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1.

Background  

In East Africa, foot-and-mouth disease virus serotype SAT 1 is responsible for occasional severe outbreaks in livestock and is known to be maintained within the buffalo populations. Little is known about the evolutionary forces underlying its epidemiology in the region. To enhance our appreciation of the epidemiological status of serotype SAT 1 virus in the region, we inferred its evolutionary and phylogeographic history by means of genealogy-based coalescent methods using 53 VP1 coding sequences covering a sampling period from 1948-2007.  相似文献   

2.
To investigate the foot-and-mouth disease virus (FMDV) serotypes circulating in Uganda’s cattle population, both serological and virological analyses of samples from outbreaks that occurred during 2012–2013 were performed. Altogether, 79 sera and 60 oropharyngeal fluid (OP)/tissue/oral swab samples were collected from herds with reported FMD outbreaks in seven different Ugandan districts. Overall, 61/79 (77%) of the cattle sera were positive for antibodies against FMDV by PrioCHECK FMDV NS ELISA and solid phase blocking ELISA detected titres ≥ 80 for serotypes O, SAT 1, SAT 2 and SAT 3 in 41, 45, 30 and 45 of these 61 seropositive samples, respectively. Virus neutralisation tests detected the highest levels of neutralising antibodies (titres ≥ 45) against serotype O in the herds from Kween and Rakai districts, against SAT 1 in the herd from Nwoya district and against SAT 2 in the herds from Kiruhura, Isingiro and Ntungamo districts. The isolation of a SAT 2 FMDV from Isingiro was consistent with the detection of high levels of neutralising antibodies against SAT 2; sequencing (for the VP1 coding region) indicated that this virus belonged to lineage I within this serotype, like the currently used vaccine strain. From the Wakiso district 11 tissue/swab samples were collected; serotype A FMDV, genotype Africa (G-I), was isolated from the epithelial samples. This study shows that within a period of less than one year, FMD outbreaks in Uganda were caused by four different serotypes namely O, A, SAT 1 and SAT 2. Therefore, to enhance the control of FMD in Uganda, there is need for efficient and timely determination of outbreak virus strains/serotypes and vaccine matching. The value of incorporating serotype A antigen into the imported vaccines along with the current serotype O, SAT 1 and SAT 2 strains should be considered.  相似文献   

3.

Background

To study the role of African buffalos (Syncerus caffer) in the maintenance of foot-and-mouth disease in Uganda, serum samples were collected from 207 African buffalos, 21 impalas (Aepyceros melampus), 1 giraffe (Giraffa camelopardalis), 1 common eland (Taurotragus oryx), 7 hartebeests (Alcelaphus buselaphus) and 5 waterbucks (Kobus ellipsiprymnus) from four major National Parks in Uganda between 2005 and 2008. Serum samples were screened to detect antibodies against foot-and-mouth disease virus (FMDV) non-structural proteins (NSP) using the Ceditest® FMDV NS ELISA. Solid Phase Blocking ELISAs (SPBE) were used to determine the serotype-specificity of antibodies against the seven serotypes of FMDV among the positive samples. Virus isolation and sequencing were undertaken to identify circulating viruses and determine relatedness between them.

Results

Among the buffalo samples tested, 85% (95% CI = 80-90%) were positive for antibodies against FMDV non-structural proteins while one hartebeest sample out of seven (14.3%; 95% CI = -11.6-40.2%) was the only positive from 35 other wildlife samples from a variety of different species. In the buffalo, high serotype-specific antibody titres (≥ 80) were found against serotypes O (7/27 samples), SAT 1 (23/29 samples), SAT 2 (18/32 samples) and SAT 3 (16/30 samples). Among the samples titrated for antibodies against the four serotypes O, SAT 1, SAT 2 and SAT 3, 17/22 (77%; CI = 59.4-94.6%) had high titres against at least two serotypes.FMDV isolates of serotypes SAT 1 (1 sample) and SAT 2 (2 samples) were obtained from buffalo probang samples collected in Queen Elizabeth National Park (QENP) in 2007. Sequence analysis and comparison of VP1 coding sequences showed that the SAT 1 isolate belonged to topotype IV while the SAT 2 isolates belonged to different lineages within the East African topotype X.

