多巴胺D4受体基因与注意缺损多动障碍

为探讨注意缺损多动障碍(ADHD)与多巴胺D4受体基因(dopamineD4receptorgene,DRD4)间的关系,采用Amp-FLP的方法检测了上海地区汉族人群中68例ADHD患者及其父母DRD4的多态性,数据采用基于单体型的单体型相对风险(HHRR)及传递不平衡检验(TDT)进行遗传关联分析.结果表明HHRR分析和复等位基因的TDT检验,均未显示出与ADHD的遗传关联性(P＞0.05).提示上海地区人群中DRD4基因与ADHD无显著性关联。 Abstract:The present study was designed to investigate the association between attention-deficit hyperactivity disorder (ADHD) and the dopamine D4 receptor gene (DRD4).Amp-FLP was used to test the polymorphisms of DRD4 in 68 ADHD children and their parents from Shanghai.The haplotype-based haplotype relative risk (HHRR) and transmission disequilibrium test (TDT) methods were used to analyze the association between DRD4 and ADHD.In our samples we found no significant association between DRD4 and ADHD (P>0.05).Our results do not support that ADHD is associated with DRD4 in population in Shanghai.     

注意缺损多动障碍的X染色体基因组扫描分析

摘 要：注意缺损多动障碍（ADHD）是儿童期多见行为障碍。男孩发病多于女孩。家系、双生儿和寄养子研究显示该障碍发生具有遗传基础。但是病因尚不清楚。分子遗传学和药理学研究表明ADHD涉及到多巴胺和去甲肾上腺素等神经递质系统,一系列报告发现ADHD与多巴胺D4受体（DRD4）、多巴胺转运体（DAT1）和儿茶酚-O-甲基转移酶（COMT）等基因相关联。我们以往研究表明ADHD与X染色体上DXS7位点和MAOA基因相关联,而DXS7是紧密连锁于MAO基因。依此假设,我们应用基因组扫描技术探讨ADHD在X染色体上易感位点。采用TDT方法分析X染色体上48个DNA标志的多态性与中国人群中84个ADHD核心家系间的连锁关系,ADHD诊断依据DSM-III-R标准。TDT分析结果观察到如下位点与ADHD相连锁,DXS1214(TDT:χ2=18.1,df=7, P<0.01), DXS8102(TDT: χ2=7.9, df=3, P<0.05),DXS1068(TDT: χ2=21.9, df=9, P<0.01), DXS8015(TDT:χ2=14.6, df=7, P<0.05),DXS1059(TDT: χ2=27.8, df=10, P<0.01) 和DXS8088(TDT:χ2=20.4, df=3, P<0.01).研究资料提示X染色体上Xp11.4-Xp21和Xq23区域可能存在ADHD的易感基因。     

一个先天性眼球震颤家系致病基因的初步定位

为确定一个X染色体显性遗传先天性眼球震颤家系的致病基因与X染色体的连锁关系, 选用X染色体上的DXS1214、DXS1068、DXS993、DXS8035、DXS1047、DXS8033、DXS1192和DXS1232共8个微卫星DNA标记对该家系进行基因扫描与基因分型,并利用LINKAGE等软件包对基因分型结果进行分析,探讨该家系致病基因与X染色体的连锁关系。 两点连锁分析时X染色体短臂4个基因座最大LOD值均小于-1,不支持与该家系致病基因连锁; X染色体长臂4个基因座中最大LOD值达到2,提示存在较大的连锁可能性。该家系的致病基因可初步定位于X染色体长臂,且提示Xq26-Xq28区间附近可能是先天性眼球震颤一个共同的致病基因座,但区间范围仍较大,仍须进一步选择合适的微卫星标记进行精确的定位以缩小候选基因的筛查范围。Abstract： To investigate the relationship between X chromosome and obligatory gene of a pedigree with congenital nystagmus,we used the following markers: DXS1214、DXS1068、DXS993、DXS8035、DXS1047、DXS8033、DXS1192 and DXS1232.Genome screening and genotyping were conducted in this pedigree of congenital nystagmus, and linkage analysis by LINKAGE package was used to determine the potential location. The linkage was not found on the Xp ( All LOD score <-1) but on Xq (the maximum LOD score=2). The related gene of this pedigree was located on the long arm of X chromosome. We demonstrate that Xq26-Xq28 is a common locus for CMN. It bring us closer to the identification of a gene responsible for X-linked CMN.     

