Sperm preservation is a useful technique for the maintenance of biological resources in experimental and domestic animals, and in wild animals. A new preservation method has been developed that enables sperm to be stored for a long time in a refrigerator at 4°C. Sperm are freeze-dried in a solution containing 10 mM Tris and 1 mM EDTA. Using this method, liquid nitrogen is not required for the storage and transportation of sperm. We demonstrate that chimpanzee, giraffe, jaguar, weasel and the long-haired rat sperm remain viable after freeze-drying. In all species, pronuclei were formed after the injection of freeze-dried sperm into the mouse oocytes. Although preliminary, these results may be useful for the future establishment of “freeze-drying zoo” to conserve wild animals.
Androgen receptor gene (AR), monoamine oxidase A gene (MAOA) and monoamine oxidase B gene (MAOB) have been found to have associations with behavioral traits, such as aggressiveness, and disorders in humans. However, the extent to which similar genetic effects might influence the behavior of wild apes is unclear. We examined the loci AR glutamine repeat (ARQ), AR glycine repeat (ARG), MAOA intron 2 dinucleotide repeat (MAin2) and MAOB intron 2 dinucleotide repeat (MBin2) in 32 wild bonobos, Pan paniscus, and compared them with those of chimpanzees, Pan troglodytes, and humans. We found that bonobos were polymorphic on the four loci examined. Both loci MAin2 and MBin2 in bonobos showed a higher diversity than in chimpanzees. Because monoamine oxidase influences aggressiveness, the differences between the polymorphisms of MAin2 and MBin2 in bonobos and chimpanzees may be associated with the differences in aggression between the two species. In order to understand the evolution of these loci and AR, MAOA and MAOB in humans and non-human primates, it would be useful to conduct future studies focusing on the potential association between aggressiveness, and other personality traits, and polymorphisms documented in bonobos.
AR, androgen receptor gene; MAOA, monoamine oxidase A gene; MAOB, monoamine oxidase B gene; ARQ, repeat locus coding glutamine in androgen receptor gene; ARG, repeat locus coding glycine in androgen receptor gene; MAin2, repeat locus in intron 2 of monoamine oxidase A gene; MBin2, repeat locus in intron 2 of monoamine oxidase B gene; PCR, polymerase chain reaction.; Bonobo; Androgen receptor; Monoamine oxidase; Genetic variation
• Premise of the study: Microsatellite markers were developed for the coastal shrub species Scaevola taccada to estimate the population genetic structure, which may reflect different seed dispersal patterns.
• Methods and Results: Thirteen microsatellite primer sets were developed for S. taccada using 454 pyrosequencing. The primer sets were tested on 64 individuals sampled from two populations in Japan. Fragments were amplified using the primers, with one to 10 alleles per locus, and the expected heterozygosity ranged from 0.00 to 0.85.
• Conclusions: These results indicate the utility of markers in S. taccada for broad estimations of the population genetic structure of this species.
454 sequencing; genetic structure; Goodeniaceae; Scaevola taccada; seed dispersal
• Premise of the study: Protorhus deflexa is an endemic large-seeded tree in Madagascar that depends heavily on insects for cross-pollination and on large-bodied frugivores for seed dispersal. Because such mutualistic relationships are vulnerable to human disturbance, the development of microsatellite markers will enhance analyses of gene flow in this tree species in degraded forests.
• Methods and Results: Nineteen microsatellite markers were developed for P. deflexa using 454 pyrosequencing. The number of alleles ranged from two to nine, and the ranges of observed and expected heterozygosities were 0.200–0.800 and 0.303–0.821, respectively. The parentage exclusion probability by the 19 loci reached 0.98583 for the first parent and 0.99971 for the second parent.
• Conclusions: These markers will be useful for studying gene flow via pollination and seed dispersal by animals and the genetic structure of P. deflexa in protected and degraded forests in Madagascar.
454 pyrosequencing; Anacardiaceae; large-seeded plants; microsatellite; Protorhus deflexa
Tonic immobility (TI) is fear-induced freezing that animals may undergo when confronted by a threat. It is principally observed in prey species as defence mechanisms. In our preliminary research, we detected large inter-individual variations in the frequency and duration of freezing behavior among newly hatched domestic chicks (Gallus gallus). In this study we aim to identify the copy number variations (CNVs) in the genome of chicks as genetic candidates that underlie the behavioral plasticity to fearful stimuli.
