New Set Of Genes Research Articles

Genetic control of esterase-6 isozymes in hexaploid wheat and rye

The EST-6 leaf esterase phenotypes from euploid, nullisomic-tetrasomic and rye chromosome addition and substitution lines of common wheat were determined using polyacrylamide gel electrophoresis. Evidence is presented to demonstrate that Est-6 is a new set of genes, that are expressed in the leaf. The Est-6 gene set were clearly distinguished from the Est-5 genes which are expressed in the grain. The three homoeoallelic loci, Est-A6, Est-B6 and Est-D6, were located on chromosomes 3A, 3B and 3D. An Est-R6 gene was located on chromosome 6R is involved in rye. Some considerations concerning homoeology between homoeologous group 3 of wheat and the rye chromosome 6R are made.

Multivariate analysis of genetic and environmental influences for longitudinal height and weight data.

A multivariate analysis of genetic and environmental influences on longitudinal height and weight data from a Swedish twin sample is presented. For height in boys, genetic correlations of all ages with the first time point decrease during puberty and increase afterwards. A more linear pattern is evident for the girls. For weight in boys, genetic and environmental correlations are similar to the ones for height. Genetic correlations for girls are stable with age, while environmental correlations peak at 13.5 years and decrease drastically thereafter. The patterns for height and weight in boys suggest that a new set of genes may be turned on during puberty and turned off again afterwards. The pattern found for weight in girls indicates that a simple additive genetic model is not appropriate. It is necessary, however, to apply the model to actual data from several time points to recognize the inadequacy of the model.

Regulation of adenovirus mRNA synthesis.

The lytic cycle of adenovirus is a tightly regulated sequence of stages. When this regulation is studied at the level of mRNA production, the most significant step in controlling gene expression is initiation of transcription. Thus in preceding from one stage of expression to another, viral factors seem to turn on transcription of new sets of genes. At the moment, it is thought that viral mRNA synthesis involves initiation of transcription at ten different promoter sites. It is likely that in some manner the frequency of an initiation of transcription at nine of these sites is affected by one or more viral gene products. With the recent development of soluble in vitro transcription systems that respond to exogenously added DNA, it should be possible to begin to study regulation of gene expression at this stage of transcription. At present, these systems yield the paradoxical observation that extracts prepared from uninfected human cells more efficiently recognize the late promoter as compared to the early promoter of adenovirus. As more is learned about regulation of synthesis of viral mRNAs, examples will surely be found where RNA processing and RNA turnover play a critical role in determining the level of mRNAs. Such cases are more likely to appear in the balancing of synthesis of different mRNAs derived from one transcriptional unit. Few experiments have been directed to this possibility and the study of adenovirus molecular biology is only now entering the age of maturity where these experiments are feasible.

Effect of stage of development and function on the template activity of rat mammary gland chromatin.

SummaryThe ability of purified mammary gland chromatin to serve as a template for DNA-dependent RNA polymerase increases slightly during gestation and increases nearly twofold after the onset of lactation. The composition of the purified chromatin changes at parturition and is characterized by a 2-3-fold increase in RNA, a 1.2-1.3-fold increase in histone, amd a 1.1-1.7-fold increase in nonhistone chromatin proteins. Since the synthesis of milk proteins begins coincidentally with the increase in chromatin template activity, the response probably results from the expression of a new set of genes although the possibility of an increase in the rate of expression of previously active genes cannot be excluded.