Mining elite loci and candidate genes for root morphology-related traits at the seedling stage by genome-wide association studies in upland cotton(Gossypium hirsutum L.)

Root system architecture plays an essential role in water and nutrient acquisition in plants,and it is significantly involved in plant adaptations to various environmental stresses.In this study,a panel of 242 cotton accessions was collected to investigate six root morphological traits at the seedling stage,including main root length(MRL),root fresh weight(RFW),total root length(TRL),root surface area(RSA),root volume(RV),and root average diameter(AvgD).The correlation analysis of the six root morphological traits revealed strong positive correlations of TRL with RSA,as well as RV with RSA and AvgD,whereas a significant negative correlation was found between TRL and AvgD.Subsequently,a genome-wide association study(GWAS)was performed using the root phenotypic and genotypic data reported previously for the 242 accessions using 56,010 single nucleotide polymorphisms(SNPs)from the CottonSNP80K array.A total of 41 quantitative trait loci(QTLs)were identified,including nine for MRL,six for RFW,nine for TRL,12 for RSA,12 for RV and two for AvgD.Among them,eight QTLs were repeatedly detected in two or more traits.Integrating these results with a transcriptome analysis,we identified 17 candidate genes with high transcript values of transcripts per million(TPM)≥30 in the roots.Furthermore,we functionally verified the candidate gene GH_D05G2106,which encodes a WPP domain protein 2in root development.A virus-induced gene silencing(VIGS)assay showed that knocking down GH_D05G2106significantly inhibited root development in cotton,indicating its positive role in root system architecture formation.Collectively,these results provide a theoretical basis and candidate genes for future studies on cotton root developmental biology and root-related cotton breeding.

Genetic dissection and origin of pleiotropic loci underlying multilevel fiber quality traits in upland cotton(Gossypium hirsutum L.)

Cotton fiber quality is a persistent concern that determines planting benefits and the quality of finished textile products.However,the limitations of measurement instruments have hindered the accurate evaluation of some important fiber characteristics such as fiber maturity,fineness,and neps,which in turn has impeded the genetic improvement and industrial utilization of cotton fiber.Here,12 single fiber quality traits were measured using Advanced Fiber Information System(AFIS)equipment among 383 accessions of upland cotton(Gossypium hirsutum L.).In addition,eight conventional fiber quality traits were assessed by the High Volume Instrument(HVI)System.Genome-wide association study(GWAS),linkage disequilibrium(LD)block genotyping and functional identification were conducted sequentially to uncover the associated elite loci and candidate genes of fiber quality traits.As a result,the previously reported pleiotropic locus FL_D11 regulating fiber length-related traits was identified in this study.More importantly,three novel pleiotropic loci(FM_A03,FF_A05,and FN_A07)regulating fiber maturity,fineness and neps,respectively,were detected based on AFIS traits.Numerous highly promising candidate genes were screened out by integrating RNA-seq and qRT-PCR analyses,including the reported GhKRP6 for fiber length,the newly identified GhMAP8 for maturity and GhDFR for fineness.The origin and evolutionary analysis of pleiotropic loci indicated that the selection pressure on FL_D11,FM_A03 and FF_A05 increased as the breeding period approached the present and the origins of FM_A03 and FF_A05 were traced back to cotton landraces.These findings reveal the genetic basis underlying fiber quality and provide insight into the genetic improvement and textile utilization of fiber in G.hirsutum.

