首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Despite all the papers on the classification of dermatoglyphic features, there is no definitive in sight yet. With this work we intend to contribute to adapt the subclassification of spiral monocentric whorls to their biologic nature. The results in this work show that clockwise whorls on the right hand match counter-clockwise ones on the left, and counter-clockwise spirals on the right are joined together with clockwise on the left. We propose the building of two new subclasses of spiral monocentric whorls to replace the traditional ones in order to conserve the bilateral identification of these pattern types.  相似文献   

2.
It was stated by Birdsong and Rashad (1972) that the child of birth order number six of Korean families has significantly more true whorls on the finger tips than older brothers and sisters. To verify this assertion we studied a sample of all members of 43 normal German families with 5 or more legitimate children. The findings of the epidermal finger pattern types and those of the toe patterns were analysed. Results indicate a different conclusion regarding the number of digital whorls which were not increased statistically with increasing number of sibs. The number of whorls were randomly distributed within the heritable range of variability of the particular family. It appears of importance that, due to our analyses, the value of information of the characteristic "number of whorls" is not reduced and does not require a specific consideration regarding birth order. Furthermore, it can be stated preliminarly that there is no hint pointing to an influence of the maternal age on the number of whorls in their offspring.  相似文献   

3.
Genetic interactions among floral homeotic genes of Arabidopsis.   总被引:79,自引:0,他引:79  
We describe allelic series for three loci, mutations in which result in homeotic conversions in two adjacent whorls in the Arabidopsis thaliana flower. Both the structure of the mature flower and its development from the initial primordium are described by scanning electron microscopy. New mutations at the APETALA2 locus, ap2-2, ap2-8 and ap2-9, cause homeotic conversions in the outer two whorls: sepals to carpels (or leaves) and petals to stamens. Two new mutations of PISTILLATA, pi-2 and pi-3, cause second and third whorl organs to differentiate incorrectly. Homeotic conversions are petals to sepals and stamens to carpels, a pattern similar to that previously described for the apetala3-1 mutation. The AGAMOUS mutations, ag-2 and ag-3, affect the third and fourth whorls and cause petals to develop instead of stamens and another flower to arise in place of the gynoecium. In addition to homeotic changes, mutations at the APETALA2, APETALA3 and PISTILLATA loci may lead to reduced numbers of organs, or even their absence, in specific whorls. The bud and flower phenotypes of doubly and triply mutant strains, constructed with these and previously described alleles, are also described. Based on these results, a model is proposed that suggests that the products of these homeotic genes are each active in fields occupying two adjacent whorls, AP2 in the two outer whorls, PI and AP3 in whorls two and three, and AG in the two inner whorls. In combination, therefore, the gene products in these three concentric, overlapping fields specify the four types of organs in the wild-type flower. Further, the phenotypes of multiple mutant lines indicate that the wild-type products of the AGAMOUS and APETALA2 genes interact antagonistically. AP2 seems to keep the AG gene inactive in the two outer whorls while the converse is likely in the two inner whorls. This field model successfully predicts the phenotypes of all the singly, doubly and triply mutant flowers described.  相似文献   

4.
Fingers pattern types of a sample of 834 unrelated individuals (353 males and 481 females) from the Biscaian Basque valleys of Uribe, Gernika, Markina, Arratia and Durango were subjected to correspondence analysis. The results show that there are different local subpopulations with regard to these dermatoglyphic traits. The importance of whorls in the separation of these populations is observed. Isolation may have been the factor differentiating between the valleys.  相似文献   

5.
Analysis of the fingerprints of 571 members of the Habbanite isolate suggest inherited patterns and pattern sequences. A genetic theory has been developed; it assumes that the basic fingerprint pattern sequence is all ulnar loops and that a variety of genes cause deviations from this pattern sequence. Genes that have been proposed include: (1) a semidominant gene for whorls on the thumbs (one homozygote has whorls on both thumbs, the other has ulnar loops on both thumbs and the heterozygote usually has two ulnar loops or one ulnar loop and one whorl); (2) a semidominant gene for whorls on the ring fingers which acts like the gene for whorls on the thumbs; (3) a dominant gene for arches on the thumbs and often on other fingers; (4) one or more dominant genes for arches on the fingers; (5) a dominant gene for whorls on all fingers except for an ulnar loop on the middle finger; (6) a dominant gene for radial loops on the index fingers, frequently associated with an arch on the middle fingers; and (7) a recessive gene for radial loops on the ring and little fingers. These genes may act independently or may show epistasis.  相似文献   

