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1.
Morphological variation and change of chromosome number in the plantlets of potato (Solanum tuberosum L. cv. Xiao Yie Zi × Duo Zi Bai) regenerated from mesophyll protoplasts have been studied. The normal plantlets from protoplasts were similar to parent plants. Their chromosome numbers were 2n = 48±or 2n= 72 of euploid. The plantlets with distinctive phenotypic variation were likely to be aneuploid with increased chromosome numbers.  相似文献   

2.
云南保存橡胶树部分种质资源干形及分枝变异分析   总被引:2,自引:0,他引:2  
对保存于"农业部景洪橡胶树种质资源圃"的1904份橡胶树81’IRRDB种质资源的主干通直度、主干分杈、侧枝分枝轮、侧枝粗细、侧枝分枝角、侧枝伸展等6个表型性状进行调查和分析。结果表明,云南保存橡胶树种质资源具有丰富的遗传多样性(0.2604~1.6731),多样性指数最高的是主干通直度,达1.6731,其次是主干分杈、侧枝粗细、侧枝分枝轮和侧枝分枝角,最低的是侧枝伸展。6个表型性状的相对分布频率最小值为2.92%~8.05%,最大值为41.26%~93.37%。用UPGMA法聚类,当欧式距离为1.05时,1904份样本被聚为5组,其中最大1组包括98.42%的样本,表明同一性状在每份种质资源间具有很大程度的相似性;用Furthest Neighbor法聚类,在欧式距离为1.45时,1904份样本被聚为7组。2种聚类方法都能将每份种质明显区分出来,表明各性状变异极其丰富。  相似文献   

3.
Mitochondrial genome and functional alterations are related to various diseases including cancer. In all cases, the role of these organelles is associated with defects in oxidative energy metabolism and control of tumor-induced oxidative stress. The present study examines the involvement of mitochondrial DNA in cancer and in particular in breast cancer. Furthermore, since mitochondrial DNA is maternally inherited, hereditary breast cancer has been focused on.  相似文献   

4.
The impact of uterine cervix cancer (UCC) can be greatly reduced by regular vaginal examination and other preventive measures. With this aim, UCC screening programs had been developed and applied for several years in Mexico and elsewhere. One point still to be considered in such preventive programs is the possible circannual pattern in the morbidity or mortality of UCC. With the aim of identifying a possible circannual pattern of variation in the incidence of UCC, we analyzed the monthly totals of positive detected cases of UCC in the state of Nuevo León (Mexico) between 1978 and 1987. For eliminating bias due to the seasonal variation in the number of preventive check-ups, data were first expressed in percentage of tests done in the same month. The least-squares fit of a 1 -year cosine curve to the data reveals a statistically significant circannual pattern (p = 0.013), with a maximum of relative incidence detected in February. Results indicate UCC incidence higher than the yearly average during the winter, with secondary peaks in August and November. This pattern of variation is similar if one considers separately for analysis the relative incidence of type III, IV, or V UCC (relating to cases suggesting, highly suggesting, or concluding a malignant alteration, respectively). For evaluating the cost-effectiveness of the UCC screening campaign providing these data, the monthly totals of screening check-ups done over the same period were also analyzed. Results reveal a statistically significant circannual rhythm (p > 0.001), with a maximum detected in June. This timing seems to be related to the incidence of most common diseases in Mexico, such as giardiasis and salmonellosis, but not to the UCC morbidity rates. Health educational and screening campaigns for prevention of UCC and other major conditions should be timed during the year according to morbidity and mortality statistics, for which a circannual pattern of variation is documented herein.  相似文献   

