Silk gland-specific tRNA(Ala) genes are tightly clustered in the silkworm genome.
To understand the basis for tissue-specific production and accumulation of alanine tRNA in silkworms, we have examined the organization of the genes that code for silk gland-specific and constitutive alanine tRNAs. We have found that all of the silk gland-specific tRNA(Ala) genes (approximately 20) appear to be tightly clustered at a single locus in the Bombyx genome. These genes are arranged in tandem at intervals of approximately 150 base pairs. In contrast to the arrangement of the silk gland-specific tRNA(Ala) genes, most of the 20 to 30 constitutive tRNA(Ala) genes are dispersed in the genome. Silk gland-specific tRNA(Ala) genes are not amplified or grossly rearranged in the silk gland. Thus it is likely that differential transcription, rather than changes in gene number or structure, accounts for the tissue-specific accumulation of tRNA(Ala).
Underwood
D C
DC
Institute of Molecular Biology, University of Oregon, Eugene 97403.
Knickerbocker
H
H
Gardner
G
G
Condliffe
D P
DP
Sprague
K U
KU
D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000235:genetics*; D005796:Genes; D008969:Molecular Sequence Data; D005810:Multigene Family; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes; D012344:RNA, Transfer, Ala / Q000235:genetics*; D012345:RNA, Transfer, Amino Acid-Specific / Q000235:genetics*; D015183:Restriction Mapping
D015345:Oligonucleotide Probes; D012344:RNA, Transfer, Ala; D012345:RNA, Transfer, Amino Acid-Specific