Friday, October 28, 2011

Annotated Bibliography

Abbott JK & Morrow EH. 2011. Obtaining snapshots of genetic variation using hemiclonal

analysis. in press.

The article provides a review of the current literature on hemiclonal analysis, as well as discussing the value of hemiclone analysis and potential applications of current hemiclonal systems to include molecular and genomic studies. The article also provides a detailed description of the artificial hemiclone production in Drosophila melanogaster and the background of the system. The article includes a summary of the results of previous studies, including many on sexual selection and sexual conflict. These results demonstrate the value of hemiclones in the study of genetic variation in these matters.

Anderson WW, Yong-Kyu K & Gowaty PA. 2007. Experimental constraints on mate

preferences in Drosophila pseudoobscura decrease offspring viability and fitness in mated pairs. Proceedings of the National Academy of Science 104(11): 4484-4488.

The study looked at the effects of social constraints on expression of mate preferences and the effects on offspring viability and reproductive success for both males and females. The experiment used mate preference arenas designed to allow free movement of the focal fly, eliminate intrasexual combat, eliminate intersexual coercion, and allow for visual, olfactory and auditory contact while preventing tactile contact. Focal flies were then mated with either their preferred or non-preferred choice when they met the preference criteria to look at the effects on offspring viability. The study found a significant difference in offspring viability with a higher level of reproductive success seen when flies were mated with their preferred individual. This study appears to show that there is an effect on offspring as a result of mate choice demonstrating the value of a more complete understanding of sexual selection.

Bakker TCM & Pomiankowski. 1995. The genetic basis of female mate choice. Journal of

Evolutionary Biology 8:129-171.

The article is a review of the evidence of genetic variation in both male and female mate preference. The review lists a range of evidence for genetic variation of mate preference including the genetic differences seen between species and isolated races which show that preferences can evolve and have shown genetic variation in the past. The article also talks about the evidence of genetic variation within populations including both discrete and quantitative genetic effects. The presence of genetic covariance between mate preference and sexual traits in the opposite sex are also discussed. The review demonstrates the incomplete understanding of the genetic basis of mate choice and the value of further research.

Candolin U. 2003. The use of multiple cues in mate choice. Biological Reviews 78:575-595.

The article provides a review of the use of multiple cues that females use during mate selection and the various hypotheses on why this occurs. The review also provides new categorisation which is based on adaptiveness of the preference along with the information contained within the cue. Previous studies have suggested that multiple cues are either uninformative of attractiveness cues which occur alongside a viability indicator either as remains of past selection pressures or to either facilitate detection or improve signal reception. The review also states that, in contrast to this, there is substantial evidence that suggests multiple cues provide additional information and indicate general mate quality or allow for differences in mate preferences. The article demonstrates that there is an unclear understanding of the value of multiple signals, highlighting the need for more research in the area.

Cotton S, Fowler K & Pomiankowski A. 2004. Do sexual ornaments demonstrate heightened

condition-dependent expression as predicted by the handicap hypothesis? Proceedings of The Royal Society B: Biological Sciences 271:771-783.

The article provides a review of 65 different experiments on sexual ornaments and contains an analysis of their methods to determine the viability of the results. It was observed that, while many of the studies looked at found that sexual ornaments to be condition dependant, most of the experiments were poorly designed. The authors then compiled a list of three aspects that are needed in any future studies of condition-dependence of sexual ornaments. These three aspects were: making a comparison of traits using non-sexual trait controls; control of body size variation; and experimental conditions that starch over a range of levels, not simply two extremes. The review demonstrates that many of the previous studies done on the condition-dependence of sexual ornaments and gives a clear listing of what should be included in future research.

Ewing AW. 1964. The influence of wing area on the courtship behaviour of Drosophila

melanogaster. Animal Behaviour 12:316-320.

The study looked at the effects of wing area on courtship success in Drosophila melanogaster. Wing area was altered in three ways; altering temperature during development, selective breeding and amputation. Standards were determined for removing a set percentage of the wing based on veins within them. The study found there to be an apparent linear relationship between wing area and extrapolated that approximately 80% of sexual stimulation is provided by wing vibration under normal conditions.

