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本文通过对半夏属Pinellia 5个种10个群体的染色体计数和珠芽数量统计，首次报道了5个染色体数目，同时发现珠芽的发生与染色体基数及多倍化程度有关：x=13的类群无珠芽，而x=9的有珠芽；在有珠芽的半夏P．ternata(Thunb．)Breit．中，平均每叶珠芽数随倍性的提高而增大。半夏是一个多倍体复合种，起源于无珠芽、染色体基数为x=7～9的二倍体祖先，可能是在该属的早期进化中由鹞落坪半夏P.yaoluopingensis X．H．Guo et X．L.Liu的x=13经非整倍性跌落而成，在发生上比鹞落坪半夏进化。 相似文献
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目的了解高原地区藏族肺癌的临床特点和规律,为肺癌的诊治提供参考。方法回顾分析了2008年～2012年自治区人民医院收治的48例藏族肺癌患者的临床资料,采用SPSS18、0统计软件进行统计分析。结果48例藏族肺癌患者的发病年龄平均为58．98岁,男女比例为2．43：1;其中有33例有吸烟史,临床主要症状有咳嗽（44例,91．67％）、痰中带血（27例,56．25％）、胸痛（26例,54．17％）等,鳞癌21例（44．68％）,腺癌7例（14．89％）,小细胞肺癌15例（31．91％）,大细胞癌1例（2．13％）和其他类型肿瘤3例（6．38％）,男性以鳞癌为多（20例,60．61％）,女性以腺癌为多（7例,509／6）。I期和II期7例（14．9％）,Ⅲa期6例（12．77％）,Ⅲb期7例（14．89％）,IV期27例（57．44％）。结论藏族肺癌发病年龄集中在55～65岁,以男性为多,临床表现无特异性,病理类型主要以鳞癌和小细胞癌为主,吸烟为导致藏族人群肺癌发生的主要原因之一。 相似文献
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专家简介:方敏,女,中国科学院微生物研究所,研究员,自然杀伤细胞研究组组长,中国科学院遗传与发育生物学研究所分子免疫遗传学专业,博士,美国福克斯肿瘤研究中心,博士后,专长于利用自然杀伤细胞(NK细胞)对抗传染病、肿瘤等研究,并在此领域有多项重大发现,首次发现NK细胞功能随小鼠年龄的增长而下降并直接导致小鼠丧失抵抗病毒的能力发现NK细胞活化受体CD94-NKG2E识别并特异性杀伤鼠痘病毒感染的细胞以控制病毒感染, 相似文献
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石应江 《中国科技期刊研究》2003,14(1):79-81
为了解中华医学会系列杂志的重点号刊出情况，探讨对重点号的认识和编辑方法，对17种中华医学会系列杂志2001年的重点号刊出情况进行了统计分析。发现中华医学会系列杂志中有1种半月刊组织了19期重点号，8种月刊平均组织了8．1期重点号，7种双月刊平均组织了5．3期重点号，1种季刊组织了2期重点号；4种期刊重点号数占同年总期数的比例为100．0％；4种期刊为80．0％以上，8种期刊为50．0％－79．9％，只有1种期刊低于50．0％。每期与重点号相关文献数占刊出文章总数的比例，3种期刊低于10．0％，11种期刊为 相似文献
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美充耳氏息室是发生在小肠的先天性畸形，多数人可终生无症状，约25％的美克耳氏患室可发生临床症状和合并症。我院1978～1996年经手术证实54例，就其诊断治疗进行总结分析。1临床资料本组男40例，女14例，年令10～55岁，平均27岁，其中因肠梗阻就诊25例（4．3％），穿孔20例（37％），急性炎症6例（1．1％），出血2例（3．7％），1例在胃切除时发现。想室部位距回盲部最近7cm，最远145cm，平均50cm，想室直径0．5～7．5cm，平均2．3cm，憩室长度3～20cm，平均5.5cm。本组54例全部行手术切除，单纯憩室切除35例，憩室埋入缝合10例，憩室颈部… 相似文献
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中国特有的露蕊乌头亚属及铁破锣的染色体研究 总被引：3，自引：0，他引：3
商效民 《中国科学院研究生院学报》1985,23(4):270-274
The paper reports chromosomal number and chromosomal morphologies of
annual Aconitum gymnandrum endemic to China and Beesia calthifolia for the first
time. Of the two spcies, chromosome number is same (X=8, 2n=16) and chromosome
average lengths are 6.17μ , 10.73μ respectively. The longest chromosome 1, the short
chromosomes 3-5, 7 and the shortest chromosome 8 are metacentrical (m), the chro-
mosomes 2, 6 are submetacentrical (sm), and the pairs 4, 5, 8 have satellites in the
karyotype of A. gymnandrum. In B. calthifolia, all of the chromosome 1-5 are the
long m, the chromosomes 6, 8 are the short sm and the 7 is telocentrical (t). The pairs
3, 4, 6 have satellites.
