Developmental Expression of Multiple Forms of 3‐Hydroxy‐3‐Methylglutaryl Coenzyme A Reductase mRNA in Rat Testes

Abstract

ABSTRACT: The developmental expression of 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase, the enzyme that catalyzes the rate‐limiting reaction of mevalonate formation, was investigated in rat testes. Adult testes were found to contain three distinct forms of HMG‐CoA reductase mRNA of 4.8, 4.2, and 4.0 kilobases (kb) in length. In testes from 26‐day‐old rats the 4.8‐kb species was the major form present. By 40 days of age, large increases in the levels of the testes‐specific 4.2‐ and 4.0‐kb forms occurred, with a small decrease in the amount of the 4.8‐kb form. The level of the 4.8‐kb form appeared to be associated with the level of testicular HMG‐CoA reductase activity.