Genetic Diversity and Population Structure in Landraces and Improved Rice Varieties from India

A set of 50 rice genotypes comprising landraces, local selections, and improved varieties were characterized using simple sequence repeat（SSR） and inter simple sequence repeat（ISSR） markers to study genetic diversity and population structure. Following unweighted pair group method with arithmetic mean based clustering using binary data of polymorphic markers, the genotypes were grouped into 5 clusters and 11 sub-clusters, whereas population structure analysis separated 50 rice genotypes into 5 sub-populations. Grouping of rice genotypes showed better resemblance with the pedigree information of the genotypes. Both genetic diversity and population structure analysis separated majority of the improved varieties from landraces and local selections. Some of the SSR markers amplified unique alleles which were specific to a particular genotype and could distinguish them from the rest. The results indicate that these rice genotypes exhibit a higher genetic diversity and can be very useful in rice improvement program.

Design Optimization of CFRP Stacking Sequence Using a Multi-Island Genetic Algorithms Under Low-velocity Impact Loads

A method to improve the low-velocity impact performance of composite laminate is proposed, and a multi-island genetic algorithm is used for the optimization of composite laminate stacking sequence under low-velocity impact loads based on a 2D dynamic impact finite element analysis. Low-velocity impact tests and compression-after impact（CAI） tests have been conducted to verify the effectiveness of optimization method. Experimental results show that the impact damage areas of the optimized laminate have been reduced by 42.1% compared to the baseline specimen, and the residual compression strength has been increased by 10.79%, from baseline specimen 156.97 MPa to optimized 173.91 MPa. The tests result shows that optimization method can effectively enhance the impact performances of the laminate.

Informative ISSR Markers Help Identify Genetically Distinct Accessions of Oryza rufipogon in Yield Improvement

Inter simple sequence repeat（ISSR） polymorphism was used to determine genetic diversity and phylogenetic relationships in 90 genotypes of wild and cultivated species of Oryza from different geographical regions of the world. In all the 17 primers used in ISSR-PCR, a total of 11 464 bands were amplified at 253 band positions/loci. The primer UBC-809 amplified the maximum bands（1 059） at 21 band positions. UBC-810 and UBC-835 amplified the minimum of 391 bands each at 7 and 14 band positions, respectively. The mean polymorphism information content ranged from 0.44 to 0.84 and resolving power ranged from 8.69 to 23.53. Un-weighted pair group method with arithmetic mean dendrogram and population structure based on the 17 primers separated all genotypes into 4 major clusters with a genetic similarity of 53%–100%. The first two clusters consisted of 30 O. rufipogon accessions each. In the third cluster, O. nivara and O. longistaminata grouped as one sub-cluster and all other O. nivara accessions and cultivars grouped as another sub-cluster. The fourth cluster had only five O. rufipogon accessions which can be a source of new genes. Four sub-populations were identified within O. rufipogon and two sub-populations within O. nivara at K = 7. A subset of six primers with high resolving power values were the most informative and grouped all genotypes almost similarly as the 17 primers did. Use of these six highly informative primers in ISSR-PCR is a cost effective and robust method for assessing genetic diversity in large germplasm collections of wild rice species.

The Genetic Structure and Diversity of Repomucenus curvicornis Inhabiting Liaoning Coast Based on Mitochondrial COⅠ Gene and Control Region

[Object] This study was conducted to explore the genetic diversity and structure of the wild Repomucenus curvicornis inhabiting Liaoning Coast, China. [Method] The mitochondrial COⅠ gene and control region（CR） were PCR amplified from the wild R. curvicornis populations from the Liaodong Bay（n=22） and the northern Yellow Sea（n=18）, sequenced and analyzed for genetic diversity. [Result] The contents of A, T, C and G of 624 bp COⅠ gene were 24.09%, 31.04%, 25.28%, and 19.59%, and those of 460 bp CR fragment were 32.96%, 32.80%, 14.86% and 19.38%, respectively. The total number of variable sites, average number of nucleotide differences（ k）, haplotype diversity（H） and nucleotide diversity（π） based on COⅠ gene were 38, 4.67,（0.96±0.02） and（0.007 5±0.004 2）, and those based on CR fragment were 26, 3.35,（0.97 ±0.02） and（0.007 3±0.004 3）, respectively. Based on mitochondrial COⅠ gene and CR, the genetic diversity of Liaodong Bay population was lower than that of the northern Yellow Sea population. The AMOVA analysis based on CR fragments revealed almost significant genetic divergence between the Liaodong Bay and the northern Yellow Sea populations, while there was no significant genetic divergence based on COⅠ gene. The results showed that CR and COⅠ gene are effective molecular markers for detecting the genetic diversity of R. curvicornis population, while CR is more reliable than COⅠ gene in detecting the genetic structure. [Conclusion] CR is an appropriate marker for genetic analysis of marine fish population.

