Chimpanzee Personality and the Arginine Vasopressin Receptor 1A Genotype.

Polymorphisms of the arginine vasopressin receptor 1a (AVPR1a) gene have been linked to various measures related to human social behavior, including sibling conflict and agreeableness. In chimpanzees, AVPR1a polymorphisms have been associated with traits important for social interactions, including sociability, joint attention, dominance, conscientiousness, and hierarchical personality dimensions named low alpha/stability, disinhibition, and negative emotionality/low dominance. We examined associations between AVPR1a and six personality domains and hierarchical personality dimensions in 129 chimpanzees (Pan troglodytes) living in Japan or in a sanctuary in Guinea. We fit three linear and three animal models. The first model included genotype, the second included sex and genotype, and the third included genotype, sex, and sex × genotype. All personality phenotypes were heritable. Chimpanzees possessing the long form of the allele were higher in conscientiousness, but only in models that did not include the other predictors; however, additional analyses suggested that this may have been a consequence of study design. In animal models that included sex and sex × genotype, chimpanzees homozygous for the short form of the allele were higher in extraversion. Taken with the findings of previous studies of chimpanzees and humans, the findings related to conscientiousness suggest that AVPR1a may be related to lower levels of impulsive aggression. The direction of the association between AVPR1a genotype and extraversion ran counter to what one would expect if AVPR1a was related to social behaviors. These results help us further understand the genetic basis of personality in chimpanzees.

Genome-wide DNA markers to support genetic management for domestication and commercial production in a large rodent, the Ghanaian grasscutter (Thryonomys swinderianus).

Domestication and commercial production of the grasscutter, Thryonomys swinderianus, a large rodent, represents an important opportunity to secure sustainable animal protein for local communities in West Africa. To support production, DNA markers are required for population diversity assessment, pedigree analysis and marker-assisted selection. This study reports the application of double-digest RAD sequencing to simultaneously discover and genotype SNP markers in 24 wild and recently domesticated grasscutters. An initial panel of 1209 SNP loci was characterised from a total of more than 21 000 candidate loci containing single SNPs. This genome-wide resource represents the first application of its type to commercial production of a large rodent for food and advances the use of agricultural genomics in Ghana.

Evidence for the effect of serotonin receptor 1A gene (HTR1A) polymorphism on tractability in Thoroughbred horses.

Tractability, or how easily animals can be trained and controlled, is an important behavioural trait for the management and training of domestic animals, but its genetic basis remains unclear. Polymorphisms in the serotonin receptor 1A gene (HTR1A) have been associated with individual variability in anxiety-related traits in several species. In this study, we examined the association between HTR1A polymorphisms and tractability in Thoroughbred horses. We assessed the tractability of 167 one-year-old horses reared at a training centre for racehorses using a questionnaire consisting of 17 items. A principal components analysis of answers contracted the data to five principal component (PC) scores. We genotyped two non-synonymous single nucleotide polymorphisms (SNPs) in the horse HTR1A coding region. We found that one of the two SNPs, c.709G>A, which causes an amino acid change at the intracellular region of the receptor, was significantly associated with scores of four of five PCs in fillies (all Ps < 0.05) and one PC in colts (P < 0.01). Horses carrying an A allele at c.709G>A showed lower tractability. This result provides the first evidence that a polymorphism in a serotonin-related gene may affect tractability in horses with the effect partially different depending on sex.

Copy number variations in the amylase gene (AMY2B) in Japanese native dog breeds.

A recent study suggested that increased copy numbers of the AMY2B gene might be a crucial genetic change that occurred during the domestication of dogs. To investigate AMY2B expansion in ancient breeds, which are highly divergent from modern breeds of presumed European origins, we analysed copy numbers in native Japanese dog breeds. Copy numbers in the Akita and Shiba, two ancient breeds in Japan, were higher than those in wolves. However, compared to a group of various modern breeds, Akitas had fewer copy numbers, whereas Shibas exhibited the same level of expansion as modern breeds. Interestingly, average AMY2B copy numbers in the Jomon-Shiba, a unique line of the Shiba that has been bred to maintain their appearance resembling ancestors of native Japanese dogs and that originated in the same region as the Akita, were lower than those in the Shiba. These differences may have arisen from the earlier introduction of rice farming to the region in which the Shiba originated compared to the region in which the Akita and the Jomon-Shiba originated. Thus, our data provide insights into the relationship between the introduction of agriculture and AMY2B expansion in dogs.

Genetic effects of demographic bottleneck and recovery in Kinkazan Island and mainland populations of Japanese macaques (Macaca fuscata).