6.
Mutations in the AGAMOUS (AG) gene cause transformations in two adjacent whorls of the Arabidopsis flower. Petals develop in the third floral whorl rather than the normal stamens, and the cells that would normally develop into the fourth whorl gynoecium behave as if they constituted an ag flower primordium. Early in flower development, AG RNA is evenly distributed throughout third and fourth whorl organ primordia but is not present in the organ primordia of whorls one and two. In contrast to the early expression pattern, later in flower development, AG RNA is restricted to specific cell types within the stamens and carpels as cellular differentiation occurs in those organs. Ectopic AG expression patterns in flowers mutant for the floral homeotic gene APETELA2 (AP2), which regulates early AG expression, suggest that the late AG expression is not directly dependent on AP2 activity.  相似文献   

7.
The adult Easter Island population was fingerprinted in 1965 as part of an overall study of their human biology. Major findings of the dermatoglyphic analysis are as follows. Digit and bimanuar percentages of patterns (arches, loops, and whorls) were similar to those observed in Europeans. However, in terms of total pattern type distributions, the Islanders had many more whorls and a correspondingly much higher Pattern Intensity Index than those found in European groups. This difference was even present, although in lesser magnitude, in Easter Islanders known to be admixed with Europeans. Corresponding to a high occurrence of whorls, Mean Total Ridge Count (TRC) was also notably high. An association between TRC as a measure of pattern size and incidence of patterns was clearly evident in several groups available for comparison.  相似文献   

8.
Dermatoglyphic studies were carried out on 800 Japanese subjects. Digital dermal pattern types were classified into true whorls, double loops, ulnar loops, radial loops and arches. Both total and absolute ridge count were recorded. Subjects with hypertension, angina pectoris and myocardial infarction were compared with the remaining group of others who had not yet developed any of these disorders. Individuals with myocardial infarction had a significantly higher frequency of true whorls and a correspondingly lower frequency of ulnar loops than the control group. Total and absolute ridge counts were also significantly higher in myocardial infarction. Individuals with hypertension and angina pectoris were not significantly different in most dermatoglyphic traits from the controls. These observations suggest that antenatal factors may contribute to the etiology of myocardial infarction in man.  相似文献   

9.
本文报告了210例糖尿病患者皮纹的11个参数,与对照组相比,各型男患者的足底(足母)趾球区纹型中,三角斗形纹均显著增多;NIDDM型男女患者atd角显著变小;NIDDM型女患者通贯手出现率显著增高;NIDDM型女患者主线C走向I_3的百分率显著增高;各型女患者的指纹中斗形纹出现率显著增高,而尺箕著减少。  相似文献   

10.
In dermatoglyphic methodology the system of gross classification of digital pattern types needs modifications. More attention should be focussed on the study of minute morphological variations among pattern types in order to understand fully the genetic mechanisms involved in pattern variations. A systematic classification to record many of the morphological peculiarities is lacking. This paper proposes a classification and methods of identification of the direction of the course of the ridges inside the pattern area of true whorls. In all, nine ridge course types are identified, named and described. Data analysed on the basis of the above methods and classification reveal significant bilateral differences for clockwise and counter-clockwise types of ridge directions. Mode of inheritance, bisexual differences, etc., of the polymorphic course of these ridges should be studied. Its usefulness in the field of personal identification, population genetics and medicine should also be evaluated.  相似文献   

11.
Studies of gastropod shell growth at the level of fine growth layers are scarce, because coiling of gastropod shells hinders the observation of continuous growth series spanning across whorls. We propose here a new method to obtain continuous growth patterns of gastropod shells over whorls with Terebralia palustris (L.) as an example. Comparison of vertical and horizontal sections of the shell of this species reveals that growth patterns can be observed continuously for several whorls on the vertical section of the columella. In addition, an obvious tidal growth pattern preserved in this species enables us to trace its growth with a precision of 12.4 h and indicates that it takes about two years for a shell to grow from 3 cm to 9.5 cm in height and add 5 complete whorls.  相似文献   

