Developmental biochemistry of cottonseed embryogenesis and germination: changing messenger ribonucleic acid populations as shown by reciprocal heterologous complementary deoxyribonucleic acid--messenger ribonucleic acid hybridization.

The concentrations of messenger ribonucleic acids (mRNAs) in three stages in cotton cotyledon ontogeny were examined by total poly(A)+ mRNA hybridization with unfractionated complementary DNA. This study and others show that these RNAs are representative of the total mRNA population. A novel analysis of all reciprocal hybridization reactions detected at least 17 groups of mRNAs, the sequences of which change together in concentration during this developmental period. We have defined an mRNA subset as a group or groups of mRNAs that change together in concentration in a similar fashion, regardless of the abundance of its members. About 11 such subsets are detected, several of which contain at least two groups which change in concentration in parallel. These experiments have identified the same mRNA subsets detected in a companion study of the abundant proteins synthesized in vivo and in vitro during this developmental period and indicate that similar changes occur for less abundant mRNAs as well.