一个氨基糖苷类抗生素致聋家系线粒体DNA突变研究

应用PCR、PCR－SSCP和DNA序列分析等分子生物学技术,对一个有明确氨基糖苷类抗生素应用史的母系遗传耳聋家系共8人(包括聋人和听力正常者) 的线粒体DNA进行研究,结果显示,家系中有4份样品存在线粒体DNA 12S rRNA 1 555位点A→G的突变。提示线粒体DNA点突变是导致该家系致聋的主要因素之一。 Abstract:Blood samples were obtained from a pedigree with aminoglycoside antibiotic induced deafness.DNA was extracted from the isolated leukocytes.The mitochondrial DNA fragments were detected by PCR－SSCP and DNA sequencing.It was found that four individuals from the pedigree carried 1 555 A→G mutation.From our results,mitochondrial DNA mutation may be one of major factors in aminoglycoside antibiotic induced deafness.     

栽培稻×大颖野生稻F~2 多倍现象的细胞遗传学研究

A栽培稻(Oryza sativa)×大颖野生稻(Oryza grandiglumis)F2经细胞学鉴定为2n=4x=48, 即已由杂种F1的ACD异源三倍体变成了异源四倍体。研究了从粗线期到末期Ⅱ的染色体行为,结果表明,F2的染色体构型为异源节段异段类型,且异常染色体频率极高,合计为87.13%。各类异常染色体频率变化按比例大小依次为: 单价体,染色体拖曳,落后染色体,多价体,邻接型易位,不均等分离,桥,不分离和松散配对等。邻接型易位是本研究的中心论题。因邻接型易位的存在是F2花粉不育的一个重要原因, 也是产生节段异段染色体构型的重要原因;因邻接型易位带来相互易位,可供育种利用。 Abstract:The chromosome number in F2 of O.sativa×O.grandiglumis were 2n=4x=48.This showed that the allotriploid of hybrid F1 had been changed into allotetraploid in F2.The chromosome constitution of this allotetraploid remained to be determined.The chromosome behavior was studied during meiosis from pachytene to telophase II.Results showed that the chromosome configuration of F2 belonged to the type of the nodal section-allosection,and possessed very high rate of anomalous chromosome,the total rate of anomalous chromosome accounting for 87.13%.The frequency of anomalous chromosome were ranked as follows:univalent,chromosome straggling,lagging chromosome,polyvalent,adjoin translocation,unequal division,chromosome bridge,non-disjunction and loose pairing in descent order.The adjoin translocation was the topic in this study.With this translocation,no vitality gamentes were produced in F2.However,this is a mutual translocation,hence that is very useful for breeding.     

Induction and transmission of wheat-Haynaldia villosa chromosomal translocations

In order to develop more wheat-Haynaldia villosa translocations involving different chromosomes and chromosome segments of H. villosa, T. durum-H, villosa amphiploid was irradiated with ^60Co γ-rays at doses of 800, 1,200, and 1,600 rad. Pollen collected from the spikes 1, 2, and 3 days after irradiation were transferred to emasculated spikes of the common wheat cv. ‘Chinese Spring＇. Genomic in situ hybridization was used to identify wheat-H, villosa chromosome translocations in the M1 generation. Transmission of the identified translocation chromosomes was analyzed in the BC1, BC2, and BC3 generations. The results indicated that all three irradiation doses were highly efficient for inducing wheat-alien translocations without affecting the viability of the M1 seeds. Within the range of 800-1,600 rad, both the efficiency of translocation induction and the frequency of interstitial chromosome breakage-fusion increased as the irradiation dosage increased. A higher translocation induction frequency was observed using pollen collected from the spikes 1 day after irradiation over that of 2 or 3 days after irradiation. More than 70% of the translocations detected in the M1 generation were transmitted to the BC1 through the female gametes. All translocations recovered in the BC1 generation were recovered in the following BC2, and BC3 generations. The transmission ability of different translocation types in different genetic backgrounds showed an order of ‘whole-arm translocation 〉 small alien segment translocation 〉 large alien segment translocation＇, through either male or female gametes, In general, the transmission ability through the female gametes was higher than that through the male gametes. By this approach, 14 translocation lines that involved different H. villosa chromosomes have been identified in the BC3 using EST-STS markers, and eight of them were homozygous.     