Conclusions

Consistent detection of high antibody titres in buffalos supports the view that African buffalos play an important role in the maintenance of FMDV infection within National Parks in Uganda. Both SAT 1 and SAT 2 viruses were isolated, and serological data indicate that it is also likely that FMDV serotypes O and SAT 3 may be present in the buffalo population. Detailed studies should be undertaken to define further the role of wildlife in the epidemiology of FMDV in East Africa.
  相似文献   

4.
Genetic studies concerned with the demographic history of wildlife species can help elucidate the role of climate change and other forces such as human activity in shaping patterns of divergence and distribution. The African buffalo (Syncerus caffer) declined dramatically during the rinderpest pandemic in the late 1800s, but little is known about the earlier demographic history of the species. We analysed genetic variation at 17 microsatellite loci and a 302‐bp fragment of the mitochondrial DNA control region to infer past demographic changes in buffalo populations from East Africa. Two Bayesian coalescent‐based methods as well as traditional bottleneck tests were applied to infer detailed dynamics in buffalo demographic history. No clear genetic signature of population declines related to the rinderpest pandemic could be detected. However, Bayesian coalescent modelling detected a strong signal of African buffalo population declines in the order of 75–98%, starting in the mid‐Holocene (approximately 3–7000 years ago). The signature of decline was remarkably consistent using two different coalescent‐based methods and two types of molecular markers. Exploratory analyses involving various prior assumptions did not seriously affect the magnitude or timing of the inferred population decline. Climate data show that tropical Africa experienced a pronounced transition to a drier climate approximately 4500 years ago, concurrent with the buffalo decline. We therefore propose that the mid‐Holocene aridification of East Africa caused a major decline in the effective population size of the buffalo, a species reliant on moist savannah habitat for its existence.  相似文献   

5.
Water buffalo (Bubalus bubalis), a large‐sized member of the Bovidae family, is considered as an important livestock species throughout Southeast Asia. In order to better understand the molecular basis of buffalo improvement and breeding, we sequenced and assembled the genome (2n=50) of a river buffalo species Bubalus bubalis from Bangladesh. Its genome size is 2.77 Gb, with a contig N50 of 25 kb and the scaffold N50 of 6.9 Mbp. Based on the assembled genome, we annotated 24,613 genes for future functional genomics studies. Phylogenetic tree analysis of cattle and water buffalo lineages showed that they diverged about 5.8–9.8 million years ago. Our findings provide an insight into the water buffalo genome which will contribute in further research on buffalo such as molecular breeding, understanding complex traits, conservation, and biodiversity.  相似文献   

6.
Interspecies hybridization of bovids occurs between domestic cattle and at least three other species; American bison (Bison bison), yak (Bos grunniens) and banteng (Bos banteng). Birth of a cattle × buffalo (Bubalus bubalis) hybrid has reportedly occurred in Russia and in China, but these reports were not authenticated. Such hybrids could be important in improving livestock production and management of diseases that impede production in tropical Africa. This study investigated hybridization between cattle and its closest African wild bovid relative, the African buffalo (Syncerus caffer caffer). In an attempt to produce cattle × buffalo hybrid embryos in vitro, matured cattle oocytes were subjected to a standard in vitro fertilization (IVF) procedure with either homologous cattle (n = 1166 oocytes) or heterologous African buffalo (n = 1202 oocytes) frozen-thawed epididymal sperm. After IVF, 67.2% of the oocytes inseminated with the homologous cattle sperm cleaved. In contrast, fertilization with buffalo sperm resulted in only a 4.6% cleavage rate. The cleavage intervals were also slower in hybrid embryos than in the IVF-derived cattle embryos. Of the cleaved homologous cattle embryos 52.2% progressed to the morula stage compared with 12.7% for the buffalo hybrid embryos. No hybrid embryos developed beyond the early morula stage, while 40.1% of the cleaved cattle × cattle embryos developed to the blastocyst stage. Transfer of buffalo hybrid IVF embryos to domestic cattle surrogates resulted in no pregnancies at 60 days post-transfer. This study indicates that interspecies fertilization of cattle oocytes with African buffalo epididymal sperm can occur in vitro, and that a barrier to hybridization occurs in the early stages of embryonic development. Chromosomal disparity is likely the cause of the fertilization abnormalities, abnormal development and subsequent arrest impairing the formation of hybrid embryos beyond the early morula stage. Transfer of the buffalo hybrid embryos did not rescue the embryos from development arrest.  相似文献   

7.
Two foot-and-mouth disease virus (FMDV) genome sequences have been determined for isolates collected from recent field outbreaks in North Africa (Egypt) and the Middle East (Palestinian Autonomous Territories). These data represent the first examples of complete genomic sequences for the FMDV SAT 2 topotype VII, which is thought to be endemic in countries immediately to the south of the Sahara desert. Further studies are now urgently required to provide insights into the epidemiological links between these outbreaks and to define the pathogenicity of this emerging lineage.  相似文献   

