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1.
Effects of adding different concentrations of melatonin (10?7, 10?9 and 10?11 M) to maturation (Experiment 1; Control, IVM  + 10?7, IVM  + 10?9, IVM  + 10?11) and culture media (Experiment 2; Control, IVC  + 10?7, IVC  + 10?9, IVC  + 10?11) were evaluated on in vitro bovine embryonic development. The optimal concentration of melatonin (10?9 M) from Experiments 1–2 was tested in both maturation and/or culture media of Experiment 3 (Control, IVM  + 10?9, IVC  + 10?9, IVM /IVC  + 10?9). In Experiment 1, maturated oocytes from Control and IVM  + 10?9 treatments showed increased glutathione content, mitochondrial membrane potential and percentage of Grade I blastocysts (40.6% and 43%, respectively). In Experiment 2, an increase in the percentage of Grade I blastocysts was detected in IVC  + 10?7 (43.5%; 56.7%) and IVC  + 10?9 (47.4%; 57.4%). Moreover, a lower number and percentage of apoptotic cells in blastocysts were observed in the IVC  + 10?9 group compared to Control (3.8 ± 0.6; 3.6% versus 6.1 ± 0.6; 5.3%). In Experiment 3, the IVC  + 10?9 treatment increased percentage of Grade I blastocysts with a lower number of apoptotic cells compared to IVM /IVC  + 10?9 group (52.6%; 3.0 ± 0.5 versus 46.0%; 5.4 ± 1.0). The IVC  + 10?9 treatment also had a higher mRNA expression of antioxidant gene (SOD 2) compared to the Control, as well as the heat shock protein (HSPB 1) compared to the IVM  + 10?9. Reactive oxygen species production was greater in the IVM /IVC  + 10?9 treatment group. In conclusion, the 10?9 M concentration of melatonin and the in vitro production phase in which it is used directly affected embryonic development and quality.  相似文献   
2.
A whole genome scan to map quantitative trait loci (QTL) for persistency of milk yield (PMY), persistency of fat yield (PFY), persistency of protein yield (PPY) and persistency of milk energy yield (PEY) was performed in a granddaughter design in the German Holstein dairy cattle population. The analysis included 16 paternal half‐sib families with a total of 872 bulls. The analysis was carried out for the first lactation and for the first three lactations combined using univariate weighted multimarker regression. Controlling the false discovery rate across traits and data sets at a level of 0.15 and treating the four persistency traits as different traits revealed 27 significant QTL. A total of 12 chromosomes showed significant QTL effects on a chromosomewise basis. The DGAT1 effect was highly significant for PPY and protein yield. A haplotype analysis using results of previous studies of the same design revealed a co‐segregation of various persistency QTL and QTL affecting health traits like dystocia and stillbirth and functional traits like non‐return rate 90 and somatic cell score.  相似文献   
3.
Eight harbour seals (Phoca vitulina), two of them seronegative, six seropositive against PDV and a seronegative grey seal (Halichoerus grypus) were exposed to a low doses of a cell culture-propagated phocine distemper virus isolate (PDV 2558/Han 88). An intranasal route of inoculation was chosen. Clinical signs, resembling those of 1988's seal disease and seroconversion were observed in both seronegative harbour seals. One of them succumbed to the infection. The virus was not transmitted to another susceptible harbour seal which served as in-contact animal. Virus could be recovered from leucocytes of the diseased seals. Viremia was also present in a seropositive harbour seal that developed mild clinical signs; other seropositive seals were protected from clinical disease. The grey seal showed seroconversion upon inoculation, but did not develop any signs of disease. The humoral immune response of the seals plainly discriminated between homologous (PDV) and heterologous (canine distemper virus, CDV) virus as shown by virus neutralization tests and an antibody-binding assay (PLA).  相似文献   
4.
Smout  TC 《Forestry》2006,79(3):341-349
Human use of the pinewoods in 1600–1900 is briefly reviewed,and related to evidence for differing woodland structure inthese centuries. A certain number of pinewoods were lost between1600 and 1800 and it is suggested that this may be related toclimate change.  相似文献   
5.
