Genomic organization and expression analysis of the mouse qkI locus qkI gene, exon 1), AF090392(exon 2), AF090393(exon 3), AF090394(exon 4), AF090395(exon 5), AF090396(exon 6), AF090397(exon 7a), AF090398(exon 7b), AF090399(exon 7c), AF090400(exon 8), AF090401(exon 9), AF090402(5kb-A mRNA) AF090403(5kb-B mRNA), AF090404(6kb mRNA), AF091047(7kb-B mRNA).-->

1999 ◽  
Vol 10 (7) ◽  
pp. 662-669 ◽  
Author(s):  
Tatsuya Kondo *, ‡ , Tokiko Furuta ◽  
Kanae Mitsunaga ◽  
Thomas A. Ebersole ◽  
Motoaki Shichiri ◽  
Jiang Wu ◽  
...  
1990 ◽  
Vol 10 (5) ◽  
pp. 2133-2144 ◽  
Author(s):  
M E Gallego ◽  
B Nadal-Ginard

The mechanisms involved in the selective joining of appropriate 5' and 3' splice sites are still poorly understood in both constitutive and alternatively spliced genes. With two promoters associated with different exons, the myosin light-chain 1/3 gene generates two pre-mRNAs that also differ by the use of a pair of internal exons, 3 and 4, that are spliced in a mutually exclusive fashion. When the promoter upstream from exon 1 is used, only exon 4 is included. If the promoter upstream from exon 2 is used, only exon 3 is included. In an attempt to understand the molecular basis for the mutually exclusive behavior of these two exons and the basis of their specific selection, a number of minigene constructs containing exons 3 and 4 were tested in a variety of homologous or heterologous cis and trans environments. The results demonstrate that the mutually exclusive behavior of myosin light-chain exons 3 and 4 and selection between the two exons are cis regulated and are affected by the nature of the flanking sequences. Both exons competed for the common flanking 5' and 3' splice sites. Flanking exons were found that favored inclusion into mature mRNA of exon 3, exon 4, both, or neither, suggesting a specific cooperative interaction between certain 5' and 3' splice sites. Thus, alternative splicing of myosin light-chain 1/3 pre-mRNAs is regulated in cis by a hierarchy of compatibilities between pairs of 5' and 3' splice sites.


1990 ◽  
Vol 10 (5) ◽  
pp. 2133-2144
Author(s):  
M E Gallego ◽  
B Nadal-Ginard

The mechanisms involved in the selective joining of appropriate 5' and 3' splice sites are still poorly understood in both constitutive and alternatively spliced genes. With two promoters associated with different exons, the myosin light-chain 1/3 gene generates two pre-mRNAs that also differ by the use of a pair of internal exons, 3 and 4, that are spliced in a mutually exclusive fashion. When the promoter upstream from exon 1 is used, only exon 4 is included. If the promoter upstream from exon 2 is used, only exon 3 is included. In an attempt to understand the molecular basis for the mutually exclusive behavior of these two exons and the basis of their specific selection, a number of minigene constructs containing exons 3 and 4 were tested in a variety of homologous or heterologous cis and trans environments. The results demonstrate that the mutually exclusive behavior of myosin light-chain exons 3 and 4 and selection between the two exons are cis regulated and are affected by the nature of the flanking sequences. Both exons competed for the common flanking 5' and 3' splice sites. Flanking exons were found that favored inclusion into mature mRNA of exon 3, exon 4, both, or neither, suggesting a specific cooperative interaction between certain 5' and 3' splice sites. Thus, alternative splicing of myosin light-chain 1/3 pre-mRNAs is regulated in cis by a hierarchy of compatibilities between pairs of 5' and 3' splice sites.


2021 ◽  
pp. 106689692110219
Author(s):  
Rui Pan ◽  
Ziyu Wang ◽  
Xiaotong Wang ◽  
Ru Fang ◽  
Qiuyuan Xia ◽  
...  

Undifferentiated small round cell sarcoma (USRCS) represents a highly heterogeneous group of tumors. A variety of specific gene fusions of USRCS have been reported, including CIC–FOXO4, CIC–NUTM1, BCOR–MAML3, and ZC3H7B–BCOR. Here we report a case of sarcoma harboring a rare recurrent CRTC1–SS18 gene fusion, which was considered as USRCS previously. This sarcoma was composed of nests of small round cells encapsulated in a fibrous stroma. Foci of necrosis and hemorrhage were observed in the tumor. Immunohistochemistry for anaplastic lymphoma kinase showed diffuse positivity. RNA-seq results revealed a chromosomal translocation of CRTC1 gene exon 1 on chromosome 19 with SS18 gene exon 2 on chromosome 18. Thereafter, fluorescence in-situ hybridization confirmed the presence of SS18 gene and CRTC1 gene break-apart, which manifested as the splitting of red and green signals into 2 parts. A previous study showed that CRTC1–SS18 fusion sarcoma and EWSR1–CREB1 fusion angiomatoid fibrous histiocytoma were clustered close in the expression profile. However, whether CRTC1–SS18 fusion sarcomas represent a high malignancy has been a matter of debate. Our study is a worthy addition to the series of rare rearrangements associated with sarcomas and may be of therapeutic relevance.


Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 888
Author(s):  
Mohammed A. Ibrahim Al-Obaide ◽  
Kalkunte S. Srivenugopal

Background: The therapeutically important DNA repair gene O6-methylguanine DNA methyltransferase (MGMT) is silenced by promoter methylation in human brain cancers. The co-players/regulators associated with this process and the subsequent progression of MGMT gene transcription beyond the non-coding exon 1 are unknown. As a follow-up to our recent finding of a predicted second promoter mapped proximal to the exon 2 [Int. J. Mol. Sci.2021, 22(5), 2492], we addressed its significance in MGMT transcription. Methods: RT-PCR, RT q-PCR, and nuclear run-on transcription assays were performed to compare and contrast the transcription rates of exon 1 and exon 2 of the MGMT gene in glioblastoma cells. Results: Bioinformatic characterization of the predicted MGMT exon 2 promoter showed several consensus TATA box and INR motifs and the absence of CpG islands in contrast to the established TATA-less, CpG-rich, and GAF-bindable exon 1 promoter. RT-PCR showed very weak MGMT-E1 expression in MGMT-proficient SF188 and T98G GBM cells, compared to active transcription of MGMT-E2. In the MGMT-deficient SNB-19 cells, the expression of both exons remained weak. The RT q-PCR revealed that MGMT-E2 and MGMT-E5 expression was about 80- to 175-fold higher than that of E1 in SF188 and T98G cells. Nuclear run-on transcription assays using bromo-uridine immunocapture followed by RT q-PCR confirmed the exceptionally lower and higher transcription rates for MGMT-E1 and MGMT-E2, respectively. Conclusions: The results provide the first evidence for transcriptional pausing at the promoter 1- and non-coding exon 1 junction of the human MGMT gene and its activation/elongation through the protein-coding exons 2 through 5, possibly mediated by a second promoter. The findings offer novel insight into the regulation of MGMT transcription in glioma and other cancer types.


Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Lilia González-Cerón ◽  
José Cebrián-Carmona ◽  
Concepción M. Mesa-Valle ◽  
Federico García-Maroto ◽  
Frida Santillán-Valenzuela ◽  
...  

Plasmodium vivax Cysteine-Rich Protective Antigen (CyRPA) is a merozoite protein participating in the parasite invasion of human reticulocytes. During natural P. vivax infection, antibody responses against PvCyRPA have been detected. In children, low anti-CyRPA antibody titers correlated with clinical protection, which suggests this protein as a potential vaccine candidate. This work analyzed the genetic and amino acid diversity of pvcyrpa in Mexican and global parasites. Consensus coding sequences of pvcyrpa were obtained from seven isolates. Other sequences were extracted from a repository. Maximum likelihood phylogenetic trees, genetic diversity parameters, linkage disequilibrium (LD), and neutrality tests were analyzed, and the potential amino acid polymorphism participation in B-cell epitopes was investigated. In 22 sequences from Southern Mexico, two synonymous and 21 nonsynonymous mutations defined nine private haplotypes. These parasites had the highest LD-R2 index and the lowest nucleotide diversity compared to isolates from South America or Asia. The nucleotide diversity and Tajima’s D values varied across the coding gene. The exon-1 sequence had greater diversity and Rm values than those of exon-2. Exon-1 had significant positive values for Tajima’s D, β-α values, and for the Z (HA: dN > dS) and MK tests. These patterns were similar for parasites of different origin. The polymorphic amino acid residues at PvCyRPA resembled the conformational B-cell peptides reported in PfCyRPA. Diversity at pvcyrpa exon-1 is caused by mutation and recombination. This seems to be maintained by balancing selection, likely due to selective immune pressure, all of which merit further study.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 668
Author(s):  
Zhi-gang Niu ◽  
Jin Qin ◽  
Yao Jiang ◽  
Xiang-Dong Ding ◽  
Yu-gong Ding ◽  
...  

The Bone Morphogenetic Protein 15 (BMP15) gene is known to have multiple single-nucleotide polymorphism sites associated with sheep fecundity. This study used gene sequence analysis and mutation detection assays for BMP15 by using 205 blood samples of ewes with known lambing records. Sequence analysis showed that mutation B1 missed the CTT base in exon 1 at positions 28–30, leading to a leucine deletion in the BMP15 protein. Litter size of ewes differed significantly between BB and B+ genotypes of B1 (p < 0.05); however, the differences between wild genotype (++) and homozygous (BB) or wild genotype (++) and heterozygous (B+) were not significant (p > 0.05). Another mutation, T755C, is a T-to-C base change at position 755 of exon 2, resulting in leucine replacement by proline at this position of the BMP15 protein (p.L252P). Two genotypes were identified in the flock: heterozygous (E+) and wild-type genotype (++). Ewes with heterozygous (E+) p.L252P had significantly larger litter sizes than those with the wild-type genotype (p < 0.05). Comprehensive analysis suggests that p.L252P is a mutation that affects fecundity in Cele black sheep.