8.
Foot-and-mouth disease (FMD) is a highly contagious, viral disease that affects most ruminant and porcine species, and periodic outbreaks on Mongolia's Eastern Steppe affect Mongolian gazelles (Procapra gutturosa) and livestock. During 2005-08, we collected sera from 36 and 57 calf and adult gazelles, respectively, and from adult domestic animals sympatric with the gazelles, including 138 sheep (Ovis aries), 140 goats (Capra aegagrus hircus), 139 Bactrian camels (Camelus bactrianus), and 138 cattle (Bos taurus). Our goal was to determine whether the prevalence of the antibody to foot-and-mouth disease virus (FMDV) in gazelles declined relative to previous estimates in the absence of FMD outbreaks. Overall, 2.0% (95% CI 0.7-3.3%, n=555) of the four livestock species were antibody-positive for nonstructural proteins of FMDV (FMDV-NS), whereas 30.3% (95% CI 26.5-34.1%, n=555) had antibodies for structural proteins (i.e., vaccination-derived antibodies). Seven of 57 free-ranging gazelle calves (7.5%, 95%CI 1.6-12.4%) were FMDV-NS positive. None of 36 adult gazelles sampled in 2008 were antibody-positive for exposure to FMDV, indicating a significant decline (χ(2)=18.99; P<0.001; df=1) in antibody prevalence among gazelles from the same area during a livestock outbreak in 2001. The episodic nature of FMD outbreaks on the Eastern Steppe, Mongolia, with evidence of FMDV exposure in gazelles only during or following concurrent outbreaks in livestock, suggests that FMDV may spill over into the gazelle population during livestock outbreaks and that successful control of FMD on the Eastern Steppe requires a focus on control in livestock populations through vaccination.  相似文献   

9.
Mechanisms of speciation of flightless grasshoppers in mountainous and coastal East Africa are inferred considering (i) phylogenies estimated with a combination of molecular markers (16S rRNA locus, COI and H3), (ii) ecological data and (iii) the geographic distribution of Parepistaurus species. The study suggests that coastal taxa of Parepistaurus belong to ancestral lineages from which evolved the high diversity of species found in the Eastern Arc Mountains of Tanzania and Kenya, which are geologically ancient mountain formations. Network analyses and a molecular clock approach, calibrated with the geological age of the volcanoes, suggested that speciation was boosted by climatic fluctuations affecting large areas of East Africa. With the aridification beginning 2.8 Ma, forest taxa were isolated due to forest fragmentation and populations were separated by extended grasslands, which are avoided by Parepistaurus species. However, a humid period between 2.7 and 2.5 Ma triggered a spread of coastal taxa along the Eastern Arc Mountains. Forests expanded again and riparian vegetation along rivers draining into the Indian Ocean probably served as corridors for the dispersal of coastal taxa to the hinterland. The inland volcanoes such as Mount Kilimanjaro are therefore good time markers because their geological age is known, limiting the available time for speciation processes of mountainous Parepistaurus in the area to a maximum of about 1–2 Ma. A third humid but cold period between 1.1 and 0.9 Ma probably further boosted the spread of several flightless and montane‐adapted Orthoptera taxa.  相似文献   

10.
The role of wildlife in the persistence and spread of livestock diseases is difficult to quantify and control. These difficulties are exacerbated when several wildlife species are potentially involved. Bovine tuberculosis (bTB), caused by Mycobacterium bovis, has experienced an ecological shift in Michigan, with spillover from cattle leading to an endemically infected white‐tailed deer (deer) population. It has potentially substantial implications for the health and well‐being of both wildlife and livestock and incurs a significant economic cost to industry and government. Deer are known to act as a reservoir of infection, with evidence of M. bovis transmission to sympatric elk and cattle populations. However, the role of elk in the circulation of M. bovis is uncertain; they are few in number, but range further than deer, so may enable long distance spread. Combining Whole Genome Sequences (WGS) for M. bovis isolates from exceptionally well‐observed populations of elk, deer and cattle with spatiotemporal locations, we use spatial and Bayesian phylogenetic analyses to show strong spatiotemporal admixture of M. bovis isolates. Clustering of bTB in elk and cattle suggests either intraspecies transmission within the two populations, or exposure to a common source. However, there is no support for significant pathogen transfer amongst elk and cattle, and our data are in accordance with existing evidence that interspecies transmission in Michigan is likely only maintained by deer. This study demonstrates the value of whole genome population studies of M. bovis transmission at the wildlife‐livestock interface, providing insights into bTB management in an endemic system.  相似文献   

