The African wild cat is one of the smallest wild cats and its future is threatened by hybridization with domestic cats. Nuclear transfer, a valuable tool for retaining genetic variability, offers the possibility of species continuation rather than extinction. The aim of this study was to investigate the ability of somatic cell nuclei of the African wild cat (AWC) to dedifferentiate within domestic cat (DSH) cytoplasts and to support early development after nuclear transplantation. In experiment 1, distributions of AWC and DSH fibroblasts in each cell-cycle phase were assessed by flow cytometry using cells cultured to confluency and disaggregated with pronase, trypsin, or mechanical separation. Trypsin (89.0%) and pronase (93.0%) yielded higher proportions of AWC nuclei in the G0/G1 phase than mechanical separation (82.0%). In contrast, mechanical separation yielded higher percentages of DSH nuclei in the G0/G1 phase (86.6%) than pronase (79.7%) or trypsin (74.2%) treatments. In both species, pronase induced less DNA damage than trypsin. In experiment 2, the effects of serum starvation, culture to confluency, and exposure to roscovitine on the distribution of AWC and DSH fibroblasts in various phases of the cell cycle were determined. Flow cytometry analyses revealed that the dynamics of the cell cycle varied as culture conditions were modified. Specifically, a higher percentage of AWC and DSH nuclei were in the G0/G1 phase after cells were serum starved (83% vs. 96%) than were present in cycling cells (50% vs. 64%), after contact inhibition (61% vs. 88%), or after roscovitine (56% vs. 84%) treatment, respectively. In experiment 3, we evaluated the effects of cell synchronization and oocyte maturation (in vivo vs. in vitro) on the reconstruction and development of AWC-DSH- and DSH-DSH-cloned embryos. The method of cell synchronization did not affect the fusion and cleavage rate because only a slightly higher percentage of fused couplets cleaved when donor nuclei were synchronized by serum starvation (83.0%) than after roscovitine (80.0%) or contact-inhibition (80.0%). The fusion efficiency of in vivo and in vitro matured oocytes used as recipient cytoplasts of AWC donor nuclei (86.6% vs. 85.2%) was similar to the rates obtained with DSH donor nuclei, 83.7% vs. 73.0%, respectively. The only significant effect of source of donor nucleus (AWC vs. DSH) was on the rate of blastocyst formation in vitro. A higher percentage of the embryos derived from AWC nuclei developed to the blastocyst stage than did embryos produced from DSH nuclei, 24.2% vs. 3.3%, respectively (P < 0.05). In experiment 4, the effect of calcium in the fusion medium on induction of oocyte activation and development of AWC-DSH-cloned embryos was determined. The presence of calcium in the fusion medium induced a high incidence of cleavage of DSH oocytes (54.3%), while oocyte cleavage frequency was much lower in the absence of calcium (16.6%). The presence or absence of calcium in the fusion medium did not affect the fusion, cleavage, and blastocyst dev...
The results of seven serologic tests for diagnosis of human brucellosis were evaluated. The titrated Rose Bengal test, microagglutination test, microtiter-adapted Coombs test, and immunocapture-agglutination test (Brucellacapt) were positive for all sera from patients with acute brucellosis. The immunoglobulin G (IgG), IgM, and IgA commercial enzyme immunoassays (ELISAs) failed to show specific antibodies in 3 patients, 10 patients, and 1 patient, respectively. The sensitivity of ELISA is not higher than that of conventional tests.Brucellosis is an endemic zoonotic disease in many parts of the world, notably in Mediterranean countries and the Middle East. The diagnosis of brucellosis is made by the isolation of Brucella species (i.e., in blood cultures), but this method is successful in only 40 to 70% of cases (18). Therefore, laboratory diagnosis of brucellosis very often relies on detecting specific serum antibodies (5, 19). Several serological tests have been used for the diagnosis of human brucellosis. The serum agglutination test (SAT) for brucellosis, developed by Wright et al. in 1897 (17), is still the reference to which other tests are compared. Other notable tests that have been developed since then are the Rose Bengal test, complement fixation test, indirect Coombs test, enzyme immunoassay (ELISA) (6, 15), and, more recently, an immunocapture-agglutination test (Brucellacapt) (10). However, the interpretation of these tests is often difficult in areas of endemicity in which a large part of the population has contact with animals or products of animal origin and could develop antibodies against Brucella. In this study, the results obtained with seven different tests for detection of Brucella-specific antibodies in an area of endemicity were analyzed. A 12-month clinical and serologic follow-up was performed after the treatment was started. As a reference, the antibody levels in the healthy population of that area were also tested.One hundred twenty serum samples from 25 patients with acute brucellosis and 90 from healthy individuals (blood donors) were included in this study. The diagnosis of brucellosis was based on clinical findings and on either positive blood cultures for Brucella or the presence of serum antibodies (SAT titer Ն 160). At least three blood cultures were drawn from each patient at diagnosis. Follow-up cultures were drawn at the end of the treatment and 3, 6, and 12 months later. For four patients the 12-month cultures were not performed. Brucella was identified according to MunichЈs taxonomy criteria (8). Serum samples were collected on admission and 1, 3, 6, and 12 months later. For four patients the 12-month control sample was not assayed. For the group of blood donors only one serum sample was analyzed. The titrated Rose Bengal test, microagglutination test (MAT), microtiter-adapted Coombs test, Brucellacapt, and ELISAs for immunoglobulin M (IgM), IgG, and IgA antibodies were performed on each serum sample. The microtiter-adapted Coombs test was not performed for the group of hea...
In the present study, we used the African Wildcat (Felis silvestris lybica) as a somatic cell donor to evaluate the in vivo developmental competence, after transfer into domestic cat recipients, of cloned embryos produced by the fusion of African Wildcat (AWC) fibroblast cell nuclei with domestic cat cytoplasts. Cloned embryos were produced by fusion of a single AWC somatic cell to in vivo or in vitro enucleated domestic cat cytoplasts. When the two sources of oocytes were compared, fusion rate was higher using in vivo-matured oocytes as recipient cytoplasts, but cleavage rate was higher after reconstruction of in vitro-matured oocytes. To determine the number of reconstructed embryos required per domestic cat recipient to consistently establish pregnancies, AWC cloned embryos were transferred within two groups: recipients (n = 24) receiving < or =25 embryos and recipients (n = 26) receiving > or =30 embryos. Twelve recipients (46.2%) receiving > or =30 embryos were diagnosed to be pregnant, while no pregnancies were established in recipients receiving < or =25 NT embryos. Also, to determine the influence of length of in vitro culture on pregnancy rate, we compared oviductal transfer on day 1 and uterine transfer on day 5, 6, or 7. Pregnancy rates were similar after transfer of embryos on day 1 (6/12; 50.0%), day 5 (4/9; 44.4%), or day 6 (2/5; 40.0%) to synchronous recipients, but the number of fetuses developing after transfer of embryos on day 1 (n = 17), versus day 5 (n = 4) or day 6 (n = 3) was significantly different. Of the 12 pregnant recipients, nine (75%) developed to term and fetal resorption or abortion occurred in the other three (25%) from day 30 to 48 of gestation. Of a total of 17 cloned kittens born, seven were stillborn, eight died within hours of delivery or up to 6 weeks of age, and two are alive and healthy. Perinatal mortality was due to lung immaturity at premature delivery, placental separation and bacterial septicemia. Subsequent DNA analysis of 12 cat-specific microsatellite loci confirmed that all 17 kittens were clones of the AWC donor male. These AWC kittens represent the first wild carnivores to be produced by nuclear transfer.
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