Evaluation of a Novel 32 X-STR Loci Multiplex System in the Forensic Application

The AGCU X Plus STR system is a newly developed multiplex PCR kit that detects 32 X-chromosomal STR loci simultaneously.These are DXS6807,DXS9895,linkage group 1(DXS10148,DXS10135,DXS8378),DXS9902,DXS6795,DXS6810,DXS10159,DXS10162,DXS10164,DXS7132,linkage group 2(DXS10079,DXS10074,DXS10075),DXS981,DXS6800,DXS6803,DXS6809,DXS6789,DXS7424,DXS101,DXS7133,GATA172D05,GATA165B12,linkage group 3(DXS10103,HPRTB,DXS10101),GATA31E08 and linkage group 4(DXS8377,DXS10134,DXS7423).A major advantage of this kit is that it takes into account linkage between loci,in addition to detecting more X-STR loci.In order to evaluate the forensic application of 32 X-STR fl uorescence amplifi cation system,PCR settings,sensitivity,species specifi city,stability,DNA mixtures,concordance,stutter,sizing precision,and population genetics investigation were evaluated according to the Scientific Working Group on DNA Analysis Methods(SWGDAM)developmental validation guidelines.The study showed that the genotyping results of each locus were signifi cantly accurate when the DNA template was at least 62.5 pg.Complete profi les were obtained for the 1∶1 and 1∶3 combinations.A total of 209 unrelated individuals from Southern Chinese Han community,consisting of 84 females and 125 males,were selected for population studies,and 285 allele profi les were detected from 32 X-STR loci.The polymorphism information content(PIC)ranged from 0.2721 in DXS6800,to 0.9105 in DXS10135,with an average of 0.6798.DXS10135(PIC=0.9105)was the most polymorphic locus,with discrimination power(DP)of 0.9164 and 0.9871 for the male and female.The cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) valu es were all greater than 0.999999999.There were 78 different DXS10103-HPRTB-DXS10101 haplotypes among the 125 males,and the haplotype diversity was 0.9810.There was no signifi cant difference in the cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) values whether considering linkage or not.In summary,the new X-STR multiplex typing system is effective and reliable,which can be useful in human genetic analysis and kinship testing as a potent complement to autosomal STR typing.

Identification of Quantitative Trait Loci for Anthesis-Silking Interval and Yield Components Under Drought Stress in Maize

A genetic linkage map with 89 SSR marker loci was constructed based on a maize (Zea mays L.) population consisting of 184 F-2 individuals from the cross, Huangzao 4 X Ye 107. The 184 F-3 families were evaluated in the field under well-watered and drought-stressed regimes in Shanxi Province of China. The objectives of the study were to identify genetic segments responsible for the expression of anthesis-silking interval (ASI), ear setting and grain yield, and to examine if the quantitative trait loci (QTLs) for ASI or yield components can be used in marker-assisted selection (MAS) to improve grain yield under drought conditions. Results showed that under well-watered and drought-stressed regimes, three and two QTLs involved in the expression of ASI were detected on chromosomes 1, 2 and 3, and 2 and 5, respectively. Under well-watered regime, two QTLs for ear setting were detected on chromosomes 3 and 6, explaining about 19.9% of the phenotypic variance, and displayed additive and partial dominant effects, respectively. Under drought-stressed condition, four QTLs for ear setting were detected on chromosomes 3, 7 and 10, which were responsible for interpreting 60.4% of the phenotypic variance, and showed dominant or partial dominant effects. Under well-watered condition, four QTLs controlling grain yield were identified on chromosomes 3, 6 and 7, while five QTLs were identified under drought stress on chromosomes 1, 2, 4 and 8. The gene action was of additive or partial dominant effects, and each QTL could explain 7.3% to 22.0% of the phenotypic variance, respectively. Under drought conditions, ASI and ear setting percentage were highly correlated with grain yield, which can be used as secondary traits for grain yield selection. Based on linked markers detected and gene action analyzed, an MAS strategy for yield improvement under drought condition could be established, which consists of QTLs contributing to decreased ASI and to increased ear setting and grain yield, respectively.

