Background: Haemonchosis is a major economic problem in goat production in humid, tropical and subtropical regions. The disease is caused by an abomasal nematode, Haemonchus contortus, which is highly pathogenic in sm...Background: Haemonchosis is a major economic problem in goat production in humid, tropical and subtropical regions. The disease is caused by an abomasal nematode, Haemonchus contortus, which is highly pathogenic in small ruminants. The aim of this study was to identifying single-nucleotide polymorphisms(SNP) that were associated with fecal egg counts(FEC) and could be used as markers to identify resistance to H. contortus in goats.Results: Ten novel variants in the CI TA, ATP2 A3, HSPA8, STAT5 B, ESYT1, and SERPING1 genes were associated with FEC in goats with a nominal significance level of P < 0.05. Two missense mutation in the exon region of the caprine CI TA gene resulted in replacement of arginine with cysteine at position 9473550(R9473550 C) and aspartic acid with glutamic acid at position 9473870(D9473870 E). Chinese goat breeds had significantly higher FEC than Bangladeshi goat breeds within their respective genotypes. Polymorphism information content(PIC), effective al ele number(Ne), and heterozygosity(He)were greatest for the STAT5 B197A > G SNP locus in al goat breeds. Pairwise coefficients of linkage disequilibrium(D′, r2)revealed complete LD(r2= 1) between significant SNP polymorphisms in CI TA and SERPING1 and strong LD(r2= 0.93 and0.98) between polymorphisms in HSPA8 and ATP2 A3, respectively. Correlation coefficient(r) between FEC and body weight(BW) was significantly positive(r = 0.56***, P < 0.001) but that between FEC and packed cel volume(PCV) was negatively significant(r =-0.47**, P < 0.01) in the total population of goats. On the other hand, correlation coefficient(r)between BW and PCV was not significant in total population of goats. Association analysis revealed that haplotypes within ATP2 A3, HSPA8, and SERPING1 were significantly associated with FEC. Quantitative real-time PCR revealed that the relative expression of m RNA was higher(P < 0.001) for resistant, compared to susceptible, groups of goats for al candidate genes except CI TA.Conclusions: This study identified SNP markers that can potential y be used in marker-assisted selection programs to develop goat breeds that are resistant to H. contortus.展开更多
Objective:To elucidate the pharmacological bases of oral administration of Securidaca longepedunculata(S.longepedunculata) root extract as an anthelmintic in folkloric medicine. Methods:Albino mice were infected with ...Objective:To elucidate the pharmacological bases of oral administration of Securidaca longepedunculata(S.longepedunculata) root extract as an anthelmintic in folkloric medicine. Methods:Albino mice were infected with infective third(L3) larval stage of Heligmosomoides polygyrus(H.polygyrus) by esophageal intubation.Following establishment of the adult worms in the intestine,the mice were treated with 0-2 000 mg/kg body weight(bw) of methanolic root extract of S.longepedunculata and 100 mg/kg bw of pyrantel embonate,the reference drug in vivo. Bioactivity and larvicidal effects of the extract were tested by exposing brine shrimps(Artemia salina) to 0.00-1.00 mg/mL and the L3 stage of Heligmosomoides contortus(H.contortus) and H.polygyrus to 0.00-2.50 mg/mL of the extract in vitro.Results:The percentage yield of the extract was 7.13%w/w dry matter.The brine shrimps toxicity bioassay resulted in an LC_(50) of 74.18 μ g/mL.The extract had a significant,dose-dependent larvicidal effect on the L3 stage of H.contortus and H.polygyrus with the terminal effect of 75%and 70%at the highest exposure concentrations,respectively.The extract however,did not affect the number of worm eggs per gram(epg) of fecal materials(P<0.05) and total worm burden(twb) of adult H.polygyrus in infected mice.Treatment with pyrantel embonate significant reduced both the fecal egg count and twb to 0 compared to the untreated control(P<0.05).Conclusions:These results indicate that S.longepedunculata root extract contains potent bioactive compounds and has larvicidal effect on L3 stage of H.contortus and H.polygyrus,substantiating its use as anthelmintic in alternative medicine.展开更多
