Evidence Of Multiple Paternity Research Articles

First evidence of multiple paternity and hybridisation in Australian sawsharks

Context Knowledge of sawshark reproductive biology is limited to general parameters such as reproductive mode and litter size. The mating system is currently unknown. Aim To test for multiple paternity in the common (Pristiophorus cirratus) and southern (Pristiophorus nudipinnis) sawshark and investigate the occurrence of hybridisation between these two species. Methods Pups from a single litter of each species and an adult P. nudipinnis displaying mismatches in its morphology and mitochondrial DNA were genotyped with nuclear single-nucleotide polymorphisms (SNPs). Multiple paternity was assessed using pairwise relatedness and sibship analysis, and hybridisation was examined using three approaches (principal-component analysis, admixture analysis and clustering with NewHybrids). Key results Multiple paternity was detected in both species, with two males siring the seven-pup litter in P. cirratus and two males siring the two-pup litter in P. nudipinnis. Hybridisation between the two species was also confirmed, with the mismatched adult identified as a first-generation hybrid. Conclusions The mating system of sawsharks involves polyandry, and hybridisation between the two co-occurring Australian species is possible. Implications These results provide new information on sawshark reproductive biology and highlight the need for combined use of mitochondrial and nuclear markers in future genetic studies involving these species.

Research of Mating System in Tupaia belangeri by Microsatellite DNA Markers

Mating system of a population refers to the general behavioral strategies which employed in obtaining mates. In order to investigate the genetic parentage of 151 individuals in Tupaia belangeri from Haikou Forest Farm, 8 microsatellite loci with higher polymorphic characters were used for genetic relationship analysis. The results showed that the number of alleles per polymorphic locus in 151 individuals ranged from 2 to 9. The average observed and expected heterozygosities per locus ranged from 0.2476 to 0.8367 and from 0.2789 to 0.7773, respectively. While the polymorphic information content ranged from 0.2469 to 0.7773. Except the locus (TBC1) deviated from Hardy–Weinberg equilibrium, the others 7 microsatellite loci were employed to research the mating system in T. belangeri, which found that non-strictly monogamous in T. belangeri, but exhibited evidence of multiple paternity. All of the results suggested that characteristics of 8 microsatellite loci provide an excellent tool for the research of mating systems and fine-scaled population structuring of tree shrew, which was the first molecular evidence for mating system in T. belangeri.

Mating frequency and colony genetic structure analyses reveal unexpected polygyny in the Mediterranean acrobat ant Crematogaster scutellaris

Among eusocial Hymenoptera, ants represent an unrivalled example of diversity in number of queens and mating systems. Ant colonies may have one (monogyny) or several queens (polygyny) which can mate once (monoandry) or several times (polyandry). In this study, we analysed the genetic structure and breeding system of the Mediterranean acrobat ant Crematogaster scutellaris. Despite its widespread distribution and pivotal role in regulating arthropod communities, many details of the biology of this species have yet to be fully investigated. According to previous studies based on few observations, C. scutellaris is monogynous and monandrous with a claustral foundation phase. We assessed the mating frequency and the number of queens in 40 colonies using highly polymorphic, species-specific nuclear DNA microsatellite loci. The number of queens in each colony was directly inferred from the relatedness of workers. Moreover, in order to determine the proportion of multiple matings by queens, we performed both parental reconstruction analysis using offspring data and direct analysis of the sperm stored in the queen’s spermathecae. We investigated relatedness between queens and their mated males. The results showed that, although the majority of the colonies were monogynous, polygyny occurred in 10% of the nests. Monoandry was the norm: we found evidence of multiple paternity in just two out of 40 colonies. Finally, no relatedness was found between queens and their mates, indicating that the latter were from different colonies. This work is the first description of the genetic structure of the colonies of C. scutellaris and provides new insight for further investigation on the social organization, behaviour and ecology of Mediterranean acrobat ants.

