Many insects gain directional information from the polarization pattern of the sky. Polarization vision is mediated by the specialized ommatidia of the dorsal rim area of the compound eye, which contains highly polarization-sensitive photoreceptors. In crickets Gryllus campestris, polarized light information conveyed by the dorsal rim ommatidia was found to be processed by polarization-opponent...

During nuclear DNA replication, proofreading-deficient DNA polymerase a (Pol a) initiates Okazaki fragment synthesis with lower fidelity than bulk replication by proofreading-proficient Pol d or Pol e. Here, we provide evidence that the exonuclease activity of mammalian flap endonuclease (FEN1) excises Pol a replication errors in a MutSa-dependent, MutLa-independent mismatch repair process we c...

Studies using Escherichia coli DNA polymerase (Pol) III as the prototype for bacterial DNA replication have suggested that--in contrast to eukaryotes--one replicase performs all of the main functions at the replication fork. However, recent studies have revealed that replication in other bacteria requires two forms of Pol III, one of which seems to extend RNA primers by only a few nucleotides b...

BACKGROUND Eukaryotic DNA polymerase β (pol β), the polymerase thought to be responsible for DNA repair synthesis, has been extensively characterized in rats and humans. However, pol β has not been purified or enzymatically characterized from the model fish species Danio rerio (zebrafish). We used the in vitro/in vivo dual expression system plasmid, pIVEX, to express Danio rerio pol β (Danio po...

This article has been published as a correction for an error in the manuscript of Pavlov et al BMC Biology 2004, 2:11. This article has been published as a correction for [1]. The legend for figure 2 in the original article states, "(C) Plot of time-course of DNA synthesis and dTMP turnover by wild-type Pol e. Open circles connected by solid line represent dTMP retained into DNA; open rectangle...

This report discovers a role of Escherichia coli RecA, the cellular recombinase, in directing the action of several DNA polymerases at the replication fork. Bulk chromosome replication is performed by DNA polymerase (Pol) III. However, E. coli contains translesion synthesis (TLS) Pols II, IV, and V that also function with the helicase, primase, and sliding clamp in the replisome. Surprisingly, ...

the present paper is about an inscription from the parthian era which has been found in the town of sar-e pol-e zohab in the province of kirmanshah. this parthian bas-relief is about two people on the two sides of the bas-relief inscription. the investigation on the right-handside, due to erosion is not quite readable, but the left-handside inscription had been formerly read and believed to be ...

Endogenous metabolism, environmental exposure, and treatment with some chemotherapeutic agents can all give rise to DNA alkylation, which can occur on the phosphate backbone as well as the ring nitrogen or exocyclic nitrogen and oxygen atoms of nucleobases. Previous studies showed that the minor-groove O(2)-alkylated thymidine (O(2)-alkyldT) lesions are poorly repaired and persist in mammalian ...

Spontaneous mutations arise not only in exponentially growing bacteria but also in non-dividing or slowly dividing stationary-phase cells. In the latter case mutations are called adaptive or stationary-phase mutations. High spontaneous mutability has been observed in temperature sensitive Escherichia coli dnaQ49 strain deficient in 3'-->5' proofreading activity assured by the e subunit of the m...