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1.
We studied 20 electrophoretic loci in two populations ofAteles (Ateles paniscus paniscus andAteles paniscus chamek). We observed intrapopulational variation at the following loci: esterase D, glyoxalase 1, adenosine deaminase (A. p. chamek) and carbonic anhydrase 2 (A. p. paniscus). The two populations share the most frequent alleles at 17 loci, but we noted great differences in glyoxalase 1, adenosine deaminase and phosphoglucomutase 1.A. p. paniscus is monomorphic for theGLO1 *1 allele, which has a frequency of 6% inA. p.chamek. They did not share alleles in relation to the ADA and PGM1 loci. We found a CA2 allele, named hereCA2 *1, which has not been described previously in other neotropical primates (Sampaio et al., 1991a), inA. p. paniscus. The present results suggest that the geographical isolation represented by the Rio Amazonas has lasted long enough to support this level of divergence. These observations taken together with chromosomal findings, led us to endorse the proposal of two distinct species:Ateles paniscus andAteles chamek.  相似文献   

2.
L. Xu  J. Xia  H. Jiang  J. Zhou  H. Li  D. Wang  Q. Pan  Z. Long  C. Fan  H.-X. Deng 《Human genetics》1999,105(1-2):45-50
Hereditary multiple exostoses (EXT; MIM 133700) is an autosomal dominant bone disorder. It is genetically heterogeneous with at least three chromosomal loci: EXT1 on 8q24.1, EXT2 on 11p11, and EXT3 on 19p. EXT1 and EXT2, the two genes responsible for EXT1 and EXT2, respectively, have been cloned. Recently, three other members of the EXT gene family, named the EXT-like genes (EXTL: EXTL1, EXTL2, and EXTL3), have been isolated. EXT1, EXT2, and the three EXTLs are homologous with one another. We have identified the intron-exon boundaries of EXTL1 and EXTL3 and analyzed EXT1, EXT2, EXTL1, and EXTL3, in 36 Chinese families with EXT, to identify underlying disease-related mutations in the Chinese population. Of the 36 families, five and 12 family groups have mutations in EXT1 and EXT2, respectively. No disease-related mutation has been found in either EXTL1 or EXTL2, although one polymorphism has been detected in EXTL1. Of the 15 different mutations (three families share a common mutation in EXT2), 12 are novel. Most of the mutations are either frameshift or nonsense mutations (12/15). These mutations lead directly or indirectly to premature stop codons, and the mutations generate truncated proteins. This finding is consistent with the hypothesis that the development of EXT is mainly attributable to loss of gene function. Missense mutations are rare in our families, but these mutations may reflect some functionally crucial regions of these proteins. EXT1 is the most frequent single cause of EXT in the Caucasian population in Europe and North America. It accounts for about 40% of cases of EXT. Our study of 36 EXT Chinese families has found that EXT1 seems much less common in the Chinese population, although the frequency of the EXT2 mutation is similar in the Caucasian and Chinese populations. Our findings suggest a possibly different genetic spectrum of this disease in different populations. Electronic Publication  相似文献   

3.
In this study the entirep53 complementary DNA has been sequenced in 20 non-small cell lung carcinomas (NSCLC) and the results correlated with chemosensitivity, immunohistochemistry and clinical data. Ten patients had mutations inp53, 8 missense mutations and 2 nonsense mutations. The method discovered two mutations never described previously and two other mutations that have never been described before in connection with NSCLC tumours. Chemosensitivity data, according to a short-term assay (FMCA), indicated that tumours with p53 mutation were more resistant to cisplatin and cyclophosphamide. Immunohistochemical studied demonstrated a 70% concordance between over-expression of p53 protein and mutation inp53. No conclusions or trends could be drawn from the immunohistochemical studies ofBcl-2 andBax.  相似文献   

