Initial transdetermination in the first leg discs of differentDrosophila species

Initial transdetermination leads from lateral and medial halves of male first leg imaginal discs almost exclusively to structures of the base and the spread (blade) of the wing. Mesonotum never appeared. The frequency of transdetermination is species-specific and most probably cell-autonomous. Medial halves transdetermine more frequently than lateral halves. Under the influence of an equivalent amount of blastema growthD. nigromelanica transdetermine with a much higher frequency thanD. virilis.     

2-Phenylethanol,a presumed sexual stimulant produced by the male cabbage looper moth,Trichoplusia ni

Summary A sex pheromone produced by male cabbage looper moths,Trichoplusia ni (Hübner), has been isolated from the genital scent brushes and identified as 2-phenylethanol. It is shown conclusively to elicit specific behavioural responses in the female (such as wing vibration and abdominal elevation), as determined by a novel behavioural laboratory bioassay. This is taken as further evidence that the male pheromone ofT. ni acts as a sexual stimulant (aphrodisiac) prior to mating. 2-Phenylethanol represents the first identification of a genital scent brush pheromone in the family Noctuidae, and of a male pheromone in the subfamily Plusiinae.Mention of a proprietary product in this paper does not constitute a recommendation or an endorsement of the product by the U. S. Department of Agriculture.     

The lateral neurosecretory cells and mating instinct in maleDysdercus koenigii (Hemiptera: Pyrrhocoridae)

Summary 5 pairs of median and 1 pair of lateral neurosecretory cell groups occur in the protocerebrum of maleDysdercus koenigii, a hemipteran pest on Hibiscus esculentus. The lateral neurosecretory cells (LNSC) are in a state of peak activity when the male engages itself in copulation. 24 h later, the LNSC are found to be inactive, but they again resume their activity 96 h after commencement of copulation. Such males soon start mating if they find another receptive female. It is believed that the secretion of LNSC in maleDysdercus koenigii is responsible for the onset of the urge for mating just as in female insects.     

Regulation of male sex determination: genital ridge formation and Sry activation in mice

Sex determination is essential for the sexual reproduction to generate the next generation by the formation of functional male or female gametes. In mammals, primary sex determination is commenced by the presence or absence of the Y chromosome, which controls the fate of the gonadal primordium. The somatic precursor of gonads, the genital ridge is formed at the mid-gestation stage and gives rise to one of two organs, a testis or an ovary. The fate of the genital ridge, which is governed by the differentiation of somatic cells into Sertoli cells in the testes or granulosa cells in the ovaries, further determines the sex of an individual and their germ cells. Mutation studies in human patients with disorders of sex development and mouse models have revealed factors that are involved in mammalian sex determination. In most of mammals, a single genetic trigger, the Y-linked gene Sry (sex determination region on Y chromosome), regulates testicular differentiation. Despite identification of Sry in 1990, precise mechanisms underlying the sex determination of bipotential genital ridges are still largely unknown. Here, we review the recent progress that has provided new insights into the mechanisms underlying genital ridge formation as well as the regulation of Sry expression and its functions in male sex determination of mice.     

Bacterial signal peptide recognizes HeLa cell mitochondrial import receptors and functions as a mitochondrial leader sequence

Phage display was used to identify new components of the mammalian mitochondrial receptor complex using Tom20 as a binding partner. Two peptides were identified. One had partial identity (SMLTVMA) with a bacterial signal peptide from Toho-1, a periplasmic protein. The other had partial identity with a mitochondrial inner membrane glutamate carrier. The bacterial signal peptide could carry a protein into mitochondria both in vivo and in vitro. The first six residues of the sequence, SMLTVM, were necessary for import but the two adjacent arginine residues in the 30-amino-acid leader were not critical for import. The signal peptides of Escherichia coli β-lactamase and Bacillsus subtilis lipase could not carry proteins into mitochondria. Presumably, the Toho-1 leader can adopt a structure compatible for recognition by the import apparatus.Received 29 April 2005; received after revision 8 June 2005; accepted 17 June 2005     

Occurrence of a pheromone-producing gland in female tobacco beetles

Summary A pheromone-producing gland was discovered in the second abdominal segment of virgin female tobacco beetles,Lasioderma serricorne (Fabricius). The gland duct extends to an orifice below the genital pore and is supported by a rigid invagination of the integument. Hexane extracts of intact pheromone glands were found attractive to male tobacco beetles and also induced high receptor potentials in the olfactory sensilla of the antennae of maleL. serricorne. A surface extract of virgin females proved to be significantly more attractive than an extract of pheromone glands.     