Variation of B Chromosome Associated with Tissue Culture in Wheat-rye Cross

In vitro variation of B chromosomes was studied by examining the callus cells derived from the immature embryos from a cross of Chinese Spring wheat （Triticum aestivum L.） and Fin 7416 rye （Secale cereale L.） carrying two B chromosomes. In 40-d-old callus cells, the numbers of B chromosomes ranged from one to four in 65.6% of the cells observed. The distribution of B chromosome numbers was associated with the ploidy levels of the normal chromosomes （A chromosomes）. The frequency of the cells with high numbers of B chromosomes （i.e., three or four B chromosomes） in the amphiploid cells with 56 A chromosomes was greater than those in the haploid cells with 28 A chromosomes. Although structural changes in the rye A chromosomes were observed, cytological observation and genomic in situ hybridization demonstrated that the rye B chromosomes were conserved in morphological appearance following tissue culture.     

一个常染色体显性遗传先天性眼外肌 纤维化家系A

为寻找疾病相关基因,通过随访调查、体检、病理检查等手段,发现了一眼外肌纤维化家系4代中有15人患有眼外肌纤维化综合征,主要表现先天性上眼睑下垂、下颌上举、头后仰、双眼固定下转位和被动牵拉试验阳性,眼外肌病理检查结果为肌纤维化和玻璃样变性,所有阳性体征者除眼球运动限制程度有区别外,其他眼部症状基本相同。遗传分析表明,该疾病属常染色体显性遗传。该家系可作为寻找眼外肌纤维化疾病相关基因的宝贵资源。Abstract: To discover novel disease genes, a family with congenital fibrosis of the extraocular muscle was studied by a follow-up investigation, eye examinations and histo-pathological examination. There were fifteen cases suffering from congenital general fibrosis syndrome in four generations. They have congenital blepharoptosis, head tilt, chin lift, primary gaze fixed in a hypo- and exotropic position. The diagnosis is confirmed with positive forced duction testing in the affected eye. Furthermore, fibrosis of the extraocular muscles and hyaline degeneration was confirmed by histo-pathological examination. Except for different levels of restriction of the eyeball movements , other eye symptoms in positive patients are substantially identical. The genetic analysis showed that this disease was caused by autosomal dominant inheritance. The pedigree may be precious resource candidate for discovering disease gene related with congenital fibrosis of the extraocular muscle.     

对水稻第9和第12染色体编号分歧的细胞学考证

在水稻细胞遗传研究中, 对于染色体编号有着较多的争议,这在几条长度较短的染色体上显得尤为突出。为有比较地研究这几条染色体在水稻染色体组中的正确编号,本研究以涉及两条较短染色体相互易位的易位杂合体RT9-12为材料,分析了易位系与普通品种日本晴减数分裂粗线期染色体的形态特征。结果表明,该易位系的易位染色体并非第9和第12染色体,而是第10和第11染色体,从而认为目前国际上统一编号的第9、12染色体,根据染色体的实际长度可能分别为第10、11染色体。 Abstract:Rice chromosomes in mitosis are usually too small to be identified clearly one from others.In recent years,pachytene chromosomes in meiosis have been in vestigated intensively for establishing unified numbering system.However,divergence in numbering system is still existing especially for some short chromosomes such as chromosome 9 and 12.In order to verify these chromosomes,a translocation line RT9-12 and a japonica variety Nipponbare were carefully investigated for all the chromosomes morphologically in late pachytene stage.It was found that the chromosomes involved in translocation were chromosome 10 and 11 in stead of chromosome 9 and 12 as being compared with the karyotype of Nipponbare.So we consider that the chromosome 9 and 12 in the present rice chromosome numbering system could be chromosome 10 and 11 according to their length,arm ratio and the relationship with nucleolus.     

海南省鼻咽癌三个高发家系报告

本文调查了鼻咽癌聚集的10个家系。在3个高发家族中,家系1两代11人中有4 人患鼻咽癌;家系2同代6人中有3人患鼻咽癌;家系3同胞5人中有3人患鼻咽癌。我们从肿瘤流行病学、病理类型及其血缘关系作了分析,认为鼻咽癌具有垂直和水平的家族发生 倾向,支持鼻咽癌有遗传倾向的看法。 Abstract:We studied the genealogy with nasopharyngeal carcinoma(NPC)and found 25 patients (18 males,7 females)with NPC in 10 families,aged from 13 to 60.The bron of the same parents were 12 patients,accounting for 48% among these patients.Both male and female patients were found in five families;the patients in four families were all male;there were all female patients in the only one family;At the sametime,21 patients with NPC were the first kinsfolk in 8 families,accounting for 84%.Besides,we looked into 3 families with high incidence;there were 4 out of 11 family members suffering from NPC in the first genealogy in 2 generations;3 of 6 brons of the same parents were ill with NPC in the third genealogy.Based on the studies of cancer epidemiology,pathology and genealogy,our results suggested that the family incidence of NPC had vertical and horizontal thndency,and that genetic factors played a decisive role in NPC incidence.     

