1
|
Briggs DE, Caron JB. A Large Cambrian Chaetognath with Supernumerary Grasping Spines. Curr Biol 2017; 27:2536-2543.e1. [DOI: 10.1016/j.cub.2017.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/31/2017] [Accepted: 07/03/2017] [Indexed: 11/16/2022]
|
2
|
A functional difference between native and horizontally acquired genes in bdelloid rotifers. Gene 2016; 590:186-91. [PMID: 27312952 DOI: 10.1016/j.gene.2016.06.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 02/06/2023]
Abstract
The form of RNA processing known as SL trans-splicing involves the transfer of a short conserved sequence, the spliced leader (SL), from a noncoding SL RNA to the 5' ends of mRNA molecules. SL trans-splicing occurs in several animal taxa, including bdelloid rotifers (Rotifera, Bdelloidea). One striking feature of these aquatic microinvertebrates is the large proportion of foreign genes, i.e. those acquired by horizontal gene transfer from other organisms, in their genomes. However, whether such foreign genes behave similarly to native genes has not been tested in bdelloids or any other animal. We therefore used a combination of experimental and computational methods to examine whether transcripts of foreign genes in bdelloids were SL trans-spliced, like their native counterparts. We found that many foreign transcripts contain SLs, use similar splice acceptor sequences to native genes, and are able to undergo alternative trans-splicing. However, a significantly lower proportion of foreign mRNAs contains SL sequences than native transcripts. This demonstrates a novel functional difference between foreign and native genes in bdelloids and suggests that SL trans-splicing is not essential for the expression of foreign genes, but is acquired during their domestication.
Collapse
|
3
|
Lei Q, Li C, Zuo Z, Huang C, Cheng H, Zhou R. Evolutionary Insights into RNA trans-Splicing in Vertebrates. Genome Biol Evol 2016; 8:562-77. [PMID: 26966239 PMCID: PMC4824033 DOI: 10.1093/gbe/evw025] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pre-RNA splicing is an essential step in generating mature mRNA. RNA trans-splicing combines two separate pre-mRNA molecules to form a chimeric non-co-linear RNA, which may exert a function distinct from its original molecules. Trans-spliced RNAs may encode novel proteins or serve as noncoding or regulatory RNAs. These novel RNAs not only increase the complexity of the proteome but also provide new regulatory mechanisms for gene expression. An increasing amount of evidence indicates that trans-splicing occurs frequently in both physiological and pathological processes. In addition, mRNA reprogramming based on trans-splicing has been successfully applied in RNA-based therapies for human genetic diseases. Nevertheless, clarifying the extent and evolution of trans-splicing in vertebrates and developing detection methods for trans-splicing remain challenging. In this review, we summarize previous research, highlight recent advances in trans-splicing, and discuss possible splicing mechanisms and functions from an evolutionary viewpoint.
Collapse
Affiliation(s)
- Quan Lei
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| | - Cong Li
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| | - Zhixiang Zuo
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| | - Chunhua Huang
- Department of Cell Biology, College of Life Sciences, Wuhan University, P.R. China
| | - Hanhua Cheng
- Department of Cell Biology, College of Life Sciences, Wuhan University, P.R. China
| | - Rongjia Zhou
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| |
Collapse
|
4
|
Nielsen C. Evolution of deuterostomy - and origin of the chordates. Biol Rev Camb Philos Soc 2015; 92:316-325. [PMID: 26486096 DOI: 10.1111/brv.12229] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 09/15/2015] [Accepted: 09/17/2015] [Indexed: 11/30/2022]
Abstract
The chordates are usually characterized as bilaterians showing deuterostomy, i.e. the mouth developing as a new opening between the archenteron and the ectoderm, serial gill pores/slits, and the complex of chorda and neural tube. Both numerous molecular studies and studies of morphology and embryology demonstrate that the neural tube must be considered homologous to the ventral nerve cord(s) of the protostomes, but the origin of the 'new' mouth of the deuterostomes has remained enigmatic. However, deuterostomy is known to occur in several protostomian groups, such as the chaetognaths and representatives of annelids, molluscs, arthropods and priapulans. This raises the question whether the deuterostomian mouth is in fact homologous with that of the protostomes, viz. the anterior opening of the ancestral blastopore divided through lateral blastopore fusion, i.e. amphistomy. A few studies of gene expression show identical expression patterns around mouth and anus in protostomes and deuterostomes. Closer studies of the embryology of ascidians and vertebrates show that the mouth/stomodaeum differentiates from the anterior edge of the neural plate. Together this indicates that the chordate mouth has moved to the anterior edge of the blastopore, so that the anterior loop of the ancestral circumblastoporal nerve cord, which is narrow in the protostomes, has become indistinguishable. In the vertebrates, the mouth has moved further around the anterior pole to the 'ventral' side. The conclusion must be that the chordate mouth (and that of the deuterostomes in general) is homologous to the protostomian mouth and that the latest common ancestor of protostomes and deuterostomes developed through amphistomy, as suggested by the trochaea theory.
