Evaluation of Acute Toxicity and Antioxidant Response of Earthworm Exposed to a Lignin-Modified Crosslinked Hydrogel.

Hydrogels are polymers of great importance due to their multiple applications, which have led to an exponential increase in their production. However, once they have fulfilled their function, they become waste and their ecotoxicological effects are unknown. The aim of the present study was to evaluate the acute toxicity and total antioxidant capacity of the earthworm () exposed to a terpolymeric hydrogel (acrylic acid, acrylamide, and 2-acrylamido-2-methyl-1-propane-sulfonic acid) crosslinked with modified kraft lignin.

Recombinant Hemagglutinin of Avian Influenza Virus H5 Expressed in the Chloroplast of Chlamydomonas reinhardtii and Evaluation of Its Immunogenicity in Chickens.

Globally, avian influenza (AI) is a serious problem in poultry farming. Despite vaccination, the prevalence of AI in México highlights the need for new approaches to control AI and to reduce the economic losses associated with its occurrence in susceptible birds. Recombinant proteins from avian influenza virus (AIV) have been expressed in different organisms, such as plants.

Yeast mitochondrial RNA polymerase primes mitochondrial DNA polymerase at origins of replication and promoter sequences.

Three proteins phylogenetically grouped with proteins from the T7 replisome localize to yeast mitochondria: DNA polymerase γ (Mip1), mitochondrial RNA polymerase (Rpo41), and a single-stranded binding protein (Rim1). Human and T7 bacteriophage RNA polymerases synthesize primers for their corresponding DNA polymerases. In contrast, DNA replication in yeast mitochondria is explained by two models: a transcription-dependent model in which Rpo41 primes Mip1 and a model in which double stranded breaks create free 3' OHs that are extended by Mip1.

The thumb subdomain of yeast mitochondrial RNA polymerase is involved in processivity, transcript fidelity and mitochondrial transcription factor binding.

Single subunit RNA polymerases have evolved 2 mechanisms to synthesize long transcripts without falling off a DNA template: binding of nascent RNA and interactions with an RNA:DNA hybrid. Mitochondrial RNA polymerases share a common ancestor with T-odd bacteriophage single subunit RNA polymerases. Herein we characterized the role of the thumb subdomain of the yeast mtRNA polymerase gene (RPO41) in complex stability, processivity, and fidelity.

Yeast mitochondrial RNAP conformational changes are regulated by interactions with the mitochondrial transcription factor.

Mitochondrial RNA polymerases (MtRNAPs) are members of the single-subunit RNAP family, the most well-characterized member being the RNAP from T7 bacteriophage. MtRNAPs are, however, functionally distinct in that they depend on one or more transcription factors to recognize and open the promoter and initiate transcription, while the phage RNAPs are capable of performing these tasks alone. Since the transcriptional mechanisms that are conserved in phage and mitochondrial RNAPs have been so effectively characterized in the phage enzymes, outstanding structure-mechanism questions concern those aspects that are distinct in the MtRNAPs, particularly the role of the mitochondrial transcription factor(s).

Conservation of promoter melting mechanisms in divergent regions of the single-subunit RNA polymerases.

The single-subunit RNA polymerases make up a widespread family of proteins found in phage, mitochondria, and chloroplasts. Unlike the phage RNAPs, the eukaryotic RNAPs require accessory factors to melt their promoters and diverge from the phage RNAPs in the regions where functions associated with promoter melting in the latter have been mapped, suggesting that promoter melting mechanisms in the eukaryotic RNAPs diverge from those in the phage enzymes. However, here we show that an element in the yeast mitochondrial RNAP, identified by sequence alignment with the T7 phage RNAP, fulfills a role in promoter melting similar to that filled by the T7RNAP "intercalating hairpin".