Endocrine and genetic control of sex differentiation in the Malacostracan Crustacea

Abstract

Summary Sex differentiation in Malacostraca is controlled by hormone secreted from the androgenic glands. Experimentally induced sex inversions in isopods and amphipods proved that the genetic female and male possess primordia of the androgenic glands, gonads, and gonoducts, along with sexual characteristics of both sexes. During the sensitive period, the presence or absence of androgenic gland hormone (AGH) affects the differentiation of these primordia. Genetic control of the development of androgenic gland primordium seems to be brought about assuming of the following: 1. Both genetic female and male possess gene(s) (AGH-G) responsible for the AGH-synthesis situated on the homologous loci of the sex chromosomes and/or on the autosomes. 2. The gene(s) are activated spontaneously with the lack of inhibition of the major sex factor carried by the W or X chromosome. The W and X factors are hypostatic to major sex factor carried by the Y chromosome. The Z factor does not seem to influence sex differentiation. Sufficient allochthonous AGH seems to render the W and X factors ineffective.