While mitochondria have long been understood to be critical to cellular function, questions remain as to how genetic variation within mitochondria may underlie variation in general metrics of ...organismal function. To date, studies investigating links between mitochondrial genotype and phenotype have largely focused on differences in expression of genes and physiological and life‐history traits across haplotypes. Mating display behaviours may also be sensitive to mitochondrial functionality and so may also be affected by sequence variation in mitochondrial DNA, with consequences for sexual selection and fitness. Here, we tested whether the pre‐copulatory mating success of male fruit flies (Drosophila melanogaster) varies across six different mitochondrial haplotypes expressed alongside a common nuclear genetic background. We found a significant effect of mitochondrial haplotype on our measure of competitive mating success, driven largely by the relatively poor performance of males with one particular haplotype. This haplotype, termed ‘Brownsville’, has previously been shown to have complex and sex‐specific effects, most notably including depressed fertility in males but not females. Our study extends this disproportionate effect on male reproductive success to pre‐copulatory aspects of reproduction. Our results demonstrate that mutations in mitochondrial DNA can plausibly affect pre‐copulatory mating success, with implications for future study into the subcellular underpinnings of such behaviours and the information they may communicate.
When male fruit flies possessing one of six different focal mitochondrial haplotypes competed for copulations with females against a common strain of non‐focal males, flies with the “BRO” (or Brownsville) haplotype were significantly less successful than their counterparts.
Males display phenotypic characteristics that may be associated with their quality, allowing non-random mating and post-copulatory female choice. In the damselfly Calopteryx haemorrhoidalis asturica ..., males have a conspicuous pink colouration in the underside of abdominal segments 8–10, which they exhibit during pre- and post-copulatory courtship. We hypothesized that this colouration functions to increase male mating success and/or to elicit females to oviposit. We estimated mating and oviposition success of 27 males, and on the following day, treated males had their segments 8–10 painted black and control males the seventh segment. We recorded the number of male–male fights and courtships, whether the courtship ended in copulation, and whether the female remained in the territory and laid eggs. Our results indicate that the mating success of male C. h. asturica was not significantly affected by the removal of the pink colouration of the abdominal tip, but this colouration clearly affected their success in enticing females to oviposit. Courtship frequency, fat content and muscle mass were positively correlated to male mating rate, and the number of aggressive encounters was negatively correlated. Our study yields experimental evidence for the function of pink colouration of male C. h. asturica , in the context of post-copulatory sexual selection.
Inhalant misuse is a worldwide problem, especially among adolescents. Toluene is the most widely misused inhalant. One hallmark of adolescence is the emergence of sexual behaviour, which can be ...affected by drug use. The aim of this study was to analyse the effects of toluene inhalation on different aspects of male rats’ sexual behaviour using a binge pattern of exposure in adolescent rats. Male Wistar rats were individually exposed to air or 6,000 ppm toluene for 30 min (acute exposure; n = 8 each) or twice a day for 12 days (repeated exposure; n = 9 each) in static exposure chambers. Independent groups of sexually experienced, adolescent rats (postnatal day 63, PN63) were tested after acute toluene exposure for copulation, sexual incentive motivation or noncontact erections. Sexually naïve, adolescent rats (PN45–59) were repeatedly exposed to toluene and tested for sexual behaviour after completing the 1st, 3rd, 5th, 7th, 9th, 11th and 13th exposure sessions. Acute toluene exposure impaired copulatory performance, diminished sexual incentive motivation and delayed noncontact erection occurrence in sexually experienced rats. Repeated toluene exposure during adolescence completely inhibited the onset of copulatory behaviours in sexually naïve rats, at the time at which they should have appeared. However, once the inhalant exposure ended, copulatory responses appeared gradually, and animals attained a typical, stable copulatory pattern. In conclusion, acute toluene exposure impairs sexual behaviour in young, sexually experienced animals, while repeated toluene exposure during adolescence prevents the onset of copulatory behaviour, although this effect is transitory.
