ABSTRACT
Karyopherins, including alpha and beta types, are transport proteins in the eukaryotic cell that carry cargoes across nuclear pore complexes into or out of the nucleus. In this study, full open reading frames of one beta and three alpha types of karyopherin were cloned from cDNA of the domestic silkworm (Bombyx mori). The one beta and three alpha types' open reading frames were 2661, 1563, 1515, and 1551 base pairs long, respectively, and coded 886, 520, 504, and 516 amino acids, respectively. The alphas all had one importin-beta-binding (IBB) domain, and eight, four, or seven armadillo/beta-catenin-like repeats. The beta had 19 HEAT repeat domains, which constructed one importin-beta-N-terminal domain and one IBB domain. The recombinant proteins were expressed in Escherichia coli cells. The molecular weight of the beta type was approximately 100 kDa, and the alphas weighed approximately 60 kDa. Phylogenic tree construction revealed that the alphas could be classified into three known karyopherin-alpha subfamilies. We detected mRNA of the four karyopherins in normal 3rd day of 5th instar larvae, and in larvae injected with Gram-positive bacteria, Gram-negative bacteria, viruses, and fungi using real-time fluorescence quantitative reverse transcriptase-polymerase chain reaction, and found that the four karyopherins were widely distributed, but their expression levels were related to tissues type, the microbe injected, and the time point.
Subject(s)
Bombyx/genetics , Bombyx/immunology , Gene Expression , Immunity , Karyopherins/genetics , Amino Acid Sequence , Animals , Base Sequence , Bombyx/classification , Cloning, Molecular , Karyopherins/chemistry , Karyopherins/metabolism , Molecular Sequence Data , Open Reading Frames , Organ Specificity/genetics , Phylogeny , RNA, Messenger/genetics , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Alignment , Sequence Analysis, DNAABSTRACT
In the silkworm, Bombyx mori, normal markings are mainly controlled by the +P gene, which is located on the second chromosome. Due to a lack of crossing over in females, reciprocal backcrossed F1 (BC1) progenies were used for linkage analysis and mapping of the +P gene based on an SSR linkage map using silkworm strains P50 and H9, which are normal marking and sex-limited marking, respectively. The +P gene was found to be linked to 3 SSR markers. Using a reciprocal BC1M cross, we constructed a linkage map of 22.5 cM, with +P mapped at 11.3 cM and the nearest SSR marker S0206 at a distance of 3.0 cM. Based on a fine genome map of domesticated silkworms, Kaikoblast analysis showed that the physical distance between the nearest markers (containing the +P gene) is 995 kb. Further analysis showed that BGIBMGA009689, BGIBMGA009688, and BGIBMGA009687 are closer to +P, and that BGIBMGA009689 is closest to +P, with a physical distance of 19.1 kb.