基金supported by the National Nature Science Foundation of China(grant no.31402040)a CRP project(grant no.16087 for China and grant no.16073 for Bangladesh)from the International Atomic Energy Agency
文摘Background: Haemonchosis is a major economic problem in goat production in humid, tropical and subtropical regions. The disease is caused by an abomasal nematode, Haemonchus contortus, which is highly pathogenic in small ruminants. The aim of this study was to identifying single-nucleotide polymorphisms(SNP) that were associated with fecal egg counts(FEC) and could be used as markers to identify resistance to H. contortus in goats.Results: Ten novel variants in the CI TA, ATP2 A3, HSPA8, STAT5 B, ESYT1, and SERPING1 genes were associated with FEC in goats with a nominal significance level of P < 0.05. Two missense mutation in the exon region of the caprine CI TA gene resulted in replacement of arginine with cysteine at position 9473550(R9473550 C) and aspartic acid with glutamic acid at position 9473870(D9473870 E). Chinese goat breeds had significantly higher FEC than Bangladeshi goat breeds within their respective genotypes. Polymorphism information content(PIC), effective al ele number(Ne), and heterozygosity(He)were greatest for the STAT5 B197A > G SNP locus in al goat breeds. Pairwise coefficients of linkage disequilibrium(D′, r2)revealed complete LD(r2= 1) between significant SNP polymorphisms in CI TA and SERPING1 and strong LD(r2= 0.93 and0.98) between polymorphisms in HSPA8 and ATP2 A3, respectively. Correlation coefficient(r) between FEC and body weight(BW) was significantly positive(r = 0.56***, P < 0.001) but that between FEC and packed cel volume(PCV) was negatively significant(r =-0.47**, P < 0.01) in the total population of goats. On the other hand, correlation coefficient(r)between BW and PCV was not significant in total population of goats. Association analysis revealed that haplotypes within ATP2 A3, HSPA8, and SERPING1 were significantly associated with FEC. Quantitative real-time PCR revealed that the relative expression of m RNA was higher(P < 0.001) for resistant, compared to susceptible, groups of goats for al candidate genes except CI TA.Conclusions: This study identified SNP markers that can potential y be used in marker-assisted selection programs to develop goat breeds that are resistant to H. contortus.
文摘Objective:To elucidate the pharmacological bases of oral administration of Securidaca longepedunculata(S.longepedunculata) root extract as an anthelmintic in folkloric medicine. Methods:Albino mice were infected with infective third(L3) larval stage of Heligmosomoides polygyrus(H.polygyrus) by esophageal intubation.Following establishment of the adult worms in the intestine,the mice were treated with 0-2 000 mg/kg body weight(bw) of methanolic root extract of S.longepedunculata and 100 mg/kg bw of pyrantel embonate,the reference drug in vivo. Bioactivity and larvicidal effects of the extract were tested by exposing brine shrimps(Artemia salina) to 0.00-1.00 mg/mL and the L3 stage of Heligmosomoides contortus(H.contortus) and H.polygyrus to 0.00-2.50 mg/mL of the extract in vitro.Results:The percentage yield of the extract was 7.13%w/w dry matter.The brine shrimps toxicity bioassay resulted in an LC_(50) of 74.18 μ g/mL.The extract had a significant,dose-dependent larvicidal effect on the L3 stage of H.contortus and H.polygyrus with the terminal effect of 75%and 70%at the highest exposure concentrations,respectively.The extract however,did not affect the number of worm eggs per gram(epg) of fecal materials(P<0.05) and total worm burden(twb) of adult H.polygyrus in infected mice.Treatment with pyrantel embonate significant reduced both the fecal egg count and twb to 0 compared to the untreated control(P<0.05).Conclusions:These results indicate that S.longepedunculata root extract contains potent bioactive compounds and has larvicidal effect on L3 stage of H.contortus and H.polygyrus,substantiating its use as anthelmintic in alternative medicine.
