July 31, 2014

Do you ever feel nostalgic for a specific paper? Maybe this paper inspired your own research, or maybe it was a paper you immediately knew would be game-changing. Maybe, like today’s TBT paper, it was a great paper about solidly executed research with a memorable giggle-inducing technique. Thanks to a nostalgic HighMag reader and friend, Omar Quintero, we are being re-introduced to gonad sandwiches. 

In mammals, sex determination refers to the changes during early development that lead to the formation of either the testis or ovary. A gene on the Y chromosome called Sry initiates testis formation from the early bipotential gonad, including organizing Sertoli cells into the testis cord structure. In a 1997 paper, Martineau and colleagues investigated the early cell movements that occur after Sry expression, specifically the movement of nearby mesonephric cells to the genital ridge. To see these cell movements, Martineau and colleagues grafted a “blue” mesonephros from a mouse ubiquitously expressing β-galactosidase next to a “white” gonad from a different mouse. The movement of blue cells into the white gonad in these gonad sandwiches revealed that this movement is dependent on a signal induced by the male (XY) gonad that acts as a chemoattractant. Migration does not occur if an XX gonad is used in the sandwich, yet migration can occur whether an XY or XX mesonophros is used. The images above show the different XX and XY combinations used in these experiments, with XY gonads leading to extensive migration of blue cells. 

Martineau, J., Nordqvist, K., Tilmann, C., Lovell-Badge, R., & Capel, B. (1997). Male-specific cell migration into the developing gonad Current Biology, 7 (12), 958-968 DOI: 10.1016/S0960-9822(06)00415-5

Copyright ©1997 Elsevier Ltd. All rights reserved.

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