The nature of Brachury proteins explain the gut and posterior mesoderm characteristics of the kingdom animalia (Evans et al. 2012). that is, homogenous and heterogeneous animals. In cases where the Brachyury proteins fail to express themselves in the gut and posterior mesoderm, it means that those animals lost these T domain genes in the process of evolution. Brachyury proteins of the T domain are found in ascidians, cephalochordates, and hemichordates. Since they belong to the T domain, this gives DNA binding characteristic to the Brachyury proteins. According to Beddington, Rashbass and Wilson (1992: 159), the nature of the well known mouse mutant, Brachyury (T) in cloned mouse is revealed by its sequence, which is “an open reading frame of 436 amino acids”. In the blastocyst stage embryo, this T gene is present in the inner cell mass, which is then followed by the primordial stripe. Brachyury proteins can also be considered as transcriptional activators, because they have the ability to get attached to a 24-bp palindromic target sequence (Brody 1997, par. 24).
Beddington, R.S.P., Rashbass, P., & Wilson, V., 1992. Brachyury – a gene affecting mouse gastrulation and early organogenesis. Devclopmcni 1992 Supplement. [Online] Available at <. http://dev.biologists.org/content/116/Supplement/157.full.pdf>. [Accessed 20 April 2013]
Evans, A.L., Faial, T., Gilchrist, M.J., Down, T., Vallier, L., et al., 2012. Genomic targets of Brachyury (T) in differentiating mouse embryonic stem cells. PLoS ONE, vol.7, no.3, p. e33346.