Detection of Quantitative Trait Loci Associated with Several Internal Organ Traits and Teat Number Trait in a Pig Population

Quantitative trait loci （QTL） were detected for 8 internal organ traits, 3 carcass length traits, and teat number trait in 214 pigs in a resource population that included 180 F2 individuals. A total of 39 microsatellite markers were examined on SSC4, SSC6, SSC7, SSC8, and SSC13. The genetic traits included heart weight （HW）, lung weight （LW）, liver and gallbladder weight （LGW）, spleen weight （SPW）, stomach weight （STW）, small intestine weight （S1W）, large intestine weight （LIW）, kidney weight （KW）, carcass length to the first cervical vertebra （CL1）, carcass length to the first thoracic vertebra （CL2）, rib numbers （RNS）, and teat numbers （TNS）. Results indicated that, 3 highly significant QTL （P≤0.01 at chromosome-wise level） for HW （at 30 cM on SSC6）, RNS （at 115 cM on SSC7）, TNS （at 110 cM on SSC7）, and 6 significant QTL （P≤0.05 at chromosome-wise level） for LW （at 119 cM on SSC13）, LGW （at 94 cM on SSC6）, SPW （at 106 cM on SSC8）, SIW （0 cM on SSC4）, LIW （170 cM on SSC 4）, and TNS （at 95 cM on SSC6） were detected. The phenotypic variances for which these QTL were accounted ranged from 0.04 % to 14.06 %. Most of these QTL had not been previously reported.

A Recursive Algorithm for Offspring's Genotype Frequency of Selfing Population on Multiple Alleles with Limited Loci

This paper studies the offspring＇s genotype frequency of the selfing population on multiple alleles with limited loci.A recursive algorithm is given for it.It is discovered that the genotype frequency of homozygous gene of limited loci increases by generations.Relative increment reduces by generations and the genotype frequency tends to a definite value finally.The genotype frequency of limited loci with hybrid gene tends to 0 finally.But it is possibility that the genotype frequency increases in previous generations then reduces later.It is found that the number of the hybrid gene are more,the speeds tending to 0 are quicker.

Cross-species amplification and characterization of microsatellite DNA loci from Gallus gallus in Bambusicola thoracica

The Chinese Bamboo Partridge(Bambusicola thoracica) is a gamebird endemic to China.Ten polymorphic microsatellite(simple sequence repeat) markers were obtained through cross-species amplification for this partridge from its relative species Gallus gallus.The number of alleles per locus varied from 4 to 13.The observed heterozygosity ranged from 0.1220 to 1.0000 and the expected heterozygosity from 0.1183 to 0.8898.Four microsatellite loci showed significant differences from the Hardy-Weinberg equilibrium.These polymorphic loci provide a valuable tool for the investigation of the phylogeography and conservation genetics of this partridge.

通过TELNET进行LOCIS信息查询

文章以检索美国国会图书馆LC目录为例介绍了在因特网上通过Telnet进行LOCIS信息查询的方法,同时对LOCIS中一些其它服务项目也做了介绍。

Detection of the Quantitative Trait Loci with AFLP and RFLP Markers for Phosphorus Uptake and Use Efficiency in Rice

To identify genetic factors underlying phosphorus (P) uptake and use efficiency under low_P stress in rice (Oryza sativa L.), 84 selected genotypes (recombinant inbred lines) and their parents (which differed in tolerance for low_P stress) “IR20” and IR55178_3B_9_3, were cultured in liquid medium supplemented with adequate and low P levels in a greenhouse. Plants were sampled after 6 weeks in culture for measurements of plant dry weight, P concentration, P uptake and P use efficiency under both P sufficient and stress conditions. A total of 179 molecular markers, including 26 RFLPs and 153 AFLPs, mapped on all 12 chromosomes of rice based on the 84 selected genotypes were used to detect the quantitative trait loci (QTLs) underlying tolerance for low_P stress. Three QTLs were detected on chromosomes 6, 7 and 12, respectively, for relative plant dry weight (RPDW) and relative P uptake (RPUP). One of the QTLs flanked by RG9 and RG241 on chromosome 12 had a major effect which explained about 50% of the variations in the two parameters across the population. The results coincided with the QTLs for low_P stress based on relative tillering ability from the same population from a cross between Nipponbare and Kasalath under soil condition. The identical major QTL for P uptake and plant growth under low_P stress in both liquid medium and soil strongly suggests that the ability of P uptake mainly controls rice tolerance for low_P stress.