The relationship between the serological classification system for serogroup B and for serogroup H of Bacteroides nodosus and cross-protection between subgroups within these serogroups was examined. Protection against ovine footrot following vaccination was achieved against other subgroup strains provided sufficient cross-reactive antibody was induced by shared pilus antigens. Within serogroup B, better cross-protection against one subgroup was obtained with a pili vaccine than a whole cell vaccine which correlated with higher pilus antibody titres induced by the former. For serogroup H, a lack of cross-protection and serological reactivity between subgroups was demonstrated, which indicates that the prototype strain of subgroup H2 should be designated a new serogroup.  相似文献   
6.
The occurrence of fertile oestrus early in the breeding season is of paramount importance to the Thoroughbred industry to facilitate early conception. This paper compares 2 techniques for inducing fertile oestrus in anoestrous mares using either an extended photoperiod alone or together with gonadotrophin-releasing hormone (GnRH) infusions. Eleven mares were placed under conditions of 16 h light and 8 h darkness and 5 of these were implanted with osmotic minipumps delivering approximately 100 ng GnRH/kg/h for 28 days (treated mares). The treated mares ovulated 27.7 days earlier than and conceived 32 days earlier than the 6 mares not given GnRH. GnRH-induced ovulations were followed by a competent luteal phase. The combination of GnRH pumps implanted 2 weeks before commencement of service together with extended photoperiod from July 1 has promise in assisting the stud breeder to improve reproductive efficiency on commercial stud farms.  相似文献   
7.
Our research assesses the feasibility of using artificial selection on pre-mating floral traits to modify the mating system of faba bean (Vicia faba). This analysis considered two synthetic populations, which were derived from different genetic pools and had undergone five years of multiplication. For these populations, we identified floral and inflorescence traits that influence outcrossing per plant and examined the relative importance of these traits in governing yield. Codominant isozyme loci and the mixed-mating model were used to estimate the multilocus female outcrossing rate. A maternal half-sib design was used to evaluate the additive genetic component of floral and inflorescence traits, yield and yield components. Multiple regression was used to assess the effects of floral and inflorescence traits on outcrossing and yield and components of yield. The two populations exhibited mixing mating. Self-fertilization appears to result from the action of pollinating bees, so that its incidence could be modified by selection on floral and inflorescence traits that affect pollination. Floral and inflorescence traits affected individual differences in outcrossing unequally, with most variation being associated with the numbers of displayed flowers and inflorescences. Variation among plants in reward traits and in shape, although statistically significant, had limited and inconsistent influences on individual differences in outcrossing. Yield and its components varied strongly with aspects of floral display and, to a lesser extent, floral design, except for seed weight. Overall, our results imply that both outcrossing and yield could be enhanced by selection for plants that produce more inflorescences, each with relatively few flowers.  相似文献   
8.
A Chemoautotrophically Based Cave Ecosystem   总被引:1,自引:0,他引:1  
Microbial mats discovered in a ground-water ecosystem in southern Romania contain chemoautotrophic bacteria that fix inorganic carbon, using hydrogen sulfide as an energy source. Analysis of stable carbon and nitrogen isotopes showed that this chemoautotrophic production is the food base for 48 species of cave-adapted terrestrial and aquatic invertebrates, 33 of which are endemic to this ecosystem. This is the only cave ecosystem known to be supported by in situ autotrophic production, and it contains the only terrestrial community known to be chemoautotrophically based.  相似文献   
9.
Protein O-mannosylation is an essential and evolutionarily conserved post-translational modification among eukaryotes. This form of protein modification is also described in Mycobacterium tuberculosis; however, the mechanism of mannoprotein assembly remains unclear. Evaluation of differentially translocated chimeric proteins and mass spectrometry to monitor glycosylation demonstrated that specific translocation processes were required for protein O-mannosylation in M. tuberculosis. Additionally, Rv1002c, a M. tuberculosis membrane protein homolog of eukaryotic protein mannosyltransferases, was shown to catalyze the initial step of protein mannosylation. Thus, the process of protein mannosylation is conserved between M. tuberculosis and eukaryotic organisms.  相似文献   
10.
Novel Colloidal Interactions in Anisotropic Fluids   总被引:2,自引:0,他引:2  
Small water droplets dispersed in a nematic liquid crystal exhibit a novel class of colloidal interactions, arising from the orientational elastic energy of the anisotropic host fluid. These interactions include a short-range repulsion and a long-range dipolar attraction, and they lead to the formation of anisotropic chainlike structures by the colloidal particles. The repulsive interaction can lead to novel mechanisms for colloid stabilization.  相似文献   
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