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Chris Moran

Publications and source records attributed to Chris Moran.

10 recordsLinked to original sources
PubMed2006

Phylogenetic divisions among Collared peccaries (Pecari tajacu) detected using mitochondrial and nuclear sequences.

The Collared peccary (Pecari tajacu) is one of the three extant recognised species of the family Tayassuidae, living in the Americas. To understand phylogenetic relationships among Collared peccaries, the entire mitochondrial DNA control region and cytochrome b as well as partial nuclear GPIP and PRE-1 P27, PRE-1 P642 and TYR sequences from specimens from Colombia, Argentina, Bolivia, Mexico, United States and Australian zoo animals of unknown origin were analysed. Separate and combined analyses of the mitochondrial sequences provided good resolution of Collared peccary relationships. Nuclear sequences were partially informative when combined sequence analyses were performed. Maximum Likelihood analyses of mitochondrial sequences showed that Collared peccaries clustered in two major clades, representing North-Central American and South American specimens. Collared peccaries from Colombia are paraphyletic. Statistical Parsimony analysis of combined nuclear sequences showed a distribution of DNA variants consistent with mitochondrial sequence analyses. However, there is an uncoupling of nuclear and mitochondrial sequence variation in two specimens from Colombia. The present study suggests the recent contact of isolated populations within Colombia and possible mitochondrial introgression between the North/Central clade and the South clade. Pairwise genetic distances comparison of mitochondrial sequences show that divergence between the two major clades of the Collared peccary was higher and comparable respectively with that within and between the other two recognised peccary species. Divergence between the two major clades of the Collared peccary was also higher than that observed within and even between recognised species of the Suidae family. The divergence within the major clades of the Collared peccary showed comparable values with those observed within the other two species of Tayassuidae and within six species of Suidae. The results show that the geographically widespread and phenotypically diverse Collared peccary consists of two species or at least subspecies with implications for management of wild, zoo and captive populations.

Americas↗
PubMed2006

Quantitative trait loci modifying cardiac atrial septal morphology and risk of patent foramen ovale in the mouse.

Atrial septal defect (ASD) is a common congenital heart disease (CHD) occurring in 5 to 7 per 10,000 live births. Mutations in 5 human genes (NKX2.5, TBX5, GATA4, MYHC, ACTC) are known to cause dominant ASD, but these account for a minority of cases. Human and mouse data suggest that ASD exists in an anatomical continuum with milder septal variants patent foramen ovale (PFO) and atrial septal aneurysm, strongly associated with ischemic stroke and migraine. We have previously shown in inbred mice that the incidence of PFO strongly correlates with length of the interatrial septum primum, defining a quantitative trait underlying PFO risk. To better understand genetic causation of atrial septal abnormalities, we mapped quantitative trait loci (QTL) influencing septal morphology using mouse strains (QSi5 and 129T2/SvEms) maximally informative for PFO incidence and 3 quantitative septal anatomical traits including septum primum length. [QSi5x129T2/SvEms]F2 intercross animals (n=1437) were phenotyped and a whole genome scan performed at an average 17-cM interval. Statistical methodology scoring PFO as a binary phenotype was developed as a confirmatory mapping technique. We mapped 7 significant and 6 suggestive QTL modifying quantitative phenotypes, with 4 supported by binary analysis. Quantitative traits, although strongly associated with PFO (P<0.001), correlated poorly with each other and in all but 1 case QTL for different traits were nonoverlapping. Thus, multiple anatomical processes under separate genetic control contribute to risk of PFO. Our findings demonstrate the feasibility of modeling the genetic basis of common CHD using animal genetic and genomic technologies.

Animals↗
PubMed2005

Nuclear and mitochondrial evolutionary analyses of Collared, White-lipped, and Chacoan peccaries (Tayassuidae).

The three extant peccary species, the Chacoan (Catagonus wagneri), the White-lipped (Tayassu pecari) and the Collared (Pecari tajacu), are morphologically and chromosomally distinct and confined to the New World. There is ongoing paleontological, cytogenetic, and molecular debate about phylogenetic relationships among them. To contribute to the understanding of Tayassuidae phylogeny, three mitochondrial (control region, cytochrome b, and 12S rRNA) and five nuclear (K-casein, thyrotropin, tyrosinase, and swine short interspersed nuclear elements PRE-1 P27 and P642) peccary DNA fragments were amplified, cloned and sequenced from Chacoan, White-lipped, and Collared peccaries. Phylogenetic analyses were performed using maximum likelihood and neighbor joining methods. K-casein, thyrotropin, and tyrosinase sequences did not resolve the phylogeny, while control region, cytochrome b, 12S rRNA, and PRE-1 P27 and P642 sequences were more informative in deciphering phylogenetic relationships. When pig and warthog were used as an outgroup, Chacoan and White-lipped peccaries clustered distinct from Collared peccaries. Furthermore, control region and cytochrome b sequence variation within Collared peccaries was as extreme as that between White-lipped and Chacoan peccaries, supporting subspecific and possibly even specific variation within the widely distributed Collared peccary. This study supports the existence of two independent genera within the Tayassuidae family consisting of Collared and Chacoan/White-lipped peccaries, in contrast with classical morphological taxonomy which clusters White-lipped and Collared peccaries in the genus Tayassu or which alternatively clusters the Collared peccary in the genus Dicotyles as a related sister clade of the Chacoan peccary (genus Catagonus).

Animals↗
PubMed2005

Genetic and functional evaluation of the level of inbreeding of the Westran pig: a herd with potential for use in xenotransplantation.

