title: Three EST-SSR markers associated with QTL for the growth of the clam Meretrix meretrix revealed by selective genotyping.
abstract: The clam Meretrix meretrix is a member of widely cultured, commercially important clams. A marker-trait association analysis was performed using expressed sequence tag (EST) simple sequence repeat (SSR) markers for marker-assisted selection in M. meretrix. Three markers, MM1272, MM2034, and MM7721, were found to be significantly associated with quantitative trait loci (QTLs) controlling shell length (P < 0.0001) in clams of a fast-growing population (JSF) and a control population (JSC). The 144-bp allele of MM1272, the 154-bp allele of MM2034, and the 152- and 165-bp alleles of MM7721 showed a significantly higher frequency in the JSF population (17.65, 36.41, 28.67, and 29.33 %) than in the JSC population (4.65, 8.33, 3.47, and 5.56 %). The three markers showed lower values for the number of alleles and observed heterozygosity as well as a higher proportion of homozygotes in JSF than in JSC population. The three markers have been further confirmed in the high and low tails of another population (09G₃SPSB); similarly, lower values for the number of alleles and observed heterozygosity as well as a higher proportion of homozygotes were found in 09G₃SPSB(H). The putative functions of the three gene fragments containing MM1272, MM2034, and MM7721 also suggested that the three SSR-containing genes might be involved in growth of M. meretrix. All the results suggest that the three EST-SSR markers associated with growth QTLs would be useful for marker-assisted selection in M. meretrix breeding.
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Lu
authors.forename: Hongxia
authors.initials: H
authors.lastname: Wang
authors.forename: Baozhong
authors.initials: B
authors.lastname: Liu
authors.forename: Jianhai
authors.initials: J
authors.lastname: Xiang
mesh_terms: D060105:Animal Shells / Q000254:growth & development*; D000818:Animals; D017756:Aquaculture / Q000379:methods; D049872:Bivalvia / Q000235:genetics* / Q000254:growth & development*; D001947:Breeding / Q000379:methods; D002681:China; D002874:Chromosome Mapping; D017931:DNA Primers / Q000235:genetics; D020224:Expressed Sequence Tags; D005787:Gene Frequency; D005819:Genetic Markers / Q000235:genetics; D005838:Genotype; D018895:Microsatellite Repeats / Q000235:genetics*; D040641:Quantitative Trait Loci / Q000235:genetics*; D012641:Selection, Genetic
chemical_list: D017931:DNA Primers; D005819:Genetic Markers