广州地区106例汉族人群MICA和MICB微卫星基因座 单体型研究 The Study on the Haplotype of MICA and MICB Microsatellite Locus In Guangzhou Han Population

利用聚合酶链反应和荧光（6－FAM）自动化检测技术对广东地区汉族106例无亲缘关系样本进行MICA基因外显子5和MICB基因内含子1微卫星基因座多态性及其单体型分布调查。根据群体资料估算两者间的单体型频率、连锁不平衡参数、相对连锁不平衡参数。结果显示，广州地区汉族人群MICA和MICB微卫星基因座基因型分布符合Hardy-Weinberg平衡法则，共检出MICA微卫星基因座 5个等位基因， MICB微卫星基因座14个等位基因。其中MICA A5基因频率最高（0.2877），A4基因频率最低（0.1321）。MICB CA14等位基因频率最高（0.3255），CA19、CA28等位基因频率最低（0.0047），未检出CA27。21种MICA－MICB单体型频率大于1%(连锁不平衡参数>0), 其中单体型A5－CA14 (16.73%), A5.1－CA18 (8.75%), A4－CA26(3.76%)，A9－CA15(3.66%)和A6－CA21(2.61%)为强连锁常见单体型（χ2>3.84, P<0.05）。广州地区汉族人群MICA和MICB微卫星基因座多态性和单体型分布有其自身特点，MICA和MICB微卫星基因座适合做为遗传标志，用于人类学、遗传疾病基因连锁分析、法医学亲子鉴定和个体识别等研究领域。Abstract: This study is to investigate genetic polymorphisms and haplotypes of microsatellite locus in the exon 5 of the MICA gene and intron 1 of the MICB gene based on 106 samples of Guangzhou Han Population by polymerase chain reaction and fluorescent technique (6-FAM). The corresponding haplotype frequencies, linkage disequilibria values and relative linkage disequilibria values were estimated based on population data. The results show that the genotype distributions of MICA and MICB microsatellite meet Hardy-Weinberg equilibrium in Guangdong Han population. In total, 5 alleles of MICA microsatellite locus and 14 alleles of MICB microsatellite locus were observed. MICA A5 was the most common allele (0.2877), whereas A4 was the least popular one (0.1321). MICB CA14 was the most common allele (0.3255), and CA19 and CA28 were the least popular ones (0.0047). CA27 was not observed. Twenty-one kinds of MICA-MICB haplotypes occurred at frequencies of more than 1% (linkage disequilibria value>0). The common MICA-MICB haplotypes were A5-CA14（16.73％）, A5.1- CA18 (8.75%), A4- CA26(3.76%)，A9-CA15(3.66%) and A6-CA21(2.61%)（χ2>3.84, P<0.05）, and they were strong linkage disequilibria. The polymorphisms and haplotypes distributions of MICA and MICB microsatellite locus in Guangzhou Han population have their own genetic characteristics. The microsatellite locus of the exon5 of the MICA gene and intron 1 of the MICB gene could be used as the genetic markers in the studies of anthropology, linkage analysis of genetic disease genes, individual identification and paternity test in forensic medicine.     

秦巴山区汉族人群DXS8027基因座的多态性分布研究

为了解秦巴山区汉族人群的DXS8027微卫星序列的遗传多态性,获得该基因位点的群体遗传学数据.采集秦巴山区汉族人群无关个体静脉血样550份,EDTA抗凝,用酚一氯仿法抽提基因组DNA,PCR扩增目的片段,8%非变性聚丙烯酰胺凝胶电泳,0.1%硝酸银(AgNO3)染色分型.结果,在秦巴山区人群中共检出9种不同的DXS8027等位基因,整体人群的基因频率符合Hardy-Weinberg平衡(P＞0.05),并具有较高的杂合度(Het=0.7968).虽然男性和女性间等位基因分布不一致(χ2=30.242,P＜0.01),但在不同地域同性别人群间、不同地域的全体研究人群间无差异(χ2=4.703,P＞0.05;χ2=14.952,P＞0.05;χ2=15.2,P＞0.05);比较秦巴山区和欧洲人群的DXS8027等位基因,发现两者之间存在极显著差异(χ2=37.572,P＜0.01).这些结果为进一步研究该位点在不同人群中的分布提供了基础数据.     