4.
An RFLP analysis of the chloroplast genetrnK of 32 species of the generaPapaver, Roemeria, Stylomecon, andMeconopsis leads to the following conclusions: (1) AsianMeconopsis consists of two distinct clades and is paraphyletic in relation toPapaver, Roemeria, Stylomecon, and the W EuropeanMeconopsis cambrica. (2) Sister group relationships ofRoemeria toPapaver sect.Argemonidium and ofStylomecon toPapaver californicum are well-supported. (3)Meconopsis cambrica is nested withinPapaver (incl.Roemeria andStylomecon). The consideration of morphology, geographical distribution and ecology leads to the conclusion thatM. cambrica is best regarded as a member ofMeconopsis, and thatPapaver arose polyphyletically from within a paraphyleticMeconopsis in response to Tertiary climatic aridification. — The removal ofM. cambrica from the taxon matrix is discussed. It is concluded that this experiment illuminates the importance of critical taxon sampling, and shows that at least potentially the assessment of taxa as mono-, para-, or polyphyletic may characterize their present status only and need not reflect their phylogenetic history.  相似文献   

5.
Aerobic and anaerobic metabolism during activity in snakes   总被引:2,自引:0,他引:2  
Summary Oxygen consumption and blood lactate concentration in the snakesColuber constrictor, Crotalus viridis, Lichanura roseofusca andMasticophis flagellum and whole body lactate concentration inCrotalus viridis andMasticophis flagellum were determined under standard conditions and after a bout of maximal activity induced by a 5 min period of mechanical stimulation. Observations were made atT b=35°C inColuber, Crotalus, andMasticophis and 32°C inLichanura. Maximal oxygen consumption inColuber andMasticophis was twice that ofCrotalus and 4 x that ofLichanura (Fig. 1). Post-active whole body lactate concentration inMasticophis was twice that ofCrotalus (Fig. 2). Immediately post-active and 30 min post-active blood lactate concentration inColuber andMasticophis was 1.5 x and 3.5 x that ofCrotalus andLichanura, respectively (Fig. 3). These data support conclusions that: (a) maximal energy production by these snakes correlates well with their respective modes of predation and defense, the highly active predatorsColuber andMasticophis being capable of the greatest net energy production during activity; (b)Coluber andMasticophis exhibit aerobic scopes as high or higher than any other comparably sized reptile heretofore investigated; (c) weight specific anaerobic metabolism probably does not decrease with increasing body size in reptiles; (d) anaerobic metabolism provides >50% of net energy production during five minutes of activity in all species examined (Table 1).  相似文献   

6.
Claes Persson 《Brittonia》2003,55(2):176-201
Agouticarpa, a new genus of the informalAlibertia group (Rubiaceae), is described and illustrated. It comprises six species, and occurs from Costa Rica to Bolivia. Three species are here described as new:Agouticarpa grandistipula, A. hirsuta, andA. velutina. Additionally, three new combinations are made:A. curvifolia andA. williamsii (previously inGenipa) andA. isernii (previously inAlibertia). Agouticarpa is characterized by being dioecious, having elliptic to abovate, membranaceous stipules, male flowers in a branched dichasial or thyrse-like inflorescence, a poorly developed cup-shaped calyx, pollen grains with 3–7 apertures, and large globose fruits.  相似文献   

7.
Detailed analyses of karyology and leaf morphology do not support relationships betweenFlacourtiaceae andTiliaceae. In spite of different chromosome numbers,Prockia (2n = 18),Flacourtia (2n = 22) andRawsonia (2n = 22) are very similar in karyomorphology, indicating a certain karyological uniformity withinFlacourtiaceae. Lacistema (2n = ca. 62) appears more isolated. On the other hand, theTiliaceae Grewia (2n = 18) andLuhea (2n = 36) have much in common and differ remarkably from the Flacourtiaceous genera. The salicoid leaf-teeth ofProckia are also found inIdesia, but never inTiliaceae. Epidermis ultrastructure reveals certain relationships betweenProckia andFlacourtia in contrast to the strongly differingGrewia. Idesia has a rare und unique epidermis sculpture. — Basic chromosome numbers and chromosomal evolution within theFlacourtiaceae are discussed.
  相似文献   

