[Cytogenetics and application in domesticated silkworm Bombyx mori]

Abstract

Chromosome identification and karyotype analyses of Bombyx mori (Lepidoptera) have long been hampered by the high number and the absence of suitable markers, such as centromeric position and chromosome bands. Recently, the cytological map has been constructed using comparative genomic hybridization-genomic in situ hybridization and BAC-based fluorescence in situ hybridization. Dense cytogenetic maps are being constructed by integrating cytological map with molecular linkage maps. Molecular and cytogenetics will help us to reveal the structure and function of chromosome of Bombyx mori, the W chromosome is composed largely of dense nested retrotransposons, and telomeres are consist of the TTAGG motifs and two type of telomere-specific non-LTR retrotransposons (TRAS1 and SART1), the TRAS1 and SART1 with abundant transcription activity may be involved in the stabilization of chromosomal ends.