Ratios of α-to β-globin mRNA and regulation of globin synthesis in reticulocytes

Ratios of α‐ to β‐globin RNA sequences in the erythropoietic mouse spleen

“…Our results suggest an a//3 RNA ratio of 1.3 in total cellular RNA which remains constant during in vivo development. This a//3 ratio is similar to that reported previously in total RNA of mouse reticulocytes [1,6]. The results also confirm the decreasing ~//3 RNA ratio in poly(A) + RNA observed by gel analysis [5].…”

“…The a and/3 mRNA templates were separated and 3H-labeled cDNA probes were synthesized and isolated as in [6]. The specificities of the ~ and/3 cDNA probes, estimated by back hybridization to their respective templates, were 94-97% for the a cDNAs and 89-94% for the/3 cDNAs.…”

“…Total nuclear RNA was prepared from nuclei [9] by hot phenol extraction [10] followed by DNase digestion [ 11 ]. Hybridizations in 24/ll mixtures containing a constant amount of cDNA (500 cpm) and varying amounts of RNA were assayed by $1 nuclease digestion as in [6].…”

HeLa Cell Cytoplasmic mRNA Contains Three Classes of Sequences Predominantly Poly(A)‐Free, Predominantly Poly(A)‐Containing and Bimorphic

“…Examples of each of these classes of mRNA have been described in the literature. Messages which are found in both states in the same cell are p-actin [22,23] and a-hemoglobin mRNA [41]. Messages found almost exclusively in the poly(A)-containing fraction include muscle actin and nonmuscle y-actin [22] and /3-hemoglobin mRNA [41].…”

“…Messages which are found in both states in the same cell are p-actin [22,23] and a-hemoglobin mRNA [41]. Messages found almost exclusively in the poly(A)-containing fraction include muscle actin and nonmuscle y-actin [22] and /3-hemoglobin mRNA [41]. Histone mRNA is found exclusively in the poly(A)-free fraction in HeLa cells [13] and in heat-shocked Drosphila cells [42].…”