Homoplastische Transplantationen embryonaler Zellen in differenzierte Gewebe

Summary The intermediate mesoderm (8th–12th somite) of early tailbuds ofTriturus alpestris was transplanted into the lateral body wall of 12 mm larvae. The differentiation of opisthonephros tubules, primordial gonad and a new coelom was observed in 21 mm larvae 23 days after implantation.     

Obtention,par la méthode des greffes de gonades embryonnaires,d'une femelle à descendance unisexuée femelle,chez le TritonPleurodeles waltlii Michah.

Summary Thanks to a method established byHumphrey ³ inAmbystoma sp. and founded on the orthotopic transplantation of the lateral mesoderm corresponding to the gonad primordium, we have produced, in the SalamanderPleurodeles waltlii Michah., 1 female which gives rise uniquely to female individuals. In this species, it is also possible to obtain, by an oestrogenic treatment during the larval stages of development, neo-females, these are genetic males feminized into phenotypic and perfectly functional females and their offsprings are uniquely composed of males². The ability to experiment at will with unisexual, male or female, offsprings allows us to attack from a new basis, before any perceptible gonadic sex differentiation, the analysis of the mechanisms of this differentiation in the SalamanderPleurodeles waltlii Michah.     

Action des températures élevées sur la reproduction du planorbeBiomphalaria glabrata (gastéropode pulmoné)

Summary A temperature of 33°C increases growth of young snails but not that of adults. Adult fecundity is reduced and young snails do not reach sexual maturity. Oogenesis remains normal but late stages of spermatogenesis are scarce. The weight of the albumen gland in adult snails is increased, as is that of the albumen gland and the female part in young specimens. High temperatures, however, do not prevent differentiation of the genital apparatus but disturb its functioning.     

Isoenzymes de la lactate deshydrogenase au niveau des organes de l'appareil génital du rat mâle greffé avec une tumeur de la glande interstitielle du testicule

Summary The LDH isoenzyme pattern was determined at the level of the genital apparatus organs in the male rat grafted with a testicular interstitial gland tumor. The seminal vesicles exhibit a modified pattern in the grafted animals after 2 months in comparison with the non-grafted rats. The pattern of the tumoral extract, in fact a true leydig cells extract, does not exhibit the specific testicular band-X.

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Isoenzymes de la lactate deshydrogenase au niveau des organes de l'appareil génital du rat mâle greffé avec une tumeur de la glande interstitielle du testicule

     

2-Phenylethanol, a presumed sexual stimulant produced by the male cabbage looper moth, Trichoplusia ni.

A sex pheromone produced by male cabbage looper moths, Trichoplusia ni (Hübner), has been isolated from the genital scent brushes and identified as 2-phenylethanol. It is shown conclusively to elicit specific behavioural responses in the female (such as wing vibration and abdominal elevation), as determined by a novel behavioural laboratory bioassay. This is taken as further evidence that the male pheromone of T. ni acts as a sexual stimulant (aphrodisiac) prior to mating. 2-Phenylethanol represents the first identification of a genital scent brush pheromone in the family Noctuidae, and of a male pheromone in the subfamily Plusiinae.     

