Associations of new rSNPs with eggshell thickness in Rhode Island layers

Six fragments were sequenced of the regulatory and coding regions of the expressed sequence ChEST985k21 (accession number CR523443), which had been shown to affect eggshell thickness. Six sites of single nucleotide polymorphism (SNP) were found, five of them located in the regulatory region and one within the ORF. The binding sites of transcriptional factors for all obtained SNPs were revealed to be present in one allelic variant. Based on this fact they were considered as rSNPs. Genotyping of 46 Rhode Island Red birds with thick (390 +/- 13 mu m) and 45 with thin eggshell (316 +/- 21 mu m) was done. Significant difference in allelic frequency was shown of rSNPs ST2_1, ST3_1, ST3_2, ST3_3. Genotypic classes of rSNPs ST2_1, ST3_1, 5T3_2, ST3_3 and ST6_1 were shown to have significantly different shell thickness. These data could probably provide a tool for marker-assisted selection for optimization of egg shell thickness in Rhode Island layers.