八倍体小滨麦与缺体小麦杂交的细胞遗传学研究

八倍体小滨麦与缺体小麦杂交和回交,其后代ＢＣ１Ｆ１与Ｆ２相比较,染色体分离范围小,有利于４１条染色体类型的分离,若用异源双单体附加作父本与缺体回交,４１条染色体类型的分离率还会提高２倍左右;单体代换在自交世代的传递率为３１．９１％,二体代换的分离率为１９．３７％,异染色体的丢失率为２９．３４％;二体代换在自交世代的传递率为８５．２６％,异染色体的丢失率为９．２１％;ＰＭＣＭＩ染色体构型为２０．７６”＋０．３１’＋０．０３＂＋０．０１””,相对紊乱系数为０．０１,２ｎ＝２１”的细胞占８６．０９％。选育的二体代换系,不同程度地表现出大穗、多花、优质、抗多种病害等滨麦的优良性状。     

八倍体小滨麦染色体组构成的分子细胞遗传学研究

应用基因组荧光原位杂交技术对６种类型的八倍体小滨麦（ｏｃｔｏｐｌｏｉｄ Ｔｒｉｔｉｌｅｙｍｕｓ）的染色体结构成进行了分子细胞遗传学分析。结果表明,６种八倍体小滨麦的体细胞染色体数目均为２ｎ＝５６。用滨麦（Ｌｅｙｍｕｓ ｍｏｌｌｉｓ （Ｔ ｒｉｎ．） Ｈａｔａ）（染色体组为ＪＪＮＮ）ＤＮＡ作控针进行原位杂 时,Ｍ８４２－４、Ｍ８４２－８、Ｍ８４２－１２、Ｍ８４２－１３和Ｍ８４２－１６等５种类型八倍体     

八倍体小滨麦与普通小麦杂交后代的细胞遗传学研究

本文对八倍体小滨麦与普通小麦杂交后代的细胞遗传学及附加染色体的传递及丢失规律进行了研究和讨论。结果表明,ＢＣ１Ｆ１与Ｆ２相比较,染色体分离范围小,并且分离向染色体数目减少偏移,有利于４３、４４条染色体的分离;双单体附加和单体附加后代异染色体丢失严重,分别为６５．７９％和６１．９９％,双单体附加分离出单体附加占１０．５３％,单体附加的传递率为２６．９２％,单体附加后代分离出的二体附加为５．５６％,二体附加自交世代中,异染色体的丢失率为２９．０３％,传递率为５６．４５％;ＰＭＣＭＩ染色体构型为２１．７０Ⅱ＋０．０５Ⅰ＋０．０２Ⅲ＋０．０１Ⅳ,２ｎ＝２２Ⅱ的细胞占８８．９６％。选育的附加系及具４２条染色体的株系,不同程度地表现出大穗、大粒、优质、抗病等滨麦的优良性状。     

八倍体小偃麦与普通小麦杂交后代花药培养的研究

本试验研究了八倍体小偃麦与普通小麦杂交后代愈伤组织的诱导频率、雄核发育和秋水仙碱诱导小孢子染色体加倍的效果。结果表明:八倍体小偃麦与普通小麦杂种F_1愈伤组织的产量具有明显的杂种优势;其雄核发育存在均等分裂和不均等分裂等类型,这与小麦中的观察结果相似;在培养基中加入秋水仙碱可以有效地诱导小孢子第一次有丝分裂时染色体加倍。     

八倍体小偃麦与普通小麦杂交后代的细胞遗传学研究

本研究以八倍体小偃麦小偃7430和普通小麦鲁麦1号为亲本,对其杂种的6个世代(F_1、F_2、F_3、B_1F_2、B_1F_3、B_2F_2)的细胞遗传学进行了研究。结果表明:从杂种F_1开始,随着自交和回交世代的增进,杂种后代植株染色体数逐渐减少;植株染色体数越多,减数分裂中期Ⅰ单价体出现频数、多价体出现类型及频数也越多,但二价体出现个数基本稳定在21左右。通过细胞学鉴定和性状观察,从小偃7430与鲁麦1号杂交的不同世代中选出了几个二体异附加株,有的农艺性状较好;还选出了农艺性状好,细胞学基本稳定的2n=42的株系,初步实现了将偃麦草的某些特异染色体或优良基因导入普通小麦遗传背景的目的。     

