Effect of Artemia enrichment on the growth and survival of Pacific bluefin tuna Thunnus orientalis (Temminck & Schlegel) larvae

This study was carried out to investigate the suitability of Artemia enriched with docosahexaenoic acid (DHA) and choline as live food on the growth and survival rate of the Pacific bluefin tuna (PBT; Thunnus orientalis) larvae. The PBT larvae were fed either Artemia enriched with oleic acid (Diet 1), DHA (Diet 2), DHA+choline 1.0 mg L^?1 (Diet 3) and DHA+choline 2.0 mg L^?1 (Diet 4) or striped knifejaw larvae (Diet 5, reference diet), in duplicate for 12 days. Enrichment of Artemia with DHA significantly increased the DHA levels to 13.9, 13.8 and 12.5 mg g^?1 on a dry matter basis in Diets 2, 3 and 4 respectively; however, the levels were significantly lower than the reference diet (26.9 mg g^?1 dry matter basis; Diet 5). Although growth and survival rate were significantly improved by the enrichment of Artemia with DHA and choline, the improvement was negligible compared with the enhanced growth and survival rate of the fish larvae‐fed group (P<0.05). The results demonstrated that enriched Artemia does not seem to be the right choice to feed the PBT larvae perhaps because of the difficulties in achieving the correct balance of fatty acid with higher DHA/EPA from Artemia nauplii.     

断奶仔猪ACE2基因的克隆及遗传进化分析

采用RT-PCR扩增和基因克隆技术鉴定断奶仔猪血管紧张素转化酶2(ACE2)基因序列,并与公布的猪以及其他物种的ACE2基因进行同源性比对.结果,成功克隆出了仔猪ACE2部分序列,该核苷酸序列与GenBank上公布的野猪ACE2核苷酸序列同源性达到98％,与欧洲牛的同源性为87.8％,与人的同源性为78.8％,与禽类(鸡)的同源性较低.遗传进化分析发现该扩增片段与牛的遗传距离最近,与鸡则处在完全不同的2个分枝上.氨基酸进化与基因遗传进化结果一致.本研究为仔猪ACE2的有效表达、生物学活性及其在苏姜猪中作用的研究奠定基础.     

Effect of altering the steric hindrance of the nitrogen atom in 2,5-bis(pyridin-n-yl)-1,3,4 thiadiazole isomers on their ability to elicit tomato defense responses against Verticillium wilt and crown gall diseases

Three isomers of the ligand 2,5-bis(pyridinyl)-1,3,4-thiadiazole, with the N atom of pyridine group in position 2, 3 or 4, named respectively, L2, L3 and L4 were compared for their use as plant defense activators. They were examined for their ability to protect tomato plants from Verticillium dahliae and Agrobacterium tumefaciens in the greenhouse, to induce reactive oxygen species and to activate plant defenses, including antioxidant enzymes. The three ligand isomers exhibited in vitro only slight inhibition of radial growth of V. dahliae, while no significant inhibition was observed for phytopathogenic bacteria. In the greenhouse, the three ligand isomers statistically reduced the severity of Verticillium wilt and crown gall on tomato plants, and the isomers L3 and L4 were the most efficient to control Verticillium wilt. This superiority was reflected in their differential ability to activate H₂O₂ accumulation, antioxidant enzymes including catalase and ascorbate peroxidase and other defense-related enzymes such as guaiacol peroxidase and polyphenol oxidase. These results demonstrated that the presence of the N atom within the two pyridinyl groups in the position 3 or 4 highly enhanced the activity of plant defense and antioxidant responses as well as their ability to reduce the severity of symptoms caused by V. dahliae on tomato.     

Response of plant yield and leaf pigments to saline conditions: Effectiveness of different rootstocks in melon plants (Cucumis melo L.)

Two varieties of Cucumis melo (Resisto and Arava) were grafted onto three hybrids of Cucurbita maxima and Cucurbita moschata cultivars (Shintoza, RS-841 and Kamel). Ungrafted Cucumis melo var. Resisto and var. Arava plants were used as controls. Plants were grown under controlled greenhouse conditions and were constantly fertilized with macro- and micronutrients, supplied with irrigation water rich in Na⁺ and Cl^- Contents of chlorophylls a and b, carotene pigments, Cl^- and total and soluble Na⁺ and K⁺ ions were measured in all the scion parts of the plants. The results showed that grafted plants exhibited differences in the leaf content of Na+ and especially Cl^- in comparison with ungrafted plants. In addition, yield as well as leaf pigments appeared to be good indicators of Cl^- levels in scion parts. It is assumed that grafted plants developed various mechanisms to avoid physiological damage caused by the excessive accumulation of these ions in leaf, including the exclusion of Cl^- ion and/or decrease in Cl^- absorption by the roots and the replacement or substitution of total K⁺ by total Na⁺ in the foliar parts.     

