水稻丝氨酸蛋白酶S8基因家族的分布及分析

水稻丝氨酸蛋白酶S8基因家族在水稻的生长发育过程中起着重要的调控作用。本研究利用公共数据库资源,分析水稻中丝氨酸蛋白酶S8基因家族,在水稻12条染色体上找到46个该类基因。通过其结构分析发现,每个基因的内含子数目从0到10各不相同,但氨基酸序列是非常保守的,都有催化活性位点和底物结合位点。系统进化树分析显示,这46个基因分为3个亚家族,S8-1亚家族最大。该家族基因的进化主要是通过基因重复复制的方式进行,其表达模式发生了变化,并且多个基因在穗部具有表达。     

ELASTOGRAPHY OF THE NORMAL CANINE LIVER,SPLEEN AND KIDNEYS

Elastography is a simple, expedient and noninvasive technique that may be used to assess the elasticity or stiffness of a tissue, in conjunction with traditional B‐mode ultrasonography. Quantitative assessment of tissue stiffness can be made which involves measurement of the shear wave velocity within the tissue of interest. The goal of this study was to assess the feasibility of elastography for clinical use in the abdomen of conscious small animals and to investigate factors that affect shear wave velocity measurement. Elastography was performed on the liver, spleen, and kidneys of 15 dogs at predefined depths within the parenchyma. Breed, age, gender, neuter status, and weight were documented for each animal. Depth at which measurements were taken had a significant negative relationship with the shear wave velocity value obtained. Individual dog effects, such as weight and gender, also appeared to have a significant effect on the shear wave velocity measurement for specific organs; weight had a significant positive effect on the shear wave velocity for each of the organs examined, whereas the effect of gender was inconsistent between organs (having a positive effect for the liver and a negative effect for the spleen). It is hoped that these results may act as a baseline to guide further work into the field of elastography in companion animals.     

In vitro production of porcine zygotes using intracytoplasmic injection of vitrified sperm

The objectives of this study were to evaluate if vitrified porcine spermatozoa are able to maintain their capacity to produce zygotes in vitro using intracytoplasmic sperm injection (ICSI) and to evaluate the zygote development in two in vitro atmospheric conditions: 5% CO₂ and tri‐gas. A group of porcine oocytes maturated in vitro were injected with vitrified‐warmed sperm (treatment group) and another group, with sperm diluted and conserved at 17°C (control group). To evidence parthenogenetic activation, some oocytes were submitted to a Sham test. The injected oocytes were cultured in G1 medium at 38°C, 100% humidity and 5% CO₂ or tri‐gas. No significant differences (p > .05) were observed in embryo development between the oocytes injected with vitrified‐warmed sperm (31.8%; 36/113), and those injected with semen diluted and conserved at 17°C (35.5%; 32/90), when cultured in 5% CO₂ or under tri‐gas atmosphere (42.9%; 39/91 vs. 34.2%; 26/76, respectively). No significant differences (p > .05) were observed in the percentage of pronuclei (PN) obtained between 5% CO₂ and tri‐gas, within each treatment either. Of the 52 oocytes submitted to the Sham test, only two presented a female PN (activation) indicating that the PN observed in the treatment group were a product of fertilization and not parthenogenetic activation. To conclude, porcine sperm vitrified using spheres, at a concentration of 5 × 10⁶ spermatozoa/ml in TALP medium with 1% bovine serum albumin (BSA), conserve condensed and intact chromatin capable of producing early embryo development up to the pronuclear stage.     

Methods of detection of Chlamydia psittaci in domesticated and wild birds

OBJECTIVE: To study the occurrence of Chlamydia psittaci in domesticated and wild birds and compare the sensitivity of molecular detection with cell culture isolation. DESIGN: Study of cell culture isolation and PCR detection of C psittaci in avian samples. PROCEDURE: Samples were obtained from 485 birds. Domesticated birds were selected at random from pet shops, private aviaries and zoos, while wild birds were captured locally, sampled, and immediately released. Swabs were collected from choanal slit, conjunctiva and cloaca of each bird and pooled. Samples were divided into equal portions for use in PCR dot-blot and cell culture detection. PCR and dot-blot detection was based on the ompB gene. RESULTS: Prevalence of infection varied markedly between flocks of captive birds. It was highest where there were frequent changes in the flock members or where there were many birds confined in small areas. C psittaci was not detected in wild birds or water birds. The sensitivity of cell culture compared to PCR dot-blot detection was 68%. All samples positive by cell culture were also positive by PCR. CONCLUSIONS: PCR-dot blot detection of C psittaci in birds appears to be more sensitive than cell culture isolation in this study. C psittaci infection of birds may occur in clinically normal captive birds.     

Reproductive and Metabolic Responses of Early‐lactating Dairy Cows Fed Different Dietary Protein Sources

Optimal reproduction is very closely tied with optimal nutrition, and early‐lactation diets in cows are critical to successful reproduction and monitoring is important. To evaluate the effects of different dietary protein sources on metabolic parameters and reproductive activity, a total of 36 Italian Friesian early‐lactating dairy cows were assigned for 16 weeks to three dietary treatments as follow: the control diet contained soya bean meal (SBM) as the main protein source, whereas the experimental diets contained faba bean (FB) or pea seeds (PS) as alternative protein sources. Diets were formulated to be isocaloric and isonitrogenous. Cow blood samples were collected, and plasma were analysed for metabolites, biological enzymes, β‐hydroxybutyrate (BHBA) and non‐esterified fatty acids (NEFA). Feeding alternative protein sources had no effects on most metabolic blood profile, except for blood cholesterol, triglycerides and urea. Results from reproductive parameters indicated that cows fed FB diet had a lower insemination index, but a shorter calving to conception period and an improved conception rate and artificial insemination outcome, when compared to cows fed SBM or PS diets. It can be concluded that replacing conventional dietary SBM with alternative protein sources, especially FB, resulted in improved reproductive performances and metabolic parameters in early‐lactating dairy cows.