11.
Foot and Mouth disease (FMD) is a contagious disease leads to economically loss in livestock production all over the world. This serious disease is caused due to the infection of the animal with a single-stranded RNA virus (FMDV). This study aimed to investigate the genetic polymorphism of BoLA-DRB3 gene in Egyptian buffalo as a candidate genetic marker included in multi-factorial process of FMD resistance/susceptibility. Also this work aimed to genetically characterization and serotyping of circulating FMD virus in Egypt during 2016.For serotyping of FMDV, RT-PCR was used for FMDV-positive samples and the results declared the presence of serotype O in all tested animals. The sequence analysis of FMDV samples revealed five different patterns for the detected serotype O which were submitted to GenBank under the accession Nos.: MG017361–MG017365.The 302-bp amplified fragments from BoLA-DRB3 exon 2 were digested with HaeIII endonuclease and the results showed that the presence of five BoLA-DRB3 genotypes, among them the genotype AA might be associated with FMD-resistance (P?<?0.01). On the other hand, genotype AC could be correlated with susceptibility (P?<?0.01) to FMD in Egyptian buffaloes where it was absent in resistant group. The five detected genotypes of BoLA-DRB3 exon 2 were submitted to GenBank with the accession Nos.: MF977316–MF977320. In conclusion, our findings suggested that the detection of different BoLA-DRB3 genotypes may be has a promising role for raising the resistance of Egyptian buffalo against FMDV especially serotype O which is prevalent in Egypt with preferring genotype AA.  相似文献   

12.
DLK1 and CLPG were located in DLK1-GTL2 imprinted cluster. They all affected muscle growth and meat tenderness. The functional importance of DLK1 and CLPG imply that the variation of the genes could affect the growth traits of animal. PCR-SSCP and sequencing were used to analyze the four loci of DLK1 gene and CLPG gene in 1109 individuals, which belong to eight breeds/species of bovidae, including cattle, buffalo and yak. A synonymous mutation (C451T) was detected in exon 5 of DLK1 in Qinchuan cattle, but didn’t change significantly with phenotypic traits. Three genotypes AA, AB and AC of CLPG were identified in Jiaxian cattle. The associations analyst of different genotypes showed that the individuals with genotypes AA and AC had a greater body weight and longer body length than those with genotype AB (P < 0.05 and P < 0.01, respectively); the AA individuals were different from those AB (P < 0.05) in the circumference of cannon bone. No polymorphism was observed in the other populations at other loci. These results were in agreement with the homology analysis: DLK1 and CLPG genes were in a highly conserved.  相似文献   

13.
In order to examine the taxonomic relationship of Theileria sp. of Asian buffalo to the benign Theileria spp. of cattle, we sequenced and compared the major piroplasm protein (p33/34) genes of these parasites. The two consensus sequences determined for the buffalo parasite were of the same length (852 bp) and showed >80% identity with the sequences of the homologous genes (849 bp) in the cattle parasites. Alignment of the inferred aa sequences with those of Theileria sergenti and Theileria buffeli predicted that there is an insertion of a single residue at the N-terminus in the inferred polypeptide of the buffalo parasite. Phylogenetic analyses based on the aa sequences suggested that Theileria sp. of the Asian buffalo should be classified within the benign Theileria parasite group as a separate species from the cattle parasites. Based on this, we propose a rearrangement of the currently used classification for the benign Theileria species in cattle and Asian buffalo.  相似文献   

14.
This report describes the use of Bayesian methods to analyze polyprotein coding region sequences (n = 217) obtained from GenBank to define the genome-wide phylogeny of foot and mouth disease virus (FMDV). The results strongly supported the monophyly of five FMDV serotypes, O, A, Asia 1, C, and SAT 3, while sequences for the two remaining FMDV serotypes, SAT 1 and SAT 2 did not separate into entirely distinct clades. The phylogenomic tree revealed three sister-group relationships, serotype O + Asia 1, A + C, and SAT 1 + 3 + 2, with a new branching pattern: {[(O, Asia 1), (A, C)], (SAT 1, 2, 3)}. Within each serotype, there was no apparent periodic, geographic, or host species influence on the evolution of global FMDVs. Analysis of the polyprotein coding region of these sequences provided evidence for the influence of purifying selection on the evolution of FMDV. Using a Bayesian coalescent approach, the evolutionary rate of FMDV isolates that circulated during the years 1932-2007 was estimated to be 1.46 × 10(-3) substitutions/site/year, and the most recent common ancestor of the virus existed approximately 481 years ago. Bayesian skyline plot revealed a population expansion in the early 20(th) century that was followed by a rapid decline in population size from the late 20(th) century to the present day. These findings provide new insights into the mechanisms that impact on the evolution of this important livestock pathogen.  相似文献   