八倍体小偃麦染色体组分析

本文对普通小麦与长穗偃麦草(Elytrigia elongata=Agropyron elongatum.2n=70)杂交选育出来的5个八倍体小偃麦的染色体组进行了研究。通过八倍体小偃麦与普通小麦杂交,八倍体小偃麦相互间杂交,观察了杂种F_1花粉母细胞减数分裂行为。根据观察结果,讨论了长穗偃麦草染色体组的构成,认为长穗偃麦草的染色体组为E_1E_2F_2F_2N较为合适。在此基础上,确定了5个八倍体小偃麦的染色体组:7430为ABDE_1,68为ABDF_1,693为ABDF_1,7631为ABDF_2,784为ABDN。另外,还讨论了八倍体小偃麦染色组的重组问题。     

余倍体小滨麦与普通小麦杂交后代的细胞遗传学研究

本文对八倍体小滨麦与普通小麦杂交后代的细胞遗传学及附加染色体的传递及丢失规律进行了研究和讨论。结果表明,ＢＣ１Ｆ１与Ｆ２相比较,染色体分离范围小,并且分离向染色体数目减少偏移,有利于４３、４４条染色体的分离;双单体附加和单体附加后代异染色体丢失严重,分别为６５．７９％和６１．９９％,双单体附加分离出单体附加占１０．５３％,单体附加的传递率为２６．９２％,单体附加后代分离出的二体附加为５．５６％,二     

八倍体小偃麦与普通小麦杂交选育抗旱小麦品种的研究

利用八倍体小堰麦与普通小麦杂交,通过连续选择选育出抗旱小麦品种小偃５９７,试验结果表明,小偃５９７抗旱,叶组织细胞膜的稳定性（７．６％）,叶片持水力（５１．６０％）和叶组织相对含水量（７７．０６％）高,株高８５ｃｍ,白粒,角质,品质优。每公顷６７５０ｋｇ。     

八倍体小偃麦与普通小麦杂交育种的研究

利用八倍体小偃麦与普通小麦杂交,创造了一些异附加系和异代换系,选育出一个特早熟、矮秆、抗病、高产、优质小麦新品种－“早优５０４”。总结了八倍体小偃麦与普通小麦杂交育种程序。     

小麦背景中簇毛麦6V染色体的遗传稳定性及其在配子中的传递

小麦－簇毛麦６Ｖ二体附加系,６Ａ（６Ｖ）二体代换系,６Ａ＾Ｌ．６Ｖ＾ｓ二体易位系在细胞学上是基本稳定的６Ｖ,６Ａ＾Ｌ．６Ｖ＾ｓ染色体能够通过配子稳定地传递给后代,在杂合状态下,带有６Ｖ的配子传递率普遍显著下降,在单体附加系（２１”Ｗ＋６Ｖ）中,６Ｖ通过雌配子的传递率（１１．３％）高于通过雄配子的传递率（５．９％）,在单体代换系（２０”Ｗ＋６Ａ－６Ｖ）中,６Ｖ通过雌配子的传递率（１０．４％）低于通过     

水稻第4号染色体不同位置的Ds转座子转座行为的分析

使用农杆菌介导的方法转化粳稻品种中花11,构建了在第4号染色体不同位置插入了Ds（dissociation）因子的水稻转化群体和带有Ac（activator）转座酶基因的转化植株。将携带了Ac转座酶基因的植株与不同Ds转化植株杂交,杂交F1代同时带有Ac转座酶和Ds因子（Ac／Ds植株）。用PCR方法检测了杂交F1代Ds的切离频率,结果发现靠近第4号染色体着丝粒附近的Ds转座子切离频率低,而靠近第4号染色体末端区域的Ds转座子切离频率高,这表明Ds转座子的原始插入位置对其杂交后代的切离频率有很大的影响,推测与原始插入位点附近的染色体结构有关。     

Genetic variation at minisatellite loci D1S7, D4S139, D5S110 and D17S79 among three population groups of eastern India

Genetic variation at four minisatellite loci D1S7, D4S139, D5S110 and D17S79 in three predominant population groups of eastern India, namely Brahmin, Kayastha and Garo, are reported in this study. The Brahmin and Kayastha are of Indo-Caucasoid origin while the Garo community represents the Indo-Mongoloid ethnic group. The methodology employed comprised generation of HaeIII-restricted fragments of isolated DNA, Southern blotting, and hybridization using chemiluminescent probes MS1, pH30, LH1 and V1 for the four loci. All four loci were highly polymorphic in the population groups. Heterozygosity values for the four loci ranged between 0.68 and 0.95. Neither departure from Hardy-Weinberg expectations nor evidence of any association across alleles among the selected loci was observed. The gene differentiation value among the loci is moderate (G_ST = 0.027). A neighbour-joining tree constructed on the basis of the generated data shows very low genetic distance between the Brahmin and Kayastha communities in relation to the Garo. Our results based on genetic distance analysis are consistent with results of earlier studies based on serological markers and linguistic as well as morphological affiliations of these populations and their Indo-Caucasoid and Indo-Mongoloid origin. The minisatellite loci studied here were found to be not only useful in showing significant genetic variation between the populations but also to be suitable for human identity testing among eastern Indian populations.     