Osservazioni preliminari,chimiche e farmacologiche,sulla murexina

Summary (1) Murexine, a new choline derivative found in the hypobranchial body ofMurex trunculus, Murex brandaris, andTritonalia erinacea, was isolated as picrate, picrolonate, styphnate, flavianate, and reineckate. Some preliminary characteristics of these salts are given.(2) The murexine content of the median zone of the hypobranchial body ofMurex trunculus is extremely high: murexine picrate equivalents of 45–70 mg per g fresh tissue are commonly observed.(3) Murexine manifests intense nicotinic and curariform actions, but is practically wanting in any muscarinic activity.The central nervous system is strongly affected by the substance: at first stimulation seems to prevail, but later on, with larger doses, a deep depression regularly develops.In decapitated cats and dogs murexine causes a significant rise in blood pressure, which is due, at least partially, to a liberation of epinephrine from the adrenal medulla and from the adrenergic nerve terminals.On the enucleated eye of frogs andOctopoda the substance acts to cause mydriasis and expansion of the iris chromatophora.

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V. Erspamer eF. Dordoni, Arch. int. Pharmacodyn.74, 263 (1947).     

Regenerattypen der Flügelimaginalscheibe beiAntheraea pernyi Guér. und anderen Großschmetterlingen

Summary By reason of their different development out of the hypodermis, the regenerates of the imaginal wing discs may be divided in 4 groups. Within group A they show the normal imaginal wing discs development, in group B this process is modified and in group C they show a more primitive type of imaginal wing disc development. An imaginipetal tendency of the initial development is manifested in group C and D.     

Tissue distribution of juvenile hormone hydrolytic activity inGalleria mellonella larvae

Summary Juvenile hormone (JH) hydrolytic activity was determined in different tissues of day-4 last instar larva ofGalleria mellonella. Midgut, gonad, imaginal wing discs and fat body contain higher JH hydrolytic activity than hemolymph, while silk gland and body wall have lower activity. JH esterase activity in imaginal wing discs exhibits a pattern of age-related changes different from that of the hemolymph.We acknowledge the support of this research by the National Institutes of Health (GM 22429) and the Johnson Wax Foundation. Address to which reprint requests may be sent.     

Durch polarisiertes Licht hervorgerufene Optomotorik beiUca tangeri

Summary Optomotor reactions were tested in 10Uca tangeri (5, 5) of intermediate body size, by slowly rotating the plane of polarized light entering the apical ommatidia of the animal; 8 out of 10 animals showed definite optomotor reactions immediately at, or a short time after, the beginning of the rotation. There were no such reactions when the apical ommatidia were stimulated by a rotating black and white disc.     

An immune response-dependent mechanism for the vertical transmission of an entomopathogen

Summary An exceptionally efficient mechanism for the vertical transmission of a parasitic gregarine is dependent on the insect host's immune response. Gametocysts ofAscogregarina chagasi on the genital accessory glands of adult female sand flies (Lutzomyia longipalpis) become encapsulated through hemocyte-mediated immune reactions. Oocysts ofA. chagasi, ejected into the lumen of the glands owing to pressure exerted by this capsule, become glued to eggshells and are subsequently ingested by larvae. InL. longipalpis with an experimentally suppressed encapsulation reaction, fewer accessory glands contained oocysts ofA. chagasi.     

Neurosécrétion et régulation hydroélectrolytique chezArtemia salina

Summary The activity ofArtemia protocerebral median neurosecretory cells is stimulated when animals are grown in media whose tonicity is lower than that of sea weater. The substance liberated by these cells could regulate the tonicity of the internal medium.

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Neurosécrétion et régulation hydroélectrolytique chezArtemia salina

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Travail réalisé avec l'appui financier du FRFC (programme No 2.9010.75).     

Alteration of thoracic macrochaet development inDrosophila

Summary Incisions into 5 areas of the right dorsal mesothoracic disc in matureDrosophila larvae produced 2 types of alteration of macrochaet development. Macrochaets tended to be lost most commonly in the notopleural areas, and duplicated in the scutellum.     

Zur Spaltung von Adenosintriphosphat durch die Z-Scheiben der indirekten Flugmuskeln vonPhortnia regina (Diptera)

Summary ATP splitting is demonstrated to occur in the Z discs of isolated flight muscle myofibrils ofPhormia regina after the quantitative extraction of myosin.