Sequence Analysis of Attachment Gene of Lumpy Skin Disease and Sheep Poxviruses

In Egypt,protection of cattle against lumpy skin disease (LSD) was carried out using a sheep poxvirus (Kenyan strain) vaccination strategy.In the present study 15 skin nodules from LSD suspected cows and 5 scab samples from sheep pox (SP) suspected sheep were collected.Hyperimmune rabbit sera to Lumpy skin disease virus (LSDV)/Ismailyia88 strain and sheep pox virus (SPV)/ Kenyan vaccinal strain were prepared.The causative agent in the collected samples was identified using immunoflourescence (IF) and immuno...     

Sequence analysis of attachment gene of lumpy skin disease and sheep poxviruses

In Egypt, protection of cattle against lumpy skin disease (LSD) was carried out using a sheep poxvirus (Kenyan strain) vaccination strategy. In the present study 15 skin nodules from LSD suspected cows and 5 scab samples from sheep pox (SP) suspected sheep were collected. Hyperimmune rabbit sera to Lumpy skin disease virus (LSDV)/Ismailyia88 strain and sheep pox virus (SPV)/ Kenyan vaccinal strain were prepared. The causative agent in the collected samples was identified using immunoflourescence (IF) and immunoperoxidase techniques. Of the 15 skin nodules suspected of LSD, 10 showed a positive reaction and 3 out of 5 skin scabs suspected of sheeppox were found to be positive. An antigenic correlation between field skin isolate of LSDV, tissue culture adapted LSDV/Ismailyia88 strain, field skin isolate of SPV and SPV/Kenyan vaccinal strain was studied using prepared hyperimmune sera. Also, nucleotide sequence of the PCR amplified attachment gene fragments of field skin isolate of LSDV, tissue culture adapted LSDV/Ismailyia88 strain, field skin isolate of SPV and SPV /Kenyan vaccinal strain were compared. The results revealed that the four used viruses were antigenically identical. Sequence analysis indicated that field skin LSDV isolate is more related to tissue culture adapted LSDV/Ismailyia88 strain than to vaccinal SPV/ Kenyan strain and the skin isolate of SPV is more closely related to field skin isolate of LSDV than to SPV/Kenyan vaccinal strain. Thus, further study should be applied on the advantage of a LSD vaccine prepared from LSDV in protection of cattle against LSD compared to the commonly used sheep pox vaccine.     

Volatiles from Merino fleece evoke antennal and behavioural responses in the Australian sheep blow fly Lucilia cuprina

To identify flystrike‐related volatile compounds in wool from Merino sheep, the attractiveness of wool to Lucilia cuprina Wiedmann (Diptera: Calliphoridae) was examined. First, a selection of wool samples guided by previous knowledge of sheep lines, predicted to be more susceptible or more resistant to flystrike, was tested. The attractiveness of the 10 samples selected was not associated with field susceptibility: two samples from the more resistant line were identified as most attractive and two samples from the more susceptible line were identified as least attractive, based on the behavioural assays with gravid flies. Comparison of the headspace volatiles of these samples, using solid phase microextraction and gas chromatography‐mass spectrometry‐electroantennographic detection, revealed octanal and nonanal to be present in the attractive wool samples that elicited responses from the fly antenna. Furthermore, the two compounds were not present in wool that was least attractive to L. cuprina. In laboratory bioassays, octanal and nonanal evoked antennal and behavioural responses in gravid L. cuprina, thus confirming their potential role as semiochemicals responsible for attracting L. cuprina to Merino sheep.     

Lumpy jaw in wild sheep and its evolutionary implications

The distribution and prevalence of mandibular osteomyelitis, lumpy jaw, and other dental anomalies in wild sheep were investigated and their biological and evolutionary implications were assessed. Our survey was based on 3,363 mandibles of wild sheep and 1,028 from domesticated varieties. Lumpy jaw is widespread in wild sheep of North America, but it is rare or absent in wild sheep from Eurasia. Among the subspecies of Ovis spp. in North American, the thinhorn sheep (Ovis dalli) were the most seriously impacted, with a prevalence in Dall's sheep (O. dalli dalli) of 23.3% and 29.3% in Stone's sheep (O. dalli stonei). Among the bighorns (O. canadensis), the Rocky Mountain subspecies (O. canadensis canadensis) had a higher rate (12.1%) than other subspecies. Lumpy jaw was not documented in the desert sheep of Baja California (O. canadensis cremnobates, O. canadensis weemsii). Based on data from affected thinhorn sheep, it appears there is an inverse relationship between age of a subspecies in a long term evolutionary context and susceptibility to lumpy jaw. In Eurasian wild sheep lumpy jaw is rare or absent with prevalences ranging from 0 to 7.1% among suspecies, and in domesticated breeds the prevalence averaged 5.0%. The impact of lumpy jaw on different age classes or longevity is equivocal, although females are more susceptible than males. Lumpy jaw appears to effect horn development in males.     

