The relationship between MHC-DRB1 gene second exon polymorphism and hydatidosis resistance of Chinese Merino (Sinkiang Junken type), Kazakh and Duolang sheep

The present study aimed at detecting the association of ovine major histocompatibility complex class II (Ovar II) DRB1 gene second exon and susceptibility or resistance to hydatidosis in three sheep breeds of Sinkiang. The MHC-DRB1 second exon was amplified by polymerase chain reaction (PCR) from DNA samples of healthy sheep and sheep with hydatidosis. PCR products were characterized by the restriction fragment length polymorphism (RFLP) technique. Five restriction enzymes, Mval, Haelll, Sacl, Sacll, Hin1l, were used, yielding 14 alleles and 31 restriction patterns. Frequencies of patterns Mvalbc, Hin1lab, Sacllab, Haelllde, Haellldf, Haellldd (P < 0.01) in Kazakh sheep, Saclab (P < 0.05) in Duolang sheep, and Haelllab, Haelllce, Haelllde, Haelllee (P < 0.01) in Chinese Merino (Sinkiang Junken type) sheep, were significantly higher in healthy sheep compared with infected sheep. These results indicated a strong association between these patterns and hydatidosis resistance. In contrast, the frequencies of Mvalbb, Saclaa, Hinl lbb, Haelllef (P < 0.01) and Haelllab (P < 0.05) in Kazakh sheep, Saclbb, Haelllae, Hin1lab (P < 0.05), Haelllaa, Haelllbe, Haelllef (P < 0.01) in Duolang sheep, Sacllaa (P < 0.05) and Haelllbd, Hin1lbb, Haelllcf, Haelllef (P < 0.01) in Chinese Merino sheep (Sinkiang Junken type) were significantly lower in healthy sheep compared with infected sheep. This indicated a strong association between these patterns and hydatidosis susceptibility. In addition, sheep with the pattern of Haelllef demonstrated a high hydatidosis susceptibility (P < 0.01) in all three breeds, while sheep with the pattern Haelllde demonstrated significant hydatidosis resistance (P < 0.01) in Kazakh and Chinese Merino sheep (Sinkiang Junken type). These results suggest that the Ovar-DRB1 gene plays a role in resistance to hydatidosis infection in the three sheep breeds.     

The Developmental Changes and Effect on IMF Content of H-FABP and PPARγ mRNA Expression in Sheep Muscle

Male Kazak sheep and Xinjiang fine wool sheep of different ages were selected to investigate the developmental changes and effect on intramuscular fat (IMF) content of heart fatty acid-binding protein (H-FABP) and peroxisome proliferator-activated receptor γ (PPARγ) mRNA expression in muscle. Longissimus dorsal muscle was sampled to measure IMF content; and total RNA was extracted to determine H-FABP and PPARγ mRNA expression levels by real-time PCR. The results showed that: (1) The IMF content increased continuously with growing and showed significant differences (P<0.05) between ages in male Kazak sheep, but no such differences (P>0.05) existed in Xinjiang fine wool sheep. Furthermore, the IMF content in Kazak sheep was very much higher (P<0.01) than that of the other breed from day 30 to 90; (2) H-FABP mRNA expression level was the highest on day 2 and showed significant differences (P<0.05) between ages in male Kazak sheep as well as in Xinjiang fine wool sheep. In the former breed, the expression reached the lowest point at day 30, and then rose continuously. But in the latter breed, it declined continuously from day 2 to 90, and then increased; (3) Significant differences (P<0.05) of PPARγ mRNA expression between ages occurred in both breeds. In male Kazak sheep, PPARγ mRNA expression declined from day 2 to 90, while in the other breed it increased continuously from day 2 to 60, but reached the lowest level at day 90, then increased; (4) In male Kazak sheep, the mRNA expression level of H-FABP was highly positively correlated (r=0.737, P<0.01) with IMF content from day 30 to 90, but that of PPARγ was highly negatively correlated (r=−0.835, P<0.01) with IMF content from day 2 to 90.     

Infection Status of Hydatid Cysts in Humans and Sheep in Uzbekistan

Uzbekistan is endemic of cystic echinococcosis (CE). In order to estimate endemicity of CE, we collected data from emergency surgery due to CE in 2002-2010 and also investigated the prevalence of hydatid cysts in the liver and lungs of sheep at an abattoir in Uzbekistan from July 2009 to June 2010. In 14 emergency hospitals, 8,014 patients received surgical removal or drainage of CE during 2002-2010, and 2,966 patients were found in 2010. A total of 22,959 sheep were grossly examined of their liver and lungs, and 479 (2.1%) and 340 (1.5%) of them were positive for the cyst in the liver and lungs, respectively. Echinococcus granulosus is actively transmitted both to humans and sheep, and CE is a zoonotic disease of public health priority in Uzbekistan.     

