Advertisement

Sex Chromosomes and Sex-Linked Genes

  • Susumu¬†Ohno

Part of the Monographs on Endocrinology book series (ENDOCRINOLOGY, volume 1)

Table of contents

  1. Front Matter
    Pages I-X
  2. Introduction

    1. Susumu Ohno
      Pages 1-4
  3. Evolution of Vertebrate Sex Chromosomes and Genomes

  4. Evolution of Dosage Compensation Mechanism for Sex-linked Genes

  5. On So-called Sex-determining Factors and the Act of Sex Determination

  6. Back Matter
    Pages 175-192

About this book

Introduction

Natural selection operates among individual organisms which differ in their genetic constitution. The degree of hereditary variability within a species is greatly enhanced by cross-fertilization. Indeed, the mechanism of sexual reproduction occurred very early in evolution, for it is seen today even in bacteria. In Escherichia coli, fertilization occurs by passage of the single chromosome from the male into the female bacterium (LEDERBERG, 1959). In multicellular organisms, the separation of germ from soma, and the production of haploid gametes became mandatory. The gametes were of two types. One, extremely mobile, was designed to seek out and penetrate the other, which loaded with nutrients, received the mobile gamete and intiated the development of a new individual. The foundation for true bisexuality was thus laid. In the primitive state of bisexuality, whether an individual is to be a sperm-producing male or an egg-producing female appears to be decided rather haphazardly. In the worm, Banelia viridis, the minute males are parasites in the female. Larvae that become attached to the proboscis of an adult female become males, while unattached larvae sink to the bottom and become females (BALTZER, 1935). The more sophisticated state of bisexuality was initiated by setting aside a particular pair of chromosomes for specialization and making either the male or the female a heterogametic sex. Sex chromosomes as we know them were thus born.

Keywords

Chromosomes bacteria chromosome genes natural selection parasites reproduction sex sexuality

Authors and affiliations

  • Susumu¬†Ohno
    • 1
  1. 1.Department of BiologyCity of Hope MedicalDuarteUSA

Bibliographic information

  • DOI https://doi.org/10.1007/978-3-642-88178-7
  • Copyright Information Springer-Verlag Berlin Heidelberg 1967
  • Publisher Name Springer, Berlin, Heidelberg
  • eBook Packages Springer Book Archive
  • Print ISBN 978-3-642-88180-0
  • Online ISBN 978-3-642-88178-7
  • Series Print ISSN 0077-1015
  • Buy this book on publisher's site