Cynopterus Sphinx Research Articles

Males and females gain differentially from sociality in a promiscuous fruit bat Cynopterus sphinx.

Sociality emerges when the benefits of group living outweigh its costs. While both males and females are capable of strong social ties, the evolutionary drivers for sociality and the benefits accrued maybe different for each sex. In this study, we investigate the differential reproductive success benefits of group membership that males and females might obtain in the promiscuous fruit bat Cynopterus sphinx. Individuals of this species live in flexible social groups called colonies. These colonies are labile and there is high turnover of individuals. However, colony males sire more offspring within the colony suggesting that being part of a colony may result in reproductive benefits for males. This also raises the possibility that long-term loyalty towards the colony may confer additional advantage in terms of higher reproductive success. We used ten seasons of genetic parentage data to estimate reproductive success and relatedness of individuals in the colony. We used recapture data to identify long and short-term residents in the colony as well as to obtain rates of recapture for males and females. Our results reveal that males have a significantly higher chance of becoming long-term residents (than females), and these long-term resident males gain twice the reproductive success compared to short-term resident males. We also observed that long-term resident females are related to each other and also achieve higher reproductive success than short-term resident females. In contrast, long-term resident males do not differ from short-term resident males in their levels of relatedness. Our results re-iterate the benefits of sociality even in species that are promiscuous and socially labile and possible benefits of maintaining a colony.

Timing of Cave Emergence and Return in the Dawn Bat (Eonycteris spelaea, Chiroptera: Pteropodidae) in Southern Thailand

The time of emergence of bats from their roosts at dusk and their return was originally described as a circadian rhythm entrained by the time of sunset and sunrise (Erkert 1978). Later, various environmental factors such as ambient light conditions, weather (Frick et al. 2012) and moonlight (Elangovan and Marimuthu 2001; Thies et al. 2006) were considered to influence bat activity. Bats emerging before dark or during bright moonlight in­ creases their risk of predation by raptorial birds and they avoid such situations (Welbergen 2006). However insecti­ vorous bats often risk predation to increase foraging opportunities when their prey is available in abundance at dusk (Jones and Rydell 1994; Rydell et al. 1996; Duverge et al. 2000). Besides environmental factors, foraging efforts differ between male and female mammals according to the energetic requirements of reproduction (Bronson 1985). Breeding females allocate more time and energy to for­ aging to meet the energy demands of growing pups (McCracken and Wilkinson 2000; Racey and Entwistle 2000; Barclay and Harder 2003). In contrast, reproduc­ tive males spend time and energy in defending females or resources useful to them in order to achieve mating suc­ cess with multiple females (Clutton­Brock 1989). In fruit bats, roost emergence and return times of adult males often differ compared with other reproductive categories, especially during the breeding period. For example, adult males of Old World tent­making (e.g., Cynopterus sphinx) and cavity roosting fruit bats (e.g., Balionycteris maculata) spend less time away from the roost for­ aging and more time at the roost (Balasingh et al. 1995; Marimuthu et al. 1998; Hodgkison et al. 2003). Adult male Rousettus aegyptiacus and Pteropus tonganus emerge after adult females (Korine et al. 1994; Banack and Grant 2003). Similar patterns were found in neotropical fruit bats such as Artibeus jamaicensis (Morrison and Morrison 1981) and A. lituratus (Munoz­Romo et al. 2008). In Southeast Asia, Eonycteris spelaea roosts in caves and travels over tens of kilometres to access food sources (Start 1974). It is the principal pollinator of economi­ cally important crops like durian (Durio zibethinus), a leguminous canopy tree Parkia spp. and the Indian trumpet flower (Oroxylum indicum) in managed agri­ cultural habitats in southern Thailand (Bumrungsri et al. 2008, 2009; Srithongchuay et al. 2008). Eonycteris spelaea reproduces year round (Beck and Lim 1973; Bhat et al. 1980; Heideman and Utzurrum 2003). In a previous study, a capture survey at a cave entrance suggested a high proportion of mature males return during the early hours of the night (Bumrungsri et al. 2013). We investigated the emergence and return time of the dawn nectar bat, E. spelaea, using radio­telemetry to record the time of cave emergence and return by E. spelaea of known sex and reproductive status. We hy­ pothesized differential foraging durations between adult male E. spelaea and other reproductive categories.