Sheep wool (glycine + tyrosine)-rich keratin genes. A family of low sequence homology

We report the isolation and complete nucleotide sequence of genes encoding the two major high-(glycine + tyrosine) (HGT) keratins of sheep wool in separate genomic clones. The genes have negligible sequence homology except for an 18-bp conserved element immediately preceding the initiation codon. The same element has been found in the corresponding position of a number of co-expressed high-sulphur (HS) keratin genes and may therefore represent a common element between these wool intermediate-filament-associated proteins. As seen for the HS keratin genes, the HGT keratin genes also lack introns. Southern blot data show that both HGT genes are unique in the sheep genome, indicating that the observed heterogeneity of the HGT protein class may not be as complex as previously suggested.     

A comparison of methods for inoculating bean plants with Elsinoë phaseoli and some factors affecting infection

Bean (Phaseolus vulgaris) leaves were inoculated with a conidial suspension of Elsinoe phaseoli by spraying, by applying a 10 μl drop, by a cotton wool technique or by using a camel hair brush. Spray application resulted in a uniform distribution of lesions over the leaf surface and gave consistent levels of infection between repetitions. Drop application allowed good control of the amount of inoculum applied. Although brush or cotton wool techniques gave high levels of infection it was not possible to control the amount of inoculum. Only immature tissues were susceptible to infection. Five cultivars were inoculated with two isolates and disease was scored on the basis of numbers of lesions and lesion type (scab severity). The small white cvs PAN 181 and Teebus were the most resistant; lesions were small and generally fewer than on the large-seeded red speckled sugar bean cvs Umlazi and Umvoti. The value of the different inoculation techniques in studies on bean scab is discussed.     

Single nucleotide polymorphism for animal fibre identification

Animal fibres are highly valuable industrial products often adulterated during marketing. Currently, there is no precise method available to identify and differentiate the fibres. In this study, a PCR-RFLP technique was exploited to differentiate cashmere and wool fibres derived from goat and sheep, respectively. The presence of DNA in animal hair shafts has enabled the isolation of DNA from scoured cashmere and wool fibres. The mitochondrial cytochrome b sequences of both species were amplified by PCR using primers designed from conserved regions. The polymorphism observed between the two species was detected by restricting the amplified product by endonucleases viz., BamH1 and Ssp1. The RFLP profile clearly distinguishes the cashmere and wool fibres and this technique can also be exploited to test adulteration in animal fibres qualitatively.     

Improvement of wool production through genetic engineering.

Wool is a natural fibre popular in the manufacture of outer clothing and is a vital source of income for several countries. Fundamental knowledge of how wool grows has been gained from research on the biology of sheep, and the prospects ahead are to take advantage of the development and application of recombinant DNA technology to improve the efficiency of production of wool and its quality. This review surveys the possibilities for producing transgenic sheep, modifying rumen bacteria and forage crops, thus increasing the nutritional benefit sheep gain from pasture.     

Key determinants affecting sheep wool biodegradation directed by a keratinase-producing <Emphasis Type="Italic">Bacillus subtilis</Emphasis> recombinant strain