Populations of Japanese macaques were significantly reduced in most areas from the 1900s to the 1960s and then recovered mainly in the northeastern part of Honshu. A drastic reduction in population size reduces genetic variability through a bottleneck effect. Demographic expansion after the reduction that accumulates new mutations can reduce the bottleneck effects or drive the recovery of genetic variability. We examined the genetic status of a small island population (Kinkazan Island) and a larger mainland population (southern Tohoku) of Japanese macaques that experienced recent demographic bottlenecks and recovery using eight microsatellite loci. The two populations were significantly genetically different from each other. The Kinkazan population exhibited lower genetic variability, remarkable evidence of bottleneck (i.e., significant heterozygosity excess and lower frequency of rare alleles), and a considerably smaller effective population size based on genetic data than based on the current census size. These results indicate that the genetic status has not completely recovered from the demographic bottleneck despite a full recovery in census size on Kinkazan Island. New mutations might rarely have accumulated because of the small carrying capacity of the island. Therefore, the genetic variability of the population would have been restrained by the severe bottleneck size, small carrying capacity, and long-term isolation. On the other hand, the bottleneck effect seems to be limited in the southern Tohoku population considering higher genetic variability, non-significant heterozygosity excess in many mutation conditions, and the highest frequency of rare alleles.

An approach to canine behavioural genetics employing guide dogs for the blind.

The purpose of this study was to attempt to find related variables of the canine genome with behavioural traits of dogs maintained and tested in a guide dog facility which provided a relatively uniform environment. The study involved 81 Labrador Retrievers that were being trained as guide dogs. Each dog was taken on walk-out sessions in which the trainer weekly recorded observations that were related to behavioural traits. The records were subjected to key-word analysis of 14 behaviour-related words. A factor analysis on the appearance rate of the 14 key words or phrases resulted in the extraction of six factors that accounted for 67.4% of the variance. Factor 1, referred to as aggressiveness, was significantly related to the success or failure of the dog in qualifying as a guide dog, and was also related to the variable of litter identification. Factor 2, referred to as distraction, was related to the variable of trainer. Factor 3, activity level, was related to the variable of sex, and was significantly related to the polymorphisms of c.471T>C in the solute carrier family 1 (neuronal/epithelial high affinity glutamate transporter) member 2 gene and c.216G>A in the catechol-O-methyltransferase gene. The involvement of polymorphisms c.471T>C and c.216G>A in behavioural patterns related to activity level is similar to comparable genetic studies in other mammalian species. These results contribute to a greater understanding of the role of these genes in behaviour.

Association analysis between canine behavioural traits and genetic polymorphisms in the Shiba Inu breed.

The relationships between behavioural trait data and the genotype of 15 polymorphisms in eight neurotransmitter-related genes were analysed in 77 dogs of the Shiba Inu breed, an indigenous Japanese dog. The data were obtained from a 26-item questionnaire on the dog's behaviour, distributed to the dog's owners, through veterinary hospitals and the Shiba Inu breed magazine. A factor analysis of the questionnaire items extracted eight factors accounting for 66.8% of the variance. An association analysis between these factors and genetic polymorphisms indicated that the polymorphism of c.471T>C in the solute carrier family 1 (neuronal/epithelial high-affinity glutamate transporter) member 2 (SLC1A2) gene was significantly associated with Factor 1, referred to as 'aggression to strangers'. This association remained stable in separate analyses of data from surveys obtained from the hospitals and those obtained from the magazine. The results suggest that the c.471T>C polymorphism is associated with some types of aggressive behaviour in the Shiba Inu. Further studies using other dog breeds are necessary to extend these findings to dogs in general.

Effects of the dominant lethal yellow mutation on reproduction, growth, feed consumption, body temperature, and body composition of the Japanese quail.

Wild-type Japanese quail were compared with full-sibs with a yellow plumage color determined by an autosomal dominant mutation (Y), which is lethal when homozygous. These quail have wheat-straw yellow-colored feathers. Early growth was slower in yellow quail that had 2.4% lower BW than wild-type quail (149.3 g vs. 153.0 g) at 28 d of age. The BW, however, was similar for yellow and wild-type males at 35 d, and it remained so throughout the last part of the growth of the quail monitored until the age of 120 d, as indicated by the very close parameters of the monomolecular growth curve [BW= A - B exp(-kt)] obtained for the 2 groups. Yellow plumage color was also associated with a more difficult adaptation to housing (measured by temporary BW loss) in individual cages and to a significantly 0.2 degrees C lower body temperature at 42 d, but feed consumption and residual feed intake were similar for the 2 plumage color phenotypes. Breast and liver weights were similar in the 2 groups, but abdominal fat was 24% higher (4.66 vs. 3.76 g) in yellow quail. There is some association between the correlated effects of the Y gene in quail and those of the lethal mutation A(y) at the agouti locus in the mouse.

