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Developmental expression of the Bombyx Antennapedia homologue and homeotic changes in the Nc mutant
Author(s) -
Nagata Toshifumi,
Suzuki Yoshiaki,
Ueno Kohji,
Kokubo Hiroki,
Xu Xin,
Hui Chichung,
Hara Wajiro,
Fukuta Masakazu
Publication year - 1996
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1046/j.1365-2443.1996.d01-260.x
Subject(s) - antennapedia , homeotic gene , biology , bombyx mori , bombyx , homeobox , mutant , prothoracic gland , ultrabithorax , imaginal disc , embryo , genetics , locus (genetics) , microbiology and biotechnology , gene , gene expression , ecdysone
Background : Abundant availability of homeotic mutants in Bombyx mori provides us with clues to study the body plan of the silkworm. Previous studies indicated that the E Ca /E Ca and E N /E N embryos, which reveal drastic morphological changes (Itikawa 1943, 1952) lack the homologue of abd‐A and the homologues of abd‐A and Ubx , respectively (Ueno et al . 1992). It will be interesting to characterize a mutant named Nc , the locus of which was mapped about 1.4 cm apart from the E loci (Itikawa 1944, 1952). Results : In the present study we cloned and identified the Bombyx Antennapedia cDNA from a library of larval middle silk gland. The developmental expression patterns of the Bombyx Antennapedia were analysed in embryos and larval middle silk glands. We found the Bombyx Antennapedia mRNA of the Nc mutant lacks the homeobox region and its downstream region. This defect comes from a corresponding deletion on the Nc chromosome. Development of the Nc/Nc embryos terminates at stage 26, revealing a transformation of the prothoracic legs into antennae, milder changes in the mesothoracic legs, compression between the prothoracic and mesothoracic segments as well as in the gnathocephalon region, and a severe growth suppression of the silk glands. Conclusions : These results give a molecular basis and detailed morphological abnormalities of the Nc mutant known since 1944.