8.
Cold-induced mitotic under-condensation of certain chromosome segments is a rare phenomenon in plants. There are about 11 genera of monocotyledons and only 3 of dicotyledons, where species are known to have such cold-sensitive regions (CSRs). The molecular causes of cold-induced undercondensation are not clear, and no consistent cytochemical characteristics of CSRs are known. Recently we have presented a chromosome banding analysis on CSRs and their relation to constitutive heterochromatin inCestrum parqui (Solanaceae), a species of sect.Cestrum. The present study is concerned with a similar analysis inC. strigillatum of sect.Cestrum, and inC. fasciculatum andC. elegans of sect.Habrothamnus. Chromomycin/DAPI fluorescent double staining, sequential C-banding, and sequential silver impregnation were applied. The species differ in detail but are similar qualitatively. Four classes of heterochromatin can be discriminated. (1) CSRs, with banding properties indicating AT-rich constitutive heterochromatin. After cold-treatment CSR heterochromatin can be silver-impregnated from interphase, as chromocentres, to metaphase, as undercondensed segments. CSRs are subject to frequent heteromorphy. (2) Nucleolar organizers. Two pairs were identified in the karyotypes. Banding properties indicate GC-rich heterochromatin. The nucleolar organizing regions are less evident and their silver-reducing capability reduces during metaphase. (3) Non-nucleolar CMA-positively fluorescing bands. These are minute, polymorphic, positively C-stained, and restricted to one or a few sites in the karyotypes. (4) Indifferently fluorescing, positively C-stained bands. They occur on centromeres, some chromosome ends, and clustered over the chromosome arms. They are mostly very delicate and do not resist harsh banding treatments. — The species investigated here andC. parqui resemble each other qualitatively in heterochromatin classes (1), (2), and (3), but differ much in banding properties of class (4). Therefore, heterochromatin characteristics in the genus are not so uniform as the present results inC. strigillatum, C. fasciculatum, andC. elegans appear to show.  相似文献   

9.
Chromosome numbers are polyploid, 2n = 28 inBrunellia comocladiifolia andB. mexicana, and 2n = 46 inCaryocar brasiliense, C. microcarpum andC. villosum. The chromosome are small in both genera, with a length of ca. 1,6-0,4µm. Interphase nuclei correspond to the prochromosomal and the chromocentric type, respectively. This is in conformance with the systematic placement ofBrunelliaceae intoCunoniales, and ofCaryocaraceae intoTheales. Brunellia exhibits affinities to various other orders ofRosidae (andHamamelididae), and is suggested to be primarily apetalous. On a comparative basis, the chromosome numbers found in both families are interpreted as paleopolyploid (4 x and 6 x). This apparently is in correspondence with their rather primitive features, systematic isolation, relatively depauperate status, and evidently great age.  相似文献   

10.
Chromosome studies of four HimalayanTorilis species reveal a remarkable interand intraspecific differentiation of chromosome numbers and karyotypes:T. arvensis (2n = 12),T. leptophylla (2n = 12),T. Stocksiana (2n = 36) andT. japonica (2n = 16). Base numbers inTorilis are x = 6, 8, 9 and 11.  相似文献   

11.
Lectotypes are selected for 10 names inHypericum (Clusiaceae),Elatine (Elatinaceae),Arctostaphylos andVaccinium (Ericaceae),Androsace (Primulaceae), andViola (Violaceae).  相似文献   

12.
Electroreceptive neurons in the posterior branch of the anterior lateral line nerve of three species of electric fish (Gymnotoidei):Sternopygus macrums, Eigenmannia virescens, andApteronotus albifrons, show speciesspecific differences in the filtering of electrical stimuli. All of the tuberous electroreceptor fibers of an individual are tuned to the same frequency: that of the electric organ discharge (EOD) of the species, more specifically, to that of the individual. The fibers inSternopygus are tuned to 50–150 Hz; those inEigenmannia to 250–500 Hz, and those inApteronotus to 800–1,200 Hz (Figs. 3, 5, 8). Two classes of organs inSternopygus andEigenmannia, P and T units, respond to sinusoidal stimuli at the unit's best frequency (BF) with a phase-locked partially-adapting (P), or tonic (sustained) (T) discharge. T-units are more sharply tuned and are more sensitive than P-units. Only one class of organs,P or partially adapting units, have been found inApteronotus and phase-locking is less evident than it is in other species.Nerve section proximal to the recording site does not alter the tuning curves inSternopygus (Fig. 18), but local warming and cooling of the cutaneous receptor site in bothSternopygus andEigenmannia shifts the tuning curve to higher and lower frequencies, respectively (Fig. 17).  相似文献   

