Matthew Cobb

The University of Manchester · Faculty of Life Sciences

The most studied pheromone in Drosophila melanogaster, cis-Vaccenyl Acetate (cVA), is synthesized in the male ejaculatory bulb and transferred to the female during copulation. Combined with other chemicals cVA can modulate fly aggregation, courtship, mating and fighting. We explored the mechanisms underlying both cVA biosynthesis and emission in ma...

The most studied pheromone in Drosophila melanogaster, cis-Vaccenyl Acetate (cVA), is synthesized in the male ejaculatory bulb and transferred to the female during copulation. Combined with other chemicals cVA can modulate fly aggregation, courtship, mating and fighting. It is not detected on the cuticle of isolated males and is only released by ma...

Pheromones are chemical signals that induce innate responses in individuals of the same species that may vary with physiological and developmental state. In Drosophila melanogaster , the most intensively studied pheromone is 11- cis -vaccenyl acetate (cVA), which is synthezised in the male ejaculatory bulb and is transferred to the female during co...

Amount of cVA detected on and inside flies Box plots indicate the amount of cVA (ng/fly) detected on virgin and recently mated male and female flies (n = 9 − 17). We used solvent extraction over two periods: the 20 min-long extraction revealed the cVA present on the fly cuticle, whereas the 24 h-long solvent extraction (at 40 °C) allowed us to extr...

Cuticular hydrocarbons on eggs Comparison of total CHs amount on eggs laid by the females either one day (+1D) or 10 days (+10D) after mating (n = 10; 50 pooled eggs were extracted for each female). For more details, see Fig. 1.

Post-mating effect Courtship frequency (A) and latency (B) were measured in focal males derived from +1D and +10D eggs in the presence of 0 or 600 ng cVA. For more details see Figs. 1 and 4.

Effect of cVA added on eggs Courtship frequency (A) and latency (B) were measured in focal males dervived from control +1D eggs (filled bars), or of washed +1D eggs (empty bars), some of which were covered with a synthetic cVA solution (shaded bars). All eggs were placed on plain food and resulting males were tested with 0 or 600 ng cVA. For more d...

Identification of a critical period Courtship latency was measured in focal males derived from control eggs (filled bars) or from eggs washed at different times after egg-laying (AEL; +10, +20, +48, +72 h; empty bars) with 600 ng cVA (A) or no cVA (B). For more details see Figs. 1 and 5.

Whole dataset The dataset is organised according to figures.

Egg and food manipulation Courtship latency was measured in focal males each paired with a beheaded female in the presence of 0, 350 or 600 ng cVA. Focal males were derived from +1D eggs either with no treatment (filled bars), or from washed eggs raised either on plain food (empty bars), or on food seeded with WT2 eggs (light gray bars), or on cVA-...

Larval responses to cVA Individual larvae produced by +1D (A) or +10D (B) control eggs were placed on an agar plate with two food sources at opposite sides. These were either plain food (PF) or PF with the addition of 1 ng –10 μg of cVA. N = 50 for each comparison. The first food source reached by each larva was noted. There were no significant dif...

Background The insect cuticle covers the whole body and all appendages and has bi-directionnal selective permeability: it protects against environmental stress and pathogen infection and also helps to reduce water loss. The adult cuticle is often associated with a superficial layer of fatty acid-derived molecules such as waxes and long chain hydroc...

Principal cuticular hydrocarbon levels in various desat1 transgenic females CHs were measured in transgenic female progeny of mothers carrying a UAS-desat1-IR transgene (IR) and fathers either carrying each desat1 putative regulatory region fused with Gal4 (PRR-Gal4) corresponding to each desat1 transcript (RA, RC, RE, RB, RD, RDiO), or the complet...

Principal cuticular hydrocarbon levels in females of selected lines between F18 and F57 In F18, F19, F55 and F57 females of various selected lines, the absolute (Q in µg; A) and relative (%; B) amounts of desaturated CHs (alkenes; top of each panel) and of linear saturated CHs (alkanes; bottom) were measured. N = 7–38. For statistics, CHs and lines...

