The silk moth Bombyx mori U1 and U2 snRNA variants are differentially expressed

Gene. 2005 Jun 6;352:127-36. doi: 10.1016/j.gene.2005.02.013.


Five U1 and eight U2 isoforms of the silk moth Bombyx mori exhibiting internal nucleotide differences have been previously identified and characterized in various tissues and developmental stages. In this investigation, it is demonstrated that the levels of some snRNA variants differ in egg and silk gland tissue and change during development. Qualitative and quantitative differences in the U1 and U2 variant populations were observed at three developmental points (early, middle and late) of the silk gland (SG) during the fifth instar larval stage of the silk moth. Statistical analyses of the various isoform populations across the fifth instar larval and egg stages show significant differences for some of the U1 and U2 variants. The representation of variant sequences in expressed U1 and U2 sequences (RT-PCR libraries) and in a whole-genome shotgun (WGS) assembly database was confirmed. In addition, conserved elements in the promoter 5'-flanking region of the U1 and U2 variants were identified in the WGS.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Bombyx / genetics*
  • Bombyx / growth & development
  • Chi-Square Distribution
  • DNA / chemistry
  • DNA / genetics
  • DNA, Complementary / chemistry
  • DNA, Complementary / genetics
  • Databases, Nucleic Acid
  • Gene Expression Profiling*
  • Gene Expression Regulation, Developmental
  • Gene Library
  • Genetic Variation
  • Genome
  • Molecular Sequence Data
  • Promoter Regions, Genetic / genetics
  • RNA, Small Nuclear / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Nucleic Acid


  • DNA, Complementary
  • RNA, Small Nuclear
  • U1 small nuclear RNA
  • U2 small nuclear RNA
  • DNA