The epidemic situation of A H1N1 flu arose in North America in April 2009,which rapidly expanded to three continents of Europe,Asia and Africa,with the risk ranking up to 5.Until May 13th,the flu virus of A H1N1 had s...The epidemic situation of A H1N1 flu arose in North America in April 2009,which rapidly expanded to three continents of Europe,Asia and Africa,with the risk ranking up to 5.Until May 13th,the flu virus of A H1N1 had spread into 33 countries and regions,with a laboratory confirmed case number of 5728,including 61 deaths.Based on IRV and EpiFluDB database,425 parts of A H1N1 flu virus sequence were achieved,followed by sequenced comparison and evolution analysis.The results showed that the current predominant A H1N1 flu virus was a kind of triple reassortment A flu virus:(i) HA,NA,MP,NP and NS originated from swine influenza virus;PB2 and PA originated from bird influenza virus;PB1 originated from human influenza virus.(ii) The origin of swine influenza virus could be subdivided as follows:HA,NP and NS originated from classic swine influenza virus of H1N1 subtype;NA and MP originated from bird origin swine influenza virus of H1N1 subtype.(iii) A H1N1 flu virus experienced no significant mutation during the epidemic spread,accompanied with no reassortment of the virus genome.In the paper,the region of the representative strains for sequence analysis(A/California/04/2009(H1N1) and A/Mexico/4486/2009(H1N1)) included USA and Mexico and was relatively wide,which suggested that the analysis results were convincing.展开更多
Base substitution is one of the raw fuels that produce genetic variation and drive evolu-tion. Recent studies have shown that the genome components affect mutation patterns to some extent. In order to infer the correl...Base substitution is one of the raw fuels that produce genetic variation and drive evolu-tion. Recent studies have shown that the genome components affect mutation patterns to some extent. In order to infer the correlation between the Transition/Transversion ratio (Ts/Tv) and the number of immediately adjacent A&T nucleotides, we investigated 3611007 Oryza sativa SNPs (including 45462 coding SNPs, and 242811 intronic SNPs) and 32019 Arabidopsis SNPs. The results show that Ts/Tv is negatively correlated with the number of immediately adjacent A&T in O. sativa and Arabidopsis. We further calculated AT2 (the number of SNPs whose immediately adjacent nucleotides are either A or T) and AT0 (the number of SNPs whose immediately adjacent nucleotides are either C or G) for all 6 types of SNPs. C/G SNP of O. sativa and Arabidopsis has the highest AT2/AT0, which denotes C/G SNP may be influenced by the adjacent A&T nucleotides mostly. For SNPs in O. sativa, the neighboring effect of A&T nucleotides is limited to 2 nucleotides on both sides; for SNPs in Arabidop-sis, the effect extends no more than 4 nucleotides on both sides.展开更多
Mammalian testis development is a complex and highly sophisticated process. To study the dynamic change of normal testis development at the transcriptional level, we investigated mouse testes at three postnatal ages: ...Mammalian testis development is a complex and highly sophisticated process. To study the dynamic change of normal testis development at the transcriptional level, we investigated mouse testes at three postnatal ages: 6 days postnatal, 4 weeks old, and 10 weeks old, representing infant (PN1), juvenile (PN2), and adult (PN3) stages, respectively. Using ultra high-throughput RNA sequencing (RNA-seq) technology, we obtained 211 million reads with a length of 35 bp. We identified 18837 genes that were expressed in mouse testes, and found that genes expressed at the highest level were involved in spermatogenesis. The gene expression pattern in PN1 was distinct from that in PN2 and PN3, which indicates that spermatogenesis has commenced in PN2. We analyzed a large number of genes related to spermatogenesis and somatic development of the testis, which play important roles at different developmental stages. We also found that the MAPK, Hedgehog, and Wnt signaling pathways were significantly involved at different developmental stages. These findings further our understanding of the molecular mechanisms that regulate testis development. Our study also demonstrates significant advantages of RNA-seq technology for studying transcriptome during development.展开更多
