[ Objective] To find the dominant rabies virus strains that are epidemic in Guangdong Province and thus to better prevent and control rabies. [ Method] Canine brains and salivary glands collected from several regions ...[ Objective] To find the dominant rabies virus strains that are epidemic in Guangdong Province and thus to better prevent and control rabies. [ Method] Canine brains and salivary glands collected from several regions of Guangdong Province were detected by direct imrnunofluorescence assay and nested RT-PCR. The isolates were further identified by intracranial inoculation in suckling mice. The N gene was amplified by RTPCR and the sequences were aligned with those of prevalent strains in Guangxi region and vaccine strains. [ Result] Two strains were isolated from specimens collected from Guangdong Province. Their N gene sequences had a high similarity of 97.9% -99.4% to those of Guangxi strains and also had a similarity of 87.7% -88.1% to those of vaccine strains of rabies virus. [ Conclusion] Apparently healthy dogs may carry rabies virus, and the prevalence of rabies virus shows obvious regional differences.展开更多
Viral diseases are among the most critical damaging factors that impose a global threat to the cucurbit industry.China is the world’s leading country for the production and consumption of cucurbits.Guangdong,a provin...Viral diseases are among the most critical damaging factors that impose a global threat to the cucurbit industry.China is the world’s leading country for the production and consumption of cucurbits.Guangdong,a province in southern China dominated by the tropical and subtropical climate,favors the survival of different plant viruses and their vectors.Five main cucurbit crops showing various disease symptoms were surveyed and collected to identify viruses infecting cucurbits in Guangdong during 2018–2020.In the field,the incidence ranged from 5-30%,or even 60-100% in the case of severely infected cucurbits.A total of 357 symptomatic samples were collected and subsequently screened for cucurbit viruses by small RNA deep sequencing and assembly(sRSA).Seventeen virus species belonging to 10 genera were identified in the five main cucurbit crops.The most common viruses were papaya ringspot virus(PRSV;Potyvirus),zucchini tigre mosaic virus(ZTMV;Potyvirus),zucchini yellow mosaic virus(ZYMV;Potyvirus),and watermelon silver mottle virus(WSMoV;Orthotospovirus),with infection rates of 24.4,19.0,17.1,and 14.3%,respectively.Notably,the most prevalent viruses were melon yellow spot orthotospovirus(MYSV)in cucumber,PRSV in squash,cucumber green mottle mosaic virus(CGMMV;Tobamovirus)in bottle gourd,WSMoV in white gourd,and ZYMV in luffa.Mixed infections were prevalent,and the types of mixed infections varied substantially in different cucurbit crops.Moreover,the full-length nucleotide sequences of watermelon green mottle mosaic virus(WGMMV),CGMMV,and watermelon virus A(WVA;Wamavirus)identified in bottle gourd were cloned and analyzed.This study is the first reporting WGMMV infecting bottle gourd in China mainland.In summary,the results demonstrate that in Guangdong,the most prevalent viruses belong to potyviruses,orthotospoviruses,and tobamoviruses groups.The findings will facilitate agricultural researchers and farmers to plan and implement effective disease control strategies aiming at timely detection and management of cucurbit-infecting viral pathogens.展开更多
Simple sequence repeats(SSRs)exist in both eukaryotic and prokaryotic genomes and are the most popular genetic markers,but the SSRs of mosquito genomes are still not well understood.In this study,we identified and ana...Simple sequence repeats(SSRs)exist in both eukaryotic and prokaryotic genomes and are the most popular genetic markers,but the SSRs of mosquito genomes are still not well understood.In this study,we identified and analyzed the SSRs in 23 mosquito species using Drosophila melanogaster as reference at the whole-genome level.The results show that SSR numbers(33076-560175/genome)and genome sizes(574.57-1342.21 Mb)are significantly positively correlated(R~=0.8992,P<0.01),but the correlation in individual species varies in these mosquito species.In six types of SSR,mono-to trinucleotide SSRs are dominant with cumulative percentages of 95.14%-99.00%and densities of 195.65/Mb-787.51/Mb,whereas tetra-to hexanucleotide SSRs are rare with 1.12%-4.22%and 3.76/Mb-40.23/Mb.The(A/T)n,(AC/GT)n