Phenotype Image Detail

Image

Caption

Identification of the Map3k4^byg/Map3k4^byg (byg/byg) mutant. (A) Line RECB/31 (boygirl, byg) mutant embryo dissected during the screen at 13.5 dpc. The embryo shown here has exencephaly, spina bifida, and mild edema. On the mixed genetic background used for the forward genetic screen, the boygirl XY gonadal phenotypes observed at 13.5/14.5 dpc ranged from testis-shaped gonads that lacked cords (B), to testes with abnormal cord morphology and missing cords (arrowhead, C) through to XY gonads with an overt ovarian morphology (right, D). All gonads shown here were hybridised with a Sox9 probe to assess cord structure and differentiation of Sertoli cells. Note the higher than normal (with respect to ovary development) levels of Sox9 transcript in the boygirl XY ovary in (D) and the absence of Sox9 from the poles of this gonad (arrowheads, D), a characteristic of ovotestis development. Wild-type littermate gonads from unaffected XY and XX embryos are shown for comparison. (E-G) After further out-crossing of the byg mutation to C3H/HeH for mapping purposes, XY Map3k4^byg/Map3k4^byg gonads exhibited further signs of ovotestis formation. For example, expression of the germ cell marker Oct4 at 13.5 dpc revealed a cord-like pattern only in the centre of the gonad shown here (bracket, E), made clearer by sectioning (bracket, F). Note also the thickened capsule over the central testicular area. Control gonads exhibited robust cord formation throughout their length (G). (H) XX Map3k4^byg/Map3k4^byg gonads exhibited a normal pattern of Oct4 expression. (I) The poles of XY Map3k4^byg/Map3k4^byg gonads were also characterised by loss of male-specific genes, such as the Leydig cell marker 3b-HSD (bracket). (J) Abnormal expression of female-specific marker Wnt4 at the gonadal poles (arrowheads next to gonad on left) at 14.5 dpc. (K) Normal expression of Wnt4 in XX Map3k4^byg/Map3k4^byg gonad. (L) Absence of expression of meiotic marker Stra8 in wild-type XY gonad. (M) Prominent Stra8 expression in XX Map3k4^byg/Map3k4^byg gonad. (N) Expression of Stra8 at gonadal poles in XY Map3k4^byg/Map3k4^byg gonad (brackets).

Copyright

This image is from Bogani D, PLoS Biol 2009 Sep;7(9):e1000196, and is displayed under the terms of the Creative Commons Attribution 4.0 International License. J:153050

Associated Alleles

Symbol	Name
Map3k4^byg	mitogen-activated protein kinase kinase kinase 4; boygirl

Associated Genotypes

Allelic Composition	Genetic Background
Map3k4^byg/Map3k4^byg	involves: C3H/HeH * C57BL/6J