Genomic Expansion Across the Albumin Gene Family on Human Chromosome 4q Is Directional

1999 ◽  
Vol 380 (12) ◽  
pp. 1431-1434 ◽  
Author(s):  
Hitomi Nishio ◽  
Hamdi K. Hamdi ◽  
Achilles Dugaiczyk

Abstract The albumin gene family arose in a series of duplication events which gave rise to symmetry in its structure. The four genes are tandemly linked on human chromosome 4q in the order: 5′ ALB-5′ AFP-5′ ALF-5′ DBP-centromere, and their introns display a symmetrical and repetitive pattern that is shared by members of the gene family. These repetitive motifs provide an internal reference, allowing observations of evolutionary changes within a single line (human) of evolutionary descent. The four genes and three intergenic regions between them increase in size as they get closer to the centromere. An invasion by multiple repetitive DNA elements may account, in part, for this expansion.

2008 ◽  
Vol 21 (5) ◽  
pp. 658-670 ◽  
Author(s):  
Chang Hyun Khang ◽  
Sook-Young Park ◽  
Yong-Hwan Lee ◽  
Barbara Valent ◽  
Seogchan Kang

The avirulence (AVR) gene AVR-Pita in Magnaporthe oryzae prevents the fungus from infecting rice cultivars containing the resistance gene Pi-ta. A survey of isolates of the M. grisea species complex from diverse hosts showed that AVR-Pita is a member of a gene family, which led us to rename it to AVR-Pita1. Avirulence function, distribution, and genomic context of two other members, named AVR-Pita2 and AVR-Pita3, were characterized. AVR-Pita2, but not AVR-Pita3, was functional as an AVR gene corresponding to Pi-ta. The AVR-Pita1 and AVR-Pita2 genes were present in isolates of both M. oryzae and M. grisea, whereas the AVR-Pita3 gene was present only in isolates of M. oryzae. Orthologues of members of the AVR-Pita family could not be found in any fungal species sequenced to date, suggesting that the gene family may be unique to the M. grisea species complex. The genomic context of its members was analyzed in eight strains. The AVR-Pita1 and AVR-Pita2 genes in some isolates appeared to be located near telomeres and flanked by diverse repetitive DNA elements, suggesting that frequent deletion or amplification of these genes within the M. grisea species complex might have resulted from recombination mediated by repetitive DNA elements.


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 4 (1) ◽  
Author(s):  
Lingling DOU ◽  
Limin LV ◽  
Yangyang KANG ◽  
Ruijie TIAN ◽  
Deqing HUANG ◽  
...  

Abstract Background Calmodulin (CaM) is one of the most important Ca2+ signaling receptors because it regulates diverse physiological and biochemical reactions in plants. CaM functions by interacting with CaM-binding proteins (CaMBPs) to modulate Ca2+ signaling. IQ domain (IQD) proteins are plant-specific CaMBPs that bind to CaM by their specific CaM binding sites. Results In this study, we identified 102 GhIQD genes in the Gossypium hirsutum L. genome. The GhIQD gene family was classified into four clusters (I, II, III, and IV), and we then mapped the GhIQD genes to the G. hirsutum L. chromosomes. Moreover, we found that 100 of the 102 GhIQD genes resulted from segmental duplication events, indicating that segmental duplication is the main force driving GhIQD gene expansion. Gene expression pattern analysis showed that a total of 89 GhIQD genes expressed in the elongation stage and second cell wall biosynthesis stage of the fiber cells, suggesting that GhIQD genes may contribute to fiber cell development in cotton. In addition, we found that 20 selected GhIQD genes were highly expressed in various tissues. Exogenous application of MeJA significantly enhanced the expression levels of GhIQD genes. Conclusions Our study shows that GhIQD genes are involved in fiber cell development in cotton and are also widely induced by MeJA. Thw results provide bases to systematically characterize the evolution and biological functions of GhIQD genes, as well as clues to breed better cotton varieties in the future.


2021 ◽  
pp. 1-11
Author(s):  
David S. da Silva ◽  
Heriberto F. da Silva Filho ◽  
Marcelo B. Cioffi ◽  
Edivaldo H.C. de Oliveira ◽  
Anderson J.B. Gomes