A total of 110 domestic chicks were used for an association study between TI responses and copy number polymorphisms. Array comparative genomic hybridization (aCGH) was conducted between chicks with high and low TI scores using an Agilent 4×180 custom microarray. We specifically focused on 3 genomic regions (>60 Mb) of chromosome 1 where previous quantitative trait loci (QTL) analysis showed significant F-values for fearful responses.
ACGH successfully detected short CNVs within the regions overlapping 3 QTL peaks. Eleven of these identified loci were validated by real-time quantitative polymerase chain reaction (qPCR) as copy number polymorphisms. Although there wkas no significant p value in the correlation analysis between TI scores and the relative copy number within each breed, several CNV loci showed significant differences in the relative copy number between 2 breeds of chicken (White Leghorn and Nagoya) which had different quantitative characteristics of fear-induced responses.
Our data shows the potential CNVs that may be responsible for innate fear response in domestic chicks.
Oceanic island ecosystems are vulnerable to the introduction of alien species, and they provide a habitat for many endangered species. Knowing the diet of an endangered animal is important for appropriate nature restoration efforts on oceanic islands because introduced species may be a major component of the diets of some endangered species. DNA barcoding techniques together with next-generation sequencing may provide more detailed information on animal diets than other traditional methods. We performed a diet analysis using 48 fecal samples from the critically endangered red-headed wood pigeon that is endemic to the Ogasawara Islands based on chloroplast trnL P6 loop sequences. The frequency of each detected plant taxa was compared with a microhistological analysis of the same sample set. The DNA barcoding approach detected a much larger number of plants than the microhistological analysis. Plants that were difficult to identify by microhistological analysis after being digested in the pigeon stomachs were frequently identified only by DNA barcoding. The results of the barcoding analysis indicated the frequent consumption of introduced species, in addition to several native species, by the red-headed wood pigeon. The rapid eradication of specific introduced species may reduce the food resources available to this endangered bird; thus, balancing eradication efforts with the restoration of native food plants should be considered. Although some technical problems still exist, the trnL approach to next-generation sequencing may contribute to a better understanding of oceanic island ecosystems and their conservation.
Conservation; diet analysis; DNA barcoding; next-generation sequencer; oceanic islands; red-headed wood pigeon
Gibbons (Hylobatidae) are the most diverse group of living apes. They exist as geographically-contiguous species which diverged more rapidly than did their close relatives, the great apes (Hominidae). Of the four extant gibbon genera, the evolutionary histories of two polyspecific genera, Hylobates and Nomascus, have been the particular focus of research but the DNA sequence data used was largely derived from the maternally inherited mitochondrial DNA (mtDNA) locus.
To investigate the evolutionary relationships and divergence processes of gibbon species, particularly those of the Hylobates genus, we produced and analyzed a total of 11.5 kb DNA of sequence at 14 biparentally inherited autosomal loci. We find that on average gibbon genera have a high average sequence diversity but a lower degree of genetic differentiation as compared to great ape genera. Our multilocus species tree features H. pileatus in a basal position and a grouping of the four Sundaic island species (H. agilis, H. klossii, H. moloch and H. muelleri). We conducted pairwise comparisons based on an isolation-with-migration (IM) model and detect signals of asymmetric gene flow between H. lar and H. moloch, between H. agilis and H. muelleri, and between N. leucogenys and N. siki.
Our multilocus analyses provide inferences of gibbon evolutionary histories complementary to those based on single gene data. The results of IM analyses suggest that the divergence processes of gibbons may be accompanied by gene flow. Future studies using analyses of multi-population model with samples of known provenance for Hylobates and Nomascus species would expand the understanding of histories of gene flow during divergences for these two gibbon genera.
Species tree; Isolation with migration; Gene flow; Autosomal loci; Phylogenetic relationships; Hylobates; Nomascus; Divergence process
• Premise of the study: Microsatellite markers were developed in the perennial herb Solidago altissima from populations within its introduced range in Japan to assess its population structure and to facilitate tracking of invasion expansion.
• Methods and Results: Using 454 pyrosequencing, 16 microsatellite primer sets were developed for S. altissima. The primer sets were tested on 70 individuals sampled from three populations in Japan. The primers amplified di- and trinucleotide repeats with five to 25 alleles per locus, and the expected heterozygosity ranged from 0.46 to 0.92.
• Conclusions: These results indicate the utility of primers in S. altissima for future research on a wide range of applications, including tracking of invasion dynamics and investigating population genetics of the species.
