title: Eimeria tenella: cloning and characterization of telomerase reverse transcriptase gene.
abstract: Telomerase is essential for maintaining telomere length and chromosome stability in most eukaryotic organisms. The telomerase ribonucleoprotein complex consists of two essential components, the intrinsic telomerase RNA and the catalytic telomerase reverse transcriptase protein. Here we describe the cloning, sequencing and characterization of the telomerase reverse transcriptase catalytic subunit from the apicomplexan protozoon Eimeria tenella. The amino acid sequence predicted from it has all the signature motifs of the TERT family members. The E. tenella TERT cDNA contains an open reading frame encoding a protein with 1497 amino acids predicted size of 172kDa and isoelectric point of 9.344. It contains the conserved reverse transcriptase motifs 1, 2, A, B, C, D and E as well as the TERT-specific T motif and the N-terminal conserved motifs GQ, CP and QFP. RT-PCR analysis indicated that E. tenella TERT mRNA expressed in sporozoites and merozoites phase while not in unsporulated oocysts. At the same time, the result of TRAP assay indicated that marked telomerase activity were detected in sporozoites and merozoites. In contrast, telomerase activity was not detected in unsporulated oocysts.
authors.affiliation: College of Animal Science and Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
authors.forename: Guilian
authors.initials: G
authors.lastname: Yang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Li
authors.forename: Xichen
authors.initials: X
authors.lastname: Zhang
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhao
authors.forename: Pengtao
authors.initials: P
authors.lastname: Gong
authors.forename: Baoyan
authors.initials: B
authors.lastname: Ren
authors.forename: Guocai
authors.initials: G
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D003001:Cloning, Molecular; D003048:Coccidiosis / Q000469:parasitology / Q000662:veterinary; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification; D016054:DNA, Protozoan / Q000737:chemistry / Q000302:isolation & purification; D016786:Eimeria tenella / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D008969:Molecular Sequence Data; D010802:Phylogeny; D011201:Poultry Diseases / Q000469:parasitology; D016053:RNA, Protozoan / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment / Q000662:veterinary; D013047:Specific Pathogen-Free Organisms; D019098:Telomerase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D016054:DNA, Protozoan; D016053:RNA, Protozoan; D019098:Telomerase