Origin and evolution of a new exon of 14-3-3ξ in bees and phylogenetic analysis

Genome ◽  
2013 ◽  
Vol 56 (4) ◽  
pp. 233-237
Author(s):  
Leilei Zhan ◽  
Chao Jiang

Mutually exclusive splicing, one type of alternative splicing, involves selection of alternatively spliced exons arranged in tandem and creates protein products with substitution of one segment of the amino acid sequence for another. Previous studies revealed that exon 5 of 14-3-3ξ from Apis mellifera (western honeybee) had three mutually exclusive exons, while orthologous exon of Nasonia vitripennis (parasitic wasp) had only two, suggesting that cases of exon gain or loss might have happened during the evolution of hymenopteran species. In the current study, we annotated and analyzed the 14-3-3ξ genes from 20 hymenopteran species successfully, and the results of phylogenetic analysis revealed the presence of a new mutually exclusive exon in corbiculate bees. In addition, we found that duplication via staggered homologous recombination was responsible for the origin of the new exon.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kantamas Apitanyasai ◽  
Shiao-Wei Huang ◽  
Tze Hann Ng ◽  
Shu-Ting He ◽  
Yu-Hsun Huang ◽  
...  

Abstract Using two advanced sequencing approaches, Illumina and PacBio, we derive the entire Dscam gene from an M2 assembly of the complete Penaeus monodon genome. The P. monodon Dscam (PmDscam) gene is ~266 kbp, with a total of 44 exons, 5 of which are subject to alternative splicing. PmDscam has a conserved architectural structure consisting of an extracellular region with hypervariable Ig domains, a transmembrane domain, and a cytoplasmic tail. We show that, contrary to a previous report, there are in fact 26, 81 and 26 alternative exons in N-terminal Ig2, N-terminal Ig3 and the entirety of Ig7, respectively. We also identified two alternatively spliced exons in the cytoplasmic tail, with transmembrane domains in exon variants 32.1 and 32.2, and stop codons in exon variants 44.1 and 44.2. This means that alternative splicing is involved in the selection of the stop codon. There are also 7 non-constitutive cytoplasmic tail exons that can either be included or skipped. Alternative splicing and the non-constitutive exons together produce more than 21 million isoform combinations from one PmDscam locus in the P. monodon gene. A public-facing database that allows BLAST searches of all 175 exons in the PmDscam gene has been established at http://pmdscam.dbbs.ncku.edu.tw/.


Genetics ◽  
1996 ◽  
Vol 143 (2) ◽  
pp. 961-972 ◽  
Author(s):  
Marie-Jeanne Perrot-Minnot ◽  
Li Rong Guo ◽  
John H Werren

Abstract Wolbachia are cytoplasmically inherited bacteria responsible for reproductive incompatibility in a wide range of insects. There has been little exploration, however, of within species Wolbachia polymorphisms and their effects on compatibility. Here we show that some strains of the parasitic wasp Nasonia vitripennis are infected with two distinct bacterial strains (A and B) whereas others are singly infected (A or B). Double and single infections are confirmed by both PCR amplification and Southern analysis of genomic DNA. Furthermore, it is shown that prolonged larval diapause (the overwintering stage of the wasp) of a double-infected strain can lead to stochastic loss of one or both bacterial strains. After diapause of a double-infected line, sublines were produced with AB, A only, B only or no Wolbachia. A and B sublines are bidirectionally incompatible, whereas males from AB lines are unidirectionally incompatible with females of A and B sublines. Results therefore show rapid development of bidirectional incompatibility within a species due to segregation of associated symbiotic bacteria.


Author(s):  
Andrea Highfield ◽  
Angela Ward ◽  
Richard Pipe ◽  
Declan C. Schroeder

Abstract Twelve hyper-β carotene-producing strains of algae assigned to the genus Dunaliella salina have been isolated from various hypersaline environments in Israel, South Africa, Namibia and Spain. Intron-sizing of the SSU rDNA and phylogenetic analysis of these isolates were undertaken using four commonly employed markers for genotyping, LSU rDNA, ITS, rbcL and tufA and their application to the study of Dunaliella evaluated. Novel isolates have been identified and phylogenetic analyses have shown the need for clarification on the taxonomy of Dunaliella salina. We propose the division of D. salina into four sub-clades as defined by a robust phylogeny based on the concatenation of four genes. This study further demonstrates the considerable genetic diversity within D. salina and the potential of genetic analyses for aiding in the selection of prospective economically important strains.


2008 ◽  
Vol 83 (1) ◽  
pp. 94-98 ◽  
Author(s):  
Vasily E. Ramensky ◽  
Ramil N. Nurtdinov ◽  
Alexei D. Neverov ◽  
Andrei A. Mironov ◽  
Mikhail S. Gelfand

1993 ◽  
Vol 13 (9) ◽  
pp. 5301-5314 ◽  
Author(s):  
G S Huh ◽  
R O Hynes

We have investigated the regulation of splicing of one of the alternatively spliced exons in the rat fibronectin gene, the EIIIB exon. This 273-nucleotide exon is excluded by some cells and included to various degrees by others. We find that EIIIB is intrinsically poorly spliced and that both its exon sequences and its splice sites contribute to its poor recognition. Therefore, cells which recognize the EIIIB exon must have mechanisms for improving its splicing. Furthermore, in order for EIIB to be regulated, a balance must exist between the EIIIB splice sites and those of its flanking exons. Although the intron upstream of EIIIB does not appear to play a role in the recognition of EIIIB for splicing, the intron downstream contains sequence elements which can promote EIIIB recognition in a cell-type-specific fashion. These elements are located an unusually long distance from the exon that they regulate, more than 518 nucleotides downstream from EIIIB, and may represent a novel mode of exon regulation.


Genetics ◽  
1990 ◽  
Vol 124 (2) ◽  
pp. 385-396 ◽  
Author(s):  
S H Orzack

Abstract Correlation and regression analyses indicate that isofemale strains extracted from a population of the parasitic wasp, Nasonia vitripennis, differ in the fit of their second sex ratios (those produced in previously parasitized hosts) to the predictions of the theory of optimal facultative sex ratio adjustment. Under the theory's simple assumptions about population structure, there is significant heterogeneity of fitnesses among the isofemale strains. The reasons underlying these types of heterogeneity must be understood before we can make statements about the nature of sex ratio evolution in this species. These results suggest that comparative analyses are essential for testing the qualitative predictions of optimality models.


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