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1.
Summary Satellite DNAs of theDrosophila willistoni group have been analyzed by Hae III endonuclease digestion. Differences were observed between the 2 speciesD. willistoni andD. paulistorum and also between semispecies ofD. paulistorum and, to a lesser extent, between subspecies ofD. willistoni. Differences did not appear to be consistently greater between strains producing sterile hybrid males than between those producing fertile hybrids.This work was supported by grants 78.01852.65 from the CNR (Rome) and GM 22221 from the PHS (USA).  相似文献   

2.
Summary The chromosomes ofBufo rubropunctatus andB. chilensis (on basis of adults) are described for the first time. These chromosomic sets are compared with the karyotypes ofB. spinolosus andB. variegatus and other species ofspinolosus group. The importance of the secondary constrictions applied to the phylogeny ofBufo are discussed.Supported by Proyecto N0 S-77-47, Dirección de Investigación, Universidad Austral de Chile.I would like to thank Dr J. M. Cei for collecting the Argentinian toads. Mr N. Diaz collected the specimens from Santiago, Chile.The technical assistence of Sonia Lacrampe is acknowledged with appreciation.  相似文献   

3.
Summary 3 protogynous hermaphrodites were found in a domesticated strain ofXiphophorus helleri, confirming much doubted observations by older authors. It therefore seems that sex determination may vary between strains, certain strains being strictly gonochoristic but others being capable of true hermaphroditism.  相似文献   

4.
Summary Individuals showing anterior-posterior gynandromorphism or somatic mosaicism of palpi respectively have been found in a laboratory strain ofCulex pipiens fatigans. The origin of the gynanders on the basis of binucleated eggs bearing anm factor and independently fertilized by male gemetes ofM andm genotype respectively has been suggested.This study was supported by the grant (No. 7/112/919/81 EMR-1), Council of Scientific and Industrial Research Govt., of India.  相似文献   

5.
Summary 7 monoterpenes, -pinene, -pinene, myrcene, p-cymene, limonene, neral and geranial, were identified together with n-undecane in the scent scales ofP. melete, and also, together with considerable amounts of linalool, in the scent scales ofP. napi. Content ratio of neral to geranial inP. melete ranged from 0.77 to 1.04, and that inP. napi from 1.84 to 2.43. The present chemotaxonomic approach shows the 2 species ofPieris to be distinct.The authors thank Dr T. Yushima (National Institute of Agricultural Science, Japan) for supplying the references 3 and 4.  相似文献   

6.
Résumé Le karyotype normal deMyzus persicae (Sulzer) provenant de diverses sources fut de 2n=12. Une forme anholocyclique verte de cette espèce possède un karyotype de 2n=13 ou 2n=14, avec 1 ou 2 autosomes non appariés. Une comparaison des dimensions relatives des chromosomes des karyotypes normaux et anormaux suggère que ces derniers dérivent des chromosomes par fragmentation.

The work is sponsored by a British Science Research Council grant for research on variation inM. persicae, as part of the United Kingdom contribution to the International Biological Programme project on biological control of aphids.  相似文献   

7.
Summary Infective stage juveniles ofNeoaplectana carpocapsae (Steinernematidae) andHeterohabditis heliothidis (Heterorhabditidae) were able to penetrate through the alimentary tract of young tadpoles ofHyla regilla (Hylidae) andXenopus laevis (Pipidae) and enter the body cavity. Some infectives ofN. carpocapsae were able to release their symbiotic bacterium,Xenorhabdus nematophilus inside the host and in two cases, the nematodes developed into adult females before they perished. Tadpole mortality was associated with foreign bacteria entering the penetration holes made by the invading nematodes. The infective stage juveniles of both nematodes frequently encountered a host defense reaction upon reaching the tadpole's infective stage juveniles of both nematodes frequently encountered a host defense reaction upon reaching the tadpole's coelom.  相似文献   

8.
Summary The mating call of Pelodytes punctatus was analyzed by oscillograms and sonagrams. Above water surface, 2 types of call differing in several parameters are uttered in alternation. There is also a release call. The mating call, not uttered in series and consisting simply of uniform, short, noise-like sound pulses, seems rather undifferentiated compared with the Pelobatinae, a view supported by the more primitive habits ofPelodytes.  相似文献   

9.
Summary In two strains ofC. convexus, an Isopod which is known to be sex-determined by a polygenic system, monofactorial sex determination has been found. This is considered to be the result of an evolutionary step from polygenic to gonosomal sex determination within the species.  相似文献   

10.
Summary From sting extracts ofApis dorsata andA. florea, a substance was isolated which is active in alarm behaviour of both of these species but not ofA. mellifera andA. cerana. The active substance was identified as 2-decen-1-yl-acetate.  相似文献   

11.
Summary In the testes ofMyrmica sulcinodis there are not only haploid and some diploid cells to be found, as in the testes ofM. ruginodis, M. sabulsti andM. rubida, but a large mass of cells that have only half the haploid chromosome number. The diploid chromosome number ofM. sulcinodis is 56, those of six otherMyrmica species are between 42 and 48.  相似文献   