Evidence for multiple paternity and confirmation of an Indo-Pacific origin of blacktip shark Carcharhinus limbatus occurring in South Africa

The blacktip shark Carcharhinus limbatus is a cosmopolitan species found in warm-temperate, subtropical and tropical waters around the world. The research here aimed to assess whether multiple paternity exists in South African C. limbatus and to confirm phylogeographic patterns previously observed within the species. A minimum and maximum frequency of 50% and 71% multiple paternity, respectively, were observed in 14 litters genotyped with five microsatellite markers. Based on the mitochondrial control region, relatively high nucleotide and haplotype diversity characterised the South African sampling population, and pairwise φST values indicated that it significantly differed from the populations of the Pacific and the western Atlantic oceans. The haplotype network showed that the South African samples were grouped closely with the Australian, Indo-Pacific and West African C. limbatus samples, which is suggestive of an Indo-Pacific origin for this population. This study is the first to report multiple paternity in this species. Furthermore, the results reveal that C. limbatus from South Africa is genetically diverse and phylogeographically distinct from most other C. limbatus populations.

Unique multiple paternity in the endangered big-headed turtle (Platysternon megacephalum) in an ex situ population in South China.

Understanding the mating system and reproductive strategies of an endangered species is critical to the success of captive breeding. The big‐headed turtle (Platysternon megacephalum) is one of the most threatened turtle species in the world. Captive breeding and reintroduction are necessary to re‐establish wild populations of P. megacephalum in some of its historical ranges in China, where the original populations have been extirpated. However, the captive breeding of P. megacephalum is very difficult and this may be due to its mysterious reproductive strategies and special behavior (e.g., aggressive temperament and territoriality). In this study, we achieved successful captive breeding of P. megacephalum by creating a habitat that mimics natural conditions and then investigated its mating system using microsatellite makers. A total of 16 clutches containing 79 eggs of P. megacephalum were collected, and 52 were hatched successfully over two breeding seasons. Of the 15 effective clutches, 6 clutches (40%) exhibited multiple paternity. There was no significant correlation between clutch size and multiple paternity, and no significant difference in hatching success between multiple‐sired and single‐sired clutches. However, there was significant correlation between male body size and the number of offspring, with higher‐ranked males contributing to more clutches. Our results provide the first evidence of multiple paternity and male hierarchy in P. megacephalum. These findings suggest that multiple paternity and male hierarchy should be considered in captive breeding programs for P. megacephalum, and creating a habitat that mimics natural conditions is an effctive way to achieve successful captive breeding and investigate the mating systems of this species.

High levels of multiple paternity in a spermcast mating freshwater mussel.

Multiple paternity is an important characteristic of the genetic mating system and common across a wide range of taxa. Multiple paternity can increase within‐population genotypic diversity, allowing selection to act on a wider spectre of genotypes, and potentially increasing effective population size. While the genetic mating system has been studied in many species with active mating behavior, little is known about multiple paternity in sessile species releasing gametes into the water. In freshwater mussels, males release sperm into the water, while eggs are retained and fertilized inside the female (spermcast mating). Mature parasitic glochidia are released into the water and attach to the gills of fish where they are encapsulated until settling in the bottom substrate. We used 15 microsatellite markers to detect multiple paternity in a wild population of the freshwater pearl mussel (Margaritifera margaritifera). We found multiple paternity in all clutches for which more than two offspring were genotyped, and numbers of sires were extremely high. Thirty‐two sires had contributed to the largest clutch (43 offspring sampled). This study provides the first evidence of multiple paternity in the freshwater pearl mussel, a species that has experienced dramatic declines across Europe. Previous studies on other species of freshwater mussels have detected much lower numbers of sires. Multiple paternity in freshwater pearl mussels may be central for maintaining genetic variability in small and fragmented populations and for their potential to recover after habitat restoration and may also be important in the evolutionary arms race with their fish host with a much shorter generation time.

High levels of polyandry, but limited evidence for multiple paternity, in wild populations of the western rock lobster (Panulirus cygnus).