15.
With its vast territory and complex natural environment, China boasts rich cattle genetic resources. To gain the further insight into the genetic diversity and paternal origins of Chinese cattle, we analyzed the polymorphism of Y‐SNPs (UTY19 and ZFY10) and Y‐STRs (INRA189 and BM861) in 34 Chinese cattle breeds/populations, including 606 males representative of 24 cattle breeds/populations collected in this study as well as previously published data for 302 bulls. Combined genotypic data identified 14 Y‐chromosome haplotypes that represented three haplogroups. Y2‐104‐158 and Y2‐102‐158 were the most common taurine haplotypes detected mainly in northern and central China, whereas the indicine haplotype Y3‐88‐156 predominates in southern China. Haplotypes Y2‐108‐158, Y2‐110‐158, Y2‐112‐158 and Y3‐92‐156 were private to Chinese cattle. The population structure revealed by multidimensional scaling analysis differentiated Tibetan cattle from the other three groups of cattle. Analysis of molecular variance showed that the majority of the genetic variation was explained by the genetic differences among groups. Overall, our study indicates that Chinese cattle retain high paternal diversity (= 0.607 ± 0.016) and probably much of the original lineages that derived from the domestication center in the Near East without strong admixture from commercial cattle carrying Y1 haplotypes.  相似文献   

16.
Echinococcus granulosus is a parasitic helminth which affects both man and animals. During infection with larval stage of the organism secretory and membrane-bound (S/M) proteins play a meaningful role for evasion of immune system. Antigen B (AgB) is one of them. Present investigation has defined sequence diversity of AgB2 subunit of cattle and buffalo isolates of the organism. A total of 55 isolates were screened by polymerase chain reaction based single stranded conformation polymorphism (PCR-SSCP). Subsequently, six conformers could be detected. Based on predicted aminoacid sequences of 90 aminoacid residues, three clusters could be deduced. Sequence information of two buffalo isolates was homologous to AgB4 indicating gene switching phenomenon in between closely related isoforms. Numerical value of Tajima’s D test proved negative selection pressure. Using artificial neural network (ANN), B cell linear epitope and stretches of agretope were predicted. Three clusters could be defined on the basis of B cell linear epitope. Out of three clusters, two showed more than 50% binding propensity with same MHCII alleles whereas, cluster 3 exhibited binding propensity with other MHCII alleles (DRB1_1501, DRB1_1502). Relative expression of AgB2 was more in active cysts (1.636 ± 0.092) followed by degenerating (0.449 ± 0.037) and calcified (0.255 ± 0.008). This result suggested that relative expression of AgB2 declines with progression of the disease. Using recombinant AgB2 sensitivity, specificity and accuracy of the ELISA test was 96.7, 94.7 and 95.9%, respectively. No cross reactivity was found with common cestode and trematode infected cattle and buffalo because cross reactive antigen was expressed intracellularly. Finally, this was concluded that AgB2 is the suitable immunological marker for detection, diagnosis and progression of the disease.  相似文献   

17.
Mini- and microsatellite sequences show high levels of variation and therefore provide excellent tools for both the genotyping and population genetic analysis of parasites. Herein we describe the identification of a panel of 11 polymorphic microsatellites and 49 polymorphic minisatellites of the protozoan haemoparasite Theileria parva. The PCR products were run on high resolution Spreadex gels on which the alleles were identified and sized. The sequences of the mini- and microsatellites were distributed across the four chromosomes with 16 on chromosome 1, 12 on chromosome 2, 14 on chromosome 3 and 18 on chromosome 4. The primers from the 60 sequences were tested against all the Theileria species that co-infect cattle in East and Southern Africa and were found to be specific for T. parva. In order to demonstrate the utility of these markers, we characterised eight tissue culture isolates of T. parva isolated from cattle in widely separated regions of Eastern and Southern Africa (one from Zambia, one from Uganda, two from Zimbabwe, four from Kenya) and one Kenyan tissue culture isolate from Cape buffalo (Syncerus caffer). The numbers of alleles per locus range from three to eight indicating a high level of diversity between these geographically distinct isolates. We also analysed five isolates from cattle on a single farm at Kakuzi in the central highlands of Kenya and identified a range of one to four alleles per locus. Four of the Kakuzi isolates represented distinct multilocus genotypes while two exhibited identical multilocus genotypes. This indicates a high level of diversity in a single population of T. parva. Cluster analysis of multilocus genotypes from the 14 isolates (using a neighbour joining algorithm) revealed that genetic similarity between isolates was not obviously related to their geographical origin.  相似文献   

