蛆症异蚤蝇减数分裂染色体观察

以蛹精巢和卵巢组织为材料,采用空气干燥法制备染色体标本,Giemsa和硝酸银分别染色,对蛆症异蚤蝇Megaselia scalaris减数分裂染色体行为进行研究。结果表明:蛆症异蚤蝇的染色体数目n=3,由2条中着丝粒染色体和1条端着丝粒染色体组成;粗线期,第2条二价体具有较强的嗜银性,可能为性染色体;晚粗线期,第1条二价体的同源染色体之间出现一条细线,类似于联会复合体;终变期,第2条二价体形成环状结构;晚终变期,在3条二价体染色体臂上均产生条带,根据二价体着丝粒处是否成环可以将3条二价体分开。     

Unequal X Chromosomes in Bradysia Hygida (Diptera:Sciaridae) Females: Karyotype Assembly and Morphometric Analysis

The mitotic chromosomes of Bradysia hygida(Diptera:Sciaridae) neuroblast cells are described together with their morphometric data. Giemsa-stained neuroblast chromosomes from female and male larvae confirm the chromosome number of this species, 2n=8 (XX) and 2n=7 (XO), respectively. The karyotype assembly reveals two metacentric autosomic pairs, the A and B chromosome; a subtelocentric, the C chromosome, the smallest one; and a sexual unequal metacentric pair, X chromosome, in female karyotype and a one sexual metacentric X chromosome in male. The implications of the unequal X chromosome pair are discussed.     

Cytotaxonomy ofCalliphoridae (Diptera)

A modification of the general system of classification ofCalliphoridae is proposed in this report. Information about the chromosome complements of about 90 species is provided including references to the earlier literature on chromosomes of this family. With one exception all species studied by us or by earlier investigators have 2n=12. The total complement length of 556 complements from 83 species averaged 66.4 μ. Most species have a short heteromorphic sex pair but the size and morphology vary considerably and one species,Hemipyrellia fernandica, seems to have a quadrivalent sex-chromosome complex in a 2n=14 complement. The autosomal pairs vary in both length and arm ratios between the species but seem to be more stable than the sex chromosomes. Only minor variations were found between different collections of the same species except for two collections ofCalliphora croceipalpis. Although presently available data on the chromosomes of Diptera species suggest that increases in total complement length accompany evolutionary progress, no such general trends were obvious in either the total complement lengths or chromosome morphology, either within or between the tribes ofCalliphoridae. Thus the karyotypical reorganizations in the family have apparently not been directly associated with changes in the general morphological features of the adults which may have responded in these respects more extensively to genetic mutations.     

Chromosomes de Muridae (Microtinae et Cricetinae)

Sans résumé     

Chromosomes of villadia and altamiranoa (crassulaceae)

Villadia, ranging from Texas to Peru with some 25 species, has a rather distinctive thyrsoid to spicate inflorescence, and we keep it as a genus separate from Sedum. Twenty species show every gametic chromosome number from 9 to 17 and also 20-22 and higher. Chromosome pairing in hybrids shows that the species differ by many translocations and that species with 21 or lower are effectively diploid. More specialized species tend to have fewer and larger chromosomes, suggesting that through time translocations have rearranged the ancestral genome into fewer units. We suspect that relocated genes may be programmed differently, affecting phenotype. Thus Villadia is like Echeveria in having a remarkably long descending series of evidently diploid chromosome numbers. Altamiranoa, often included in Villadia, with about 15 species from Mexico south, more closely resembles Sedum in its broadly cymose inflorescence. It appears polyphyletic, with no clear boundary from Sedum, and we disperse its species in Sedum. The ten species studied have gametic numbers from 20 to 29 that probably are effectively diploid, with a few higher and probably polyploid. Again, chromosome pairing in hybrids shows that the species differ by many translocations. Putative relatives in Sedum section Leptosedum have n = 26 to 31. Thus cytologically as well as morphologically Altamiranoa has remained more similar than Villadia to its Sedum relatives.     