Polyandry, where multiple mating by females results in the temporal and spatial overlap of ejaculates from two or more males, is taxonomically widespread and occurs in varying frequencies within and among species. In decapods (crabs, lobsters, crayfish, and prawns), rates of polyandry are likely to be variable, but the extent to which patterns of multiple paternity reflect multiple mating, and thus are shaped by postmating processes that bias fertilization toward one or a subset of mated males, is unclear. Here, we use microsatellite markers to examine the frequency of multiple mating (the presence of spermatophores from two or more males) and patterns of paternity in wild populations of western rock lobster (Panulirus cygnus). Our data confirm that >45% of females had attached spermatophores arising from at least two males (i.e., confirming polyandry), but we found very limited evidence for multiple paternity; among 24 clutches sampled in this study, only two arose from fertilizations by two or more males. Single inferred paternal genotypes accounted for all remaining progeny genotypes in each clutch, including several instances when the mother had been shown to mate with two or more males. These findings highlight the need for further work to understand whether polyandry is adaptive and to uncover the mechanisms underlying postmating paternity biases in this system.

A pilot study of multiple paternity in three litters of spiny dogfish (Squalus acanthias) off the South Carolina/Georgia coast

The spiny dogfish (Squalus acanthias) is the target of the largest U.S. shark fishery where stock size is monitored and assessed. Understanding and defining regional populations is essential to conservation efforts. Previous work on spiny dogfish in U.S. waters has concentrated on sampling from New England and the North Carolina/Virginia coast. The migratory habits and reproductive traits of these sharks have been described, but little can be found about the southernmost part of the population, including those occupying the coast of South Carolina and Georgia. This pilot study investigated the reproductive biology of the spiny dogfish in the southernmost region. Three family groups of spiny dogfish were sampled and five microsatellite loci were used to screen for multiple paternity. Both litter size and overall genetic diversity were consistent with values reported in other parts of the range. In addition, no evidence of multiple paternity or parthenogenesis was found in the three family groups. The analysis of additional samples will provide clarity about the southern population and contribute to effective population management.

Multiple paternity in the East Pacific green turtle (Chelonia mydas) from the Pacific coast of Mexico

Multiple paternity is a common phenomenon among marine turtles. This behavior is associated with male density and sperm storage in marine species, but no fitness benefits have been detected in offspring from multiple-sired nests. The green turtle (Chelonia mydas) has been commonly studied around the world. Evidence of multiple paternity in C. mydas ranges from almost zero to 100%. In this study, we investigate multiple paternity in C. mydas using microsatellites to determine the number of males that fertilized clutches during two nesting seasons at a high-density nesting beach in the west coast in Michoacán state, Mexico. The minimum number of eggs per nest needed to detect multiple paternity and the number of males involved in fertilization were also assessed. The results indicated that multiple paternity occurred in up to 75% of the nest samples. In addition, the minimum number of eggs per nest required to detect multiple genotype contributions was 6.66 for two fathers, 12.44 for three fathers, 15.49 for four fathers and 20.24 for five fathers. Females fertilized their eggs using contributions from different males between and within clutches during the nesting season. This behavior led to a multiple paternity pattern, which can be advantageous during different life stages but not necessarily during early life.

First record of colour polymorphism in the Neotropical apple snail Asolene platae: inheritance mechanism and evidence for multiple paternity

ABSTRACTAsolene platae (Ampullariidae) is a dioecious freshwater snail with subaquatic gelatinous egg masses that dwells in the Río de la Plata basin (Argentina). The aim of this study was to describe the inheritance mechanism of the colour variations of the shell and soft parts of this snail, and to study their potential use as a genetic marker. The wild-type phenotype presents dark pigments in the soft parts and in shell bands, whereas the yellow phenotype lacks dark pigments in the soft parts and also most dark bands in the shell, except for a subsutural and a periumbilical band. The data showed that the lack of pigments in A. platae is a recessive homozygotic condition with a simple Mendelian inheritance mechanism. Females of the wild-type phenotype had a higher number of bands than the males. The pigment of the bands of both phenotypes is located in the calcareous matrix of the shell. Using the lack of pigments as a genetic marker we demonstrated the existence of biparental egg masses in A. platae, hitherto known in only one species within the Ampullariidae.