and(AGC/GCT)n are the most frequent motifs in mononucleotide,dinucleotide and trinucleotide SSRs,respectively,and the motif frequencies of tetra-to hexanucleotide SSRs appear to be species-specific.The 10-20 bp length of SSRs are dominant with the number of 11()561±93482 and the frequency of 87.25%±5.73%on average,and the number and frequency decline with the increase oflength.Most SSRs(83.34%±7.72%)are located in intergenic regions,followed by intron regions(11.59%±5.59%),exon regions(3.74%±1.95%),and untranslated regions(1.32%±1.39%).The mono-,di-and trinucleotide SSRs are the main SSRs in both gene regions(98.55%±0.85%)and exon regions(99.27%±0.52%).An average of 42.52%of total genes contains SSRs,and the preference for SSR occurrenee in different gene subcategories are species-specific.The study provides useful insights into the SSR diversity,characteristics and distribution in 23 mosquito species of genomes.展开更多
The demersal fish populations constitute a valuable commercial resource in the Beibu Gulf,northern South China.However,our understanding of the ontogenetic dietary shifts of fish,particularly Lagocephalus spadiceus,wh...The demersal fish populations constitute a valuable commercial resource in the Beibu Gulf,northern South China.However,our understanding of the ontogenetic dietary shifts of fish,particularly Lagocephalus spadiceus,which is the most widely distributed fish in the northern South China Sea,is lacking.Therefore,we conducted a study using high-throughput sequencing and stable isotope analyses to examine the diet of L.spadiceus.The individuals were collected during 2 bottom trawl surveys in April and August 2022.The length distribution showed that small L.spadiceus was more abundant in shallow water,whereas large fish were generally found in offshore water.High-throughput sequencing indicated that L.spadiceus mainly fed on crustaceans and fish.Ontogenetic changes in diet composition and stable isotope values were also observed.As L.spadiceus grew,they started preying on larger individuals,specifically fish.The^(15)N enrichment in large fish supported to small fish supports these findings.The trophic niche indicated a segregation between individuals in shallow waters(mostly small fish)and offshore waters(mostly large fish),which helps in reducing the competition within the species.The L.spadiceus occupied the role of mid-predator(trophic level~3.66)and increased with body length and water depth.Consequently,both high-throughput sequencing and stable isotope analyses provided evidence of intraspecific dietary variation and trophic niche partitioning of L.spadiceus in the Beibu Gulf,South China Sea.展开更多
为鉴定我国黑龙江省分离的狍子源鞭虫的种类及确定其在鞭虫中的分类地位,本研究首先对鞭虫进行形态学特征观察,并利用PCR方法扩增该鞭虫r DNA ITS序列,经测序分析结果表明,r DNA ITS序列全长为1 371 bp,其中ITS1、5.8S及ITS2大小分别为8...为鉴定我国黑龙江省分离的狍子源鞭虫的种类及确定其在鞭虫中的分类地位,本研究首先对鞭虫进行形态学特征观察,并利用PCR方法扩增该鞭虫r DNA ITS序列,经测序分析结果表明,r DNA ITS序列全长为1 371 bp,其中ITS1、5.8S及ITS2大小分别为800 bp、163 bp及408 bp,与之前报道的狍子源鞭虫同源性达99.8%。将其与NCBI数据库中相应鞭虫ITS序列进行比对分析,并将r DNA ITS序列作为基因标记构建鞭虫属系统发生树,结果显示本研究所分离的狍子源鞭虫与其他不同宿主的无色鞭虫均处于同一个分支,因此可鉴定本研究分离的我国狍子源鞭虫为无色鞭虫。本研究为国内首次对狍子源鞭虫进行分子鉴定及系统进化分析,为草食动物的鞭虫病分子鉴别诊断和鞭虫系统进化分析研究提供依据。展开更多
基金supported by the grants of the Surveillance,Prevention and Control Technology Research and Demonstration Projects for Animal Rabies ( Science and Education Department of the Ministry of Agriculture,200803014) the Public Laboratory Open Fund ( Host Ecology as well as Construction of Immune Surveillance and Control System,GSKJ090103)
文摘[ Objective] To find the dominant rabies virus strains that are epidemic in Guangdong Province and thus to better prevent and control rabies. [ Method] Canine brains and salivary glands collected from several regions of Guangdong Province were detected by direct imrnunofluorescence assay and nested RT-PCR. The isolates were further identified by intracranial inoculation in suckling mice. The N gene was amplified by RTPCR and the sequences were aligned with those of prevalent strains in Guangxi region and vaccine strains. [ Result] Two strains were isolated from specimens collected from Guangdong Province. Their N gene sequences had a high similarity of 97.9% -99.4% to those of Guangxi strains and also had a similarity of 87.7% -88.1% to those of vaccine strains of rabies virus. [ Conclusion] Apparently healthy dogs may carry rabies virus, and the prevalence of rabies virus shows obvious regional differences.