454 sequencing; Asteraceae; invasion; polyploidy; Solidago altissima
Genetic polymorphisms in genes related to neurotransmitters or hormones affect
personality or behavioral traits in many animal species including humans. In domestic
animals, the allele frequency of such genes has been reported to be different among breeds
and it may account for breed differences in behavior. In this study, we investigated breed
differences in horses in the dopamine receptor D4 gene (DRD4), which has been reported to
affect horse personality. We collected samples from seven horse breeds including those
native to Japan and Korea, and compared the sequence of the DRD4 exon3 region among these
breeds. We found that there were two types of polymorphisms (VNTR and SNPs) in the exon3
region, and some of them seemed to be breed-specific. In addition, we found that the
allele frequency of G292A, reported to be associated with horse personality, differed
greatly between native Japanese horses and Thoroughbred horses. The frequency of the A
allele which is associated with low curiosity and high vigilance, was much lower in native
Japanese horses (Hokkaido, 0.03; Taishu, 0.08) than in Thoroughbreds (0.62). This
difference may account for breed differences in personality or behavioral traits. Further
studies of the function of these polymorphisms and their effect on behavior are
behavioral trait; breed difference; dopamine receptor D4 gene; native Japanese horse; SNP
We tested for an association between variable number of tandem repeats in the canine androgen receptor (AR) gene and personality differences in Japanese Akita Inu dogs. The polymorphic trinucleotide (CAG) repeat region coding for glutamine in exon 1 of the AR gene was genotyped using genomic DNA obtained from 171 dogs. Three alleles (23, 24 and 26 repeats) were detected, and the allele frequency differed with the coat colour. We assessed the personality profiles of 100 fawn-coloured dogs (54 males and 46 females) based on a questionnaire answered by each dog's owner. The questionnaire consisted of five sub-scales (sociability, playfulness, neuroticism, aggressiveness, distractibility), and the psychometric properties were acceptable based upon internal consistency of the subscales. We found that male dogs with a short allele conferring increased AR function had higher aggressiveness scores than male dogs with longer alleles. By contrast, no evidence was found for a relationship between AR gene variants and personality in females. To our knowledge, our findings provide the first evidence of polymorphism in the AR gene being associated with canine aggression.
aggression; androgen receptor gene; dogs; gene polymorphisms; personality
Adrenergic-receptor beta2 (ADRB2) and beta3 (ADRB3) are obesity genes that play a key role in the regulation of energy balance by increasing lipolysis and thermogenesis. The Glu27 allele in ADRB2 and the Arg64 allele in ADRB3 are associated with abdominal obesity and early onset of non-insulin-dependent diabetes mellitus (NIDDM) in many ethnic groups. Peroxisome proliferator-activated receptor γ (PPARG) is required for adipocyte differentiation. Pro12Ala mutation decreases PPARG activity and resistance to NIDDM. In humans, energy-expense alleles, Gln27 in ADRB2 and Trp64 in ADRB3, are at higher frequencies than Glu27 and Arg64, respectively, but Ala12 in PPARG is at lower frequency than Pro12. Adaptation of humans for lipolysis, thermogenesis, and reduction of fat accumulation could be considered by examining which alleles in these genes are dominant in non-human primates (NHP). All NHP (P. troglodytes, G. gorilla, P. pygmaeus, H. agilis and macaques) had energy-thrifty alleles, Gly16 and Glu27 in ADRB2, and Arg64 in ADRB3, but did not have energy-expense alleles, Arg16, Gln27 and Trp64 alleles. In PPARG gene, all NHP had large adipocyte accumulating type, the Pro12 allele.
These results indicate that a tendency to produce much more heat through the energy-expense alleles developed only in humans, who left tropical rainforests for savanna and developed new features in their heat-regulation systems, such as reduction of body hair and increased evaporation of water, and might have helped the protection of entrails from cold at night, especially in glacial periods.
The evolutionary relationships of closely related species have long been of interest to biologists since these species experienced different evolutionary processes in a relatively short period of time. Comparison of phylogenies inferred from DNA sequences with differing inheritance patterns, such as mitochondrial, autosomal, and X and Y chromosomal loci, can provide more comprehensive inferences of the evolutionary histories of species. Gibbons, especially the genus Hylobates, are particularly intriguing as they consist of multiple closely related species which emerged rapidly and live in close geographic proximity. Our current understanding of relationships among Hylobates species is largely based on data from the maternally-inherited mitochondrial DNAs (mtDNAs).