Sequence and functional properties of African green monkey CD4 silencer.

We reported previously that in African green monkey (AGM) CD4 lymphocytes, CD4 mRNA expression undergoes a decrease following in vitro activation, and CD4 cells are therefore subject to loss of CD4 expression on the cell surface. To examine the transcriptional regulation of the CD4 gene in this species. we analyzed the CD4 silencer, which has been identified as a regulatory element responsible for the down regulation of CD4 transcription in CD8 cell lineage cells. Sequence analysis indicated that the CD4 silencer of the AGM was highly homologous to that of humans. However, two nucleotide substitutions were present in one of the nuclear protein binding sites, which was characterized as the FP II site having a strong enhancing effect on transgene expression in CD4 cells. By performing transient transfection assays. we found that the enhancing activities of the CD4 silencer or FP II-containing fragment of the AGM were greatly reduced in a human CD4 cell line as compared to those of human materials. The CD4 mRNA level was significantly decreased in the human CD4 cell line when synthetic oligonucleotide corresponding to the human FP II sequence was added to the culture. These observations imply that FP II-protein interaction might be required for the maintenance of sufficient expression of the CD4 gene, and the enhancing activity mediated by the above interaction might be decreased in the AGM CD4 silencer, due probably to the nucleotide changes occurring at the FP II site.

Molecular cloning and characterization of cynomolgus monkey Fas.

The Fas-FasL system plays a crucial role in the maintenance of homeostasis in the immune system. To characterize the Fas/FasL system in macaque monkeys that are commonly used as experimental primates, we cloned and sequenced Fas cDNA derived from the cynomolgus monkey. The predicted amino acid sequence consists of 331 amino acids with a calculated molecular weight of 35,800. The extracellular cysteine-rich motif of cynomolgus Fas is highly homologous to that of humans (96%), whereas the intracellular death domain has a relatively low similarity to that of humans (86%). An agonistic Fas antibody (CH11) or cynomolgus FasL induced apoptosis in human Fas-transfected K562 cells in the presence of CHX but not in the cynomolgus Fas transfectant. CH11 and FasL failed to trigger apoptosis in the transfectant expressing human-cynomolgus chimera Fas consisting mostly of human-derived extracellular region and cynomolgus-derived intracellular portion. On the other hand, the transfectant expressing cynomolgus-human chimera Fas with human-derived intracellular region underwent apoptosis upon exposure to FasL. In addition, the virus-transformed, Fas-positive cynomolgus monkey cell line was highly sensitive to FasL. These findings suggest that the lack of apoptotic activity in the cynomolgus Fas transfectant in the human cell line might be related to the species-specific structure of Fas, especially of the death domain.

Allelic variation of the D4 dopamine receptor polymorphic region in two dog breeds, Golden retriever and Shiba.

The D4 dopamine receptor (D4DR) polymorphic region, which is possibly related to the personality trait known as novelty seeking in humans, was examined in 34 dogs from two breeds (Golden retriever and the Japanese indigenous breed, Shiba) by the polymerase chain reaction (PCR), and the DNA sequences of each allele were determined. The polymorphic region of the dog D4DR gene was composed of 39- and 12- base pair (bp) units, and four alleles (A-D) were identified based on the number and/or order of these units. Intra- and inter-breed allele variations were observed. The frequency of the short A allele was dominant (78.9%) in the Golden retriever, while the long D allele was most common (46.7%) in the Shiba. These findings suggested that the allele frequency varied significantly between different breeds, and that analysis of the polymorphism in D4DR might be of use for understanding the behavioral traits of dogs.

Endothelin receptor B2 (EDNRB2) is associated with the panda plumage colour mutation in Japanese quail.

