The adaptive role of amphibian oocyte melanic pigmentation and its molecular control are still elusive. Here we present evidence of a polymorphism in egg pigmentation in the emerald glass frog Espadarana prosoblepon. In Ecuadorian natural populations of this species, females can lay dark brown or pale eggs that develop into normal pigmented tadpoles and adults. This trait is a sex-limited phenotype that is inherited like a recessive allele that we called pale eggs like (pel). The pel phenotype is exclusive of oocyte cortical melanic pigmentation, which is reduced in comparison to wild type (wt) dark pigmented oocytes. https://www.selleckchem.com/products/pf-06463922.html Consequently, pel early embryos are paler in appearance, with reduced melanic pigmentation distributed to early blastomeres and embryonic ectoderm. However, these embryos form normal melanocyte derived pigmentation. Finally, we discuss the origin of this polymorphism and propose the use of E. prosoblepon as a model to study the adaptive role of egg pigmentation.Fish present remarkable malleability regarding gonadal sex fate. This phenotypic plasticity enables an organism to adapt changes in the environment by responding with different phenotypes. The gonad and the brain present this extraordinary plasticity. These organs are involved in the response to environmental stressors to direct the gonadal fate, inducing sex change or sex reversal in hermaphroditic and gonochoristic fish, respectively. The presence of such molecular and endocrine plasticity gives this group a large repertoire of possibilities against a continuously changing environment, resulting in the highest radiation of reproduction strategies described in vertebrates. In this review, we provide a broad and comparative view of tremendous radiation of sex determination mechanisms to direct gonadal fate. New results have established that the driving mechanism involves early response to environmental stressors by the brain plus high plasticity of gonadal differentiation and androgens as by-products of stress inactivation. In addition to the stress axis, another two major axes - the hypothalamic-pituitary-gonadal axis and the hypothalamic-pituitary-thyroid axis, which are well known to participate in the regulation of reproduction - have been proposed as reinforcing the brain-gonadal interrelationships in the fate of the gonad.Jorge E. Allende is a biochemist trained in the United States who has been a Professor at the University of Chile since 1961. He has served in many leadership positions in both Chilean and international scientific organizations and academic institutions. He led the International Cell Research Organization, the Latin American Network of Biological Sciences and obtained the Chilean National Science Prize. He belongs to the Chilean Academy of Sciences and is a foreign member of the U. S. National Academy of Sciences and also of the U.S. National Academy of Medicine. During his career, besides leading a highly successful research group, he was instrumental in generating an esprit de corps among Latin American scientists of all fields in biology starting in the late 1960's. He began a longstanding tradition by organizing advanced training courses for young scientists from the region who would not have otherwise had the opportunity to experience the latest methods and concepts in biological research, courses that had world leading researchers as instructors. A constant focus of his efforts consisted in promoting the establishment of postgraduate programs in biology throughout the continent, coordinating international funding programs aimed at scientific development in the third world and, more recently, advocating for science education among children and school teachers as the only way to achieve scientific literacy in our societies. In this interview, we explore how these issues were addressed by him and his counterparts in other Latin American countries, at a time when they had to start, essentially, from scratch.Alejandro Sánchez Alvarado represents a younger generation of Latin- American scientists that have achieved international scientific recognition (Fig. 1) .His work, together with those from other labs, has positioned the planaria Schmidtea mediterranea as a dynamic model system where the cellular and molecular basis of regeneration in metazoans can be probed. During his professional career he has established strong ties with Latin America, hosting and training students and participating in seminars, workshops and courses throughout the region. In this interview he discusses his early scientific development and training, and his views on various issues related to the professional development of young scientists.Development without a free-living tadpole is common among Ibero American frogs. The most derived condition is direct development where the tadpole has been eliminated, and the most investigated direct developing frog is Eleutherodactylus coqui. To provide a different point-of-view, an imaginary interview with a coqui is conducted. Opinions are offered on invasive species, developmental features that are surprisingly conserved, and novelty in germ layer specification.Claudio Stern was born in Montevideo, Uruguay where he received his school education. He moved to the United Kingdom at age 18. This interview briefly explores his trajectory from Uruguay, through universities in the UK (Sussex, UCL, Cambridge and Oxford) and USA (Columbia) and how he was influenced by various mentors and experiences.Roberto Mayor is a prominent Chilean developmental biologist working in the UK and an advocate of the developmental biology discipline in Latin America. Roberto started as a preimplantation mouse developmental biologist during his undergraduate and graduate studies in Chile. Yet, he now uses Xenopus and zebrafish to elucidate the mechanisms that drive the directed collective locomotion of neural crest cells. What life events moulded the research career of Roberto across the years? This article addresses this question and provides a personal perspective on his scientific achievements. The story of Roberto is a mix of turns and cycles that ultimately guided him to the migrating neural crest. Turns that made him shift between model organisms and scientific topics.Cycles that drove him back and forth between Chile and the UK and which have connected his early studies as an undergraduate student with the most recent work of his lab. A big lesson that we can learn from the life of Roberto is that no matter how much you plan your life always serendipity plays a significant role.