5.
对108份薏苡属种质资源的22个表型性状进行了多样性分析和分类。结果表明,全部材料涵盖了薏苡属的2个种和4个变种,除了花药色表现一致外,其他9个描述型性状(芽鞘色、叶鞘色、幼苗叶色、柱头色、幼果颜色、果壳色、喙的有无、总苞形状、总苞质地)的多样性指数在0.5519~1.6475之间,12个数值型性状(株高、着粒层、主茎粗、叶长、叶宽、总分蘖数、有效分蘖数、主茎节数、分枝节位、百粒重、粒长、粒宽)的变异系数范围为13.01%~60.09%。相关分析发现,大部分数值型性状间存在显著相关性,而主成分分析将表型性状分为5个主成分,累积贡献率为77.363%。聚类分析将108份资源划分为3个类群,类群Ⅰ主要分布在较高纬度地区,表现为植株矮小、叶片小、节数少和分枝节位低等特点;类群Ⅱ主要分布在中国的长江中下游、西南和南方地区及东南亚的较低纬度地区,表现为植株高度、茎粗、节数及叶片大小等表现中等、分蘖数偏低等特点;类群Ⅲ分布在中国西南地区,主要表现为植株茎秆高大粗壮、叶片大、节数多和分枝节位高、分蘖多、生物量大等特征。大部分材料均表现出比较明显的地域性和不同的表型特征,可以作为薏苡新品种选育和改良的优异亲本材料。  相似文献   

6.
The distribution of capillaries, sinuses and larger vessels was investigated by immunohistology in paraffin sections of 12 adult human spleens using a panel of antibodies. Double staining for CD34 and CD141 (thrombomodulin) revealed that capillary endothelia in the cords of the splenic red pulp and at the surface of follicles were CD34+CD141, while red pulp sinus endothelia had the phenotype CD34CD141+. Only in the direct vicinity of splenic follicles did sinus endothelial cells exhibit both antigens. Thus, splenic sinuses do not replace conventional capillaries, but exist in addition to such vessels. The endothelium in arterioles, venules and larger arteries and veins was uniformly CD34+CD141+. Anti-CD34 and anti-CD141 both additionally reacted with different types of splenic stromal cells. Differential staining of capillaries and sinuses may permit a three-dimensional reconstruction of serial sections to unequivocally delineate the “open” and “closed” splenic circulation in humans.  相似文献   

7.
In the present study we tested the phenotypic profile as well as several immunological responses of peripheral blood mononuclear cells (PBMC) isolated from melanoma patients. These patients underwent chemotherapy with dacarbazine and carboplatin from day 1 to day 22, followed by immunotherapy of low-dose recombinant interleukin-2 and recombinant interferon administered subeutaneously from day 36 to day 75. The PBMC from 14 patients were isolated on day 0 before chemotherapy. on day 36 after chemotherapy and on day 76 after immunotherapy. After chemotherapy, a decrease in CD16+ cells and increase in CD3+ and CD4+ cells correlated with a significant decrease in the generation of lymphokine-activated killer (LAK) activity. After immunotherapy, an increase in CD16+ cells correlated with an increase in the induction of LAK activity. A comparison between responding and non-responding patients revealed statistically significant differences in LAK activity of PBMC and response to concanavalin A following chemotherapy, and in the percentage of CD8+ cells following immunotherapy. Our results point toward the value of continuing such a study on a larger population of cancer patients in order to select the appropriate bioassays for monitoring and predicting the clinical responsiveness to combined therapies.  相似文献   

8.
同工酶与桑品种遗传变异的关系   总被引:1,自引:0,他引:1  
通过以冬芽为材料,对7681桑进行过氧化物酶,细胞色素氧化酶酶谱分析,结果表明7681桑是亲本体细胞融合的真杂种;  相似文献   

9.
ABSTRACT

Background: In 2002, a strong association was highlighted between local melanoma incidence and the number of locally covering main Frequency Modulation (FM) transmitters in Sweden. This study investigated whether an association also exists between melanoma incidence and the average density of main FM transmitters in different European countries. Methods: Twenty-three different European countries were asked to disclose the number of main transmitters used for the FM broadcasting band (87·5–108 MHz) in the respective country. Incidences of melanoma, breast cancer and all cancers together per country were correlated with their respective average density of transmitters per 10,000 km2. Findings: Both melanoma and breast cancer, as well as all cancers together, appear to be significantly associated with the density of main FM broadcasting transmitters in the European countries examined. Interpretation: The findings present strong support to the earlier presented hypothesis that body-resonant broadcasting radiation emitted by horizontally polarized main FM transmitters has an immune-disturbing effect. Funding: This study was financed by internal funds within Hallberg Independent Research only.  相似文献   

