Murielle Richard

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 October 2009–30 November 2009

This article documents the addition of 411 microsatellite marker loci and 15 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Acanthopagrus schlegeli, Anopheles lesteri, Aspergillus clavatus, Aspergillus flavus, Aspergillus fumigatus, Aspergillus oryzae, Aspergillus terreus, Branchiostoma japonicum, Branchiostoma belcheri, Colias behrii, Coryphopterus personatus, Cynogolssus semilaevis, Cynoglossus semilaevis, Dendrobium officinale, Dendrobium officinale, Dysoxylum malabaricum, Metrioptera roeselii, Myrmeciza exsul, Ochotona thibetana, Neosartorya fischeri, Nothofagus pumilio, Onychodactylus fischeri, Phoenicopterus roseus, Salvia officinalis L., Scylla paramamosain, Silene latifo, Sula sula, and Vulpes vulpes. These loci were cross‐tested on the following species: Aspergillus giganteus, Colias pelidne, Colias interior, Colias meadii, Colias eurytheme, Coryphopterus lipernes, Coryphopterus glaucofrenum, Coryphopterus eidolon, Gnatholepis thompsoni, Elacatinus evelynae, Dendrobium loddigesii Dendrobium devonianum, Dysoxylum binectariferum, Nothofagus antarctica, Nothofagus dombeyii, Nothofagus nervosa, Nothofagus obliqua, Sula nebouxii, and Sula variegata. This article also documents the addition of 39 sequencing primer pairs and 15 allele specific primers or probes for Paralithodes camtschaticus.

Diversifying selection on MHC class I in the house sparrow (Passer domesticus)

Genes of the major histocompatibility complex (MHC) are the most polymorphic loci known in vertebrates. Two main hypotheses have been put forward to explain the maintenance of MHC diversity: pathogen‐mediated selection and MHC‐based mate choice. Host–parasite interactions can maintain MHC diversity via frequency‐dependent selection, heterozygote advantage, and diversifying selection (spatially and/or temporally heterogeneous selection). In this study, we wished to investigate the nature of selection acting on the MHC class I across spatially structured populations of house sparrows (Passer domesticus) in France. To infer the nature of the selection, we compared patterns of population differentiation based on two types of molecular markers: MHC class I and microsatellites. This allowed us to test whether the observed differentiation at MHC genes merely reflects demographic and/or stochastic processes. At the global scale, diversifying selection seems to be the main factor maintaining MHC diversity in the house sparrow. We found that (i) overall population differentiation at MHC was stronger than for microsatellites, (ii) MHC marker showed significant isolation by distance. In addition, the slope of the regression of FST on geographical distance was significantly steeper for MHC than for microsatellites due to a stronger pairwise differentiation between populations located at large geographical distances. These results are in agreement with the hypothesis that spatially heterogeneous selective pressures maintain different MHC alleles at local scales, possibly resulting in local adaptation.

Multiple paternity in clutches of common lizard Lacerta vivipara: data from microsatellite markers

The common lizard (Lacerta vivipara) is a small live‐bearing lacertid that reproduces once a year. In order to document the poorly known mating system of this species, we present here an assessment of multiple paternity using microsatellite markers. Paternities were established within 122 clutches belonging to two wild populations from contrasted areas and to four seminatural enclosed populations. The proportion of multiply sired clutches was found to be very high (between 50.0% and 68.2%) and similar among populations, which suggests that the mating system of this species may be insensitive to environmental and population conditions.

CONFLICT OVER MULTIPLE‐PARTNER MATING BETWEEN MALES AND FEMALES OF THE POLYGYNANDROUS COMMON LIZARDS

Abstract The optimal number of mate partners for females rarely coincides with that for males, leading to a potential sexual conflict over multiple‐partner mating. This suggests that the population sex ratio may affect multiple‐partner mating and thus multiple paternity. We investigate the relationship between multiple paternity and the population sex ratio in the polygynandrous common lizard (Lacerta vivipara). In six populations the adult sex ratio was biased toward males, and in another six populations the adult sex ratio was biased toward females, the latter corresponding to the average adult sex ratio encountered in natural populations. In males the frequency and the degree of polygyny were lower in male‐biased populations, as expected if competition among males determines polygyny. In females the frequency of polyandry was not different between treatments, and polyandrous females produced larger clutches, suggesting that polyandry might be adaptive. However, in male‐biased populations females suffered from reduced reproductive success compared to female‐biased populations, and the number of mate partners increased with female body size in polyandrous females. Polyandrous females of male‐biased populations showed disproportionately more mating scars, indicating that polyandrous females of male‐biased populations had more interactions with males and suggesting that the degree of multiple paternity is controlled by male sexual harassment. Our results thus imply that polyandry may be hierarchically controlled, with females controlling when to mate with multiple partners and male sexual harassment being a proximate determinant of the degree of multiple paternity. The results are also consistent with a sexual conflict in which male behaviors are harmful to females.

Age-specific mating strategies and reproductive senescence.

While males gain obvious direct advantages from multiple mating, the reproductive capacity of females is more constrained. The reason why polyandry evolved in females is therefore open to many conjectures. One hypothesis postulates that females gain indirect benefits by increasing the probability of siring young from high quality males. To explore this hypothesis, we used the natural variation of the reproductive value that males and females undergo through age. The age‐related variation of phenotypic performance might then induce variations in mating strategies in males and females. Using the common lizard (Lacerta vivipara) as our model system, we showed that reproductive immaturity and senescence created variability in both male and female reproductive success (including survival of offspring). Consistent with theory, males at their best‐performing phenotype adopted a polygynous strategy. These males were of an intermediate age and they produced offspring of higher viability than younger and older males. In contrast, females at their best performing phenotype, also of an intermediate age, were less polyandrous than other less‐ performing females. Middle‐aged females tended to mate with males of an intermediate age and produced litters with higher viability independently from their reproductive strategy. Males of an intermediate age enhanced their fitness by additional matings with young or old females. Young and old females increased their fitness by being more polyandrous. Polyandry therefore appears as means to seek for good males. A positive correlation between males and their partners’ fitness disagree with the idea that polyandry is the result of a sexual conflict in this species.

