E. Cauvin

Population genetic structure of Alpine chamois (Rupicapra r. rupicapra) in the Italian Alps

Analysis of the genetic diversity of the Alpine chamois in Italy was conducted using a pool of 26 microsatellite loci. A total of 209 animals were analyzed, representing six geographical populations from different location of the Southern slope of the Alps. Clear genetic differences have emerged between the sampled chamois groups. Some were consistent with an isolation-by-distance model. However, in parallel, other mechanisms intervened in areas that, in addition to being peripheral to the main alpine ridge, had suffered from recent bottlenecks. In such areas, genetic drift and a low rate of gene flow are likely explanations for the current genetic structure.

MUC1 gene polymorphism in three Nelore lines selected for growth and its association with growth and carcass traits

The objective of this study was to describe the VNTR polymorphism of the mucin 1 gene (MUC1) in three Nelore lines selected for yearling weight to determine whether allele and genotype frequencies of this polymorphism were affected by selection for growth. In addition, the effects of the polymorphism on growth and carcass traits were evaluated. Birth, weaning and yearling weights, rump height, Longissimus muscle area, backfat thickness, and rump fat thickness, were analyzed. A total of 295 Nelore heifers from the Beef Cattle Research Center, Instituto de Zootecnia de Sertãozinho, were used, including 41 of the control line, 102 of the selection line and 152 of the traditional. The selection and traditional lines comprise animals selected for higher yearling weight, whereas control line animals are selected for yearling weight close to the average. Five alleles were identified, with allele 1 being the most frequent in the three lines, especially in the lines selected for higher means for yearling weight. Heterozygosity was significantly higher in the control line. Association analyses showed significant effects of allele 1 on birth weight and weaning weight while the allele 3 exert significant effects on yearling weight and back fat thickness. Despite these findings, application of this marker to marker-assisted selection requires more consistent results based on the genotyping of a larger number of animals in order to increase the accuracy of the statistical analyses.

Polymorphism of Genetic variability of gene in sheep

Riassunto Il polimorfismo del gene MUC1 nella pecora. Il gene MUC1 esprime una mucina della membrana dei globuli di grasso del latte e contiene una regione ripetitiva ipervariabile. La sequenza di MUC1 è nota nel bovino e nella capra ma non nella pecora. Un’analisi preliminare della regione ripetitiva, eseguita mediante PCR su 23 soggetti di razza Tacola utilizzando una coppia di oligonucleotidi disegnati sulla sequenza di capra, ha evidenziato il polimorfismo di lunghezza già noto per MUC1 di uomo, bovino e capra. L’analisi della sequenza di un frammento ha dimostrato l’esistenza di una regione ripetitiva formata da un’unità di 60 bp ripetuta in successione, caratteristica in comune con il gene MUC1 delle altre specie. I risultati ottenuti sono il primo contributo alla conoscenza di MUC1 di pecora e consentono di avviare indagini sul suo polimorfismo nelle razze ovine.