To infer the paternal histories of gibbon taxa, we sequenced multiple Y chromosomal loci from 26 gibbons representing 10 species. As expected, we find levels of sequence variation some five times lower than observed for the mitochondrial genome (mtgenome). Although our Y chromosome phylogenetic tree shows relatively low resolution compared to the mtgenome tree, our results are consistent with the monophyly of gibbon genera suggested by the mtgenome tree. In a comparison of the molecular dating of divergences and on the branching patterns of phylogeny trees between mtgenome and Y chromosome data, we found: 1) the inferred divergence estimates were more recent for the Y chromosome than for the mtgenome, 2) the species H. lar and H. pileatus are monophyletic in the mtgenome phylogeny, respectively, but a H. pileatus individual falls into the H. lar Y chromosome clade.
Based on the ~6.4 kb of Y chromosomal DNA sequence data generated for each of the 26 individuals in this study, we provide molecular inferences on gibbon and particularly on Hylobates evolution complementary to those from mtDNA data. Overall, our results illustrate the utility of comparative studies of loci with different inheritance patterns for investigating potential sex specific processes on the evolutionary histories of closely related taxa, and emphasize the need for further sampling of gibbons of known provenance.
Y chromosome phylogeny; Phylogenetic relationships; Divergence times; Mitochondrial genome; Gene flow
The question of whether animals possess ‘cultures’ or ‘traditions’ continues to generate widespread theoretical and empirical interest. Studies of wild chimpanzees have featured prominently in this discussion, as the dominant approach used to identify culture in wild animals was first applied to them. This procedure, the ‘method of exclusion,’ begins by documenting behavioural differences between groups and then infers the existence of culture by eliminating ecological explanations for their occurrence. The validity of this approach has been questioned because genetic differences between groups have not explicitly been ruled out as a factor contributing to between-group differences in behaviour. Here we investigate this issue directly by analysing genetic and behavioural data from nine groups of wild chimpanzees. We find that the overall levels of genetic and behavioural dissimilarity between groups are highly and statistically significantly correlated. Additional analyses show that only a very small number of behaviours vary between genetically similar groups, and that there is no obvious pattern as to which classes of behaviours (e.g. tool-use versus communicative) have a distribution that matches patterns of between-group genetic dissimilarity. These results indicate that genetic dissimilarity cannot be eliminated as playing a major role in generating group differences in chimpanzee behaviour.
culture; social learning; genetics; chimpanzees; Pan troglodytes
In the brain, serotonin production is controlled by tryptophan hydroxylase 2 (TPH2), a genotype. Previous studies found that mutations on the TPH2 locus in humans were associated with depression and studies of mice and studies of rhesus macaques have shown that the TPH2 locus was involved with aggressive behavior. We previously reported a functional single nucleotide polymorphism (SNP) in the form of an amino acid substitution, Q468R, in the chimpanzee TPH2 gene coding region. In the present study we tested whether this SNP was associated with neuroticism in captive and wild-born chimpanzees living in Japan and Guinea, respectively. Even after correcting for multiple tests (Bonferroni p = 0.05/6 = 0.008), Q468R was significantly related to higher neuroticism (β = 0.372, p = 0.005). This study is the first to identify a genotype linked to a personality trait in chimpanzees. In light of the prior studies on humans, mice, and rhesus macaques, these findings suggest that the relationship between neuroticism and TPH2 has deep phylogenetic roots.
Uniquely among hominoids, gibbons exist as multiple geographically contiguous taxa exhibiting distinctive behavioral, morphological, and karyotypic characteristics. However, our understanding of the evolutionary relationships of the various gibbons, especially among Hylobates species, is still limited because previous studies used limited taxon sampling or short mitochondrial DNA (mtDNA) sequences. Here we use mtDNA genome sequences to reconstruct gibbon phylogenetic relationships and reveal the pattern and timing of divergence events in gibbon evolutionary history.
We sequenced the mitochondrial genomes of 51 individuals representing 11 species belonging to three genera (Hylobates, Nomascus and Symphalangus) using the high-throughput 454 sequencing system with the parallel tagged sequencing approach. Three phylogenetic analyses (maximum likelihood, Bayesian analysis and neighbor-joining) depicted the gibbon phylogenetic relationships congruently and with strong support values. Most notably, we recover a well-supported phylogeny of the Hylobates gibbons. The estimation of divergence times using Bayesian analysis with relaxed clock model suggests a much more rapid speciation process in Hylobates than in Nomascus.
