abstract
- In eukaryotes, the timeless (TIM) gene plays a fundamental role in the control of the circadian clock by regulating several biochemical, physiological, and behavioral processes. RT-PCR was used to amplify TIM mRNA from larval southern house mosquito, Culex quinquefasciatus Say, from three locations in the State of Nuevo Leon in northeastern Mexico. The 3062 bp TIM cDNA was assembled from three overlapping PCRs that were cloned and sequenced. DNA sequence analysis used amplified cDNA fragments to complete coding the DNA sequence (2991 bp). Tim ORF consisting of 996 codons was shorter than the orthologous genes from other mosquito species. A series of deletions in the core sequence of TIM were detected. No other amplification products were visualized, and thus, the possibility of alternative spliced mRNA species was discarded. Because TIM is a widely conserved gene in eukaryotes, and maintaining colonies of Cx. quinquefasciatus is easy, determining the sequence of the TIM gene in the mosquito provides the possibility of its use as a model for circadian clock experimentation.