First observation of multiple paternity in loggerhead sea turtles, Caretta caretta, nesting on Dalyan Beach, Turkey

Sea turtles are promiscuous breeders with both males and females mating multiply. Due to this mating system, multiple paternity (MP) occurs in sea turtle clutches, and the frequency of MP varies greatly within and among species. In this study, the paternity of a population of loggerhead sea turtles (Caretta caretta) nesting on Dalyan Beach in Turkey was investigated using two highly polymorphic microsatellite markers (CcP2F11 and CcP7C06). Tissue samples collected from randomly selected hatchlings (a total of 522 hatchlings) from two to three successive clutches (a total of 25 clutches) of 10 nesting females were used for paternity analysis with an average sampling effort of 28.2% of offspring per clutch. Evidence of MP in seven out of 10 females (70%) was found, and it was detected that four out of these seven females mated with at least two males, whereas the remaining three females with at least three males. By analysing the successive clutches of females, it was detected that both the number and genotype of contributing sires was same in all clutches of a given female, possibly due to the lack of successful inter-nesting mating in this population. The high frequency of MP implies the possible high genetic diversity within this population. This study indicates that the density of individuals may be the reason of the high frequency of MP in this relatively small population because mating takes place mainly in a narrow area in Dalyan. The possible mating behaviours of the sea turtles and their population structures were discussed in light of the high frequency of MP within this population reported for the first time.

Mating system and evidence of multiple paternity in the Antarctic brooding sea urchin Abatus agassizii

Broadcasting is the predominant spawning behavior among benthic marine invertebrates, mainly associated with planktotrophic and planktonic lecitotrophic development. Broadcasting allows genetic mixing that should contribute to increase the genetic diversity of a female clutch. Conversely, in brooding species characterized by protected development, oocytes are retained and only sperm is released, which is supposed to limit the number of males that contribute to a female clutch. This spermcasting behavior together with egg retention, unusually frequent among Antarctic marine invertebrates, putatively give brooders low dispersal capacities which may reduce genetic mixing and generate genetic and kinship structure at a small spatial scale. Like many other Antarctic marine benthic invertebrates, the irregular sea urchin Abatus agassizii is a spermcaster that broods its young. In this study, we assessed the genetic diversity among 66 adults using 6 polymorphic microsatellite loci and performed progeny array analyses in order to evaluate the number of mates per female as well as genetic structure at a small spatial scale. A. agassizii exhibited a polyandric system with 2–5 mates per female regardless of population density. Bayesian analyses suggested the absence of genetic structure along our 20-m transect, while relatedness among individuals did not differ from that expected under panmixia. Finally, we conclude that a limited number of males contribute to a female clutch, probably as a consequence of limited sperm dispersal and that movement of adults may be sufficient to avoid kinship structure in the population.

Paternity re-visited in a recovering population of Caribbean leatherback turtles (Dermochelys coriacea)

Sea turtles in general are promiscuous breeders, but previous leatherback paternity studies found only a very low level of multiple paternity or none at all. Three highly polymorphic microsatellite markers (Dc99, Cc117, and Ei8) were used to investigate the paternity of a recovering population of leatherback turtles nesting at Playa Gandoca in Costa Rica, which is part of the Atlantic Costa Rican leatherback nesting population. The aim of this study was to (i) detect multiple paternity, (ii) compare the results to previous studies in the same and different nesting populations, (iii) consider the possibility of sperm storage, (iv) explore the possibility of successful inter-nesting mating taking place, and (v) determine the effect of small population size on mating patterns. Tissue samples from females and hatchlings were collected from one to three consecutive clutches (35 clutches total) of 18 nesting females included in the assay with an average sampling effort of 21.91% of offspring per clutch. Evidence of multiple paternity was found in four out of 18 females (22.22%), which had mated with two to three different males. The results from this study indicate that multiple paternity is more common than previously observed for the Atlantic Costa Rican leatherback nesting population. The analyses of successive clutches from the multiply mated females showed that paternal contribution varies between successive clutches and “new” fathers in consecutive clutches suggest the possibility of successful inter-nesting mating.