广州地区106例汉族人群MICA和MICB微卫星基因座 单体型研究

利用聚合酶链反应和荧光（6－FAM）自动化检测技术对广东地区汉族106例无亲缘关系样本进行MICA基因外显子5和MICB基因内含子1微卫星基因座多态性及其单体型分布调查。根据群体资料估算两者间的单体型频率、连锁不平衡参数、相对连锁不平衡参数。结果显示,广州地区汉族人群MICA和MICB微卫星基因座基因型分布符合Hardy-Weinberg平衡法则,共检出MICA微卫星基因座 5个等位基因, MICB微卫星基因座14个等位基因。其中MICA A5基因频率最高（0.2877）,A4基因频率最低（0.1321）。MICB CA14等位基因频率最高（0.3255）,CA19、CA28等位基因频率最低（0.0047）,未检出CA27。21种MICA－MICB单体型频率大于1%(连锁不平衡参数>0), 其中单体型A5－CA14 (16.73%), A5.1－CA18 (8.75%), A4－CA26(3.76%),A9－CA15(3.66%)和A6－CA21(2.61%)为强连锁常见单体型（χ2>3.84, P<0.05）。广州地区汉族人群MICA和MICB微卫星基因座多态性和单体型分布有其自身特点,MICA和MICB微卫星基因座适合做为遗传标志,用于人类学、遗传疾病基因连锁分析、法医学亲子鉴定和个体识别等研究领域。Abstract: This study is to investigate genetic polymorphisms and haplotypes of microsatellite locus in the exon 5 of the MICA gene and intron 1 of the MICB gene based on 106 samples of Guangzhou Han Population by polymerase chain reaction and fluorescent technique (6-FAM). The corresponding haplotype frequencies, linkage disequilibria values and relative linkage disequilibria values were estimated based on population data. The results show that the genotype distributions of MICA and MICB microsatellite meet Hardy-Weinberg equilibrium in Guangdong Han population. In total, 5 alleles of MICA microsatellite locus and 14 alleles of MICB microsatellite locus were observed. MICA A5 was the most common allele (0.2877), whereas A4 was the least popular one (0.1321). MICB CA14 was the most common allele (0.3255), and CA19 and CA28 were the least popular ones (0.0047). CA27 was not observed. Twenty-one kinds of MICA-MICB haplotypes occurred at frequencies of more than 1% (linkage disequilibria value>0). The common MICA-MICB haplotypes were A5-CA14（16.73％）, A5.1- CA18 (8.75%), A4- CA26(3.76%),A9-CA15(3.66%) and A6-CA21(2.61%)（χ2>3.84, P<0.05）, and they were strong linkage disequilibria. The polymorphisms and haplotypes distributions of MICA and MICB microsatellite locus in Guangzhou Han population have their own genetic characteristics. The microsatellite locus of the exon5 of the MICA gene and intron 1 of the MICB gene could be used as the genetic markers in the studies of anthropology, linkage analysis of genetic disease genes, individual identification and paternity test in forensic medicine.     

短串联重复序列D7S2201基因座的群体遗传学研究

用扩增片段长度多态性技术分析短串联重复序列D7S2201基因座的遗传多态性,在262个中国成都地区汉族无关个体及119个泰国曼谷地区泰人无关个体中分别发现7个和5个等位基因,首次获得该基因座在两群体中的频率分布,其等位基因片段大小范围为100～124bp。两群体的基因型频率分布均符合Hardy Weinberg平衡。该基因座在两群体中的个人识别能力（PD）、杂合度（H）、多态性信息含量（CPI）及非父排除率（PE）分别为0.7038、0.5992、0.4789、0.2900和0.7351、0.5882、0.5012、0.2770。家系调查证实了等位基因的传递遵循孟德尔遗传规律。χ2检验表明两群体间等位基因频率分布无显著性差异。 Abstract：The polymorphism of a new short tandem repeat (STR) locus D7S2201 was analyzed by using AmpFLP. Seven alleles were observed in 262 unrelated Chinese individuals living in Chengdu and five alleles in 119 unrelated Thai individuals living in Bangkok, the ranges of fragment size were 100～124bp. The genotypes distributions of D7S2201 locus in the two populations were in accordance with Hardy Weinberg equilibrium. The discriminating power (PD), observed heterozygosity (H), polymorphism information content (CPI) and power of exclusion (PE) were 0.7038, 05992, 04789, 02900 in Chinese population and 0.7351, 0.5882, 0.5012, 0.2770 in Thai population respectively. Family studies confirmed Mendelian inheritance of alleles. No significant difference was observed between the two populations.     