Activity-dependent expression of miR-132 regulates immediate-early gene induction during olfactory learning in the greater short-nosed fruit bat, Cynopterus sphinx

The activity-dependent expression of immediate-early genes (IEGs) and microRNA (miR)-132 has been implicated in synaptic plasticity and the formation of long-term memory (LTM). In the present study, we show that olfactory training induces the expression of IEGs (EGR-1, C-fos, C-jun) and miR-132 at similar time scale in olfactory bulb (OB) of Cynopterus sphinx. We examined the role of miR-132 in the OB using antisense oligodeoxynucleotide (AS-ODN) and demonstrated that a local infusion of AS-ODN in the OB 2h prior to training impaired olfactory memory formation in C. sphinx. However, the infusion of AS-ODN post-training did not cause a deficit in memory formation. Furthermore, the inhibition of miR-132 reduced the olfactory training-induced expression of IEGs and post synaptic density protein-95 (PSD-95) in the OB. Additionally, we show that miR-132 regulates the activation of calcium/calmodulin-dependent protein kinase-II (CaMKII) and cAMP response element binding protein (CREB), possibly through miR-148a. These data suggest that olfactory training induces the expression of miR-132 and IEGs, which in turn activates post-synaptic proteins that regulate olfactory memory formation.

Molecular detection and genotypic characterization of Toxoplasma gondii infection in bats in four provinces of China.

BackgroundToxoplasma gondii is an intracellular protozoan parasite that infects a wide variety of warm-blooded hosts, including humans. Limited information about T. gondii infection in bats is available in China. The objective of the present study was to determine prevalence and genetic characterization of T. gondii infection in bats in Jilin, Liaoning, Jiangxi and Guangdong provinces, China.MethodsDuring May 2005 to August 2013, bats were sampled from Jilin, Liaoning, Jiangxi, and Guangdong provinces, China, and liver tissues were collected for the detection of T. gondii by a nested PCR targeting the B1 gene. The positive samples were genotyped at 11 genetic markers (SAG1, 5′-and 3′-SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and Apico) using multilocus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).ResultsA total of 626 bats representing 10 species were examined for T. gondii infection, 38 (6.1%) were tested positive with by PCR, 8 positive DNA samples were completely genotyped, of which 3 samples (2 from Cynopterus sphinx, and 1 from Murina leucogaster) represented ToxoDB#10, and 5 samples (2 from Murina leucogaster, 2 from Myotis chinensis, and 1 from Rhinolophus ferrumequinum) belonged to ToxoDB#9 (http://toxodb.org/toxo/).ConclusionsThe present study revealed an overall T. gondii prevalence of 6.1% in bats from Jilin, Liaoning, Jiangxi and Guangdong provinces in China, and reported two T. gondii genotypes (ToxoDB#9 and #10) having a wide geographical distribution in China. These results provide new genetic information about T. gondii infection in bats, and have implications for better understanding of the genetic diversity of T. gondii in China and elsewhere.

Molecular Reproduction & Development Volume 81, Issue 12, December 2014 cover image

Molecular Reproduction and DevelopmentVolume 81, Issue 12 p. C1-C1 On the CoverFree Access Molecular Reproduction & Development Volume 81, Issue 12, December 2014 cover image First published: 29 December 2014 https://doi.org/10.1002/mrd.22255AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract The fruit bat Cynopterus sphinx breeds twice in a year in quick succession, once in winter and again in summer, carrying a single fetus each time. An unusual feature of the animal is that, as compared to the pregnancy of summer, the winter pregnancy is elongated due to delayed growth of the embryo at the early gastrula stage. Anuradha and Krishna (this issue) demonstrate the role of adiponectin in the reactivation of embryonic development following this winter delay. Photography credit to Arup Acharjee. Volume81, Issue12December 2014Pages C1-C1 RelatedInformation

Role of adiponectin in delayed embryonic development of the short-nosed fruit bat, Cynopterus sphinx.