Spermatogenesis is a complicated and poorly understood process that relies on the precise regulation of the self-renewal and differentiation of spermatogonia. In many organisms, micro RNAs(mi RNAs) are involved in mul...Spermatogenesis is a complicated and poorly understood process that relies on the precise regulation of the self-renewal and differentiation of spermatogonia. In many organisms, micro RNAs(mi RNAs) are involved in multiple developmental processes as critical regulators of transcriptional and post-transcriptional gene silencing. This study investigated the expression pattern of mi RNAs in type B spermatogonia cells(BSc) and primary spermatocytes(PSc) of mice, using a high-throughput small RNA sequencing system. The results revealed that the expression levels of Let-7 family mi RNAs were remarkably high in both cell types. Furthermore, the expression levels of mi R-21, mi R-140-3p, mi R-103, mi R-30 a, mi R-101 b and mi R-99 b were decreased during the transformation from BSc to PSc. These mi RNAs target vital genes that participate in apoptosis, cell proliferation and differentiation, junction assembly and cell cycle regulation. These results highlight the indispensable role of mi RNAs in spermatogenesis.展开更多
An organ unique to mammals,the mammary gland develops 90%of its mass after birth and experiences the pregnancy-lactation-involution cycle(PL cycle)during reproduction.To understand mammogenesis at the transcriptomic l...An organ unique to mammals,the mammary gland develops 90%of its mass after birth and experiences the pregnancy-lactation-involution cycle(PL cycle)during reproduction.To understand mammogenesis at the transcriptomic level and using a ribo-minus RNA-seq protocol,we acquired greater than 50 million reads each for the mouse mammary gland during pregnancy(day 12 of pregnancy),lactation(day 14 of lactation),and involution(day 7 of involution).The pregnancy-,lactation-and involution-related sequencing reads were assembled into 17344,10160,and 13739 protein-coding transcripts and1803,828,and 1288 non-coding RNAs(ncRNAs),respectively.Differentially expressed genes(DEGs)were defined in the three samples,which comprised 4843 DEGs(749 up-regulated and 4094 down-regulated)from pregnancy to lactation and4926 DEGs(4706 up-regulated and 220 down-regulated)from lactation to involution.Besides the obvious and substantive upand down-regulation of the DEGs,we observe that lysosomal enzymes were highly expressed and that their expression coincided with milk secretion.Further analysis of transcription factors such as Trps1,Gtf2i,Tcf7l2,Nupr1,Vdr,Rb1,and Aebp1,and ncRNAs such as mir-125b,Let7,mir-146a,and mir-15 has enabled us to identify key regulators in mammary gland development and the PL cycle.展开更多
基金Supported by the National Key Basic Research and Development of China(Grant Nos.2007FY210700,2005CB523007)Knowledge Innovation Project of the Chinese Academy of Sciences(Grant No.KSCX2-YW-N-065)+1 种基金e-Science Project of the Chinese Academy of Sciences(Grant No.IN-FO-115-D02)Sixth Framework Program in European(Grant Nos.SP5B-CT-2006-044161,SP5B-CT-2006-044405)
文摘The epidemic situation of A H1N1 flu arose in North America in April 2009,which rapidly expanded to three continents of Europe,Asia and Africa,with the risk ranking up to 5.Until May 13th,the flu virus of A H1N1 had spread into 33 countries and regions,with a laboratory confirmed case number of 5728,including 61 deaths.Based on IRV and EpiFluDB database,425 parts of A H1N1 flu virus sequence were achieved,followed by sequenced comparison and evolution analysis.The results showed that the current predominant A H1N1 flu virus was a kind of triple reassortment A flu virus:(i) HA,NA,MP,NP and NS originated from swine influenza virus;PB2 and PA originated from bird influenza virus;PB1 originated from human influenza virus.(ii) The origin of swine influenza virus could be subdivided as follows:HA,NP and NS originated from classic swine influenza virus of H1N1 subtype;NA and MP originated from bird origin swine influenza virus of H1N1 subtype.(iii) A H1N1 flu virus experienced no significant mutation during the epidemic spread,accompanied with no reassortment of the virus genome.In the paper,the region of the representative strains for sequence analysis(A/California/04/2009(H1N1) and A/Mexico/4486/2009(H1N1)) included USA and Mexico and was relatively wide,which suggested that the analysis results were convincing.
基金supported partly by the National 863 Project(Grant No.2003AA231050)National Natural Science Foundation of China(Grant No.10371126)Mega-projects of Science Research for the 10th Five-year Plan(Grant No.2002BA711A09).