中国新疆维吾尔族DXS101遗传多态性研究

目的:研究DXS101位点在中国新疆维吾尔族群体中的遗传结构分布特征。方法:采用PCR扩增,变性聚丙烯酰胺凝胶电泳结合银染显带技术,检测100名(女42,男58)维吾尔族无关个体DXS101位点等位基因及基因型频率分布。结果:在女性样本中,DXS101位点检出9种等位基因和17种基因型;在男性样本中,DXS101位点检出7种等位基因。该位点在女性中的个体识别率为0.8937,多态信息量为0.8072,杂合度为0.8156,在男性中的个体识别率为0.6674。结论:群体遗传多态性指标显示DXS101位点在新疆维吾尔族群体中具有较高多态性,在维吾尔族群体法医学个体识别、亲权鉴定及群体遗传学研究中有重要应用价值。     

Association of three single nucleotide polymorphisms at the SIX1-SIX6 locus with primary open angle glaucoma in the Chinese population

This study investigated the genetic association of three single nucleotide polymorphisms(SNPs; rs10483727, rs33912345, and rs146737847) at the SIX1-SIX6 locus with primary open angle glaucoma(POAG) in the Chinese population. A total of 866 subjects with POAG(685 high-tension glaucoma(HTG) and 181 normal-tension glaucoma(NTG)) and 266 control individuals were included. Significant genetic association was identified for rs10483727 in HTG(P=0.02; odds ratio(OR)=1.31), NTG(P=7.41×10~(-6); OR=2.71), and POAG(i.e., HTG and NTG combined; P=0.001; OR=1.44). rs33912345 was also significantly associated with HTG(P=0.008; OR=1.36), NTG(P=2.72×10~(-6); OR=2.27), and POAG(P=3.84×10~(-4); OR=1.49). The rare SIX6 mutation, rs146737847, was not found in the subjects enrolled in this study. Stratification by patient age identified that both rs10483727 and rs33912345 were significantly associated with NTG in patients aged above 40 years(P=2.08×10~(-5); OR=2.28), whereas in patients aged between 20–40 years, rs33912345 was significantly associated with NTG(P=0.017; OR=2.06). In HTG, the genetic associations for both rs10483727 and rs33912345 were significant in patients aged between 20–40 years(P=0.006; OR=1.56) but not in those aged above 40 years(P=0.118, OR=1.21 and P=0.042, OR=1.29, respectively). This study replicated the association of POAG with two SNPs at the SIX1-SIX6 locus and demonstrated that SNPs, rs10483727 and rs33912345, are significantly associated with POAG, especially with NTG in patients aged above 40 years.     

中国畲族群体D17S30位点遗传多态性研究

采用聚合酶链反应 (PCR)技术对中国畲族群体270名无关个体D17S30位点的VNTR进行了研究,共检出12个等位基因,片段大小为168bp-1008bp,基因频率为0.0056-0.3259,杂合度为79.10%,父权排除率为0.4358。家系分析表明,扩增片段按孟德尔方式遗传。统计学分析证明,本资料符合Hardy-W einberg平衡定律(x2=79.97,v=66,P=0.1158>0.05)。 Abstract:The variable number of tandem repeat(VNTR)of D17S30 locus in 270 unrelated individuals of She ethnic group was studied by polymerase chain reaction(PCR).The results showed that 12 alleles were detected and their sizes ranged from 168bp to 1 008bp.The allele frequencies were 0.0056~0.3259,the heterozygosity of this locus was 79.10% and the paternity exclusion probability was 0.4358.The number of D17S30 VNTR allele and allele frequency of She were different from those of Han ethnic group in Mendelian Law.Statistical analysis demonstrated that their geneotypes were consistent with Hardy-Weinberg equilibrium(x2=79.97,v=66,P=0.1158>0.05).     

