An early response to the administration of oestradiol-17 beta to immature rats is a dramatic stimulation in the synthesis of uterine hnRNA (heterogenous nuclear RNA). High-molecular-weight fractions of the hnRNA were purified and subfractionated on poly(U)-Sepharose into fractions that differed in their poly(A) content and their size profile on polyacrylamide gels. Oestrogen treatment of the rats stimulated the synthesis of all three fractions of high-molecular-weight hnRNA, but the kinetics of synthesis, degree of stimulation and size distribution of the newly synthesize RNA differed in each fraction.

The mRNA population of immature rat uteri, responding to different lengths of oestradiol‐induced differentiation, have been compared by the technique of DNA hybridization with heterogeneous RNA. Over the first 4 h of hormone induction there are continuing qualitative and quantitative changes in the poly(A)‐containing mRNA such that, by 4 h after oestradiol administration, the population bears little resemblance to that of the unstimulated animal. Between 2 h and 4 h after oestradiol administration, the most striking changes appear to be in sequences of intermediate abundance. The possible significance of these findings is discussed.

The diversity and complexity of the uterine mRNA population has been compared at two different stages of uterine growth and development in the rat. Analysis by cDNA hybridization to homologous mRNA indicates that there are 8000 different sequences expressed in the immature rat uterus responding to just 4 h of oestradiol‐17β‐induced growth while the fully developed uterus expresses 36000 sequences. As a check on our results, the complexity is re‐analysed by hybridization of mercurated mRNA to total unique DNA. Analysis by this method indicates that the hormone‐stimulated immature rat uterus contains 12000 poly(A)‐containing mRNA sequences while the fully differentiated adult tissue contains 53000 diverse sequences.

The spectrum of β-thalassemia mutations in Malaysia has been determined in 45 β-thalassemia chromosomes using dot blot hybridization of the polymerase chain reaction amplified DNA and direct DNA sequencing. Eleven different molecular defects, including those previously detected in Chinese, Asian Indians, and American blacks, and a novel frameshift mutation causing β°-thalassemia were detected. Since this novel mutation, a T deletion in codon 15 creates a new restriction site for EcoRllenzyme; the mutation could be detected by EcoRll digestion of the appropriate amplified fragment. The results of the present study provide additional information on the molecular heterogeneity of β-thalassemia in this population. We also demonstrated the nonradioactive detection method of the β-thalassemia mutation based upon the digoxigenin-labeled oligonucleotide probes.

Cotton (Gossypium hirsutum ssp.) belongs to the genus Gossypium from the family Malvaceae. About 100 genera are in the family Malvaceae and about 1500 species. It is grown worldwide for oil, seed, and fiber. A major problem in cotton cultivation is a drought that’s why this experiment was planned to evaluate the cotton mutants for drought tolerance. A variety of cotton Cyto-155 was mutated with gamma rays at different intensities such that 20kR, 25kR, 30kR, and 35kR, to obtain some genetic variation. Mutated seed along with non-mutated of that cotton variety was sown in split plot layout under randomized complete block design with three replications, under the normal irrigated condition with six irrigations and water stress condition with two irrigations at maturity data was collected for plant height, number of monopodial branches, number of sympodial branches, bolls per plant, boll weight, seed index, GOT%, lint index, seed cotton yield, relative water content and excised leaf water loss.Results showed a highly significant effect of genotype and water regime on all observed traits. Water regime × genotype interaction was also highly significant for plant height, number of sympodial branches, seed index, boll weight, lint index, and excised leaf water loss. Water regime × genotype interaction was non-significant for number of monopodial branches, bolls per plant, GOT%, seed cotton yield, and relative water content. Mean comparison indicated that seed mutated at 30kR and 35kR performed well for all yield-related traits in both irrigated conditions.