13.
Eighteen adult skeletons ofLoris tardigradus lydekkerianus (4 males and 4 females) andNycticebus coucang (6 males and 4 females) have been studied for the asymmetries in the long bones of the limbs and of the clavicles. The bones of the upper extremity are longer in the right inLoris andNycticebus. Asymmetry favours the right side more inLoris than inNycticebus regarding the thigh bone and the total length of the lower extremity. Lorises do not essentially differ from the other primates including man, regarding the asymmetries of the lower extremities as they do in regard to the asymmetries of the upper extremities.Averages of the percentage asymmetries are higher in females than in males. Cases of symmetry are rarer in clavicles (0%) than in the other bones of the upper and lower extremities ofLoris andNycticebus but they do favour radius inNycticebus (45%) alone. There are no significant sex differences in the 2 series in the distribution of the asymmetries.The average of the degrees in which the lengths of the corresponding limb bones are unequal on the 2 sides of the body are approximately the same inLoris (0.78),Hylobatidae (0.70) and the great apes (0.72) with regard to the upper extremities. In the lower extremities, however, these degrees including those in man (0.63) and the macaque (0.61), excepting inHylobatidae (0.86) are practically the same as inNycticebus (0.61) while much higher than those inLoris (0.43).This investigation forms a part of the main research programme based on the anatomical and metrical data, on the Indian Lorises, conducted under the aegis of the Council of Scientific and Industrial Research, New Delhi, during the years 1962–65.This paper was presented before the section of Anthropology and Archaeology of the Indian Science Congress Association at its 54th annual session held at Hyderabad in January 3–9, 1967.  相似文献   

14.
Summary TheWnt family of proto-oncogenes encodes secreted signaling proteins that are required for mouse development. TheDrosophila Wnt homolog, thewingless (Wg) segment polarity gene, mediates a signal transduction pathway in which the downstream elements appear to be conserved through evolution. One such element, thedishevelled gene product, becomes hyperphosphorylated and translocates to the plasma membrane in response to Wg (Yanagawa et al., 1995). We report here that the mouseDishevelle-1 (Dvl-1) andDishevelled-2 genes encode proteins that are differentially localized inWnt-overexpressing PC12 cell lines (PC12/Wnt). WhereasDvl-1 andDvl-2 proteins are limited to the soluble fraction of parental PC12 cells, PC12/Wnt cells display a subset ofDvl-1 protein associated with the membrane andDvl-2 protein with the cytoskeletal fraction. These results suggest a conserved role forDvl inWnt/wg signal transduction.  相似文献   

15.
The biomass production of three common aquatic macrophytes,viz. Azolla pinnata, Eichhornia crassipes andHydrilla verticillata, was high at the prevailing environmental conditions and by the enriched water of River Ganga. The biomass production ofAzolla andEichhornia was positively correlated with the orthophosphate phosphorus and nitrate-nitrogen concentrations of the enriched water. The biomass ofAzolla andHydrilla was positively correlated with the electrical conductivity of the water. The average yield of crude protein was highest in Azolla (8,520 kg.ha–1.yr–1), and somewhat lower inEichhornia (6,520 kg.ha–1.yr–1). The annual biogas production was highest inEichhornia (44,381 litres), and somewhat lower inAzolla (17,186 litres).  相似文献   

16.
Esters are formed by the condensation of acids with alcohols. The esters isoamyl acetate and butyl butyrate are used for food and beverage flavorings. Alcohol acetyltransferase is one enzyme responsible for the production of esters from acetyl-CoA and different alcohol substrates. The genes ATF1 and ATF2, encoding alcohol acetyltransferases from the yeast Saccharomyces cerevisiae have been sequenced and characterized. The production of acids and alcohols in mass quantities by the industrially important Clostridium acetobutylicum makes it a potential organism for exploitation of alcohol acetyltransferase activity. This report focuses on the heterologous expression of the alcohol acetyltransferases in Escherichia coli and C. acetobutylicum. ATF1 and ATF2 were cloned and expressed in E. coli and ATF2 was expressed in C. acetobutylicum. Isoamyl acetate production from the substrate isoamyl alcohol in E. coli and C. acetobutylicum cultures was determined by head-space gas analysis. Alcohol acetyltransferase I produced more than twice as much isoamyl acetate as alcohol acetyltransferase II when expressed from a high-copy expression vector. The effect of substrate levels on ester production was explored in the two bacterial hosts to demonstrate the efficacy of utilizing ATF1and ATF2 in bacteria for ester production.  相似文献   