Association of polymorphisms of Nramp1 gene with immune function and production performance of large white pig

The present research was designed to study the association of polymorphism of natural resistance-associated macrophage protein1 (Nramp1) with some immune function and the production performance in Large White pig. The PCR-RFLP technique was applied to analyze the correlation between the polymorphisms of Nramp1 gene and immune function [value of Polymorphonuclear Leukocytes (PMN) obtained by Nitroblue Tetrazolium (NBT) Reduction and effect of Cytotoxin in Monocyte] and production performance in 165 Large White pigs. The results showed that there was one Nde I restriction locus in Large White pig, and both values of PMN by NBT Reduction and effect of Cytotoxin in Monocyte in genotype BB were higher than those in genotype AB (P<0.05). Simultaneously, the weight of 180-day-old pigs with genotype BB was higher than that with genotype AB (P<0.05). The results indicated that there was a significant correlation between different genotypes of Nramp1 gene and Immune function and production performance, and it can be regarded as a candidate gene of disease resistance. All these results provide valuable reference to further studies of pig disease resistance.     

广东少数民族Morquio综合征StuI位点的RFLP分析

研究广东少数民族群体GALNS基因StuI位点的遗传多态性以及该位点等位基因片段传递的规律,为今后的连锁分析打下基础。采用PCR-RFLP方法,对72例无血缘关系的健康广东少数民族个体的144条染色体和3个家系9位成员的18条染色体进行检测,然后用χ2检验进行统计学处理。等位基因片段D1的频率为0.70, D2为0.30,杂合率为29%,D1、D2的传递规律与理论上预计的完全符合。广东少数民族群体中StuI位点具有多态性,其基因频率（D1和D2）与国外高加索群体的有显著差别,与日本群体及中国南方汉族群体的则无显著差别;而杂合率与高加索群体及日本群体的均有显著差异,但与中国南方汉族群体的则无显著差异。 Abstract:To investigate the genetic polymorphism of the StuI site in the GALNS gene from a national minority population in Guangdong and to study the mode of transmission of alleles,PCR-RFLP was used to analyze 144 chromosomes from 72 Guangdong unrelated healthy national minority individuals,and the genotypes of members in three families.To compare the frequencies and heterzygosity between Guangdong national minority people and Caucasians,Japanese and Chinese Han people by using χ2 test.The frequency of allele D1(295bp) was 0.70,allele D2(138 plus 157 bp)0.30,the heterozygosity was 29%.The genotypes of each member of all families detected were completely agreement with the theorical assessment.The site of StuI in the GALNS gene from national minority population in Guangdong has polymorphism.There is significant difference between Guangdong national minority population and Caucasians in Western countries,but no significant difference was found between Guangdong national minority population and Japanese and Chinese Han population.In addition,there is significant difference between Guangdong national minority population and Caucasians and Japanese in the heterzygosity,but no significant difference between Guangdong national minority population and Chinese Han population.The transmission of alleles was completely in agreement with the Mendelian genetic law.     

Association Between rs1344706 of ZNF804A and Schizophrenia:A Meta-analysis

Schizophrenia is one of the most serious mental diseases found in humans. Previous studies indicated that the single nucleotide polymorphism（SNP） rs1344706 in the gene ZNF804 A encoding zinc finger protein 804 A was associated with schizophrenia in Caucasian population but not in Chinese Han population. However, current results are conflicting in Asian population. In the present study, a meta-analysis was performed to revisit the association between rs1344706 and the risk of schizophrenia in Asian, Caucasian and other populations. Electronic search of Pub Med database identified 25 case–control studies with available genotype frequencies of rs1344706 for the meta-analysis,involving a total of 15,788 cases and 22,654 controls. A pooled odds ratio（OR） with 95% confidence interval（CI） was used to assess the association. The current meta-analysis showed an association between rs1344706 and schizophrenia in Caucasian populations（P = 0.028, OR = 1.138, 95% CI：1.014–1.278; P = 0.004 for heterogeneity） and Asian populations（P = 0.008, OR = 1.092, 95%CI： 1.023–1.165; P = 0.001 for heterogeneity）, but not in other populations（P = 0.286,OR = 1.209, 95% CI： 0.853–1.714, P = 0.120 for heterogeneity）. Egger’s test（P 〉 0.05） and Begg’s test（P 〉 0.05） are both suggestive of the lack of publication bias for the included studies. Thus, the absence of association in other populations suggests a genetic heterogeneity in the susceptibility of schizophrenia and demonstrates the difficulties in replicating genome-wide association study findings regarding schizophrenia across different ethnic populations. To validate the association between rs1344706 and schizophrenia, further studies with larger participant populations worldwide are needed.     