血浆蛋白与骨质疏松症的关系及潜在治疗靶点:基于国际UK Biobank数据库信息

背景:骨质疏松症是全球范围内增加疾病负担和致残率的重要因素。血浆蛋白参与体内复杂的生物过程,在揭示疾病机制和发现潜在治疗靶点方面起着关键作用。尽管已有研究显示血浆蛋白与骨质疏松症之间存在关联,但这些关联的因果性质尚未得到充分阐明。因此,利用大规模的血浆蛋白数据探究与骨质疏松症相关的因果蛋白并识别潜在的药物靶点,对于骨质疏松症的防治至关重要。目的:运用两样本孟德尔随机化分析,以国际UK Biobank数据库为来源信息,评估血浆蛋白与骨质疏松症之间的因果关联。方法:从UK Biobank数据库获取1001种血浆蛋白相关的全基因组显著性水平(P<5×10-8)的蛋白质数量性状位点作为工具变量,并排除连锁不平衡。骨质疏松症的汇总数据来自FinnGen数据库,共涉及438872名欧洲血统个体。研究采用逆方差加权、MR-Egger回归、加权中位数等方法进行分析,并进行多项敏感性分析以确保结果的稳健性。进一步构建蛋白-蛋白互作网络,结合基因本体富集分析和京都基因与基因组百科全书通路分析,探索血浆蛋白的功能相关性及潜在作用机制。结果与结论:①孟德尔随机化逆方差加权法结果显示有50种血浆蛋白与骨质疏松症存在因果关系(P<0.05),包括染色体19开放阅读框12(chromosome 19 open reading frame 12,C19orf12;OR=0.610,95%CI:0.483-0.769,P=2.967×10-5)、表皮生长因子(OR=0.877,95%CI:0.770-0.999,P=0.049)等20种血浆蛋白可能与骨质疏松症的风险降低相关,有CCL18(OR=1.091,95%CI:1.037-1.147,P=0.001)、CD209(OR=1.036,95%CI:1.003-1.070,P=0.034)等30种血浆蛋白可能增加骨质疏松症的风险,经Bonferroni校正后,只有C19orf12与骨质疏松症存在显著的因果关联。②多项敏感性分析显示研究不存在多效性和异质性,说明结果具有稳健性。③通过构建蛋白-蛋白互作网络明确了表皮生长因子、CCL5、CXCL13、CXCL5、血管内皮生长因子C、CCL18、CCL17、TEK受体酪氨酸激酶、含免疫球蛋白样和表皮生长因子样结构域的酪氨酸激酶1(TIE1)和CCL23为核心蛋白。④基因本体富集分析和京都基因与基因组百科全书通路分析表明这些血浆蛋白在免疫系统中具有重要作用,通过参与信号传导、细胞迁移和趋化等过程影响骨质疏松症。⑤文章结果揭示了1001种血浆蛋白与骨质疏松症的潜在因果关联,这种基于大规模数据驱动的分析方法有助于在中国人群中识别新的生物标志物和药物靶点;其次,文章结果表明,免疫系统信号传导、细胞迁移和趋化等过程在骨质疏松症发病机制中发挥重要作用,这为特定遗传背景和环境因素下的骨质疏松症研究提供了新的方向;最后,研究中识别的核心蛋白(如表皮生长因子、CCL5及CXCL13等)有望成为新的生物标志物或药物靶点,为骨质疏松症的精准防治提供新的依据。