Chromosomes and polyploidy in Lenophyllum (Crassulaceae)

Gametic chromosome numbers of 22, 32, 33, and 44 in five species of Lenophyllum suggest that they may be polyploids on a basic 11, but this number has not been found. Three species have 8-12 distinctively large chromosomes that do not pair with each other in their hybrids and probably belong to the same genome. In hybrids of many polyploid Mexican Crassulaceae preferential pairing occurs between corresponding chromosomes of their multiple genomes, which indicates that they are autopolyploids. However, little or no preferential pairing occurs between chromosomes of Lenophyllum in its hybrids, and its species appear to be allopolyploids. The putative parents are unknown.     

Phylogeny of Culicomorpha (Diptera)

The phylogeny of the families of Culicomorpha and their closest relatives are cladistically reinvestigated adding published information from several sources. A revised data matrix is presented and some characters are discussed. Different outgroups and options used, characters unordered or ordered, the results reweighted or not and the results discussed. Nymphomyiidae in all cladograms, alone or together with Thaumaleidae, forms the sister group of the traditional Culicomorpha and should be included in this infraorder as suggested by others. Superfamily Chironomoidea is not monophyletic as Thaumaleidae or Nymphomyiidae + Thaumaleidae form the sister group to the remaining traditional Culicomorpha. The mutual relationships of Chironomidae, Simuliidae and Ceratopogonidae are variable between cladograms. They form a monophyletic group with Chironomidae and Simuliidae as sister groups when characters are unordered and reweighted or when some characters are ordered, others unordered and the result reweighted. When the characters are ordered, or when a combination of ordered and unordered are used they form a Hennigian comb with the phyletic sequence Chironomidae/Ceratopogonidae/Simuliidae. When characters are ordered and reweighted the phyletic sequence is Chironomidae/Simuliidae/Ceratopogonidae. Culicoidea is monophyletic in all cladograms, but the division into superfamilies is not warranted.     

Phagostimulants of haematophagous tabanids (Diptera)

Factors that monitor the dispatch of ingested food to crop and/or midgut were examined. Amino acids in aqueous solution (at 0.05 M and 0.005 M) with fixed pH were largely ineffective, however, some activity was noticed when a select group of these were offered in a phosphate buffer (0.133 M:pH 7.4). Of the three nucleotides tested (ATP, ADP and AMP), only ATP in phosphate buffer showed stimulatory effect.The crop was the locus of ingested sugars and blood was dispatched to the midgut immediately after ingestion. The same was true of wild-caught females. Molar concentration of glucose and its volume in the blood-glucose mixture was critical and determined whether or not the ingested meal went to crop and/or midgut.It is suggested that the sensilla in the cibarium may be involved in this dispatch mechanism. Positive stimulation of receptor(s) sensitive to blood (henceforth called blood receptors) or the ones responsive to sugars (proposed as sugar receptors) may determine the direction of the food soon after ingestion to crop and/or midgut.

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Phagostimulantien blutsaugender tabaniden (diptera)

Zusammenfassung Bei Weibchen der Bremse Chrysops vittatus wurden die Rolle verschiedener blutbürtiger Chemikalien und des Nektarzuckers als Fraßstimulantia sowie die Faktoren untersucht, welche ihre Verteilung auf Kropf und/oder Mitteldarm bestimmen.Während die Aminosäuren in wäßriger Lösung keinerlei signifikante Aktivität hervorriefen, wurden einige Reaktionen beobachtet, wenn eine ausgewählte Gruppe derselben in Phosphatpuffer (ph 7,4) auf den Labellen geprüft wurde. Das Ausstrecken des Rüssels und die Spreizung der Labellenloben war dabei das Zeichen für eine positive Stimulation. Gepufferte ATP induzierte einige Aktivität, obwohl ATP, ADP und AMP in destilliertem Wasser und in 0,15 M NaCl weitgehend wirkungslos blieben.Die Fliegen nehmen Rohblut (teilweise), Glukose, Rohrzucker und Blut-Glukose-Gemische (in verschiedenen Anteilen und Konzentrationen) auf. Unmittelbar nach der Aufnahme wurden die Zucker dem Kropf und das Blut dem Mitteldarm zugeteilt. Die Bedeutung der molaren Konzentration zeigte sich bei Untersuchungen über den Verteilungsmechanismus. Höhere Konzentration (0,5 M) und größere Mengen von Glukose im Blut-Zucker-Gemisch bewirkte seine Zuleitung in den Kropf. Bei geringerer molarer Konzentration und geringerem Glukoseanteil ging das Gemisch in den Mitteldarm. Es wird vermutet, daß die Sensillen im Cibarium diesen Teil der Nahrungsaufnahme überwachen können. Reizung der auf Blut oder Zucker reagierenden Sensillen (hinfort als Blut- bzw. Zuckerrezeptoren bezeichnet) könnte den oder die entsprechenden sensorischen Mechanismen erregen, welche vielleicht entscheiden, ob die aufgenommene Nahrung in den Kropf oder in den Mitteldarm geleitet wird.