The aim of this study was to evaluate the role of adiponectin in the delayed embryonic development of Cynopterus sphinx. Adiponectin receptor (ADIPOR1) abundance was first observed to be lower during the delayed versus non-delayed periods of utero-embryonic unit development. The effects of adiponectin treatment on embryonic development were then evaluated during the period of delayed development. Exogenous treatment increased the in vivo rate of embryonic development, as indicated by an increase in weight, ADIPOR1 levels in the utero-embryonic unit, and histological changes in embryonic development. Treatment with adiponectin during embryonic diapause showed a significant increase in circulating progesterone and estradiol concentrations, and in production of their receptors in the utero-embryonic unit. The adiponectin-induced increase in estradiol synthesis was correlated with increased cell survival (BCL2 protein levels) and cell proliferation (PCNA protein levels) in the utero-embryonic unit, suggesting an indirect effect of adiponectin via estradiol synthesis by the ovary. An in vitro study further confirmed the in vivo findings that adiponectin treatment increases PCNA levels together with increased uptake of glucose by increasing the abundance of glucose transporter 8 (GLUT8) in the utero-embryonic unit. The in vitro study also revealed that adiponectin, together with estradiol but not alone, significantly increased ADIPOR1 protein levels. Thus, adiponectin works in concert with estradiol to increase glucose transport to the utero-embryonic unit and promote cell proliferation, which together accelerate embryonic development.

Modulation of ovarian steroidogenesis by adiponectin during delayed embryonic development of Cynopterus sphinx

The aim of present study was to evaluate role of adiponectin in ovarian steroidogenesis during delayed embryonic development of Cynopterus sphinx. This study showed significantly low circulating adiponectin level and a decline in expression of adiponectin receptor 1 (AdipoR1) in the ovary during the period of delayed embryonic development as compared with the normal development. The adiponectin treatment in vivo during the period of delayed development caused significantly increased in circulating progesterone and estradiol levels together with increased expression of AdipoR1 in the ovary. The in vitro study confirmed the stimulatory effect of adiponectin on progesterone synthesis. Both in vivo and in vitro studies showed that the effects of adiponectin on ovarian steroidogenesis were mediated through increased expression of luteinizing hormone-receptor, steroidogenic acute regulatory protein and 3β-hydroxyl steroid dehydrogenase enzyme. The adiponectin treatment may also promote progesterone synthesis by modulating ovarian angiogenesis, cell survival and rate of apoptosis.

Prevalence and genetic characterization of Toxoplasma gondii infection in bats in southern China

Toxoplasma gondii can infect a wide variety of warm-blooded animals, including bats. Limited information on T. gondii infection in bats is available in China. The objective of the present study was to determine prevalence and genetic diversity of T. gondii infection in bats in southern China. A total of 608 bats representing 12 species, including 120 Aselliscus stoliczkanus, 59 Myotis chinensis, 11 Miniopterus schreibersii, 53 Rhinolophus affinis, 32 Rhinolophus pusillus, 81 Hipposideros armiger, 28 Hipposideros fulvus, 32 Cynopterus brachyotis, 14 Cynopterus sphinx, 45 Eonycteris spelaea, 109 Hipposideros larvatus, and 24 Taphozous melanopogon, were collected from Yunnan and Guangxi provinces, southern China. They were examined for the presence of T. gondii DNA by amplification of the B1 gene using a nested PCR, and the positive samples were genotyped at 11 genetic loci (SAG1, 5′- and 3′-SAG2, alternative SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) using multilocus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Fifty-nine (9.7%) of these bats were detected positive by PCR but only five of these positive DNA samples were completely typed at all loci; of which 4 samples, 2 from A. stoliczkanus, and 2 from H. larvatus, belonged to ToxoDB Genotype #10, and the other one from H. larvatus was identified as ToxoDB Genotype #9 (http://toxodb.org/toxo/). To our knowledge, this is the first report of molecular detection and genetic characterization of T. gondii infection in bats in China. The results show that these bats are potential reservoirs for T. gondii transmission, which may pose a threat to human health.

Complete mitochondrial genome of Cynopterus sphinx (Pteropodidae: Cynopterus)

We have characterized the complete mitochondrial genome of Cynopterus sphinx (Pteropodidae: Cynopterus) and described its organization in this study. The total length of C. sphinx complete mitochondrial genome was 16,895 bp with the base composition of 32.54% A, 14.05% G, 25.82% T and 27.59% C. The complete mitochondrial genome included 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes (12S rRNA and 16S rRNA) and 1 control region (D-loop). The control region was 1435 bp long with the sequence CATACG repeat 64 times. Three protein-coding genes (ND1, COI and ND4) were ended with incomplete stop codon TA or T.

