Identification of a novel Brugia pahangi beta-tubulin gene (beta 2) and a 22-nucleotide spliced leader sequence on beta 1-tubulin mRNA.
We have examined the expression of beta-tubulin genes in the parasitic nematode, Brugia pahangi. A genomic library was constructed and screened by hybridization with a Haemonchus contortus beta-tubulin cDNA fragment which recognizes several B. pahangi beta-tubulin sequences, including sequences which correspond to the previously characterized beta 1-tubulin gene. The B. pahangi beta 2-tubulin gene was isolated by selecting clones which hybridize to the H. contortus beta-tubulin gene but which do not hybridize to the beta 1-tubulin gene. A partial sequence of the beta 2-tubulin gene confirms that it codes for a distinct beta-tubulin. Southern hybridization analyses show that the beta 2-tubulin sequence exists as a single copy gene within the B. pahangi genome. Expression of the beta 2-tubulin gene is developmentally regulated and the message is found predominantly in adult male worms, whereas the beta 1-tubulin gene is expressed in microfilariae and approximately equal levels of the transcript are found in male and female adult worms. During mRNA maturation the beta 1-tubulin mRNA of microfilariae and adult worms acquires a trans-spliced leader identical to the SL1 of Caenorhabditis elegans.
Guénette
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S
Institute of Parasitology, McGill University, Ste-Anne de Bellevue, Quebec, Canada.
Prichard
R K
RK
Matlashewski
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G
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002009:Brugia / Q000235:genetics* / Q000254:growth & development; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation; D015698:Genomic Library; D005849:Gerbillinae; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism*; D012727:Sex Characteristics; D014404:Tubulin / Q000235:genetics*
D012333:RNA, Messenger; D014404:Tubulin; D004247:DNA