Gonadal and Endocrine Analysis of a Gynandromorphic Chicken

Kirsten R. Morris, Claire E. Hirst, Andrew T. Major, Tariq Ezaz, Mark Ford, Susan Bibby, Tim J. Doran, Craig A. Smith

Research output: Contribution to journalArticleResearchpeer-review

2 Citations (Scopus)

Abstract

Birds have a ZZ male and ZW female sex chromosome system. The relative roles of genetics and hormones in regulating avian sexual development have been revealed by studies on gynandromorphs. Gynandromorphs are rare bilateral sex chimeras, male on one side of the body and female on the other. We examined a naturally occurring gynandromorphic chicken that was externally male on the right side of the body and female on the left. The bird was diploid but with a mix of ZZ and ZW cells that correlated with the asymmetric sexual phenotype. The male side was 96% ZZ, and the female side was 77% ZZ and 23% ZW. The gonads of this bird at sexual maturity were largely testicular. The right gonad was a testis, with SOX9 + Sertoli cells, DMRT1 + germ cells, and active spermatogenesis. The left gonad was primarily testicular, but with some peripheral aromatase-expressing follicles. The bird had low levels of serum estradiol and high levels of testosterone, as expected for a male. Despite the low percentage of ZW cells on that side, the left side had female sex-linked feathering, smaller muscle mass, smaller leg and spur, and smaller wattle than the male side. This indicates that these sexually dimorphic structures must be at least partly independent of sex steroid effects. Even a small percentage of ZW cells appears sufficient to support female sexual differentiation. Given the lack of chromosome-wide dosage compensation in birds, various sexually dimorphic features may arise due to Z-gene dosage differences between the sexes.

Original languageEnglish
Pages (from-to)3492-3502
Number of pages11
JournalEndocrinology
Volume159
Issue number10
DOIs
Publication statusPublished - 1 Oct 2018

Keywords

  • reproductive biology
  • sex-based medicine

Cite this

Morris, Kirsten R. ; Hirst, Claire E. ; Major, Andrew T. ; Ezaz, Tariq ; Ford, Mark ; Bibby, Susan ; Doran, Tim J. ; Smith, Craig A. / Gonadal and Endocrine Analysis of a Gynandromorphic Chicken. In: Endocrinology. 2018 ; Vol. 159, No. 10. pp. 3492-3502.
@article{e9a9c828d98d4b90b5e9b6347bfe0b9f,
title = "Gonadal and Endocrine Analysis of a Gynandromorphic Chicken",
abstract = "Birds have a ZZ male and ZW female sex chromosome system. The relative roles of genetics and hormones in regulating avian sexual development have been revealed by studies on gynandromorphs. Gynandromorphs are rare bilateral sex chimeras, male on one side of the body and female on the other. We examined a naturally occurring gynandromorphic chicken that was externally male on the right side of the body and female on the left. The bird was diploid but with a mix of ZZ and ZW cells that correlated with the asymmetric sexual phenotype. The male side was 96{\%} ZZ, and the female side was 77{\%} ZZ and 23{\%} ZW. The gonads of this bird at sexual maturity were largely testicular. The right gonad was a testis, with SOX9 + Sertoli cells, DMRT1 + germ cells, and active spermatogenesis. The left gonad was primarily testicular, but with some peripheral aromatase-expressing follicles. The bird had low levels of serum estradiol and high levels of testosterone, as expected for a male. Despite the low percentage of ZW cells on that side, the left side had female sex-linked feathering, smaller muscle mass, smaller leg and spur, and smaller wattle than the male side. This indicates that these sexually dimorphic structures must be at least partly independent of sex steroid effects. Even a small percentage of ZW cells appears sufficient to support female sexual differentiation. Given the lack of chromosome-wide dosage compensation in birds, various sexually dimorphic features may arise due to Z-gene dosage differences between the sexes.",
keywords = "reproductive biology, sex-based medicine",
author = "Morris, {Kirsten R.} and Hirst, {Claire E.} and Major, {Andrew T.} and Tariq Ezaz and Mark Ford and Susan Bibby and Doran, {Tim J.} and Smith, {Craig A.}",
year = "2018",
month = "10",
day = "1",
doi = "10.1210/en.2018-00553",
language = "English",
volume = "159",
pages = "3492--3502",
journal = "Endocrinology",
issn = "0013-7227",
publisher = "Endocrine Society",
number = "10",

}

Gonadal and Endocrine Analysis of a Gynandromorphic Chicken. / Morris, Kirsten R.; Hirst, Claire E.; Major, Andrew T.; Ezaz, Tariq; Ford, Mark; Bibby, Susan; Doran, Tim J.; Smith, Craig A.