OVAT (one variable at a time) approach was applied in this study to screen the most important physicochemical key determinants involved in the process of sheep wool biodegradation. The process was directed by a keratinase-producing Bacillus subtilis DB 100 (p5.2) recombinant strain. Data indicate that, sheep wool could be degraded efficiently in cultures incubated at 30°C, with initial pH of 7 with agitation at 150 rpm. Two times autoclaved alkali treated and undefatted chopped sheep wool is more accessible to biodegradation. B. subtilis recombinant cells could utilize sheep wool as a sole source of carbon and nitrogen. Sheep wool-based modified basal medium II, lacking NH₄Cl and yeast extract, could greatly support the growth of these bacterial cells. Sheep wool biodegradation was conducted efficiently in the absence of kanamycin consequently; high stability of the recombinant plasmid (p5.2) represents a great challenge upon scaling up this process. Three key determinants (sheep wool concentration, incubation time and inoculum size) imposing considerable constraints on the process are highlighted. Sheep wool-based tap water medium and sheep wool-based distilled water medium were formulated in this study. High levels of released end products, produced from sheep wool biodegradation are achieved upon using these two sheep wool-based water media. Data indicate that, sheep wool hydrolysate is rich in some amino acids, such as tyrosine, phenylalanine, lysine, proline, isoleucine, leucine, valine, aspartic acid and glutamic acid. Moreover, the resulting sheep wool hydrolysate contains soluble proteins of high and intermediate molecular weights. The present study demonstrates a feasible, cheap, reproducible, efficient and rapid biotechnological approach towards utilization of raw sheep wool waste through a recombinant bacterium.     

The dietary-regulated biosynthesis of high-sulphur wool proteins

1. When the diet of sheep is supplemented by the abomasal infusion of sulphur-containing amino acids or casein, a special group of proteins, with a very high content of sulphur (about 8.3%), is incorporated into the high-sulphur proteins of wool. These special proteins cannot be detected in control wool from the same sheep. 2. This is a naturally occurring process, as these special proteins are found in wool from sheep on a high level of nutrition under ordinary conditions of feeding, and in wool of an inherently high sulphur content. 3. This represents a control mechanism in protein synthesis that has not previously been observed, and may be further evidence that the high-sulphur proteins of wool are produced by an unusual synthetic route.     

Wild birds and silage as reservoirs of Listeria in the agricultural environment

A method for the isolation of listeria which enabled a more rapid detection of the organism was used to examine samples of silage and bird faeces. Faecal samples indicated that seagulls feeding at sewage works had a higher rate of carriage than those elsewhere. Faecal samples from rooks generally suggested a low incidence of listeria except on one occasion when eight of twenty samples contained Listeria monocytogenes: this coincided with the nesting season and the peak period for listeriosis in sheep. The incidence of L. monocytogenes in clamp silages ranged from 2.5-5.9%, but in samples of big bale silages the incidence was 22.2% and, when mouldy samples were selected, 44%.     

Effects of phenylalanine and analogues of methionine and phenylalanine on the composition of wool and mouse hair

Administration of the methionine analogue methoxinine (O-methyl-DL-homoserine) to sheep substantially changed the composition of wool; in addition wool fibres were weakened and the staple crimp frequency was reduced for a prolonged period. The proportions of high-tyrosine proteins were reduced by 40-45% whereas the high-sulfur proteins were usually slightly increased. The content of high-tyrosine proteins in wool was still depressed in most sheep 70 days after dosing with methoxinine. These experiments supported a previous finding that the cystine content of wool and its crimp frequency are not causally related. Ethionine, another methionine analogue, did not consistently change the composition of wool. In some sheep there was no change in the proportions of high-tyrosine proteins following administration of ethionine, even though weak wool was produced. This result, together with the lack of association between the content of high-tyrosine proteins and the strength of wool fibres in a sheep given methoxinine plus methionine, indicates that a reduction of the high-tyrosine proteins is not a prerequisite for the production of weak wool. Neither a threefold increase in the phenylalanine intake by mice nor the administration of three analogues of phenylalanine (4-fluoro-DL-phenylalanine, 4-chloro-DL-phenylalanine and beta-(2-thienyl)-DL-alanine) to sheep altered the composition of hair or wool. Fluorophenylalanine was incorporated into all the constituent proteins of wool to the extent of c. 2% of phenylalanine residues. The other analogues studied could not be detected in wool.     

Wild birds and silage as reservoirs of Listeria in the agricultural environment

A method for the isolation of listeria which enabled a more rapid detection of the organism was used to examine samples of silage and bird faeces. Faecal samples indicated that seagulls feeding at sewage works had a higher rate of carriage than those elsewhere. Faecal samples from rooks generally suggested a low incidence of listeria except on one occasion when eight of twenty samples contained Listeria monocytogenes: this coincided with the nesting season and the peak period for listeriosis in sheep. The incidence of L. monocytogenes in clamp silages ranged from 2.5–5.9%, but in samples of big bale silages the incidence was 22.2% and, when mouldy samples were selected, 44%.     