Scanning electron microscopy study of guard hair of three Indian pteropodid bats

A comparative study on the hair microstructure of pteropodid bats Pteropus giganteus , Rousettus leschenaulti , and Cynopterus sphinx was performed using scanning electron microscope. Hair samples were taken from the dorsal, ventral, and neck regions. Among the three pteropodids examined, an imbricate and tightly appressed hair type was observed in P. giganteus , while a coronal type of cuticle with margins diverging from the shaft was observed in R. leschenaulti and C. sphinx . The coronal cuticles of R. leschenaulti and C. sphinx had relatively thinner scale widths than the imbricate cuticles of P. giganteus . There was a significant difference in hair length, scale lengths and scale widths, and scale indices among the three species of fruit bats. However, there was no significant difference in hair length and scale index of male and female R. leschenaulti as well as in hair length and scale indices of male and female C. sphinx . The presence of bell-shaped coronal cuticle and wide angular scale margin in R. leschenaulti and C. sphinx reveal their role as active pollinators. The hair patterns, hair length, scale length and width confirm the presence of species-specific characteristics of pteropodid bats and can be used for species identification.

Molecular detection and genotypic characterization of Toxoplasma gondii infection in bats in four provinces of China

BackgroundToxoplasma gondii is an intracellular protozoan parasite that infects a wide variety of warm-blooded hosts, including humans. Limited information about T. gondii infection in bats is available in China. The objective of the present study was to determine prevalence and genetic characterization of T. gondii infection in bats in Jilin, Liaoning, Jiangxi and Guangdong provinces, China.MethodsDuring May 2005 to August 2013, bats were sampled from Jilin, Liaoning, Jiangxi, and Guangdong provinces, China, and liver tissues were collected for the detection of T. gondii by a nested PCR targeting the B1 gene. The positive samples were genotyped at 11 genetic markers (SAG1, 5′-and 3′-SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and Apico) using multilocus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).ResultsA total of 626 bats representing 10 species were examined for T. gondii infection, 38 (6.1%) were tested positive with by PCR, 8 positive DNA samples were completely genotyped, of which 3 samples (2 from Cynopterus sphinx, and 1 from Murina leucogaster) represented ToxoDB#10, and 5 samples (2 from Murina leucogaster, 2 from Myotis chinensis, and 1 from Rhinolophus ferrumequinum) belonged to ToxoDB#9 (http://toxodb.org/toxo/).ConclusionsThe present study revealed an overall T. gondii prevalence of 6.1% in bats from Jilin, Liaoning, Jiangxi and Guangdong provinces in China, and reported two T. gondii genotypes (ToxoDB#9 and #10) having a wide geographical distribution in China. These results provide new genetic information about T. gondii infection in bats, and have implications for better understanding of the genetic diversity of T. gondii in China and elsewhere.

Role of olfaction in the foraging behavior and trial-and-error learning in short-nosed fruit bat, Cynopterus sphinx

We observed the foraging behavior of short-nosed fruit bats, Cynopterus sphinx, in captivity. The role of olfaction in their foraging behavior was examined using real fruit, mimetic fruit, and mimetic fruit soaked in the juice of real fruit. The results showed that C. sphinx visited the real fruit more often than the mimetic fruit, but they had no preference between real fruit and treated mimetic fruit. Our experiment indicates that this bat has the ability to find and identify fruit by olfaction. We also tested for behavior of trial-and-error learning. Our observations revealed that the bats could form a sensory memory of the olfactory cue (cedar wood oil) after five days of training because they responded to the olfactory cues. Our results provide the evidence that C. sphinx can establish the connection between the fruit and a non-natural odor through learning and memory with the assistance of olfaction, and can thus recognize a variety of odors by trial-and-error learning. This behavioral flexibility based on olfactory cues will be beneficial for the short-nosed fruit bat in foraging.

Distress calls of the greater short-nosed fruit bat Cynopterus sphinx activate hypothalamic-pituitary-adrenal (HPA) axis in conspecifics

In a stressful situation, greater short-nosed fruit bats (Cynopterus sphinx) emit audible vocalization either to warn or to inform conspecifics. We examined the effect of distress calls on bats emitting the call as well as the bats receiving the distress signal through analysis of the hypothalamic-pituitary-adrenal axis and catacholaminargic systems. We measured the levels of neurotransmitters [serotonin (5-HT), dopamine (DA), norepinephrine (NE)] and stress hormones [(adrenocorticotropic hormone (ACTH) and corticosterone (CORT)]. Our results showed that distress call emission elevated the level of ACTH and CORT, as well as 5-HT, DA and NE in the amygdala, for both the call emitting bat and the responding bat. Subsequently, we observed increased activity of glucocorticoid receptor and its steroid receptor co-activator (SRC-1). An expression of SRC-1 was up-regulated in the distress call emitter only, whereas it was at a similar level in both the call responder and silent bats. These findings suggest that bats emitting distress calls and also bats responding to such calls have similar neurotransmitter expression patterns, and may react similarly in response to stress.