We analysed the effects of single and repeated toluene inhalation (6,000 ppm) on sexual behaviour of adolescent male rats. Acute toluene exposure impaired copulatory performance, diminished sexual incentive motivation and delayed noncontact erection in sexually experienced rats. Repeated toluene exposure during adolescence inhibited the onset of copulatory behaviours in sexually naïve rats. Data highlight the behavioural disruption produced by drug misuse during a critical developmental period.
Sexual aggression in mammals Cassini, Marcelo H.
Mammal review,
April 2021, 2021-04-00, 20210401, Letnik:
51, Številka:
2
Journal Article
Recenzirano
In non‐human mammals, sexual conflict should be particularly intense because males rarely provide parental care. An expected consequence of sexual conflict is male aggression towards mates. ...Considering how complex measurements and interpretations of behaviours such as sexual aggression and sexual coercion are, I preferred to define operationally, as ‘sexual disturbance’, any male behaviour towards females during the pericopulatory period that can be costly for females.
The objectives in this review were as follows: 1) to estimate how widespread sexual disturbance is among mammals, 2) to analyse the types of female response to sexual disturbance, and 3) to characterise the costs of sexual disturbance to females. I conducted a systematic review by searching the literature in the Web of Knowledge database using the search tools available for 19 main journals, and I conducted a qualitative review via a taxon‐by‐taxon analysis.
Sexual disturbance was frequent in four of the 32 mammalian orders: Primates, Artiodactyla, Carnivora, and Cetacea, which all include highly polygynous taxa. The most common expression of sexual conflict around copulation is seen in behaviours associated with female retention attempts that cause minor harm. Research suggests that the most common response of females to sexual disturbance comprises female grouping around a dominant male.
RESUMEN EN ESPAÑOL
En mamíferos no‐humanos, el conflicto sexual puede ser particularmente intenso debido a que los machos raramente proveen cuidado parental. Una consecuencia esperada del conflicto sexual es la agresión sexual hacia las parejas reproductivas. Considerando que las medidas e interpretaciones de conductas tales como la agresión sexual y la coerción social pueden ser muy complejas, preferí definir operacionalmente como 'perturbación sexual' a cualquier comportamiento de los machos hacia hembras durante el período peri‐copulatorio que podría ser costoso para las hembras.
Los objetivos de esta revisión fueron: 1) estimar cuan difundida está la perturbación sexual entre los mamíferos, 2) analizar los tipos de respuestas de las hembras a la perturbación sexual, y 3) caracterizar los costos de la perturbación sexual para las hembras. Realicé una revisión sistemática buscando publicaciones en internet, usando las herramientas de búsqueda disponibles en 19 revistas científicas relevantes, y conduje una revisión cualitativa a través de un análisis taxón por taxon.
La perturbación sexual fue frecuente en cuatro de 32 órdenes de mamíferos: Primates, Artiodactyla, Carnivora y Cetacea, los cuales en todos los casos incluyen taxones altamente poligínicos. La expresión más común del conflicto sexual alrededor de la cópula son conductas asociadas a intentos de retención de las hembras que producen un daño menor.
The most accepted current evolutionary theory suggests that there is an inherent conflict in sexual relationships as a result of inequalities of interests. An expected consequence of this conflict is sexual aggression. I reviewed the literature on mating behaviour in order to estimate how widespread male sexual aggression is among mammals and to analyse female responses and costs. Among the more than 5000 species of mammals, there are reports of sexual violence, particularly in highly polygynous species. However, the most common expression of sexual conflict around copulation is seen in behaviours associated with female retention attempts that cause minor harm. Research suggests that the most common response of females to sexual disturbance comprises female grouping around a dominant male. Photograph: A young adult male sea lion Otaria flavescens trying to retain a female, Les Éclaireurs Islands, Beagle Channel, by M. H. Cassini.