Maintaining <Emphasis Type="Italic">Psoroptes ovis</Emphasis> (Acari: Psoroptidae) off-host in the laboratory

Feeding and maintaining sheep scab mites off-host is an important step towards achieving a safer, environmentally-friendly means of controlling sheep scab disease. The test arena developed by Thind and Muggleton (Exp Appl Acarol 22:543–552, 1998) has been adapted for feeding and maintaining Psoroptes ovis off-host. The test arenas are simple to construct and use, and escape-proof to all stages of mites. The performance of the test arenas was assessed by determining the survival of the scab mites at 33 and 36°C and >95% r.h. on different diets. With this test arena the best reported mean survival of 10.3 days was achieved with both females and nymphs at a temperature of 33°C on a diet of sheep serum; the mean maximum survival of females at these conditions was 18.8 days, which is at least a threefold improvement on previous reports. With further development it may be possible to adapt the test arena for assessing both slow and fast acting agents for controlling sheep scab. The British Crown’s right to retain a non-exclusive, royalty-free licence in and to any copyright is acknowledged.     

THE OLFACTORY BEHAVIOUR OF LUCILIA SPECIES (DIPTERA) UNDER NATURAL CONDITIONS

Using an apparatus of the 'two-choice' type under field conditions, it has been demonstrated that a wool-factor forms an important part of the mechanism whereby female Lucilia sericata may be attracted to sheep. The 'wool-factor' could not wholly be replaced by ammonium- or sulphydryl-type attractants.
L. sericata was strongly attracted by the combination of ammonium carbonate/indole with sheep wool but less strongly attracted when ethyl mercaptan/hydrogen sulphide was used with sheep wool. L. caesar and L. illustris , on the other hand, were not markedly responsive to the ammonium-type attractants but were strongly attracted by the sulphydryl mixture used either alone or in combination with sheep wool.
Temperature is an important element in the oviposition stimulus. The amount of oviposition by L. sericata was increased when substances known to induce oviposition were exposed at 30–40† C.
Sheep wool kept moist and incubated at approx. 38† C. under field conditions for 3 weeks did not attract L. sericata and oviposition did not occur on such wool. This suggests that bacteria normally present on the wool fibre as distinct from the skin, do not play an important part in rendering sheep susceptible to blowfly attack.     

绵羊皮肤中GHR、IGF-1和IGF-1R基因表达的发育性变化及品种特点

采用相对定量反转录多聚酶链式反应 (RT-PCR)方法, 以18S rRNA作内标, 研究了罗米丽(Romilly Hillys)×中国美利奴(新疆军垦型)杂交一代优质细毛羊和哈萨克粗毛羊皮肤中生长激素受体(GHR)、胰岛素样生长因子1(IGF-1)和胰岛素样生长因子1受体(IGF-1R) mRNA发育性变化并进行了品种间比较。分别于30、60、90、135、180和255日龄称重、采毛样, 并于30、90、135和255日龄采皮样。结果表明: 粗毛羊和细毛羊体重、羊毛生长的发育模式没有明显的差异, 30~135日龄体重迅速增加, 135~255日龄增重十分缓慢; 30~135日龄羊毛日增长逐渐增加, 135~180日龄羊毛生长十分缓慢, 而180~255日龄又上升到较高水平。粗毛羊皮肤中GHR mRNA在30~90日龄显著增加 (P<0.05), 90日龄达到高峰, 此后显著下降(P<0.05); 细毛羊在135日龄时GHR mRNA极显著地升高(P<0.01), 此后又极显著地下降。粗毛羊皮肤中IGF-1、IGF-1R mRNA 30~90日龄上升, 90日龄之后极显著下降(P<0.01); 细毛羊皮肤中IGF-1、IGF-1R mRNA出生时较高, 然后逐渐下降。品种之间比较, 细毛羊GHR mRNA出现高峰晚于粗毛羊, 135日龄高峰时显著地高于粗毛羊; 粗毛羊IGF-1、IGF-1R mRNA在90日龄出现高峰, 并极显著或显著地高于细毛羊; 粗毛羊90日龄前GHR、IGF-1和IGF-1R mRNA高于细毛羊, 之后低于细毛羊。结果提示: 绵羊皮肤中GHR、IGF-1和IGF-1R基因表达有特定的发育模式, 并存在品种差异。     