Cunnilingus Apparently Increases Duration of Copulation in the Indian Flying Fox, Pteropus giganteus

We observed a total of 57 incidences of copulation in a colony of the Indian flying fox, Pteropus giganteus, over 13 months under natural conditions. The colony consisted of about 420 individuals, roosting in a Ficus religiosa tree. Copulations occurred between 07.00 h and 09.30 h from July to January, with more occurring in October and November. Initially males groomed their penis before approaching a nearby female. Females typically moved away and males followed. When the female stopped moving, the male started licking her vagina (cunnilingus). Typically each bout of cunnilingus lasted for about 50 s. In 57 out of 69 observations, the male mounted the female and copulated. The duration of copulation varied from 10 to 20 sec. After completion of copulation, the male continued cunnilingus for 94 to 188 sec. The duration of pre-copulatory cunnilingus and copulation was positively correlated whereas, the duration of pre- and post-copulatory cunnilingus was negatively correlated. Apart from humans, oral sex as foreplay prior to copulation is uncommon in mammals. Another pteropodid bat, Cynopterus sphinx exhibits fellatio with females licking the penis of males during copulation. It appears that bats, especially pteropodids perform oral sex, either cunnilingus or fellatio, possibly for achieving longer copulation.

Serological Evidence ofToxoplasma gondiiInfection in Five Species of Bats in China

Toxoplasma gondii is an obligate intracellular protozoan parasite that can infect almost all warm-blooded animals and humans with a worldwide distribution. Bats are reservoirs for an increasing number of emerging zoonotic viruses, such as henipaviruses and severe acute respiratory syndrome coronavirus (SARS-CoV). However, little is known of T. gondii infection in bats. The objective of the present study was to determine the seroprevalence of T. gondii infection in bats in China. A total of 217 serum samples from 5 species of bats were collected between April, 2010, and August, 2011, from 4 provinces in China. Antibodies to T. gondii were determined using the modified agglutination test (MAT, 1:25 or higher). Antibodies to T. gondii were found in 26.5% (18/68) Megaderma lyra, 13.6% (12/88) Rousettus leschenaulti, 13.6% (3/22) Cynopterus sphinx, 20% (4/20) Vespertilio superaus, and 15.8% (3/19) Pipistrellus javanicus. Antibody titers ranged from 1:25 to 1:400, with titers of 1:200 detected in 4 of the 5 bat species. The present study suggests the likely occurrence of T. gondii infection in bats in China, and these bats are new putative hosts for T. gondii, which may pose a threat to human health.

Comparative inner ear transcriptome analysis between the Rickett’s big-footed bats (Myotis ricketti) and the greater short-nosed fruit bats (Cynopterus sphinx)

BackgroundBats have aroused great interests of researchers for the sake of their advanced echolocation system. However, this highly specialized trait is not characteristic of Old World fruit bats.ResultsTo comprehensively explore the underlying molecular basis between echolocating and non-echolocating bats, we employed a sequence-based approach to compare the inner ear expression difference between the Rickett’s big-footed bat (Myotis ricketti, echolocating bat) and the Greater short-nosed fruit bat (Cynopterus sphinx, non-echolocating bat). De novo sequence assemblies were developed for both species. The results showed that the biological implications of up-regulated genes in M. ricketti were significantly over-represented in biological process categories such as ‘cochlea morphogenesis’, ‘inner ear morphogenesis’ and ‘sensory perception of sound’, which are consistent with the inner ear morphological and physiological differentiation between the two bat species. Moreover, the expression of TMC1 gene confirmed its important function in echolocating bats.ConclusionOur work presents the first transcriptome comparison between echolocating and non-echolocating bats, and provides information about the genetic basis of their distinct hearing traits.