1998 ◽  
Vol 83 (10) ◽  
pp. 3604-3608
Author(s):  
Gisah A. Carvalho ◽  
Roy E. Weiss ◽  
Samuel Refetoff

Fourteen T4-binding globulin (TBG) variants have been identified at the gene level. They are all located in the coding region of the gene and 6 produce complete deficiency of TBG (TBG-CD). We now describe the first mutation in a noncoding region producing TBG-CD. The proband was treated for over 20 yr with L-T4 because of fatigue associated with a low concentration of serum total T4. Fifteen family members were studied showing low total T4 inherited as an X chromosome-linked trait, and affected males had undetectable TBG in serum. Sequencing of the entire coding region and promoter of the TBG gene revealed no abnormality. However, an A to G transition was found in the acceptor splice junction of intron II that produced a new HaeIII restriction site cosegregating with the TBG-CD phenotype. Sequencing exon 1 to exon 3 of TBG complementary DNA reverse transcribed from messenger RNA of skin fibroblasts from an affected male, confirmed a shift in the ag acceptor splice site. This results in the insertion of a G in exon 2 and causes a frameshift and a premature stop at codon 195. This early termination of translation predicts a truncated TBG lacking 201 amino acids.


2002 ◽  
Vol 368 (3) ◽  
pp. 753-760 ◽  
Author(s):  
Alexandre GARIN ◽  
Philippe PELLET ◽  
Philippe DETERRE ◽  
Patrice DEBRÉ ◽  
Christophe COMBADIÈRE

We have previously shown that reduced expression of the fractalkine receptor, CX3CR1, is correlated with rapid HIV disease progression and with reduced susceptibility to acute coronary events. In order to elucidate the mechanisms underlying transcriptional regulation of CX3CR1 expression, we structurally and functionally characterized the CX3CR1 gene. It consists of four exons and three introns spanning over 18kb. Three transcripts are produced by splicing the three untranslated exons with exon 4, which contains the complete open reading frame. The transcript predominantly found in leucocytes corresponds to the splicing of exon 2 with exon 4. Transcripts corresponding to splicing of exons 1 and 4 are less abundant in leucocytes and splicing of exons 3 and 4 are rare longer transcripts. A constitutive promoter activity was found in the regions extending upstream from untranslated exons 1 and 2. Interestingly, exons 1 and 2 enhanced the activity of their respective promoters in a cell-specific manner. These data show that the CX3CR1 gene is controlled by three distinct promoter regions, which are regulated by their respective untranslated exons and that lead to the transcription of three mature messengers. This highly complex regulation may allow versatile and precise expression of CX3CR1 in various cell types.


Author(s):  
O.D. Biriukova ◽  
T.M. Suprovych ◽  
M.P. Suprovych ◽  
S.V. Laiter-Moskaliuk ◽  
I.O. Chornyi

Molecular genetic markers can detect polymorphism at the DNA level. This feature determines the possibility of their widespread use in genetics and breeding. Alleles of the BoLA-DRB3 gene (exon 2) can act as such markers if a statically significant association between the disease and the allele is established. The presence of such DNA markers in the genotype of animals makes it possible to judge the likelihood of disease in postnatal ontogenesis immediately after the birth of a heifer, based on which we can conclude about the conditions of further use of the animal in the main herd. According to the results of studying the polymorphism of the BoLA-DRB3 gene in cows of the Ukrainian black and white dairy breed resistant and susceptible to necrobacteriosis, four "informative" alleles were revealed. Two of them *03 and *22 are associated with resistance, and the other two - *16 and *23 with susceptibility to necrobacteriosis. The presence of these alleles in the genotype of the animal is determined by testing performed by PCR-RFLP. The method is time consuming, labor intensive and costly. To simplify it, the following technique is proposed. Restriction fragments of alleles *03, *16, *22 and *23 for endocluases RsaI, XhoII and HaeIII have the following DNA patterns: bbb, jbd, mba and nba. Due to the peculiarity of the restriction fragments, which is that endonuclease XhoII reveals in these alleles only one pattern b with length of 284 bp, the process of determining informative alleles can be simplified. Isolation of DNA from blood samples and amplification of a fragment of the BoLA-DRB3.2 gene with a size of 284 bp is carried out according to the established technique. Next, the restriction of the fragment by endonuclease XhoII and sampling having a pattern b. Selected samples are treated with RsaI endonuclease and only those with patterns b, j, m and n remain. The next step is to restrict the selected samples with HaeIII endonuclease and select heifers with bbb (*03) and nba (*23) genotypes. After the first restriction, blood samples without pattern b are eliminated from the experimental sample; after the second – two alleles with patterns RsaI + XhoII jb (*16) and mb (*22) are unambiguously determined, after the third – genotypes bbb and nba, which correspond to alleles *03 and *23. In total, only 75% of blood samples are typed, which reduces the material consumption, time and cost of work to identify heifers genetically susceptible (resistant) to necrobacteriosis.


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