Evaluation of mesh- and binary-based contour propagation methods in 4D thoracic radiotherapy treatments using patient 4D CT images

Based on four dimensional (4D) computed tomography (CT) images, mesh- and binary-based contour propagation algorithms for 4D thoracic radiotherapy treatments were evaluated. Gross tumor volumes (GTVs), lungs, hearts and spinal cords on the CT images at the end-exhale and end-inhale phases for six patients were delineated by the physician. All volumes of interest (VOIs) were automatically propagated from the end-exhale phase to the end-inhale phase using two propagation methods. The propagated VOIs were quantitatively compared with the VOIs contoured at the end-inhale phase by the physician using Dice Similarity Coefficient (DSC), Mean Slicewise Hausdorff Distance (MSHD), Center Of Mass (COM) displacement and volume difference. A two-sided Student’s t test was implemented to examine the significance of the differences between the results obtained from the two algorithms. For GTVs, statistically significant differences between the two algorithms were not observed. For all the other VOIs, the mesh-based method showed higher mean DSCs for the heart, left lung, right lung and spinal cord, lower mean MSHD for the spinal cord, lower mean COM displacement for the heart, and lower mean volume differences for the left lung, right lung and spinal cord with statistically significant differences than the binary-based method. The running time for propagation was approximately 3 s and 3 min for the mesh- and binary-based methods, respectively. Collectively, the mesh-based algorithm provides superiorities in running time and reliability for contour propagation in 4D radiotherapy.     

Association of polymorphisms in the dopamine D4 receptor gene and the activity-impulsivity endophenotype in dogs

A variable number of tandem repeats (VNTR) polymorphism in exon 3 of the human dopamine D4 receptor gene ( DRD4 ) has been associated with attention deficit hyperactivity disorder (ADHD). Rodents possess no analogous repeat sequence, whereas a similar tandem repeat polymorphism of the DRD4 gene was identified in dogs, horses and chimpanzees. Here, we present a genetic association study of the DRD4 VNTR and the activity-impulsivity dimension of the recently validated dog-ADHD Rating Scale. To avoid false positives arising from population stratification, a single breed of dogs (German shepherd) was studied. Two DRD4 alleles (referred to as 2 and 3a ) were detected in this breed, and genotype frequencies were in Hardy–Weinberg equilibrium. For modelling distinct environmental conditions, 'pet' and 'police' German shepherds were characterized. Police German shepherds possessing at least one 3a allele showed significantly higher scores in the activity-impulsivity dimension of the dog-ADHD Rating Scale than dogs without this allele ( P  = 0.0180). This difference was not significant in pet German shepherds. To the best of our knowledge, this is the first report of an association between a candidate gene and a behaviour trait in dogs, and it reinforces the functional role of DRD4 exon 3 polymorphism.     

The study of CTLA-4 and vitamin D receptor polymorphisms in the Romanian type 1 diabetes population

Several studies suggested that part of the genetic susceptibility for Type 1 diabetes (TIDM) is encoded by some polymorphisms of CTLA-4 gene (2q33) and of Vitamin D Receptor gene (VDR; 12q12-14). Our aim was to assess their contribution to TIDM genetic susceptibility in the Romanian population. We typed CTLA-4 49 A/G and VDR Fok I (F/f), Apa I (A/a) and Taq I (T/t) polymorphisms by Sequence Specific Primer PCR (SSP-PCR) in 204 Romanian diabetic families (756 individuals: 212 TIDM probands and 544 unaffected parents and siblings). We studied alleles transmission using the Transmission Disequilibrium Test (TDT). We found an increased transmission of CTLA-4 49G allele to diabetics (54.8%, p=0.11). The transmission of F (56.1%, p=0.063), a (55.7%, p=0.061) and T (51.8%, p=0.37) alleles of VDR gene to diabetics was increased but did not reach statistical significance. In conclusion we found the same increased transmission of CTLA-4 49 G allele to diabetics as previously reported. VDR Foq I F allele seems to be predisposing while Taq I T allele seems to be protective.     