文摘Base substitution is one of the raw fuels that produce genetic variation and drive evolu-tion. Recent studies have shown that the genome components affect mutation patterns to some extent. In order to infer the correlation between the Transition/Transversion ratio (Ts/Tv) and the number of immediately adjacent A&T nucleotides, we investigated 3611007 Oryza sativa SNPs (including 45462 coding SNPs, and 242811 intronic SNPs) and 32019 Arabidopsis SNPs. The results show that Ts/Tv is negatively correlated with the number of immediately adjacent A&T in O. sativa and Arabidopsis. We further calculated AT2 (the number of SNPs whose immediately adjacent nucleotides are either A or T) and AT0 (the number of SNPs whose immediately adjacent nucleotides are either C or G) for all 6 types of SNPs. C/G SNP of O. sativa and Arabidopsis has the highest AT2/AT0, which denotes C/G SNP may be influenced by the adjacent A&T nucleotides mostly. For SNPs in O. sativa, the neighboring effect of A&T nucleotides is limited to 2 nucleotides on both sides; for SNPs in Arabidop-sis, the effect extends no more than 4 nucleotides on both sides.
基金supported by the National Basic Research Program of China(2011CB944100,2011CB944101)the National Natural Science Foundation of China (90919024)+1 种基金the Special Foundation Work Program of Ministry of Science and Technology (2009FY120100)the National High Technology Research and Development Program of Ministry of Science and Technology of China (2012AA020409)
文摘Mammalian testis development is a complex and highly sophisticated process. To study the dynamic change of normal testis development at the transcriptional level, we investigated mouse testes at three postnatal ages: 6 days postnatal, 4 weeks old, and 10 weeks old, representing infant (PN1), juvenile (PN2), and adult (PN3) stages, respectively. Using ultra high-throughput RNA sequencing (RNA-seq) technology, we obtained 211 million reads with a length of 35 bp. We identified 18837 genes that were expressed in mouse testes, and found that genes expressed at the highest level were involved in spermatogenesis. The gene expression pattern in PN1 was distinct from that in PN2 and PN3, which indicates that spermatogenesis has commenced in PN2. We analyzed a large number of genes related to spermatogenesis and somatic development of the testis, which play important roles at different developmental stages. We also found that the MAPK, Hedgehog, and Wnt signaling pathways were significantly involved at different developmental stages. These findings further our understanding of the molecular mechanisms that regulate testis development. Our study also demonstrates significant advantages of RNA-seq technology for studying transcriptome during development.
基金supported by the National Natural Science Foundation of China(81170616,81072093,30671092,81302323,31100915)the Natural Science Foundation of Hebei Province(C2014209140,C2009001260,C2012401039,H2013209194,C2013209024)the Scientific and Technical Supporting Programs of Hebei Province(10276109D)
文摘Spermatogenesis is a complicated and poorly understood process that relies on the precise regulation of the self-renewal and differentiation of spermatogonia. In many organisms, micro RNAs(mi RNAs) are involved in multiple developmental processes as critical regulators of transcriptional and post-transcriptional gene silencing. This study investigated the expression pattern of mi RNAs in type B spermatogonia cells(BSc) and primary spermatocytes(PSc) of mice, using a high-throughput small RNA sequencing system. The results revealed that the expression levels of Let-7 family mi RNAs were remarkably high in both cell types. Furthermore, the expression levels of mi R-21, mi R-140-3p, mi R-103, mi R-30 a, mi R-101 b and mi R-99 b were decreased during the transformation from BSc to PSc. These mi RNAs target vital genes that participate in apoptosis, cell proliferation and differentiation, junction assembly and cell cycle regulation. These results highlight the indispensable role of mi RNAs in spermatogenesis.
基金supported by grant from Ministry of Science and Technology of China (2011CB944100,2011CB944101)
文摘An organ unique to mammals,the mammary gland develops 90%of its mass after birth and experiences the pregnancy-lactation-involution cycle(PL cycle)during reproduction.To understand mammogenesis at the transcriptomic level and using a ribo-minus RNA-seq protocol,we acquired greater than 50 million reads each for the mouse mammary gland during pregnancy(day 12 of pregnancy),lactation(day 14 of lactation),and involution(day 7 of involution).The pregnancy-,lactation-and involution-related sequencing reads were assembled into 17344,10160,and 13739 protein-coding transcripts and1803,828,and 1288 non-coding RNAs(ncRNAs),respectively.Differentially expressed genes(DEGs)were defined in the three samples,which comprised 4843 DEGs(749 up-regulated and 4094 down-regulated)from pregnancy to lactation and4926 DEGs(4706 up-regulated and 220 down-regulated)from lactation to involution.Besides the obvious and substantive upand down-regulation of the DEGs,we observe that lysosomal enzymes were highly expressed and that their expression coincided with milk secretion.Further analysis of transcription factors such as Trps1,Gtf2i,Tcf7l2,Nupr1,Vdr,Rb1,and Aebp1,and ncRNAs such as mir-125b,Let7,mir-146a,and mir-15 has enabled us to identify key regulators in mammary gland development and the PL cycle.