小麦钙调素新亚型TaCaM5的克隆及表达分析

利用RT-PCR技术,从条锈菌诱导的小麦叶片中分离出一个编码CaM基因的cDNA序列, 经氨基酸序列分析确定其为一个新的小麦CaM亚型,暂被命名为TaCaM5。TaCaM5包含一个完整450 bp的开放阅读框,编码149个氨基酸;编码的蛋白不含跨膜区、无信号肽、定位在胞内,具有4个EF-hand保守结构域。在目前已知的CaM基因中,TaCaM5与玉米CaM基因的亲缘关系最近,相似性高达97%。该基因在根、茎、叶等组织中均有不同程度的表达;并且受条锈菌诱导表达,在非亲和组合与亲和组合中,分别在接种后6 h和24 h表达量最高。外源植物激素脱落酸、茉莉酸甲酯和乙烯诱导TaCaM5上调表达,水杨酸诱导其下调表达。TaCaM5在机械伤害、干旱和低温条件下表达量上升,在高盐环境下表达量降低。表明TaCaM5可能通过茉莉酸和乙烯等信号途径参与小麦对条锈菌的防御反应,同时参与机械伤害、低温和干旱环境下的Ca²⁺-CaM信号转导途径。     

Identification of the SP22 Sperm Protein in Santa Inês and Dorper Rams

The sperm membrane protein referred to as SP22 has been identified in different species and, at least in rats, is highly correlated with fertility. The goals of this study were to identify and to quantify the SP22 protein on spermatozoa from adult rams (Dorper and Santa Inês breeds), and to correlate its levels to morphological and kinematics parameters. SP22 on ram sperm was effectively quantified by both enzyme‐linked immunosorbent assay (ELISA) and fluorescein isothiocyanate immunostaining analysis and the two methods were significantly correlated (R² = 0.70). Clustering analysis of motility parameters obtained by computer‐assisted semen analysis system was used to establish that three distinct kinematic subpopulations with different vigour and progressiveness coexistent within ejaculate. While there were significant differences in the distribution of the three subpopulations in the rams, there was no significant correlation between the proportion of each subpopulation in the rams and the SP22 levels. Quantification of SP22 immunostaining intensity was not correlated with any of the sperm parameters. However, SP22 levels obtained by ELISA were negatively correlated with morphological abnormalities and positively correlated with membrane integrity (three variable R² = 0.47). Future breeding studies are now needed to validate that this protein is a biomarker of fertility in this species.     

High Periconceptional Protein Intake Modifies Uterine and Embryonic Relationships Increasing Early Pregnancy Losses and Embryo Growth Retardation in Sheep

The effects of supplemented protein level (PL) during the periconceptional period and their interaction with body condition were evaluated in sheep. Multiparous Rambouillet ewes (n = 12) received two PL of rumen undegradable protein (UIP) during a 30‐day pre‐mating and 15‐day post‐mating period: low [LPL, 24% crude protein (CP), 14 g UIP and 36 g/CP animal/day] and high [HPL, 44% CP, 30 g UIP and 50 g/CP animal/day]. While ovulation rate (OR) did not differ between treatments (1.6 ± 0.5, mean ± SEM), a lower fertility rate, a decreased embryo number and a reduced uterine pH (UpH) was observed in the HPL group (p < 0.05), irrespective of BC. Luteal tissue weight, volume and progesterone secretion did not differ among treatments. Sheep with lower UpH also had lower conceptus weight (Cwt; p < 0.05, r = 0.65) and conceptuses with lower mass tended to secrete less INF‐τ and IGF‐1, and the correspondent endometrial explants had a higher basal PGF_2α release. Current study indicates that high protein diets during the periconceptional period in sheep modify uterine and embryonic relationships, increasing early pregnancy losses and inducing embryo growth retardation. Surviving embryos were affected by weight reductions, which could compromise later foetal growth and birth weight. Results evidence the key role of a balanced diet in reproductive success and indicate that the quality and nutrient composition of the maternal diet are essential for an adequate establishment of pregnancy, having paramount effects on the interplay of the embryo and the uterus.     

