Optimizing injection time of GFP plasmid into sheep zygote

Microinjection of exogenous DNA into the cytoplasm of matured oocytes or zygotes is a promising technique to generate transgenic animals. However, the data about the microinjection time and procedure in sheep are limited and have not treated in detail. To obtain more in-depth information, the Sarda sheep oocytes from abattoir-derived ovaries were subjected to IVM and IVF. Then, the GFP plasmid as a reporter gene was injected into the cytoplasm of MII oocytes (n: 95) and zygotes at different post-insemination intervals (6–8 hpi, n: 120; 8–10 hpi, n: 122; 10–12 hpi, n: 110 and 12–14 hpi, n: 96). There were no significant differences in the cleavage rates between the groups. However, blastocyst rate of injected zygotes at all-time intervals was significantly lower than injected MII oocytes and control group (p < 0.05). Interestingly, the proportion of GFP-positive embryos was higher at 8–10 hpi compared with other injected groups (4 % versus 0 %, p  < 0.01). Among these, the proportion of mosaic embryos was high and two of those embryos developed to the blastocyst stage. In conclusion, we settled on the cytoplasmic microinjection of GFP plasmid at 8–10 hpi as an optimized time point for the production of transgenic sheep and subsequent experiments.     

Effects of pyriproxyfen, a juvenile hormone analog, on development of the mealworm, Tenebrio molitor

Pyriproxyfen, an analog of the juvenile hormone (JH) in insects, has been evaluated in vivo and in vitro on an important stored product pest, the mealworm Tenebrio molitor. On newly ecdysed pupae, this insect growth regulator (IGR) was applied topically (at 0.10 and 0.20 μg/insect). Enzyme immunoassay measurements showed a decrease of the ecdysteroid titer in the hemolymph of treated specimens. In addition, the treatment induced an increase of the protein concentration in the hemolymph, however, there was no significant effect on the protein band pattern. Using in vitro pupal integument explant cultures, pyriproxyfen (at 1 and 10 μM in the medium) caused a significant inhibition of ecdysteroid amounts and of the thickness of new cuticle secreted. These new results are discussed in relation to the physiology of this IGR with a JH action.     

Warts in the evolution of angiosperm wood

Summary The occurrence and distribution of the warty layer in twelve species of hardwoods have been investigated by transmission and/or scanning electron microscopy. Samples were selected on the common feature of reportedly having both primitive vessel types with scalariform perforation plates and more evolutionarily advanced vessel types with simple plates. Among the six angiosperm families represented, warts were generally found in the more primitive-type vessel elements. The more advanced vessel types rarely displayed a warty layer. Warts were also sparse or absent in other specialized cells, the fiber tracheids and libriform fibers. From the evidence presented here and in the literature, the variable presence and morphology of the warty layer in hardwoods (or for wood in general) appears to be attributable to a phylogenetic trend. According to this trend, conifer tracheids and primitive hardwood cells are nearly always warted, but as the cell type becomes more advanced or specialized, it becomes increasingly wart-free.     

Modelling Biomass Accumulation and Partitioning in Chickpea (Cicer arietinum L.)

Quantitative information regarding biomass accumulation and partitioning in chickpea (Cicer arietinum L.) is limited or inconclusive. The objective of this study was to obtain baseline values for extinction coefficient (K_S), radiation use efficiency (RUE, g MJ^?1) and biomass partitioning coefficients of chickpea crops grown under well‐watered conditions. The stability of these parameters during the crop life cycle and under different environmental and growth conditions, caused by season and sowing date and density, were also evaluated. Two field experiments, each with three sowing dates and four plant densities, were conducted during 2002–2004. Crop leaf area index, light interception and crop biomass were measured between emergence and maturity. A K_S value of 0.5 was obtained. An average RUE of 1 g MJ^?1 was obtained. Plant density had no effect on RUE, but some effects of temperature were detected. There was no effect of solar radiation or vapour pressure deficit on RUE when RUE values were corrected for the effect of temperature. RUE was constant during the whole crop cycle. A biphasic pattern was found for biomass partitioning between leaves and stems before first‐seed stage. At lower levels of total dry matter, 54 % of biomass produced was allocated to leaves, but at higher levels of total dry matter, i.e. under favourable and prolonged conditions for vegetative growth, this portion decreased to 28 %. During the period from first‐pod to first‐seed, 60 % of biomass produced went to stems, 27 % to pods and 13 % to leaves. During the period from first‐seed to maturity, 83 % of biomass was partitioned to pods. It was concluded that using fixed partitioning coefficients after first‐seed are not as effective as they are before this stage. Environmental conditions (temperature and solar radiation) and plant density did not affect partitioning of biomass.     

Isolation of Cache Valley virus and detection of antibody for selected arboviruses in Michigan horses in 1980

Blood samples collected in September and November 1980 from 87 horses in southwestern Michigan were examined for virus isolation and for plaque-reduction neutralizing antibody against selected arboviruses. Cache Valley virus was isolated from the blood of a clinically normal horse in St Joseph County in September. The age-specific antibody prevalence for Cache Valley virus indicated enzootic transmission in the study area. The high antibody prevalence and the lack of age-specific antibody prevalence indicated sporadic, but intense, exposure to Jamestown Canyon virus. Low prevalences of antibody were detected for Highlands J, snowshoe hare, St Louis encephalitis, and trivittatus viruses.     

Spatial variability of soil microbial indices in common alder COMMON ALDER(Alnus glutinosa) stands using a geostatistical approach in northern Iran

Microbial indices and their spatial patterns are strongly affected by environmental factors. Spatial variability of soil properties is one of the most important causes of variability in soil microbial indices. This research was conducted in the Caspian forest to assess spatial variabilities and frequency distributions of microbial properties.Ninety soil samples were taken using a grid sampling design 40 9 40 m. Microbial indices, organic carbon,nitrogen and pH were determined. Soil variable distributions showed that microbial indices had abnormal distributions. Logarithmic transformation produced normal distribution. Spatial continuity using geostatistical(variogram) was studied and maps obtained by point kriging.The variograms revealed the presence of spatial autocorrelation. The results indicate that spatial dependence of soil microbial indices was affected by non-intrinsic factors and forest management procedures. The maps show that soil microbial indices and soil properties have spatial variability. The spatial pattern of microbial indices was correlated to organic carbon and nitrogen.     

Effect of age,sex, and season on the prevalence of Linguatula serrata infestation in mesenteric lymph nodes of goats slaughtered in Tabriz,Iran

Tropical Animal Health and Production - This research was conducted to determine the prevalence and intensity of infection with nymphs of Linguatula serrata in mesenteric lymph nodes of the goats...     

Dietary zinc requirement of Siberian sturgeon (Acipenser baerii,Brandt 1869) juveniles,based on the growth performance and blood parameters

International Aquatic Research - This study investigated the effect of dietary Zn levels on growth performance, feed utilization, and hematological parameters of juvenile Siberian sturgeon...