Association between VDR ApaI Polymorphism and Hip Bone Mineral Density Can Be Modified by Body Mass Index： A Study on Postmenopausal Chinese Women

Osteoporosis is a major public health problem for old people. Genetic factors are considered to be major contributors to the pathogenesis of postmenopausal osteoporosis. The vitamin D receptor (VDR) gene is a prominent candidate gene for the regulation of postmenopausal bone mass; however, despite extensive studies, controversy remains regarding its association with postmenopausal body mineral density (BMD) variation. In this study, a total of 260 healthy postmenopausal Chinese women were genotyped at the VDR ApaI locus using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Raw hip BMD was significantly associated with VDR ApaI polymorphism with and without adjusting for age (P=0.015 and 0.040, respectively). This genetic effect can explain 3.32% of hip BMD variation. However, the significant association vanished after correcting for both age and body mass index (BMI) (P=0.169). In addition, we observed a significant association between VDR ApaI polymorphism with unadjusted BMI(P=0.042) or BMI adjusted for age (P=0.049). The raw hip BMD was also found to be significantly correlated with BMI (r=0.517, P=0.0001), with BMI explaining 26.35% of the variation of hip BMD. All of these facts prompt us to conclude that the significant association between the VDR ApaI genotype and hip BMD may be modified by BMI in postmenopausal Chinese women. Our findings may partially explain the earlier inconsistent association results concerning the VDR gene and BMD, and highlight the importance of incorporating covariates such as BMI into osteoporosis association studies.     

Association between VDR Apal Polymorphism and Hip Bone Mineral Density Can Be Modified by Body Mass Index:A Study on Postmenopausal Chinese Women

Osteoporosis is a major public health problem for old people.Genetic factors are considered tobe major contributors to the pathogenesis of postmenopausal osteoporosis.The vitamin D receptor(VDR)gene is a prominent candidate gene for the regulation of postmenopausal bone mass;however,despite exten-sive studies,controversy remains regarding its association with postmenopausal body mineral density(BMD)variation.In this study,a total of 260 healthy postmenopausal Chinese women were genotyped at the VDRApaI locus using polymerase chain reaction(PCR)-restriction fragment length polymorphism (RFLP).Rawhip BMD was significantly associated with VDR ApaI polymorphism with and without adjusting for age(P=0.015 and 0.040,respectively).This genetic effect can explain 3.32% of hip BMD variation.However,the significant association vanished after correcting for both age and body mass index(BMI)(P=0.169).Inaddition,we observed a significant association between VDR ApaI polymorphism with unadjusted BMI(P=0.042)or BMI adjusted for age(P=0.049).The raw hip BMD was also found to be significantly corre-lated with BMI(r=0.517,P=0.0001),with BMI explaining 26.35% of the variation of hip BMD.All of thesefacts prompt us to conclude that the significant association between the VDR ApaI genotype and hip BMDmay be modified by BMI in postmenopausal Chinese women.Our findings may partially explain the earlierinconsistent association results concerning the VDR gene and BMD,and highlight the importance of incorpo-rating covariates such as BMI into osteoporosis association studies.     

通用线性模型筛选家禽生化多态遗传标记的探讨

本研究首次采用线性模型估计生化基因(表)型对产蛋量相关性状的效应,排除环境和遗传背景的差异,检测出效应显著的3种生化基因(表)型。Akp座位F型和Es-1座位AB型的开产蛋重显著降低, 效应的遗传本质有待于深入研究确认。 Tf位点对于36周龄体重的影响不属于基因多效或紧密连锁效应, 可能是距离较远基因连锁的结果,效应随基因间连锁与交换会在品系和世代间产生较大波动;或可能源于非控制误差。本研究还表明生化基因座位与数量性状基因位点(QTL)间的非紧密基因连锁可能大量存在, 但育种意义不大。 Abstract:The literature on associations between biochemical polymorphisms with a Mendelian basis and quantitative traitsis abundant,but it is often difficult to draw conclusions from results that vary in statistical significance and that are sometimes conflicting.Linear models were found capable in estimating associated effects of biochemical genes,precluding deviations due to environmental and population differences.Three biochemical gene- or phenotypes were detected to be significantly associated with laying-related traits.F of Akp locus and AB of Es-1 locus showed large associated effects on egg weight at onset of lay as the result of pleiotrophy or close linkage,or caused by heterogeneity,whereas association of BB at Tf locus with body weight at 36 weeks of age could be due to loose linkage or non-controlled errors which exhibited large variations between populations and possibly through generations Many biochemical loci were also revealed to be occasionally associated with laying-related traits,but few of them could be of breeding importance.     