Males and females contribute unequally to offspring genetic diversity in the polygynandrous mating system of wild boar.

The maintenance of genetic diversity across generations depends on both the number of reproducing males and females. Variance in reproductive success, multiple paternity and litter size can all affect the relative contributions of male and female parents to genetic variation of progeny. The mating system of the wild boar (Sus scrofa) has been described as polygynous, although evidence of multiple paternity in litters has been found. Using 14 microsatellite markers, we evaluated the contribution of males and females to genetic variation in the next generation in independent wild boar populations from the Iberian Peninsula and Hungary. Genetic contributions of males and females were obtained by distinguishing the paternal and maternal genetic component inherited by the progeny. We found that the paternally inherited genetic component of progeny was more diverse than the maternally inherited component. Simulations showed that this finding might be due to a sampling bias. However, after controlling for the bias by fitting both the genetic diversity in the adult population and the number of reproductive individuals in the models, paternally inherited genotypes remained more diverse than those inherited maternally. Our results suggest new insights into how promiscuous mating systems can help maintain genetic variation.

Evidence for multiple paternity in two species of Orconectes crayfish

Multiple mating is expected to be common in organisms that produce large clutches as a mechanism by which sexual reproduction can enrich genetic variation. For freshwater crayfish, observation of multiple mating suggests the potential for high rates of multiple paternity, but genetic confirmation is largely lacking from natural populations. We studied paternity within wild-caught broods of two crayfish species in the genus Orconectes (Sanborn’s crayfish (Orconectes sanbornii (Faxon, 1884)) and the Allegheny crayfish (Orconectes obscurus (Hagen, 1870))). Although females have been observed mating with multiple males, this is the first genetic confirmation of multiple paternity in broods of these two species. Berried females were collected in the field and maintained in aquaria until their eggs hatched. We amplified and genotyped extracted DNA from maternal and hatchling tissue for several microsatellite loci. For both species, paternity reconstruction (GERUD 2.0) yielded 2–3 sires per brood and no single paternity clutches. We discuss these results from natural populations in light of the body of work on reproductive ecology of decapod crustaceans and in the context of changes in life history following the transition from marine to freshwater habitats.

Evidence for multiple paternity in the school shark Galeorhinus galeus found in New Zealand waters.

This study assessed the levels of relatedness of Galeorhinus galeus of progeny arrays using six microsatellite DNA markers. A parentage analysis from five families (mother and litter) from the North Island of New Zealand suggested the occurrence of genetic polyandry in G. galeus with two of the five litters showing multiple sires involved in the progeny arrays. This finding may be consistent with the reproductive characteristics of G. galeus, in which females can potentially store sperm for long periods of time after the mating season.

Twenty new microsatellite loci for population structure and parentage studies of Parnassius apollo nevadensis (Lepidoptera; Papilionidae)

We characterized 20 new microsatellite loci isolated from Parnassius apollo nevadensis. The 20 loci displayed 2–12 alleles and expected heterozygosities varied from 0.22 to 0.89; the markers were amplified in nine multiplex reactions. The combined non-exclusion probabilities of this set are 0.001084 and 0.000005 for the first and second parents, respectively. This set of markers will thus enable other studies on reproductive strategies and population genetics in this endangered and previously understudied species. We show, for the first time, evidence of multiple paternity and that females may successfully copulate with more than one male despite the presence of mating plugs. Future studies on this mating behavior and population genetics of the species using the 20 loci here presented will be very important to define its conservation status and management measures.

Multiple paternity is a shared reproductive strategy in the live-bearing surfperches (Embiotocidae) that may be associated with female fitness.

