The N-terminal His-tag affects the triglyceride lipase activity of hormone-sensitive lipase in testis.

The sterility of hormone-sensitive lipase (HSL) knockout mice clearly shows the link between lipid metabolism and spermatogenesis. However, which substrate or product of this multifunctional lipase affects spermatogenesis is unclear. We found that an HSL protein with a His-tag at the N-terminus preserved the normal hydrolase activity of cholesteryl ester (CE) but the triglyceride lipase (TG) activity significantly decreased in vitro. Therefore, mice with this functionally incomplete HSL (His-HSL) were produced on a background of HSL deficiency (HSL-/- h). As a result, HSL-/- h testis has an 8.65-fold higher CE activity than wild-type testis but a twofold higher TG activity than wild-type testis. To compare His-HSL and wild-type HSL in vitro and in vivo, we confirmed that the His-tag significantly suppressed HSL TG activity. From our results, we believe that TG activity was affected by the His-tag insertion, but CE activity was not influenced. Furthermore, the His-tag protected HSL from binding to the inhibitor BAY. From our study, TG activity and BAY binding sites were affected by N-terminal His-tag insertion.

Association Between Nitrite and Nitrate Intake and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND Studies have shown inconsistent associations of nitrite and nitrate intake with the risk of gastric cancer or its associated mortality. We performed a meta-analysis of observational studies to evaluate the correlation of nitrite and nitrate intake with the risk of gastric cancer. MATERIAL AND METHODS We searched for studies reporting effect estimates and 95% confidence intervals (CIs) of gastric cancer in PubMed, EMBASE, and the Cochrane Library through November 2018. The summary results of the included studies were pooled using a random-effects model. RESULTS Eighteen case-control and 6 prospective cohort studies recruiting 800 321 participants were included in this study. The summary results indicated that the highest (odds ratio [OR], 1.27; 95%CI, 1.03-1.55; P=0.022) or moderate (OR: 1.12; 95%CI, 1.01-1.26; P=0.037) nitrite intake were associated with a higher risk of gastric cancer. However, we noted that high (OR, 0.81; 95%CI, 0.68-0.97; P=0.021) or moderate (OR, 0.86; 95%CI, 0.75-0.99; P=0.036) nitrate intakes were associated with a reduced risk of gastric cancer. These associations differed when stratified by publication year, study design, country, the percentage of male participants, assessment of exposure, adjusted model, and study quality. CONCLUSIONS High or moderate nitrite intake was associated with higher risk of gastric cancer, whereas high or moderate nitrate intake was correlated with lower risk of gastric cancer.

[The development of genetics teaching in China in the last four decades and its future prospect].

Chinese genetics educators have carried out a comprehensive and systematic exploration and reform since 1978. With the guidance and help of the Genetics Society of China, they have made significant strides in the fields of genetics teaching system, publication of genetics textbooks, content of genetics teaching, workshop on genetics teaching, experimental teaching, application of advanced techniques, etc. These efforts have made remarkable achievements and promoted the vitality of genetics. The comprehensive development of education and teaching has trained a large number of excellent genetic talents for the development of China's economy and society. Here, we sum up the overall achievements of the teaching reform and propose some suggestions on the future development of genetics teaching in China, hoping that the quality of genetics teaching in China will take a new step in the new era.

Negative regulation of RIG-I-mediated innate antiviral signaling by SEC14L1.

Retinoic acid-inducible gene I (RIG-I) is a key sensor for recognizing nucleic acids derived from RNA viruses and triggers beta interferon (IFN-ß) production. Because of its important role in antiviral innate immunity, the activity of RIG-I must be tightly controlled. Here, we used yeast two-hybrid screening to identify a SEC14 family member, SEC14L1, as a RIG-I-associated negative regulator. Transfected SEC14L1 interacted with RIG-I, and endogenous SEC14L1 associated with RIG-I in a viral infection-inducible manner. Overexpression of SEC14L1 inhibited transcriptional activity of the IFN-ß promoter induced by RIG-I but not TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3). Knockdown of endogenous SEC14L1 in both HEK293T cells and HT1080 cells potentiated RIG-I and Sendai virus-triggered IFN-ß production as well as attenuated the replication of Newcastle disease virus. SEC14L1 interacted with the N-terminal domain of RIG-I (RIG-I caspase activation and recruitment domain [RIG-I-CARD]) and competed with VISA/MAVS/IPS-1/Cardif for RIG-I-CARD binding. Domain mapping further indicated that the PRELI-MSF1 and CRAL-TRIO domains but not the GOLD domain of SEC14L1 are required for interaction and inhibitory function. These findings suggest that SEC14L1 functions as a novel negative regulator of RIG-I-mediated antiviral signaling by preventing RIG-I interaction with the downstream effector.

The distribution of genetic diversity of KIR genes in the Chinese Mongolian population.