Use of more than 15 kb sequences of the mitochondrial genome provided more informative and robust data than previous studies of short mitochondrial segments (e.g., control region or cytochrome b) as shown by the reliable reconstruction of divergence patterns among Hylobates gibbons. Moreover, molecular dating of the mitogenomic divergence times implied that biogeographic change during the last five million years may be a factor promoting the speciation of Sundaland animals, including Hylobates species.
The MITF (microphthalmia-associated transcription factor) gene has been investigated in mice and various vertebrates but its variations and associated effects have not yet been explored much in birds. The present study describes the causal mutation B at the MITF gene responsible for the "silver" plumage colour in the Japanese quail (Coturnix japonica), and its associated effects on growth and body composition, and tests its allelism with the "blue" plumage colour mutation Bl in Gallus gallus.
The semi dominant B mutation results from a premature stop codon caused by a 2 bp deletion in exon 11 of MITF. Homozygous "white" (B/B) quail which have a white plumage also show a slightly lower growth, lower body temperature, smaller heart, and lighter pectoralis muscles but more abdominal adipose tissue than the recessive homozygous "wild-type" (+/+) and heterozygous "silver" (B/+) quail. Similar observations on cardiac and body growth were made on mice (Mus musculus) homozygous for mutations at MITF. The production of chicken-quail hybrids with a white plumage obtained by crossing Bl/+ chicken heterozygous for the blue mutation with B/B white quail indicated that the mutations were allelic.
The "silver" Japanese quail is an interesting model for the comparative study of the effects of MITF in birds and mammals. Further investigation using a chicken family segregating for the "blue" plumage and molecular data will be needed to confirm if the "blue" plumage in chicken results from a mutation in MITF.
Egg production is of critical importance in birds not only for their reproduction but also for human consumption as the egg is a highly nutritive and balanced food. Consequently, laying in poultry has been improved through selection to increase the total number of eggs laid per hen. This number is the cumulative result of the oviposition, a cyclic and repeated process which leads to a pattern over time (the egg laying curve) which can be modelled and described individually. Unlike the total egg number which compounds all variations, the shape of the curve gives information on the different phases of egg laying, and its genetic analysis using molecular markers might contribute to understand better the underlying mechanisms. The purpose of this study was to perform the first QTL search for traits involved in shaping the egg laying curve, in an F2 experiment with 359 female Japanese quail.
Eight QTL were found on five autosomes, and six of them could be directly associated with egg production traits, although none was significant at the genome-wide level. One of them (on CJA13) had an effect on the first part of the laying curve, before the production peak. Another one (on CJA06) was related to the central part of the curve when laying is maintained at a high level, and the four others (on CJA05, CJA10 and CJA14) acted on the last part of the curve where persistency is determinant. The QTL for the central part of the curve was mapped at the same position on CJA06 than a genome-wide significant QTL for total egg number detected previously in the same F2.
Despite its limited scope (number of microsatellites, size of the phenotypic data set), this work has shown that it was possible to use the individual egg laying data collected daily to find new QTL which affect the shape of the egg laying curve. Beyond the present results, this new approach could also be applied to longitudinal traits in other species, like growth and lactation in ruminants, for which good marker coverage of the genome and theoretical models with a biological significance are available.
By comparing the quail genome with that of chicken, chromosome rearrangements that have occurred in these two galliform species over 35 million years of evolution can be detected. From a more practical point of view, the definition of conserved syntenies helps to predict the position of genes in quail, based on information taken from the chicken sequence, thus enhancing the utility of this species in biological studies through a better knowledge of its genome structure. A microsatellite and an Amplified Fragment Length Polymorphism (AFLP) genetic map were previously published for quail, as well as comparative cytogenetic data with chicken for macrochromosomes. Quail genomics will benefit from the extension and the integration of these maps.
The integrated linkage map presented here is based on segregation analysis of both anonymous markers and functional gene loci in 1,050 quail from three independent F2 populations. Ninety-two loci are resolved into 14 autosomal linkage groups and a Z chromosome-specific linkage group, aligned with the quail AFLP map. The size of linkage groups ranges from 7.8 cM to 274.8 cM. The total map distance covers 904.3 cM with an average spacing of 9.7 cM between loci. The coverage is not complete, as macrochromosome CJA08, the gonosome CJAW and 23 microchromosomes have no marker assigned yet. Significant sequence identities of quail markers with chicken enabled the alignment of the quail linkage groups on the chicken genome sequence assembly. This, together with interspecific Fluorescence In Situ Hybridization (FISH), revealed very high similarities in marker order between the two species for the eight macrochromosomes and the 14 microchromosomes studied.