Analysis of SSR loci and development of SSR primers in Eucalyptus

In this study,28,691 genome sequences and16,566 expressed sequence tags(ESTs) of Eucalyptus were derived from the Gen Bank database.A total of 2292 SSR loci were sought out from 1785 effective sequences.Through analyses of SSR loci information,the SSR motif length was negatively correlated with the abundance of the SSRs.In the EST sequences of Eucalyptus,triplet repeat motifs were the most abundant,and dinucleotide repeats motifs had the highest frequencies.Subsequently,395 pairs of primers were designed based on the SSR loci.Using optimized SSR-PCR conditions,340 pairs of primers were successfully screened,with a success rate of 86.1%.By construction of a maximum likelihood phylogenetic tree of six eucalypt species,represented by five species of the genus Eucalyptus and one of the genus Corymbia,the genetic relationships of Eucalyptus urophylla and E.camaldulensis suggested by this tree was found to differ from that suggested by traditional morphological taxonomy.The results provide insights for evaluating geneticdiversity of Eucalyptus and analysis of Eucalyptus phylogenetics using SSR markers.

Mapping Quantitative Trait Loci Associated with Photoperiod Sensitivity in Maize(Zea mays L.)

Photoperiod sensitivity in maize plays an essential role in utilizing tropic and sub-tropic germplasm to temperate areas. This study aims to identify and map the QTLs responsible for the characteristics measuring photoperiod sensitivity, days from planting to silking （SD）, photoperiod response coefficient of silking （PRC）, and anthesis-silking interval （ASI）. Using the population derived from Zheng 58, photoperiod-insensitive parent, and Ya 8701, photoperiod-sensitive parent, a linkage map was constructed with 93 single sequence repeat （SSR） markers. Phenotyping of 296 F2-3 families of the population in replicated-field test was conducted in both long-day （Beijing, China） and short-day （Sichuan, China） conditions. Ten QTLs were identified to be associated with the SD and ASI on chromosomes 3, 4, 6, 8, and 10 in the longday conditions, and 11 QTLs were detected to be related to the SD and ASI on chromosomes 2, 3, 4, 5, 6, 8, and 10 in the short-day conditions, respectively. A QTL associated with the PRC as a major effect in the long-day conditions located in the same position as the QTL related to the SD and ASI in the map, and was on chromosome 10 linked with marker bnlg1655. Using these QTLs in the marker-assisted selection, the photoperiod sensibility could be reduced by selection of the alleles responsible for the SD, PRC, and ASI in breeding programs.

Detection of Drought-Related Loci in Rice at Reproductive Stage Using Selected Introgressed Lines

The present study was carried out to illustrate high-efficient detection of quantitative trait loci （QTLs） with selected introgression lines （ILs） and the existence of ＇hidden genes＇ conferring drought tolerance （DT）. 52 selected DT ILs, derived from BC2Fz population developed by crossing and backcrossing the susceptible recurrent parent （RP） IR64 with the susceptible donor Khazar were planted under irrigation and drought condition. Four important agronomic traits, e.g., grain yield （GY）, heading date （HD）, panicle numbers per plant （PN）, and plant height （PH） were evaluated and 83 SSR polymorphic molecular markers were used for genotypic analysis. Chi-square test based on genetic hitch-hiking and one-way analysis of variances （ANOVA） were used to detect drought-related loci. Nine and 36 loci were detected by chi-square test and one-way ANOVA, respectively. Five common loci were observed by comparing the results of the two methods, among which two QTLs linked with RM7, and RM241 were detected under irrigation condition, both of the favorable alleles were from RP and explained 13% phenotypic variation （PV） for GY and 28% PV for PH, respectively. The other three QTLs linked with RM 163, RM 18, and RM270 were detected under drought condition, the favorable alleles were all from the donor and explained 10, 24, and 19% PV for HD, PH, and PH, respectively. Five common loci were observed by comparing the results of chi-square test and one-way ANOVA including two QTLs （one for GY and one for PH） under irrigation condition and three QTLs （one for HD and two for PH） under drought condition. By combining phenotypic and genotypic analysis, drought escape could be inferred as the main mechanism for drought tolerance in the present study. The results in present study suggested that the selected ILs population analyzed by chi-square test and one-way ANOVA was quite effective for DT QTL detection with low inputs and could also produce useful materials for breeding with wide genetic diversity for drought tolerance.