10.
11.
Variability contrasts with variation in that variability describes the potential for variation, not simply the expressed variation. The power of studying variability lies in creating a conceptual framework around which the relationship between the genotype and phenotype can be understood. Here, we attempt to demonstrate the importance of phenotypic variability, how it structures variation, and how fundamental developmental processes structure variability. Given the broad scope of this topic, we focus on three widely studied properties of variability: canalization, developmental stability and morphological integration. We have organized the paper to emphasize the importance of differentiating between the theory surrounding these components of phenotypic variability, their measurement and the biological factors surrounding their expression. First, we define these properties of variability, how they relate to each other and to variability as a whole. Second, we summarize the common methods of measurement for canalization, developmental stability and morphological integration and the reasoning behind these methods. Finally, we focus on jaw development as an example of how the basic processes of development affect variability and the resultant variation, with emphasis on how processes at all levels of the organismal hierarchy interact with one another and contribute to phenotypic variability.  相似文献   

12.
The human osteosarcoma cell line Saos-2 is widely used as a model system for human osteoblastic cells, though its phenotypic stability has not been ascertained. We therefore propagated these cells over 100 passages and compared relevant phenotypic properties. In general, higher passage cells exhibited higher proliferation rates and lower specific alkaline phosphatase activities, though mineralization was significantly more pronounced in cultures of late passage cells. Whereas expression of most genes investigated did not vary profoundly, some genes exhibited remarkable differences. Decorin, for instance, that has been discussed as a regulator of proliferation and mineralization, is strongly expressed only in early passage cells, and two receptors for pleiotrophin and midkine exhibited an almost mutually exclusive expression pattern in early and late passage cells, respectively. Our observations indicate that special care is required when results obtained with Saos-2 cells with different culture history are to be compared.  相似文献   

13.
对我国棉花中期库保存的200份不同地理来源的亚洲棉代表性样本进行了表型遗传多样性分析,结果表明,亚洲棉表型多样性丰富,种质间表型性状差异显著或极显著.19个表型性状的Shannon-Wiener多样性指数在0.34 ~2.15间,其大小依次为:衣分>株高>生育期>铃重>果枝始节=子指>叶枝数>短绒色>黄萎病抗性>茎色>...  相似文献   

14.
15.
N. T. Miyashita 《Genetics》1990,125(2):407-419
Restriction map polymorphism in a 13-kb region of the Zw locus in Drosophila melanogaster was investigated for 64 X chromosome lines with seven 6-cutter and ten 4-cutter restriction enzymes. A total of 203 restriction sites were scored, of which 20 were found to be polymorphic. The estimated nucleotide variation for this region for overall data (pi = 0.003 and 0.001, and theta = 0.003 and 0.002, for 4-cutter and 6-cutter studies, respectively) was smaller than that reported for most regions studied in D. melanogaster. It was found that the Slow allozyme has a larger nucleotide variation and haplotype diversity than the Fast allozyme. Results suggest the relatively recent divergence of the Fast allozyme from the Slow allozyme. Glucose 6-phosphate dehydrogenase (G6PD) activity was measured as a phenotype of the Zw locus. A significant difference in G6PD activity between allozymes was detected. The between-line effect was highly significant within the Slow allozyme, but was not significant within the Fast allozyme. Although a direct causative link could not be established, these results suggest an association between the amounts of quantitative and molecular genetic variation at the Zw locus region.  相似文献   

16.
17.
Studies comparing phenotypic variation with neutral genetic variation in modern humans have shown that genetic drift is a main factor of evolutionary diversification among populations. The genetic population history of our closest living relatives, the chimpanzees and bonobos, is now equally well documented, but phenotypic variation among these taxa remains relatively unexplored, and phenotype-genotype correlations are not yet documented. Also, while the adult phenotype is typically used as a reference, it remains to be investigated how phenotype-genotye correlations change during development. Here we address these questions by analyzing phenotypic evolutionary and developmental diversification in the species and subspecies of the genus Pan. Our analyses focus on the morphology of the femoral diaphysis, which represents a functionally constrained element of the locomotor system. Results show that during infancy phenotypic distances between taxa are largely congruent with non-coding (neutral) genotypic distances. Later during ontogeny, however, phenotypic distances deviate from genotypic distances, mainly as an effect of heterochronic shifts between taxon-specific developmental programs. Early phenotypic differences between Pan taxa are thus likely brought about by genetic drift while late differences reflect taxon-specific adaptations.  相似文献   