According to the comparison of karyotypes of three subgenera—subgen. Para-
conitum, subgen. Aconitum and subgen. Gymnaconitum in Aconitum, the evolution trend
of chromosomes is further discussed.
Finally, the relationship between Aconitum and Beesia is also discussed in thispaper. 相似文献
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本文详细报道了滇蜀豹子花的核型，发现居群中存在两种细胞型，即A型和B型。A型参考核型为2n = 24＝2m(2SAT)+2sm+8st(4SAT)+12t(2SAT)，其第3号两条同源染色体长臂均无居间随体：B型参考核型为2n=24＝2m(2SAT)+2sm+8st(2SAT)+12t(3SAT)+0—1b，其第3号一条同源染色体长臂紧靠着丝点处有一大而明显的居间随体，而另一条同源染色体则无，构成明显的3号染色体的结构杂合性。统计表明，居群中二者的比例近似为1A；2B。研究还发现了大量的体细胞染色体结构变异核型，表明滇蜀豹子花核型尚未趋于稳定，还处于强烈分化之中，高频率的体细胞染色体结构变异是其种内分化不可忽视的一种进化要素。 相似文献
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濒危植物巴东木莲花粉母细胞减数分裂观察 总被引：1，自引：0，他引：1
对巴东木莲Manglietia patungensis及其近缘种乳源木莲M. yuyuanensis的花粉母细胞减数分裂过程的基本特征进行了比较研究。乳源木莲与巴东木莲的染色体数目和核型相同,但不经任何人为因素诱导,它们之间在减数分裂过程中的染色体行为上有明显差异。(1)巴东木莲减数分裂中期I构型为0.30IV+18.33II+0.15I,与乳源木莲构型19II不同,巴东木莲可能存在同臂内倒位杂合子,染色体结构存在一定的杂合性。(2)后期I和后期II染色体行为异常现象发生频率明显不同。以后期II为例,乳源木莲减数分裂相中有迟滞染色体的细胞占8.8%,迟滞染色体不超过2个;巴东木莲有迟滞染色体等异常现象的细胞占29.2%,迟滞染色体最高达11个,还出现染色体碎裂成断片现象。巴东木莲减数分裂过程中染色体组表现出染色体结构杂合变异和迟滞染色体与染色体的断裂频率很高的异常现象在一定程度上可能影响了雄配子体的发育。 相似文献
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BackgroundFragrance is one of the most important quality traits in rice, and the phenotype is attributed to the loss-of-function betaine aldehyde dehydrogenase (BADH2) gene. At least 12 allelic variations of BADH2 have been identified, and some of these have been applied to rice fragrance breeding using traditional molecular markers and Sanger sequencing techniques. However, these traditional methods have several limitations, such as being very expensive, imprecise, inefficient, and having security issues. Thus, a new molecular marker technology must be developed to improve rice fragrance breeding.ResultsIn this study, more than 95% of the cultivated fragrant rice varieties belonged to a 7-bp deletion in exon 2 (badh2-E2) or an 8-bp deletion and 3-bp variation in exon 7 (badh2-E7). Both allelic variations resulted in the loss of function of the badh2 gene. We developed two novel SNP molecular markers, SNP_badh2-E2 and SNP_badh2-E7, related to the alleles. Their genotype and phenotype were highly cosegregated in the natural variation of rice accessions, with 160 of the 164 fragrant rice varieties detected with the two markers. These markers cosegregated with the fragrance phenotype in the F2 population.ConclusionsTwo functional SNP molecular markers of badh2-E2 and badh2-E7 allelic variations were developed. These functional SNP molecular markers can be used for genotype and genetic improvement of rice fragrance through marker-assisted selection and will significantly improve the efficiency of fragrant rice breeding and promote commercial molecular breeding of rice in the future.How to cite: Li W, Zeng X, Li S, et al. Development and application of two novel functional molecular markers of BADH2 in rice. Electron J Biotechnol 2020;46. https://doi.org/10.1016/j.ejbt.2020.04.004. 相似文献
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Karyotype analysis for the species Reineckia carnea (Andr.) Kunth of the mo-
notypic genus Reineckia Kunth is given for the first time. The number of chromosomes in
root-tip cell was found to be 38, which is in accord with those reported by most of the pre-
vious authors[5,7,8,9,11,12,]. The somatic complement shows a slight variation in size, i.e., the 2,
3, 5, 6, 7th pairs of the chromosomes have submedian constrictions, while the other pairs
have median centromeres. The karyotype is therefore a rather symmetrical one, and accor-
ding to the chromosomal terminology defined by Levan et al[4], the karyotype formula of
