The mating behavior of individuals ofDrosophila pseudoobscura from New Zealand

Summary Recently discovered individuals in New Zealand of the North American speciesDrosophila pseudoobscura were analyzed for any divergence in mating behavior. Cultures collected from five localities in North American were mated with a stock from Rotorua, New Zealand. No significant divergence was obtained in any of the within North Americ, and more importantly, between North American and New Zealand mating experiments. Further analyses also showed no development of sterility between recently caught New Zealand and North American flies. We discuss our results in relation to others of this type.Publication No. 5 from the Evolutionary Genetics Laboratory, University of Auckland.Acknowledgements. We thank the University Grants Committee, grant No. 140Z88, for financial assistance. We thank D.G. Futch., L. Barr, A. Beckenach and H. Spencer for their kind assistance in sending us wild caught cultures.     

Frequency-dependent mating success among mutant ebony ofDrosophila melanogaster

Summary Measurements of the mating success of wild and ebony strains ofD. melanogaster with different degrees of competition have shown a frequency-dependent effect in both cases, but with a negative correlation for the wild and a positive correlation for the ebony strain.Supported by FAPESP Grant No. 70/049.     

Studies of selective mating using the melanistic mutants ofDrosophila melanogaster

Résumé L'observation directe a montré qu'il n'y a pas d'isolement sexuel entre le typesauvage et les mutants mélaniquesebony etblack deDrosophila melanogaster, mais il existe de notables différences entre l'activité sexuelle et motrice des mâles des trois génotypes. L'importance sélective de ces différences est soulignée.     

Light dependent mating inhibition in the white-eye mutant ofDrosophila pseudoobscura

Summary White-eyeDrosophila pseudoobscura males display a deficiency in their mating ability in the light, although they are able to mate readily in the dark. The present data suggest that the mating deficit is due to a neurobehavioral disruption produced by faulty visual input.     

Studies of selective mating using the sex-linked mutantsWhite andBar ofDrosophila melanogaster

Résumé L'observation directe montre qu'il n'y a pas d'isolement sexuel entre le typesauvage (Canton special) et les mutantsBar etwhite deDrosophila melanogaster. L'activité sexuelle des mâles est nettement moindre chezwhite etBar. Par contre les activités locomotrices ne semblent pas inférieures.     

Role of visual and auditory cues in mating behavior of two desert species ofDrosophila

Summary The effects of visual and auditory cues on mating behavior was examined for 2 members of theDrosophila nannoptera species group. Results indicate that visual and auditory signals do not play a significant role in mating success inDrosophila acanthoptera andD. species W.Acknowledgments. This study was supported by a Division of Research Resources-National Institute of Health, Minority Biomedical Support grant (RR 07152-04) awarded to M.C.J. The grant provides a stipend for E.S.G. who is completing requirements for her Master of Science degree in Biology. Send reprint requests to M.C.J.     

Variability within and between strains for mating behaviour parameters inDrosophila pseudoobscura

Résumé Chez un caryotype donné deDrosophila pseudoobscura on constate dans quelques lignées plus de variabilité dans la durée du comportement sexuel précédant l'accouplement que dans la durée de celui-ci.

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Supported by the Commonwealth of Australia Scholarship and Fellowship Plan.     

Evidence for the participation of the preoptic area in male mating behaviour

Zusammenfassung Bei Ratten kann durch kleine, umschriebene elektrolytische Läsionen basal in der präoptischen Area das typische Verhalten der männlichen Tiere im Coitus sowohl beim Weibchen als auch beim Männchen ausgelöst werden. Diese Reaktionen werden offenbar durch einen rein neuralen Mechanismus hervorgerufen und scheinen in weitem Masse unabhängig von der Stimulation durch Sexualhormone.     

Sexual isolation betweenDrosophila melanogaster females andD. simulans males. Male mating propensities versus success in hybridization

Genetic variation has been found in males of aD. simulans population for their eagerness to hybridize withD. melanogaster females. In a search for traits involved in this hybridization, males ofD. simulans were tested for mating speed and sexual vigour. Between-male differences were detected in both sexual traits, but no relationship was noticed between them, nor with the frequency of hybridization. Thus male mating propensities appear to be unrelated to the breakdown of sexual isolation between these sibling species.     

Can we predict the mating pattern of Drosophila females from the sperm length distribution in males?

In order to test the validity of the prediction of the mating pattern of females from the sperm length distribution in males, three species of Drosophila were analysed. Males in the three species are equally polygynous but females differ in the level of polyandry. A 'low recurrence polyandry' is observed in the sperm dimorphic species D. affinis while a 'high recurrence polyandry' is observed in the sperm monomorphic species D. latifasciaeformis and D. littoralis. These results are consistent with the hypothesis proposed previously that sperm dimorphism in males can only be maintained by a selective alternative in females (i.e. facultative female polygamy), whereas a stricter mating system (e.g. 'obligatory' polyandry) should only result in sperm monomorphism irrespective of the absolute value of sperm length.     

Superoxide dismutase and life span ofDrosophila melanogaster

Summary Comparison of superoxide dismutase activity in homogenates of wild and vestigial strains ofD. melanogaster revealed a lower enzyme activity in the short-living vestigial strain.Acknowledgments. We are indebted to Prof. M. Olszewska for giving us fly specimens. This work was partly supported by the project No. R. III. 13. 2. 4.     

Drastic changes in the mating behaviour of male rats following lesions in the junction of diencephalon and mesencephalon

Zusammenfassung Umfangreiche Läsionen im Grenzgebiet zwischen Mittelhirn und Zwischenhirn bei Ratten führten zu stark erhöhter sexueller Aktivität. Die Ruheperioden nach der Ejakulation waren abnorm kurz, was die Zahl der Ejakulationen während des Versuches stark erhöhte. Auch 6 Monate nach Operation konnte kein Rückgang des Zustandes festgestellt werden.     

The cell cycle of an established line ofDrosophila melanogaster cells in vitro

Riassunto La durata media delle fasi del ciclo cellulare (G₁, S e G₂) e del tempo di generazione totale (G _T ) in una linea stabilizzata di cellule diDrosophila melanogaster risulta essere rispettivamente di 1.8, 10.0, 7.2 e 18.8 ore.     

Behaviour and random mating

Résumé Des expériences portant sur le comportement sexuel chez plusieurs espèces, telles que la drosophile et la souris nous montrent que l'hypothèse qu'elles s'accouplent par hasard, hypothèse dont on fait état assez fréquemment dans la génétique des populations, n'est valable dans cadre des populations naturelles qu'avec de sérieuses restrictions.

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This work was supported by the Australian Research Grants Committee.