scholarly journals The evolutionary fates of a large segmental duplication in mouse

2016 ◽  
Author(s):  
Andrew P Morgan ◽  
J Matthew Holt ◽  
Rachel C McMullan ◽  
Timothy A Bell ◽  
Amelia M-F Clayshulte ◽  
...  
Keyword(s):  
Segmental Duplication ◽  
Copy Number ◽  
De Novo ◽  
Allelic Diversity ◽  
Protein Coding ◽  
Wild Mice ◽  
Laboratory Populations ◽  
Gene Duplication And Loss ◽  
History Of ◽  
Mouse Reference Genome

ABSTRACTGene duplication and loss are major sources of genetic polymorphism in populations, and are important forces shaping the evolution of genome content and organization. We have reconstructed the origin and history of a 127 kbp segmental duplication, R2d, in the house mouse (Mus musculus). R2d contains a single protein-coding gene, Cwc22. De novo assembly of both the ancestral (R2d1) and the derived (R2d2) copies reveals that they have been subject to non-allelic gene conversion events spanning tens of kilobases. R2d2 is also a hotspot for structural variation: its diploid copy number ranges from zero in the mouse reference genome to more than 80 in wild mice sampled from around the globe. Hemizgyosity for high-copy-number alleles of R2d2 is associated in cis with meiotic drive, suppression of meiotic crossovers, and copy-number instability, with a mutation rate in excess of 1 per 100 transmissions in laboratory populations. We identify an additional 57 loci covering 0.8% of the mouse genome with patterns of sequence variation similar to those at R2d1 and R2d2. Our results provide a striking example of allelic diversity generated by duplication and demonstrate the value of de novo assembly in a phylogenetic context for understanding the mutational processes affecting duplicate genes.

scholarly journals A putative de novo evolved gene required for spermatid chromatin condensation in Drosophila melanogaster

2021 ◽  
Author(s):  
Emily L. Rivard ◽  
Andrew G. Ludwig ◽  
Prajal H. Patel ◽  
Anna Grandchamp ◽  
Sarah E. Arnold ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Male Fertility ◽  
De Novo ◽  
Developmental Process ◽  
Chromatin Condensation ◽  
Protein Coding ◽  
Non Coding Rna ◽  
De Novo Genes ◽  
History Of ◽  
Redundant Role

Comparative genomics has enabled the identification of genes that potentially evolved de novo from non-coding sequences. Many such genes are expressed in male reproductive tissues, but their functions remain poorly understood. To address this, we conducted a functional genetic screen of over 40 putative de novo genes with testis-enriched expression in Drosophila melanogaster and identified one gene, atlas, required for male fertility. Detailed genetic and cytological analyses show that atlas is required for proper chromatin condensation during the final stages of spermatogenesis. Atlas protein is expressed in spermatid nuclei and facilitates the transition from histone- to protamine-based chromatin packaging. Complementary evolutionary analyses revealed the complex evolutionary history of atlas. The protein-coding portion of the gene likely arose at the base of the Drosophila genus on the X chromosome but was unlikely to be essential, as it was then lost in several independent lineages. Within the last ~15 million years, however, the gene moved to an autosome, where it fused with a conserved non-coding RNA and evolved a non-redundant role in male fertility. Altogether, this study provides insight into the integration of novel genes into biological processes, the links between genomic innovation and functional evolution, and the genetic control of a fundamental developmental process, gametogenesis.

scholarly journals Transcription-induced formation of extrachromosomal DNA during yeast ageing

2019 ◽  
Author(s):  
Ryan Hull ◽  
Michelle King ◽  
Grazia Pizza ◽  
Felix Krueger ◽  
Xabier Vergara ◽  
...  
Keyword(s):  
Copy Number ◽  
De Novo ◽  
Gene Copy Number ◽  
Phenotypic Selection ◽  
Copper Resistance ◽  
Gene Copy ◽  
Dna Double Strand Breaks ◽  
Protein Coding ◽  
Gene Copy Number Variation ◽  
Number Variation

Extrachromosomal circular DNA (eccDNA) facilitates adaptive evolution by allowing rapid and extensive gene copy number variation, and is implicated in the pathology of cancer and ageing. Here, we demonstrate that yeast aged under environmental copper accumulate high levels of eccDNA containing the copper resistance gene CUP1. Transcription of CUP1 causes CUP1 eccDNA accumulation, which occurs in the absence of phenotypic selection. We have developed a sensitive and quantitative eccDNA sequencing pipeline that reveals CUP1 eccDNA accumulation on copper exposure to be exquisitely site specific, with no other detectable changes across the eccDNA complement. eccDNA forms de novo from the CUP1 locus through processing of DNA double-strand breaks (DSBs) by Sae2 / Mre11 and Mus81, and genome-wide analyses show that other protein coding eccDNA species in aged yeast share a similar biogenesis pathway. Although abundant we find that CUP1 eccDNA does not replicate efficiently, and high copy numbers in aged cells arise through frequent formation events combined with asymmetric DNA segregation. The transcriptional stimulation of CUP1 eccDNA formation shows that age-linked genetic change varies with transcription pattern, resulting in gene copy number profiles tailored by environment.