Raw data for all figures and supplementary figures

Survival in flies of different ages and mating statuses We determined the survival curve of virgin (dashed lines) and mated (plain lines) females (A) and males (B) of different ages (measured at the beginning of the desiccation experiment): 1 day old (cyan), 3–4 day-old (green) and 7–8 day-old (magenta). The LT50 (C) and slope (D) corresponding to...

Survival in F1–F6 males of selected lines Male flies were selected using the experimental procedure described in Figs. 1 and 2. (A) For each generation (F1 to F6), the curves represent the cumulative lethality measured in various genotypes (dashed = Di2, cyan = 77S selected lines pooled, magenta = backcross between 77S females and unselected siblin...

Principal cuticular hydrocarbon levels in flies of selected lines after relaxation of selection CH levels were measured in F7, F8 and F9 females and in F8 males separately in the six 77S lines (77S0–77S5) produced by selection for desiccation resistance (Fig. 4). Absolute (Q in µg; A) and relative (%; B) amounts of desaturated CHs (alkenes; top of...

Fecundity and sex-ratio in the progeny of selected lines at F57 The progeny of individual mated females from the control Di2 line and from selected (77S1−5) and reselected (77S-Sel1-3) lines for increased desiccation resistance was counted to determine their respective fecundity (number of adults left) and the sex ratio (Female:Male). Data were tes...

Fecundity and sex ratio in the progeny of various desat1 transgenic females Total adult progeny (A, C) and progeny sex ratio (B, D) of individual mated females of experimental (A, B) and control (C, D) genotypes (see Fig. S5 legend). N = 7–12 For more information on statistics and lines, see legends to Figs. 2 and 7 & Fig. S5.

Background. The insect cuticle covers the whole body and all appendages and has bi-directionnal selective permeability: it protects against environmental stress and pathogen infection and also helps to reduce water loss. The adult cuticle is often associated with a superficial layer of fatty acid-derived molecules such as waxes and long chain hydro...

Background. The insect cuticle covers the whole body and all appendages and has bi-directionnal selective permeability: it protects against environmental stress and pathogen infection and also helps to reduce water loss. The adult cuticle is often associated with a superficial layer of fatty acid-derived molecules such as waxes and long chain hydro...

In 1961, the National Institutes of Health (NIH) began to circulate biological preprints in a forgotten experiment called the Information Exchange Groups (IEGs). This system eventually attracted over 3,600 participants and saw the production of over 2,500 different documents, but by 1967, it was effectively shut down following the refusal of journa...

In September 1957, Francis Crick gave a lecture in which he outlined key ideas about gene function, in particular what he called the central dogma. These ideas still frame how we understand life. This essay explores the concepts he developed in this influential lecture, including his prediction that we would study evolution by comparing sequences.

This speculative Essay explores the consequences of the imagined premature death of Oswald Avery, who in 1944 provided evidence that genes are made of DNA. Four imaginary alternate routes to the genetic function of DNA are outlined, each of which highlights different aspects of the actual process of discovery.

We studied the electrophysiological activity of two classes of Drosophila melanogaster larval olfactory sensory neurons (OSNs), Or24a and Or74a, in response to 1s stimulation with butanol, octanol, 2-heptanone, and propyl acetate. Each odour/OSN combination produced unique responses in terms of spike count and temporal profile. We used a classifier...

The announcement of the discovery of messenger RNA (mRNA) and the cracking of the genetic code took place within weeks of each other in a climax of scientific excitement during the summer of 1961. Although mRNA is of decisive importance to our understanding of gene function, no Nobel Prize was awarded for its discovery. The large number of people i...

Allelic variation at 4 loci in the human olfactory receptor gene OR7D4 is associated with perceptual variation in the sex steroid-derived odorants, androstenone, and androstadienone. Androstadienone has been linked with chemosensory identification whereas androstenone makes pork from uncastrated pigs distasteful ("boar taint"). In a sample of 2224...

Seventy years ago, Oswald Avery and his colleagues from the Rockefeller Institute published the first evidence that genes are made of DNA. Their discovery was received with a mixture of enthusiasm, suspicion and perplexity. In this article, I trace the reasons for these different responses, and show how we need to revise our usual explanations of w...

In 1953, Watson and Crick not only described the double-helix structure of DNA, but also embraced the idea that genes contained a code that expresses information and thereby changed our view of life. This article traces how these ideas entered biological thinking and highlights the connections between different branches of science at the time, expl...

