The role of mitochondrial DNA to determine the origin of domestic chicken

Mitochondrial DNA (mtDNA) is has recently lost relevance especially when utilised to study species that are characterised with a history of several migrations. Nonetheless, mtDNA can still represents a useful additional tool in the study of molecular genetic diversity. The reason for the adoption of mtDNA is that it is easy to amplify because it appears in multiple copies in the cells and the mitochondrial gene content is strongly conserved across generations. Thousands of published studies have reached conclusions about population history, patterns of gene flow, genetic structure, and species limits, on the basis of mtDNA sequence variation. MtDNA has been used to study phylo-geographic structure of avian species, and to identify the number of maternal lineages and their geographic origins. Most studies of chicken mtDNA rely on sequences of partial control region but recent researches used the complete mtDNA genome to reconstruct the history of animal domestication. The first genetic study on mtDNA suggests that the Indochinese Red Junglefowl subspecies Gallus gallus gallus is the primary ancestor of the domestic chicken (Gallus gallus domesticus). Other studies showed that at least three subspecies of Gallus gallus were enrolled in the origin of domestic chicken breeds, and that there may be at least two domestication centres: one in Southeast Asia and one in the Indian subcontinent. The authors suggested nine highly divergent clades (named clade A-I) related to geographical distribution in a wide range of domestic chickens and Red Junglefowls across Eurasian regions. Understanding when chickens were transported out of domestication centres and the directions in which they were moved provides information about prehistoric human migration, trade routes and cultural diffusion. MtDNA has been used to infer regions of domestication and to identify the number of maternal lineages and their geographic origins in macroevolution studies.peer-reviewe

morphological and genetic characterisation of pagliarola breed and its genetic relationships with other three indigenous italian sheep breeds

Sheep are an important livestock species in the socio-economic contest around the world. In the past, exotic sheep breeds were utilised in crosses with local breeds in order to improve their production traits. The Pagliarola is an ancient sheep population spread over many areas of the central Italy, mainly in Abruzzo region. The aim of this paper was to identify this breed from other sheep breeds living in the same area trough morphological and genetic characterisation. Fifty-three Pagliarola sheep animals (two flocks) were sampled together with 30 sheep of Appenninica, Gentile di Puglia and Merinizzata Italiana. Biometrical measures and 25 microsatellite markers were studied for the characterisation. In the morphological analysis, the Pagliarola was observed to be well separated from the other breeds and the genomic results confirmed the morphological study. In the molecular approach, a total of 330 alleles were detected. In the neighbour-Net tree, each breed clustered independently and no clear cluster was observed. The expected heterozygosity was the highest in Appenninica (0.78), while Pagliarola had the lowest (0.70). Results of STRUCTURE analyses at K=5 showed Pagliarola breed splitted in two sub-clusters. Both biometric and molecular results allow to consider the residual Pagliarola as an original genotype. Moreover, the variability still remaining in this population can be useful to plan suitable conservation programs

A multivariate morphometric analysis of diagnostic traits in southern Italy and Sicily pubescent oaks

Species identification within the species complex of Q. pubescens is a well-known taxonomic challenge among European botanists. Some of the specific pubescent oak binomials currently accepted in various European floras and checklistswere originally described in Sicily and southern Calabria. As a consequence, several species belonging to the pubescent oaks group (Q. pubescens, Q. amplifolia, Q. congesta, Q. dalechampii, Q. leptobalana and Q. virgiliana) are reported in the taxonomic and phytosociological literature. To verify whether it was possible to associate a diverse set of morphological characters with each of these different taxa, thirteen natural populations of pubescent oak from Sicily and southern Calabria were sampled. A total of 391 trees, 3,887 leaves and 1,047 fruits were collected. Overall, 28 morphological characters of oak leaves and fruits were statistically analysed using univariate and multivariate procedures. The results showed that neither the groups of morphological diversity identified by cluster analysis, nor those obtained by our expert identification through the use of analytical keys, matched with the current taxonomical frameworks as proposed by the most recent floras and checklists. Nearly all of the morphological characters considered displayed a more or less continuous trend of variation, both within and among populations. In the light of these findings it seems unlikely that more than one biological species of pubescent oak occurs in Sicily and southern Calabria

Genetic diversity in four populations of Nguni (Zulu) sheep assessed by microsatellite analysis