In: Endocrinology, Vol. 159, No. 10, 01.10.2018, p. 3492-3502.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Gonadal and Endocrine Analysis of a Gynandromorphic Chicken

AU - Morris, Kirsten R.

AU - Hirst, Claire E.

AU - Major, Andrew T.

AU - Ezaz, Tariq

AU - Ford, Mark

AU - Bibby, Susan

AU - Doran, Tim J.

AU - Smith, Craig A.

PY - 2018/10/1

Y1 - 2018/10/1

N2 - Birds have a ZZ male and ZW female sex chromosome system. The relative roles of genetics and hormones in regulating avian sexual development have been revealed by studies on gynandromorphs. Gynandromorphs are rare bilateral sex chimeras, male on one side of the body and female on the other. We examined a naturally occurring gynandromorphic chicken that was externally male on the right side of the body and female on the left. The bird was diploid but with a mix of ZZ and ZW cells that correlated with the asymmetric sexual phenotype. The male side was 96% ZZ, and the female side was 77% ZZ and 23% ZW. The gonads of this bird at sexual maturity were largely testicular. The right gonad was a testis, with SOX9 + Sertoli cells, DMRT1 + germ cells, and active spermatogenesis. The left gonad was primarily testicular, but with some peripheral aromatase-expressing follicles. The bird had low levels of serum estradiol and high levels of testosterone, as expected for a male. Despite the low percentage of ZW cells on that side, the left side had female sex-linked feathering, smaller muscle mass, smaller leg and spur, and smaller wattle than the male side. This indicates that these sexually dimorphic structures must be at least partly independent of sex steroid effects. Even a small percentage of ZW cells appears sufficient to support female sexual differentiation. Given the lack of chromosome-wide dosage compensation in birds, various sexually dimorphic features may arise due to Z-gene dosage differences between the sexes.

AB - Birds have a ZZ male and ZW female sex chromosome system. The relative roles of genetics and hormones in regulating avian sexual development have been revealed by studies on gynandromorphs. Gynandromorphs are rare bilateral sex chimeras, male on one side of the body and female on the other. We examined a naturally occurring gynandromorphic chicken that was externally male on the right side of the body and female on the left. The bird was diploid but with a mix of ZZ and ZW cells that correlated with the asymmetric sexual phenotype. The male side was 96% ZZ, and the female side was 77% ZZ and 23% ZW. The gonads of this bird at sexual maturity were largely testicular. The right gonad was a testis, with SOX9 + Sertoli cells, DMRT1 + germ cells, and active spermatogenesis. The left gonad was primarily testicular, but with some peripheral aromatase-expressing follicles. The bird had low levels of serum estradiol and high levels of testosterone, as expected for a male. Despite the low percentage of ZW cells on that side, the left side had female sex-linked feathering, smaller muscle mass, smaller leg and spur, and smaller wattle than the male side. This indicates that these sexually dimorphic structures must be at least partly independent of sex steroid effects. Even a small percentage of ZW cells appears sufficient to support female sexual differentiation. Given the lack of chromosome-wide dosage compensation in birds, various sexually dimorphic features may arise due to Z-gene dosage differences between the sexes.

KW - reproductive biology

KW - sex-based medicine

UR - http://www.scopus.com/inward/record.url?scp=85054402824&partnerID=8YFLogxK

U2 - 10.1210/en.2018-00553

DO - 10.1210/en.2018-00553

M3 - Article

VL - 159

SP - 3492

EP - 3502

JO - Endocrinology

JF - Endocrinology

SN - 0013-7227

IS - 10

ER -