We have cloned murine genomic and complementary DNA that is equivalent to the human ABO gene. The murine gene consists of at least six coding exons and spans at least 11 kilobase pairs. Exon-intron boundaries are similar to those of the human gene. Unlike human A and B genes that encode two distinct glycosyltransferases with different donor nucleotide-sugar specificities, the murine gene is a cis-AB gene that encodes an enzyme with both A and B transferase activities, and this cis-AB gene prevails in the mouse population. Cloning of the murine AB gene may be helpful in establishing a mouse model system to assess the functionality of the ABO genes in the future.Histo-blood group A/B antigens are clinically important antigens in blood transfusion and organ transplantation. These antigens are oligosaccharide antigens whose immunodominant structures are defined as GalNAc ␣133 (Fuc ␣132) Gal-and Gal ␣133 (Fuc ␣132) Gal-for A and B antigen, respectively. Functional alleles at the ABO locus encode enzymes that catalyze the final step of synthesis. A alleles encode for A transferase, which transfers the GalNAc residues from the UDPGalNAc nucleotide-sugar to the galactose residue of the acceptor H substrates defined by Fuc ␣132 Gal-. B alleles encode for B transferase that transfers the galactose residue from UDP-galactose to the same H substrates. O alleles are nonfunctional, null alleles. During the past decade, we have been studying the molecular genetic basis of the histo-blood group ABO system (1). From a human gastric carcinoma cell line cDNA library, we were able to clone human A transferase cDNA (2) based on the partial amino acid sequence of the soluble form of A transferase purified from human lung (3). Using cross-hybridization with A transferase cDNA probes, we then cloned B transferase cDNA and nonfunctional O allelic cDNA from cDNA libraries made with RNA from colon adenocarcinoma cell lines that exhibited different ABO phenotypes (4). Possible allele-specific mutations were identified. Four amino acid substitutions were discovered between A and B transferases. O alleles were more homologous to A alleles than to B alleles. A single base deletion was found near the N terminus of the coding sequence in most of the O alleles, which caused the codon frame to shift. This resulted in a truncated protein without glycosyltransferase activity. In addition to the three major alleles (A
We determined nucleotide sequences of the 16S rRNA gene of mitochondrial DNA (mtDNA) (about 1.6 kb) for 35 chimpanzee, 13 bonobo, 10 gorilla, 16 orangutan, and 23 gibbon individuals. We compared those data with published sequences and estimated nucleotide diversity for each species. All the ape species showed higher diversity than human. We also constructed phylogenetic trees and networks. The two orangutan subspecies were clearly separated from each other, and Sumatran orangutans showed much higher nucleotide diversity than Bornean orangutans. Some gibbon species did not form monophyletic clusters, and variation within species was not much different from that among species in the subgenus Hylobates.
The human and nonhuman primate ABO blood group gene shows relatively large numbers of nucleotide differences around the exon 7 region. In this study we determined intron 6 sequences for 9 alleles of common chimpanzee and for 3 alleles of bonobo to estimate nucleotide diversities among them. Sequence length polymorphisms are observed in this region as a repeat appears one to five times. From a phylogenetic network of intron 6 sequences of ABO blood group genes for humans, common chimpanzee, and bonobo, parallel substitutions and/or some kinds of convergent events are predicted in the chimpanzee lineage. We also estimated nucleotide diversities for common chimpanzee and bonobo ABO blood group genes; these values were 0.219% and 0.208%, respectively.
There are several methods available to analyze the mRNA concentration quantitatively. Among them, the competitive reverse transcription (RT-)PCR method is very useful. For this method, Cy5-labeled primers were used, and after gel electrophoresis in 7 M urea, the Cy5-labeled single-strand DNA was measured by a fluorescence detector. However, as the equipment to measure the Cy5-labeled fluorescence is expensive, we developed a new method using SYBR Gold staining. After gel electrophoresis in 7 M urea, the single-strand PCR product DNA was stained with SYBR Gold, and photographed with a standard UV-transilluminator and a standard digital camera with a specific filter for SYBR Gold staining. The photographic image was digitized by an imaging software. We measured beta-actin and plasma glutathione peroxidase (Gpx3) mRNA concentrations of HepG2 cell cultured at 5 and 20% oxygen tension. The Gpx3 expression was increased by hypoxia. The result was equivalent to the data obtained by the real-time PCR analysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.