首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
  1. We reviewed data on the diets of mouflon (Mediterranean island populations Ovis gmelini musimon and introduced hybridized populations Ovis gmelini musimon × Ovis sp.) from 33 field studies (comprising 51 independent data points suitable for analysis) to detect general patterns in the botanical composition of the diet and identify ecological factors explaining its variation. We expected mouflon, generally classified as grazers, to include botanical entities other than grass in their diet, especially when they are forced to do so by low resource availability, and in certain seasons.
  2. Diet composition was investigated based on samples of rumen content and faeces. We combined these data with environmental characteristics at each site using a co‐inertia analysis.
  3. As expected, grass often constituted the highest proportion in the diet (in 28 of the 51 data points) and represented on average 35% (range = 0–91%) of mouflon diet, confirming the importance of this food for the species. However, referring strictly to commonly used thresholds (>75% or >90%) shows that the classification of mouflon as grazers could be questioned. Indeed, forbs and shrubs constituted 24% (range: 0–93%) and 16% (range: 0–55%) of their diet, respectively, so that mouflon should at least be considered as variable grazers. Forbs represented a high percentage of the overall diet in the Kerguelen Archipelago, southern Indian Ocean (autumn and winter: 73%) and Teide National Park, Canary Islands, Spain (autumn and winter: 83%), whereas shrubs represented a high proportion of the overall diet in Mediterranean areas (19%).
  4. Diet composition varied with spatio‐temporal variation in forage availability (documented as habitat related or seasonal variation), confirming that mouflon are able to feed on a large variety of plants.
  5. Further investigations concerning both digestive morphology and consequences of the inclusion of browse in the diet on population dynamics of mouflon are needed to understand the persistence of this species over a wide range of habitats despite a potential mismatch between its digestive ability and its observed diet.
  相似文献   

2.
A comparison of theβ A- andβ B-globin gene clusters of sheep   总被引:2,自引:1,他引:2  
Domestic sheep have two common alleles at the adult beta-globin locus, beta A and beta B. Here we report the structure of the beta-globin locus of A-haplotype sheep. The locus consists of 12 genes, organized as a triplicated 4-gene set: 5' epsilon 1-epsilon II-psi beta I-beta C-epsilon III-epsilon IV-psi beta II-beta A-epsilon V-epsilon VI-psi beta III-beta F 3'. This arrangement is identical to that of the closely related goat locus. Sheep with the B haplotype have a locus arrangement consisting of a duplicated four-gene set, lacking the beta C gene as well as three other genes present in A sheep and goats. In order to understand the evolutionary history of the B sheep locus, we have sequenced the beta B gene from these sheep, and the beta C gene from A-haplotype sheep, and compared the sequences to those of the sheep beta A, goat beta C, and beta A, and cow adult beta genes. Our results indicate that the beta B gene has diverged recently from the beta A gene, and therefore the beta B locus structure may have resulted from a recent deletion from a triplicated locus.  相似文献   

3.
4.
Prevalence and incidence of foot rot disease in free-ranging and captive bovine wild ruminant populations are increasing worldwide. Even species in which the disease has not been described in the past are presently affected by the co-working pathogens Dichelobacter nodosus and Fusobacterium necrophorum. This paper discusses disease control measures and the expense for a successful treatment of affected populations of mouflon. The rationale and perspectives of treating foot rot disease in wild mouflons are discussed.  相似文献   

5.
Summary DNA analysis of the - and -globin gene clusters has revealed substantial variability between individuals and populations. As well as restriction enzyme site and length polymorphisms, variation in gene copy number and type is observed. Because of this extensive polymorphism DNA analysis offers a highly informative method of studying genetic affinities between human populations. Haplotypes, consisting of a set of restriction enzyme polymorphisms distributed along the cluster, have been developed for both loci. Analysis of the molecular basis of numerous -thalassaemia alleles has revealed, in general, different sets of mutations in different populations, indicating that these postdate the racial divergence. Recent microepidemiological studies on the distribution of -thalassaemia support the hypothesis that this condition, like the {ie16-1}, has been selected because it confers protection against malaria. Population-specific DNA polymorphisms at these and other loci promise to be of considerable value to genetic anthropology.  相似文献   

