摘要:

The effects of cutting gonapophyses were evaluated on the ovarian response two or four days after amputation in imaginai molt decapitated femalesBlaberus craniifer.Sites binding anti‐egg protein antibodies were detected in the periphery of basal oocytes in 68% operated females. In headlessBlaberus craniifer,the onset of vitellogenesis which is triggered by extraphysiological doses of juvenile hormone or indolamines, was induced by this surgical procedure. It is suggested that amputation of gonapophyses affects the delivery of natural messengers inducing vitellogenesis at physiological concentration.

ISSN:0373-4137    

DOI:10.1080/11250009309355784

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The sperm structure of some genera belonging to Cecidomyiidae dipterans is reported. Spermatozoa are immotile, as their axonemal doublets are devoid of dynein arms. Sperm cells ofContariniaand related genera (Allocontarinia, Lestodiplosis, Myricomya)arecharacterized by a flattened tail with the plasma membrane adapted to form orderly evaginations, each containing a microtubular doublet. The results do not support the inclusion of the genera among members of the subfamily Cecidomyiinae.Syndiplosis,retained to be a synonym ofContarinia,has a different sperm structure. The results are discussed in relation to the traditional taxonomy. A hypothetical evolution of the group based on the different sperm models till now described is also proposed.

ISSN:0373-4137    

DOI:10.1080/11250009309355785

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The distribution pattern of some hydrolytic and oxidizing enzymes amongBotryllus schlosserihemocytes has been investigated histochemically. Signet‐ring cells, macrophages, and some hyaline amoebocytes were found to stain positively for phosphatases, glycosidases, and esterases, and morula cells and some granular amoebocytes for arylsulfatase, peroxidase, and phenoloxidase. Our results suggest two differentiation pathways for these blood cell types: one involves hyaline amoebocytes, signet‐ring cells, and macrophages and leads to phagocytic cells; the other involves granular amoebocytes and morula cells and leads to cells responsible for inflammatory responses.

ISSN:0373-4137    

DOI:10.1080/11250009309355786

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The cell content of the hemolymph from the two species of stick insectsBacillus rossiusandCarausius morosuswas characterized in morphology and cytoskeletal distribution by flow cytometric analysis, phase‐contrast microscopy, and scanning electron microscopy. Inin vitrocultured hemocytes, the cytoplasmic distribution of F‐actin microfilaments was revealed with Rhodamine‐labelled phalloidin, and that of microtubules by indirect im‐munofluorescence with a monoclonal anti α‐tubulin. The results show that both stick insects possess peculiar hemocyte sub‐populations, as detected by flow cytometry, composed of plasmatocytic and granulocytic cells.Carausius morosushas a hemocyte subtype, the spherulocyte, that appears to be lacking inBacillus rossius.The results of cytoskeletal analysis show that the plasmatocytes of both species, smeared on glass coverslips and compared with cultured mammalian epithelial control cells, possess a regular cytoskeletal network, with F‐actin microfilaments organized in stress‐fibres, and microtubules spanning the cytoplasm. In rounded, non‐plasmatocytic cells, the F‐actin stress‐fibres were not detected, and the microtubules were arranged in a fashion resembling that present in human lymphocytes. These data may reflect different functional and/or immunological specializations among stick insect hemocyte subpopulations, and suggest similarities in cytoskeletal organization and cell isotypes between insect and vertebrate blood cells.

ISSN:0373-4137    

DOI:10.1080/11250009309355787

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Head and mouth structures of the mesophyllomyzous speciesZyginidia pullula(Typhlocybinae), the phloemomyzousEmpoasca vitis(Typhlocybinae), and the xylemomyzousGraphocephala fennahi(Cicadellinae) were examined and shown to be very similar. On the other hand, the ratios between the lengths of mandibular and maxillary stylets were closely comparable in the two typhlocybines, but lower than that of the cicadelline, and apparently correlated with the systematic group rather than with the trophic behaviour

