Project description:The objective of our study was the generation of high-throughput global gene expression profiles of somatic cells and mature reproductive cells of V. carteri separately from each other.
Project description:We identified 174 miRNAs expressed in Volvox carteri. Some of Volvox miRNAs are highly enriched in gonidia or somatic cells. Subsequently, we predicted the targets of Volvox miRNAs and found many of target genes were regulated through mRNA degradation. Conservation analysis suggests the common origin of miRNA between Volvox and Chlamydomonas and high frequency of birth and death of Volvox miRNAs.
Project description:The green alga Volvox carteri is a model organism for the development of multicellularity. It has a spherical shape with a complete division of labor between around 2000 somatic cells and 16 reproductive cells. When comparing Volvox with its unicellular relative Chlamydomonas rheinhardtii, one striking observation is the similarity in the protein coding genes [1]. Additionally, Baulcombe and colleagues showed that Chlamydomonas contains functional RNAi and miRNA machineries [2]. We deep sequenced small RNAs of the female Volvox strain HK10 in different life stages (asexual reproduction to sexual reproduction), each time dividing the samples into somatic cells and reproductive cells. This allowed for the observation not only of differences in individual life stages, but also for monitoring sRNA content in the two cell types. We show that Volvox expresses miRNAs and that they are 2â??-O-methylated at the 3â?? end. The expression profiles of several miRNAs were validated by Northern blotting showing a differential expression both between cell types and between life stages. Intriguingly, most miRNAs do not seem to be conserved between Volvox and Chlamydomonas, raising the interesting question if this changed miRNome leads to differently targeted mRNAs thus resulting in cell differentiation. Since only little is known about the transcriptome of Volvox, we performed RNASeq in order to analyze potential miRNA targets. In conclusion, most miRNA in Volvox are not conserved in Chlamydomonas although the two species are evolutionary close together. This suggests that dramatic changes in the miRNA expression might be one of the driving forces for the development of multicellularity. 1. Prochnik, S.E., et al., Genomic analysis of organismal complexity in the multicellular green alga Volvox carteri. Science, 2010. 329(5988): p. 223-6. 2. Molnar, A., et al., miRNAs control gene expression in the single-cell alga Chlamydomonas reinhardtii. Nature, 2007. 447(7148): p. 1126-9. Examination of small RNAs of Volvox carteri during different stages of its life cycle
Project description:The green alga Volvox carteri is a model organism for the development of multicellularity. It has a spherical shape with a complete division of labor between around 2000 somatic cells and 16 reproductive cells. When comparing Volvox with its unicellular relative Chlamydomonas rheinhardtii, one striking observation is the similarity in the protein coding genes [1]. Additionally, Baulcombe and colleagues showed that Chlamydomonas contains functional RNAi and miRNA machineries [2]. We deep sequenced small RNAs of the female Volvox strain HK10 in different life stages (asexual reproduction to sexual reproduction), each time dividing the samples into somatic cells and reproductive cells. This allowed for the observation not only of differences in individual life stages, but also for monitoring sRNA content in the two cell types. We show that Volvox expresses miRNAs and that they are 2’-O-methylated at the 3’ end. The expression profiles of several miRNAs were validated by Northern blotting showing a differential expression both between cell types and between life stages. Intriguingly, most miRNAs do not seem to be conserved between Volvox and Chlamydomonas, raising the interesting question if this changed miRNome leads to differently targeted mRNAs thus resulting in cell differentiation. Since only little is known about the transcriptome of Volvox, we performed RNASeq in order to analyze potential miRNA targets. In conclusion, most miRNA in Volvox are not conserved in Chlamydomonas although the two species are evolutionary close together. This suggests that dramatic changes in the miRNA expression might be one of the driving forces for the development of multicellularity. 1. Prochnik, S.E., et al., Genomic analysis of organismal complexity in the multicellular green alga Volvox carteri. Science, 2010. 329(5988): p. 223-6. 2. Molnar, A., et al., miRNAs control gene expression in the single-cell alga Chlamydomonas reinhardtii. Nature, 2007. 447(7148): p. 1126-9.
