scholarly journals Three amphioxus reference genomes reveal gene and chromosome evolution of chordates

2022 ◽  
Author(s):  
Huang Zhen ◽  
Luohao Xu ◽  
Cheng Cai ◽  
Yitao Zhou ◽  
Jing Liu ◽  
...  

The slow-evolving invertebrate amphioxus has an irreplaceable role in advancing our understanding into the vertebrate origin and innovations. Here we resolve the nearly complete chromosomal genomes of three amphioxus species, one of which best recapitulates the 17 chordate ancestor linkage groups. We reconstruct the fusions, retention or rearrangements between descendants of whole genome duplications (WGDs), which gave rise to the extant microchromosomes likely existed in the vertebrate ancestor. Similar to vertebrates, the amphioxus genome gradually establishes its 3D chromatin architecture at the onset of zygotic activation, and forms two topologically associated domains at the Hox gene cluster. We find that all three amphioxus species have ZW sex chromosomes with little sequence differentiation, and their putative sex-determining regions are nonhomologous to each other. Our results illuminate the unappreciated interspecific diversity and developmental dynamics of amphioxus genomes, and provide high-quality references for understanding the mechanisms of chordate functional genome evolution.

2021 ◽  
Author(s):  
Caelinn James ◽  
Marco Trevisan-Herraz ◽  
Daniel Rico

Topologically associated domains (TADs) are interaction sub-networks of 3D genomes. TAD boundaries frequently coincide with genome breaks while their deletion is under negative selection, suggesting that TADs act as modules facilitating genome rearrangements and metazoan evolution. However, the role of TADs in the evolution of gene regulation and essentiality is not well understood. Here, we show that TADs play a role organising ancestral functions and evolutionary novelty. We discovered that genes co-localise by evolutionary age in the human and mouse genomes, resulting in TADs that have different proportions of younger and older genes. A major transition in the TAD age co-localisation patterns is observed between the genes born as a result of the vertebrate whole genome duplications (WGDs) or before, and those born afterwards. We also found that primate- and rodent-specific genes are more frequently essential when they are located in 'aged' TADs and connected to genes that have not duplicated since the WGD. Our data suggests that evolutionary success of recent genes may increase when located in functionally relevant TADs with established regulatory networks.


Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1190
Author(s):  
Yuqi Huang ◽  
Minghao Sun ◽  
Lenan Zhuang ◽  
Jin He

Androgen-inducible genes (AIGs), which can be regulated by androgen level, constitute a group of genes characterized by the presence of the AIG/FAR-17a domain in its protein sequence. Previous studies on AIGs demonstrated that one member of the gene family, AIG1, is involved in many biological processes in cancer cell lines and that ADTRP is associated with cardiovascular diseases. It has been shown that the numbers of AIG paralogs in humans, mice, and zebrafish are 2, 2, and 3, respectively, indicating possible gene duplication events during vertebrate evolution. Therefore, classifying subgroups of AIGs and identifying the homologs of each AIG member are important to characterize this novel gene family further. In this study, vertebrate AIGs were phylogenetically grouped into three major clades, ADTRP, AIG1, and AIG-L, with AIG-L also evident in an outgroup consisting of invertebrsate species. In this case, AIG-L, as the ancestral AIG, gave rise to ADTRP and AIG1 after two rounds of whole-genome duplications during vertebrate evolution. Then, the AIG family, which was exposed to purifying forces during evolution, lost or gained some of its members in some species. For example, in eutherians, Neognathae, and Percomorphaceae, AIG-L was lost; in contrast, Salmonidae and Cyprinidae acquired additional AIG copies. In conclusion, this study provides a comprehensive molecular phylogenetic analysis of vertebrate AIGs, which can be employed for future functional characterization of AIGs.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hua Sun ◽  
Song Cao ◽  
R. Jay Mashl ◽  
Chia-Kuei Mo ◽  
Simone Zaccaria ◽  
...  