We hypothesized that male meadow voles adjust their odour preferences and sexual behaviours in response to the presence and number of male conspecifics they perceive to have visited a sexually ...receptive female conspecific. Male voles only preferred the odour of the female previously associated with 3 or 5 males to that of the unfamiliar female. Male voles also had a shorter latency to mate and a shorter mating duration when they were paired with the female that was previously associated with the bedding of 3 or 5 males compared to males paired with an unfamiliar female. Mating and reproductive success, however, were similar for males paired with either female. Thus, male voles use public information provided by scent marks of male conspecifics and adjust their responses in favour of a female that they perceive to been visited by several males, although she may represent a high risk of sperm competition.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Females of many species mate with multiple males (polyandry), resulting in male–male competition extending to post‐copulation (sperm competition). Males adapt to such post‐copulatory sexual selection ...by altering features of their ejaculate that increase its competitiveness and/or by decreasing the risk of sperm competition through female manipulation or interference with rival male behaviour. At ejaculation, males of many species deposit copulatory plugs, which are commonly interpreted as a male adaptation to post‐copulatory competition and are thought to reduce or delay female remating. Here, we used a vertebrate model species, the house mouse, to study the consequences of copulatory plugs for post‐copulatory competition. We experimentally manipulated plugs after a female's first mating and investigated the consequences for rival male behaviour and paternity outcome. We found that even intact copulatory plugs were ineffective at preventing female remating, but that plugs influenced the rival male copulatory behaviour. Rivals facing intact copulatory plugs performed more but shorter copulations and ejaculated later than when the plug had been fully or partially removed. This suggests that the copulatory plug represents a considerable physical barrier to rival males. The paternity share of first males increased with a longer delay between the first and second males' ejaculations, indicative of fitness consequences of copulatory plugs. However, when males provided little copulatory stimulation, the incidence of pregnancy failure increased, representing a potential benefit of intense and repeated copulation besides plug removal. We discuss the potential mechanisms of how plugs influence sperm competition outcome and consequences for male copulatory behaviour.
Many aspects of primate reproductive anatomy and physiology have been influenced by copulatory and postcopulatory sexual selection, especially so in taxa where multiple-partner matings by females ...result in the sperm of rival males competing for access to a given set of ova (sperm competition). However, the female reproductive system also exerts profound effects upon sperm survival, storage and transport, raising the possibility that female traits influence male reproductive success (via cryptic female choice). Current knowledge of sperm competition and cryptic choice in primates and other mammals is reviewed here. The relevance of these comparative studies to our understanding of human reproduction and evolution is discussed.
With female multiple mating (polyandry), male-male competition extends to after copulation (sperm competition). Males respond to this selective pressure through physiological, morphological and ...behavioural adaptations. Sperm competitiveness is commonly decreased in heterozygote carriers of male meiotic drivers, selfish genetic elements that manipulate the production of gametes in males. This might give carriers an evolutionary incentive to reduce the risk of sperm competition. Here, we explore this possibility in house mice. Natural populations frequently harbour a well-characterised male driver (t haplotype), which is transmitted to 90 % of heterozygous (+/t) males' offspring. Previous research demonstrated strong detrimental effects on sperm competitiveness, and suggested that +/t males are particularly disadvantaged against wild type males when first-to-mate. Low paternity success in the first-to-mate role is expected to favour male adaptations that decrease the risk of sperm competition by preventing female remating. Genotype-specific paternity patterns (sperm precedence) could lead to genetically determined alternative reproductive tactics that can spread through gene level selection. Here, we seek confirmation that +/t males are generally disadvantaged when first-to-mate and address whether males of different genotypes differ in reproductive tactics (copulatory and morphological) to maximise individual or driver fitness. Finally, we attempt to explain the mechanistic basis for alternative sperm precedence patterns in this species.