12.
利用扫描电镜观察了青城细辛(Asarum splendens)的花器官发生过程。青城细辛的花器官为轮状结构,向心发生,依次为两轮3基数的花被原基,两轮6基数的雄蕊原基和一轮6基数的心皮原基。两轮花被原基互生,只有外轮(先发生的一轮)花被原基完全发育,而内轮(后发生的一轮)花被原基在发育过程中逐渐退化。两轮雄蕊原基为离心发生:位于内侧的一轮雄蕊原基先发生,每两个原基正对第一轮发生的花被原基,外侧的一轮雄蕊原基后发生,与内轮雄蕊原基互生。心皮与内侧的一轮雄蕊互生。  相似文献   

13.
A horizon in the late Visean Ruddle Shale from Arkansas contains the oldest well-preserved gastropod protoconchs known from the Americas. The gastropod fauna consists of a diverse larval shell assemblage and a low diversity assemblage of juvenile gastropods that probably had a benthic life habit. Gastropod larval shells are always isolated, i.e. the gastropods did not complete their life cycle (no metamorphosis) and were unable to become benthic. This was caused by unfavorable environmental conditions on the soft muddy bottom that was probably due to anaerobic to exaerobic conditions. The absence or scarcity of bioturbation caused by invertebrate detritus or sediment feeders in both shale and concretions (formed before compaction) favored preservation of the delicate larval shells. The lack or scarcity of infauna and bioturbation as well as the low diversity of the presumed benthos supports an interpretation of a quasi-anaerobic to exaerobic benthic environment. The superbly preserved larval shells demonstrate that there are more caenogastropod clades present in the late Palaeozoic than suggested previously. Some larval shell types have an openly coiled first whorl followed by a planktotrophic larval shell; openly coiled initial whorls are unknown from modern caenogastropods. The vetigastropods have a smooth protoconch of two whorls clearly demarked from the following whorls - a pattern unknown in modern vetigastropods which have a protoconch of less than one whorl and build no larval shell during their planktonic stage. This could indicate a link between Palaeozoic vetigastropods and the caenogastropods.  相似文献   

14.
重瓣紫蓝大岩桐组培苗的花同源异型现象(简报)   总被引:1,自引:0,他引:1  
Six types of floral homeotic variants of in vitro seedlings were observed in doubleflower sinningia. Type I, red and green mosaic petals exist in the outermost whorl of petal-whorls, 2.38%. Type II, the outermost whorl of petal-whorls exhibit green petals with thin yellow edge, 25.0%. Type III, green petals exist in the innermost side of normal red petal whorls, 1.78%. Type IV, multiple whorls of green petals exist in the inner side of normal sepals, no stamen and carpel, 1.67%. Type V, it exhibits duplicated whorls of sepals in the outermost, 7.14%. Type VI, it exists multiple whorls of green sepals, no petal, stamen and carpel, 0.12%. The total percentage of all types of floral homeotic variants is up to 38.1%. The distribution of nodal site of homeotic flowers were analyzed, and the results showed that the homeotic flower occurred mainly at the fourth and fifth nodes.  相似文献   

15.
In this paper we study merosity in the genus Urospatha within the framework of a resolved phylogeny of the Araceae. We analyse how a transition from dimerous or tetramerous merosity to pentamerous or hexamerous merosity can occur developmentally in the Lasioideae. In Urospatha, initiation of floral primordia along the inflorescence is acropetal, while development of flowers is basipetal. This indicates the presence of two distinct phases in the development of the Urospatha inflorescence. The first phase corresponds to initiation of flowers and establishment of the phyllotactic pattern, and the second phase to differentiation of floral organs. Urospatha is characterized by the presence of trimerous, tetramerous, pentamerous and rarely hexamerous flowers. In all types of flowers, the stamens are closely associated and opposite to the tepals. Pentamerous flowers are formed by addition of a sector comprising a stamen and tepal. Likewise, in the case of hexamerous flowers, two sectors are added. In the Lasioideae, the increase in the number of tepals and stamens is linked with two developmental processes that have appeared independently in the subfamily: (1) addition of one or two stamen?Cpetal sectors (Anaphyllopsis and Urospatha), and (2) independent increase in the number of tepals and stamens on whorls, more or less organized and inserted in alternate position (Dracontium). Tetramerous whorls as they occur in basal Lasioideae would be homologous to two dimerous whorls from an evolutionary point of view.  相似文献   