Zulu sheep are found mainly in the rural KwaZulu-Natal province and the numbers are declining due to indiscriminate inbreeding. There is thus a need for phenotypic and genetic characterisation as a first phase for planning conservation strategies. Zulu sheep populations sampled were from Makhathini research station (MS) (n=33), University of Zululand (UZ) (n=21), a community at KwaMthethwa (KM) (n=32) and from Msinga (EM) (n=33). One European breed Appen - ninica (AP) was used as out group. Microsatellite analysis using 29 microsatellite loci was used in this study. Among the Zulu sheep, the mean number of alleles per locus was the lowest (3.86) in UZ and the highest (6.24) was realised in EM. The mean values of observed and expected heterozygosity were 0.57 and 0.61, respectively. Neighbour-joining tree showed two main Zulu sheep clusters: the UZ, KM and MS sheep populations clustered together and the second cluster included only representatives from the EM population. The STRUCTURE analysis showed that KM, AP and EM were founded in separate clusters, whereas UZ and MS clustered together. The study demonstrated that there was a common origin of the population from the research stations (MS and UZ populations). It also demonstrated that the EM had a different history for the other three populations. This work suggests that exchange of rams could be useful in reducing inbreeding when considering conservation breeding programmes

Is hypogammaglobulinemia a constant feature in Good's syndrome?

Thymomas are rare tumors, which can be associated to a variety of paraneoplastic syndromes, including a fatal hypogammaglobulinemia, namely Good's Syndrome (GS). Although the combination of thymoma and hypogammaglobulinemia is regarded as sufficient for diagnosis of Good's syndrome, some thymoma patients with a clear clinical picture of immunodeficiency present normal levels of immunoglobulins. We describe the case of a patient, with a 20-year history of thymoma, who underwent several operations and lines of chemotherapy, and suffered from recurrent infections, including one rare skin infection from Pseudoallescheria boydii. The patient constantly presented normal levels of gammaglobulins

Genetic diversity of Cornigliese sheep breed using STR markers

To preserve sheep biodiversity is an important issue as the most productive breeds are becoming dependent on intensive management and breeders are abandoning the traditional breeds. The Cornigliese sheep is a local breed from Parma Apennine. In the last centuries it was crossed with Merino and Bergamasca breeds. The aim of this work is to investigate the genetic variability in the Cornigliese breed using 27 microsatellite markers. A total of 144 individual blood samples were randomly collected from the following breeds: Cornigliese, Bergamasca, Appenninica and Spanish Merino. The Palmera breed was used as out-group. A total of 344 alleles were detected. The average expected heterozygosity ranged from a maximum of 0.77 in Appenninica to a minimum of 0.68 in Bergamasca. In general,Cornigliese showed heterozygosity estimates less than expected. The Reynolds weighted genetic distance among the breeds highlighted a clear cluster, including Cornigliese and Bergamasca. As expected, they appeared in close neighbourhood in the tree because of the historic crossbreeding practices between these two breeds. Results of STRUCTURE analyses show that the four studied breeds were discriminated into separate clusters, even if Cornigliese has some individual related to Bergamasca and Spanish Merino. This work confirmed the historical information about the origin of Cornigliese breed which reports gene flow among these breeds. The genetic parameters show a moderate value of inbreeding in Cornigliese and therefore this breed should be monitored due the low number of individuals that compose it

Reproducibility and Accuracy of the Radiofrequency Echographic Multi-Spectrometry for Femoral Mineral Density Estimation and Discriminative Power of the Femoral Fragility Score in Patients with Primary and Disuse-Related Osteoporosis

We aimed to investigate the reproducibility and accuracy of Radiofrequency Echographic Multi-Spectrometry (REMS) for femoral BMD estimation and the reproducibility and discriminative power of the REMS-derived femoral fragility score. 175 patients with primary and disuse-related osteoporosis were recruited: one femoral Dual-energy X-ray Absorptiometry (DXA) scan and two femoral REMS scans were acquired. No significant test—retest differences were observed for all REMS-derived variables. The diagnostic concordance between DXA and REMS was 63% (Cohen’s kappa = 0.31) in patients with primary osteoporosis and 13% (Cohen’s kappa: −0.04) in patients with disuse-related osteoporosis. No significant difference was observed between REMS and DXA for either femoral neck BMD (mean difference between REMS and DXA: −0.015 g/cm(2)) or total femur BMD (mean difference: −0.004 g/cm(2)) in patients with primary osteoporosis. Significant differences between the two techniques were observed in patients with disuse-related osteoporosis (femoral neck BMD difference: 0.136 g/cm(2); total femur BMD difference: 0.236 g/cm(2)). Statistically significant differences in the fragility score were obtained between the fractured and non-fractured patients for both populations. In conclusion, REMS showed excellent test-retest reproducibility, but the diagnostic concordance between DXA and REMS was between minimal and poor. Further studies are required to improve the REMS—derived estimation of femoral BMD

Uniparental genetic systems: a male and a female perspective in the domestic cattle origin and evolution

Over the last 20 years, the two uniparentally inherited marker systems, namely mitochondrial DNA and Y chromosome have been widely employed to solve questions about origin and prehistorical range expansions, demographic processes, both in humans and domestic animals. The mtDNA and the Y chromosome, with their unique patterns of inheritance, continue to be extremely important source of information. These markers played significant roles in farm animals in the evaluation of the genetic variation within- and among-breed strains and lines and have widely applied in the fields of linkage mapping, paternity tests, prediction of breeding values in genome-assisted selection, analysis of genetic diversity within breeds detection of population admixture, assessment of inbreeding and relationships between breeds, and assignment of individuals to their breed of origin. This approach offers a unique opportunity to save genetic resources and achieving improved productivity. In the past years, significant progress was achieved in reconstructing detailed cattle phylogenies; many studies indicated multiple parental sources and several levels of phylogeographic structuring. More detailed researches are still in progress in order to provide a more comprehensive picture of such extant variability. This paper is focused on reviewing the use of the two uniparental markers as valuable tool for the characterization of cattle genetic diversity. Furthermore, their implications in animal breeding, management and genetic resources conservation are also reported

A microsatellites-based survey on the genetic structure of two Italian local chicken breeds

The biodiversity safeguard is an important goal of poultry production in every developed country. Nowadays, the high chicken meat demand from the world market has been leading to a large spread of strongly producing commercial chicken lines. The creation of these standard types is causing a progressive loss of genetic variability. Ancona and Livorno are two Italian autochthonous chicken breeds which represent a great resource in terms of specific genetic richness. Aim of this study is to investigate the genetic diversity of these breeds as potential valuable genetic variability source. In fact, in spite of their endangered status, these chicken breeds are very appreciated for their ability to adapt themselves to extensive organic rearing systems. Blood samples from 131 individuals were collected and genotyped through a thirty microsatellites-based analysis. All the observed descriptive statistical indexes suggested a heterozygosity deficiency and an inbreeding level (mean observed heterozygosity = 0.46, mean expected heterozygosity = 0.53, Fis in Ancona and Livorno = 0.251 and 0.086). The tree from inter-individual DAS distance using Neighbour-Joining algorithm and the FCA analysis showed a higher internal variability in Livorno than in Ancona. STRUCTURE analysis showed the genetic uniqueness of the breeds and the presence of sub-groups in Ancona originating from a possible genetic isolation. This research could be a suitable starting point to set up improved selection schemes and a potential preliminary genotypic test for all the cocks to be used in the selection

Genetic differentiation between Segugio dell'Appennino and Segugio Maremmano dog breeds assessed by microsatellite markers

The domestic dog (Canis Familiaris) was the first species to be tamed and bred to occupy a variety of functions. The Segugio dell’Appennino and Segugio Maremmano are two Italian breeds used extensively as hunting dogs. Microsatellites and other genetic markers are useful tools in evaluating the within and between breed genetic variation. The aim of this study was to investigate genetic differentiation among the two reeds through the analysis of 21 microsatellite markers. The two populations share the same geographical regions but have been over time selected on different parameters to achieve specific functions. All the analysed microsatellite markers were polymorphic and the average number of alleles per locus was 8.19. The mean FIT index (0.051; P<0.05) highlights that at some point in time, the normal gene flow among the animals was disrupted, giving rise to a heterozygote deficiency in both breeds, and this is confirmed by the mean FST fixation index (0.010; P<0.05) clearly indicating an absence of a significant genetic differentiation between the two breeds. The mean FIS value was significantly different from zero (0.042) (P<0.05) reconfirming the presence of a lack of heterozygosity in the studied samples. The values of observed and expected heterozygosity were similar in the two breeds. AMOVA, PCA and STRUCTURE analysis, all emphasise the lack of significant differences mong the two breeds in terms of genetic differentiation. The presence of a population substructure is probably due to a genetic introgression from different Segugio breeds, that can be confirmed with further studies