基金supported by the grants from the National Natural Science Foundation of China(31801712)the Key Research and Development Program of Guangdong Province,China(2018B020202006)+1 种基金the Agricultural Competitive Industry Discipline Team Building Project of Guangdong Academy of Agricultural Sciences(202103TD and 202105TD)the Development Program for Guangdong Province Modern Agricultural Science and Technology Innovation Alliance(2020KJ113)。
文摘Viral diseases are among the most critical damaging factors that impose a global threat to the cucurbit industry.China is the world’s leading country for the production and consumption of cucurbits.Guangdong,a province in southern China dominated by the tropical and subtropical climate,favors the survival of different plant viruses and their vectors.Five main cucurbit crops showing various disease symptoms were surveyed and collected to identify viruses infecting cucurbits in Guangdong during 2018–2020.In the field,the incidence ranged from 5-30%,or even 60-100% in the case of severely infected cucurbits.A total of 357 symptomatic samples were collected and subsequently screened for cucurbit viruses by small RNA deep sequencing and assembly(sRSA).Seventeen virus species belonging to 10 genera were identified in the five main cucurbit crops.The most common viruses were papaya ringspot virus(PRSV;Potyvirus),zucchini tigre mosaic virus(ZTMV;Potyvirus),zucchini yellow mosaic virus(ZYMV;Potyvirus),and watermelon silver mottle virus(WSMoV;Orthotospovirus),with infection rates of 24.4,19.0,17.1,and 14.3%,respectively.Notably,the most prevalent viruses were melon yellow spot orthotospovirus(MYSV)in cucumber,PRSV in squash,cucumber green mottle mosaic virus(CGMMV;Tobamovirus)in bottle gourd,WSMoV in white gourd,and ZYMV in luffa.Mixed infections were prevalent,and the types of mixed infections varied substantially in different cucurbit crops.Moreover,the full-length nucleotide sequences of watermelon green mottle mosaic virus(WGMMV),CGMMV,and watermelon virus A(WVA;Wamavirus)identified in bottle gourd were cloned and analyzed.This study is the first reporting WGMMV infecting bottle gourd in China mainland.In summary,the results demonstrate that in Guangdong,the most prevalent viruses belong to potyviruses,orthotospoviruses,and tobamoviruses groups.The findings will facilitate agricultural researchers and farmers to plan and implement effective disease control strategies aiming at timely detection and management of cucurbit-infecting viral pathogens.
基金the National Natural Science Foundation of China(31672363,31372265)the Par-Eu Scholars Program(20136666)+2 种基金the Coordinated Research Project of the International Atomic En?ergy Agency(18268)the National Key Program of Science and Tech no logy Foundation Work of China(2015FY210300)and the Science and Technology Research Project of Chongqing Municipal Education Commission(KJ 1600304).