Hereditary neuralgic amyotrophy: evidence for genetic homogeneity and mapping to chromosome 17q25

Hereditary neuralgic amyotrophy (HNA) is a rare autosomal dominant disorder on chromosome 17q, associated with recurrent, episodic, painful brachial plexus neuropathy. Dysmorphic features, including hypotelorism, long nasal bridge and facial asymmetry, are frequently associated with HNA. To assess genetic homogeneity, determine the cytogenetic location, and identify flanking markers for the HNA locus, six pedigrees were studied with multiple DNA markers from distal chromosome 17q. The results in all pedigrees supported linkage of the HNA locus to chromosome 17. A maximum combined lod score (Ζ = 10.94, ￡ = 0.05) was obtained with marker D17S939 and the maximum multipoint lod score was 22.768 in the interval defined by D17S802– D17S939. An analysis of crossovers placed the HNA locus within an approximate 4.0-cM interval flanked by D17S1603 and D17S802. Analysis of DNA from a human/mouse somatic cell hybrid with linked markers suggests that band 17q25 harbors the HNA locus. These results support genetic homogeneity within HNA and define a specific interval and a precise cytogenetic location in chromosome 17q25 for this disorder. Received: 24 June 1997 / Accepted: 21 August 1997     

黄瓜复雌花等6对基因间连锁遗传关系的研究

为探索黄瓜复雌花基因mp、有限生长基因de、叶片皱缩基因cr、叶片无毛基 因gl-2、果皮多刺基因ns和果实有棱基因Tu间的独立或连锁遗传关系,试验选用了带上述6对基因的黄瓜纯合亲本NCG128、NCG 157、WI 275 7和NCG 042,以这些亲本配制4个杂交组合,获得F1,F2,BC1a和BC1b代群体,采用孟得尔遗传公式和计算机程序分析参试性状在各杂交后代中的基因型分离情况。结果表明:基因mp和de,cr和gl-2,cr和Tu,Tu和gl-2,Tu和ns间存在连锁遗传关系,它们的基因间距离分别为0.21,0.12,0.38,0.24,0.32cM(厘摩)。 Abstract:To study the linkage inheritance among gene mp for multi-pistillate flowering,de for determinate growth type,cr for crinkled leaf,gl-2 for glabrous leaf,ns for numerous spine,and Tu for tuberculate fruit in cucumber,the inbred NCG128,NCG157,WI2757 and NCG 042 were used as parents for 4 coombinations in the experiment.The traits of these genes were measured in field and the data was analyzed with a computer program SASGENE.The result indicated that the gene mp and de,cr and gl-2,cr and Tu,Tu and gl-2,Tu and ns had linkage relationship,and the distance between them was 0.21,0.12,0.38,0.24,0.32cM,respectively.     

Habitat productivity is a poor predictor of body size in rodents

The"resource availability hypothesis"predicts occurrence of larger rodents in more productive habitats.This prediction was tested in a dataset of 1,301 rodent species.We used adult body mass as a measure of body size and normalized difference vegetation index(NDVI)as a measure of habitat productivity.We utilized a cross-species approach to investigate the association between these variables.This was done at both the order level(Rodentia)and at narrower taxonomic scales.We applied phylogenetic generalized least squares(PGLS)to correct for phylogenetic relationships.The relationship between body mas and NDVI was also investigated across rodent assemblages.We controlled for spatial autocorrelation using generalized least squares(GLS)analysis.The cross-species approach found extremely low support for the resource availability hypothesis.This was reflected by a weak positive association between body mass and NDVI at the order level.We find a positive association in only a minority of rodent subtaxa.The best fit GLS model detected no significant association between body mass and NDVI across assemblages.Thus,our results do not support the view that resource availability plays a major role in explaining geographic variation in rodent body size.