An Mhc class I allele associated to the expression of T-dependent immune response in the house sparrow

The major histocompatibility complex (Mhc) encodes for highly variable molecules, responsible for foreign antigen recognition and subsequent activation of immune responses in hosts. Mhc polymorphism should hence be related to pathogen resistance and immune activity, with individuals that carry either a higher diversity of Mhc alleles or one specific Mhc allele exhibiting a stronger immune response to a given antigen. Links between Mhc alleles and immune activity have never been explored in natural populations of vertebrates. To fill this gap, we challenged house sparrows (Passer domesticus) with two T-dependent antigens (phytohemagglutinin and sheep red blood cells) and examined both primary and secondary immune responses in relation to their Mhc class I genotypes. The total number of Mhc alleles had no influence on either primary or secondary response to the two antigens. One particular Mhc allele, however, was associated with an increased response to both antigens. Our results point toward a contribution of the Mhc, or of other genes in linkage disequilibrium with the Mhc, in the regulation of immune responses in a wild animal species.

Long-lasting fitness consequences of prenatal sex ratio in a viviparous lizard.

Abstract Maternal effects and early environmental conditions are important in shaping offspring developmental trajectories. For example, in laboratory mammals, the sex ratio during gestation has been shown to influence fitnessrelated traits via hormonal interaction between fetuses. Such effects have the potential to shape, or constrain, many important aspects of the organisms life, but their generality and importance in natural populations remain unknown. Using long‐term data in a viviparous lizard, Lacerta vivipara, we investigated the relationship between prenatal sex ratio and offspring growth, survival, and reproductive traits as adults. Our results show that females from male‐biased clutches grow faster, mature earlier, but have lower fecundity than females from female‐biased clutches. Furthermore, male reproduction was also affected by the sex ratio during embryonic development, with males from male‐biased clutches being more likely to successfully reproduce at age one than males from female‐biased clutches. Thus, the sex ratio experienced during gestation can have profound and long‐lasting effects on fitness in natural populations of viviparous animals, with important implications for life‐history evolution and sex allocation.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 December 2010-31 January 2011: PERMANENT GENETIC RESOURCES NOTE

This article documents the addition of 238 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alytes dickhilleni, Arapaima gigas, Austropotamobius italicus, Blumeria graminis f. sp. tritici, Cobitis lutheri, Dendroctonus ponderosae, Glossina morsitans morsitans, Haplophilus subterraneus, Kirengeshoma palmata, Lysimachia japonica, Macrolophus pygmaeus, Microtus cabrerae, Mytilus galloprovincialis, Pallisentis (Neosentis) celatus, Pulmonaria officinalis, Salminus franciscanus, Thais chocolata and Zootoca vivipara. These loci were cross‐tested on the following species: Acanthina monodon, Alytes cisternasii, Alytes maurus, Alytes muletensis, Alytes obstetricans almogavarii, Alytes obstetricans boscai, Alytes obstetricans obstetricans, Alytes obstetricans pertinax, Cambarellus montezumae, Cambarellus zempoalensis, Chorus giganteus, Cobitis tetralineata, Glossina fuscipes fuscipes, Glossina pallidipes, Lysimachia japonica var. japonica, Lysimachia japonica var. minutissima, Orconectes virilis, Pacifastacus leniusculus, Procambarus clarkii, Salminus brasiliensis and Salminus hilarii.

Condition dependence of reproductive strategy and the benefits of polyandry in a viviparous lizard

Species in which males do not contribute to reproduction beyond the provision of sperm offer good opportunities to study the potential genetic benefits that females can obtain from polyandry. Here, we report the results of a study examining the relationships between polyandry and components of female fitness in the common lizard (Lacerta vivipara). We found that polyandrous females produce larger clutches than monandrous females. Polyandrous females also lose fewer offspring during the later stages of gestation and at birth, but we did not find any relationship between polyandry and physical characteristics of viable neonates. Our results were consistent with the predictions of the intrinsic male quality hypothesis, while inbreeding avoidance and genetic incompatibility avoidance might also explain some part of the variation observed in clutch size. Moreover, the benefits of polyandry appeared to depend on female characteristics, as revealed by an interaction between reproductive strategy and female length on reproductive success. Thus, all females did not benefit equally from mating with multiple males, which could explain why polyandry and monandry coexist.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 October 2011 - 30 November 2011: PERMANENT GENETIC RESOURCES NOTEM

This article documents the addition of 139 microsatellite marker loci and 90 pairs of single‐nucleotide polymorphism sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Aglaoctenus lagotis, Costus pulverulentus, Costus scaber, Culex pipiens, Dascyllus marginatus, Lupinus nanus Benth, Phloeomyzus passerini, Podarcis muralis, Rhododendron rubropilosum Hayata var. taiwanalpinum and Zoarces viviparus. These loci were cross‐tested on the following species: Culex quinquefasciatus, Rhododendron pseudochrysanthum Hay. ssp. morii (Hay.) Yamazaki and R. pseudochrysanthum Hayata. This article also documents the addition of 48 sequencing primer pairs and 90 allele‐specific primers for Engraulis encrasicolus.