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Development Leading (development + leading)
Selected AbstractsEmbryonic origin of mate choice in a lizard with temperature-dependent sex determinationDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2006Oliver Putz Abstract Individual differences in the adult sexual behavior of vertebrates are rooted in the fetal environment. In the leopard gecko (Eublepharis macularius), a species with temperature-dependent sex determination (TSD), hatchling sex ratios differ between incubation temperatures, as does sexuality in same-sex animals. This variation can primarily be ascribed to the temperature having direct organizing actions on the brain. Here we demonstrate that embryonic temperature can affect adult mate choice in the leopard gecko. Given the simultaneous choice between two females from different incubation temperatures (30.0 and 34.0°,C), males from one incubation temperature (30.0°,C) preferred the female from 34.0°,C, while males from another incubation temperature (32.5°,C) preferred the female from 30.0°,C. We suggest that this difference in mate choice is due to an environmental influence on brain development leading to differential perception of opposite-sex individuals. This previously unrecognized modulator of adult mate choice lends further support to the view that mate choice is best understood in the context of an individual's entire life-history. Thus, sexual selection results from a combination of the female's as well as the male's life history. Female attractiveness and male choice therefore are complementary. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 48: 29,38, 2006. [source] How Elephants are Opening Doors: Developmental Neuroethology, Attachment and Social ContextETHOLOGY, Issue 5 2007G. A. Bradshaw Ethology's renewed interest in developmental context coincides with recent insights from neurobiology and psychology on early attachment. Attachment and social learning are understood as fundamental mechanisms in development that shape core processes responsible for informing behaviour throughout a lifetime. Each field uniquely contributes to the creation of an integrated model and encourages dialogue between Tinbergen's four analytical levels: ethology in its underscoring of social systems of behaviour and context, psychology in its emphasis on socio-affective attachment transactions, and neuroscience in its explication of the coupled development of brain and behaviour. We review the relationship between developmental context and behaviour outcome as a topic shared by the three disciplines, with a specific focus on underlying neuroethological mechanisms. This interdisciplinary convergence is illustrated through the example of abnormal behaviour in wild African elephants (Loxodonta africana) that has been systematically observed in human-caused altered social contexts. Such disruptions impair normative socially mediated neuroendocrinological development leading to psychobiological dysregulation that expresses as non-normative behaviour. Aberrant behaviour in wild elephants provides a critical field example of what has been established in ex situ and clinical studies but has been largely absent in wild populations: a concrete link between effects of human disturbance on social context, and short- and long-term neuroethology. By so doing, it brings attention to the significant change in theories of behaviour that has been occurring across disciplines , namely, the merging of psychobiological and ethological perspectives into common, cross-species, human inclusive models. [source] Taphonomy and site formation on California's Channel IslandsGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 6 2006Torben C. Rick Inhabited by humans for over 12,000 calendar years, California's Channel Islands contain thousands of archaeological sites, ranging from dense shell middens and villages to small lithic scatters and camps. Similar to many islands around the world, the Channel Islands have a dearth of burrowing animals and limited historical development leading to generally good preservation of archaeological constituents and relatively high stratigraphic integrity. Despite these favorable preservation conditions, numerous natural and cultural processes have impacted the island's archaeological record. Channel Islands archaeologists, however, have given relatively limited attention to the effects of taphonomic and formation processes. The authors provide an overview of taphonomic and formation processes affecting Channel Islands archaeology, illustrating the importance of regional taphonomic syntheses in the management, preservation, and interpretation of archaeological sites. These data also demonstrate the significance of detailing formation processes in islands and other areas where burrowing rodents and other disturbances are thought to be absent or limited. © 2006 Wiley Periodicals, Inc. [source] Complement 3 deficiency impairs early pregnancy in miceMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 7 2009Wang-Ngai Chow Human oviductal cells produce complement-3 (C3) and its derivative, iC3b. These molecules are important in immune responses. Our recent study suggested that iC3b also possessed embryotrophic activity and it stimulates the blastulation and hatching rates of in vitro cultured mouse embryos. The objective is to study the impact of C3 deficiency on early pregnancy in vivo using homozygous C3-deficient (C3KO) and wild-type (C3WT) mice. C3 protein was undetectable in the reproductive tissues of C3KO mice. Deficiency in C3 is associated with significantly longer estrous cycle (P,=,0.037). No significant difference was found in the ovulation rate, total cell count in blastocysts and implantation rate between the wild-type and the C3KO mice, though C3KO mice tended to have lower values in the latter two parameters. On day 15 of pregnancy, C3KO mice had fewer conceptus (P,<,0.001) and higher resorption rate (P,<,0.001) than that of C3WT mice. The fetal and placental weights (P,<,0.001) were lower in the C3KO mice. The placenta of C3KO mice had smaller spongiotrophoblast (P,=,0.001) and labyrinth (P,=,0.037). Deficiency in C3 is associated with mild impairment in early pregnancy including longer estrous cycle and higher resorption rates after implantation. The impairment may be related to compromised placental development leading to under-developed fetuses. Mol. Reprod. Dev. 76: 647,655, 2009. © 2009 Wiley-Liss, Inc. [source] | ||||||||||