Greenspan RJ & Ferveur JF. 2000. Courtship in Drosophila. Annual Review of Genetics 34:205-


The article discusses courtship behaviour and it various components as seen in Drosophila. The paper covers courtship form the gene level and looks at the results of different experimental approaches while attempting to outline the genes acting on the brain which produce the species-specific courtship ritual. It also provides a detailed review of the species mate recognition system and the various types of signalling involved in it.

Hall JC. 1994. The mating of a fly. Science 264(5166):1702-1714.

The article investigates the various forms of pleiotropic mutations that lead to defective courtship. By observing mutations in “courtship genes” responsible for components of sensory, learning or rhythm mutations that cause defective courtship attention has been drawn to components of male and female actions that have otherwise been unnoticed. The article also discusses a variety of genes involved in gender determination including two genes which affect the sex of flies under various conditions. These mutations result in flies for which gender is determined by the environment in which they are raised. The article provides a highly detailed description of courtship behaviours in Drosophila while also demonstrating the effects of environment and genetic interactions in courtship and sex-related behaviours and genes.

Jennions MD & Petrie M. 1997. Variation in mate choice and mating preferences: A review of

causes and consequences. Biological Reviews 72:283-327.

The review focused on the variation seen among females for mate preferences, and defined mate preferences to be the sensory and behavioural properties that lead to decisions about mate choices. The article defined the two properties of mating preferences to be the order in which individuals rank as prospective mates and the effort and individual invests in mate assessment. The review also discussed the importance of studying variation in female mate preferences and comments on the lack of research currently done on the topic.

Kowalski S, Aubin T & Martin, JR. 2994. Courtship song in Drosophila melanogaster: a

differential effect on male-female locomotor activity. Canadian Journal of Zoology 82(8):1258-1266.

The study focused on the effect of male auditory signalling during courtship and its effects on female locomotor activity. A video-tracking system was used during courtship to allow for quantification of movement during the trials. The study found that locomotor activity was only altered when the courtship song was accompanied by the presence and movement of a male, indicating that auditory signalling alone was not sufficient to induce courtship effects in females.

Krupp JJ, Kent C, Billeter JC, Azanchi P, So AKC, Schonfeld JA, Smith BP, Lucas C & Levine

JD. 2998. Social experience modifies pheromone experience and mating behaviour in male Drosophila melanogaster. Current Biology 18:1373-1383.

The study looked at the affects of social context on chemical signalling in Drosophila melanogaster. It had previously been shown that a variety of behaviours in D. melanogaster are influenced by social interaction including courtship, which is mediated by pheromone signalling. They found that pheromone synthesis occurs on a functional circadian clock and that the transcription of certain genes involved in pheromone production changes during the day as a result of these patterns. It was found that mixing genotypes altered gene transcription and patterns of pheromone accumulation of the cuticle .This demonstrates the ability to alter the chemosensory signalling of D. melanogaster based on the social context they are raised in.

Narraway C, Hunt J, Wedell N & Hosken DJ. 2010. Genotype-by-environment interactions for

female preference. Journal of Evolutionary Biology 23(12):2550-2557.

The study looked at the interaction of environment with genotype and its effects on mate choice in female Drosophila melanogaster. They used a no choice design and iso-female lines in their experiments. It was discovered that there were genotype-by-environment interactions seen in female mate preference but that the level of this interaction varied for different female genotypes.

Rosvall KA. 2011. Intrasexual competition in females: evidence for sexual selection.

Behavioural Ecology

The article reviews the multiple hypotheses on whether traits influencing female-female competition are sexually selected. The article discusses the various reasons for the existence of intrasexual competition and determines whether each one is sexually selected or the result of natural section. It does so by defining ­­­traits that influence competition for mates to be sexually selected, while anything to do with fecundity or offspring survival. The article also concluded that female compete more for higher quality mates than they do for number of mates.

Rybak F, Sureau G & Aubin T. 2002. Functional coupling of acoustic and chemical signals in

the courtship behaviour of the male Drosophila melanogaster. Proceedings of the Royal Society B: Biological Sciences 269:659-701.

