Chunyan Bai

A base substitution in the donor site of intron 12 of KIT gene is responsible for the dominant white coat colour of blue fox (Alopex lagopus).

The dominant white coat colour of farmed blue fox is inherited as a monogenic autosomal dominant trait and is suggested to be embryonic lethal in the homozygous state. In this study, the transcripts of KIT were identified by RT-PCR for a dominant white fox and a normal blue fox. Sequence analysis showed that the KIT transcript in normal blue fox contained the full-length coding sequence of 2919 bp (GenBank Acc. No KF530833), but in the dominant white individual, a truncated isoform lacking the entire exon 12 specifically co-expressed with the normal transcript. Genomic DNA sequencing revealed that a single nucleotide polymorphism (c.1867+1G>T) in intron 12 appeared only in the dominant white individuals and a 1-bp ins/del polymorphism in the same intron showed in individuals representing two different coat colours. Genotyping results of the SNP with PCR-RFLP in 185 individuals showed all 90 normal blue foxes were homozygous for the G allele, and all dominant white individuals were heterozygous. Due to the truncated protein with a deletion of 35 amino acids and an amino acid replacement (p.Pro623Ala) located in the conserved ATP binding domain, we propose that the mutant receptor had absent tyrosine kinase activity. These findings reveal that the base substitution at the first nucleotide of intron 12 of KIT gene, resulting in skipping of exon 12, is a causative mutation responsible for the dominant white phenotype of blue fox.

Complete mitochondrial genome of the Spotted dove (Streptopelia chinensis).

Abstract The Spotted dove (Streptopelia chinensis) is a member of the bird family Columbidae. In this study, we report the complete mitochondrial genome of this species. The mitochondrial genome of Spotted dove is a circular molecule of 16,966 bp in size and contains 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and one control region. The total base composition is 30.1% for A, 32.1% for C, 13.9% for G, and 23.9% for T. These data will be useful for the phylogenetic and population diversity analyses of birds, especially Columbidae species.

miR-375 down-regulation of the rearranged L-myc fusion and hypoxia-induced gene domain protein 1A genes and effects on Sertoli cell proliferation

Objective This study aimed to screen and identify the target genes of miR-375 in pig Sertoli (ST) cells and to elucidate the effect of miR-375 on the proliferation of ST cells. Methods In this study, bioinformatics software was used to predict and verify miR-375 target genes. Quantitative polymerase chain reaction (PCR) was used to detect the relationship between miR-375 and its target genes in ST cells. Enzyme-linked immunosorbent assay (ELISA) of rearranged L-myc fusion (RLF) and hypoxia-induced gene domain protein 1A (HIGD1A) was performed on porcine ST cells, which were transfected with a miR-375 mimics and inhibitor to verify the results. Dual luciferase reporter gene assays were performed to assess the interactions among miR-375, RLF, and HIGD1A. The effect of miR-375 on the proliferation of ST cells was analyzed by CellTiter 96 AQueous One Solution Cell Proliferation Assay (MTS). Results Five possible target genes of miR-375, including RLF, HIGD1A, colorectal cancer associated 2, POU class 3 homeobox 1, and WW domain binding protein 1 like, were found. The results of quantitative PCR suggested that mRNA expression of RLF and HIGD1A had a negative correlation with miR-375, indicating that RLF and HIGD1A are likely the target genes of miR-375. The ELISA results revealed that RLF and HIGD1A were negatively correlated with the miR-375 protein level. The luminescence results for the miR-375 group co-transfected with wild-type RLF and HIGD1A vector were significantly lower than those of the miR-375 group co-transfected with the blank vector or mutant RLF and HIGD1A vectors. The present findings suggest that RLF and HIGD1A are target genes of miR-375 and that miR-375 inhibits ST cell proliferation according to MTS analysis. Conclusion It was speculated that miR-375 affects cell proliferation through its target genes, which play an important role in the development of testicular tissue.

The complete sequence of the mitochondrial genome of Arctic fox (Alopex lagopus)

Abstract In the present study, the complete mitochondrial genome sequence of Arctic fox (Alopex lagopus) was determined for the first time. It has a total length of 16,656 bp, and contains 13 protein-coding genes, 22 tRNA genes, 2 ribosome RNA genes and 1 control region. The nucleotide composition is 31.3% for A, 26.2% for C, 14.8% for G and 27.7% for T, respectively. The D-loop region located between tRNAPro and tRNAPhe contains a (ACACGTACACGCAT)18 tandem repeat array. The data will be useful for the investigation of the genetic structure and diversity in the natural and farmed population of Arctic foxes.

Identification and characterization of the cDNA sequence encoding amelogenin in rabbit (Oryctolagus cuniculus).

Amelogenins, the most abundant proteins in tooth enamel extracellular matrix (ECM), are essential for tooth amelogenesis. The nucleotide sequence of amelogenin gene (AMEL) for rabbit, as an important member of mammals and good continuously growing incisor model, is important for comparative and evolutional study. Previous studies about rabbit amelogenin proteins got no consensus yet even as to their existence or size. In this study, with combined usage of in silico and molecular cloning technologies, we identified sequences of two transcripts of rabbit amelogenin, resulting from the alternative splicing of the 45-bp exon 4. The coding regions of the two transcripts are of 567- and 522-bp, encoding 188 and 173 amino acids including a 17-residue signal peptide, respectively. Sequence analysis revealed that rabbit amelogenin features in extremely high GC-content in nucleotide sequence and Alanine content in protein sequence. Detailed comparison of amino acid sequence with other mammals showed that the rabbit amelogenin protein is conserved in the sites and regions important for protein functions. Overall, our results uncovered the mysteries about rabbit amelogenin and revealed its sequence peculiarities.

Complete mitochondrial genome of the Common redpoll (Carduelis flammea)

Abstract The Common redpoll (Carduelis flammea) is one species of family Fringillidae. In the present study, we determined the complete mitochondrial DNA sequences of this species. The mitochondrial genome of Common redpoll is a circular molecule of 16 820 bp in size and contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 1 control region. The total base composition is 31.35% for C, 14.14% for G, 30.57% for A and 23.94% for T, respectively. The phylogenetic tree of Common redpoll and 12 other closely related Fringillidae species was built. These data will be useful for studying the genetic diversity within the species of Common redpoll and phylogenetic relationships among different Fringillidae species.

Sex identification of dog by PCR based on the differences in the AMELX and AMELY genes

Cloning of canine AMELY: Genomic DNA was extracted from peripheral blood of 128 dogs belonging to 12 breeds, provided by Animal Hospital of Jilin University. PCR amplification with primers (DAME-F: 5′-GGCACCCTGGTT ATATCAACT-3′; DAME-R: 5′-CCACTTCYTCCYGCTTGGTC TT-3′, Y = C/T), designed according to human, bovine and swine AMELY sequences, yielded one band in the female, whereas two bands were present in the male (Fig. 1a). Sequencing results showed that the obtained AMELY fragment was 1947 bp in length (GenBank accession no. KC763835) with multiple nucleotide indels, compared with the corresponding AMELX sequence of 2345 bp (GenBank accession no. NC_006621).