牛乳清蛋白遗传多态性研究

就牛乳清蛋白遗传多态性及其研究方法以及乳清蛋白多样性与乳品质之间的相关性作以阐述,旨在揭示当前该方向研究现状,并为今后研究提供参考。     

新疆克拉玛依地区人群18个STR位点的遗传多态性

实验目的:研究18个短串联重复序列(Short Tandem Repeat,STR)位点(D5S818、D21S11、D7S820、CSF1PO、D2S1338、D3S1358、vWA、D8S1179、D16S539、Penta E、TPOX、TH01、D19S433、D18S51、FGA、D6S1043、D13S317、D12S391)在新疆克拉玛依地区人群中的基因频率分布。实验方法:采用PCR扩增及毛细管电泳技术对332名个体的18个STR基因座进行分析。实验结果:共检出213种等位基因,基因频率分布在0.002~0.536之间。18个STR基因型分布均符合Hardy-Weinberg平衡(P0.05),杂合度均不低于0.589,个人识别能力均不小于0.795,多态信息含量均不小于0.56,非父排除概率均不小于0.278。结论:本文研究了新疆克拉玛依地区人群18个STR位点的遗传多态性,为人类群体遗传学及法医学后续研究提供详实可靠的基础数据。     

The Role of Natural Polymorphic Variants of DNA Polymerase β in DNA Repair

DNA polymerase β (Polβ) is considered the main repair DNA polymerase involved in the base excision repair (BER) pathway, which plays an important part in the repair of damaged DNA bases usually resulting from alkylation or oxidation. In general, BER involves consecutive actions of DNA glycosylases, AP endonucleases, DNA polymerases, and DNA ligases. It is known that protein–protein interactions of Polβ with enzymes from the BER pathway increase the efficiency of damaged base repair in DNA. However natural single-nucleotide polymorphisms can lead to a substitution of functionally significant amino acid residues and therefore affect the catalytic activity of the enzyme and the accuracy of Polβ action. Up-to-date databases contain information about more than 8000 SNPs in the gene of Polβ. This review summarizes data on the in silico prediction of the effects of Polβ SNPs on DNA repair efficacy; available data on cancers associated with SNPs of Polβ; and experimentally tested variants of Polβ. Analysis of the literature indicates that amino acid substitutions could be important for the maintenance of the native structure of Polβ and contacts with DNA; others affect the catalytic activity of the enzyme or play a part in the precise and correct attachment of the required nucleotide triphosphate. Moreover, the amino acid substitutions in Polβ can disturb interactions with enzymes involved in BER, while the enzymatic activity of the polymorphic variant may not differ significantly from that of the wild-type enzyme. Therefore, investigation regarding the effect of Polβ natural variants occurring in the human population on enzymatic activity and protein–protein interactions is an urgent scientific task.     

Utilizing Genomically Targeted Molecular Data to Improve Patient-Specific Outcomes in Autism Spectrum Disorder

Molecular biology combined with genomics can be a powerful tool for developing potential intervention strategies for improving outcomes in children with autism spectrum disorders (ASD). Monogenic etiologies rarely cause autism. Instead, ASD is more frequently due to many polygenic contributing factors interacting with each other, combined with the epigenetic effects of diet, lifestyle, and environment. One limitation of genomics has been identifying ways of responding to each identified gene variant to translate the information to something clinically useful. This paper will illustrate how understanding the function of a gene and the effects of a reported variant on a molecular level can be used to develop actionable and targeted potential interventions for a gene variant or combinations of variants. For illustrative purposes, this communication highlights a specific genomic variant, SHANK3. The steps involved in developing molecularly genomically targeted actionable interventions will be demonstrated. Cases will be shared to support the efficacy of this strategy and to show how clinicians utilized these targeted interventions to improve ASD-related symptoms significantly. The presented approach demonstrates the utility of genomics as a part of clinical decision-making.     

COVID-19 Pandemic: Escape of Pathogenic Variants and MHC Evolution

We propose a new hypothesis that explains the maintenance and evolution of MHC polymorphism. It is based on two phenomena: the constitution of the repertoire of naive T lymphocytes and the evolution of the pathogen and its impact on the immune memory of T lymphocytes. Concerning the latter, pathogen evolution will have a different impact on reinfection depending on the MHC allomorph. If a mutation occurs in a given region, in the case of MHC allotypes, which do not recognize the peptide in this region, the mutation will have no impact on the memory repertoire. In the case where the MHC allomorph binds to the ancestral peptides and not to the mutated peptide, that individual will have a higher chance of being reinfected. This difference in fitness will lead to a variation of the allele frequency in the next generation. Data from the SARS-CoV-2 pandemic already support a significant part of this hypothesis and following up on these data may enable it to be confirmed. This hypothesis could explain why some individuals after vaccination respond less well than others to variants and leads to predict the probability of reinfection after a first infection depending upon the variant and the HLA allomorph.     

滚环DNA扩增技术及其应用

滚环扩增技术是一种等温信号扩增方法,DNA可在很短时间内实现指数扩增,因此,可用于痕量分子的检测.目前,该技术既可以扩增环状DNA、RNA,也可以扩增线性DNA,甚至全基因组DNA.目前,该技术主要用于全基因组扩增、核酸测序、单核苷酸多态性以及DNA芯片、蛋白质芯片分析等广泛领域.     

Morphology study of progesterone polymorphs prepared by polymer‐induced heteronucleation (PIHn)

In this article, morphology of progesterone polymorphs prepared by polymer‐induced heteronucleation (PIHn) technique was studied. Hydroxypropyl methylcellulose(HPMC), such as dextran T‐500 and gelatin G‐9382, polyisoprene (PI), and acrylonitrile/butadiene copolymer (NBR) were used as substrates. The crystallizations were performed by solvent evaporation at room temperature from 0.5, 10, and 40 mg/ml solutions in chloroform and acetone. Progesterone polymorphs were identified by X‐ray diffraction. Differential scanning calorimetry and total attenuated reflectance infrared spectroscopy were used as complementary techniques in the identification. Depending on the polymeric matrix and the concentration used, form 1, form 2, or mixture of both polymorphs were obtained. Scanning electron microscopy pictures evidenced difference in morphology and in homogeneity of the two progesterone polymorphs. These polymorphs prepared by PIHn, did not present a distinctive morphology that allows identifying polymorph by its crystal habit. Hence, polymeric matrix induced the crystallization, affecting polymorphism and morphology. SCANNING 35:213‐221, 2013. © 2012 Wiley Periodicals, Inc.     

Short communication: characterization of a new genetic variant in the caprine kappa-casein gene

A new polymorphism has been identified in the goat kappa-casein gene by evaluating genomic DNA from the Montefalcone breed in Italy. The polymorphic site consists of a single nucleotide substitution A to G at position 242 of the exon 4 and produces an amino acid substitution Asp/Gly. A polymerase chain reaction-restriction fragment length polymorphism protocol for rapid genotyping of the variant has been developed, using the HaeIII enzyme. Animals from Italian, Spanish, and French breeds have been analyzed to investigate the occurrence of the allele in other populations. The allele appears to be exclusive to the Montefalcone breed.