Search results for "population structure"
showing 10 items of 67 documents
Application of molecular markers to investigate genetic diversity in Sicilian livestock
2014
La diversità genetica delle specie e razze di interesse zootecnico, rappresenta un’importante risorsa in tutti i sistemi di allevamento . Per lo studio della diversità genetica, nel corso dei decenni sono stati sviluppati diversi metodi che si basano su informazioni del pedigree o su dati molecolari (microsatelliti e SNPs, Single Nucleotide Polymorphisms). Con l’aumento della disponibilità di marcatori molecolari per la maggior parte delle specie di interesse zootecnico, e con lo sviluppo di sofisticate tecniche analitiche, sta crescendo la capacità di caratterizzare la variabilità genetica delle razze. Inoltre, ad oggi, poche sono le informazioni sulla diversità genetica delle razze e dell…
A genome-wide perspective on the population structure of Italian cattle breeds
2018
Despite the growing diffusion of cosmopolite specialized breeds, several autochthonous cattle breeds and populations are still bred in Italy. The aim of this study was to provide a high-resolution picture of the genome-wide diversity and population structure of Italian local cattle breeds using medium-density genome-wide SNP markers. After data editing, the dataset included 800 samples from 32 breeds that were genotyped for 31 013 SNPs. For several breeds we observed a low level of polymorphism and genetic diversity, that together with the small effective population sizes confirmed threat of extinction. According to the runs of homozygosity analysis, evidence of recent inbreeding was strong…
First Data on the Mysid Community in the “Stagnone di Marsala” (Western Sicily)
2001
First data on the spatial and temporal distribution of the mysid community in the “Stagnone di Marsala” (western Sicily) from January to December 1996 are reported. The assemblage consists mainly of five species which are common in the Mediterranean Sea: Diamysis bahirensis (55.2%), Siriella armata (18.6%), S. clausii (15.8%), Mysidopsis gibbosa (9.8%) and Mesopodospis slabberi (0.6%). Population structure is described for each species and the reproductive period inferred. A sharp increase in abundance occurred in the spring, while the minima occurred during autumn-winter. The D. bahirensis dominated from March to October and S. clausii in the winter. A large difference, which was mainly qu…
Genetic diversity and population structure of Sicilian sheep breeds using microsatellite markers
2012
Abstract Genetic diversity studies in domestic animals aim at evaluating genetic variation within and across breeds mainly for conservation purposes. In Sicily, dairy sheep production represents an important resource for hilly and mountain areas economy. Their milk is used for the production of traditional raw milk cheeses, sometimes protected designation of origin (PDO) cheeses. In some cases, the quality of these products is linked to a specific breed, i.e. mono-breed labelled cheeses and it is therefore important to be able to distinguish the milk of a breed from that of others, in order to guarantee both the consumer and the breed itself. In order to investigate the genetic structure an…
Growth and reproduction data of Plesionika narval (Decapoda, Caridea, Pandalidae) off the Island of Ustica (southern Tyrrhenian Sea)
2011
[We here report some data on the biology and population structure of Plesionika narval (Fabricius, 1787) captured along the coast of the island of Ustica in the southern Tyrrhenian Sea. Specimens were collected monthly from January to October 2000 using commercial traps at depths ranging from 15 to 100 metres. The carapace length (CL) of females ranged between 7.0 and 26.0 mm, and between 7.0 and 17.0 mm for males. Three modes were identified in the cumulative frequency distribution for females but only two for males. In females, the third modal value was observed only at the deeper sample sites. The Von Bertalanffy growth parameters and performance index p were K = 0.65 y–1, CL∞ = 27.4 mm …
BOVITA: a first overview on genome-wide genetic diversity of Italian autochthonous cattle breeds
2017
On the origin and diversification of Podolian cattle breeds: testing scenarios of European colonization using genome-wide SNP data
2021
AbstractBackgroundDuring the Neolithic expansion, cattle accompanied humans and spread from their domestication centres to colonize the ancient world. In addition, European cattle occasionally intermingled with both indicine cattle and local aurochs resulting in an exclusive pattern of genetic diversity. Among the most ancient European cattle are breeds that belong to the so-called Podolian trunk, the history of which is still not well established. Here, we used genome-wide single nucleotide polymorphism (SNP) data on 806 individuals belonging to 36 breeds to reconstruct the origin and diversification of Podolian cattle and to provide a reliable scenario of the European colonization, throug…
Adaptation to a seasonally varying environment: a strong latitudinal cline in reproductive diapause combined with high gene flow in Drosophila montana
2011
Adaptation to seasonal changes in the northern hemisphere includes an ability to predict the forthcoming cold season from gradual changes in environmental cues early enough to prepare for the harsh winter conditions. The magnitude and speed of changes in these cues vary between the latitudes, which induces strong selection pressures for local adaptation. We studied adaptation to seasonal changes in Drosophila montana, a northern maltfly, by defining the photoperiodic conditions leading to adult reproductive diapause along a latitudinal cline in Finland and by measuring genetic differentiation and the amount of gene flow between the sampling sites with microsatellites. Our data revealed a cl…
Demographic characterization and genetic variability of the Girgentana goat breed by the analysis of genealogical data
2004
The aim of this paper is to present an overview of the actual Sicilian Girgentana population structure by the analysis ofgenealogical data. Statistics show that in 1983 the population consisted of 30,000 Girgentana goats; ten years lateralmost 98% of the entire Girgentana population disappeared. The remaining population consists of 461 individuals (134males and 327 females), with 368 living animals. The effective population size is 380 individuals. The inbreeding rate pergeneration was equal to 0.13%. The average estimated inbreeding level within the living male population was equal to0.8% (0-15%); and the average inbreeding level within the living female population was equal to 0.7% (0-31%…
Anthropological investigation of a Kurdish village population from south-eastern Turkey. II. Internal differentiation of morphological features
1988
A small scale village society from southern Turkey has been investigated by demographic, social and anthropological criteria. An internal differentiation of the population on the basis of demographic and social data could be verified for morphological features, too. This is shown clearly by a differentiation of the population into two family complexes. The consequences for the interpretation of metrical random sample surveys in typological investigations are discussed.