Evolutionary dynamics of endogenous Jaagsiekte sheep retroviruses proliferation in the domestic sheep,mouflon and Pyrenean chamois

The oncogenic exogenous Jaagsiekte sheep retrovirus (JSRV), responsible for ovine pulmonary adenocarcinoma, has several endogenous counterparts termed enJSRVs. Although many of these elements have been inactivated over time by the accumulation of deleterious mutations or internal recombination leading to solo long terminal repeat (LTR) formation, several members of enJSRVs have been identified as nearly intact and probably represent recent integration events. To determine the level of enJSRV polymorphism in the sheep population and related species, we have undertaken a study by characterizing enJSRVs copies and independent integration sites in six domestic sheep and two wild species of the sheep lineage. enJSRVs copies were detected by amplifying the env-LTR region by PCR, and for the detection of the insertion sites, we used two approaches: (1) an in silico approach based on the recently published Sheep Reference Genome Assembly (OARv3.0) and (2) an experimental approach based on PCR suppression and inverse PCR techniques. In total, 103 enJSRV sequences were generated across 10 individuals and enJSRV integrations were found on 11 of the 28 sheep chromosomes. These findings suggest that there are still uncharacterized enJSRVs, and that some of the integration sites are variable among the different species, breeds of the same species, subspecies and geographic locations.     

Biological Parameters of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) Fed on Rabbits,Sheep, and Cattle

In order to determine the effect of various hosts on feeding performance of Rhipicephalus (Boophilus) microplus, we used 3 mammalian species as hosts, cattle (Qinchuan), sheep (T an), and rabbits (Japanese white rabbit) for infest-ing ticks. Five hundreds of R. microplus larvae were exposed to each animal (3 animals/host species). Tick recoveries were 11.0%, 0.47%, and 5.5% from cattle, sheep, and rabbits, respectively. The averages of tick feeding periods were not significantly different on cattle, sheep, and rabbits, 28.8, 25.3, and 26.7 days, respectively. The average weights of individual engorged female from cattle, sheep, and rabbits were 312.5, 219.1, and 130.2 mg, respectively and those of egg mass weights each to 85.0, 96.6, and 17.8 mg. The highest egg hatching rate was in the ticks from cattle (96.0%), fol-lowed by those from rabbits (83.0%) and sheep (19.2%). These data suggest that rabbits could be as an alternative host to cultivate R. microplus for evaluating vaccines and chemical and biological medicines against the tick in the laboratory, although the biological parameters of ticks were less than those from cattle.     

澳大利亚萨福克羊及无角陶塞特羊对新疆的生态适应性及杂交后代利用研究

测定分析了新疆地区引入澳大利亚萨福克羊及无角陶塞特羊的体温、脉搏、呼吸频率、血清T₃、T₄含量、繁殖率、总适应能力及杂一代公羔的育肥屠宰性能.结果表明,萨福克羊及无角陶塞特羊繁殖率及体重接近或超过原产地澳大利亚的生产水平.萨福克羊总适应能力为98.80%,无角陶赛特羊为98.74%.杂一代公羔日增重、饲料转化率、净肉重较哈萨克羊高,而尾脂重低于哈萨克羊.     

澳大利亚萨福克羊及无角陶塞特羊对新疆的生态适应性及杂交后代利用研究

测量分析了新疆地区引入澳大利亚萨福克羊及无角陶塞特羊的体温、脉搏、呼吸频率、血清T3、T4含量、繁殖率、总适应能力及杂一代公羔的育肥屠宰性能,结果表明,萨福克羊及无角陶塞特羊繁殖率及体重接近或超过原产地澳大利亚的生产水平,萨福克羊总适应能力为98.80%,无角陶塞特羊为98.74%,杂一代公羔日增重、饲料转化率、净肉重较哈萨克羊高,而尾脂重低于哈萨克羊。     

The Tissue Distribution and Developmental Changes of ghrelin mRNA Expression in Sheep

