Temperature-dependent sex determination in the american alligator: AMH precedes SOX9 expression

Patrick S. Western, Jenny L. Harry, Jennifer A.Marshall Graves, Andrew H. Sinclair

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Gonadal morphogenesis is very similar among mammals, birds, and reptiles. Despite this similarity, each group utilises quite different genetic triggers for sex determination. In mammals, testis development is initiated by action of the Y-chromosome gene SRY. Current evidence suggests that SRY may act together with a related gene, SOX9, to activate another gene(s) in the pathway of testicular differentiation. A downstream candidate for regulation by SRY and SOX9 is AMH. In mouse, Sox9 is expressed in the Sertoli cells of the embryonic testis and it precedes the onset of Amh expression. During mouse gonadogenesis, Amh is confined to the embryonic testis, although it later shows postnatal expression in the ovary. Reptiles such as the American alligator, which exhibit temperature-dependent sex determination (TSD) do not have dimorphic sex chromosomes and apparently no SRY orthologue. SOX9 is expressed during testis differentiation in the alligator; however, it appears to be expressed too late to cause testis determination. Here we describe the cloning and expression of the alligator AMH gene and show that AMH expression precedes SOX9 expression during testis differentiation. This is the opposite to that observed in the mouse where SOX9 precedes AMH expression. The data presented here, as well as findings from recent expression studies in the chick, suggest that AMH expression is not regulated by SOX9 in the non-mammalian vertebrates.

Original languageEnglish
Pages (from-to)411-419
Number of pages9
JournalDevelopmental Dynamics
Volume216
Issue number4-5
Publication statusPublished - 20 Dec 1999

Keywords

  • Alligator
  • Anti-Mullerian hormone
  • Gonad differentiation
  • SOX9
  • Temperature-dependent sex determination

Cite this

Western, Patrick S. ; Harry, Jenny L. ; Graves, Jennifer A.Marshall ; Sinclair, Andrew H. / Temperature-dependent sex determination in the american alligator : AMH precedes SOX9 expression. In: Developmental Dynamics. 1999 ; Vol. 216, No. 4-5. pp. 411-419.
@article{0d77a9144720402384bae61d204622df,
title = "Temperature-dependent sex determination in the american alligator: AMH precedes SOX9 expression",
abstract = "Gonadal morphogenesis is very similar among mammals, birds, and reptiles. Despite this similarity, each group utilises quite different genetic triggers for sex determination. In mammals, testis development is initiated by action of the Y-chromosome gene SRY. Current evidence suggests that SRY may act together with a related gene, SOX9, to activate another gene(s) in the pathway of testicular differentiation. A downstream candidate for regulation by SRY and SOX9 is AMH. In mouse, Sox9 is expressed in the Sertoli cells of the embryonic testis and it precedes the onset of Amh expression. During mouse gonadogenesis, Amh is confined to the embryonic testis, although it later shows postnatal expression in the ovary. Reptiles such as the American alligator, which exhibit temperature-dependent sex determination (TSD) do not have dimorphic sex chromosomes and apparently no SRY orthologue. SOX9 is expressed during testis differentiation in the alligator; however, it appears to be expressed too late to cause testis determination. Here we describe the cloning and expression of the alligator AMH gene and show that AMH expression precedes SOX9 expression during testis differentiation. This is the opposite to that observed in the mouse where SOX9 precedes AMH expression. The data presented here, as well as findings from recent expression studies in the chick, suggest that AMH expression is not regulated by SOX9 in the non-mammalian vertebrates.",
keywords = "Alligator, Anti-Mullerian hormone, Gonad differentiation, SOX9, Temperature-dependent sex determination",
author = "Western, {Patrick S.} and Harry, {Jenny L.} and Graves, {Jennifer A.Marshall} and Sinclair, {Andrew H.}",
year = "1999",
month = "12",
day = "20",
language = "English",
volume = "216",
pages = "411--419",
journal = "Developmental Dynamics",
issn = "1058-8388",
publisher = "Wiley-Blackwell",
number = "4-5",

}

Temperature-dependent sex determination in the american alligator : AMH precedes SOX9 expression. / Western, Patrick S.; Harry, Jenny L.; Graves, Jennifer A.Marshall; Sinclair, Andrew H.

In: Developmental Dynamics, Vol. 216, No. 4-5, 20.12.1999, p. 411-419.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Temperature-dependent sex determination in the american alligator

T2 - AMH precedes SOX9 expression

AU - Western, Patrick S.

AU - Harry, Jenny L.

AU - Graves, Jennifer A.Marshall

AU - Sinclair, Andrew H.

PY - 1999/12/20

Y1 - 1999/12/20

N2 - Gonadal morphogenesis is very similar among mammals, birds, and reptiles. Despite this similarity, each group utilises quite different genetic triggers for sex determination. In mammals, testis development is initiated by action of the Y-chromosome gene SRY. Current evidence suggests that SRY may act together with a related gene, SOX9, to activate another gene(s) in the pathway of testicular differentiation. A downstream candidate for regulation by SRY and SOX9 is AMH. In mouse, Sox9 is expressed in the Sertoli cells of the embryonic testis and it precedes the onset of Amh expression. During mouse gonadogenesis, Amh is confined to the embryonic testis, although it later shows postnatal expression in the ovary. Reptiles such as the American alligator, which exhibit temperature-dependent sex determination (TSD) do not have dimorphic sex chromosomes and apparently no SRY orthologue. SOX9 is expressed during testis differentiation in the alligator; however, it appears to be expressed too late to cause testis determination. Here we describe the cloning and expression of the alligator AMH gene and show that AMH expression precedes SOX9 expression during testis differentiation. This is the opposite to that observed in the mouse where SOX9 precedes AMH expression. The data presented here, as well as findings from recent expression studies in the chick, suggest that AMH expression is not regulated by SOX9 in the non-mammalian vertebrates.

AB - Gonadal morphogenesis is very similar among mammals, birds, and reptiles. Despite this similarity, each group utilises quite different genetic triggers for sex determination. In mammals, testis development is initiated by action of the Y-chromosome gene SRY. Current evidence suggests that SRY may act together with a related gene, SOX9, to activate another gene(s) in the pathway of testicular differentiation. A downstream candidate for regulation by SRY and SOX9 is AMH. In mouse, Sox9 is expressed in the Sertoli cells of the embryonic testis and it precedes the onset of Amh expression. During mouse gonadogenesis, Amh is confined to the embryonic testis, although it later shows postnatal expression in the ovary. Reptiles such as the American alligator, which exhibit temperature-dependent sex determination (TSD) do not have dimorphic sex chromosomes and apparently no SRY orthologue. SOX9 is expressed during testis differentiation in the alligator; however, it appears to be expressed too late to cause testis determination. Here we describe the cloning and expression of the alligator AMH gene and show that AMH expression precedes SOX9 expression during testis differentiation. This is the opposite to that observed in the mouse where SOX9 precedes AMH expression. The data presented here, as well as findings from recent expression studies in the chick, suggest that AMH expression is not regulated by SOX9 in the non-mammalian vertebrates.

KW - Alligator

KW - Anti-Mullerian hormone

KW - Gonad differentiation

KW - SOX9

KW - Temperature-dependent sex determination

UR - http://www.scopus.com/inward/record.url?scp=0032739889&partnerID=8YFLogxK

M3 - Article

VL - 216

SP - 411

EP - 419

JO - Developmental Dynamics

JF - Developmental Dynamics

SN - 1058-8388

IS - 4-5

ER -