scholarly journals Comparison of Chloroplast Genomes among Species of Unisexual and Bisexual Clades of the Monocot Family Araceae

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 737 ◽  
Author(s):  
Abdullah ◽  
Claudia L. Henriquez ◽  
Furrukh Mehmood ◽  
Iram Shahzadi ◽  
Zain Ali ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
De Novo ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Trna Genes ◽  
Protein Coding ◽  
Chloroplast Genomes ◽  
History Of ◽  
And Bisexual ◽  
Contraction And Expansion

The chloroplast genome provides insight into the evolution of plant species. We de novo assembled and annotated chloroplast genomes of four genera representing three subfamilies of Araceae: Lasia spinosa (Lasioideae), Stylochaeton bogneri, Zamioculcas zamiifolia (Zamioculcadoideae), and Orontium aquaticum (Orontioideae), and performed comparative genomics using these chloroplast genomes. The sizes of the chloroplast genomes ranged from 163,770 bp to 169,982 bp. These genomes comprise 113 unique genes, including 79 protein-coding, 4 rRNA, and 30 tRNA genes. Among these genes, 17–18 genes are duplicated in the inverted repeat (IR) regions, comprising 6–7 protein-coding (including trans-splicing gene rps12), 4 rRNA, and 7 tRNA genes. The total number of genes ranged between 130 and 131. The infA gene was found to be a pseudogene in all four genomes reported here. These genomes exhibited high similarities in codon usage, amino acid frequency, RNA editing sites, and microsatellites. The oligonucleotide repeats and junctions JSB (IRb/SSC) and JSA (SSC/IRa) were highly variable among the genomes. The patterns of IR contraction and expansion were shown to be homoplasious, and therefore unsuitable for phylogenetic analyses. Signatures of positive selection were seen in three genes in S. bogneri, including ycf2, clpP, and rpl36. This study is a valuable addition to the evolutionary history of chloroplast genome structure in Araceae.

scholarly journals Analyses of transcriptomes and the first complete genome of Leucocalocybe mongolica provide new insights into phylogenetic relationships and conservation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mingzheng Duan ◽  
Haiying Bao ◽  
Tolgor Bau
Keyword(s):  
Life History ◽  
De Novo ◽  
Phylogenetic Analyses ◽  
Gene Families ◽  
Single Copy ◽  
Mushroom Species ◽  
Protein Coding ◽  
Homologous Genes ◽  
Metabolic Genes ◽  
History Of

AbstractIn this study, we report a de novo assembly of the first high-quality genome for a wild mushroom species Leucocalocybe mongolica (LM). We performed high-throughput transcriptome sequencing to analyze the genetic basis for the life history of LM. Our results show that the genome size of LM is 46.0 Mb, including 26 contigs with a contig N50 size of 3.6 Mb. In total, we predicted 11,599 protein-coding genes, of which 65.7% (7630) could be aligned with high confidence to annotated homologous genes in other species. We performed phylogenetic analyses using genes form 3269 single-copy gene families and showed support for distinguishing LM from the genus Tricholoma (L.) P.Kumm., in which it is sometimes circumscribed. We believe that one reason for limited wild occurrences of LM may be the loss of key metabolic genes, especially carbohydrate-active enzymes (CAZymes), based on comparisons with other closely related species. The results of our transcriptome analyses between vegetative (mycelia) and reproductive (fruiting bodies) organs indicated that changes in gene expression among some key CAZyme genes may help to determine the switch from asexual to sexual reproduction. Taken together, our genomic and transcriptome data for LM comprise a valuable resource for both understanding the evolutionary and life history of this species.

scholarly journals Evolution of the rapidly mutating human salivary agglutinin gene (DMBT1) and population subsistence strategy

2015 ◽  
Vol 112 (16) ◽  
pp. 5105-5110 ◽  
Author(s):  
Shamik Polley ◽  
Sandra Louzada ◽  
Diego Forni ◽  
Manuela Sironi ◽  
Theodosius Balaskas ◽  
...  
Keyword(s):  
Mutation Rate ◽  
De Novo ◽  
Scavenger Receptor ◽  
Dietary Change ◽  
De Novo Mutation ◽  
Protein Coding ◽  
History Of Agriculture ◽  
Oral Bacterium ◽  
Number Variation ◽  
History Of