Integrating the two microsatellite and the AFLP quail genetic maps greatly enhances the quality of the resulting information and will thus facilitate the identification of Quantitative Trait Loci (QTL). The alignment with the chicken chromosomes confirms the high conservation of gene order that was expected between the two species for macrochromosomes. By extending the comparative study to the microchromosomes, we suggest that a wealth of information can be mined in chicken, to be used for genome analyses in quail.
Panda (s) is an autosomal recessive mutation, which displays overall white plumage color with spots of wild-type plumage in the Japanese quail (Coturnix japonica). In a previous study, the s locus was included in the same linkage group as serum albumin (Alb) and vitamin-D binding protein (GC) which are mapped on chicken (Gallus gallus) chromosome 4 (GGA4). In this study, we mapped the s locus on the microsatellite linkage map of the Japanese quail by linkage analysis.
Segregation data on the s locus were obtained from three-generation families (n = 106). Two microsatellite markers derived from the Japanese quail chromosome 4 (CJA04) and three microsatellite markers derived from GGA4 were genotyped in the three-generation families. We mapped the s locus between GUJ0026 and ABR0544 on CJA04. By comparative mapping with chicken, this locus was mapped between 10.0 Mb and 14.5 Mb region on GGA4. In this region, the endothelin receptor B subtype 2 gene (EDNRB2), an avian-specific paralog of the mammalian endothelin receptor B gene (EDNRB), is located. Because EDNRB is responsible for aganglionic megacolon and spot coat color in mouse, rat and equine, EDNRB2 is suggested to be a candidate gene for the s locus.
The s locus and the five microsatellite markers were mapped on CJA04 of the Japanese quail. EDNRB2 was suggested to be a candidate gene for the s locus.
The Japanese quail (Coturnix japonica) is both an animal model in biology and a commercial bird for egg and meat production. Modern research developments with this bird, however, have been slowed down by the limited information that is available on the genetics of the Japanese quail. Recently, quail genetic maps with microsatellites and AFLP have been produced which open the way to comparative works with the chicken (Gallus gallus), and to QTL detection for a variety of traits. The purpose of this work was to detect for the first time QTL for commercial traits and for more basic characters in an F2 experiment with 434 female quail, and to compare the nature and the position of the detected QTL with those from the first chicken genome scans carried out during the last few years.
Genome-wide significant or suggestive QTL were found for clutch length, body weight and feed intake on CJA01, age at first egg and egg number on CJA06, and eggshell weight and residual feed intake on CJA20, with possible pleiotropy for the QTL affecting body weight and feed intake, and egg number and age at first egg. A suggestive QTL was found for tonic immobility on CJA01, and chromosome-wide significant QTL for body temperature were detected on CJA01 and CJA03. Other chromosome-wide significant QTL were found on CJA02, CJA05, CJA09 and CJA14. Parent-of-origin effects were found for QTL for body weight and feed intake on CJA01.
Despite its limited length, the first quail microsatellite map was useful to detect new QTL for rarely reported traits, like residual feed intake, and to help establish some correspondence between the QTL for feed intake, body weight and tonic immobility detected in the present work and those reported on GGA01 in the chicken. Further comparative work is now possible in order to better estimate and understand the genetic similarities and differences of these two Phasianidae species.
In line with the Gifu University's initiative to map the Japanese quail genome, a total of 100 Japanese quail microsatellite markers isolated in our laboratory were evaluated in a population of 20 unrelated quails randomly sampled from a colony of wild quail origin. Ninety-eight markers were polymorphic with an average of 3.7 alleles per locus and a mean heterozygosity of 0.423. To determine the utility of these markers for comparative genome mapping in Phasianidae, cross-species amplification of all the markers was tested with chicken and guinea fowl DNA. Amplification products similar in size to the orthologous loci in quail were observed in 42 loci in chicken and 20 loci in guinea fowl. Of the cross-reactive markers, 57.1% in chicken and 55.0% in guinea fowl were polymorphic when tested in 20 birds from their respective populations. Five of 15 markers that could cross-amplify Japanese quail, chicken, and guinea fowl DNA were polymorphic in all three species. Amplification of orthologous loci was confirmed by sequencing 10 loci each from chicken and guinea fowl and comparing with them the corresponding quail sequence. The microsatellite markers reported would serve as a useful resource base for genetic mapping in quail and comparative mapping in Phasianidae.
Japanese quail; microsatellite loci; chicken; guinea fowl; comparative genetic map