Computational analysis of genetic loci required for synapse structure and function and their corresponding microRNAs in C. elegans

Objective To elucidate the important functions of microRNAs （miRNAs） in regulating synaptic assembly and function, we performed a computational analysis for the genetic loci required for the synaptic structure and function and their corresponding miRNAs in C. elegans. Methods Total 198 genetic loci required for the synaptic structure and function were selected. Sequence alignment was combined with E value evaluation to investigate and identify the possible corresponding miRNAs. Results Total 163 genes among the 198 genetic loci selected have their possibly corresponding regulatory miRNA （s）, which covered most of the important genetic loci required for the synaptic structure and function. Moreover, only 22 genes among the analyzed 38 genetic loci encoding synaptic proteins have more possibility to under the control of non-coding RNA genes. In addition, the distribution of miRNAs along the 3＇ untranslated region （UTR） of these 22 genes exhibits different patterns. Condusion Here we provide the computational screen and analysis results for the genetic loci required for synaptic structure and function and their possible corresponding miRNAs. These data will be useful for the further attempt to systematically determine the roles of miRNAs in synaptic assembly and function regulation in worms.

Effects of SNPs at Newly Identified Lipids Loci on Blood Lipid Levels and Risk of Coronary Heart Disease in Chinese Han Population:A Case Control Study

Associations between ＂lipid-related＂ candidate genes,blood lipid concentrations and coronary artery disease（CHD） risk are not clear.We aimed to investigate the effect of three newly identified lipids loci from genome-wide association studies on CHD and blood lipid levels in Chinese Han population.The genotypes of SNPs at three newly identified lipid loci and blood lipids concentrations were examined in 1360 CHD patients and 1360 age-and sex-frequency matched controls from an unrelated Chinese Han population.Allele T of rs16996148 occurred less frequently in CHD patients with the odds ratio（OR） being 0.64（95% CI 0.50 to 0.81）,after adjusting for conventional risk factors and was associated with a 33% decreased CHD risk（P0.01） comparing with the major allele G.Individuals with GT genotype had the lowest CHD risk.No associations were found between the polymorphisms of other two loci with CHD risk and all three SNPs had no effect on lipid profile in this population.SNP rs16996148 on chromosome 19p13 is significantly associated with lower risk for CHD in Chinese Han population.However,it remains unresolved why these lipid-related loci had significantly less effects than the correspondingly expected effects on blood lipids levels in this population.

Evaluation of Four Candidate VNTR Loci for Genotyping 225 Chinese Clinical Mycobacterium Tuberculosis Complex Strains

Objective To evaluate four candidate variable number tandem repeat （VNTR） loci for genotyping Mycobacterium tuberculosis complex strains. Methods Genomic sequences for two M. tuberculosis strains （CCDC5079 and CCDC5180） were generated, and using published sequence data, four candidate VNTR loci were identified. The VNTRs were used to genotype 225 Chinese clinical M. tuberculosis complex strains. The discriminatory power of the VNTRs was evaluated using BioNumerics 5.0 software. Results The Hunter-Gaston Index （HGI） for BJ1, BJ2, BJ3, and BJ4 loci was 0.634, 0.917, 0.697, and 0.910, respectively. Combining all four loci gave an HGI value of 0.995, thus confirming that the genotyping had good discriminatory power. The HGI values for BJ1, BJ2, BJ3, and BJ4, obtained from Beijing family strain genotyping, were 0.447, 0.878, 0.315, and 0.850, respectively. Combining all four loci produced an HGI value of 0.988 for genotyping the Beijing family strains. We observed unique patterns for M. boris and M. africanum strains from the four loci. Conclusion We have shown that the four VNTR loci can be successfully used for genotyping M. tuberculosis complex strains. Notably, these new loci may provide additional information about Chinese M. tuberculosis isolates than that currently afforded by established VNTR loci typing.

