I appreciate the thoughtful comments by Eszter Szász and Balázs Rosivall on our article (Tagirov and Rutkowska 2013) and would like to respond to some of the issues raised and to clarify some, in my opinion, misunderstood points of our hypothesis.
The first argument of the authors is the lack of sufficient scientific data about the exact mechanism of gynandromorph formation.
Birds have become an especially popular model to study sex ratio (SR) manipulation.
The avian female is a heterogametic sex bearing 2 sex chromosomes, Z and W, and, therefore, producing 2 types of gametes, each of them with 1 sex chromosome. Some remarkably strong sex biases, such as sequential production of 20 male offspring in eggs laid by an individual female (Heinsohn et al.
First of all, I would like to note that in the absence of any reasonable hypotheses of mother’s control of offspring sex in birds, we propose a mechanistic model showing a possible path of events based on the known scientific facts and assumptions accepted in the scientific community.
I do not pretend that our hypothesis is an ultimate truth, but I do believe that it provides a starting point for discussion and a theoretical framework to plan experimental testing.
In the normal conditions, PBs and supernumerary male nuclei are pushed to the periphery of the active cytoplasm immediately after fertilization occurs, thus preventing their further development (Perry 1987).
He held a rake and a construction helmet so as to demonstrate that sex work is work just as any other, and nothing more.
For a while, he was the only participant present at the location and kept promising that the “girls will come shortly.
The starting point for our hypothesis was an article by Zhao et al.
(2010), where the authors, after comprehensive analysis of gynandromorphic chickens, concluded that “Our data establishing the presence of both ZZ- and ZW-containing cells indicate that it is highly unlikely that these birds arise as a consequence of mutation at the 2-cell stage of development, and would support the hypothesis that gynandromorphs arise as a result of failure of extrusion of a polar body (PB) during meiosis and subsequent fertilization of both a Z- and W-bearing female pronucleus” (Zhao et al. I acknowledge that we used this “accepted” idea originating from Hollander’s (1975) work to build our hypothesis.