Insulin-like growth factor 1 receptor (IGF1R) is a cell surface receptor, belonging to the tyrosine kinase receptor superfamily. IGF1R plays a role not only in normal cell development but also in malignant transformation, which has become a candidate therapeutic target for the treatment of human cancer. This study aimed to explore insertions and deletions (indels) in IGF1R gene and investigate their association with growth traits in four Chinese cattle breeds (Xianan cattle, Jinnan cattle, Qinchuan cattle and Nanyang cattle). The current paper identified a 28-bp indel by polymerase chain reaction within IGF1R gene. The analysis showed that there was a significant correlation between the locus and the hucklebone width of Nanyang cattle in four periods, in which it was highly correlated at 6, 12 and 18 months. At the age of 6 months, it was also significantly correlated with body height, body weight and body length. Association analysis showed that the locus in Jinnan cattle was extremely significantly correlated with body slanting length and body weight, and significantly correlated with chest circumference. There was no significant correlation between this locus and growth traits of Xianan cattle and Qinchuan cattle. The detected indel in the IGF1R gene was significantly associated with growth traits in Jinnan and Nanyang cattle, and could be used as a molecular marker for growth trait selection.

Alternative oxidase (AOX) has been proposed as a promising functional marker candidate for multiple plant stress behaviour. The present paper describes natural polymorphism in AOX2b of Daucus carota L. (DcAOX2b). Exon-primed intron crossing-PCR (EPIC-PCR) revealed length variation (intron length polymorphisms, ILPs) in intron 1. Six fragment patterns were identified in 40 genotypes. However, no more than two fragments were found per genotype, suggesting the presence of two alleles. The ILPs were able to discriminate between single plant genotypes in cv. Rotin and to distinguish individual wild carrot plants. The repetitive pattern of intron 1 length variation allows the grouping of genotypes for functional analysis in future studies. Sequence analysis in intron 1 of polymorphic but also of obviously identical PCR-fragments revealed underlying high levels of sequence polymorphisms between alleles and genotypes. Variation was due to repetitive insertion/deletion (InDel) events and single-nucleotide polymorphisms (SNPs). The results suggest that high AOX2b gene diversity in D. carota may be a source of functional markers for agronomic traits related to environmental stress responses.