文摘Simple sequence repeats(SSRs)exist in both eukaryotic and prokaryotic genomes and are the most popular genetic markers,but the SSRs of mosquito genomes are still not well understood.In this study,we identified and analyzed the SSRs in 23 mosquito species using Drosophila melanogaster as reference at the whole-genome level.The results show that SSR numbers(33076-560175/genome)and genome sizes(574.57-1342.21 Mb)are significantly positively correlated(R~=0.8992,P<0.01),but the correlation in individual species varies in these mosquito species.In six types of SSR,mono-to trinucleotide SSRs are dominant with cumulative percentages of 95.14%-99.00%and densities of 195.65/Mb-787.51/Mb,whereas tetra-to hexanucleotide SSRs are rare with 1.12%-4.22%and 3.76/Mb-40.23/Mb.The(A/T)n,(AC/GT)n and(AGC/GCT)n are the most frequent motifs in mononucleotide,dinucleotide and trinucleotide SSRs,respectively,and the motif frequencies of tetra-to hexanucleotide SSRs appear to be species-specific.The 10-20 bp length of SSRs are dominant with the number of 11()561±93482 and the frequency of 87.25%±5.73%on average,and the number and frequency decline with the increase oflength.Most SSRs(83.34%±7.72%)are located in intergenic regions,followed by intron regions(11.59%±5.59%),exon regions(3.74%±1.95%),and untranslated regions(1.32%±1.39%).The mono-,di-and trinucleotide SSRs are the main SSRs in both gene regions(98.55%±0.85%)and exon regions(99.27%±0.52%).An average of 42.52%of total genes contains SSRs,and the preference for SSR occurrenee in different gene subcategories are species-specific.The study provides useful insights into the SSR diversity,characteristics and distribution in 23 mosquito species of genomes.
基金supported by the Key Research and Development Program of Guangxi(Guike AB22035050)the National Natural Science Foundation of China(U20A2087)the Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation,Beibu Gulf University(2022KA01)
文摘The demersal fish populations constitute a valuable commercial resource in the Beibu Gulf,northern South China.However,our understanding of the ontogenetic dietary shifts of fish,particularly Lagocephalus spadiceus,which is the most widely distributed fish in the northern South China Sea,is lacking.Therefore,we conducted a study using high-throughput sequencing and stable isotope analyses to examine the diet of L.spadiceus.The individuals were collected during 2 bottom trawl surveys in April and August 2022.The length distribution showed that small L.spadiceus was more abundant in shallow water,whereas large fish were generally found in offshore water.High-throughput sequencing indicated that L.spadiceus mainly fed on crustaceans and fish.Ontogenetic changes in diet composition and stable isotope values were also observed.As L.spadiceus grew,they started preying on larger individuals,specifically fish.The^(15)N enrichment in large fish supported to small fish supports these findings.The trophic niche indicated a segregation between individuals in shallow waters(mostly small fish)and offshore waters(mostly large fish),which helps in reducing the competition within the species.The L.spadiceus occupied the role of mid-predator(trophic level~3.66)and increased with body length and water depth.Consequently,both high-throughput sequencing and stable isotope analyses provided evidence of intraspecific dietary variation and trophic niche partitioning of L.spadiceus in the Beibu Gulf,South China Sea.
文摘为鉴定我国黑龙江省分离的狍子源鞭虫的种类及确定其在鞭虫中的分类地位,本研究首先对鞭虫进行形态学特征观察,并利用PCR方法扩增该鞭虫r DNA ITS序列,经测序分析结果表明,r DNA ITS序列全长为1 371 bp,其中ITS1、5.8S及ITS2大小分别为800 bp、163 bp及408 bp,与之前报道的狍子源鞭虫同源性达99.8%。将其与NCBI数据库中相应鞭虫ITS序列进行比对分析,并将r DNA ITS序列作为基因标记构建鞭虫属系统发生树,结果显示本研究所分离的狍子源鞭虫与其他不同宿主的无色鞭虫均处于同一个分支,因此可鉴定本研究分离的我国狍子源鞭虫为无色鞭虫。本研究为国内首次对狍子源鞭虫进行分子鉴定及系统进化分析,为草食动物的鞭虫病分子鉴别诊断和鞭虫系统进化分析研究提供依据。
