The white gene of Drosophila melanogaster has been extensively studied, yet it is still not understood how its ectopic overexpression induces male-male courtship. To investigate the cellular basis of this behavior, we examined the sexual behavior of several classes of mutants. We find that male-male courtship is seen not only in flies overexpressing the white gene, but also in mutants expected to have mislocalized White protein. This finding confirms that mislocalizing White transporter in the cells in which it is normally expressed will produce male-male courtship behaviors; the courtship behavior is not an indirect consequence of aberrant physiological changes elsewhere in the body. Male-male courtship is also seen in some mutants with altered monoamine metabolism and deficits in learning and memory, but can be distinguished from that produced by White mislocalization by its reduced intensity and locomotor activity. Double mutants overexpressing white and with mutations in genes for serotonergic neurons suggest that male-male courtship produced by mislocalizing White may not be mediated exclusively by serotonergic neurons. We also find decreased olfactory learning in white mutants and in individuals with mutations in the genes for White's binding partners, brown and scarlet. Finally, in cultured Drosophila and mammalian cells, the White transporter is found in the endosomal compartment. The additional genes identified here as being involved in male-male courtship increase the repertoire of mutations available to study sexual behavior in Drosophila.

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We report here the first successful use of embryonic nuclear transfer to create viable adult Drosophila melanogaster clones. Given the generation time, cost effectiveness, and relative ease of embryonic nuclear transplant in Drosophila, this method can provide an opportunity to further study the constraints on development imposed by transplanting determined or differentiated nuclei.

ObjectivesAnecdotal evidence suggests that organ donation from deceased donors referred to the Coroner/Procurator Fiscal (PF) could be increased if all followed best practice. The aim of this prospective audit was to establish how referrals affected organ donation and to develop evidence-based guidelines to ensure that organ donation can be facilitated safely without interfering in the Coroner/PF's investigative process.DesignProspective audit.SettingAll acute National Health Service Hospitals in the UK where deceased organ donation was considered.Participants1437 deceased patients who met the eligibility criteria for organ donation and were referred to Coroner/PF.Main outcome measuresNumber of cases where permission for transplantation was given, number of organs where permission was refused and number of organs which might have been transplanted if all had followed best practice.ResultsFull permission for organ retrieval was given in 87% cases and partial permission in 9%. However, if full permission had been given where no autopsy was performed or restrictions seemed unjustified, up to 77 organs (22 lungs, 22 kidneys, 9 pancreases, 9 livers, 8 hearts and 7 small bowels) could have been available for transplant.ConclusionsCoroners/PFs and their officers show strong support for transplantation but improvement in practice could result in a small but significant increase in life-saving and life-enhancing transplants.

Genomic imprinting is a process that genetically distinguishes maternal and paternal genomes, and can result in parent-of-origin-dependent monoallelic expression of a gene that is dependent on the parent of origin. As such, an otherwise functional maternally inherited allele may be silenced so that the gene is expressed exclusively from the paternal allele, or vice versa. Once thought to be restricted to mammals, genomic imprinting has been documented in angiosperm plants (J.L. Kermicle. 1970. Genetics, 66: 69-85), zebrafish (C.C. Martin and R. McGowan. 1995. Genet. Res. 65: 21-28), insects, and C. elegans (C.J. Bean, C.E. Schaner, and W.G. Kelly. 2004. Nat. Genet. 36: 100-105.). In each case, it appears to rely on differential chromatin structure. Aberrant imprinting has been implicated in various human cancers and has been detected in a number of cloned mammals, potentially limiting the usefulness of somatic nuclear transfer. Here we show that genomic imprinting associated with a mini-X chromosome is lost in Drosophila melanogaster clones.