Relationships between puppy management practices and reported measures of success in guide dog training

This study surveyed international guide dog organizations to compare their success rates with management practices. A questionnaire designed to identify the factors associated with international guide dog success was piloted with the cooperation of Guide Dogs NSW/ACT. The International Guide Dog Federation endorsed the study before the questionnaire was sent to 76 of its member organizations from 27 countries. There were 38 responses (of which 36 were usable) from guide dog organizations in 15 countries (50% response rate). Guide dog success rates were defined by the dogs' graduating success (the proportion of dogs commencing the program that successfully graduated as guide dogs) as well as working success (the proportion of dogs commencing the program that were working 1 year later). Working success and graduating success were found to be significantly different. Working success was considered the more informative estimate of true success, as it incorporated more variables than did graduating success.Quotas were used by many organizations to ensure that dogs graduated in sufficient numbers to meet the demand from visually impaired clientele. Despite our hypothesis that quotas would artificially inflate graduating success rates, logistic regression found that they were not associated with differences in graduating success rates, but that they were associated with greater working success. This finding indicates that quotas are not set at unrealistic levels and may help improve long-term success rates. Logistic regression also showed that dog breeds, the application of different temperament tests, the use of external breeders (as opposed to the organization breeding their own dogs), and the methods used to acquire information about the dogs during the puppy-raising period were significantly associated with these outcomes.     

A comparison of endoscopic and surgical collection procedures for the analysis of the bacterial flora in duodenal fluid from cats

In order to assess an endoscopic collection procedure, populations of bacteria in duodenal fluid from seven adult cats were compared in paired samples obtained by endoscopy and direct needle aspiration during laparotomy. Each sample of duodenal juice was subjected to quantitative and qualitative culture of bacteria under both aerobic and anaerobic conditions. There were no significant differences in total numbers or individual species of bacteria comparing the two collection procedures. These findings indicate that collection of duodenal juice by endoscopy using the procedure described provides a representative sample of small bowel fluid for the assessment of the bacterial flora. Therefore, there appears to be no need for more invasive or complicated sampling techniques when quantitative and qualitative culture of duodenal juice is indicated as part of an investigation of small bowel disease in cats.     

Effect of nitrogen species supply and mycorrhizal colonization on organosulfur and phenolic compounds in onions

The aim of the present study was to test whether variations in the root environment affect the content of health-related organosulfur compounds, total phenolic compounds, and flavonol glycoside concentrations in onions. For this purpose, greenhouse-grown onions ( Allium cepa L.) were either inoculated with a commercial arbuscular mycorrhizal inoculum or a sterile inoculum and were provided with two NH(4)(+):NO(3)(-) ratios as a nitrogen source. Onion growth, arbuscular mycorrhizal colonization rate, sugars, and nutrient element concentrations were also quantified. The plant antioxidant activity and quercetin monoglucoside and organosulfur compound concentrations increased with dominant nitrate supply. Furthermore, mycorrhizal colonization increased the antioxidant activity and also concentrations of the major quercetin glucosides. The present study provides clear evidence that antioxidant activity, quercetin glycosides, and organosulfur compounds can be increased in sufficiently supplied onion plants by dominant nitrate supply or application of arbuscular mycorrhizal fungi. This was probably due to increased precursor production and induced defense mechanisms.     

Effects of thyroxine administration on the growth and survival of pike silverside (Chirostoma estor) juveniles

The pike silverside has high aquaculture potential despite its slow growth. In this study, thyroxine (T₄) concentrations (0.13, 1.3 and 13 nM), a control with no hormonal supplement and a negative control containing 4.5 mM methimazole (MMI) were tested to evaluate the growth of this species. Juveniles (0.2 g) were exposed by immersion to these treatments for 8 h every second day for 120 days, and growth evaluations were performed monthly over the entire trial period. In addition, tissue samples from each treatment group were assayed for triiodothyronine (T₃) and deiodinase type 2 (D2) activity . The survival rates in all T₄ groups were high, and a significant increase in growth was observed (average of 58%). The MMI treatment caused an increase in mortality and a reduction in the final body weight compared with the control. T₄ administration did not affect the tissue levels of T₃, and it decreased muscular D2 activity only after 30 days of exposure. These results demonstrated that low concentrations of T₄ in the culture environment could improve the growth of this species without affecting tissue hormone levels. The technique may have useful applications for early‐stage aquaculture of this and other economically important species.     

Bovine asymmetric hind limb paresis, a presumptive in-utero plant poisoning

Summary: A new locomotory disturbance of cattle is described. The condition has occurred sporadically since the mid-1980s. Affected herds had all grazed flood plain pastures in a restricted area of north-western New South Wales. Calves were either born with clinical signs or developed them by 4 months of age. The disease was characterised by a slowly progressive, irreversible, asymmetrical, paresis of the hind limbs. Affected cattle experienced persistent hyper-extension of the hip and stifle joints. Macroscopic and microscopic examination of the nervous and musculoskeletal systems failed to demonstrate abnormalities that would account for the clinical signs. The disorder shares many similarities with bovine spastic paresis. It is suggested that the pathogenesis of the disorder is nervous, and probably involves nigro-striatal, medulla oblongata, and spinal dysfunctional inputs. An in-utero plant poisoning was suspected but no specific plant association was determined.