The scientific identification of the key components of sexual reproduction - eggs and sperm - took place during an amazing decade of discovery in the 1660s and 1670s. The names of many of the people involved are now forgotten, and yet their work, and the difficulties they faced and the conflicts they endured, resonate strongly to the present day. D...

The sensory and genetic bases of incipient speciation between strains of Drosophila melanogaster from Zimbabwe and those from elsewhere are unknown. We studied mating behaviour between eight strains - six from Zimbabwe, together with two cosmopolitan strains. The Zimbabwe strains showed significant sexual isolation when paired with cosmopolitan mal...

Supplementary Info

Electrophysiological responses of identified larval OSNs. Larvae from eight single Or strains (Or45b – Or83a) were stimulated with 19 odors. Responses are given as mean (± SEM) firing rates of single OSNs above an objective response criterion. Percentages indicate the proportion of odor presentations that elicited a response above criterion when st...

Variable responses for a given odor-OSN combination are not a function of stimulus flow rate or concentration. Individual w1118 larvae (1–4) were stimulated with 2% butanol at three different flow rates (A) or 0.2% butanol at 30 ml/s (B). In all cases, butanol induced qualitative response variability; sometimes the OSNs responded, sometimes they di...

Electrophysiological responses of identified larval OSNs. Larvae from nine single Or strains (Or1a – Or45a) were stimulated with 19 odors. Responses are given as mean (± SEM) firing rates of single OSNs above an objective response criterion. Percentages indicate the proportion of odor presentations that elicited a response above criterion when stim...

The Drosophila larva possesses just 21 unique and identifiable pairs of olfactory sensory neurons (OSNs), enabling investigation of the contribution of individual OSN classes to the peripheral olfactory code. We combined electrophysiological and computational modeling to explore the nature of the peripheral olfactory code in situ. We recorded firin...

The ESF-EMBO conference 'Functional Neurobiology in Minibrains' was held in the sunny Spanish seaside resort of Sant Feliu de Guíxols in October 2010. The meeting brought together approximately 100 scientists to discuss the interactions between neurobiology and robotics.

![Figure][1] Many larval stages of insects that metamorphose – caterpillars, maggots and the like – are shaped like a tube with the gut running through the middle. In a recent hi-tech study, a group of US researchers led by Michael Simon of Tufts University set out to discover how

![Figure][1] Increased atmospheric CO2 levels will have a major impact on marine life, in particular on corals and molluscs, through the effects of ocean acidification on calcification. A recent international collaboration by researchers from Australia, Canada and the USA suggests that non-

![Figure][1] Damselflies show abrupt, darting flight, which is the envy of aero-engineers. This amazing ability is used both to capture prey and, by males, to establish territories that can attract females. Insects are ectothermic, so maintaining this flying ability in the face of fluctuating

Most living organisms use pheromones for inter-individual communication. In Drosophila melanogaster flies, several pheromones perceived either by contact/at a short distance (cuticular hydrocarbons, CHs), or at a longer distance (cis-vaccenyl acetate, cVA), affect courtship and mating behaviours. However, it has not previously been possible to prec...

The behavioral role of dipteran cuticular hydrocarbons (CHCs) was first established nearly 40 years ago, in four articles on the behavior and chemistry of the housefly, Musca domestica, that came out of the USDA laboratory in Gainesville (Florida). Following Rogoff et al.(1964), Mayer and James (1971) showed that the non-polar lipid fraction of hou...

![Figure][1] Orchids can be highly deceptive. About 10,000 nectarless orchid species deceive insects into visiting them by imitating either the scent of a nectar-bearing flower or, more dramatically, the shape and pheromones of an insect of the opposite sex. A new twist to this story has

![Figure][1] Birds of the crow family are widely considered to be intelligent animals and the New Caledonian crow has been shown to be as proficient in its use of tools as most of the great apes. In a recent article in Proceedings of the National Academy of Sciences of the USA , the aptly

![Figure][1] Ants primarily use chemical communication to identify themselves as members of the colony and to indicate their reproductive status. This system can be exploited by parasites, which imitate the chemicals produced by the ants and thereby gain access to the nest. In the case of the

Charles Darwin's 1859 book On the Origin of Species is much referenced, especially in this double anniversary year. But, does anyone still read it? And, if so, what is the book itself like as a text? We have asked biologists from a range of fields evolutionary biologists, but also geneticists, ecologists, paleontologists and molecular biologists to...