The panda mutant in Japanese quail (Coturnix japonica) displays spots of wild-type plumage on a white background and is controlled by an autosomal recessive allele (s). The dotted white is controlled by a third allele (s(dw)) of the s locus with s(dw)/s(dw) quail having less pigmentation than s/s quail. We mapped the s locus to the Japanese quail chromosome 4 (CJA04) in a previous study. The orthologous region of the chicken (Gallus gallus) genome includes endothelin receptor B2 (EDNRB2), an avian-specific paralog of endothelin receptor B (EDNRB). EDNRB mutations in mammals retard the migration of neural crest cells (NCCs), which results in a spotted coat colour and an enteric nervous defect. In the present study, we investigated the association between the s locus and EDNRB2 in Japanese quail. Sequence comparison among transcripts from livers of wild-type, panda and dotted white quail revealed a nucleotide substitution (c.995G>A) leading to a p.R332H amino acid change that was specific to panda, whereas no amino acid substitution was found in dotted white birds. The amino acid position 332 is located in the sixth transmembrane domain and is highly conserved in both avian and mammalian endothelin receptors. The A allele at nucleotide position 995 was specific to panda (s/s) birds among 10 strains, and was mapped to the same chromosomal region as the s locus. Quantitative RT-PCR revealed that EDNRB2 transcripts were reduced in both panda and dotted white mutants compared with wild-type. However, there was no difference between the early embryos of wild-type and panda with respect to the migration of NCCs. The genetic association of EDNRB2 with plumage colour in birds was found for the first time in this study.

A chicken linkage map based on microsatellite markers genotyped on a Japanese Large Game and White Leghorn cross.

A detailed linkage map is necessary for efficient detection of quantitative trait loci (QTL) in chicken resource populations. In this study, microsatellite markers isolated from a (CA)n-enriched library (designated as ABR Markers) were mapped using a population developed from a cross between Japanese Game and White Leghorn chickens. In total, 296 markers including 193 ABR, 43 MCW, 31 ADL, 22 LEI, 3 HUJ, 2 GCT, 1 UMA and 1 ROS were mapped by linkage to chicken chromosomes 1-14, 17-21, 23, 24, 26-28 and Z. In addition, five markers were assigned to the map based on the chicken draft genomic sequence, bringing the total number of markers on the map to 301. The resulting linkage map will contribute to QTL mapping in chicken.

Mapping of plumage colour and blood protein loci on the microsatellite linkage map of the Japanese quail.

The objective of this work was to map classical markers (plumage colours and blood proteins) on the microsatellite linkage map of the Japanese quail (Coturnix japonica). The segregation data on two plumage colours and three blood proteins were obtained from 25 three-generation families (193 F2 birds). Linkage analysis was carried out for these five classical markers and 80 microsatellite markers. A total of 15 linkage groups that included the five classical loci and 69 of the 80 microsatellite markers were constructed. Using the BLAST homology search against the chicken genome sequence, three quail linkage groups, QL8, QL10 and QL13, were suggested to be homologous to chicken chromosomes GGA9, GGA20 and GGA24, respectively. Two plumage colour loci, black at hatch (Bh) and yellow (Y), and the three blood protein loci, transferrin (Tf), haemoglobin (Hb-1) and prealbumin-1 (Pa-1), were assigned to CJA01, QL10, QL8, CJA14 and QL13, respectively.

Type XVIII collagen is newly transcribed during bovine adipogenesis.

To isolate candidate genes concerned with bovine adipocyte differentiation, we have constructed a subtraction cDNA library from a clonal bovine intramuscular preadipocyte (BIP) cell line. We have isolated a set of cDNA clones whose respective mRNA levels are upregulated during the differentiation of BIP cells. The sequence of one subtracted cDNA fragment was highly homologous to that of mouse type XVIII collagen. Northern blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR) showed that collagen XVIII gene expression increased during adipocyte differentiation. The collagen XVIII gene was also highly expressed in fat tissue. Although its function is unclear, these expression patterns indicate that type XVIII collagen may be associated with adipocyte differentiation in cattle.

An African green monkey lacking peripheral CD4 lymphocytes that retains helper T cell activity and coexists with SIVagm.

Natural infection with simian immunodeficiency virus (SIV) is known to occur in the African green monkey (AGM). The actual onset of the disease has not been recognized in SIVagm infected AGM, and the precise reason for such apathogenicity in the AGM remains unclear. We reported previously that AGM peripheral CD4 lymphocytes underwent a peculiar differentiation from CD4+ to CD4- cells after in vitro activation, and we inferred that the AGM does not fall into a fatal immunodeficient state because of the generation of CD4- helper T cells in vivo. To evaluate this possibility, we examined the relationship between CD4 expression and helper T cell activity in the naturally infected AGM. We identified a healthy monkey almost lacking CD4 T cells in the periphery. This AGM showed no signs and symptoms of immunodeficiency and retained a helper T cell activity in antibody production comparable to those of CD4+ AGMs. In addition, SIVagm could be isolated from CD8+ lymphocytes in the CD4- AGM. These observations suggest that a unique host-virus adaptation has developed in the AGM, and may be helpful in explaining the fundamental reason for the apathogenicity occurring in this monkey.