Collapse
Affiliation(s)
- Claus Nielsen
- The Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| |
Collapse
|
5
|
Shen X, Sun S, Zhao FQ, Zhang GT, Tian M, Tsang LM, Wang JF, Chu KH. Phylomitogenomic analyses strongly support the sister relationship of the Chaetognatha and Protostomia. ZOOL SCR 2015. [DOI: 10.1111/zsc.12140] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xin Shen
- Jiangsu Key Laboratory of Marine Biotechnology/Co-Innovation Center of Jiangsu Marine Bio-industry Technology; Huaihai Institute of Technology; Lianyungang 222005 China
- Beijing Institutes of Life Science; Chinese Academy of Sciences; Beijing 100101 China
- Simon F. S. Li Marine Science Laboratory; School of Life Sciences; The Chinese University of Hong Kong; Shatin Hong Kong China
| | - Song Sun
- KLMEES and JBMERS; Institute of Oceanology; Chinese Academy of Sciences; Qingdao 266071 China
| | - Fang Qing Zhao
- Beijing Institutes of Life Science; Chinese Academy of Sciences; Beijing 100101 China
| | - Guang Tao Zhang
- KLMEES and JBMERS; Institute of Oceanology; Chinese Academy of Sciences; Qingdao 266071 China
| | - Mei Tian
- Jiangsu Key Laboratory of Marine Biotechnology/Co-Innovation Center of Jiangsu Marine Bio-industry Technology; Huaihai Institute of Technology; Lianyungang 222005 China
| | - Ling Ming Tsang
- Institute of Marine Biology; National Taiwan Ocean University; Keelung 20224 Taiwan
| | - Jin Feng Wang
- Beijing Institutes of Life Science; Chinese Academy of Sciences; Beijing 100101 China
| | - Ka Hou Chu
- Simon F. S. Li Marine Science Laboratory; School of Life Sciences; The Chinese University of Hong Kong; Shatin Hong Kong China
| |
Collapse
|
6
|
Gunbin KV, Suslov VV, Turnaev II, Afonnikov DA, Kolchanov NA. Molecular evolution of cyclin proteins in animals and fungi. BMC Evol Biol 2011; 11:224. [PMID: 21798004 PMCID: PMC3162929 DOI: 10.1186/1471-2148-11-224] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 07/28/2011] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND The passage through the cell cycle is controlled by complexes of cyclins, the regulatory units, with cyclin-dependent kinases, the catalytic units. It is also known that cyclins form several families, which differ considerably in primary structure from one eukaryotic organism to another. Despite these lines of evidence, the relationship between the evolution of cyclins and their function is an open issue. Here we present the results of our study on the molecular evolution of A-, B-, D-, E-type cyclin proteins in animals and fungi. RESULTS We constructed phylogenetic trees for these proteins, their ancestral sequences and analyzed patterns of amino acid replacements. The analysis of infrequently fixed atypical amino acid replacements in cyclins evidenced that accelerated evolution proceeded predominantly during paralog duplication or after it in animals and fungi and that it was related to aromorphic changes in animals. It was shown also that evolutionary flexibility of cyclin function may be provided by consequential reorganization of regions on protein surface remote from CDK binding sites in animal and fungal cyclins and by functional differentiation of paralogous cyclins formed in animal evolution. CONCLUSIONS The results suggested that changes in the number and/or nature of cyclin-binding proteins may underlie the evolutionary role of the alterations in the molecular structure of cyclins and their involvement in diverse molecular-genetic events.