ISSN:0373-4137    

DOI:10.1080/11250009309355788

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

We propose a standardized karyotype for the raccoon(Procyon lotor;2n = 38, FN 74) and compare it with that of the domestic cat (2n = 38, FN 72). Numerous chromosomes (12) have similar and sometimes identical G‐banding and 14 chromosome pairs have remained intact. Other chromosomes apparently differ by Robertsonian translocations and inversions. The conservation of these karyotypes is remarkable considering that the divergence of procyonids and felids predates 50 million years B.P. However, the common diploid number of 38 is not a primitive retention, as sometimes hypothesized. Instead, cats and raccoons converged on this chromosome number by a different series of translocations. The unsolved problems of carnivore phylogeny could benefit from a combination of high resolution banding and molecular cytogenetic analyses.

ISSN:0373-4137    

DOI:10.1080/11250009309355789

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The results of karyological and electrophoretic analyses of the garden dormouse,Eliomys quercinus dalmaticus,collected at two localities in Yugoslavia are reported. The karyotype consists of 48 chromosomes (FNa = 86). The chromosome morphology, as revealed by differential staining, is the same as inEliomys quercinus pallidusfrom central Italy, but differs in two pairs of chromosomes fromE. quercinus lusitanicusfrom Spain. Comparison betweenE. g. dalmaticusand other chromosomal races of the garden dormouse, by electrophoretic analysis of 41 gene loci, suggests a different origin for central European and Alpine populations

ISSN:0373-4137    

DOI:10.1080/11250009309355790

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The karyotype and the NOR localization of five taxa of Heteronemiidae, belonging to the three genera known from Somalia are reported. The cytotaxonomy of stick insects in general and, in particular, of Heteronemiidae is rather poorly developed. The present paper aims to contribute to filling this gap. Diploid chromosome numbers are:Ramulus sansibarus,44;R. lingulatus, R. affinisandBurria longixipha,42;Palophus rothschildi,32; the X chromosomes are the largest of the complement, and all taxa have an XX‐XO sex determination mechanism. In spite of the numerical similarity of the ramuline set, karyotypes differ markedly for chromosome constitution, their haploid N.F. ranging from 20 to 30, and for satellite/Ag‐NOR localizations. IfR. libanicus(2n = 30, XX‐XY) is also considered, it can be seen that karyotype differences of taxa presently ascribed to the genusRamulusare of the same magnitude as those of heterogenerically related species. The karyological features, together with morphological and ootaxonomical data, clearly suggest a genus splitting into at least three species‐groups: thesansibarus‐,theaffinis‐and thelibanicus‐like artenkreis.

ISSN:0373-4137    

DOI:10.1080/11250009309355791

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The life cycle ofEphydatia fluviatilisinvolves obligatory gemmule formation, a process strongly related to environmental conditions. A comparative investigation carried out on three populations of this species distributed along a climatic gradient, besides confirming a link between occurrence of gemmules and the severity of the habitat, evidences that gemmulation may be triggered even by endogenous stimuli. Indeed, in the northern area (Torrente Scrivia, Liguria), subjected to ice‐up and notable thermic and water‐flow fluctuations, the sponges hibernate for a long period and show shorter summer activity. In the southern area (Canale Tagliavla, Sicily), with a summer dry‐up, the active sponges are present during the winter, while the quiescence coincides with an aestivation. The persistence of this rhythm over the years is discussed, also in consideration of a speciation trend which points to a physiological reproductive barrier between these metapopulations. By contrast, in the intermediate area (Rio Bunnari, Sardinia), notwithstanding the lack of a summer dry‐up, the population shows a short summer quiescence. This life cycle, not depending on environmental factors, supports the hypothesis of an intrinsic rhythm inducing the quiescence ofE. fluviatilis.

ISSN:0373-4137    

DOI:10.1080/11250009309355792

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Immediate and delayed effects of mercury on the marine sand dwelling annelidNerilla antennatawere studied. Short static tests were performed on embryos, juveniles, and adults using different mercury concentrations, and the dose lethal to half of tested specimens was determined for each stage. Detectable effects of the teratogenic action of mercury were morphological anomalies, which most frequently affected appendages of the cephalic region.

ISSN:0373-4137    

DOI:10.1080/11250009309355793

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor