Analysis of genetic diversity in Bolivian llama populations using microsatellites.

South American camelids (SACs) have a major role in the maintenance and potential future of rural Andean human populations. More than 60% of the 3.7 million llamas living worldwide are found in Bolivia. Due to the lack of studies focusing on genetic diversity in Bolivian llamas, this analysis investigates both the genetic diversity and structure of 12 regional groups of llamas that span the greater part of the range of distribution for this species in Bolivia. The analysis of 42 microsatellite markers in the considered regional groups showed that, in general, there were high levels of polymorphism (a total of 506 detected alleles; average PIC across per marker: 0.66), which are comparable with those reported for other populations of domestic SACs. The estimated diversity parameters indicated that there was high intrapopulational genetic variation (average number of alleles and average expected heterozygosity per marker: 12.04 and 0.68, respectively) and weak genetic differentiation among populations (FST range: 0.003-0.052). In agreement with these estimates, Bolivian llamas showed a weak genetic structure and an intense gene flow between all the studied regional groups, which is due to the exchange of reproductive males between the different flocks. Interestingly, the groups for which the largest pairwise FST estimates were observed, Sud Lípez and Nor Lípez, showed a certain level of genetic differentiation that is probably due to the pattern of geographic isolation and limited communication infrastructures of these southern localities. Overall, the population parameters reported here may serve as a reference when establishing conservation policies that address Bolivian llama populations.

Parental knowledge and attitudes towards dental radiography for children.

BACKGROUND: Radiographs are an essential part of most clinical dental examinations and diagnoses. The aim of the study was to assess the knowledge and attitudes of parents towards dental radiographs for their children. METHODS: A 21-item questionnaire, covering parental level of radiation knowledge and socio-demographics was applied. Sliding scales were used to assess attitude towards dental radiographs. RESULTS: There were 1467 questionnaires distributed between five primary schools in the Perth (Western Australia) metropolitan area, with 309 surveys (21%) returned for collection. Most parents displayed a low level of knowledge, but had a positive attitude towards dental radiographs. Parents with children who have previously had dental radiographs perceived dental radiographs as 'good', 'useful' and 'pleasant'. A higher level of education and parents with children who have previously had radiographs were significantly associated with a higher level of knowledge about dental radiography. Parents who had higher scores on questions assessing radiation knowledge were more likely to perceive dental radiographs as 'safe' and 'beneficial'. CONCLUSIONS: Most parents have a positive attitude towards dental radiographs on their children. However, the majority of parents lack knowledge regarding dental radiography, especially regarding the risks involved.

Analysis of mitochondrial DNA in Bolivian llama, alpaca and vicuna populations: a contribution to the phylogeny of the South American camelids.

The objectives of this work were to assess the mtDNA diversity of Bolivian South American camelid (SAC) populations and to shed light on the evolutionary relationships between the Bolivian camelids and other populations of SACs. We have analysed two different mtDNA regions: the complete coding region of the MT-CYB gene and 513 bp of the D-loop region. The populations sampled included Bolivian llamas, alpacas and vicunas, and Chilean guanacos. High levels of genetic diversity were observed in the studied populations. In general, MT-CYB was more variable than D-loop. On a species level, the vicunas showed the lowest genetic variability, followed by the guanacos, alpacas and llamas. Phylogenetic analyses performed by including additional available mtDNA sequences from the studied species confirmed the existence of the two monophyletic clades previously described by other authors for guanacos (G) and vicunas (V). Significant levels of mtDNA hybridization were found in the domestic species. Our sequence analyses revealed significant sequence divergence within clade G, and some of the Bolivian llamas grouped with the majority of the southern guanacos. This finding supports the existence of more than the one llama domestication centre in South America previously suggested on the basis of archaeozoological evidence. Additionally, analysis of D-loop sequences revealed two new matrilineal lineages that are distinct from the previously reported G and V clades. The results presented here represent the first report on the population structure and genetic variability of Bolivian camelids and may help to elucidate the complex and dynamic domestication process of SAC populations.