422,477 research outputs found
A Novel Single Nucleotide Polymorphism in Exon 4 of Insulin-Like Growth Factor-1 Associated with Production Traits in Bali Cattle
Insulin-like growth factor-1 (IGF-1) is one of the gene candidates that can be used in selection strategy by using DNA markers (marker assisted selection). Gene candidate strategy is a molecular biology techniques to identify quantitative trait loci directly, with the assumption that genetic variation associated to quantitative trait variation. This study was designed to identify any new mutations in exon 4 that can cause the IGF-1 gene polymorphism and then affect the production traits on Bali cattle. Single nucleotide polymorphism (SNP) discovery was conducted by using the direct sequencing technique. Genetic variation of the genes candidate was identified by using PCR-RFLP technique. The results of this study indicate the presence of a new SNP in exon 4 of IGF-1 gene caused by the T/C transition, which can be identified using Rsa1 restriction enzyme. Genotypic polymorphism of IGF-1/Rsa1 has a significant influence on birth weight, weaning weight and average daily gain of Bali cattle. CC genotype had a birth weight rate, weaning weight and average daily gain of: 15.64±1.83; 83.15±9.00, and 0.439±0.07 respectively, higher than the TT and CT genotype. IGF-1/Rsa1 can be used as a genetic marker for selection of birth weight, weaning weight, and daily body weight gain
ZRT1 harbors an excess of nonsynonymous polymorphism and shows evidence of balancing selection in Saccharomyces cerevisiae
Estimates of the fraction of nucleotide substitutions driven by positive
selection vary widely across different species. Accounting for different
estimates of positive selection has been difficult, in part because selection
on polymorphism within a species is known to obscure a signal of positive
selection between species. While methods have been developed to control for the
confounding effects of negative selection against deleterious polymorphism, the
impact of balancing selection on estimates of positive selection has not been
assessed. In Saccharomyces cerevisiae, there is no signal of positive selection
within protein coding sequences as the ratio of nonsynonymous to synonymous
polymorphism is higher than that of divergence. To investigate the impact of
balancing selection on estimates of positive selection we examined five genes
with high rates of nonsynonymous polymorphism in S. cerevisiae relative to
divergence from S. paradoxus. One of the genes, a high affinity zinc
transporter ZRT1, shows an elevated rate of synonymous polymorphism indicative
of balancing selection. The high rate of synonymous polymorphism coincides with
nonsynonymous divergence between three haplotype groups, which we find to be
functionally indistinguishable. We conclude that balancing selection is not
likely to be a common cause of genes harboring a large excess of nonsynonymous
polymorphism in yeast
Polymorphisms of plasminogen activator inhibitor-1, angiotensin converting enzyme and coagulation factor XIII genes in patients with recurrent spontaneous abortion
We investigated polymorphisms of plasminogen activator inhibitor-1 (PAI-1), angiotensin converting enzyme (ACE ) and coagulation factor XIII (FXIII) genes and their association with recurrent spontaneous abortion (RSA) in Iranian patients and normal healthy controls. Ten (18.5%) patients were homozygote (4G/4G) for PAI-1 polymorphism, in contrast with two (2%) controls (p = 0.001). Patients with homozygote 4G mutation were significantly more prone to RSA in contrast to others (odds ratio: 11.0, 95% CI: 2.3-52.4). Nineteen (30.2%) patients and 25 (26.6%) controls were homozygote (DD) for ACE polymorphism. We observed only two patients and one control with homozygosity (34leu) for FXIII polymorphism. 4G/4G polymorphism for PAI-1 gene could be a thrombophilic mutation leading to abortion in Iranian population
Blood ties: ABO is a trans-species polymorphism in primates
The ABO histo-blood group, the critical determinant of transfusion
incompatibility, was the first genetic polymorphism discovered in humans.
Remarkably, ABO antigens are also polymorphic in many other primates, with the
same two amino acid changes responsible for A and B specificity in all species
sequenced to date. Whether this recurrence of A and B antigens is the result of
an ancient polymorphism maintained across species or due to numerous, more
recent instances of convergent evolution has been debated for decades, with a
current consensus in support of convergent evolution. We show instead that
genetic variation data in humans and gibbons as well as in Old World Monkeys
are inconsistent with a model of convergent evolution and support the
hypothesis of an ancient, multi-allelic polymorphism of which some alleles are
shared by descent among species. These results demonstrate that the ABO
polymorphism is a trans-species polymorphism among distantly related species
and has remained under balancing selection for tens of millions of years, to
date, the only such example in Hominoids and Old World Monkeys outside of the
Major Histocompatibility Complex.Comment: 45 pages, 4 Figures, 4 Supplementary Figures, 5 Supplementary Table
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