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1.
The objective of this study was to examine the effect of donor breed on pronuclear‐stage embryo yield to be used for DNA microinjection in a transgenesis goat program. Twelve Canindé and twelve Saanen goats were heat synchronized using a progestagen‐cloprostenol treatment. Forty‐eight hours before the sponge removal, superovulation was induced with a total administration of 4.4 mg/kg bodyweight NIH‐FSH‐P1, given twice daily in decreasing doses over 3 days. In addition, goats received 100 μg of GnRH and they were hand‐mated at 36 and 48 h after progestagen removal. Embryo recovery was performed by oviduct flushing at 72 h after sponge removal. Embryos were microinjected with a DNA construct and noticeable swelling of the nuclei was the criterion for successful microinjection. The total diameter, cytoplasm diameter, zona pellucida thickness and pronuclei diameter were measured for each microinjected embryo. A higher (p < 0.05) percentage of fertilized ova was observed in Canindé (89.9%) than Saanen (36.2%) goats. In addition, Canindé donors produced a higher percentage of pronuclear embryos when compared with Saanen: 72.5% vs 20.6% (p < 0.05), respectively. Successful microinjection was verified in 96.7% and 73.3% of times in Canindé and Saanen embryos, respectively (p < 0.05). Significant differences were observed for all morphometric parameters except for cytoplasm diameter. In conclusion, under our study experimental conditions, Canindé were more efficient than Saanen goats concerning the pronuclear embryo yield and manipulation. The use of Canindé goats in transgenesis programs could be increase the interest in their breeding and could be contribute to saving them from extinction.  相似文献   
2.
Sera collected from apparently healthy 6-12-month-old cats (n = 31) presented to the Society for the Prevention of Cruelty to Animals Veterinary Clinic in Bloemfontein for neutering were tested for antibodies reactive to Bartonella henselae (Houston-1 strain) by indirect fluorescent antibody testing. Whole blood collected from the cats was used in isolation experiments and subsequent identification of Bartonella species was based on comparison of the nucleotide base sequence of polymerase chain reaction-amplified citrate synthase gene fragments. While none of the cats had antibodies reactive with B. henselae at titres > or =1/64, an organism with a partial citrate synthase gene sequence identical to that of B. henselae (Houston-1) was isolated from 1 cat.  相似文献   
3.
The blood group antigen Dog Erythrocyte Antigen (DEA) 1.1 is clinically the most important canine blood group as DEA 1.1 antibodies are capable of causing acute haemolytic, potentially life-threatening transfusion reactions. Dogs do not have naturally occurring antibodies to DEA 1.1 but are rapidly sensitised by the first incompatible transfusion. The prevalence of DEA 1.1 in the general dog population is estimated at 42-46%. Canine blood donors registered with the Onderstepoort Animal Blood Bank (n = 93) as well as potential donors (n = 140) were typed for DEA 1.1 using a monoclonal antibody card kit. All dogs came from the Onderstepoort area, near Pretoria, Gauteng province, South Africa. Overall prevalence of DEA 1.1 was 47%. Prevalence was 47% in purebred dogs and 48% in mongrels. Distinct breed differences were noted with less than 20% of German shepherd dogs and Boxers and greater than 75% of Rottweilers, Great Danes, St Bernards and Dalmations testing DEA 1.1 positive. Knowledge of local breed differences will increase effectiveness of blood donor recruitment.  相似文献   
4.
Langdon durum D-genome disomic substitution lines were used to study the chromosome locations of adult-plant leaf rust resistance genes identified from tetraploid wheat accessions. The accessions are 104 (Triticum turgidum subsp. dicoccum var. arras) and 127 (T. turgidum subsp. durum var. aestivum). The complete sets of the substitution lines were crossed as female parents with the accessions and F1 double monosomic individuals selected at metaphase I. Segregating F2 individuals were inoculated during the flag leaf stage with pathotype UVPrt2 of Puccinia triticina. The substitution analysis involving accession 104 showed that the gene for leaf rust resistance is located on chromosome 6B. The analysis with accession 127 indicated that chromosome 4A carries a gene for leaf rust resistance. The two novel genes are temporarily designated as Lrac104 and Lrac127, respectively from accessions 104 and 127.  相似文献   
5.
This article applies Bayesian nonparametric techniques of analysis to the mixed linear model. The distribution of the random effects is specific as a nonparametric prior. A Dirichlet process prior is specified on the space of prior distributions. A modified Dirichlet process is described and applied using a Gibbs sampler. The approach is demonstrated in an investigation of the changes over time of packed cell volume in two breeds of cattle.  相似文献   
6.
