Oral communication, CS7 / C24

Official XXIst International Pigment Cell Conference website - 21-24 Sept 2011, Bordeaux - France | updated: September 04 2011

Gene duplication linked to Fm locus is closely correlated to hyperpigmentation of internal organs in Silky chicken

SPEAKER A. Shinomiya #whois submiter ?
AUTHOR(s) A. Shinomiya, K. Kinoshita, M. Mizutani, T. Namikawa, Y. Matsuda, Y. Kayashima, T. Akiyama

Silky chicken displays heavy melanization in their internal organs and the trait is designated as Fibromelanosis (Fm). In our previous analysis, the segregation rate of Fm and fm (wild type) in F2 progeny between Silky (Fm) and Black Minorca or Fayoumi (fm) was closely to 3:1, showing that Fm was controlled by a single dominant gene. The purpose of this study is to map the gene responsible for Fm. We performed genetic linkage analysis using backcross progeny (BC) from crossing between Black Minorca and (Silky X Black Minorca) F1, and found one microsatellite marker linked to Fm (93%). We developed new sequence tagged site markers around the microsatellite marker using the information of the chicken draft genome sequence, and mapped the Fm locus in the extent of 1.46 Mb on the chicken chromosome 20 by genotyping of the BC progeny (n=87). Furthermore, we found a DNA segment, of which copy number in Silky was twice higher than that in Black Minorca, within the Fm region by quantitative real-time PCR assay, and linkage analysis of the gene duplication and Fm confirmed that the duplicated copy was also located in the Fm region. Further analyses demonstrated that the duplicated segment was the extent of approximately 130 kb and that the gene duplication was not observed in other fm lines (Fayoumi and Red jungle fowl). In the 130 kb-region, five genes were located and the expression levels of four out of the five genes in Silky were higher than those in Black Minorca. Present results demonstrate close correlation between the Fm phenotype and the gene duplication. We will discuss the mechanism of hyperpigmentation in Silky chicken.



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Université de Bordeaux 2 & Conseil Régional Aquitaine