the species is 2n=38=28 m+10 sm. In spite of the presence of two nucleoli in the te-
lophase as observed by the authors and Noguchi[8] as well, the two corresponding Sat-chro-
mosomes have not been found. Photomicrograph of the chromosome complement and idiog-
ram are given in Fig. 1 and 2 respectively. 相似文献
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为探讨rDNA在重楼属Paris L.中的分布规律，利用荧光原位杂交（FISH）对4种重楼属植物
的18-26S rDNA进行了定位。所有植物均为二倍体，基因组由A、B、C、D和
E5条染色体构成。（1）滇重楼P.polyphylla var.yunnanensis:2n=10=6m+4t，C和D染色体的
短臂上各有1个18-26S rDNA位点;（2）长柱重楼P.forrestii:2n=10=6m+4t，B染色体的长臂
、C和D染色体的短臂上各有1个位点;（3）五指莲P.axialis:2n=10=6m（2sat）+4t（2sat）
+1-2B，C和D染色体的短臂上各有1个位点;在有1个B染色体的细胞中，B染色体没有信号点，
而有2个B染色体的细胞中，只有1个B染色体上有信号点，表明B染色体上有基因存在且其分裂
不均等;（4）大理重楼P.daliensis:2n=10=4m+2sm+2st+2t，C染色体的短臂上有1个位点。1
8-26S rDNA位点不仅出现在染色体的次缢痕上，也出现在非次缢痕位点。另外，4个种中C染
色体短臂末端均有18-26S rDNA。 相似文献
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Sujatha Baskaran Vani Brahmachari 《Indian journal of clinical biochemistry : IJCB》2000,15(1):145-157
The first report of X-linked mental retardation correlated with the presence of marker chromosome came in 1940. It was in 1990 that the molecular basis of fragile X syndrome was deciphered. This elucidation marked the discovery of a novel process of mutation designated as dynamic mutations, resulting in the expansion of a triplet repeat sequence within the human genome. Subsequently several human genetic disorders involving triplet repeat expansion have been discovered. Almost all the disorders are known to affect the nervous system and/or the brain. This review presents an overview of fragile sites in the genome and the molecular genetics of fragile X syndrome. 相似文献
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国产十种乌头的染色体研究 总被引：1，自引：0，他引：1
本文描述了我国产毛茛科乌头属的10个种的染色体数目和形态。 根据该属染色体基 数为8(x＝8)，可将这些种归为二倍体、四倍体、六倍体和八倍体种。 10种乌头的染色体在数目、大小、结构上表现出相关性。其中具根状茎而多年生的种多为二倍体，染色体形态较大，第3-7号多为近端着丝点(st)染色体, 具块茎而二年生的种多为多倍体，染色体形态较小，第3-7号多为近中着丝点(sm)染色体。染色体演化方向可能是二倍体→多倍体、大→ 小、st→sm。这进一步证明根状茎种较块茎种原始。根据染色体数目和形态，又可将这些种的染色体分为两类。这进一步支持了目前分类学上的牛扁亚属和乌头亚属的划分。本文还讨论了这些种的有关分类问题。 相似文献
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Leonurus japonicus Houtt. [L. heterophyllus Sweet, L. artemisia (Lour.) S. Y.
Hu] is one of the most important traditional Chinese medicines used as a remedy for gynaeco-
logical disease since ancient times. A cytological investigation on the species was carried out
and the materials for chromosomal examination were collected from 26 localities in 20 provi-
noes and autonomous regions of this country. The number of chromosomes in root tip cell of
the species was found to be 20 on the whole (Tab. 1:1), agreeing with those reported by Ma and
al.[2] and probably by Chuang and al.[3] as well.
The genus Leonurus L. is variable in its chromosomes with an aneuploidy of x=9, 10 and
12. The present authors would propose that the primitive basic number of chromosome in the
genus is 9, and thus both 10 and 12 are derived, for: (1) among the 9 species (including 1 sub-
species) heretofore cytologically examined, x=9 occurring in 66.7%, x=10 occurring in 22.2%,
while x=12 occurring only in 11.1%; (2) in generaclosely related to the genus under considera-
tion, such as Panzeria, Galeobdolon and Lamium x=9 being the sole basic number.
But L. japonicus exhibits a mixoploidy of 2n=20 (occurring at the rate of 53.30% of the
total amount of cells examined), 2n=18 (30.70%), and 2n=16 (15.99%) in our work. (Table
1). Since the original basic number of chromosome of the genus is 9 as proposed above, 2n=
20 would be considered as a derived one and the occurrence of 2n=18 probably suggests an
early evolutionary trend of 2n=18→20 of the pecies in question. 相似文献