18.
Days open (DO), which is the interval from calving to conception, is an important trait related to reproductive performance in cattle. To identify quantitative trait loci for DO in Japanese Black cattle, we conducted a genome‐wide association study with 33 303 single nucleotide polymorphisms (SNPs) using 459 animals with extreme DO values selected from a larger group of 15 488 animals. We identified a SNP on bovine chromosome 2 (BTA2) that was associated with DO. After imputation using phased haplotype data inferred from 586 812 SNPs of 1041 Japanese Black cattle, six SNPs associated with DO were located in an 8.5‐kb region of high linkage disequilibrium on BTA2. These SNPs were located on the telomeric side at a distance of 177 kb from the parathyroid hormone 2 receptor (PTH2R) gene. The association was replicated in a sample of 1778 animals. In the replicated population, the frequency of the reduced‐DO allele (Q) was 0.63, and it accounted for 1.72% of the total genetic variance. The effect of a Q‐to‐q allele substitution on DO was a decrease of 3.74 days. The results suggest that the Q allele could serve as a marker in Japanese Black cattle to select animals with superior DO performance.  相似文献   

19.
We used multiple methods to examine livestock depredation by African lions (Panthera leo), spotted hyaenas (Crocuta crocuta), leopards (Panthera pardus) and black‐backed jackals (Canis mesomelas) in livestock enclosures across the Maasai steppe of Northern Tanzania. In this landscape, pastoralists keep cattle, goats, sheep and donkeys. All are vulnerable to depredation by carnivores. Various factors, such as boma characteristics, landscape attributes and attacks by multiple carnivores, were analysed to understand the best predictors of livestock loss at a boma. We found that livestock depredation was significantly correlated with the number of carnivore species that attacked the boma, the number of boma fences and proximity to protected areas, rivers and roads. Bomas with one fence experienced more loss than those with two walls of fencing. We also found that livestock depredation increased farther from protected areas (β = 0.50, SE = 0.10) and rivers (β = 0.39, SE = 0.10) and closer to roads (β = ?0.28, SE = 0.11). These results highlight the complex interaction of fine‐scale factors that influence carnivore depredation of livestock at any given boma. We recommend that mitigation address the range of factors, including the structural integrity of a boma, landscape attributes and multiple carnivore raids.  相似文献   

20.
A comparative study was conducted on protein tyrosine phosphorylation events of capacitating sperm of two ruminant species, cattle and buffalo. Ejaculated cattle and buffalo bull spermatozoa were suspended separately in sp-TALP medium at 50 × 106 mL−1 and incubated at 38.5 °C with 5% CO2 in air in the absence or presence of heparin for a period of 6 h. The extent of sperm capacitation after various periods of incubations was assessed by lysophosphatidyl choline-induced acrosome reaction followed by a triple-staining technique and capacitation-associated tyrosine-phosphorylated proteins were detected by immunoblotting technique using a monoclonal antiphosphotyrosine antibody. In the same media, over a time-period, a significant increase in capacitation percentage was observed even in control group of buffalo spermatozoa as compared to a non-significant increase in that of cattle sperm. In both cattle and buffalo spermatozoa, at 6 h, four proteins of molecular weight 49, 45, 32, and 20 kDa (designated as p49, p45, p32, and p20) were tyrosine phosphorylated. However, in buffalo, two additional proteins of 38 and 30 kDa were also tyrosine phosphorylated. In a time-course study, p20 appeared as early as at 0 h in capacitated buffalo spermatozoa as compared to 4 h in cattle. Further, in heparin-treated buffalo spermatozoa, with a time-dependent increase in tyrosine phosphorylation of some proteins, there was time-dependent dephosphorylation of some other proteins that was never seen in heparin-treated cattle sperm. Thus, the present findings revealed that though buffalo sperm takes more time than cattle for capacitation but its associated protein tyrosine phosphorylation event starts very early as compared to cattle.  相似文献   

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