Detection of Nipah Virus RNA in Fruit Bat (Pteropus giganteus) from India

The study deals with the survey of different bat populations (Pteropus giganteus, Cynopterus sphinx, and Megaderma lyra) in India for highly pathogenic Nipah virus (NiV), Reston Ebola virus, and Marburg virus. Bats (n = 140) from two states in India (Maharashtra and West Bengal) were tested for IgG (serum samples) against these viruses and for virus RNAs. Only NiV RNA was detected in a liver homogenate of P. giganteus captured in Myanaguri, West Bengal. Partial sequence analysis of nucleocapsid, glycoprotein, fusion, and phosphoprotein genes showed similarity with the NiV sequences from earlier outbreaks in India. A serum sample of this bat was also positive by enzyme-linked immunosorbent assay for NiV-specific IgG. This is the first report on confirmation of Nipah viral RNA in Pteropus bat from India and suggests the possible role of this species in transmission of NiV in India.

Egr-1 antisense oligodeoxynucleotide administration into the olfactory bulb impairs olfactory learning in the greater short-nosed fruit bat Cynopterus sphinx

Postsynaptic densities (PSDs) contain proteins that regulate synaptic transmission. We examined two important examples of these, calcium/calmodulin-dependent protein kinase II (CaMKII) and PSD-95, in regard to the functional role of early growth response gene-1 (egr-1) in regulation of olfactory learning in the greater short-nosed fruit bat Cynopterus sphinx (family Pteropodidae). To test whether activation of egr-1 in the olfactory bulb (OB) is required for olfactory memory of these bats, bilaterally canulated individuals were infused with antisense (AS) or non-sense (NS)-oligodeoxynucleotides (ODN) of egr-1, or with phosphate buffer saline (PBS), 2h before the olfactory training. Our results showed that behavioral training significantly up-regulates immediate early gene (IEG) EGR-1 and key synaptic proteins Synaptotagmin-1(SYT-1), CaMKII and PSD-95, and phosphorylation of CaMKII in the OB at the protein level per se. Subsequently, we observed that egr-1 antisense-ODN infusion in the OB impaired olfactory memory and down regulates the expression of CaMKII and PSD-95, and the phosphorylation of CaMKII but not SYT-1. In contrast, NS-ODN or PBS had no effect on the expression of the PSDs CaMKII or PSD-95, or on the phosphorylation of CaMKII. When the egr-1 NS-ODN was infused in the OB after training for the novel odor there was no effect on olfactory memory. These findings suggest that egr-1 control the activation of CaMKII and PSD-95 during the process of olfactory memory formation.

Promiscuous mating in the harem‐roosting fruit bat,Cynopterus sphinx

Observations on mating behaviours and strategies guide our understanding of mating systems and variance in reproductive success. However, the presence of cryptic strategies often results in situations where social mating system is not reflective of genetic mating system. We present such a study of the genetic mating system of a harem-forming bat Cynopterus sphinx where harems may not be true indicators of male reproductive success. This temporal study using data from six seasons on paternity reveals that social harem assemblages do not play a role in the mating system, and variance in male reproductive success is lower than expected assuming polygynous mating. Further, simulations reveal that the genetic mating system is statistically indistinguishable from promiscuity. Our results are in contrast to an earlier study that demonstrated high variance in male reproductive success. Although an outcome of behavioural mating patterns, standardized variance in male reproductive success (I(m)) affects the opportunity for sexual selection. To gain a better understanding of the evolutionary implications of promiscuity for mammals in general, we compared our estimates of I(m) and total opportunity for sexual selection (I(m) /I(f), where I(f) is standardized variance in female reproductive success) with those of other known promiscuous species. We observed a broad range of I(m) /I(f) values across known promiscuous species, indicating our poor understanding of the evolutionary implications of promiscuous mating.

A Test for Sex-Biased Dispersal inCynopterus sphinx: Inferences from Microsatellite Markers and Mitochondrial DNA

The greater short-nosed fruit bat (Cynopterus sphinx) is a social species, widely distributed in southern Asia. We used microsatellite and mfDNA markers to assess whether this fruit bat has a sex biased dispersal pattern. We also assessed signatures of sex-biased migration using microsatellite data. No significant heterozygosity deficiency (FIS), lower assignment value (mAIc) and variance of assignment (vAIc) were found between females and males, which does not support the hypothesis that dispersal in C. sphinx is sex biased. When microsatellite genotype frequency and mfDNA haplotype distribution patterns were subjected to the AMOVA, we found that genetic partitioning was higher at mfDNA (ΦST) than autosomal markers (FST) in both sexes. There is a higher value for males than females in both the mtDNA and microsatellite data, and both adult males and females also exhibited more variation within than among populations, but without significant results. Our results indicated that C. sphinx displayed various s...