Killer cell immunoglobulin-like receptors (KIRs) are expressed on natural killer cells and as such regulate their response against infection and malignancy. KIR genes are variable in gene content and type, which results in different KIR haplotypes, and can be used to discriminate individuals and populations from different regions or ethnic groups. In the present study, we represent the first report on the KIR gene frequency and content diversities of 14 KIR genes (KIR2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1) and 2 pseudogenes (KIR3DP1 and 2DP1) in the Chinese Mongolian population. The 16 detected KIR genes were all observed. All the individuals were typed positive for the four framework genes KIR3DL3, 3DL2, 2DL4 and the pseudogene KIR3DP1, as well as for the pseudogene KIR2DP1. The observed carrier gene frequencies (OF) of the other KIR genes ranged from 16% at the KIR2DL2 locus to 93% at the KIR3DL1 locus. Over all, 48 different gene profiles were found in the study population and the most commonly observed KIR gene profile with a frequency of 14% consisted of KIR2DL4, 3DL2, 3DL3, 2DP1, 3DP1, 2DL1, 2DL3 and 3DL1 which belongs to the AA genotype. Principal component analysis (PCA) and the dendrogram illustrated the genetic distances between our study population and previously published populations from other ethnic groups or regions. The results of the present study show that the KIR gene family is highly polymorphic and can be a valuable tool for enriching the Chinese ethnical gene information resources, for anthropological studies, as well as for KIR gene related disease research.

[Application of case-based method in genetics and eugenics teaching].

Genetics and Eugenics is a cross-discipline between genetics and eugenics. It is a common curriculum in many Chinese universities. In order to increase the learning interest, we introduced case teaching method and got a better teaching effect. Based on our teaching practices, we summarized some experiences about this subject. In this article, the main problem of case-based method applied in Genetics and Eugenics teaching was discussed.

Genetic variation of new 21 autosomal short tandem repeat loci in a Chinese Salar ethnic group.

In the present study, we reported the allele frequencies for new 21 autosomal short tandem repeat (STR) loci, including D6S474, D12ATA63, D22S1045, D10S1248, D1S1677, D11S4463, D1S1627, D3S4529, D2S441, D6S1017, D4S2408, D19S433, D17S1301, D1GATA113, D18S853, D20S482, D14S1434, D9S1122, D2S1776, D10S1435 and D5S2500 loci. Forensic statistical parameters were estimated from a sample set of 120 unrelated healthy individuals from the Salar ethnic group in Xunhua Salar Autonomous County of Qinghai province, China. A total of 151 alleles were observed at 21 STR loci in the population, and their allele frequencies were in the range of 0.004-0.554. All STR loci showed a high degree of genetic polymorphisms, and the combined probability of exclusion, combined power of discrimination and combined probability of matching for all 21 STR loci were 0.9999993134, 0.99999999999999999991739 and 8.2607 × 10(-20), respectively. For all the 21 STR loci in the Salar ethnic group, the observed genotypic data showed no significant deviation from those expected under the Hardy-Weinberg equilibrium. The allele frequency distributions for the 21 autosomal STR loci were compared between the Salar group and its neighboring populations and significant differences were detected among these populations at D1S1677, D2S441, D3S4529, D4S2408, D6S1017, D11S4463, D12ATA63, D14S14343, D18S853, D19S433 and D22S1045 loci.

[The exploration and implication of the concept map in genetics teaching.].

The concept map is a kind of chart used to represent and reveal the relationship among the knowledge structures. In genetics teaching, selectively using the concept map can help teachers to organize and review the course contents and also to detect students' academic achievement. It can also promote students' cognitive level, assist students to establish a system integrated knowledge hierarchy, etc. The exploration and implication of concept map in genetics teaching are reviewed in this paper.

[Exploration and practice of genetics teaching assisted by network technology platform].

More teaching techniques have been brought out gradually along with the development of new technologies. On the basis of those traditional teaching methods, a new platform has been set up by the network technology for teaching process. In genetics teaching, it is possible to use the network platform to guide student studying, promote student's learning interest and study independently by themselves. It has been proved, after exploring and applying for many years, that network teaching is one of the most useful methods and has inimitable advantage comparing to the traditional ones in genetics teaching. The establishment of network teaching platform, the advantage and deficiency and relevant strategies were intro-duced in this paper.

[Peptide Nucleic Acids (PNA)--the explorer of gene mystery].

Peptide Nucleic Acids(PNA) are DNA analogues in which the naturally occurring nucleobases are attached via methylene carbonyl linkages to an achiral pseudopeptide backbone of N-(2-aminoethyl) glycine units. PNA can bind to both DNA and RNA targets in a sequence-specific manner. PNA provides a powerful tool to study the mechanism for gene replication and transcription as well as an innovative strategy to regulate target gene expression. Advances as a probe in molecular biotechnology have greatly improved the sensitivity and the efficiency in genetic investigations and diagnosis. Peptide Nucleic Acid (PNA) which recognizes and binds to a complementary nucleic acid sequence presents unique physicochemical properties and has been incorporated into an expanding set of biological investigations. Accordingly, PNA is becoming the explorer of gene mystery.

[On the research of histone methylation].

The types of histone methyltransferases, the relationship between methylation of Lysine 9 of H3 and the formation of heterochromatin, gene regulation in euchromatin, and that with DNA methylation, were mainly introduced. The interrelation between histone methylation and histone acetylation/phosphorylation was summarized. It is showed that histone methylation plays a very important role in maintaining the balance state of cell. The future research tendency of histone methylation was fantastic.

[The role of the carboxy-terminal domain of the RNA polymerase II on coupling mRNA transcription with processing].

The carboxy-terminal domain of the largest subunit of the RNA polymerase II (CTD) is comprised of multiple repeats of a conserved heptapeptide with the consensus sequence-Tyr-Ser-Pro-Thr-Ser-Pro-Ser-. In the past decade,much attention has been payed to this specific structure. Many experiments showed that the CTD played a pivotal role in the coupling mechanism that links mRNA transcription with processing by associating with the transcriptional and processing factors. The recent advance of the structure and functions is summarized in this paper.