A novel HLA-A null allele (A*02:395N) with stop codon in exon 2 generated by single nucleotide exchange

2013 ◽  
Vol 81 (6) ◽  
pp. 451-452 ◽  
Author(s):  
P. Jindra ◽  
P. Venigová ◽  
L. Houdová ◽  
K. Steinerová
2011 ◽  
Vol 78 (6) ◽  
pp. 463-464 ◽  
Author(s):  
A. Zimmerman ◽  
L. S. Spruit ◽  
W. Herczyk ◽  
S. R. Marino

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 873-877
Author(s):  
Allan L. Freeth ◽  
John B. Gibson ◽  
Ann Verona Wilks

The DNA sequence of a naturally occurring alcohol dehydrogenase null activity allele, AdhnAC14, has eight extra nucleotides (in two groups of four) in the second intron, commencing six bases 3′ from the 5′ splice site. A stop codon was also found in exon 2. S1 nuclease protection experiments have shown that the insertions in intron 2 disrupt the correct splicing of intron 2. The null allele produces a transcript approximately 100 bases longer than the normal mature adult transcript, and the amount of the null allele transcript is only about 10% of the normal level.Key words: alcohol dehydrogenase, null allele, splicing, S1 nuclease, Drosophila melanogaster.


2017 ◽  
Vol 29 (12) ◽  
pp. 2411 ◽  
Author(s):  
Xiuge Wang ◽  
Xiaohui Cui ◽  
Yan Zhang ◽  
Haisheng Hao ◽  
Zhihua Ju ◽  
...  

RAB, member of RAS oncogene family like 2B (RABL2B) is a member of a poorly characterised clade of the RAS GTPase superfamily, which plays an essential role in male fertility, sperm intraflagellar transport and tail assembly. In the present study, we identified a novel RABL2B splice variant in bovine testis and spermatozoa. This splice variant, designated RABL2B-TV, is characterised by exon 2 skipping. Moreover, a single nucleotide polymorphism (SNP), namely c.125G>A, was found within the exonic splicing enhancer (ESE) motif, indicating that the SNP caused the production of the RABL2B-TV aberrant splice variant. This was demonstrated by constructing a pSPL3 exon capturing vector with different genotypes and transfecting these vectors into murine Leydig tumour cell line (MLTC-1) cells. Expression of the RABL2B-TV transcript was lower in semen from high- versus low-performance bulls. Association analysis showed that sperm deformity rate was significantly lower in Chinese Holstein bulls with the GG or GA genotype than in bulls with the AA genotype (P < 0.05). In addition, initial sperm motility was significantly higher in individuals with the GG or GA genotype than in individuals with the AA genotype (P < 0.05). The findings of the present study suggest that the difference in semen quality in bulls with different RABL2B genotypes is generated via an alternative splicing mechanism caused by a functional SNP within the ESE motif.


2013 ◽  
Vol 82 (6) ◽  
pp. 430-432 ◽  
Author(s):  
X.-M. Nie ◽  
Y.-J. Zhu ◽  
Y. Zhang ◽  
W.-B. Qiao
Keyword(s):  

Author(s):  
Oshin Togla ◽  
S.M. Deb ◽  
Sagar Kadyan ◽  
P.B. Nandhini ◽  
Sushil Kumar ◽  
...  

Background: The experiment aimed to investigate polymorphisms in exon 2 of the PHKA2 gene and investigate the relationship between identified single nucleotide polymorphism and udder type traits in Sahiwal cows. Udder morphometry is being used as a forecaster of production performance in cows since older times. Finding the variants associated with these traits in largely variable region of PHKA2 gene can prove to be highly beneficial. Methods: DNA isolated from Sahiwal cows was analysed by DNA sequencing. Nine udder type and five teat types were measured for each animal according to procedure followed by International committee of animal recording (2012). Result: Three SNPs g.124497381C greater than T, X:124497248 G greater than A and X:124497189 C greater than T were identified. Recessive homozygotes were negligible as mutant allele exhibited very low ranging frequency (from 0.02 to 0.08) for the targeted loci. Identified point mutation g.124497381C greater than T was found to be significantly (p less than 0.05) associated with distance between teats and central ligament, SNP X: 124497248G greater than A with rear udder width, fore udder attachment, udder depth, udder length and teat length (p less than 0.05) and SNP X: 124497189 C greater than T with udder length and rear udder height (p less than 0.05). Interaction of identified SNPs and udder traits highlighted the gene’s potential as a candidate gene for selecting for conformation traits in Indian Sahiwal cattle.


2012 ◽  
Vol 45 (4) ◽  
pp. 496-499
Author(s):  
Fernanda Bernadelli Garcia ◽  
Simone Kashima ◽  
Evandra Strazza Rodrigues ◽  
Israel Tojal Silva ◽  
Tathiane Maistro Malta ◽  
...  