A longitudinal study of digit ratio (2D:4D) and other finger ratios in Jamaican children

It has been hypothesised that the ratio between the length of the 2nd and 4th digits (2D:4D) is a correlate of prenatal sex steroids, and this relationship is strongest for the right hand. Furthermore, it has been suggested that 2D:4D is sexually dimorphic, the dimorphism is determined early, and 2D:4D among children is stable with growth. Here, we present the first longitudinal study of right and left hand 2D:4D. Our sample was 108 (54 males) Jamaican children. The first measurements were made in 1998 when mean age was 9.68 +/- 1.39 years, and a second set of measurements were made in 2002. We found that: (i) there was a small increase in 2D:4D with age which was lowest in the right hand; (ii) 2D:4D was sexually dimorphic, the means for males and females differed in the same direction in the 1998 and 2002 samples, and the sex difference was significant in the 1998 but not in the 2002 sample; (iii) the correlation between the 1998 and 2002 measurements of 2D:4D was high, indicating that rank order of the ratio was stable across year groups; and (iv) the rate of change in 2D:4D did not differ significantly across year groups. We conclude that 2D:4D increases slightly with age in children with the effect less marked for the right hand (i.e. the hand which is likely to show the strongest association with prenatal steroids), 2D:4D is sexually dimorphic from an early age, and the rank order of 2D:4D is stable in children. We discuss the implications of our findings for the status of 2D:4D as a correlate of prenatal sex steroids. The patterns of change in other finger ratios are also considered.     

2D:4D ratios in the first 2 years of life: Stability and relation to testosterone exposure and sensitivity

The relative lengths of the 2nd and 4th digits (2D:4D) may provide an easily measurable and stable anthropometric index of prenatal androgen exposure, but no study has examined the development of 2D:4D in infancy and the potential impact of neonatal testosterone levels. We collected 2D:4D ratios from 364 children between 0 and 2 years of age. Saliva samples were collected from 236 of these children 3 months after birth and analyzed for testosterone. In addition, 259 children provided DNA samples which were genotyped for the CAG repeat polymorphism in the androgen receptor. There was substantial variability across age in 2D:4D. Sex differences were small compared to adults and did not consistently reach statistical significance. This suggests that 2D:4D may not function well as a proxy measure of prenatal testosterone exposure in infancy. In addition, the interaction of salivary T and CAG repeats predicted right hand digit ratio at 12 months and left hand digit ratio at 12 months and 24 months in males. The interaction of salivary testosterone and CAG repeat length also predicted change in left hand 2D:4D from 2 weeks to 12 months in males. This suggests that 2D:4D in adults may reflect, in part, neonatal testosterone exposure. No significant relationships were observed within females. No significant relationships were observed when salivary testosterone and CAG repeats were examined independent of each other. Results have important implications for the design and interpretation of studies which use 2D:4D as a proxy measure of prenatal testosterone exposure.     

XPD和ECC1 基因多态性与进展期结直肠癌患者铂剂为基础化疗方案 治疗的毒副作用 *

目的:探讨着色性干皮病基因D(Xeroderma Pigmentosum D,XPD)和剪切修复交叉互补基因l(Excision Repair Cross Complementing Gene 1,ERCCl)多态性基因型与以铂类为基础的化疗方案治疗结直肠癌的毒副作用的关系。方法:采用聚合酶链反应--限制性片段长度多态性(Polymerase Chain Reaction-Restriction Fragment Length Polymorphism,PCR-RFLP)分析方法,对我院2010年12月至2013年12月应用含奥沙利铂方案治疗的42例汉族进展期结直肠癌患者的XPD和XRCCl的多态性基因型进行分析,比较不同基因型与临床病理因素及化疗不良反应的关系。结果:XPD、ERCC1的单核苷酸多态性(Single Nucleotide Polymorphism,SNP)分布与年龄、性别、淋巴转移、肿瘤的部位、化疗史、分化程度、器官转移个数差异无统计学意义(P>0.05);XPD基因型中,其中AA基因型以骨髓抑制、恶心呕吐为主,AG基因型以腹泻及肝肾损伤为主,GG基因型以神经毒性及口腔黏膜炎为主,差异有统计学意义(P<0.05);ERCC1基因型中,LG基因型以骨髓抑制、恶心呕吐及腹泻等症状为主,LL基因型以肝肾损伤、神经毒性及口腔黏膜炎为主,差异有统计学意义(P<0.05)。结论:XPD和ERCCl的基因型可能与结直肠癌铂类药物化疗的不良反应有关。