GENETIC AND CYTOLOGIC FOUNDATIONS 



FOR SEX 



John W. Gowen, Ph.D. 



Department of Genetics, Iowa State University, Ames, Iowa 



I. Basic Literature 



II. Mechanistic Interpretations op Sex 



A. Concept of Sex Determination 



B. Sex as Associated with Visible Chro- 



mosomal Differences 



C. Changing Methods of Cytogenetics 



D. Chromosomal Association with Sex 



E. Balance of Male- and Female-Deter- 



mining Elements in Sex Deter- 

 mination 



III. Sex Genes in Drosophila 



A. Mutant Tjqjes 



B. Major Sex Genes 



C. Other Chromosome Group Associa- 



tions: Drosophila americana 



D. Location of Sex-determining Genes 

 IV. Sex under Special Conditions 



A. Species Hybridity 



B. Mosaics for Sex 



C. Parthenogenesis in Drosophila 



D. Sex Influence of the Y Chromosome 



E. Maternal Influences on Sex Ratio 



F. Male-influenced Type of Female Sex 



Ratio " 



G. High Male Sex Ratio of Cienetic 



Origin 



H. Female-Male Sex Ratio Interactions 

 V. Sex Determination in Other In- 

 sects 



A. Sciara 



B. Apis and Habrobracon 



C. Bombyx 



VI. Sex Determination in Dioecious 



Plants 



A. Melandrium 



B. Rumex 



C. Spinacia 



D. Asparagus 



E. Humulus 



VII. Mating Types 



VIII. Environmental Modifications of 

 Sex 



A. Amphibia 



B. Fish 



IX. Sex and Parthenogenesis in Birds 



X. Sex Determination in Mammals... 

 A. Goat Hermaphrodites 



B. Sex in the Mouse 50 



C. Sex and Sterility in the Cat 50 



D. Deviate Sex Types in Cattle and 



Swine 51 



E. Sex in Man: Chromosomal Basis 52 



1. Nuclear chromatin, sex chro- 



matin 55 



2. Chromosome complement and 



phenotype in man 5(1 



3. Testicular feminization 50 



4. Superfemale 57 



5. Klinefelter syndrome 58 



0. Turner syndrome 59 



7. Hermaphrodites 59 



8. XXXY + 44 autosome type 01 



9. XXV + 66 autosome type 03 



10. Summary of types 03 



11. Types unrelated to sex 03 



F. Sex Ratio in Man 65 



XL References 00 



I. Basic Literature 



In the first edition of Sex and Internal 

 Secretions published in 1932, Bridges dis- 

 cussed the closely prescribed problem of the 

 genetics of sex, particularly as it was related 

 to one species, Drosophila melanogaster. 

 The treatment was sharply focused on the 

 advances made, chiefly through his own re- 

 searches, in understanding the functions of 

 the genetic and cytologic factors operating 

 during embryologic development which ul- 

 timately establish the sex types. The em- 

 phasis was on gene action through inter- 

 chromosomal balances as they may aff"cct 

 sex expression. The second edition of 1939 

 brought this material up-to-date and, at 

 the same time, offered a much broader treat- 

 ment by the inclusion of accumulated evi- 

 dence on how differentiation for sex comes 

 about in other forms. There is no substitute 

 for a careful reading of these two presenta- 



