Cellula apicale e metabolismo degli acidi nucleici nella spermatogenesi degli Ortotteri(Acrididae e Locustidae)

Abstract

(1) The apical or Verson cell of the testis ofOrthoptera is a connective tissue element having a trophic function. Its secretion is rich in ribonucleic acid (RNA), which is absorbed by the germ cells. This is a primary source of RNA for spermatogony. (2) Nuclear chromatin is probably concerned in RNA elaboration. The variation in amount and distribution of the perinuclear RNA granules suggest the existence of a secretory cycle analogous to that described inAsellus. (3) In the connective tissue cells of the zone below the apical complex, degenerative processes are observed, the end-product of which is essentially RNA. The spherules which stain green or violet withUnna's mixture and are Feulgen-positive, are interpreted as pyknotic nuclei. Their chromatin is transformed into RNA and constitutes spherules and small granules positive to pyronine, which are absorbed by spermatocytes in meiotic, prophase. Thus, during spermatogenesis in the investigatedOrthoptera, both the apical cell and some degenerating connective tissue elements produce RNA, which is absorbed by the developing germ cells.