A multicenter prospective study of next-generation sequencing-based newborn screening for monogenic genetic diseases in China

Background Newborn screening(NBS)is an important and successful public health program that helps improve the long-term clinical outcomes of newborns by providing early diagnosis and treatment of certain inborn diseases.The develop-ment of next-generation sequencing(NGS)technology provides new opportunities to expand current newborn screening methodologies.Methods We designed a a newborn genetic screening(NBGS)panel targeting 135 genes associated with 75 inborn disorders by multiplex PCR combined with NGS.With this panel,a large-scale,multicenter,prospective multidisease analysis was conducted on dried blood spot(DBS)profiles from 21,442 neonates nationwide.Results We presented the positive detection rate and carrier frequency of diseases and related variants in different regions;and 168(0.78%)positive cases were detected.Glucose-6-Phosphate Dehydrogenase deficiency(G6PDD)and phenylketonuria(PKU)had higher prevalence rates,which were significantly different in different regions.The positive detection of G6PD variants was quite common in south China,whereas PAH variants were most commonly identified in north China.In addi-tion,NBGS identified 3 cases with DUOX2 variants and one with SLC25A13 variants,which were normal in conventional NBS,but were confirmed later as abnormal in repeated biochemical testing after recall.Eighty percent of high-frequency gene carriers and 60%of high-frequency variant carriers had obvious regional differences.On the premise that there was no significant difference in birth weight and gestational age,the biochemical indicators of SLC22A5 c.1400C>G and ACADSB c.1165A>G carriers were significantly different from those of non-carriers.Conclusions We demonstrated that NBGS is an effective strategy to identify neonates affected with treatable diseases as a supplement to current NBS methods.Our data also showed that the prevalence of diseases has significant regional charac-teristics,which provides a theoretical basis for screening diseases in different regions.

Gene targeted and immune therapies for nodal and gastrointestinal follicular lymphomas

Follicular lymphoma(FL)is the most common indolent B-cell lymphoma(BCL)globally.Recently,its incidence has increased in Europe,the United States,and Asia,with the number of gastrointestinal FL cases expected to increase.Genetic abnormalities related to t(14;18)translocation,BCL2 overexpression,NF-κB pathway-related factors,histone acetylases,and histone methyltransferases cause FL and enhance its proliferation.Meanwhile,microRNAs are commonly used in diagnosing FL and predicting patient prognosis.Many clinical trials on novel therapeutics targeting these genetic abnormalities and immunomodulatory mechanisms have been conducted,resulting in a marked improvement in therapeutic outcomes for FL.Although developing these innovative therapeutic agents targeting specific genetic mutations and immune pathways has provided hope for curative options,FL treatment has become more complex,requiring combinatorial therapeutic regimens.However,optimal treatment combinations have not yet been achieved,highlighting the importance of a complete understanding regarding the pathogenesis of gastrointestinal FL.Accordingly,this article reviews key research on the molecular pathogenesis of nodal FL and novel therapies targeting the causative genetic mutations.Moreover,the results of clinical trials are summarized,with a particular focus on treating nodal and gastrointestinal FLs.

Identification of the Genetic Cause for Childhood Disintegrative Disorder by Whole-Exome Sequencing

Dear Editor,Childhood Disintegrative Disorder（CDD）,also known as Heller’s syndrome and disintegrative psychosis,is a rare progressive neurological disorder,characterized by a late onset（[2 years of age）and regression of language,social

Genetic studies of schizophrenia:an update

Schizophrenia（SCZ） is a complex and heterogeneous mental disorder that affects about 1% of global population. In recent years,considerable progress has been made in genetic studies of SCZ. A number of common variants with small effects and rare variants with relatively larger effects have been identifi ed. These variants include risk loci identifi ed by genome-wide association studies,rare copy-number variants identifi ed by comparative genomic analyses,and de novo mutations identified by high-throughput DNA sequencing. Collectively,they contribute to the heterogeneity of the disease. In this review,we update recent discoveries in the fi eld of SCZ genetics,and outline the perspectives of future directions.

Case report of neurofibromatosis type 1 combined with primary ciliary dyskinesia

Neurofibromatosis(NF)is a genetic disease in which the lungs are rarely involved.However,in NF cases with lung involvement,chest computed tomography may show bilateral basal reticulations,apical bullae,and cysts without bronchiectasis.Herein,we report a patient diagnosed with NF on the basis of the results of genetic testing who presented with early-onset wet cough and bronchiectasis.Considering the differential diagnosis of bronchiectasis combined with his early-onset wet cough,sinusitis,and sperm quality decline,we considered the possibility of primary ciliary dyskinesia(PCD).Further electron microscopy analysis of cilia and identification of homozygous mutations in the RSPH4A gene confirmed the diagnosis of PCD.Therefore,for patients with NF,when an image change exists in the lungs that does not correspond to NF,the possibility of other diagnoses,including PCD,must be considered.