Male Kazak sheep and Xinjiang fine wool sheep, six for each different age group (days 2, 30, 60, 90 and 120), were used in the present study to investigate the tissue distribution and developmental changes of ghrelin mRNA expression in abomasum; however, there was no 120-day-old Kazak sheep. After measurement of body weight, the tissues such as hypothalamus, pituitary, heart, liver, rumen, reticulum, omasum, abomasum, duodenum, and longissimus dorsi muscle were sampled. And the total RNA of different tissues was extracted to determine the abundance of ghrelin mRNA by RT-PCR and real-time PCR. The results showed that (1) for both breeds, body weight among different ages was significantly different (P<0.05). And from day 30 to 90, the body weight of Kazak was significantly higher than that of Xinjiang (P<0.01); (2) Ghrelin mRNA existed in all the above tissues and was significantly higher in the abomasum than in other tissues (P<0.05); (3) the temporal patterns of abomasum ghrelin mRNA expression in Kazak and Xinjiang were similar. From day 2 to 60 in Kazak and 2 to 90 in Xinjiang, there was a steady increase in the ghrelin mRNA level. By day 60 in Kazak and day 90 in Xinjiang, the level reached a plateau and remained steady. These results also demonstrated that from birth to day 90, ghrelin mRNA level was significantly higher in Kazak than in Xinjiang (P<0.01).     

Sheep lymphocyte antigens: A preliminary study

Sera from 287 sheep were screened for cytotoxic antibodies against sheep lymphocytes. Forty four antisera were selected which provisionally define 13 lymphocyte antigens. The frequency of these antigens was studied in 305 sheep from 8 flocks of different breeds. Family studies confirm that inheritance of sheep lymphocyte antigens is controlled by the autosomal codominant genes of at least 2 linked loci.     

Mitochondrial analysis sheds light on the origin of hair sheep

A total of 180 mtDNA sequences from hair Caribbean (93), West African (73) and Canarian‐wooled (14) sheep were analysed to shed light on the origin of hair sheep. A comparison of 360 Iberian sheep sequences retrieved from GenBank was performed to assess a possible European origin of the Caribbean hair sheep. These 180 sequences gave 48 different haplotypes (16 in Caribbean sheep). All Caribbean and Canarian‐wooled sequences and 91.8% of the West African samples belonged to haplogroup B. The sheep analysed showed wide haplotypic identity. Caribbean sheep shared roughly two‐thirds of their samples with Canarian‐wooled and West African samples, respectively. Principal component analysis showed that the Caribbean and the Canarian‐wooled sheep clustered together. Additional analyses showed that hair and Iberian sheep had wide genetic identity. It was not possible to ascertain a single Canarian, African or European origin of the Caribbean hair sheep using mtDNA markers only. European, African and Caribbean hair sheep maternal genetic backgrounds likely result from related domestication events.     

Multivariate characterization of morphological traits in Burkina Faso sheep

A total of 6440 female sheep from Burkina Faso were scored for seven body measurements and four qualitative morphological traits. Sampling included the three main environmental areas and sheep breeds of Burkina Faso: the Sahel area (Burkina-Sahel sheep), the Sudan-Sahel area (Mossi sheep) and the Sudan area (Djallonké sheep). Canonical analyses showed that differences in body measurements between the Sudan and the Sudan-Sahel sheep were small even though most body traits showed higher average values in the Burkina-Sahel sheep: the shortest Mahalanobis distance was found between the Sudan and the Sudan-Sahel populations (1.54), whilst that between the Sudan and the Sahelian populations was the largest (7.88). Discriminant analysis showed that most Sudan (Djallonké) individuals (60.85%) were classified as Sudan-Sahel (Mossi) individuals whilst most Burkina-Sahel individuals were classified into their environmental area of sampling (89.46%). Correspondence analyses indicated that the Burkina-Sahel sheep population clustered together with dropping ears, black and brown colour patterns and presence of wattles, the Sudan sheep were closely associated with long hair and vertical and curled ears and that the Sudan-Sahel sheep did not have clear associations with qualitative phenotypic traits. At the morphological level, the Sudan-Sahel (Mossi) sheep population can be considered a geographical subpopulation belonging to the Djallonké breed, showing some particularities, namely larger body size, due to the particular environmental condition of the area in which it is managed and a continuous gene flow from Sahelian sheep, The information reported in this study will be the basis for the establishment of further characterization, conservation and selection strategies for Burkina Faso sheep.     