We confirmed that +/t males are weak sperm competitors when first to mate. When two +/t males competed, the second-to-mate was more successful, which contrasts with first male sperm precedence when wild type males competed. However, we found no differences between male genotypes in reproductive behaviour or morphology that were consistent with alternative reproductive tactics. Sperm of +/+ and +/t males differed with respect to in vitro sperm features. Premature hypermotility in +/t males' sperm can potentially explain why +/t males are very weak sperm competitors when first-to-mate.
Our results demonstrate that meiotic drivers can have strong effects on sperm precedence patterns, and may provide a heritable basis for alternative reproductive tactics motivated by reduced sperm competitiveness. We discuss how experimental and evolutionary constraints may help explain why male genotypes did not show the predicted differences.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Outbred Roman high- (RHA) and low-avoidance (RLA) rats, originally selected for rapid vs. poor acquisition of active avoidance in a shuttle box, show differential copulatory patterns when exposed to ...a receptive female. Indeed, in the first copulation test male RHA rats show more mounts, intromissions and ejaculations than RLA rats. Such differences do not disappear in subsequent copulation tests, with sexually experienced RHA rats always showing higher levels of sexual motivation and performance than their RLA counterparts. This study shows that the different copulatory patterns of sexually experienced RHA and RLA rats are differentially facilitated by apomorphine, a mixed D1/D2-like dopamine receptor agonist, and impaired by haloperidol, a D2-like dopamine receptor antagonist, given at doses which facilitate and impair, respectively, copulatory behaviour in Sprague Dawley rats used as an external reference strain. Accordingly, apomorphine-induced facilitation and haloperidol-induced impairment of copulatory behaviour were more robust in RLA than RHA rats, as indicated by their effects on several copulatory parameters including mount, intromission and ejaculation latencies, mount, intromission and ejaculation frequencies, post ejaculatory interval, inter-intromission interval and copulatory efficacy. Pretreatment with haloperidol also reduced the facilitatory effect of apomorphine more effectively in RLA than RHA rats. These results suggest that the different copulatory patterns of RHA and RLA rats are mainly due to a lower dopaminergic tone at level of the mesolimbic and incerto-hypothalamic dopaminergic systems of RLA vs. RHA rats, which play a key role in sexual behaviour.
•Roman High (RHA) and Low (RLA) avoidance rats show different copulatory patterns.•RHA rats show higher sexual motivation and better copulatory performance than RLA rats.•The D1/D2 agonist apomorphine improves copulation in RLA but not in RHA rats.•The D2-antagonist haloperidol further impairs copulation in RLA but not in RHA rats.•Central dopamine is involved in the different copulatory patterns of the Roman rat lines.
Abstract Roman high- (RHA) and low-avoidance (RLA) rats, selectively bred for, respectively, rapid vs. extremely poor acquisition of avoidant behaviour in the shuttle-box, display different coping ...strategies when exposed to aversive environmental conditions: RLA rats are reactive copers and show hyperemotional behaviour characterized by hypomotility and freezing, while RHA rats show a proactive coping behaviour aimed at gaining control over the stressor. RHA rats also display a robust sensation/novelty seeking profile, high baseline levels of impulsivity, and marked preference for, and intake of, natural and drug rewards. This study shows that the Roman lines also differ in sexual behaviour, a main source of natural reward. Thus, male RHA rats engaged in copulatory activity with a receptive female showing more mounts, intromissions and ejaculations in the first copulation test as compared with their RLA counterparts and Sprague Dawley rats used as an external reference strain. Such differences decreased only partially in subsequent copulation tests, with RHA rats always showing higher levels of sexual motivation and performance than RLA rats. Accordingly, analysis of copulatory parameters of five copulation tests performed at 3-day intervals confirmed that the Roman lines display different patterns of copulatory activity that persist after stabilization of copulatory behaviour by sexual experience. Finally, the weight of the testes, epididymides and seminal vesicles increased to a similar extent in both Roman lines after sexual activity. These results are discussed in terms of the relative contribution of differences in brain neurotransmission (mainly dopamine) and neuroendocrine function to the different patterns of copulatory behaviour of the Roman lines.
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