6.
The arrangement of primate β-related globin genes has been determined by restriction endonuclease mapping of genomic DNA from species ranging from prosimians to man. The arrangement of the entire ?γγδβ-globin gene cluster in the gorilla and the yellow baboon is indistinguishable from that of man. Restriction site differences between these species are consistent with a surprisingly low overall rate of intergenic DNA sequence divergence of approximately 1% in 5 million years. A new world monkey (owl monkey) has a single γ-globin gene, suggesting that the Gγ-Aγ-globin gene duplication in man is ancient, and occurred about 20 to 40 million years ago. The β-globin gene cluster in the brown lemur, a prosimian, is remarkably short (about 20,000 base-pairs) and contains single ?-, γ- and β-globin genes. The γ- and β-globin genes in this animal are separated by a curious gene containing the 3′ end of a β-globin gene preceded by sequences related to the 5′ end of the ?-globin gene.  相似文献   

7.
8.
A physical map of the DNA regions flanking the rabbit β-globin gene   总被引:1,自引:0,他引:1  
A.J. Jeffreys  R.A. Flavell 《Cell》1977,12(2):429-439
  相似文献   

9.
The globin gene clusters of Xenopus laevis are interspersed by various different repetitive DNA elements. A specific repeat, the JH12 element, has been mapped by Southern analysis and some of its locations have been subsequently confirmed by nucleotide sequencing. JH12 family members seem to represent mobile genetic elements and display a high degree of divergence. The nucleotide sequences upstream to the adult I-globin gene and to the two coordinately expressed larval I- and II genes have been determined and compared to those of the adult -genes. Besides some repetitive DNA elements and a short sequence of rather weak homology we have found no characteristic sequence motifs to be common to the adult - and -genes. The two larval -genes share one short sequence element being absent from the adult genes. This might reflect completely different sequence requirements for protein interactions and for the regulation of adult and larval globin gene expression.  相似文献   

10.
β-Catenin is an evolutionarily conserved molecule that functions as a crucial effector in both cell-to-cell adhesion and Wnt signaling. To gain a better understanding of its role in the development of hair follicles, we cloned the cDNA sequence of the β-catenin gene from the skin of Aohan fine-wool sheep and performed a variety of bioinformatics analyses. We obtained the full-length sequence, which was 4573-bp long and contained a 2346-bp open reading frame encoding a protein of 781 amino acids. The protein had a predicted molecular weight of 85.4 kDa and a theoretical isoelectric point of 5.57. Domain architecture analysis of the β-catenin protein revealed an armadillo repeat region, which is a common feature of β-catenin in other species. The ovine β-catenin gene shares 97.91%, 94.25%, 94.59%, 83.89%, and 89.39% sequence identity with its homologs in Bos taurus, Homo sapiens, Sus scrofa, Gallus gallus, and Mus musculus, respectively, while the amino acid sequence is more than 99% identical with each of these species. The expression of β-catenin mRNA was detected in the heart, liver, spleen, lung, kidney, skin, muscle, and adipose tissue. Expression levels were maximal in the lung and minimal in the muscle, and the difference in expression in these tissues was significant (P < 0.01). Western blot analysis revealed the presence of the β-catenin protein in all tissues examined; expression was lowest in the skin and adipose tissues.  相似文献   

11.
A hemoglobin C chain has been detected in anemic Moufflon and in anemic Barbary sheep. Results of limited structural studies suggest that these C chains are closely related to the C chains which are produced in the domestic sheep and goat during experimental anemia and rather different from the C chain of certain nonanemic Barbary sheep. The structural variability among the chains of some nonanemic Caprini species is greater than that observed for the C chains of the same animals.This research was supported in part by United States Public Health Service Research grant HE-05168.  相似文献   

12.
DNA samples obtained from 8 goats, 1 moufflon, and 84 sheep with HbA, HbAB, and HbB belonging to different breeds were digested withBamHI,EcoRI,HindIII andPstI and probed with the 5 end of the goat IV- and Z-globin genes. Sheep homozygous for HbA show a different restriction pattern than sheep homozygous for HbB with each of these endonucleases. The main differences is that HbB sheep lack the H and X genes. These results, in addition to those previously obtained using a probe specific for -globin genes, suggest that HbB sheep probably lack the preadult four-gene set. The DNAs from moufflon and sheep homozygous for HbA show indistinguishable restriction patterns. Furthermore, a number of restriction fragment length polymorphisms (RFLPs) are detected in the IV and Z DNA regions, and oneHindIII RFLP in the VI DNA region.This work was supported by the Ministero della Pubblica Istruzione and, in part, by the Consiglio Nazionale delle Ricerche.  相似文献   