18.
In Europe, the occurrence of familial melanoma in combination with the occurrence of dysplastic nevi in melanoma patients has been reported by groups from Scotland, France, Italy, and The Netherlands. The major publications of these groups are briefly mentioned and summarized. This report specifically describes nine extensive Dutch pedigrees. Clinical an genetic studies were performed in kindreds among whom three or more individuals with melanoma occurred in at least two consecutive generations. Three hundred sixty-two living persons older than 10 years were screened. The mean number of family members was 60, which makes these pedigrees preeminently suited for genetic studies. Spouses were not included in the study. One hundred eighty individuals were recognized as gene carriers. After correction for bias of ascertainment, we calculated a segregation rate of 0.45, compatible with dominant inheritance. Of the 180 living or alive at the start of the study, 40 had a melanoma, 118 had dysplastic nevi, and 22 were regarded as obligate gene carriers on the basis of their position in the pedigree. The finding of nonpenetrance and reduced penetrance of the characteristic phenotype of the dysplastic nevus syndrome has important consequences for daily practice. When a family is requested to attend the pigmented lesion clinic, all members have an a priori risk of 50% of carrying the gene. Individuals without any abnormalities form the majority, and cases of nonpenetrance and low penetrance are mixed in with the seemingly normal cases. The consequence for our research group was to follow all family members until it is possible to distinguish definitely gene carriers from normal family members. Other malignancies occurred at an increased rate among these families. In two families, the occurrence of several kinds of cancer was obvious. Twenty-four instances of nonmelanoma cancer were found, among which were seven cases of pancreatic carcinoma  相似文献   

19.
Fifty pineapple buds (cv. Red Spanish Pinar, donor) were collected from field-grown plants and cultured in vitro. Forty-three young pineapple shoots were obtained after 42 d of implantation. Shoots were micropropagated for 168 d to produce 24,768 shoots. Three hundred young leaves were randomly selected as explants for callus formation. Calli proliferated for 4 months. Five hundred calli were randomly selected and transferred to the plantlet regeneration medium. Four hundred twenty-seven in vitro-plantlets were obtained and later hardened ex vitro. Then, 387 plantlets were transferred to the field environment and asexually propagated for two generations (30 months). Only two phenotype variants were identified: P3R5 and Dwarf. A more detailed study was carried out to compare these two variants with the donor plant. The variant P3R5 showed differences in the number of slips and suckers, and in the presence of thorns in the leaves and in the fruit crowns. The somaclonal variant Dwarf, was different from the donor plant in regard with the plant height; the peduncle diameter; the number of shoots, slips and suckers; the fruit mass with crown; the number of eyes in the fruit; the fruit height and diameter; the leaf color; the plant architecture; the length of plant generation cycle; and the fruit color and shape. Both somaclonal variants showed different AFLP banding patterns in comparison with the donor cultivar.  相似文献   

20.
Deedu (DU) Mongolians, who migrated from the Mongolian steppes to the Qinghai-Tibetan Plateau approximately 500 years ago, are challenged by environmental conditions similar to native Tibetan highlanders. Identification of adaptive genetic factors in this population could provide insight into coordinated physiological responses to this environment. Here we examine genomic and phenotypic variation in this unique population and present the first complete analysis of a Mongolian whole-genome sequence. High-density SNP array data demonstrate that DU Mongolians share genetic ancestry with other Mongolian as well as Tibetan populations, specifically in genomic regions related with adaptation to high altitude. Several selection candidate genes identified in DU Mongolians are shared with other Asian groups (e.g., EDAR), neighboring Tibetan populations (including high-altitude candidates EPAS1, PKLR, and CYP2E1), as well as genes previously hypothesized to be associated with metabolic adaptation (e.g., PPARG). Hemoglobin concentration, a trait associated with high-altitude adaptation in Tibetans, is at an intermediate level in DU Mongolians compared to Tibetans and Han Chinese at comparable altitude. Whole-genome sequence from a DU Mongolian (Tianjiao1) shows that about 2% of the genomic variants, including more than 300 protein-coding changes, are specific to this individual. Our analyses of DU Mongolians and the first Mongolian genome provide valuable insight into genetic adaptation to extreme environments.  相似文献   

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