Prevalence of Cystic Echinococcosis in Slaughtered Sheep as an Indicator to Assess Control Progress in Emin County,Xinjiang, China

Hydatid disease imposing serious threat on human health and great loss in live¬stock pastoralism remains a major public health problem in western China. To assess and monitor the effect of control program on transmission dynamics, we used the prevalence of cystic echinococcosis in slaughtered sheep at slaughterhouse as an indicator during the period of 2007 to 2013 in Emin County, Xinjiang Uygur Autonomous Region, China. The results showed a significant decline trend of prevalence in all age groups during the 7 years when the control program was implemented; particularly, the rate was reduced by 72% after first 3 years. Among the sheep slaughtered, the age distribution evidenced that the prevalence increased significantly as the sheep grew older. The baseline data indicated that the rate was 4.5% at the age <1, 6.7% at age 2~, and reached to the highest 17.9% at age ≥4 years. Earlier response to the intervention pressure was seen in the sheep at the younger age. Significant decline started from 2008 at the age <1, from 2009 at age of 1~, 2010 at 2~ to 3~, and the latest, in 2012 at age ≥4. This study demonstrated that the prevalence of cystic echinococcosis in slaughtered sheep may be used as an indicator to assess and monitor the transmission status during and after control program providing information for betterment of performance to sustain control strength.     

A missense mutation in AGTPBP1 was identified in sheep with a lower motor neuron disease

A type of lower motor neuron (LMN) disease inherited as autosomal recessive in Romney sheep was characterized with normal appearance at birth, but with progressive weakness and tetraparesis after the first week of life. Here, we carried out genome-wide homozygosity mapping using Illumina Ovine SNP50 BeadChips on lambs descended from one carrier ram, including 19 sheep diagnosed as affected and 11 of their parents that were therefore known carriers. A homozygous region of 136 consecutive single-nucleotide polymorphism (SNP) loci on chromosome 2 was common to all affected sheep and it was the basis for searching for the positional candidate genes. Other homozygous regions shared by all affected sheep spanned eight or fewer SNP loci. The 136-SNP region contained the sheep ATP/GTP-binding protein 1 (AGTPBP1) gene. Mutations in this gene have been shown to be related to Purkinje cell degeneration (pcd) phenotypes including ataxia in mice. One missense mutation c.2909G>C on exon 21 of AGTPBP1 was discovered, which induces an Arg to Pro substitution (p.Arg970Pro) at amino-acid 970, a conserved residue for the catalytic activity of AGTPBP1. Genotyping of this mutation showed 100% concordant rate with the recessive pattern of inheritance in affected, carrier, phenotypically normal and unrelated normal individuals. This is the first report showing a mutant AGTPBP1 is associated with a LMN disease in a large mammal animal model. Our finding raises the possibility of human patients with the same etiology caused by this gene or other genes in the same pathway of neuronal development.     

Genetic structure and admixture in sheep from terminal breeds in the United States

Selection for performance in diverse production settings has resulted in variation across sheep breeds worldwide. Although sheep are an important species to the United States, the current genetic relationship among many terminal sire breeds is not well characterized. Suffolk, Hampshire, Shropshire and Oxford (terminal) and Rambouillet (dual purpose) sheep (n = 248) sampled from different flocks were genotyped using the Applied Biosystems Axiom Ovine Genotyping Array (50K), and additional Shropshire sheep (n = 26) using the Illumina Ovine SNP50 BeadChip. Relationships were investigated by calculating observed heterozygosity, inbreeding coefficients, eigenvalues, pairwise Wright’s F_ST estimates and an identity by state matrix. The mean observed heterozygosity for each breed ranged from 0.30 to 0.35 and was consistent with data reported in other US and Australian sheep. Suffolk from two different regions of the United States (Midwest and West) clustered separately in eigenvalue plots and the rectangular cladogram. Further, divergence was detected between Suffolk from different regions with Wright’s F_ST estimate. Shropshire animals showed the greatest divergence from other terminal breeds in this study. Admixture between breeds was examined using admixture , and based on cross-validation estimates, the best fit number of populations (clusters) was K = 6. The greatest admixture was observed within Hampshire, Suffolk, and Shropshire breeds. When plotting eigenvalues, US terminal breeds clustered separately in comparison with sheep from other locations of the world. Understanding the genetic relationships between terminal sire breeds in sheep will inform us about the potential applicability of markers derived in one breed to other breeds based on relatedness.     

Characterization and linkage mapping often sheep microsatellite markers derived from a sheep x hamster cell hybrid

A cosmid library has been constructed from a sheep x hamster cell hybrid containing sheep chromosome t₁, rob (6;24). Clones containing sheep DNA were identified by hybridizing to a total sheep genomic DNA probe. Small fragments (<500 bp) containing (AC)_n microsatellites were subcloned and sequenced. Ten microsatellite markers were characterized and six were mapped back to chromosomes 6 and 24. The remaining microsatellites mapped to chromosome 26, which was shown to be present in a small proportion of cells of the cell line.     