13.
14.
The production of clavam metabolites has been studied previously in Streptomyces clavuligerus , a species that produces clavulanic acid as well as 4 other clavam compounds, but the late steps of the pathway leading to the specific end products are unclear. The present study compared the clavam biosynthetic gene cluster in Streptomyces antibioticus , chosen because it produces only 2 clavam metabolites and no clavulanic acid, with that of S.?clavuligerus. A cosmid library of S.?antibioticus genomic DNA was screened with a clavaminate synthase-specific probe based on the corresponding genes from S. clavuligerus, and 1 of the hybridizing cosmids was sequenced in full. A clavam gene cluster was identified that shows similarities to that of S.?clavuligerus but also contains a number of novel genes. Knock-out mutation of the clavaminate synthase gene abolished clavam production in S.?antibioticus, confirming the identity of the gene cluster. Knock-out mutation of a novel gene encoding an apparent oxidoreductase also abolished clavam production. A potential clavam biosynthetic pathway consistent with the genes in the cluster and the metabolites produced by S. antibioticus, and correspondingly different from that of S.?clavuligerus, is proposed.  相似文献   

15.
We have determined the entire nucleotide sequence of a cloned β-globinmaj gene derived from the BALB/c mouse. This sequence is 1567 bases long and includes the 5′ cap region as well as the presumptive poly(A) addition site of β-globin mRNA. The sequence establishes the fact that the gene is encoded in three discontinuous segments of DNA interrupted by two intervening sequences and precisely locates each. The smaller intervening sequence, 116 bases long, occurs between Arg and Leu codons at codon positions 30 and 31. The larger intervening sequence of 646 bases also occurs between Arg and Leu codons, but at codon positions 104 and 105. There is striking homology between the borders of the two intervening sequences, but no extensive dyad symmetry. Furthermore, the DNA region that just precedes and overlaps the 5′ cap structure of the mRNA shows homology to corresponding regions in other eucaryotic genes including the late adenovirus promoter. The 3′ untranslated sequence is closely homologous to that of the rabbit β-globin mRNA. The sequence thus allows us to identify several noncoding regions of potential importance for the expression and processing of genetic information. It also provides a basis for future comparison with other sequenced genes and a defined substrate for the development of direct tests of gene function.  相似文献   

16.
17.
18.
Sequence polymorphisms within the 5HS2 segment of human locus control region is described among sickle cell anemia patients. Distinct polymorphic patterns of a simple sequence repeat are observed in strong linkage disequilibrium with each of the five major S haplotypes. Potential functional relevance of this polymorphic region in globin gene expression is discussed.  相似文献   

19.
The structure of the beta chain of adult bovine hemoglobin Bali of the Bali cattle was determined and compared to those of beta A, beta B, and other beta-chain variants of domestic cattle reported previously. The lysine residue at beta A18 was substituted by histidine in beta Bali18. This change requires two base substitutions at the codon and is also found in beta B18. The beta B chain differs from the beta A chain at residue Nos. 15, 18, and 119. It was concluded that a common ancestor of the beta B and beta Bali first diverged from the beta A chain through the Lys leads to His substitution. This fact indicates that the high degree of dimorphism of the beta A and beta B chains in Indian humped cattle is a result of its hybrid origin. An evolutionary tree for the bovine hemoglobin beta-chain variants was constructed based on parsimonious evolution and homology with related species.  相似文献   

20.
-globin gene haplotypes were determined for 196 normal (-A) and 419 thalassaemia (-Th) chromosomes of individuals from four different regions of the Indian subcontinent; North-west Pakistan, Gujarat, Punjab and Sindh. Analysis of -A and -Th haplotypes and haplotype-mutation associations in each regional group along with a consideration of Indian history provided information about the origin and spread of -thalassaemia mutations on the Indian subcontinent. The data are consistent with relatively recent and local origins for most -thalassaemia mutations. The frequencies of particular alleles differ markedly in various regions and these may be useful population markers. Of the high frequency alleles, intervening sequence 1 (IVS-1) nucleotide 5 (G-C) and codons 41/42 (-CTTT) appear to be older as suggested by multiple haplotype associations and a widespread geographical distribution. The microepidemiology of -thalassaemia in this region reflects considerable ethnic diversity, gene flow from population migration and natural selection by malaria infection.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号