Efficacy of topically applied liposome-bound tetracycline in the treatment of dry eye model

Objective To evaluate the effects of liposome‐bound tetracycline eye drops in a rabbit dry eye model evaluating their advantage of being less allergic, preservative free and prolonged action compared with other tear substitutes. Procedures New Zealand albino rabbits were equally divided into control group and dry eye induced groups. Dryness was induced in 24 eyes of 12 healthy adult male albino rabbits by instilling atropine sulfate eye drops 1% three times daily for 1 week, then animals were subdivided into four groups; group 1 (rabbits with dry eye model), groups 2, 3, and 4: rabbits with dry eye model treated for 7 days starting on 7th day of dryness induction with either tetracycline, empty liposome, or combined tetracycline with liposome as topical eye drops respectively. Schirmer (STT) test and tear break up time (TBUT) were assessed on days 0, 2, 4, 7, 9, 11, and 14. Animals were sacrificed on day 14 and histopathological examination of the cornea and conjunctiva was performed. Results Tear break up time and STT test values were significantly improved in groups 2, 3, 4 as compared with group 1. The histopathological examination showed normal cytoarchitecture of corneas and conjunctivae in groups 2, 3, 4 against the dryness effect that continued to affect the cornea and conjunctival epithelium in group 1. There was a significant improvement in the group treated with liposome‐bound tetracycline eye drops (group 4) as compared with tetracycline alone (group 2) and empty liposome (group 3). Conclusion The use of liposome encapsulated tetracycline significantly improved STT and TBUT values as well as reverse surface ocular pathology.     

Molecular cloning and expression profiling of procollagen α1 (I) of cultured Pacific bluefin tuna

Type I collagen is widely distributed in most organs in teleosts. It plays a role not only in intercellular adhesion, but also in molecular signaling. In this study, Pacific bluefin tuna (PBT) procollagen α1 (I) cDNA was cloned and characterized. The nine fragments of a procollagen α1 (I) chain cDNA clone were prepared and spliced together to create the complete coding region. The resulting amino acid sequence was homologous with that of other teleosts. The mRNA expression profile of PBT procollagen α1 (I) in various tissues and the phylogenetic analysis with other vertebrate procollagen α1 (I) chains suggest that PBT procollagen α1 (I) could be a precursor form of the PBT type I collagen α1 chain. In addition, its level of expression in PBT larvae and early juveniles gradually increased with somatic growth. This increase was related to the standard length, wet body weight, and protein content of each individual fish. Therefore, the expression profile of procollagen α1 (I) may be a useful indicator for somatic growth in fish larvae and juveniles.     

Ovarian hormones and antioxidant biomarkers in dromedary camels synchronized with new and re-used controlled intravaginal drug release (CIDR)/GPG (Ovsynch) program during breeding season

This study aimed to investigate the effect of CIDR, re-used wCIDR, and Ovsynch protocols for the synchronization of follicular waves on ovarian hormones, oxidative stress, and antioxidant biomarkers during the breeding season. Dromedary camels (N?=?18) were divided into three equal groups. The first group received CIDR. The second group received previously used wCIDR after thorough cleaning and disinfection. The third group was subjected to GPG protocol. Progesterone (P₄), estradiol (E2) l, total antioxidant capacity (TAC), catalase (CAT), lipid peroxide product (MDA), nitric oxide (NO), and glutathione reduced (GSH) were measured. Days during CIDR affected P4 (P?= 0.0001), E2 (P?= 0.047), TAC (P?= 0.01), NO (P?= 0.028), and GSH (P?= 0.005). Days during re-used wCIDR effected P4, TAC, CAT, NO, GSH, and MDA (P?≤ 0.001). Days during GPG effected P4, E2, TAC, GSH (P?= 0.0001), MDA (P?= 0.036), and NO (P?= 0.02). CIDR-treated camels had high P4 (P?= 0.0001), E2 (P?= 0.0001), TAC (P?= 0.012), and NO (P?= 0.0001), with low GSH (P?= 0.001), and MDA (P?= 0.003). Exogenous progesterone improved ovarian hormones and the antioxidant capacity and minimized the oxidative stress than the GPG treatment and is recommended for future reproductive management of camels.

     

Increase in NAD(P)H‐dependent generation of active oxygen species and changes in lipid composition of microsomes isolated from roots of zinc‐deficient bean plants

The role of zinc (Zn) in maintaining the structural and functional integrity of plant membranes was investigated in the present work. The relationship between the activity of NAD(P)H oxidases generating active oxygen species and changes in lipid composition and peroxidation was evaluated in microsomal membrane vesicles isolated from roots of Zn‐defícient bean (Phaseolus vulgaris L., cv. Bobis) plants. Zinc content of bean root microsomal membranes was decreased by about 30% by Zn deficiency. Microsomes isolated from roots of Zn‐deficient plants showed higher rates of NAD(P)H oxidation and NAD(P)H‐dependent O₂ ^‐ generation than Zn‐sufficient roots. Microsomal O₂ ^‐ consumption, measured in the presence of pyridine nucleotides, was also considerably enhanced by Zn deficiency. This latter activity was greatly stimulated by Fe(III)EDTA, while inhibited by Superoxide dismutase (SOD) and catalase, indicating that active oxygen species were produced during the oxygen consuming enzyme reaction. Zinc deficiency caused a decline in microsomal phospholipid (PL) content. In addition, saturated fatty acids were present at a higher proportion than unsaturated fatty acids in microsomes from Zn‐deficient roots. Sterol content of microsomal vesicles was also modified by Zn deficiency, which led to an increase in the planar sterol campesterol and a concomitant decrease in stigmasterol and sitosterol content. NADPH‐dependent lipid peroxidation, directly measured in microsomal vesicles as malondialdehyde (MDA) production, was slightly enhanced by Zn deficiency. These results support the idea that Zn deficiency determines an enhanced generation of harmful oxygen species by membrane‐associated enzymes and show that this activity can be more pronounced in the presence of iron (Fe), which accumulates in Zn‐deficient tissues. The relationship between the occurrence of this phenomenon and the changes in membrane lipid profile is discussed.