一个并指（趾）缺指（趾）家系的遗传分析

本文报道一个并指（趾）缺指（趾）家系。该家系2代4人患有并指（趾）缺指（趾）,同时伴有掌（跖）骨缺少。经过遗传分析,认为该畸形属常染色体显性遗传。 Abstract:A family with syndactyly and adactylism was reported in this paper.There are four sufferers,suffering from syndactyly and adactylism,with the lack of metacarpus and metatarsus in two generations.According to genetic analysis,this disease is caused by autosomal dominant inheritance.     

三个家猪品种和rob易位群染色体分带多态性的比较

对家猪不同品种及家系间的染色体组型、C-带、Ag-NORs多态性进行的研究表明：杜洛克猪、约克夏猪、长白猪体细胞染色体数2n=38,核型2n=10sm+12m+4st+12t, 而13/17易位纯合子猪（36, rob. 13/17）的体细胞染色体数2n=36,核型2n=10sm+12m+6st+8t; 13/17易位杂合子猪（37,rob. 13/17）的体细胞染色体数目为 2n＝37,核型为2n=10sm+12m+5st+10t。5种家猪的C-带在13～18号染色体上存在大、中、小三种类型, 且呈多态性分布。杜洛克猪、约克夏猪、长白猪、13/17易位纯合子猪、13/17易位杂合子猪的Ag-NORs均数分别为2.05、2.06、2.00、1.99、1.98,说明Ag－NORs在品种、个体及细胞间具有多态性。 Abstract:The present experiment is carried out to make comparative stdy on polymorphism of chromosome Karyotypes, C-band ?and Ag-NORs of different breeds and strains in domestic Pigs. The results showed that the chromosome number of somatic cell in Duroc, Yorkshire and Landrace Pig Was 38 and the karyotype was 2n=10sm+12m+4st+12t. But in heterozygous Rob 13/17(37, rob. 13/17) Pig, the chromosome number of somatic cell was 37 andthe karyotype was 2n=10sm+12m+5st+10t, while in homozygousRob 13/17(36, rob. 13/17) Pig, the somatic cell chromosome number was 36 and the karyotype was 2n=10sm+12m+6st+8t. It was also showed that there were three C-band types in size on chromosome No. 13-18 showing polymorphism in three breeds and two strains of domestic Pigs. The average of Ag-NORs in Duroc, yorkshire,Landrace, homozygous Rob. 13/17 and heterozygous Rob. 13/17 Pig was 2.05, 2.06, 2.00, 1.99 and 1.98, respectively. It is suggested that Ag-NORs have polymorphism among strains, which can be used as a genetic index to analyse relationships among domestic animals with high reliability.     

麻雀核型研究的新发现

本文对分布于牡丹江地区的麻雀（Passer montanus montanus Linnaeus）（指名亚种）进行了核型、C带和G带研究,发现了麻雀同一亚种内具有4种核型,即2n=78（正常）、2n=77、2n=76和2n=78（异常）。经分析比较认为,4种核型中,2n=78（正常）为基础核型,而其他3种核型是在此基础上由微小染色体发生过罗伯逊易位（Robertsonian translocation）形成的。从而为罗伯逊易位在鸟类核型进化中起重要作用这一推测提供了直接的证据。Abstract: The karyotype .C-band and G-band of the tree sparrow (Passer montanus montanus L.) in Mudanjiang area were studied, and 4 karyotypes were discovered, they are 2n=78 (normal), 2n=77,2n=76 and 2n=78(unusual). By analysis and comparison it can be considered that the 2n=78(normal) is a basic karyotype in the 4 karyotypes, and the others are formed by Robertsonina translocation between microchromosomes on this base, thus providing the inference that the Robertsonian translocation plays an important role in karyotype evolution of birds with direct evidence.