     

Phylogenetisch-systematische Studien an Bombyliiden (Diptera)

For the first time 16 subfamilies (26 genera) of the Bombyliidae are analyzed for their phylogenetic relationship, using the egg-laying system as principal criterion. It is concluded that the generally held division of the family into two subgroups should be abandoned, because a monophyletic group is only represented by the B. tomophthalmae. The assemblage of all Bombyliidae possessing a soil chamber to coat the eggs is proposed as B. psammophoridae.     

Tabanidae (Diptera) of Saudi Arabia

Samples were collected from southern, central and eastern regions of Saudi Arabia using Malaise traps and sweep nets. Nine species of Tabanidae were identified, two for the first time from Saudi Arabia, Hybomitra peculiaris (Szilády) and Atylotus pulchellus (Loew).Therefore, the total number of Tabanidae in Saudi Arabia is 31 species. Remarks of the species recorded in this study were given. A key to the genera of Tabanidae occurring in the Arabian Peninsula is also provided. Available literature for Saudi Arabian Tabanidae is summarized and provided. It is concluded that the tabanid fauna of Saudi Arabia is more similar to that of the Palaearctic region than to the Afrotropical region.     

Simuliidae (Diptera) of Sabah (British North Borneo)

This paper is based on collections made in Sabah by John Smart and on an examination of named material (types) in the British Museum (Natural History), London.
Segregates discussed comprise:(1) six new species, (2) five named species from the area, described by the late F. W. Edwards (1933).     

Chromosomes of Australian lygosomine skinks (Lacertilia: Scincidae)

The karyotypes of 25 species from the scincid genera Egernia, Corucia and Tiliqua have been investigated using C-banding, silver staining of nucleolar organiser regions (NORs) and Hoechst 33258 induced condensation inhibition. At least one member from each of the species groups of Egernia recognised by Storr et al. (1981) was studied. The three genera have very similar conventionally stained karyotypes of 32 chromosomes. Some species show departures from this basic karyotype but these are due to additions of C-band positive material. Silver stained. NOR patterns are variable but most species have a silver staining site on a pair of larger microchromosomes. All specimens studied except one have a proximal C-band on the acrocentric ninth pair, which shows failure to condense following treatment with the fluorochrome Hoechst 33258. Heterogamety was not observed in any species. Mabuya multifasciata, proposed as a relative of the Egernia group, while having 32 chromosomes does not share the C-band marker on pair nine, unique to the Egernia group. Tribolonotus gracilis, sometimes allied with the Egernia group, has 32 chromosomes and a similiar karyotype, but prominent procentric C-bands on all chromosome pairs obscure the detection of the proximal C-band marker on pair nine.     

Five Simuliidae (Diptera) from West Cameroon

The male, female, pupa and larva of a new phoretic species of Simulium are described. A new species-group is established for this species and S.diceros, and its systematic position is discussed. Two other new species of Simulium are described from pupal material, and new forms of S.palmeri and S.berghei are recorded.     

Phylogeny of Ptychopteroidea (Insecta: Diptera)

A phylogenetic tree is proposed for the superfamily Ptychopteroidea, reconstructed taking into account both extinct and extant taxa and based mainly on characters of wing venation.     

Untersuchungen zur bakteriensymbiose der trypetiden (Diptera)

Ohne ZusammenfassungHerrn Professor Dr. Paul Buchner in Verehrung gewidmet.Für die Anregung zu diesem Thema und für wertvolle Hinweise möchte ich Herrn Prof. Dr. H. J. Stammer meinen herzlichsten Dank aussprechen. Die bakteriologischen Untersuchungen wurden am Hygienischen Institut des Städtischen Krankenhauses Nürnberg durchgeführt. Mein besonderer Dank gilt Herrn Oberarzt Dr. Kellner, der mir in allen auftretenden bakteriologischen und technischen Fragen jederzeit zur Seite stand.