Wool proteins of New Zealand Romney sheep

Proteins extracted from the wool of 65 Romney ewes were analysed qualitatively by one- and two-dimensional polyacrylamide gel electrophoresis. Romney wool proteins could be classified into the low-sulfur, high-sulfur, and high-tyrosine protein groups described for wool from other breeds. The wool protein pattern of an individual sheep remained constant despite changes in season, age or nutritional status of the sheep, and did not vary between different body positions. There were between-sheep differences in protein pattern, most variation occurring in the high-sulfur protein group. These differences were presumed to reflect genetic differences between the sheep.     

Influence of hydrothermal factors on wool development of Tan sheep in China

Hydrothermal factors in Ningxia, an arid and semi-arid area in Northwestern China, were examined to determine their influence on the geographical differentiation of the wool quality of Tan sheep lambskin. Prospective areas for extension of the Tan sheep industry were also investigated. Two sheep groups were sampled; one consisted of artificial insemination flocks (1241 lambs sampled from 25 flocks) and the other of natural mating flocks (1009 lambs from 38 flocks). Six phenotypical traits were measured for each lamb and six hydrothermal factors were collected from the meteorological stations located in the sampling areas. A significant correlation was found between wool characteristics of the lambskin and hydrothermal conditions. Data further indicated that among all the hydrothermal factors measured, those causing the geographical differentiation of soil and vegetation were the major factors responsible for the corresponding differentiation of the lambskin and wool quality of Tan sheep. Thermal factors were mostly positively correlated with wool quality, while the influence of moisture was negative. Three eco-geographical regions were defined based on a combination of the hydrothermal conditions and corresponding wool characters: (i) typical region or super-suitable region, (ii) sub-typical region or suitable region and (iii) transitional region. The delimitation could be used as a basis for the extension of the Tan sheep industry. It is also suggested that the wool quality of lambskin of Tan sheep in these three regions could be improved by means of controlled breeding and selection.     

Genetic control of alopecia in sheep

A hypothesis is suggested which turns down the opinion that alopecia or pathological wool shedding in sheep is due to some pathological processes or disease. We suppose that this trait is controlled by a gene of natural wool shedding inherited from sheep far ancestors, and we propose to designate the recessive alopecia gene as Alp3 and its dominant allele, a wool alopecia resistance gene, as AlpA. Alopecia will only be revealed in homozygotic Alpa/Alpa state, due to recessivity of alopecia gene, but heterozygotic AlpA/Alpa and homozygotic AlpA/AlpA sheep will have a normal wool coat. A new polymorphic trait is supposed to exist which is conditioned by simultaneous presence of two genetic alleles in a sheep population with descrete phenotypic manifestation.     

Effect of phenothiazine derivative on adrenal cortex response of sheep to repeated emotional stress]

The study was aimed at the evaluation of propiopromazine (Combelen, Bayer), a derivative of phenothiazine, as an agent lowering in sheep the response to stress. The stress of emotional origin was induced in sheep by the isolation from herd lasting 1 hour. The isolation experiments were repeated 6 times on the same group of sheep, first three isolations (1-3) in daily intervals and next three (4-6) in weekly intervals. Propiopromazine was administered before each isolation experiment. The reaction of sheep to the isolation stress was weaker after propiopromazine administration. This was suggested by smaller increase in blood serum cortisol and glucose levels when compared to sheep subjected to isolation but not receiving the drug. Such effect was especially conspicuous during the course of the first isolation experiment; during the next experiments the difference concerning the reaction to stress between the sheep isolated from the herd receiving and not receiving the drug was gradually diminishing. It was shown in addition that propiopromazine administration to the sheep not subjected to stress caused an increase in cortisol level by 125 per cent and that in glucose level by 35 per cent. These results suggest that propiopromazine administration protects the organism against the effects of emotional stress only partially. Moreover, the effect of its administration gradually weakens with repeating of the stress inducing experiment, and propiopromazine itself may act as a stress inducing factor. It seems therefore that the use of propiopromazine and similar compounds as anti-stress agents may be questionable.