![Figure][1] It is not often that a single, non-experimental observation can undermine our view of what happened hundreds of millions of years ago, but that is what happened 780 m below the surface of the Atlantic, around the Bahamas. A group of US and Australian marine biologists, led by

The exact nature of the olfactory signals that arrive in the brain from the periphery, and their reproducibility, remain essentially unknown. In most organisms, the sheer number of olfactory sensory neurons (OSNs) makes it impossible to measure the individual responses of the entire population. We measured the individual in situ electrophysiologica...

Behavioural preferences of Drosophila larvae are often measured in a simple ‘plate test’, in which groups of larvae are allowed to migrate on an agar surface in response to variation in a stimulus. We investigated the behaviour of individual larvae in an olfactory test, alone and in groups. Using mixed groups of responsive and nonresponsive larvae,...

The Tribolium castaneum genome sequence reveals a large number of odorant receptor (Or) genes compared to those found in other insects whose olfactory genomes have been studied-341 Or genes and pseudogenes, encoding 259 intact odorant receptor proteins. An RT-PCR study of larvae and adults revealed that only 145 (64%) of 233 genes with successful g...

![Figure][1] In many species of fly, females are attracted to lay eggs where other females have previously laid. The activity of large numbers of larvae makes the food more edible, often by increasing the rate of substrate decay, thereby aiding larval growth and survival. In the housefly,

In 1956, Margaret Bastock published the first demonstration that a single gene could change a behaviour pattern. A Ph.D. student with Niko Tinbergen, Bastock's work was partly inspired by discussions between Tinbergen and the American evolutionary biologist, Ernst Mayr. In this essay, the genesis of Bastock's work is outlined, including reference t...

Sexual behavior requires animals to distinguish between the sexes and to respond appropriately to each of them. In Drosophila melanogaster, as in many insects, cuticular hydrocarbons are thought to be involved in sex recognition and in mating behavior, but there is no direct neuronal evidence of their pheromonal effect. Using behavioral and electro...

The olfactory response of maggots (the larvae of cyclorrhaphous flies) and its neuroanatomical basis have been a subject for scientific investigation since the 17th century, preoccupying both fundamental and applied scientists. Despite its apparently arcane nature, the subject raises a series of major neurobiological problems, in particular, the re...

Two hundred years ago, biologists did not recognize that there was such a thing as 'heredity'. By the 1830s, however, insights from medicine and agriculture had indicated that something is passed from generation to generation, creating the context for the brilliant advances of Mendel and Darwin. Recent work on the history and philosophy of science...

Paw preferences in domestic dogs were studied using three different behavioural tests, recording frequency, duration and latency of paw use. No overall population tendency to right- or left-paw preference was seen on any of the tests, nor could a sub-population of handed dogs be detected. This failure to replicate previous reports that male dogs te...

Reproductive conflicts are particularly intense in queenless ants because colonies are made up of totipotent workers, all potentially able to mate and produce female offspring. After a gamergate (a mated egg-laying worker) dies, aggressive interactions determine her replacement. In Diacamma, the single gamergate systematically mutilates newly emerg...

0960-9822 (Print) Comparative Study Letter

In order to reveal aspects of olfactory coding, the effects of sensory adaptation on the olfactory responses of first-instar Drosophila melanogaster larvae were tested. Larvae were pre-stimulated with a homologous series of acetic esters (C3-C9), and their responses to each of these odours were then measured. The overall patterns suggested that met...

In the present paper, the larval development of the queenless ponerine ant Diacamma ceylonense is studied. Four instars were identified on the basis of cuticular processes – tubercles and spinules – which show discontinuous variation during growth and provide precise and reliable external morphological criteria for instar discrimination. In the fir...

We summarize data showing that there is population structure in African populations of Drosophila from the melanogaster-simulans complex. In D. melanogaster, population structuring is found at individual loci, but is obscured by population structuring for large inversions that simultaneously affect several loci. In D. simulans, molecular polymorphi...