According to Bateman's principle, female fecundity is limited relative to males, setting the expectation that males should be promiscuous, while females should be choosy and select fewer mates. However, several surfperches (Embiotocidae) exhibit multiple paternity within broods indicating that females mate with multiple males throughout the mating season. Previous studies found no correlation between mating success and reproductive success (i.e., a Bateman gradient). However, by including samples from a broader range of reproductive size classes, we found evidence of a Bateman gradient in two surfperch species from distinct embiotocid clades. Using microsatellite analyses, we found that 100% of the spotfin surfperch families sampled exhibit multiple paternity (Hyperprosopon anale, the basal taxon from the only clade that has not previously been investigated) indicating that this tactic is a shared reproductive strategy among surfperches. Further, we detected evidence for a Bateman gradient in H. anale; however, this result was not significant after correction for biases. Similarly, we found evidence for multiple paternity in 83% of the shiner surfperch families (Cymatogaster aggregata) sampled. When we combine these data with a previous study on the same species, representing a larger range of reproductive size classes and associated brood sizes, we detect a Bateman gradient in shiner surfperch for the first time that remains significant after several conservative tests for bias correction. These results indicate that sexual selection is likely complex in this system, with the potential for conflicting optima between sexes, and imply a positive shift in fertility (i.e., increasing number) and reproductive tactic with respect to the mating system and number of sires throughout the reproductive life history of females. We argue that the complex reproductive natural history of surfperches is characterized by several traits that may be associated with cryptic female choice, including protracted oogenesis, uterine sac complexity, and sperm storage.

Spatio-temporal population genetic structure and mating system of red king crab (Paralithodes camtschaticus) in Alaska

Red king crab, Paralithodes camtschaticus Tilesius, 1815, an economically and culturally important species in the state of Alaska, experienced drastic reductions in abundance over large portions of their Alaskan range by 1980. Abundance of crabs in some of the most important historical fishing areas have failed to rebound, some even in the absence of fishing, highlighting the need for additional research to infer genetic structure and reproductive biology of the species that can then be used to inform management efforts. Red king crab samples were collected from eleven locations throughout Alaska ( n = 845 ), of these, six locations were sampled at least one generation apart. Results of this study suggest moderate rates of gene flow within the Gulf of Alaska/Western Alaska region. Levels of genetic differentiation among populations within Southeast Alaska were higher than seen elsewhere, and there was strong evidence of multiple distinct populations. Red king crab in Bristol Bay and in two areas in Southeast Alaska show signs of recent population bottlenecks and shifts in allele frequencies not observed in previous studies that used less polymorphic genetic markers. In addition to population genetic structure analyses, 24 female red king crab and their broods were collected for purposes of inferring mating system. There was no evidence of multiple paternity in any brood. The results of this study support continued management of distinct geographic groups within the Gulf of Alaska/Western Alaska region and suggest that finer-scale management may be beneficial in Southeast Alaska.

The secret sex lives of sage-grouse: multiple paternity and intraspecific nest parasitism revealed through genetic analysis

In lek-based mating systems only a few males are expected to obtain the majority of matings in a single breeding season and multiple mating is believed to be rare. We used 13 microsatellites to genotype greater sage-grouse (Centrocercus urophasianus) samples from 604 adults and 1206 offspring from 191 clutches (1999–2006) from Alberta, Canada, to determine paternity and polygamy (males and females mating with multiple individuals). We found that most clutches had a single father and mother, but there was evidence of multiple paternity and intraspecific nest parasitism. Annually, most males fathered only one brood, very few males fathered multiple broods, and the proportion of all sampled males in the population fathering offspring averaged 45.9%, suggesting that more males breed in Alberta than previously reported for the species. Twenty-six eggs (2.2%) could be traced to intraspecific nest parasitism and 15 of 191 clutches (7.9%) had multiple fathers. These new insights have important implications on what we know about sexual selection and the mating structure of lekking species. Key wor ds: lek, multiple paternity, nest parasitism, paternity, polygyny, sage-grouse. [Behav Ecol]