INTRODUCTION: The cytolysis mediated by granules is one of the most important effector functions of cytotoxic T lymphocytes and natural killer cells. Recently, three single nucleotide polymorphisms (SNPs) were identified at exons 2, 3, and 5 of the granzyme B gene, resulting in a haplotype in which three amino acids of mature protein Q48P88Y245 are changed to R48A88H245, which leads to loss of cytotoxic activity of the protein. In this study, we evaluated the frequency of these polymorphisms in Brazilian populations. METHODS: We evaluated the frequency of these polymorphisms in Brazilian ethnic groups (white, Afro-Brazilian, and Asian) by sequencing these regions. RESULTS: The allelic and genotypic frequencies of SNP 2364A/G at exon 2 in Afro-Brazilian individuals (42.3% and 17.3%) were significantly higher when compared with those in whites and Asians (p < 0.0001 and p = 0.0007, respectively). The polymorphisms 2933C/G and 4243C/T also were more frequent in Afro-Brazilians but without any significant difference regarding the other groups. The Afro-Brazilian group presented greater diversity of haplotypes, and the RAH haplotype seemed to be more frequent in this group (25%), followed by the whites (20.7%) and by the Asians (11.9%), similar to the frequency presented in the literature. CONCLUSIONS: There is a higher frequency of polymorphisms in Afro-Brazilians, and the RAH haplotype was more frequent in these individuals. We believe that further studies should aim to investigate the correlation of this haplotype with diseases related to immunity mediated by cytotoxic lymphocytes, and if this correlation is confirmed, novel treatment strategies might be elaborated.


Blood ◽  
1999 ◽  
Vol 93 (7) ◽  
pp. 2274-2281 ◽  
Author(s):  
H.R. Lijnen ◽  
K. Okada ◽  
O. Matsuo ◽  
D. Collen ◽  
M. Dewerchin

2-antiplasmin (2-AP) is the main physiologic plasmin inhibitor in mammalian plasma. Inactivation of the murine 2-AP gene was achieved by replacing, through homologous recombination in embryonic stem cells, a 7-kb genomic sequence encoding the entire murine protein (exon 2 through part of exon 10, including the stop codon) with theneomycin resistance expression cassette. Germline transmission of the mutated allele was confirmed by Southern blot analysis. Mendelian inheritance of the inactivated 2-AP allele was observed, and homozygous deficient (2-AP−/−) mice displayed normal fertility, viability, and development. Reverse transcription-polymerase chain reaction confirmed the absence of 2-AP mRNA in kidney and liver from 2-AP−/− mice, in contrast to wild-type (2-AP+/+) mice. Immunologic and functional 2-AP levels were undetectable in plasma of 2-AP−/− mice, and were about half of wild-type in heterozygous littermates (2-AP+/−). Other hemostasis parameters, including plasminogen activator inhibitor-1, plasminogen, fibrinogen, hemoglobin, hematocrit, and blood cell counts were comparable for 2-AP+/+, 2-AP+/−, and 2-AP−/− mice. After amputation of tail or toe tips, bleeding stopped spontaneously in 2-AP+/+, as well as in 2-AP+/− and 2-AP−/− mice. Spontaneous lysis after 4 hours of intravenously injected 125I-fibrin–labeled plasma clots was significantly higher in 2-AP−/− than in 2-AP+/+ mice when injecting clots prepared from 2-AP+/+ plasma (78% ± 5% v 46% ± 9%; mean ± SEM, n = 6 to 7; P = .02) or from 2-AP−/−plasma (81% ± 5% v 46% ± 5%; mean ± SEM, n = 5; P = .008). Four to 8 hours after endotoxin injection, fibrin deposition in the kidneys was significantly reduced in 2-AP−/− mice, as compared with 2-AP+/+ mice (P ≤ .005). Thus, 2-AP−/− mice develop and reproduce normally; they have an enhanced endogenous fibrinolytic capacity without overt bleeding.


2021 ◽  
Author(s):  
Isabelle C. Becker ◽  
Zoltan Nagy ◽  
Georgi Manukjan ◽  
Melanie Haffner-Luntzer ◽  
Maximilian Englert ◽  
...  

G6b-B is a megakaryocyte lineage-specific immunoreceptor tyrosine-based inhibition motif (ITIM)-containing receptor, essential for platelet homeostasis. Mice with a genomic deletion of the entire Mpig6b locus develop severe macrothrombocytopenia and myelofibrosis, which is reflected in humans with null-mutations in MPIG6B. The current model proposes that megakaryocytes lacking G6b-B develop normally, while proplatelet release is hampered, but the underlying molecular mechanism remains unclear. Here, we report on a spontaneous recessive single nucleotide mutation in C57BL/6 mice, localized within the intronic region of the Mpig6b locus that abolishes G6b-B expression and reproduces macrothrombocytopenia, myelofibrosis and osteosclerosis. As the mutation is based on a single nucleotide exchange, Mpig6bmut mice represent an ideal model to study the role of G6b-B. Megakaryocytes from these mice were smaller in size, displayed a less developed demarcation membrane system and reduced expression of receptors. RNA sequencing revealed a striking global reduction in the level of megakaryocyte specific transcripts, in conjunction with decreased protein levels of the transcription factor GATA-1, and impaired thrombopoietin signaling. The reduced number of mature MKs in the bone marrow was corroborated on a newly developed Mpig6b null mouse strain. Our findings highlight an unexpected essential role of G6b-B in the early differentiation within the megakaryocytic lineage.


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