With 82 species currently described, the genus <i>Leptodactylus</i> is the most diverse and representative one in the family Leptodactylidae. Concerning chromosomal organization, this genus represents an interesting and underexplored group since data from molecular cytogenetics are incipient, and little is known about the organization and distribution of repetitive DNA elements in the karyotypes. In this sense, this study aimed at providing a comparative analysis in 4 <i>Leptodactylus</i> species (<i>L. macrosternum, L. pentadactylus, L. fuscus,</i> and <i>Leptodactylus</i> cf<i>. podicipinus</i>), combining conventional cytogenetics (Giemsa staining, C-banding, and AgNOR staining) and mapping of molecular markers (18S rDNA, telomeric and microsatellite probes), to investigate mechanisms underlying their karyotype differentiation process. The results showed that all species had karyotypes with 2n = 22 and FN = 44, except for <i>Leptodactylus</i> cf. <i>podicipinus</i> which presented FN = 36. The 18S rDNA was observed in pair 8 of all analyzed species (corresponding to pair 4 in <i>L. pentadactylus</i>), coinciding with the secondary constrictions and AgNOR staining. FISH with microsatellite DNA probes demonstrated species-specific patterns, as well as an association of these repetitive sequences with constitutive heterochromatin blocks and ribosomal DNA clusters, revealing the dynamics of microsatellites in the genome of the analyzed species. In summary, our data demonstrate an ongoing process of genomic divergence inside species with almost similar karyotype, driven most likely by a series of pericentric inversions, followed by differential accumulation of repetitive sequences.


2022 ◽  
Vol 23 (2) ◽  
pp. 614
Author(s):  
Weiqi Sun ◽  
Mengdi Li ◽  
Jianbo Wang

Brassica napus and its diploid progenitors (B. rapa and B. oleracea) are suitable for studying the problems associated with polyploidization. As an important anti-stress protein, RCI2 proteins widely exist in various tissues of plants, and are crucial to plant growth, development, and stress response. In this study, the RCI2 gene family was comprehensively identified and analyzed, and 9, 9, and 24 RCI2 genes were identified in B. rapa, B. oleracea, and B. napus, respectively. Phylogenetic analysis showed that all of the identified RCI2 genes were divided into two groups, and further divided into three subgroups. Ka/Ks analysis showed that most of the identified RCI2 genes underwent a purifying selection after the duplication events. Moreover, gene structure analysis showed that the structure of RCI2 genes is largely conserved during polyploidization. The promoters of the RCI2 genes in B. napus contained more cis-acting elements, which were mainly involved in plant development and growth, plant hormone response, and stress responses. Thus, B. napus might have potential advantages in some biological aspects. In addition, the changes of RCI2 genes during polyploidization were also discussed from the aspects of gene number, gene structure, gene relative location, and gene expression, which can provide reference for future polyploidization analysis.


2021 ◽  
Vol 9 ◽  
Author(s):  
Abdullah ◽  
Sahar Faraji ◽  
Parviz Heidari ◽  
Péter Poczai

The benzyl alcohol O-acetyl transferase, anthocyanin O-hydroxycinnamoyl transferase, N-hydroxycinnamoyl anthranilate benzoyl transferase, and deacetylvindoline 4-O-acetyltransferase (BAHD) enzymes play a critical role in regulating plant metabolites and affecting cell stability. In the present study, members of the BAHD gene family were recognized in the genome of Theobroma cacao and characterized using various bioinformatics tools. We found 27 non-redundant putative tcBAHD genes in cacao for the first time. Our findings indicate that tcBAHD genes are diverse based on sequence structure, physiochemical properties, and function. When analyzed with BAHDs of Gossypium raimondii and Corchorus capsularis clustered into four main groups. According to phylogenetic analysis, BAHD genes probably evolved drastically after their divergence. The divergence time of duplication events with purifying selection pressure was predicted to range from 1.82 to 15.50 MYA. Pocket analysis revealed that serine amino acid is more common in the binding site than other residuals, reflecting its key role in regulating the activity of tcBAHDs. Furthermore, cis-acting elements related to the responsiveness of stress and hormone, particularly ABA and MeJA, were frequently observed in the promoter region of tcBAHD genes. RNA-seq analysis further illustrated that tcBAHD13 and tcBAHD26 are involved in response to Phytophthora megakarya fungi. In conclusion, it is likely that evolutionary processes, such as duplication events, have caused high diversity in the structure and function of tcBAHD genes.


1991 ◽  
Vol 42 (2) ◽  
pp. 243-249 ◽  
Author(s):  
D. R SIBSON ◽  
S. G. HUGHES ◽  
J. A. BRYANT ◽  
P. N. FITCHETT

Genome ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 138-142 ◽  
Author(s):  
Michael S. Zwick ◽  
Robert E. Hanson ◽  
M. Nurul Islam-Faridi ◽  
David M. Stelly ◽  
Rod A. Wing ◽  
...  

In situ hybridization (ISH) for the detection of single- or low-copy sequences, particularly large DNA fragments cloned into YAC or BAC vectors, generally requires the suppression or "blocking" of highly-repetitive DNAs. C0t-1 DNA is enriched for repetitive DNA elements, high or moderate in copy number, and can therefore be used more effectively than total genomic DNA to prehybridize and competitively hybridize repetitive elements that would otherwise cause nonspecific hybridization. C0t-1 DNAs from several mammalian species are commercially available, however, none is currently available for plants to the best of our knowledge. We have developed a simple 1-day procedure to generate C0t-1 DNA without the use of specialized equipment.Key words: C0t-1 DNA, in situ hybridization, BACs, plants.


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