Rapid evolution of horse satellite DNA Wijers, E.R; Zijlstra, C; Lenstra, J.A
Genomics (San Diego, Calif.),
10/1993, Letnik:
18, Številka:
1
Journal Article
Recenzirano
The major satellite of the horse genome consists of about 1 million copies of a 221-bp tandem repeat unit. By fluorescence in situ hybridization it has been localized in the centromeres of 58 of the ...64 horse chromosomes. The donkey genome contains a similar but not identical satellite. Strikingly, the equine repeat did not hybridize to DNA of the Grevy zebra, despite the divergence of the horse and zebra only 3 to 5 million years ago and the ability of these species to crossbreed. The evolution of satellite DNA in the Equidae is more rapid than that in other mammalian families, which may be explained by their rapid karyotypic evolution.
The pathophysiology and lesions associated with vitamin E deficiency are similar between domestic and exotic species, and circulating plasma concentrations are also similar between comparable groups. ...However, many ecological variables must be considered for the most relevant comparisons. Tissue values of vitamin E, apart from plasma, are unknown for most exotics. Dietary vitamin E requirements of exotic species and domestics appear to differ; based on natural foodstuff analyses and clinical observations, between 50 and 200 mg vitamin E/kg DM are necessary to prevent vitamin E deficiency, 5- to 10-fold higher than current livestock recommendations.
A manual technique was used to collect representative ejaculates from an unrestrained Grevy's zebra stallion beginning at 13 mo of age to determine the onset of sperm production, to calculate the ...number of spermatozoa produced per ejaculate, and to determine any seasonality associated with sperm production. Spermatozoa first appeared in the ejaculate at 31 mo of age. By 48 mo of age the zebra was producing up to 40 billion spermatozoa per ejaculate. Progressive sperm motility ranged from 75 to 95%. Gel-free semen volume averaged 75 to 120 ml/ejaculate. Gel volume ranged from 0 to 1100 ml/ejaculate. Semen was frozen in 2 different extenders in 0.5-ml PVC straws. The post-thaw motility of cryopreserved spermatozoa ranged from 30 to 70%. A domestic horse mare became pregnant on the first cycle after insemination with frozen-thawed spermatozoa from this zebra. Sperm production data obtained from semen collections made on a Grant's Zebra stallion from 3 to 8 yr of age is presented for comparison of the 2 species
Ninety-two equine herpesvirus type 1 isolates were recovered from aborted, stillborn, or neonatal foals from Ontario, Canada, from 1986 to 1992. From this total, 32 strains were randomly chosen for ...further study. Four or 5 isolates from each winter were selected, each from a different premises, and characterized by restriction enzyme analysis using BamHI, KpnI, BglII, HindIII, and EcoRI. Additional isolates from 2 premises and from a zebra foal were also assessed. For the strains isolated in 1986 and 1989-1992, the DNA pattern of 18 strains was similar to that of type 1P (Kentucky D) for BamHI and KpnI. None of the 32 strains studied could be differentiated by HindIII or EcoRI. Using BglII, an inconsistent fragment pattern and distribution were observed. Of the 8 strains isolated in 1987 and 1988, 7 were assigned into the 1B prototype group. The geographic distribution of 17 type 1P and 12 1B isolates was random across southern Ontario. These findings suggest that both electropherotypes can be recovered from horses in Ontario. The patterns of the additional equine isolates from the same premises were identical. The zebra isolate was different from the prototype equine herpesvirus type 1 and type 4 patterns and from all other equine isolates.
Ivermectin toxicosis in a zebra Hautekeete, L.A; Khan, S.A.A; Hales, W.S
Veterinary and human toxicology,
02/1998, Letnik:
40, Številka:
1
Journal Article
Recenzirano
A 3-mo-old zebra was accidentally given 2.08 mg ivermectin/kg bw orally. Ataxia, blindness and depression developed within a few hours and resolved with symptomatic and supportive treatment by the ...fifth day post-exposure. These effects were similar to those reported in horses, including the temporary blindness.
Enterolithiasis in two zebras McDuffee, L.A; Dart, A.J; Schiffman, P ...
Journal of the American Veterinary Medical Association,
1994-Feb-01, Letnik:
204, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Enterolithiasis, as a cause of colic, was diagnosed and treated during surgical intervention in 2 Grant's zebras (Equus burchelli bohmi). The zebras were part of a wild herd in a zoo in the western ...United States. The clinical signs of enterolithiasis in both zebras were similar to those reported for horses. Analysis of the enterolith from 1 zebra revealed a composition identical to enteroliths that have been analyzed from horses. Three other zebras from this herd had enteroliths at necropsy. Enterolithiasis should be considered as a differential diagnosis for zebras with low-grade obstructive colic.
The viraemic period of African horsesickness is significantly longer in experimentally infected zebra than in horses. The virus could be isolated 40 d post-infection from blood and 48 d ...post-infection from spleen. The introduction of zebra into African horsesickness-free countries should therefore be considered carefully, and preferably be restricted to serologically negative zebra.
A survey was carried out in horse, zebra, elephant, camel, sheep and goat and wild carnivore sera for virus-serum neutralising antibody to the nine type strains of African horse sickness virus. ...Antibody was found amongst the horse, zebra and elephant sera to all nine different strains. No antibody was detected in any sera from camels, sheep and goats. None was found in sera from hyaena and jackals in this series but had been detected earlier.
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