The study looked at the effects of chemosensory and acoustic signalling on female mate choice in Drosophila melanogaster. Females were presented with males who were able to emit both signals normally, were deprived of both signals or were lacking in one or the other. The study found that males who were unable to emit both chemical and auditory signals were unable to mate, while a red reduced the frequency of courtship success. The study does not look at differences in preference across females and the varying degrees to which a reduction in either chemosensory or acoustic signalling may be affected by them.

Sharma MD, Tregenza T & Hosken DJ. 2010. Female mate preferences in Drosophila simulans:

evolution and costs. Journal of Evolutionary Biology 23:1672-1679.

The study looked at the evolution of mate preferences using Drosophila simulans and females selecting for ebony-covered males. Females who showed a preference for ebony-males were mated and their offspring were then observed. An increase in female selection for ebony-males was seen showing that there is a genetic variation for female mate preferences and that this preference evolves and changes. The study does not comment on the potential environmental influences on female mate preferences.

Sunday, October 23, 2011

Friberg, U. 2006. Male perception of female mating status: its effect on copulation duration and male and female fitness in Drosophila melanogaster. Anim. Behav. 72:1256-1268.

In this study, Friberg justifies the idea that the risk of sperm competition in male Drosophila melanogaster is highly influenced by female mating status. Males can assess female mating status by inspecting the female cuticular hydrocarbon (CH) profile, which changes when females mate. Friberg tests this by manipulating female CHs by transferring from either virgin or mated females to virgin females. The results show that males copulated significantly longer with virgin females that had been coated with CHs from mated females compared to virgin females who had been coated with CHs from other virgin females. In addition, Friberg found that male sperm defense is elevated when males perceive their partner as mated. This study proves to be important to future studies in female mate choice examining the social experiences and housing experiences of mated and nonmated females. More specifically, if virgin females housed with mated females have different male preferences than virgins housed together.

Friberg, U. & Arnqvist, G. 2003. Fitness effects of female mate choice: preferred males are detrimental for Drosophila melanogaster females. J. Evol. Biol. 16: 797-811.

The authors investigated female fitness and how it is affected by reproducing with large or small males, using two different male densities and male size as a proxy for male attractiveness. The results indicated that females housed with large males had reduced lifespans and aged at an accelerated rate compared with females housed with small males. In addition, increased male density depressed female fitness even further. The authors suggest that female mate choice in Drosophila melanogaster is, in part, a by-product of sexual conflict over the mating rate. This study is relevant to my research as it involves determining size differences in males by thorax length, something which I may use as the variable for female choice. The study also contains relevant information regarding female mate choice as a function of male size and if this is correlated with direct benefits, indirect benefits, and female fitness

Cook, R. & Cook, A. The attractiveness to males of female Drosophila melanogaster: Effects of mating, age and diet. Anim. Behav. 23: 521-526.

The authors studied the attractiveness of female Drosophila melanogaster to males using decapitated females, because decapitated females show minimal behavioural response. Decapitated females, which will survive for many hours, provide a relatively constant stimulus to the male, since she remains stationary. Such females do not extrude their genitalia in response to courtship. The results show that the attractiveness of virgin females varied with age, being at a maximum on the day of eclosion, and declining after. Even though decapitated inseminated females do not extrude their genitalia they received less courtship than decapitated virgin females. The authors also examined the effect of protein vs. sucrose diets on the attractiveness of females. A sucrose diet was found to render both virgin and inseminated decapitated female more attractive to males. This study presents relevant information on courtship and female receptivity to males based on mating status, which is useful for my research.

Aigaki, T. & Ohba, S. Effect of mating status on Drosophila virilis lifespan. Exp. Gerontol. 4:267-278.

Aigaki and Ohba studdeid the effect of mating status on Drosophila virilis by looking at the lifespan of virgin males and females, population density, and sex ratio. In addition, the authors examined lifetime egg production between virgin and nonvirgin females. The effect of virginity on lifespan was different between the sexes. In all cases lengthening of female lifespan and shortening of male lifespan was observed as an effect of virginity. At a high sex ratio, females and males have similar mean lifespans. At a low ratio, mean female and mean male lifespans were insignificantly insignificant. Lifetime egg production for a mated female was found to be greater than for a virgin female. This study is relevant to my research on mating status of nonvirgin and virgin females and how social experience and mating history affects courtship, copulation, and fecundity.