Expression of PER, CRY, and TIM genes for the pathological features of colorectal cancer patients.

As typical clock gene machinery, period (PER1, PER2, and PER3), cryptochrome (CRY1 and CRY2), and timeless (TIM), could control proliferation, cellular metabolism, and many key functions, such as recognition and repair of DNA damage, dysfunction of the circadian clock could result in tumorigenesis of colorectal cancer (CRC). In this study, the expression levels of PER1, PER2, and PER3, as well as CRY1, CRY2, and TIM in the tumor tissue and apparently healthy mucosa from CRC patients were examined and compared via quantitative real-time polymerase chain reaction. Compared with the healthy mucosa from CRC patients, expression levels of PER1, PER2, PER3, and CRY2 in their tumor tissue are much lower, while TIM level was much enhanced. There was no significant difference in the CRY1 expression level. High levels of TIM mRNA were much prevalent in the tumor mucosa with proximal lymph nodes. CRC patients with lower expression of PER1 and PER3 in the tumor tissue showed significantly poorer survival rates. The abnormal expression levels of PER and TIM genes in CRC tissue could be related to the genesis process of the tumor, influencing host-tumor interactions.

Molecular divergence in the timeless and cpr genes among three sympatric cryptic species of the Anopheles triannulatus complex

Anopheles triannulatus s.l. is a malaria vector with a wide geographic distribution, ranging from Argentina-Nicaragua and Trinidad. Here we analysed sequences of two genes, timeless and cpr, to assess the genetic variability and divergence among three sympatric cryptic species of this complex from Salobra, central-western Brazil. The timeless gene sequences did not conclusively differentiate Anopheles halophylus and An. triannulatus species "C". However, a partial separation has been observed between these species and An. triannulatus s.s. Importantly, the analysis of the cpr gene sequences revealed fixed differences, no shared polymorphisms and considerable genetic differentiation among the three species of the An. triannulatus complex. The results confirm that An. triannulatus s.s., An. halophylus and An. triannulatus species C are distinct taxa, with the latter two likely representing a more recent speciation event.