12.
Summary Growth of 14 strains from fiveChlorella species is rather insensitive towards cadmium. One strain (211-1a) ofC. saccharophila, however, was found to have a sensitivity towards this toxic heavy metal about 100 times higher than that of the other strains ofC. saccharophila.Acknowledgment. For excellent technical assistance I am indebted to Mrs U. Knoch and Mrs E. Weitemeyer.  相似文献   

13.
Summary The chromosome complement ofSorex minutus L. has been determined. The caryotype is characterized by a diploid number of 42 and by aNF (fundamental number) of 56. The sex-chromosomes are of theX−Y type usual in mammals. The origin and the evolution of the chromosome set ofS. minutus, S. unguiculatus, andS. araneus have been discussed.   相似文献   

14.
Summary Comparative DNA values obtained by Feulgen cytophotometry for 3 species ofProtopterus, as well as karyotype analysis, show the existence of a diploid-tetraploid relationship within the genusProtopterus.Research supported by the Division of Human Genetics, K. U. Leuven, Belgium, and by the Université Nationale du Zaire, campus Kinshasa, Zaire. The Department of Human Genetics, University of Amsterdam. The Netherlands, provided laboratory facilities for cytophotometric analysis. I thank J. Bylsma, A. Debont, F. Koperdraad and H. Van den Berghe for advice, R. Ruysschaert and G. Warmoes for hospitality and technical assistance and T. Mohsen for the generous gift ofP. annectens from Senegal.  相似文献   

15.
Summary The chromosomes of three species ofPachybrachis and nine ofCryptocephalus chrysomelids were analyzed. The male meiotic bivalent formula ofP. azureus Suffr.,P. catalonicus Burl. andP. petitpierrei Daccordi is 7II+Xyr.Cryptocephalus sexmaculatus Ol. andC. vittula Suffr. have 13II+Xyp,C. bipunctatus L. 14II+Xyr,C. ochroleucus Steph. andC. ocellatus Drap. 14II+Xyp,C. crassus 01. 15II+Xyr,C. sulphureus 01. 15II+Xyp, the same number as inC. fulvus Goeze with 2n=32 chromosomes, whileC. primarius Har. has 19II+Xyp. The modal chromosome number inCryptocephalus is 2n=30 (about 60% of spp.), and most species are characterized their small chromosomes. The low variation found in the karyotypes of Cryptocephalinae along with their possible interrelationships with allied chrysomelid subfamilies are also discussed.  相似文献   

16.
Summary The karyotype of the African PipidHymenochirus boettgeri (2n=24, all meta- or submetacentric chromosomes) is different from the one of the African PipidXenopus laevis (2n=36). The karyotype of the American PipidPipa (Protopipa)parva (2n=30, all acrocentric chromosomes) is very primitive and different from the karyotypes of the African Pipids and from that ofPipa pipa; the male meiotic chromosomes ofP. parva, usually with 1 procentric chiasma, show a clear difference from the male bivalents of the other Pipids, all with 2 terminal chiasmata.  相似文献   

17.
Summary Problems connected with the food uptake of the aphidMegoura viciae Buckt., sucking in the phloem ofVicia faba, are studied by means of radioactive phosphate.Outside the phloem there is no intake of food by the stylets of the aphid. They are able to reach the phloem earliest 7 min after the beginning of the puncture. But only 3 h later all aphids have reached the phloem. The variability in time taken to reach the phloem is very high. The aphids seem not to be able to aim at the phloem, presumable this process is more or less incidentally. In plants, which do not belong to the host plants ofMegoura viciae, the aphid also pierces the phloem. Perhaps the aphids first in the phloem find out their host plant. The course of the ingestion of food is studied in relation to the time of sucking and shown in a diagram.  相似文献   

18.
The karyotype of a lungless salamander,Onychodactylus fischeri, from Korea was analyzed and compared with that of the Japanese congeneric species,O. japonicus. In both species the diploid karyotype consists of78 chromosomes, including 6 pairs of large chromosomes, 6 pairs of medium-sized ones, and the remaining 27 pairs of microchromosomes. The chromosome number ofO. fischeri, 2n=78, is, like that ofO. japonicus, the largest so far reported in the order Urodela. C-banding showed that constitutive heterochromatin inO. fischeri was mainly in the centromeric regions and near the secondary constrictions of the large chromosomes. AgNO3-bands were located in the secondary constrictions associated with C-band heterochromatin.  相似文献   

19.
Summary Exposure ofEarias vittella adults to vapors ofBlumea eriantha oil reduced their mating ability, predominantly the males were affected.  相似文献   

20.
Summary Ammonium ions alone will activate both vesicula and inseminated spermatozoa ofBalanus balanoides. Maximum activity, however, occurs when inseminated spermatozoa are treated with the blood and oviducal gland fluid ofB. balanoides.Acknowledgments. I should like to thank Mr K. White for the ammonia determinations and Prof. D. J. Crisp and Dr P. A. Gabbott for useful discussions.  相似文献   

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