AbstractDevelopment of candidate cancer treatments is a resource-intensive process, with the research community continuing to investigate options beyond static genomic characterization. Toward this goal, we have established the genomic landscapes of 536 patient-derived xenograft (PDX) models across 25 cancer types, together with mutation, copy number, fusion, transcriptomic profiles, and NCI-MATCH arms. Compared with human tumors, PDXs typically have higher purity and fit to investigate dynamic driver events and molecular properties via multiple time points from same case PDXs. Here, we report on dynamic genomic landscapes and pharmacogenomic associations, including associations between activating oncogenic events and drugs, correlations between whole-genome duplications and subclone events, and the potential PDX models for NCI-MATCH trials. Lastly, we provide a web portal having comprehensive pan-cancer PDX genomic profiles and source code to facilitate identification of more druggable events and further insights into PDXs’ recapitulation of human tumors.


Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1375
Author(s):  
Larisa S. Biltueva ◽  
Dmitry Yu. Prokopov ◽  
Svetlana A. Romanenko ◽  
Elena A. Interesova ◽  
Manfred Schartl ◽  
...  

Polyploid genomes present a challenge for cytogenetic and genomic studies, due to the high number of similar size chromosomes and the simultaneous presence of hardly distinguishable paralogous elements. The karyotype of the Siberian sturgeon (Acipenser baerii) contains around 250 chromosomes and is remarkable for the presence of paralogs from two rounds of whole-genome duplications (WGD). In this study, we applied the sterlet-derived acipenserid satDNA-based whole chromosome-specific probes to analyze the Siberian sturgeon karyotype. We demonstrate that the last genome duplication event in the Siberian sturgeon was accompanied by the simultaneous expansion of several repetitive DNA families. Some of the repetitive probes serve as good cytogenetic markers distinguishing paralogous chromosomes and detecting ancestral syntenic regions, which underwent fusions and fissions. The tendency of minisatellite specificity for chromosome size groups previously observed in the sterlet genome is also visible in the Siberian sturgeon. We provide an initial physical chromosome map of the Siberian sturgeon genome supported by molecular markers. The application of these data will facilitate genomic studies in other recent polyploid sturgeon species.


Cell Reports ◽  
2012 ◽  
Vol 2 (5) ◽  
pp. 1387-1398 ◽  
Author(s):  
Param Priya Singh ◽  
Séverine Affeldt ◽  
Ilaria Cascone ◽  
Rasim Selimoglu ◽  
Jacques Camonis ◽  
...  

1998 ◽  
Vol 9 (9) ◽  
pp. 721-734 ◽  
Author(s):  
Claude Szpirer ◽  
Josiane Szpirer ◽  
Pascale Van Vooren ◽  
Fadel Tissir ◽  
Jason S. Simon ◽  
...  

Genes ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 563 ◽  
Author(s):  
Anna Szczepaniak ◽  
Michał Książkiewicz ◽  
Jan Podkowiński ◽  
Katarzyna Czyż ◽  
Marek Figlerowicz ◽  
...  

Acetyl-coenzyme A carboxylase (ACCase, E.C.6.4.1.2) catalyzes acetyl-coenzyme A carboxylation to malonyl coenzyme A. Plants possess two distinct ACCases differing by cellular compartment and function. Plastid ACCase contributes to de novo fatty acid synthesis, whereas cytosolic enzyme to the synthesis of very long chain fatty acids, phytoalexins, flavonoids, and anthocyanins. The narrow leafed lupin (Lupinus angustifolius L.) represents legumes, a plant family which evolved by whole-genome duplications (WGDs). The study aimed on the contribution of these WGDs to the multiplication of ACCase genes and their further evolutionary patterns. The molecular approach involved bacterial artificial chromosome (BAC) library screening, fluorescent in situ hybridization, linkage mapping, and BAC sequencing. In silico analysis encompassed sequence annotation, comparative mapping, selection pressure calculation, phylogenetic inference, and gene expression profiling. Among sequenced legumes, the highest number of ACCase genes was identified in lupin and soybean. The most abundant plastid ACCase subunit genes were accB. ACCase genes in legumes evolved by WGDs, evidenced by shared synteny and Bayesian phylogenetic inference. Transcriptional activity of almost all copies was confirmed. Gene duplicates were conserved by strong purifying selection, however, positive selection occurred in Arachis (accB2) and Lupinus (accC) lineages, putatively predating the WGD event(s). Early duplicated accA and accB genes underwent transcriptional sub-functionalization.


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