Heterotic loci identified for plant height and ear height using two CSSLs test populations in maize

Heterosis is an important biological phenomenon, and it has been used to increase grain yield, quality and resistance to abiotic and biotic stresses in many crops. However, the genetic mechanism of heterosis remains unclear up to now. In this study, a set of 184 chromosome segment substitution lines （CSSLs） population, which derived from two inbred lines Ix9801 （the recurrent parent） and Chang 72 （the donor parent）, were used as basal material to construct two test populations with the inbred lines Zheng 58 and Xun 9058. The two test populations were evaluated in two locations over two years, and the heterotic loci for plant height and ear height were identified by comparing the performance of each test hybrid with the corresponding CK at P〈0.05 significant level using one-way ANOVA analysis and Duncan＇s multiple comparisons. There were 24 and 29 different heterotic loci （HL） identified for plant height and ear height in the two populations at two locations over two years. Three HL （hlPH4a, hlPH7c, hlPHlb） for plant height and three （hlEHld, hlEH6b, hlEHlb） for ear height were identified in the CSSLs×Zheng 58 and CSSLs×Xun 9058 populations as contributing highly to heterosis performance of plant height and ear height across four environments. Among the 29 HL identified for ear height, 12 HL （41.4%） shared the same chromosomal region associated with the HL （50.0%） identified for plant height in the same test population and environment.

Genius Loci of Urban Public Spaces: A Case Study of Daihu Lake Landscape Planning in New Shouzhan District, Changle City, Fujian Province

Connotations of genius loci of urban public spaces were explored, geographical position and composition of Daihu landscape design in New Shouzhan District, Changle City, Fujian Province was introduced. Design concepts, layouts and patterns were summarized by combining with geographical and cultural conditions of the study area. Functional zoning of Daihu landscape design was analyzed, human-centered site planning stressed to realize functions of new urban public spaces, regression of cultural and humanistic properties of these spaces, so as to provide diverse options for the future construction of urban public spaces.

Mapping of Quantitative Trait Loci Affecting Eggshell Quality in an F_2 Population Derived from Strong and Weak Eggshell Lines of the White Leghorn Chicken Breed

Broken and cracked eggshells cause major economic losses to the egg production industry. An F2 population of 262 hens obtained by crossing a strong egg shell line with a weak egg shell line of the White Leghorn breed was used for detecting the quantitative trait loci （QTL） affecting eggshell quality. The 2 lines were developed from the same founder population by two-way selection for egg shell strength with nondestructive deformation. Of the 1 014 microsatellite markers tested, 35 were mapped on 10 autosomal linkage groups. There was no informative marker on chromosome Z. The QTLs associated with 7 traits, i.e., body weight, short length of egg, long length of egg, eggshell strength, eggshell thickness （EST）, eggshell weight （ESW）, and egg weight （EW）, were identified. Highly significant （P〈0.01） QTLs associated with EST and ESW and a significant （P〈 0.05） QTL associated with EW were mapped to a region flanking ABR0545 and ABR0362 on chromosome 9. These QTLs are good candidates to be employed in the development of strategies for reducing the number of broken and cracked eggs in commercial layer houses by employing marker assisted selection.

Isolation and Characterization of 17 Microsatellite DNA Loci for Odorrana margaretae(Anura: Ranidae)

We isolated and characterized 17 microsatellite DNA loci for the odorous frog Odorrana margaretae from its transcriptome sequence data. These loci were screened with 24 individuals from Mt. Emei. All loci were polymorphic, with the number of alleles ranging from 2 to 8. The observed and expected heterozygosity, polymorphism information content, ranged from 0.04 to 1, 0.04 to 0.81, and 0.040 to 0.763, respectively. All loci were in linkage equilibrium and six loci were significantly deviated from Hardy-Weinberg equilibrium after sequential Bonferroni corrections. Cross- species amplification test was conducted for ten odorous frog species, and 12 loci were amplifiable in most species. With the high cross-species amplification rates, thesc markers will provide useful molecular tools for conservation genetic and phylogeographic studies on the genus Odorrana and Bamburana.