% and 80.8% of the dry matter of E. superba and E. pacifica , respectively. The dominating amino acids in both krill were glutamic acid, aspartic acid, glycine, arginine, leucine and tyrosine. Crude fat content was 10.9% and 5.4% of dry matter of E. superba and E. pacifica , respectively. The main lipid class of the extracted lipids was phospholipids at 88.5% in E. superba and 96.4% in E. pacifica . The dominating fatty acids in both krill were 22:6 ( n- 3), 20:5 ( n- 3), 16:0 and 18:1 ( n- 9). Astaxanthin (3, 3'-dihydroxy-β, β-carotene-4, 4'-dione) content of E. superba and E. pacifica was 566 mg/100 g and 252 mg/100 g of dry matter, respectively. Retinol of E. superba and E. pacifica was 153.0 mg/100 g (510 000 IU/100 g) and 57.6 mg/100 g (192 000 IU/100 g) of dry matter, respectively. The lipophilic extract of E. superba by using n -hexane contained 1923 mg/100 g of astaxanthin at approximately four times higher than the dried eyeballs.     

Analysis of retinol, 3‐hydroxyretinol and 3,4‐didehydroretinol in North American farm‐raised freshwater fish liver,muscle and feed

Vitamin A (VA) is an essential micronutrient in fish, vital for reproduction, vision and immunity. Freshwater fish species store and use VA in the form of retinol (ROL), as well as uncommon forms such as 3,4‐didehydroretinol (DROL) and 3‐hydroxyretinol (3ROL). We developed and validated an HPLC method capable of measuring ROL, DROL and 3ROL in the feed and tissues of North American freshwater fish, for which little information on retinoid concentrations is available. DROL and ROL were higher than expected in both fish feed and fish liver (at 9.5–29.6 mg kg^?1 DROL and 26.9–79.2 mg kg^?1 ROL for feed; and 19.8–548.8 μg g^?1 DROL and 10.4–128.8 μg g^?1 ROL for liver). Interestingly, DROL concentrations were lower than ROL in fish feed, but often substantially higher in fish liver. Concentrations of ROL and DROL were similar to each other in muscle. 3ROL was detected in fish liver only. To our knowledge, this is the first publication to measure DROL concentrations in North American farm‐raised fish and commercial fish feed. Monitoring of not only ROL, but DROL and 3ROL as well, may be advisable to better assess the VA content of fish feed and tissue.     

β-carotene and retinol contents in the meat of herbivorous ungulates with a special reference to their public health importance

The aim of this study was to estimate total carotenoids, β-carotene and retinol concentrations in the liversand muscles of some ungulates (cattle, buffalo, sheep, goats and horses) in comparison with the Wistar rats asa control. Cattle and horses had the highest contents of total carotenoids and β-carotene. Unexpectedly, sheepwas the highest accumulator of retinol with a mean concentration of 203 ± 23.34 µg/g, whilethe least accumulator was buffalo, having a mean value of 58.28 ± 13.77 µg/g. Livers hadhigher contents of the examined phytochemicals than muscles. Consumption of these tissues may provide humanwith some needs from these important phytochemicals, though ingestion of livers, especially that of the sheep,is not advisable for the pregnant women.     

小尾寒羊高繁殖力候选基因RBP4的研究

以视黄醇结合蛋白4（retinol binding protein 4，RBP4）基因为候选基因，采用PCR-SSCP技术分析了RBP4基因在高繁殖力绵羊品种（小尾寒羊、湖羊）以及低繁殖力绵羊品种（多赛特羊、萨福克羊）中的单核苷酸多态性，同时研究这个基因对小尾寒羊高繁殖力的影响。结果表明：RBP4基因扩增片段在4个绵羊品种中存在PCR-SSCP多态性。BB基因型只出现在高繁殖力绵羊品种中，而低繁殖力绵羊品种则没有BB基因型；AB基因型频率随着绵羊繁殖力的降低而升高；AA基因型只出现在小尾寒羊、多赛特羊中。BB基因型小尾寒羊产羔数分别比AA和AB基因型多0．52只（Pd0．05）和0．67只（Pd0．05），AA和AB基因型小尾寒羊产羔数没有显著差异（P〉0．05）。本研究检测的绵羊RBP4基因座位与小尾寒羊高繁殖力相关。