Three hundred and fifty three Triticum accessions, several also classified as Aegilops and comprising 13 diploid, tetraploid or hexaploid species, were screened for seedling and adult-plant resistance to Puccinia triticina Eriks. using a mixture of pathotypes UVPrt2, 3, 9 and 13. Seedlings were spray-inoculated with a suspension of freshly collected urediospores in distilled water containing Tween 20® seven days after planting. Infection types (ITs) were scored 10 days post-inoculation (d.p.i.). Fully expanded flag leaves were inoculated and ITs and leaf rust severity were scored 16 d.p.i. One hundred and eighty two of the accessions were resistant to moderately resistant in the adult stage, whereas 126 were resistant or moderately resistant as seedlings to the pathotype mixture. Hypersensitive adult-plant resistance was particularly apparent in lines of T. timopheevii, T. sharonense, T. longissimum, T. searsii and T. turgidum. In T. turgidum, which comprised 272 accessions, approximately 44% of the adult plants were resistant to moderately resistant compared to 28% of the seedlings. The expression of these adult-plant resistances varied between hypersensitive flecking of flag leaves, and small pustules commonly associated with chlorosis and/or necrosis of leaf tissue. Partial resistance, expressed by small pustules without any apparent chlorosis, was observed in species such as T. tauschii, T. turgidum ssp. durum and T. turgidum ssp. pyramidale.  相似文献   
7.
Juice of the Sclerocarya birrea subsp. caffra (marula) fruit was fermented by indigenous microflora and different commercial Saccharomyces cerevisiae yeast strains at different temperatures, namely, 15 and 30 degrees C. Volatile acids, esters, and higher alcohols were quantified in the wine and distillates, and the results were interpreted using a multivariate analysis of variance and an average linkage cluster analysis. Significant differences between 15 and 30 degrees C and also among yeasts with respect to volatile compounds were observed. Yeast strains VIN7 and FC consistently produced wines and final distillates significantly different from the other strains. A panel of tasters and marula and brandy producers was asked to select wines and distillates that had an acceptable and typical marula "nose". They were also asked to detect the differences among wines and distillates fermented with the same yeast strain at different temperatures.  相似文献   
8.
The water sensitivity of soybeans was determined on a day-to-day basis from the onset of flowering to physiological maturity by correlating daily leaf water potential values of 50 different soil water regimes with corresponding grain, vegetative and biomass yields. Days, and consecutive days forming periods, during which significant negative correlations were obtained were regarded as water sensitive periods during the reproductive growth phase of the soybean crop.
Water deficits during flowering significantly inhibited vegetative and biomass production but inhibited grain yields only when occurring during early flowering. During pod elongation and seed development the sensitivity of the soybean plant to water stress was present but diminished in time with regard to vegetative and biomass yields. The effect on grain yields was restricted to pod elongation and to later seed development stages. Water stress affected grain yields to a far greater extent than vegetative growth during seed filling and physiological maturity.  相似文献   
9.
Unconditional quantum teleportation   总被引:5,自引:0,他引:5  
Quantum teleportation of optical coherent states was demonstrated experimentally using squeezed-state entanglement. The quantum nature of the achieved teleportation was verified by the experimentally determined fidelity Fexp = 0.58 +/- 0.02, which describes the match between input and output states. A fidelity greater than 0.5 is not possible for coherent states without the use of entanglement. This is the first realization of unconditional quantum teleportation where every state entering the device is actually teleported.  相似文献   
10.
Several Phytophthora spp. are known to cause a range of symptoms on citrus, resulting in significant crop losses worldwide. In South Africa, Phytophthora remains a destructive citrus disease, but the species and their distribution have not been well documented. A total of 162 Phytophthora isolates was collected from 60 citrus orchards in seven provinces of South Africa (Eastern Cape, Kwazulu-Natal, Limpopo, Mpumalanga, Northern Cape, North West and Western Cape). Isolates were identified to the species level through PCR-RFLP (restriction fragment length polymorphism) analyses of the internal transcribed spacer region. The identity of a subset of the isolates was confirmed using morphological and sequence analyses. Phytophthora nicotianae was the predominant species (76 % of isolates) and occurred in 80 % of the orchards in all of the provinces, followed by P. citrophthora (22 % of isolates in 28 % of orchards). The P. citrophthora isolates were further subdivided into two previously identified subgroups, G1 and G2, with most (69 %) of the isolates belonging to the G1 subgroup. Other Phytophthora species included P. multivora in the Western Cape Province, and an unknown species in the Eastern Cape Province with high sequence similarity (98 %) to a putative new species submitted to GenBank as Phytophthora taxon Sisuluriver. Phytophthora palmivora, a known citrus pathogen, was not identified. Most of the P. nicotianae isolates (79 %) were of the A1 mating type. The P. citrophthora isolates were mostly sterile (64 %), including most of the G1 isolates (81 %). The remaining G1 isolates (19 %) belonged to the A1 mating type, whereas almost all G2 isolates belonged to the A2 mating type except for one isolate that was sterile.  相似文献   
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