Mitochondrial diversity and the origin of Iberian sheep

Mitochondrial DNA diversity was analysed in 19 Iberian and six foreign sheep breeds. Three mtDNA lineages (B, A and C) were found in the Iberian sheep, with type B clearly predominating over the others. The results were analysed for each of the morphologically determined breed groups in Iberian sheep: Merino, Entrefino, Churro and Iberian trunks. MtDNA lineage C was found only in the Iberian trunk composed of Montesina and Ojalada. These two populations had high mtDNA variability, and in the Iberian sheep only Merino Branco had more variation. The other three Merino types studied showed moderate variability, including the most authentic Merino, the Spanish Merino. These three Merinos clustered closely in a multidimensional scaling representation of distances, while the fourth breed (Merino Branco) showed a clear separation. As for the other two trunks, breeds from the Churro group showed greater maternal uniformity while results for populations included in the so-called Entrefino trunk seemed to have a more heterogeneous maternal origin. The results obtained are discussed with available data from nuclear markers and with morphological classifications, and all this information is analysed in relation to the origin of the different Iberian sheep breeds.     

我国主要地方绵羊品种随机扩增多态DNA研究

对蒙古羊、湖羊、滩羊、小尾寒羊、乌珠穆沁羊、藏绵羊、阿勒泰羊7个地方绵羊品种和无角陶赛特羊、德国美利奴羊、萨福克羊3个引入品种基因组DNA进行了RAPD分析。结果表明：（1）RAPD可作为一种有效的标记用于绵羊品种之间遗传亲缘关系的分析。（2）在所使用的43种随机引物中,有35种引物扩增出多态谱带,多态频率为66.24%,说明RAPD技术用于研究绵羊核DNA的遗传变异具有较高的检出率和灵敏度。（3）总群体平均遗传多样性指数（HSP)为0.9139,说明绵羊群体具有较为丰富的遗传多样性。（4）我国地方绵羊品种间的分子聚类关系与其所处的地理位置、考古学结果,以及细胞遗传学研究结果基本,引入品种间的分子聚类关系也与其育成史基本一致。     

Phylogenetic Relationships of Sheep Populations from Coastal Areas in East Asia

Using the method of random sampling in typical colonies of the central area of the habitat and several electrophoresis techniques, the variations of 12 structural loci encoding blood protein of 60 Small-tailed Han sheep were examined and compared with those of four other sheep populations from coastal areas in East Asia to explore their phylogenetic relationships. Average heterozygosity of the five populations was: Kharkhorin sheep 0.3447, Ulaanbaatar sheep 0.3285, Small-tailed Han sheep 0.3157, Hu sheep 0.3884, and Cham Tribe sheep 0.2300. The earlier researchers' conclusion through documentary research, indicating that Small-tailed Han sheep and Hu sheep both evolved from Mongolian sheep, was further verified by the results of this study. Hu sheep, Small-tailed Han sheep, and Cham Tribe sheep were decreasingly affected by the bloodline of Mongolian sheep. A partial founder population, i.e., Mongolian sheep forming current Small-tailed Han sheep, possibly made a contribution to the bloodline of Cham Tribe sheep.     

QTL mapping for sexually dimorphic fitness-related traits in wild bighorn sheep

Dissecting the genetic architecture of fitness-related traits in wild populations is key to understanding evolution and the mechanisms maintaining adaptive genetic variation. We took advantage of a recently developed genetic linkage map and phenotypic information from wild pedigreed individuals from Ram Mountain, Alberta, Canada, to study the genetic architecture of ecologically important traits (horn volume, length, base circumference and body mass) in bighorn sheep. In addition to estimating sex-specific and cross-sex quantitative genetic parameters, we tested for the presence of quantitative trait loci (QTLs), colocalization of QTLs between bighorn sheep and domestic sheep, and sex × QTL interactions. All traits showed significant additive genetic variance and genetic correlations tended to be positive. Linkage analysis based on 241 microsatellite loci typed in 310 pedigreed animals resulted in no significant and five suggestive QTLs (four for horn dimension on chromosomes 1, 18 and 23, and one for body mass on chromosome 26) using genome-wide significance thresholds (Logarithm of odds (LOD) >3.31 and >1.88, respectively). We also confirmed the presence of a horn dimension QTL in bighorn sheep at the only position known to contain a similar QTL in domestic sheep (on chromosome 10 near the horns locus; nominal P<0.01) and highlighted a number of regions potentially containing weight-related QTLs in both species. As expected for sexually dimorphic traits involved in male-male combat, loci with sex-specific effects were detected. This study lays the foundation for future work on adaptive genetic variation and the evolutionary dynamics of sexually dimorphic traits in bighorn sheep.