The dietary change resulting from the domestication of plant and animal species and development of agriculture at different locations across the world was one of the most significant changes in human evolution. An increase in dietary carbohydrates caused an increase in dental caries following the development of agriculture, mediated by the cariogenic oral bacteriumStreptococcus mutans. Salivary agglutinin [SAG, encoded by the deleted in malignant brain tumors 1 (DMBT1) gene] is an innate immune receptor glycoprotein that binds a variety of bacteria and viruses, and mediates attachment ofS. mutansto hydroxyapatite on the surface of the tooth. In this study we show that multiallelic copy number variation (CNV) withinDMBT1is extensive across all populations and is predicted to result in between 7–20 scavenger–receptor cysteine-rich (SRCR) domains within each SAG molecule. Direct observation of de novo mutation in multigeneration families suggests these CNVs have a very high mutation rate for a protein-coding locus, with a mutation rate of up to 5% per gamete. Given that the SRCR domains bindS. mutansand hydroxyapatite in the tooth, we investigated the association of sequence diversity at the SAG-binding gene ofS. mutans, andDMBT1CNV. Furthermore, we show thatDMBT1CNV is also associated with a history of agriculture across global populations, suggesting that dietary change as a result of agriculture has shaped the pattern of CNV atDMBT1, and that theDMBT1-S. mutansinteraction is a promising model of host-pathogen-culture coevolution in humans.

scholarly journals A putative de novo evolved gene required for spermatid chromatin condensation in Drosophila melanogaster

PLoS Genetics ◽  
2021 ◽  
Vol 17 (9) ◽  
pp. e1009787
Author(s):  
Emily L. Rivard ◽  
Andrew G. Ludwig ◽  
Prajal H. Patel ◽  
Anna Grandchamp ◽  
Sarah E. Arnold ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Male Fertility ◽  
De Novo ◽  
Developmental Process ◽  
Chromatin Condensation ◽  
Protein Coding ◽  
Non Coding Rna ◽  
History Of ◽  
Redundant Role ◽  
Insight Into

Comparative genomics has enabled the identification of genes that potentially evolved de novo from non-coding sequences. Many such genes are expressed in male reproductive tissues, but their functions remain poorly understood. To address this, we conducted a functional genetic screen of over 40 putative de novo genes with testis-enriched expression in Drosophila melanogaster and identified one gene, atlas, required for male fertility. Detailed genetic and cytological analyses showed that atlas is required for proper chromatin condensation during the final stages of spermatogenesis. Atlas protein is expressed in spermatid nuclei and facilitates the transition from histone- to protamine-based chromatin packaging. Complementary evolutionary analyses revealed the complex evolutionary history of atlas. The protein-coding portion of the gene likely arose at the base of the Drosophila genus on the X chromosome but was unlikely to be essential, as it was then lost in several independent lineages. Within the last ~15 million years, however, the gene moved to an autosome, where it fused with a conserved non-coding RNA and evolved a non-redundant role in male fertility. Altogether, this study provides insight into the integration of novel genes into biological processes, the links between genomic innovation and functional evolution, and the genetic control of a fundamental developmental process, gametogenesis.

scholarly journals Comparison among the first representative chloroplast genomes of Orontium, Lasia, Zamioculcas, and Stylochaeton of the plant family Araceae: inverted repeat dynamics are not linked to phylogenetic signaling

2020 ◽  
Author(s):  
Abdullah ◽  
Claudia L. Henriquez ◽  
Furrukh Mehmood ◽  
Iram Shahzadi ◽  
Zain Ali ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
De Novo ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Trna Genes ◽  
Protein Coding ◽  
Chloroplast Genomes ◽  
History Of ◽  
Contraction And Expansion ◽  
Insight Into

AbstractThe chloroplast genome provides insight into the evolution of plant species. We de novo assembled and annotated chloroplast genomes of the first representatives of four genera representing three subfamilies: Lasia spinosa (Lasioideae), Stylochaeton bogneri, Zamioculcas zamiifolia (Zamioculcadoideae), and Orontium aquaticum (Orontioideae), and performed comparative genomics using the plastomes. The size of the chloroplast genomes ranged from 163,770–169,982 bp. These genomes comprise 114 unique genes, including 80 protein-coding, 4 rRNA, and 30 tRNA genes. These genomes exhibited high similarities in codon usage, amino acid frequency, RNA editing sites, and microsatellites. The junctions JSB (IRb/SSC) and JSA (SSC/IRa) are highly variable, as is oligonucleotide repeats content among the genomes. The patterns of inverted repeats contraction and expansion were shown to be homoplasious and therefore unsuitable for phylogenetic analyses. Signatures of positive selection were shown for several genes in S. bogneri. This study is a valuable addition to the evolutionary history of chloroplast genome structure in Araceae.

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