Genetic analyses of plumage color mutations on the Z chromosome of Japanese quail.

Genetic analyses were performed with four sex-linked plumage color mutations (roux, brown, imperfect albino, and cinnamon) in Japanese quail (Coturnix japonica). Roux and brown quail have similar plumage color, but plumage of roux quail is paler. Pure, F1 and F2 matings were carried out with roux and brown stocks, and 357, 338, and 273 progeny with either roux or brown plumage color were obtained from each mating type, respectively. These allelism tests showed that mutations for roux and brown colors were alleles (*R and *B) from the same locus BR, and that BR*B was dominant over BR*R. Two alleles at the AL locus, AL*A (imperfect albino) and AL*C (cinnamon) were used to estimate the recombination frequency between the BR and AL loci on the Z chromosome. It was estimated to be 38.1+/-1.0% based on 4615 chicks from the test crosses.

Involvement of granzyme B expression in the enhancement of natural killer activity by beta-endorphin.

Beta-Endorphin has been reported to enhance natural killer (NK) activity in vitro. However, few studies have examined the precise regulation of the cytolytic stage of NK cells. We therefore investigated the regulation by beta-endorphin of cytotoxicity-associated molecules such as granzyme B, perforin, and Fas ligand (FasL) in human CD16(+) NK cells. On semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) assay, the granzyme B mRNA level apparently increased in CD16(+) NK cells from high responding subjects having ratios >1.5 for the LU(30) ratio. An increase in intracellular granzyme B molecules was also detected in CD16(+) NK cells by flow cytometry. On the other hand, perforin and FasL appeared not to be involved in regulation by beta-endorphin. These findings suggest that up-regulation of granzyme B expression may be involved in the enhancement of NK activity by beta-endorphin.

U5 monoclonal antibody identifies a novel lymphocyte surface antigen preferentially expressed in human circulating natural killer cells with high cytotoxic activity.

U5 monoclonal antibody (mAb), developed against Japanese monkey lymphocytes, identified a glycoprotein of 32 000 MW that is expressed in a subset of human circulating natural killer (NK) cells. The distribution of U5 molecules was restricted among CD16+ cells, and U5 antigen was preferentially expressed in the CD38+ subset. U5+ CD16+ CD56+ cells were highly active on NK assay against K562 target cells. Variations in cytolytic activities and mRNA expression of perforin, granzyme B and Fas ligand (FasL) were observed in U5- CD16+ CD56+ cells depending on the donor. We found that in some donors, a phenotypically mature (CD16+ CD56+) but functionally immature subset was present in the peripheral circulation. The U5- CD16+ CD56+ cells of some donors exhibited negligible cytolytic activity with no detectable expression of the above mRNAs, whereas those of the other donors had a significant but lower cytolytic activity with a reduced expression of granzyme B mRNA as compared with those of U5+ CD16+ CD56+ cells. Concanavalin A (Con A) stimulation induced an expression of U5 antigen in U5- CD16+ CD56+ cells accompanied by an up-regulation of granzyme B mRNA expression. These findings suggest that U5 antigen may be a novel molecule involved in the maturation or differentiation of human circulating NK cells.

A first-generation microsatellite linkage map of the Japanese quail.

A linkage map of the Japanese quail (Coturnix japonica) genome was constructed based upon segregation analysis of 72 microsatellite loci in 433 F(2) progeny of 10 half-sib families obtained from a cross between two quail lines of different genetic origins. One line was selected for long duration of tonic immobility, a behavioural trait related to fearfulness, while the other was selected based on early egg production. Fifty-eight of the markers were resolved into 12 autosomal linkage groups and a Z chromosome-specific linkage group, while the remaining 14 markers were unlinked. The linkage groups range from 8 cM (two markers) to 206 cM (16 markers) and cover a total map distance of 576 cM with an average spacing of 10 cM between loci. Through comparative mapping with chicken (Gallus gallus) using orthologous markers, we were able to assign linkage groups CJA01, CJA02, CJA05, CJA06, CJA14 and CJA27 to chromosomes. This map, which is the first in quail based solely on microsatellites, is a major step towards the development of a quality molecular genetic map for this valuable species. It will provide an important framework for further genetic mapping and the identification of quantitative trait loci controlling egg production and fear-related behavioural traits in quail.