Project description:The green alga Volvox carteri is a model organism for the development of multicellularity. It has a spherical shape with a complete division of labor between around 2000 somatic cells and 16 reproductive cells. When comparing Volvox with its unicellular relative Chlamydomonas rheinhardtii, one striking observation is the similarity in the protein coding genes [1]. Additionally, Baulcombe and colleagues showed that Chlamydomonas contains functional RNAi and miRNA machineries [2]. We deep sequenced small RNAs associated with one Argonaute protein of the female Volvox strain Vol6 during its vegetative growth phase. Using these data, we established a miRNA identification pipeline that takes into account plant miRNA feature in general and also uses parameters employed in finding miRNAs in Chlamydomonas. Other small RNAs that are functionally incorporated into Ago are characterized. 1. Prochnik, S.E., et al., Genomic analysis of organismal complexity in the multicellular green alga Volvox carteri. Science, 2010. 329(5988): p. 223-6. 2. Molnar, A., et al., miRNAs control gene expression in the single-cell alga Chlamydomonas reinhardtii. Nature, 2007. 447(7148): p. 1126-9. Examination of small RNAs bound to an Argonaute protein of Volvox carteri
Project description:We identified 174 miRNAs expressed in Volvox carteri. Some of Volvox miRNAs are highly enriched in gonidia or somatic cells. Subsequently, we predicted the targets of Volvox miRNAs and found many of target genes were regulated through mRNA degradation. Conservation analysis suggests the common origin of miRNA between Volvox and Chlamydomonas and high frequency of birth and death of Volvox miRNAs. Identification of miRNAs in multicellular green Volvox
Project description:The green alga Volvox carteri is a model organism for the development of multicellularity. It has a spherical shape with a complete division of labor between around 2000 somatic cells and 16 reproductive cells. When comparing Volvox with its unicellular relative Chlamydomonas rheinhardtii, one striking observation is the similarity in the protein coding genes [1]. Additionally, Baulcombe and colleagues showed that Chlamydomonas contains functional RNAi and miRNA machineries [2]. We deep sequenced small RNAs associated with one Argonaute protein of the female Volvox strain Vol6 during its vegetative growth phase. Using these data, we established a miRNA identification pipeline that takes into account plant miRNA feature in general and also uses parameters employed in finding miRNAs in Chlamydomonas. Other small RNAs that are functionally incorporated into Ago are characterized. 1. Prochnik, S.E., et al., Genomic analysis of organismal complexity in the multicellular green alga Volvox carteri. Science, 2010. 329(5988): p. 223-6. 2. Molnar, A., et al., miRNAs control gene expression in the single-cell alga Chlamydomonas reinhardtii. Nature, 2007. 447(7148): p. 1126-9.
Project description:Purpose: Light is one of the most important environmental signal that affects the physiology and action of Volvox carteri. However, there are limited reports about the effects of UV-B irradiation on genome-wide transcriptional regulation in this organism. We surveyed the overall transcriptional responses of somatic and reproductive cells to UV-B irradiation using RNA-seq data. Methods: The somatic and reproductive cells were separated. The cell-types were treated for one hour by low-doses UV-B irradiation. Three biological replicates per cell-types (totally 12 samples) were used for RNA extraction. High-throughput RNA sequencing performed with separated-cells samples. Sequencing runs were performed on an Illumina HiSeq-2500. Transcriptome analysis was carried out in order to elucidate the effect of UV-B irradiation on whole transcriptional modification of physiological mechanisms. Results: In total, 264 and 272 million clean reads were produced in somatic and reproductive cells, respectively. The results showed that, as compared to control group, there were no differentially expressed genes in reproductive cells under treatment. However, treating the somatic cells with UV-B irradiation resulted in 126 differential genes as compared to untreated control group. Our results showed that there is light-specific transcriptional regulation in this organism. So that, different pathways were co-regulated by UV-B irradiation via the transcriptional regulation of genes encoding key enzymes in these pathways. Conclusions: Our findings showed that low UV-B irradiation influence on the cell-type specific gene expression. The findings of this study may present new insights to understand responsive mechanisms to UV-B irradiation by modulating expression of cell-type specific in the V. carteri.