BACKGROUND: The Westran pig has been purposely inbred for use in xenotransplantation. The herd originated in the wild from a limited gene pool and has been inbred by repeated full-sib matings for nine generations. METHODS: The aim of this study was to evaluate the level of inbreeding by functional assays, such as bi-directional MLR and reciprocal skin grafts between herd members, and by genetic analysis using highly polymorphic genetic markers to calculate the level of inbreeding. RESULTS: The MLR between herd members were non-reactive whereas there was a prompt response to third party pig lymphocytes, indicative of a normal immune responsiveness in Westran pigs but isogenicity of the major histocompatibility complex. Skin grafts between male siblings or female sibling skin grafts on male recipients showed prolonged survival but with few exceptions did not survive beyond 100 days suggesting that by the fifth generation the Westran herd was still mismatched at minor histocompatibility antigens. This level of functional inbreeding was confirmed by microsatellite analysis of highly polymorphic markers, which showed that 52 of 53 chromosomally dispersed markers were fixed by the ninth generation. This level of fixation was consistent with 19 to 20 generations of full-sibling inbreeding. The calculated inbreeding coefficient at generation 10 was 0.98159. CONCLUSIONS: This analysis confirms that the Westran pig is highly inbred and we propose that analysis of chromosomally dispersed highly polymorphic markers is an accurate and reproducible method for assessing the level of inbreeding of a pig herd.

Aging↗
PubMed2005

Characterization of the swine major histocompatibility complex alleles at eight loci in Westran pigs.

BACKGROUND: Pigs are an important large animal model for transplantation and a potential source of xenografts. Swine leukocyte antigen (SLA) molecules are strong mediators of alloreactive and xenoreactive immune responses. We have characterized the SLA alleles of a new pig line bred for transplantation research, the Westran (Westmead Hospital transplantation) pig, described in a companion paper. METHODS: Three sixth generation inbred Westran pigs and a Large White pig control were used to assess SLA alleles. We examined the SLA-1, SLA-3, SLA-6, SLA-2, DQA1, DQB1, DRA1 and DRB1 loci using reverse transcription-polymerase chain reaction and sequencing-based method. RESULTS: All of the Westran pigs had a single allele at each locus, except for the SLA-1 locus. Typing of the SLA-1 locus in additional animals indicated that this is most likely the result of a duplication of the SLA-1 locus rather than heterozygosity. The lack of SLA heterozygosity is consistent with the previous finding of low microsatellite marker heterozygosity and is the result of both the recent deliberate inbreeding of these pigs and their derivation from a feral stock from Kangaroo Island, South Australia, established by the release of a single pair in 1803. CONCLUSIONS: After comparing DNA and protein sequences of the Westran SLA alleles with published GenBank SLA sequences, the SLA class I alleles found in the Westran pigs were all novel, while the SLA-DR and DQB1 alleles have been previously described in other pig breeds. Characterization of the SLA alleles in the Westran pigs has identified novel alleles and will be useful for designing protocols for modulation of immune responses to allografts and xenografts.

Alleles↗
PubMed2004

Development of a highly fecund inbred strain of mice.

A highly fecund inbred mouse line has been established from the Quackenbush Swiss (QS) outbred strain by full-sib inbreeding combined with selection for high number of pups born alive (NBA) and low interlitter interval (ILI). After more than 50 generations of inbreeding and selection, this line, named QSi5, has an NBA of 13.4 and an ILI of 29 days, averaged over the first four parities, and a total productivity of 50.7 NBA. With its exceptional reproductive performance, this line will be very useful in the creation of resources (including advanced intercross lines) for analysis of quantitative trait loci for a wide range of traits, and for the cost-effective creation of congenic lines.

Animals↗
PubMed2004

Phylogenetic relationships of Australian and New Zealand feral pigs assessed by mitochondrial control region sequence and nuclear GPIP genotype.

Pigs were introduced into Australia and New Zealand in the 18th and 19th centuries, with some establishing feral populations. With few records of pig introductions into these two countries, molecular phylogenetic analysis was used to assess their origins. Mitochondrial (mt) control region sequence and nuclear glucosephosphate isomerase pseudogene (GPIP) restriction fragments were used, as distinct European and Asian domestic pig and Wild Boar control region clades and GPIP genotypes can be recognised. Feral pig control region sequences clustered with either European or Asian domestic pig sequences and both Asian and European GPIP alleles were segregating. It was not possible to distinguish direct importation of Asian domestic animals into Australia and New Zealand from indirect introgression of Asian domestic sequences via Europe. However, the clustering of three feral control region sequences of pigs from northern Australia with Asian Wild Boar implies unrecorded introduction of Wild Boar or crossbred animals into Australia. However, two of these feral pigs had European GPIP alleles. In combination, analyses of control region and GPIP markers suggest that both European and Asian pigs have contributed in similar frequencies to the origins of Australian feral pigs.

Animals↗
PubMed2002

Characterizing and mapping porcine endogenous retroviruses in Westran pigs.

Since porcine endogenous retroviruses (PERVs) can infect cultured human cells, they are a potential hazard to xenotransplantation. For this reason, endogenous retroviruses from the Westran (Westmead Hospital transplantation) inbred line of pigs were analyzed by using consensus primers for the type A and type B viruses to amplify 1.8-kb envelope gene fragments. After preliminary analysis with restriction enzymes KpnI and MboI, 31 clones were sequenced. Between types A and B, five recombinant clones were identified. Fifty-five percent of clones (17 of 31) had premature stop codons within the envelope protein-encoding region. Endogenous retroviruses in Westran pigs were physically mapped by fluorescence in situ hybridization (FISH) using PERV-A and PERV-B envelope clones as probes to identify at least 32 integration sites (19 PERV-A sites and 13 PERV-B sites). The chromosomal sites of integration in the Westran strain are quite different from those in the European Large White pig. The recombinant clones suggest that defective PERVs could become infective through recombination and further that PERVs might recombine with human endogenous retroviruses in xenotransplants.

Animals↗