17.
This work examines the cytogeographical distribution, the morphological characters, and the karyotypes of threeCrepis species endemic to Greece (C. sibthorpiana, C. incana, andC. heldreichiana). C. sibthorpiana is diploid (2n = 2x = 8),C. incana is diploid (2n = 2x = 8) and tetraploid (2n = 4x = 16, 17), andC. heldreichiana is always dekaploid (2n = 10x = 40). The Giemsa positive bands, usually pairs of dots, are mainly centromeric inC. incana, while they are terminal inC. sibthorpiana (on the short arm of all chromosomes) and inC. heldreichiana (on both arms of all chromosomes). Intercalary C-bands are scarce and usually variable within karyotypes, individuals, and species. The most variable karyotype both in Feulgen and Giemsa preparations is that ofC. incana, in which also supernumerary chromosomes were observed, which are polysomic to standard set members. On the basis of morphological and karyological data the evolutionary relationships among the threeCrepis taxa are discussed.  相似文献   

18.
The freeze-dried (extracted and non-extracted) biomass of 15 microalgal species grown in axenic mass culture and belonging to the Cyanobacteria, Chloro-, Eustigmato-, Phaeo-, Rhodo- and Tribophyceae were investigated for their ability to adsorb cadmium (Cd) ions from aqueous solutions. For comparison, other standard adsorbing materials (activated carbon, silica gel, siliceous earth) were included in the studies. The biomass of 11 microalgae exhibited a higher Cd adsorption than the standard materials. Extraction of the algal biomass increased the Cd adsorption capability of some, but not all microalgae. High Cd adsorption was found inAnabaena lutea, Nodularia harveyana, andNostoc commune (Cyanobacteria),Chlamydomonas sp. (Chlorophyceae),Bumilleriopsis filiformis (Tribophyceae), and inEctocarpus siliculosus, Halopteris scoparia andSpermatochnus paradoxus (Phaeophyceae). The specific surface (m2 cm–3) of the various microalgae was determined by means of laser diffractometry.Anabaena inaequalis andA. lutea (Cyanobacteria) and the Phaeophyceae had especially high Cd adsorption per surface unit. Most of the Cd adsorbed to these various materials could be desorbed subsequently with diluted mineral acid (pH 2).  相似文献   

19.
The results of allozymic, morphologic and morphometric studies performed on three parapatric shrews of the genusSorex from northern Italy are presented. These data clearly indicate: (1)Sorex samniticus is genetically well differentiated from S. araneus andS. arunchi, displaying a high mean value of genetic distance in comparison with the other two species (D=0.463). (2)S. araneus andS. arunchi display low values of genetic distance (D=0.007) and the latter shows lower levels of genetic variability. Altough no fixed allele difference was observed, an exclusive allele (Lap-2 96) is present inS. arunchi at low frequence, another one (Pgm-1 96) is rare inS. araneus and quite frequent inS. arunchi, and several alleles (12) ofS. araneus are missing in S. arunchi. In S. araneus some of these alleles are quite frequent. (3) Strong morphometric differences betweenS. araneus andS. arunchi permit to distinguish these parapatric shrews with great accuracy, also in some cases of marginal sympatry. These evidences support the hypothesis thatS. arunchi might be a recent (end of Pleistocene-lower Holocene) relict of the subgenusSorex s. s.  相似文献   

20.
Mary E. Endress 《Brittonia》2004,56(4):307-313
Three new species ofMalouetia (Apocynaceae) are described and illustrated:M. amazonica andM. pumila from Brazil andM. gentryi from Peru.Malouetia amazonica grows in inundated igapó forest, whereas the other two are found in non-inundated habitats:M. pumila incampa fechada, andM. gentryi in upland forest.  相似文献   

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