16.
I analyzed the finger prints of 59 male and 48 female unrelated Bengalis in a rehabilitation camp of Dacca, Bangladesh. The most common pattern type in the Bengalis was the ulnar loop (53%), then whorls (40%); arches (5%) and radial loops (2%) were the least common. Radial loops occurred most frequently on the index fingers. I have shown the arch/whorl, whorl/loop, and pattern intensity indices, and I have presented ridge counts by individual digits and by total digital ridge count. Digital dermatoglyphics in the male Bangladeshis were similar to previous findings in male Brahmins of Bengal. However, there were more whorls and arches, fewer loops, and a higher mean total digital ridge count in the female Bangladeshis than in female Brahmins.  相似文献   

17.
青城细辛的花器官发生   总被引:1,自引:0,他引:1  
利用扫描电镜观察了青城细辛(Asarum splendens)的花器官发生过程。青城细辛的花器官为轮状结构,向心发生,依次为两轮3基数的花被原基,两轮6基数的雄蕊原基和一轮6基数的心皮原基。两轮花被原基互生,只有外轮(先发生的一轮)花被原基完全发育,而内轮(后发生的一轮)花被原基在发育过程中逐渐退化。两轮雄蕊原基为离心发生:位于内侧的一轮雄蕊原基先发生,每两个原基正对第一轮发生的花被原基,外侧的一轮雄蕊原基后发生,与内轮雄蕊原基互生。心皮与内侧的一轮雄蕊互生。  相似文献   

18.
Studies on the tibiotarsal chaetotaxy of Collembola   总被引:1,自引:0,他引:1  
Abstract. A system of identifying and homologizing the tibiotarsal setae of Collembola by means of letters and numerals is described. These setae are arranged in a series of whorls, each whorl consisting of up to seven setae. The whorls are identified by letters (A, B, etc.), whorl A being the most distal. The setae are numbered from the medio-dorsal surface and over the anterior face, that is, clockwise for left legs but anticlockwise for right legs. The setal pattern appears to be constatn within some genera, and may be of phylogenetic significance.  相似文献   

19.
Abscission of flowers in Lupinus luteus L. (var. Weiko II) withoutgrowth of ovaries is followed by abscission of small pods (15–20mm. long). Normally flower abscission is much more pronouncedthan pod abscission. Abscission was delayed on plants from which laterals or theirterminal and axifliary buds were removed. Flower abscissionwas not affected, but pod abscission increased as a result ofdefoliation. When flowers at the base of the main inflorescence were replacedby auxins and anti-auxins flower abscission was induced in eitheran auxin pattern in which most of the flowers near the siteof application dropped, and pods developed on the apical whorls,or an anti-auxin pattern in which pods developed on basal whorlsnear the site of application but not higher up. The anti-auxinpattern was similar to the pattern of abscission normally inducedby developing pods on basal whorls. -Naphthylacetic acid (NAA) was much more effective in inducingabscission than ß-indolylacetic acid (IAA). 2:3:5-triiodobenzoicacid (TIBA), NAA, and IAA applied in mixtures at various concentrationsacted mainly antagonistically, i.e. the abscission-inducingeffect of NAA and LAA was depressed in basal whorls, and inapical whorls the effect of TIBA was less prevalent. Consequentlythe effect of the mixtures on the total number of pods was aboutequal to that of the most active component by itself. All growth substances seemed to move much more efficiently inacropetal direction than in basipetal direction in the flowerstalk. Transport in lateral direction was very limited. The effect of growth substances applied on laterals was enhancedby defoliating the main 8tem. The influence of assimilates on flower and pod abscission andtransport of growth substances is discussed.  相似文献   

20.
Dermatoglyphic traits were studied in a sample of 834 subjects selected from a cohort of some 8,000 living Japanese men, under a long-term study of heart disease in Hawaii. All of them were born between 1900 and 1919. Among them, 100 subjects had had positive diagnosis of myocardial infarction (MI). The present study included comparisons between the MI patients and the remaining group of all digital dermal pattern types and ridge counts by digit, by hand, and by individual. The MI patients had significantly higher frequency of true whorls, double loops and less ulnar loops and tented arches. Total and absolute ridge counts were significantly higher (less than 0.05) in all digits in favor of the MI patients. Similar trends were observed in analyses by digit and by hand. These observations suggest an antenatal origin of certain types of coronary disease.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号