Collapse
Affiliation(s)
- Konstantin V Gunbin
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
| | - Valentin V Suslov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
| | - Igor I Turnaev
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
| | - Dmitry A Afonnikov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
- Novosibirsk state University, Pirogova, 2, Novosibirsk, Russia
| | - Nikolay A Kolchanov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
- Novosibirsk state University, Pirogova, 2, Novosibirsk, Russia
| |
Collapse
|
7
|
Abstract
Trans-splicing is the joining together of portions of two separate pre-mRNA molecules. The two distinct categories of spliceosomal trans-splicing are genic trans-splicing, which joins exons of different pre-mRNA transcripts, and spliced leader (SL) trans-splicing, which involves an exon donated from a specialized SL RNA. Both depend primarily on the same signals and components as cis-splicing. Genic trans-splicing events producing protein-coding mRNAs have been described in a variety of organisms, including Caenorhabditis elegans and Drosophila. In mammalian cells, genic trans-splicing can be associated with cancers and translocations. SL trans-splicing has mainly been studied in nematodes and trypanosomes, but there are now numerous and diverse phyla (including primitive chordates) where this type of trans-splicing has been detected. Such diversity raises questions as to the evolutionary origin of the process. Another intriguing question concerns the function of trans-splicing, as operon resolution can only account for a small proportion of the total amount of SL trans-splicing.
Collapse
Affiliation(s)
- Erika L Lasda
- University of Colorado Denver, Department of Biochemistry and Molecular Genetics; University of Colorado Boulder, Department of Molecular, Cellular, and Developmental Biology
| | | |
Collapse
|
8
|
Lasda EL, Allen MA, Blumenthal T. Polycistronic pre-mRNA processing in vitro: snRNP and pre-mRNA role reversal in trans-splicing. Genes Dev 2010; 24:1645-58. [PMID: 20624853 DOI: 10.1101/gad.1940010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Spliced leader (SL) trans-splicing in Caenorhabditis elegans attaches a 22-nucleotide (nt) exon onto the 5' end of many mRNAs. A particular class of SL, SL2, splices mRNAs of downstream operon genes. Here we use an embryonic extract-based in vitro splicing system to show that SL2 specificity information is encoded within the polycistronic pre-mRNA, and that trans-splicing specificity is recapitulated in vitro. We define an RNA sequence required for SL2 trans-splicing, the U-rich (Ur) element, through mutational analysis and bioinformatics as a short stem-loop followed by a sequence motif, UAYYUU, located approximately 50 nt upstream of the trans-splice site. Furthermore, this element is predicted in intercistronic regions of numerous operons of C. elegans and other species that use SL2 trans-splicing. We propose that the UAYYUU motif hybridizes with the 5' splice site on the SL2 RNA to recruit the SL to the pre-mRNA. In this way, the UAYYUU motif in the pre-mRNA would serve an analogous function to the similar sequence in the U1 snRNA, which binds to the 5' splice site of introns, effectively reversing the roles of snRNP and pre-mRNA in trans-splicing.
Collapse
Affiliation(s)
- Erika L Lasda
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | | | | |
Collapse
|
9
|
Harzsch S, Wanninger A. Evolution of invertebrate nervous systems: the Chaetognatha as a case study. ACTA ZOOL-STOCKHOLM 2010. [DOI: 10.1111/j.1463-6395.2009.00423.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|